Primary prevention of cardiovascular diseases with statin therapy: a meta-analysis of randomized controlled trials

Primary prevention of cardiovascular diseases with statin therapy: a meta-analysis of randomized controlled trials

Thavendiranthan et al have undertaken a study to examine the role of statins in primary prevention of cardiovascular disease (1)

Cochrane Collaboration, and American College of Physicians Journal Club databases were searched for RCTs published between 1966 and June 2005. The authors included RCTs with follow-up of 1 year or longer, more than 100 major CV events, and 80% or more of the population without CV disease. From each trial, demographic data, lipid profile, CV outcomes, mortality, and adverse outcomes were recorded. Summary relative risk (RR) ratios with 95% confidence intervals (CIs) were calculated using a random effects model

seven trials with 42,848 patients were included. Note that the analysis also included primary prevention patients from the HPS trial (more than 80% were in secondary prevention) and the patients from the CARDS trial

mean follow-up was 4.3 years

statin therapy reduced the RR of major coronary events, major cerebrovascular events, and revascularizations by 29.2% (95% CI, 16.7%-39.8%) (P<.001), 14.4% (95% CI, 2.8%-24.6%) (P = 0.02), and 33.8% (95% CI, 19.6%-45.5%) (P<.001), respectively

statins produced a nonsignificant 22.6% RR reduction in coronary heart disease mortality (95% CI, 0.56-1.08) (P = 0.13)

no significant reduction in overall mortality (RR, 0.92 [95% CI, 0.84-1.01]) (P = .09) or increases in cancer or levels of liver enzymes or creatine kinase were observed

the authors affirm that statin therapy could reduce the absolute risk of coronary events during the next 4.3 years by 0.75% in low-risk patients (NNT= 133), by 1.63% (NNT=61) in moderate-risk patients and by 2.51% (NNT=40) in high-risk patients. They also conclude that it could be cost-effective in patients with an absolute risk over 20% of having a coronary event in the following 10 years. It would not be cost-effective in patients with a risk <10%, and its use would be controversial in the risk-group of 10-20%

the study authors concluded that, in patients without CV disease, statin therapy decreases the incidence of major coronary and cerebrovascular events and revascularizations but not coronary heart disease or overall mortality

Reference:

1. Thavendiranathan P et al. Primary prevention of cardiovascular diseases with statin therapy: a meta-analysis of randomized controlled trials. Arch Intern Med. 2006 Nov 27;166(21):2307-13.