Lowering Blood Pressure Improves Diastolic Function, Regardless of Regimen

Lowering Blood Pressure Improves Diastolic Function, Regardless of Regimen

Reductions in blood pressure lead to improved diastolic function — regardless of the antihypertensive drugs used — reports a study in Lancet.

Researchers sought to determine whether the angiotensin-receptor blocker valsartan would be more effective than other antihypertensives at improving diastolic function. They randomized nearly 400 patients with hypertension and evidence of diastolic dysfunction to receive either the ARB or placebo. The patients also received other classes of antihypertensive agents to lower blood pressure to below 135/80 mm Hg.

After 38 weeks, tissue Doppler imaging showed improved diastolic function in both valsartan and placebo recipients, but there was no significant difference between the groups.

Authors of an accompanying commentary note that valsartan might have an advantage in patients with more advanced left ventricular remodeling. Nevertheless, they add, "the good news is that lowering blood pressure improves diastolic function, irrespective of the antihypertensive regimen used."

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ABSTRACT

The Lancet 2007; 369:2079-2087

Articles

Effect of angiotensin receptor blockade and antihypertensive drugs on diastolic function in patients with hypertension and diastolic dysfunction: a randomised trial
Dr Scott D SolomonMD, et al

Summary

Background

Diastolic dysfunction might represent an important pathophysiological intermediate between hypertension and heart failure. Our aim was to determine whether inhibitors of the renin-angiotensin-aldosterone system, which can reduce ventricular hypertrophy and myocardial fibrosis, can improve diastolic function to a greater extent than can other antihypertensive agents.

Methods

Patients with hypertension and evidence of diastolic dysfunction were randomly assigned to receive either the angiotensin receptor blocker valsartan (titrated to 320 mg once daily) or matched placebo. Patients in both groups also received concomitant antihypertensive agents that did not inhibit the renin-angiotensin system to reach targets of under 135 mm Hg systolic blood pressure and under 80 mm Hg diastolic blood pressure. The primary endpoint was change in diastolic relaxation velocity between baseline and 38 weeks as determined by tissue doppler imaging. Analyses were done by intention to treat.

Findings

186 patients were randomly assigned to receive valsartan; 198 were randomly assigned to receive placebo. 43 patients were lost to follow-up or discontinued the assigned intervention. Over 38 weeks, there was a 12·8 (SD 17·2)/7·1 (9·9) mm Hg reduction in blood pressure in the valsartan group and a 9·7 (17·0)/5·5 (10·2) mm Hg reduction in the placebo group. The difference in blood pressure reduction between the two groups was not significant. Diastolic relaxation velocity increased by 0·60 (SD 1·4) cm/s from baseline in the valsartan group (p<0·0001) and 0·44 (1·4) cm/s from baseline in the placebo group (p<0·0001) by week 38. However, there was no significant difference in the change in diastolic relaxation velocity between the groups (p=0·29).

Interpretation

Lowering blood pressure improves diastolic function irrespective of the type of antihypertensive agent used.

Echocardiography Helps Identify Heart Disease

Echocardiography Helps Identify Heart Disease


Test is more accurate than others when used in patients at risk, experts say

By Steven ReinbergHealthDay Reporter

FRIDAY, June 15 (HealthDay News) -- New uses of echocardiography to identify and stratify people with heart disease were highlighted Friday during the American Society of Echocardiography's annual meeting.

"Echocardiography has been around a long time, and it is part of the routine evaluation of heart disease," said Dr. Thomas Ryan, director of the Duke University Heart Center and the society's incoming president. "There has been a lot of technical developments and improvements over the last several years."

Echocardiography, which is basically ultrasound for the heart, is a very accurate and versatile test, Ryan noted. "It can be applied in a lot of different clinical situations," he said. "There is a new population that it is being applied to. It's useful in patients with symptoms, it's useful in patients with a high likelihood of having heart disease, and it is useful for defining the location and extent of heart disease."

In the first presentation, Dr. Farooq A. Chaudhry, director of echocardiography and associate chief of cardiology at St. Luke's-Roosevelt Hospital Center in New York City, and colleagues used stress echocardiography in 447 women to identify their risk for heart disease.

"To identify women at risk for heart disease, we used stress echocardiography, which is done at rest and then during stress," Chaudhry said. "Using this technique, you can differentiate high-risk women from others. If you have an abnormal echo-study, you are three times more likely to have a heart attack or die from heart-related causes."

Chaudhry thinks this technique is more accurate than other methods for identifying heart problems, especially in women. It is a good way to evaluate women who have risk factors for heart disease, he said.

"If women have a history of heart disease, high cholesterol, obesity or diabetes or high blood pressure, this technique should be used to risk stratify them," Chaudhry said.

In another study, Dr. Saritha Dodla and colleagues from the University of Nebraska Medical Center in Omaha found that by using echocardiography, they were able to identify diabetics who were at risk for heart disease even though they had no symptoms.

In the study, the researchers looked at 149 diabetic patients and followed them for an average of almost two years. They found that 25 of the patients had abnormalities in their cardiac arteries. Of these patients, 67 percent were alive after two years, compared with 72 percent of the normal patients.

By looking at heart abnormalities, doctors may be able to diagnose and treat more diabetes patients with blockages of the heart arteries, the researchers concluded.

In a third study, Dr. Jared J. Wyrick of Oregon Health & Science University, and colleagues found that by using echocardiography along with a contrast agent that makes abnormalities easier to see, they were able to identify patients who may be having a heart attack, compared to patients with low-risk chest pain.

In the study, researchers used myocardial contrast echocardiography to evaluate 957 patients complaining of chest pain. They found that by using myocardial contrast echocardiography, 55 percent of the patients could be discharged from the emergency department, thus avoiding admittance charges and follow-up tests. These patients could have saved about $700, plus the inconvenience of hospital stays, the researchers reported.

In the final presentation, Dr. John Postley of Columbia University and colleagues found that by using Screening Vascular Ultrasound, a type of echocardiography, they could identify patients with potential heart disease before symptoms appeared.

In the study, Postley's team used the technique to evaluate 398 patients, ages 33 to 79. The researchers found that 171 patients had plaque build-up in the arteries of the neck and thigh. Of these, 25 percent of men and 35 percent of women were at risk for heart disease.

"These findings suggest that even patients with low Framingham Risk Scores may have cardiovascular disease, as demonstrated by the presence of plaque build-up, and that Screening Vascular Ultrasound is an effective method to identify these patients," Postley said in a prepared statement. "This combination of technologies is wonderful news for the medical community, as it will help identify people with clogged arteries before they even begin showing symptoms, allowing physicians to be more proactive in treatment," he said.

The American Society of Echocardiography's annual meeting is taking place in Seattle.

More information

For more information on echocardiography, visit the American Heart Association.

SOURCES: Thomas Ryan, M.D., director, Duke Heart Center, Duke University, Durham, N.C., incoming president, American Society of Echocardiography; Farooq A. Chaudhry, M.D., director, echocardiography, associate chief of cardiology, St. Luke's-Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York City; June 15, 2007, presentations, 18th annual scientific sessions of the American Society of Echocardiography, Seattle

Stress echo identifies women at highest risk for CAD

Stress echo identifies women at highest risk for CAD

Seattle, Washington - Women who are already at high risk of coronary artery disease can be further stratified into low- and high-risk groups by the use of stress echo, a new study shows [1]. Senior author Dr Farooq A Chaudry (St Luke's-Roosevelt Hospital Center, New York) is to present the findings at the American Society of Echocardiography Scientific Sessions this weekend.

"We took women who were high risk based on clinical factors—such as a family history of CAD, diabetes, or prior MI—and found that those with an abnormal stress echo had a three-times-higher subsequent risk of MI and death than those who recorded a normal stress echo," Chaudry told heartwire.

Chaudry says stress echo—where echocardiography is performed immediately before and immediately after an exercise or pharmacological stress test—is "much more specific" than a 12-lead ECG. It also has advantages over nuclear imaging, another technique commonly employed by echocardiographers, he says.


Women with CAD have atypical presentation

One in three deaths in the US in women is caused by heart disease, compared with one in 30 due to breast cancer, Chaudry explained. However, women with CAD often have atypical presentation, making it difficult to see any problems clearly on ECG.

He and his team evaluated 447 women (mean age 65 years) with a high possibility of CAD—either they had had a prior event or intervention or were deemed to have a pretest likelihood of >85%—who were referred for stress echo (77% with dobutamine).

An abnormal stress echo was defined as one showing either scar or stress-induced ischemia. Follow-up for confirmed MI and death (n=44) was for a mean of 2.6 years.

Among the 447 women, 207 (47%) had an abnormal stress echo, and they had an event rate of 6.1% per year vs 1.8% per year in women with a normal stress echo.


Stress echo: More specific than nuclear testing

Chaudry says stress echo has a number of advantages over nuclear imaging. It is safer for women of reproductive age and no IV is required if conducting an exercise stress test (unless visualization is difficult, in which case an ultrasound image-enhancing agent is used, which needs to be injected into a vein).

Stress echo is also more specific than nuclear testing in that it can pinpoint the exact area of ischemia, he notes. And other anatomical and valvular abnormalities can be seen that are not picked up with nuclear testing. However, nuclear testing is more sensitive, he acknowledged.

He said that institutions tend to favor one technology over the other, often depending on whether they have a strong nuclear lab on site. Nuclear testing is popular in the US because reimbursement is better than for stress echo, he said. "In my institution, we perform about 4000 stress echoes a year and 1500 nuclear tests."

Source:

Bangalore S, Aziz E, Uretsky S, et al. Risk stratification and prognosis of high-risk females undergoing stress echocardiography. American Society of Echocardiography 18th Annual Scientific Sessions; June 16-20, 2007; Seattle, Washington. Presentation P1-20. Available here.