Triglyceride-lowering therapies reduce cardiovascular disease event risk in subjects with hypertriglyceridemia

Cardiovascular outcomes trials of fibrates, niacin, or omega-3 fatty acids alone, or added to a statin, have not consistently demonstrated reduced risk, but larger, statistically significant clinical benefits have been reported in subgroups with elevated triglycerides (TG) and/or elevated TG plus low high-density lipoprotein cholesterol (HDL-C).

To perform a meta-analysis of the effects of therapies targeting TG and TG-rich lipoprotein cholesterol on cardiovascular disease event risk in subjects with elevated TG or elevated TG paired with low HDL-C.

Publications were identified using PubMed, the Cochrane Central Register of Controlled Trials, clinicaltrials.gov, the World Health Organization International Clinical Trials Registry Platform, and Internet Stroke Center. Random-effects meta-analysis models were used to generate summary relative risk estimates and 95% confidence intervals. Heterogeneity was assessed by χ(2) and I(2) statistics, and the impact of each trial was assessed in one study-removed sensitivity analyses.

Six trials of fibrates, 2 of niacin, 1 of fibrate + niacin, and 1 of omega-3 eicosapentaenoic acid ethyl esters were identified. For the prespecified primary cardiovascular disease or coronary heart disease end point used in each trial, the summary relative risk estimate (95% confidence interval) for subjects with elevated TG was 0.82 (0.73-0.91), p-heterogeneity = 0.13, I(2) = 36.2, and for subjects with elevated TG and low-HDL-C, it was 0.71 (0.63-0.81), p-heterogeneity = 0.52, I(2) = 0.0. There was no evidence of publication bias, and the results remained statistically significant when each individual trial was removed.

Drugs that substantially, but not exclusively, lower TG and TG-rich lipoprotein cholesterol may have cardiovascular benefits in individuals with elevated TG, particularly if accompanied by low HDL-C.