Effectiveness of polypill for primary and secondary prevention of cardiovascular disease: a pragmatic cluster-randomised controlled trial (PolyPars).

Background: We aimed to investigate the effectiveness of fixed-dose combination therapy (polypill) for primary and secondary prevention of major cardiovascular diseases in a typical rural setting.

Methods: The PolyPars Study is a two-arm pragmatic cluster-randomised trial nested within the PARS cohort study, including all residents aged over 50 years in the entire district in southern Iran. The 91 villages underwent random allocation into two arms: the control arm, encompassing 45 clusters, was subjected to non-pharmacological intervention (educational training on healthy lifestyle), whereas the intervention arm, comprising 46 clusters, received the non-pharmacological interventions in conjunction with a once-daily polypill tablet. This tablet comprised two antihypertensive agents, a statin and aspirin. The primary outcome was the first occurrence of major cardiovascular events defined as a composite of hospitalisation for acute coronary syndrome (non-fatal myocardial infarction and unstable angina), fatal myocardial infarction, non-fatal and fatal stroke, sudden death and heart failure. The Cox regression model, with shared frailty, was used to account for clustering effect.

Results: During December 2015-December 2016, a total of 4415 participants aged 50-75 years were recruited (2200 participants in the intervention arm and 2215 participants in the control arm). The overall median of follow-up duration was 4.6 years (interquartile interval 4.4-4.9). The achieved adherence rate to polypill in intervention arm was 86%. In the control group, 176 (8.0%) of 2215 participants developed primary outcome, compared with 88 (4.0%) of 2200 participants in the polypill group. We found substantial reduction in risk of primary outcome both in relative and absolute scales (HR 0.50, 95% CI 0.38 to 0.65; absolute risk reduction 4.0%, 95% CI 2.5% to 5.3%). No difference in serious adverse events was observed between the two groups.

Conclusions: The fixed-dose combination therapy using polypill can safely halve the risk of major cardiovascular diseases at the population level.

Trial registration number: NCT03459560.