Do antihypertensive drugs combinations in single-pill combination improve cardiovascular outcomes?

Recommendations and guidelines propose to combine antihypertensive drugs to improve BP control, highlighting the advantages of single-pill combinations (SPCs) to improve treatment adherence. It is speculated that, compared with free-dose combinations (Free-DCs), SPC should achieve a reduction in cardiovascular (CV) events and mortality through better adherence and BP control. However, there is little information in this regard. For this reason, the objective of this review was to provide a descriptive analysis the differences in CV outcomes between SPCs antihypertensive drugs treatments vs. Free-DCs treatments. Ten studies were found and none had a randomized controlled design. Medication adherence was higher with SPCs, but outcomes were not adjusted for the adherence / persistence. When groups were compared according to similar adherence degrees, the statistical significance in favor of SPCs disappeared. Thus, randomized controlled studies are necessary to evaluate if SPCs have any effect beyond the improvement of the adherence to hypertensive treatment.