Tuesday, September 11, 2007
Swiss Interventional Study on Silent Ischaemia type I
Effects of anti-ischaemic drug therapy in silent myocardial ischaemia type I: the Swiss Interventional Study on Silent Ischaemia type I (SWISSI I): a randomized, controlled pilot study
Paul Erne1, Andreas W. Schoenenberger2, Michel Zuber1, Dieter Burckhardt3, Wolfgang Kiowski4, Paul Dubach5, Therese Resink3 and Matthias Pfisterer3,*
Aims: To determine the effect of anti-ischaemic drug therapy on long-term outcomes of asymptomatic patients without coronary artery disease (CAD) history but silent exercise ST-depression.
Methods and results: In a randomized multicentre trial, 263 of 522 asymptomatic subjects without CAD but at least one CAD risk factor in whom silent ischaemia by exercise ECG was confirmed by stress imaging were asked to participate. The 54 (21%) consenting patients were randomized to anti-anginal drug therapy in addition to risk factor control (MED, n = 26) or risk factor control-only (RFC, n = 28). They were followed yearly for 11.2 ± 2.2 years. During 483 patient-years, cardiac death, non-fatal myocardial infarction, or acute coronary syndrome requiring hospitalization or revascularization occurred in 3 (12%) of MED vs. 17 (61%) of RFC patients (P < 0.001). In addition, MED patients had consistently lower rates of exercise-induced ischaemia during follow-up, and left ventricular ejection fraction remained unchanged (–0.7%, P = 0.597) in contrast to RFC patients in whom it decreased over time (–6.0%, P = 0.006).
Conclusion: Anti-ischaemic drug therapy and aspirin seem to reduce cardiac events in subjects with asymptomatic ischaemia type I. In such patients, exercise-induced ST-segment depression should be verified by stress imaging; if silent ischaemia is documented, anti-ischaemic drug therapy and aspirin should be considered
Eur Heart J 2007; 28: 2110-2117
Commentaries:
Cohn Type I refers to asymptomatic individuals without known coronary artery disease (CAD) and Cohn Types II and III to patients with known CAD. Those with prior myocardial infarctions (MIs) who are asymptomatic are Type II, and those with CAD and both silent and symptomatic ischaemic episodes are Type III.1 In the last decade a dedicated group of Swiss cardiologists led by Dr Mathias Pfister of the Basel University Hospital have conducted a long-term series of clinical studies involving patients with Types I and II silent ischaemia. By providing a ‘new look’ at the syndrome of silent ischaemia they have contributed important clinical data to aid in its management. They have now described the results of anti-ischaemia drug therapy in Type I patients (studied in their SWISS I trial);2 their SWISS II data dealing with Type 2 patients and also recently published3 will be commented on later in this editorial.
Traditional risk factors fail to explain over half of CHD risk in overweight people
Traditional risk factors fail to explain over half of CHD risk in overweight people
11 September 2007
MedWire News: Blood pressure and cholesterol levels explain less than half of the excess risk for coronary heart disease (CHD) in people who are overweight or obese, results of a meta-analysis suggest.
"This implies that, even under the theoretical scenario that optimal treatment would be available against hypertension and hypercholesterolemia in overweight persons, they still would have an elevated risk of CHD," say the researchers.
Writing in the Archives of Internal Medicine, Rik Bogers (National Institute for Public Health and the Environment, Bilthoven, The Netherlands) and colleagues list several mechanisms that could contribute to the increased CHD risk in overweight people.
These include low-grade inflammation, endothelial dysfunction, a tendency toward coagulation, and left ventricular hypertrophy.
"Obviously, overweight is associated with increased risk of Type 2 diabetes mellitus," they add.
The findings emerge from a collaborative meta-analysis involving investigators from 31 prospective cohort studies, including large studies such as the Nurses' Health Study, the Norwegian Counties Study, and the Whitehall Study.
This provided data on 302,296 people who suffered 18,000 CHD events. CHD risk was assessed in relation to body mass index (BMI) categories for 14 cohorts and in relation to BMI as a continuous variable for 21 cohorts.
Overweight people (BMI 25.0-29.9) had a relative risk for CHD of 1.32, compared with normal-weight people, after accounting for age, gender, physical activity, and smoking status.
The corresponding relative risk in obese people (BMI ≥30.0) was 1.81.
Accounting for blood pressure and cholesterol levels reduced the relative risks for CHD to 1.17 and 1.49 for overweight and obese people, respectively, compared with normal-weight people.
Thus, blood pressure and cholesterol levels accounted for 47% and 40% of the excess CHD risk associated with overweight and obesity, respectively.
Each 5-unit increase in BMI increased CHD risk 1.29 fold before accounting for blood pressure and cholesterol levels, and 1.16 fold after allowing for these risk factors.
"Even moderate overweight is associated with increased risk of CHD," the researchers stress.
"Because high blood pressure and cholesterol levels are plausible intermediary factors in the causal pathways linking overweight and CHD, adjusting for them in epidemiological analyses certainly results in underestimating the total public health impact of overweight."
Arch Intern Med 2007; 167: 1720-1728
11 September 2007
MedWire News: Blood pressure and cholesterol levels explain less than half of the excess risk for coronary heart disease (CHD) in people who are overweight or obese, results of a meta-analysis suggest.
"This implies that, even under the theoretical scenario that optimal treatment would be available against hypertension and hypercholesterolemia in overweight persons, they still would have an elevated risk of CHD," say the researchers.
Writing in the Archives of Internal Medicine, Rik Bogers (National Institute for Public Health and the Environment, Bilthoven, The Netherlands) and colleagues list several mechanisms that could contribute to the increased CHD risk in overweight people.
These include low-grade inflammation, endothelial dysfunction, a tendency toward coagulation, and left ventricular hypertrophy.
"Obviously, overweight is associated with increased risk of Type 2 diabetes mellitus," they add.
The findings emerge from a collaborative meta-analysis involving investigators from 31 prospective cohort studies, including large studies such as the Nurses' Health Study, the Norwegian Counties Study, and the Whitehall Study.
This provided data on 302,296 people who suffered 18,000 CHD events. CHD risk was assessed in relation to body mass index (BMI) categories for 14 cohorts and in relation to BMI as a continuous variable for 21 cohorts.
Overweight people (BMI 25.0-29.9) had a relative risk for CHD of 1.32, compared with normal-weight people, after accounting for age, gender, physical activity, and smoking status.
The corresponding relative risk in obese people (BMI ≥30.0) was 1.81.
Accounting for blood pressure and cholesterol levels reduced the relative risks for CHD to 1.17 and 1.49 for overweight and obese people, respectively, compared with normal-weight people.
Thus, blood pressure and cholesterol levels accounted for 47% and 40% of the excess CHD risk associated with overweight and obesity, respectively.
Each 5-unit increase in BMI increased CHD risk 1.29 fold before accounting for blood pressure and cholesterol levels, and 1.16 fold after allowing for these risk factors.
"Even moderate overweight is associated with increased risk of CHD," the researchers stress.
"Because high blood pressure and cholesterol levels are plausible intermediary factors in the causal pathways linking overweight and CHD, adjusting for them in epidemiological analyses certainly results in underestimating the total public health impact of overweight."
Arch Intern Med 2007; 167: 1720-1728
Saturday, September 8, 2007
New CPR promises better results by compressing abdomen, not chest...
New CPR Technique Advocated: An Abdominal Approach
A new method of administering cardiopulmonary resuscitation is being proposed by a Purdue professor of biomedicine. The new technique focuses on applying pressure to the abdomen rather than the chest, and according to the research, the study "provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries," all while reducing the chances of damage to the rib cage.
Instead of two breaths for every 30 chest compressions, the new procedure provides a breath for every abdominal compression because pushing on the abdomen depresses the diaphragm toward the head, expelling air from the lungs. The release of force causes inhalation.
Researchers have known since the 1980s that pushing on the abdomen circulates blood through the heart. The idea was originated by Purdue nursing doctoral student Sandra Ralston, Geddes said [Leslie Geddes, the Showalter Distinguished Professor Emeritus in Purdue's Weldon School of Biomedical Engineering --ed].
"She made the remarkable observation that if you pushed on the abdomen after each chest compression you could double the CPR blood flow," he said. "So I started thinking, what would happen if you just pushed on the abdomen and eliminated chest compression entirely?"
The procedure provides a new way to effectively perform "coronary perfusion," or pumping blood through the heart muscle, which is critical for successful resuscitation because the heart muscle is nourished by oxygenated blood, Geddes said.
"Unfortunately, in standard chest-compression CPR, blood sometimes flows in the wrong direction, which means the coronary blood flow goes backward, bringing de-oxygenated blood back into the heart muscle," Geddes said. "This retrograde flow reduces the likelihood of resuscitation."
Findings showed that OAC-CPR eliminates this backward flow.
The Purdue researchers compared coronary artery blood flow during standard chest-compression CPR with the flow resulting from only abdominal compression CPR. Findings showed that using the new method and pushing with the same force recommended for standard CPR provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries.
The researchers followed the standard recommended by the American Heart Association, pushing with 100 pounds of pressure 100 times per minute.
"With OAC-CPR, you really don't have to press as hard or as often, but we followed the American Heart Association standard to avoid possible criticism from people who could have said we didn't observe the standard," Geddes said.
Another benefit of OAC-CPR is that it eliminates rib fractures, which are commonly caused by compressing the chest. Rib fractures cause the chest to recoil more slowly, but effective CPR requires that rescuers wait until the chest recoils fully before compressing.
Geddes created a wooden "pressure applicator" that resembles a scaled-down version of a baseball home plate. It is contoured so that it can be used to compress the abdomen without pushing on the ribs. However, a rescuer could push with the hands to perform the procedure if no applicator were available.
Purdue Press Release: New CPR promises better results by compressing abdomen, not chest...
A new method of administering cardiopulmonary resuscitation is being proposed by a Purdue professor of biomedicine. The new technique focuses on applying pressure to the abdomen rather than the chest, and according to the research, the study "provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries," all while reducing the chances of damage to the rib cage.
Instead of two breaths for every 30 chest compressions, the new procedure provides a breath for every abdominal compression because pushing on the abdomen depresses the diaphragm toward the head, expelling air from the lungs. The release of force causes inhalation.
Researchers have known since the 1980s that pushing on the abdomen circulates blood through the heart. The idea was originated by Purdue nursing doctoral student Sandra Ralston, Geddes said [Leslie Geddes, the Showalter Distinguished Professor Emeritus in Purdue's Weldon School of Biomedical Engineering --ed].
"She made the remarkable observation that if you pushed on the abdomen after each chest compression you could double the CPR blood flow," he said. "So I started thinking, what would happen if you just pushed on the abdomen and eliminated chest compression entirely?"
The procedure provides a new way to effectively perform "coronary perfusion," or pumping blood through the heart muscle, which is critical for successful resuscitation because the heart muscle is nourished by oxygenated blood, Geddes said.
"Unfortunately, in standard chest-compression CPR, blood sometimes flows in the wrong direction, which means the coronary blood flow goes backward, bringing de-oxygenated blood back into the heart muscle," Geddes said. "This retrograde flow reduces the likelihood of resuscitation."
Findings showed that OAC-CPR eliminates this backward flow.
The Purdue researchers compared coronary artery blood flow during standard chest-compression CPR with the flow resulting from only abdominal compression CPR. Findings showed that using the new method and pushing with the same force recommended for standard CPR provided 25 percent more blood flow through the heart muscle without retrograde flow in the coronary arteries.
The researchers followed the standard recommended by the American Heart Association, pushing with 100 pounds of pressure 100 times per minute.
"With OAC-CPR, you really don't have to press as hard or as often, but we followed the American Heart Association standard to avoid possible criticism from people who could have said we didn't observe the standard," Geddes said.
Another benefit of OAC-CPR is that it eliminates rib fractures, which are commonly caused by compressing the chest. Rib fractures cause the chest to recoil more slowly, but effective CPR requires that rescuers wait until the chest recoils fully before compressing.
Geddes created a wooden "pressure applicator" that resembles a scaled-down version of a baseball home plate. It is contoured so that it can be used to compress the abdomen without pushing on the ribs. However, a rescuer could push with the hands to perform the procedure if no applicator were available.
Purdue Press Release: New CPR promises better results by compressing abdomen, not chest...
Friday, September 7, 2007
Metformin linked to reduced mortality in diabetic patients with HF
Metformin linked to reduced mortality in diabetic patients with HF
7 September 2007
MedWire News: Metformin is associated with reduced mortality in patients with heart failure (HF) and diabetes, Canadian researchers report in the British Medical Journal.
HF is common in diabetic patients, but few studies have compared the effect of antidiabetic drugs in patients with both conditions, the authors say.
Jeffrey Johnson, from the University of Alberta in Edmonton, and colleagues therefore carried out a meta-analysis of eight studies to evaluate the effects of antidiabetic agents in patients with HF and diabetes.
Four studies evaluated the effect of insulin treatment, three examined metformin, four evaluated thiazolidinediones, and two studies compared sulfonylureas with other agents.
Insulin use was associated with increased risk for all cause mortality in studies that did not adjust for diet and antidiabetic drug treatment (odds ratio [OR]=1.25), and in the studies that accounted for these factors (hazard ratio [HR]=1.66).
In addition, metformin was not associated with increased hospital admission at 1 year for any cause (HR=0.94) or for HF (HR=0.92). The pooled effect suggested that treatment with metformin might be linked to a reduced all cause hospital admission at 1 year (pooled OR=0.85).
Thiazolidinediones were associated with reduced all cause mortality (pooled OR=0.83), but they were also linked to an increased risk for hospital admission for HF (pooled OR=0.83). The researchers note that this conflicting result might be due to differences in comparator treatments.
Johnson and co-workers conclude: "Our analysis revealed that treatment with metformin may be associated with lower mortality rates."
Nevertheless, they note that the US Food and Drug Administration still recommends cautious use of metformin in this population.
Br Med J 2007; 335: 497
7 September 2007
MedWire News: Metformin is associated with reduced mortality in patients with heart failure (HF) and diabetes, Canadian researchers report in the British Medical Journal.
HF is common in diabetic patients, but few studies have compared the effect of antidiabetic drugs in patients with both conditions, the authors say.
Jeffrey Johnson, from the University of Alberta in Edmonton, and colleagues therefore carried out a meta-analysis of eight studies to evaluate the effects of antidiabetic agents in patients with HF and diabetes.
Four studies evaluated the effect of insulin treatment, three examined metformin, four evaluated thiazolidinediones, and two studies compared sulfonylureas with other agents.
Insulin use was associated with increased risk for all cause mortality in studies that did not adjust for diet and antidiabetic drug treatment (odds ratio [OR]=1.25), and in the studies that accounted for these factors (hazard ratio [HR]=1.66).
In contrast, all cause mortality was significantly lower in patients treated with metformin, at a HR of 0.86 compared with other antidiabetic drugs and insulin, and at a HR of 0.70 compared with sulfonylureas.
In addition, metformin was not associated with increased hospital admission at 1 year for any cause (HR=0.94) or for HF (HR=0.92). The pooled effect suggested that treatment with metformin might be linked to a reduced all cause hospital admission at 1 year (pooled OR=0.85).
Thiazolidinediones were associated with reduced all cause mortality (pooled OR=0.83), but they were also linked to an increased risk for hospital admission for HF (pooled OR=0.83). The researchers note that this conflicting result might be due to differences in comparator treatments.
Johnson and co-workers conclude: "Our analysis revealed that treatment with metformin may be associated with lower mortality rates."
Nevertheless, they note that the US Food and Drug Administration still recommends cautious use of metformin in this population.
Br Med J 2007; 335: 497
Electrocardiography / Left Ventricular Hypertrophy / Arterial hypertension: Systematic Review
Accuracy of electrocardiography in diagnosis of left ventricular hypertrophy in arterial hypertension: systematic review
BMJ, doi:10.1136/bmj.39276.636354.AE (published 28 August 2007)
Research
Correspondence to: M Egger egger@ispm.unibe.ch
Objective To review the accuracy of electrocardiography in screening for left ventricular hypertrophy in patients with hypertension.
Design Systematic review of studies of test accuracy of six electrocardiographic indexes: the Sokolow-Lyon index, Cornell voltage index, Cornell product index, Gubner index, and Romhilt-Estes scores with thresholds for a positive test of 4 points or 5 points.
Data sources Electronic databases ((Pre-)Medline, Embase), reference lists of relevant studies and previous reviews, and experts.
Study selection Two reviewers scrutinised abstracts and examined potentially eligible studies. Studies comparing the electrocardiographic index with echocardiography in hypertensive patients and reporting sufficient data were included.
Data extraction Data on study populations, echocardiographic criteria, and methodological quality of studies were extracted.
Data synthesis Negative likelihood ratios, which indicate to what extent the posterior odds of left ventricular hypertrophy is reduced by a negative test, were calculated.
Results 21 studies and data on 5608 patients were analysed. The median prevalence of left ventricular hypertrophy was 33% (interquartile range 23-41%) in primary care settings (10 studies) and 65% (37-81%) in secondary care settings (11 studies). The median negative likelihood ratio was similar across electrocardiographic indexes, ranging from 0.85 (range 0.34-1.03) for the Romhilt-Estes score (with threshold 4 points) to 0.91 (0.70-1.01) for the Gubner index. Using the Romhilt-Estes score in primary care, a negative electrocardiogram result would reduce the typical pre-test probability from 33% to 31%. In secondary care the typical pre-test probability of 65% would be reduced to 63%.
Conclusion Electrocardiographic criteria should not be used to rule out left ventricular hypertrophy in patients with hypertension.
BMJ, doi:10.1136/bmj.39276.636354.AE (published 28 August 2007)
Research
Correspondence to: M Egger egger@ispm.unibe.ch
Objective To review the accuracy of electrocardiography in screening for left ventricular hypertrophy in patients with hypertension.
Design Systematic review of studies of test accuracy of six electrocardiographic indexes: the Sokolow-Lyon index, Cornell voltage index, Cornell product index, Gubner index, and Romhilt-Estes scores with thresholds for a positive test of 4 points or 5 points.
Data sources Electronic databases ((Pre-)Medline, Embase), reference lists of relevant studies and previous reviews, and experts.
Study selection Two reviewers scrutinised abstracts and examined potentially eligible studies. Studies comparing the electrocardiographic index with echocardiography in hypertensive patients and reporting sufficient data were included.
Data extraction Data on study populations, echocardiographic criteria, and methodological quality of studies were extracted.
Data synthesis Negative likelihood ratios, which indicate to what extent the posterior odds of left ventricular hypertrophy is reduced by a negative test, were calculated.
Results 21 studies and data on 5608 patients were analysed. The median prevalence of left ventricular hypertrophy was 33% (interquartile range 23-41%) in primary care settings (10 studies) and 65% (37-81%) in secondary care settings (11 studies). The median negative likelihood ratio was similar across electrocardiographic indexes, ranging from 0.85 (range 0.34-1.03) for the Romhilt-Estes score (with threshold 4 points) to 0.91 (0.70-1.01) for the Gubner index. Using the Romhilt-Estes score in primary care, a negative electrocardiogram result would reduce the typical pre-test probability from 33% to 31%. In secondary care the typical pre-test probability of 65% would be reduced to 63%.
Conclusion Electrocardiographic criteria should not be used to rule out left ventricular hypertrophy in patients with hypertension.
Advantages and Disadvantages of Alcohol Intake on Cardiovascular Health Reviewed
Advantages and Disadvantages of Alcohol Intake on Cardiovascular Health Reviewed
Study Highlights
In general, alcohol consumption creates a J-shaped curve in terms of the risk for myocardial infarction and total mortality. Consumption of 1 drink daily in women and 1 to 2 drinks daily in men has been demonstrated to reduce rates of total mortality by 18% vs abstinence, although the risk for mortality rises with heavy use of alcohol. Light to moderate drinking also reduces the risk for CHD events by 30% to 35% vs abstinence.
Alcohol use seems effective in reducing cardiovascular outcomes regardless of sex or age. Even among men with a healthy lifestyle, alcohol can reduce the risk for myocardial infarction by up to 50%.
Light to moderate alcohol consumption seems to be beneficial among patients with hypertension, although alcohol can increase blood pressure in a dose-dependent fashion, and heavier drinking may be particularly harmful for these patients. Alcohol also seems to reduce the risk for CHD among patients with diabetes.
Alcohol use also creates a J-shaped curve with regard to the risk for stroke and dementia, and alcohol consumption has been associated with a reduced risk for peripheral arterial disease.
Alcohol may also improve other significant cardiovascular risk factors. Drinking 1 to 2 alcoholic beverages per day can reduce the incidence of diabetes by 30%, and regular light alcohol consumption also reduces the risk of developing the metabolic syndrome.
It seems that the ethanol itself, rather than the type of drink consumed, is the component most responsible for the health benefits of alcoholic beverages.
Despite the benefits of light to moderate alcohol consumption, binge drinking is associated with a 2-fold increase in the risk for myocardial infarction and mortality vs with abstinence from alcohol. Therefore, the most cardiovascular protection seems to be derived from 1 drink per day among women and 1 to 2 drinks per day among men.
Nonetheless, the study authors do not recommend regular use of alcohol to prevent cardiovascular disease. They note that alcohol abuse is the third leading cause of preventable death in the United States and that encouraging regular use of alcohol may contribute more cases to this already significant problem.
Alcohol may improve the risk for cardiovascular disease through increasing the concentration of HDL cholesterol. Alcohol seems to increase HDL cholesterol in a dose-dependent fashion, with an average increase of 5% in HDL cholesterol among adults who consume 1 alcoholic beverage per day vs adults who abstain. In addition, alcohol can improve insulin sensitivity, particularly when consumed immediately before or during eating. Finally, alcohol can reduce intravascular inflammation and abdominal obesity, both of which promote cardiovascular events.
Clinical Context
The current review by O'Keefe and colleagues describes the evidence for alcohol in improving cardiovascular health.
Pearls for Practice
Alcohol can improve cardiovascular outcomes primarily by increasing HDL cholesterol and improving insulin sensitivity and abdominal obesity.
The current review suggests that light to moderate use of alcohol can help improve rates of total mortality, myocardial infarction, stroke, peripheral arterial disease, diabetes, and the metabolic syndrome. However, because of the high rate of preventable deaths associated with alcohol use, the study authors recommend against the universal prescription of alcohol consumption.
Study Highlights
In general, alcohol consumption creates a J-shaped curve in terms of the risk for myocardial infarction and total mortality. Consumption of 1 drink daily in women and 1 to 2 drinks daily in men has been demonstrated to reduce rates of total mortality by 18% vs abstinence, although the risk for mortality rises with heavy use of alcohol. Light to moderate drinking also reduces the risk for CHD events by 30% to 35% vs abstinence.
Alcohol use seems effective in reducing cardiovascular outcomes regardless of sex or age. Even among men with a healthy lifestyle, alcohol can reduce the risk for myocardial infarction by up to 50%.
Light to moderate alcohol consumption seems to be beneficial among patients with hypertension, although alcohol can increase blood pressure in a dose-dependent fashion, and heavier drinking may be particularly harmful for these patients. Alcohol also seems to reduce the risk for CHD among patients with diabetes.
Alcohol use also creates a J-shaped curve with regard to the risk for stroke and dementia, and alcohol consumption has been associated with a reduced risk for peripheral arterial disease.
Alcohol may also improve other significant cardiovascular risk factors. Drinking 1 to 2 alcoholic beverages per day can reduce the incidence of diabetes by 30%, and regular light alcohol consumption also reduces the risk of developing the metabolic syndrome.
It seems that the ethanol itself, rather than the type of drink consumed, is the component most responsible for the health benefits of alcoholic beverages.
Despite the benefits of light to moderate alcohol consumption, binge drinking is associated with a 2-fold increase in the risk for myocardial infarction and mortality vs with abstinence from alcohol. Therefore, the most cardiovascular protection seems to be derived from 1 drink per day among women and 1 to 2 drinks per day among men.
Nonetheless, the study authors do not recommend regular use of alcohol to prevent cardiovascular disease. They note that alcohol abuse is the third leading cause of preventable death in the United States and that encouraging regular use of alcohol may contribute more cases to this already significant problem.
Alcohol may improve the risk for cardiovascular disease through increasing the concentration of HDL cholesterol. Alcohol seems to increase HDL cholesterol in a dose-dependent fashion, with an average increase of 5% in HDL cholesterol among adults who consume 1 alcoholic beverage per day vs adults who abstain. In addition, alcohol can improve insulin sensitivity, particularly when consumed immediately before or during eating. Finally, alcohol can reduce intravascular inflammation and abdominal obesity, both of which promote cardiovascular events.
Clinical Context
The current review by O'Keefe and colleagues describes the evidence for alcohol in improving cardiovascular health.
Pearls for Practice
Alcohol can improve cardiovascular outcomes primarily by increasing HDL cholesterol and improving insulin sensitivity and abdominal obesity.
The current review suggests that light to moderate use of alcohol can help improve rates of total mortality, myocardial infarction, stroke, peripheral arterial disease, diabetes, and the metabolic syndrome. However, because of the high rate of preventable deaths associated with alcohol use, the study authors recommend against the universal prescription of alcohol consumption.
Study Suggests How Two Diabetes Drugs May Exacerbate Heart Failure
Teaching Brief® - MedPage Today
Study Suggests How Two Diabetes Drugs May Exacerbate Heart Failure
ReviewNEW YORK, Sept. 6 -- Experiments in mice suggest that the type 2 diabetes drugs rosiglitazone (Avandia) and pioglitazone (Actos) increase uptake of both glucose and triglycerides in cardiac tissue, causing or exacerbating heart failure.
Primary source: Journal of Clinical InvestigationSource reference: Goldberg IJ et al. "Cardiomyocyte expression of PPARγ leads to cardiac dysfunction in mice." J. Clin. Invest. doi:10.1172/JCI30335.
The study was funded by grants from the Specialized Centers of Clinically Oriented Research and the National Heart, Lung, and Blood Institute. The authors reported that they had no conflicts of interest.
MedPage Today Action Points
Explain to patients who ask that both Avandia and Actos may increase the risk of heart failure and are contraindicated in patients with New York Heart Association stage III or IV heart failure.
Study Suggests How Two Diabetes Drugs May Exacerbate Heart Failure
ReviewNEW YORK, Sept. 6 -- Experiments in mice suggest that the type 2 diabetes drugs rosiglitazone (Avandia) and pioglitazone (Actos) increase uptake of both glucose and triglycerides in cardiac tissue, causing or exacerbating heart failure.
Primary source: Journal of Clinical InvestigationSource reference: Goldberg IJ et al. "Cardiomyocyte expression of PPARγ leads to cardiac dysfunction in mice." J. Clin. Invest. doi:10.1172/JCI30335.
The study was funded by grants from the Specialized Centers of Clinically Oriented Research and the National Heart, Lung, and Blood Institute. The authors reported that they had no conflicts of interest.
MedPage Today Action Points
Explain to patients who ask that both Avandia and Actos may increase the risk of heart failure and are contraindicated in patients with New York Heart Association stage III or IV heart failure.
Thursday, September 6, 2007
Medicine Residents' Understanding of the Biostatistics and Results in the Medical Literature
Medicine Residents' Understanding of the Biostatistics and Results in the Medical Literature
Donna M. Windish, MD, MPH; Stephen J. Huot, MD, PhD; Michael L. Green, MD, MSc
JAMA. 2007;298:1010-1022.
Context Physicians depend on the medical literature to keep current with clinical information. Little is known about residents' ability to understand statistical methods or how to appropriately interpret research outcomes.
Objective To evaluate residents' understanding of biostatistics and interpretation of research results.
Design, Setting, and Participants Multiprogram cross-sectional survey of internal medicine residents.
Main Outcome Measure Percentage of questions correct on a biostatistics/study design multiple-choice knowledge test.
Results The survey was completed by 277 of 367 residents (75.5%) in 11 residency programs. The overall mean percentage correct on statistical knowledge and interpretation of results was 41.4% (95% confidence interval [CI], 39.7%-43.3%) vs 71.5% (95% CI, 57.5%-85.5%) for fellows and general medicine faculty with research training (P < .001). Higher scores in residents were associated with additional advanced degrees (50.0% [95% CI, 44.5%-55.5%] vs 40.1% [95% CI, 38.3%-42.0%]; P < .001); prior biostatistics training (45.2% [95% CI, 42.7%-47.8%] vs 37.9% [95% CI, 35.4%-40.3%]; P = .001); enrollment in a university-based training program (43.0% [95% CI, 41.0%-45.1%] vs 36.3% [95% CI, 32.6%-40.0%]; P = .002); and male sex (44.0% [95% CI, 41.4%-46.7%] vs 38.8% [95% CI, 36.4%-41.1%]; P = .004). On individual knowledge questions, 81.6% correctly interpreted a relative risk. Residents were less likely to know how to interpret an adjusted odds ratio from a multivariate regression analysis (37.4%) or the results of a Kaplan-Meier analysis (10.5%). Seventy-five percent indicated they did not understand all of the statistics they encountered in journal articles, but 95% felt it was important to understand these concepts to be an intelligent reader of the literature.
Conclusions Most residents in this study lacked the knowledge in biostatistics needed to interpret many of the results in published clinical research. Residency programs should include more effective biostatistics training in their curricula to successfully prepare residents for this important lifelong learning skill.
Donna M. Windish, MD, MPH; Stephen J. Huot, MD, PhD; Michael L. Green, MD, MSc
JAMA. 2007;298:1010-1022.
Context Physicians depend on the medical literature to keep current with clinical information. Little is known about residents' ability to understand statistical methods or how to appropriately interpret research outcomes.
Objective To evaluate residents' understanding of biostatistics and interpretation of research results.
Design, Setting, and Participants Multiprogram cross-sectional survey of internal medicine residents.
Main Outcome Measure Percentage of questions correct on a biostatistics/study design multiple-choice knowledge test.
Results The survey was completed by 277 of 367 residents (75.5%) in 11 residency programs. The overall mean percentage correct on statistical knowledge and interpretation of results was 41.4% (95% confidence interval [CI], 39.7%-43.3%) vs 71.5% (95% CI, 57.5%-85.5%) for fellows and general medicine faculty with research training (P < .001). Higher scores in residents were associated with additional advanced degrees (50.0% [95% CI, 44.5%-55.5%] vs 40.1% [95% CI, 38.3%-42.0%]; P < .001); prior biostatistics training (45.2% [95% CI, 42.7%-47.8%] vs 37.9% [95% CI, 35.4%-40.3%]; P = .001); enrollment in a university-based training program (43.0% [95% CI, 41.0%-45.1%] vs 36.3% [95% CI, 32.6%-40.0%]; P = .002); and male sex (44.0% [95% CI, 41.4%-46.7%] vs 38.8% [95% CI, 36.4%-41.1%]; P = .004). On individual knowledge questions, 81.6% correctly interpreted a relative risk. Residents were less likely to know how to interpret an adjusted odds ratio from a multivariate regression analysis (37.4%) or the results of a Kaplan-Meier analysis (10.5%). Seventy-five percent indicated they did not understand all of the statistics they encountered in journal articles, but 95% felt it was important to understand these concepts to be an intelligent reader of the literature.
Conclusions Most residents in this study lacked the knowledge in biostatistics needed to interpret many of the results in published clinical research. Residency programs should include more effective biostatistics training in their curricula to successfully prepare residents for this important lifelong learning skill.
Dronedarone for Maintenance of Sinus Rhythm in Atrial Fibrillation or Flutter
Dronedarone for Maintenance of Sinus Rhythm
in Atrial Fibrillation or Flutter
NEW ENGLAND JOURNAL OF MEDICINE
Volume 357 — September 6, 2007 — Number 10
Bramah N. Singh, M.D., D.Sc., Stuart J. Connolly, M.D., Harry J.G.M. Crijns, M.D., Denis Roy, M.D., Peter R. Kowey, M.D., Alessandro Capucci, M.D., Ph.D., David Radzik, M.D., Etienne M. Aliot, M.D., Stefan H. Hohnloser, M.D., for the EURIDIS and ADONIS Investigators
ABSTRACT
Background Amiodarone is effective in maintaining sinus rhythm in atrial fibrillation but is associated with potentially serious toxic effects. Dronedarone is a new antiarrhythmic agent pharmacologically related to amiodarone but developed to reduce the risk of side effects.
Methods In two identical multicenter, double-blind, randomized trials, one conducted in Europe (ClinicalTrials.gov number, NCT00259428 [ClinicalTrials.gov] ) and one conducted in the United States, Canada, Australia, South Africa, and Argentina (termed the non-European trial, NCT00259376 [ClinicalTrials.gov] ), we evaluated the efficacy of dronedarone, with 828 patients receiving 400 mg of the drug twice daily and 409 patients receiving placebo. Rhythm was monitored transtelephonically on days 2, 3, and 5; at 3, 5, 7, and 10 months; during recurrence of arrhythmia; and at nine scheduled visits during a 12-month period. The primary end point was the time to the first recurrence of atrial fibrillation or flutter.
Results In the European trial, the median times to the recurrence of arrhythmia were 41 days in the placebo group and 96 days in the dronedarone group (P=0.01). The corresponding durations in the non-European trial were 59 and 158 days (P=0.002). At the recurrence of arrhythmia in the European trial, the mean (±SD) ventricular rate was 117.5±29.1 beats per minute in the placebo group and 102.3±24.7 beats per minute in the dronedarone group (P<0.001); the corresponding rates in the non-European trial were 116.6±31.9 and 104.6±27.1 beats per minute (P<0.001). Rates of pulmonary toxic effects and of thyroid and liver dysfunction were not significantly increased in the dronedarone group.
Conclusions Dronedarone was significantly more effective than placebo in maintaining sinus rhythm and in reducing the ventricular rate during recurrence of arrhythmia.
LINK: http://content.nejm.org/cgi/content/short/357/10/987
Wednesday, September 5, 2007
Consent bias may reduce value of observational research
Consent bias may reduce value of observational research
By Liam Davenport
05 September 2007
Heart 2007; 93: 1116-1120
MedWire News: Consent bias may impact on observational research into ischemic heart disease, with clinically important prognostic variables associated with consent preferences, say Irish researchers.
Patients' right to privacy and confidentiality has been increasingly acknowledged in recent years. Although the implications of prior written consent have been discussed in terms of healthcare professionals, public attitudes have not been widely examined, and what research has been conducted has yielded mixed results.
Researchers have expressed concerns over the potential constraints of strict consent rules on observational research, so Brian Buckley, from the National University of Ireland in Galway, and colleagues sought to determine differences between adults who consent to participating in such research and those who do not.
They examined data on a representative cohort of 1609 patients with ischemic heart disease from 35 randomized general practices identified in 2001. Baseline questionnaires were sent to 1269 participants, with follow-up medical charts up to the years 2005-2006 located for 1592 patients.
In all, 876 (69%) of the questionnaires were returned completed. Of these, 574 (65.5%) gave consent for their participation in further research, the team reports in the journal Heart.
Multiple logistic regression analysis revealed that patients were more likely to consent to participation in further research if the factors they had undergone prior percutaneous transluminal coronary angioplasty, a last recorded blood pressure of less than 140/90 mmHg, a last recorded total cholesterol level of less than 5 mmol/l, and were an ex-smoker, as opposed to a current or non-smoker, at respective odds ratios of 1.77, 1.45, 1.71, and 1.73.
The team says: "The implication is that if cohorts in the future are dependent upon prior written consent they are likely to contain disproportionate numbers of those who have made healthy lifestyle decisions, who have previously benefited from healthcare, or those whose clinical risk factors are already well managed.
"This may have two serious consequences: first, the generalizability of observational research will be reduced; second, the effects of treatments may be variously overestimated or underestimated if those who are most unwell or are not making healthy lifestyle decisions are under-represented in study populations."
In an accompanying editorial, Cornelia Junghans and Melvyn Jones, from Royal Free and University College London Medical School in the UK, write: "Possibly, the public may decide that individual privacy is more important than the societal benefits of research, once an open debate has taken place.
"In this case, patient education may be the only way forward to ensure adequate and unbiased participation in research."
Free abstract
By Liam Davenport
05 September 2007
Heart 2007; 93: 1116-1120
MedWire News: Consent bias may impact on observational research into ischemic heart disease, with clinically important prognostic variables associated with consent preferences, say Irish researchers.
Patients' right to privacy and confidentiality has been increasingly acknowledged in recent years. Although the implications of prior written consent have been discussed in terms of healthcare professionals, public attitudes have not been widely examined, and what research has been conducted has yielded mixed results.
Researchers have expressed concerns over the potential constraints of strict consent rules on observational research, so Brian Buckley, from the National University of Ireland in Galway, and colleagues sought to determine differences between adults who consent to participating in such research and those who do not.
They examined data on a representative cohort of 1609 patients with ischemic heart disease from 35 randomized general practices identified in 2001. Baseline questionnaires were sent to 1269 participants, with follow-up medical charts up to the years 2005-2006 located for 1592 patients.
In all, 876 (69%) of the questionnaires were returned completed. Of these, 574 (65.5%) gave consent for their participation in further research, the team reports in the journal Heart.
Multiple logistic regression analysis revealed that patients were more likely to consent to participation in further research if the factors they had undergone prior percutaneous transluminal coronary angioplasty, a last recorded blood pressure of less than 140/90 mmHg, a last recorded total cholesterol level of less than 5 mmol/l, and were an ex-smoker, as opposed to a current or non-smoker, at respective odds ratios of 1.77, 1.45, 1.71, and 1.73.
The team says: "The implication is that if cohorts in the future are dependent upon prior written consent they are likely to contain disproportionate numbers of those who have made healthy lifestyle decisions, who have previously benefited from healthcare, or those whose clinical risk factors are already well managed.
"This may have two serious consequences: first, the generalizability of observational research will be reduced; second, the effects of treatments may be variously overestimated or underestimated if those who are most unwell or are not making healthy lifestyle decisions are under-represented in study populations."
In an accompanying editorial, Cornelia Junghans and Melvyn Jones, from Royal Free and University College London Medical School in the UK, write: "Possibly, the public may decide that individual privacy is more important than the societal benefits of research, once an open debate has taken place.
"In this case, patient education may be the only way forward to ensure adequate and unbiased participation in research."
Free abstract
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