RESUMO
BACKGROUND: Niacin or nicotinic acid (vitamin B3) raises the levels of high-density lipoprotein cholesterol (HDL) by about 30% to 35%. In patients with prior coronary disease, 7 trials have been published on clinical cardiovascular disease outcomes and the results, not surprisingly, are inconsistent. Hence, we performed this meta-analysis of randomized placebo-controlled trials (RCTs) to evaluate the effect of niacin on cardiovascular outcomes in patients with coronary artery disease. METHODS: A systematic search using PubMed, EMBASE, and Cochrane library databases was performed. Seven studies with a total of 5137 patients met our inclusion criteria. Heterogeneity of the studies was analyzed by the Cochran Q statistics. The significance of common treatment effect was assessed by computing the combined relative risks using the Mantel-Haenszel fixed-effect model. A 2-sided alpha error of less than .05 was considered statistically significant (P < .05). RESULTS: Compared to placebo group, niacin therapy significantly reduced coronary artery revascularization (RR [relative risk]: 0.307 with 95% CI: 0.150-0.628; P = .001), nonfatal myocardial infarction ([MI]; RR: 0.719; 95% CI: 0.603-0.856; P = .000), stroke, and TIA ([transient ischemic attack] RR: 0.759; 95%CI: 0.613-0.940; P = .012), as well as a possible but nonsignificant decrease in cardiac mortality (RR: 0.883: 95% CI: 0.773-1.008; p= 0.066). CONCLUSIONS: In a meta-analysis of seven trials of secondary prevention, niacin was associated with a significant reduction in cardiovascular events and possible small but non-significant decreases in coronary and cardiovascular mortality.
