Statins for Prevention of Cardiovascular Disease in Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force.

IMPORTANCE

Cardiovascular disease (CVD), the leading cause of mortality and morbidity in the United States, may be potentially preventable with statin therapy.

OBJECTIVE

To systematically review benefits and harms of statins for prevention of CVD to inform the US Preventive Services Task Force.

DATA SOURCES

Ovid MEDLINE (from 1946), Cochrane Central Register of Controlled Trials (from 1991), and Cochrane Database of Systematic Reviews (from 2005) to June 2016.

STUDY SELECTION

Randomized clinical trials of statins vs placebo, fixed-dose vs titrated statins, and higher- vs lower-intensity statins in adults without prior cardiovascular events.

DATA EXTRACTION AND SYNTHESIS

One investigator abstracted data, a second checked data for accuracy, and 2 investigators independently assessed study quality using predefined criteria. Data were pooled using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

All-cause mortality, CVD-related morbidity or mortality, and harms.

RESULTS

Nineteen trials (n = 71 344 participants [range, 95-17 802]; mean age, 51-66 years) compared statins vs placebo or no statin. Statin therapy was associated with decreased risk of all-cause mortality (risk ratio [RR], 0.86 [95% CI, 0.80 to 0.93]; I2 = 0%; absolute risk difference [ARD], -0.40% [95% CI, -0.64% to -0.17%]), cardiovascular mortality (RR, 0.69 [95% CI, 0.54 to 0.88]; I2 = 54%; ARD, -0.43% [95% CI, -0.75% to -0.11%]), stroke (RR, 0.71 [95% CI, 0.62 to 0.82]; I2 = 0; ARD, -0.38% [95% CI, -0.53% to -0.23%]), myocardial infarction (RR, 0.64 [95% CI, 0.57 to 0.71]; I2 = 0%; ARD, -0.81% [95% CI, -1.19 to -0.43%]), and composite cardiovascular outcomes (RR, 0.70 [95% CI, 0.63 to 0.78]; I2 = 36%; ARD, -1.39% [95% CI, -1.79 to -0.99%]). Relative benefits appeared consistent in demographic and clinical subgroups, including populations without marked hyperlipidemia (total cholesterol level <200 mg/dL); absolute benefits were higher in subgroups at higher baseline risk. Statins were not associated with increased risk of serious adverse events (RR, 0.99 [95% CI, 0.94 to 1.04]), myalgias (RR, 0.96 [95% CI, 0.79 to 1.16]), or liver-related harms (RR, 1.10 [95% CI, 0.90 to 1.35]). In pooled analysis, statins were not associated with increased risk of diabetes (RR, 1.05 [95% CI, 0.91 to 1.20]), although statistical heterogeneity was present (I2 = 52%), and 1 trial found high-intensity statins associated with increased risk (RR, 1.25 [95% CI, 1.05 to 1.49]). No trial directly compared titrated vs fixed-dose statins, and there were no clear differences based on statin intensity.

CONCLUSIONS AND RELEVANCE

In adults at increased CVD risk but without prior CVD events, statin therapy was associated with reduced risk of all-cause and cardiovascular mortality and CVD events, with greater absolute benefits in patients at greater baseline risk.