Association of polypill therapy with cardiovascular outcomes, mortality, and adherence: A systematic review and meta-analysis of randomized controlled trials

Prior studies have reported improvements in population-level risk factor burden and cardiovascular disease (CVD) outcomes using polypills for CVD risk reduction. However, a comprehensive assessment of the impact of polypills on CVD outcomes, mortality, adherence, and side effects across different settings has not previously been reported. We performed a systematic review and meta-analysis of randomized controlled trials examining the association between polypill therapy and CVD outcomes published before February 2021. The primary outcome of interest was the risk of major adverse CVD events (MACE). Risk ratios for dichotomous outcomes were converted to log RR and pooled using a generic inverse variance weighted random-effects model. Data for continuous outcomes were pooled using random-effects modeling and presented as mean differences with 95% CIs. Eight studies representing 25,584 patients were included for analysis. In the overall pooled analysis, the use of polypills was associated with a non-significant reduction in the risk of MACE (RR: 0.85; 95% CI: 0.70-1.02) and significant reductions in the risk of all-cause mortality (RR: 0.90; 95% CI: 0.81-1.00). The reductions in the risk of MACE with polypill use varied by baseline risk and nature of the study population (primary prevention vs. secondary prevention), with the most significant risk reduction among lower-risk cohorts, including within primary prevention populations [RR 0.70 (0.62, 0.79)]. Among measures of CVD risk factors, modest but significant reductions were observed for systolic and diastolic blood pressure [systolic: mean difference 1.99 mmHg (95% CI: -3.07 to -0.91); diastolic: mean difference 1.30 mmHg (95% CI: -2.42 to -0.19), but not for levels of total or low-density lipoprotein-cholesterol. Use of the polypill strategy significantly improved drug adherence (RR: 1.31; 95% CI: 1.11-1.55) with no association between polypill use and rates of adverse events or drug discontinuation. The use of polypill formulations is associated with significant reductions in CVD risk factors and the risk of all-cause mortality and MACE, particularly in the low-risk and primary prevention population.