Discontinuation of anti-hypertensive drugs increases 11-year cardiovascular mortality risk in community-dwelling elderly (the Bambuí Cohort Study of Ageing)

BACKGROUND Hypertension remains a major public health problem whose management is hampered by poor persistence with pharmacological therapy. The aim of this study was to evaluate the association between discontinuing antihypertensive drugs (AHDs) and the risk of cardiovascular mortality in the elderly. METHODS A population-based prospective cohort study of all of the ≥ 60-year-old residents in Bambuí city (Brazil) enrolled 1606 subjects (92.2%), of whom 1494 (93.0%) were included in this study. The use of AHDs was ascertained annually in a real-clinical context, and time-varying AHD exposure was categorised as non-use, current use or stopped. The predicted cardiovascular mortality rates were estimated using interval Poisson models for ungrouped person-time data, taking into account current levels of systolic blood pressure (BP). RESULTS The overall adjusted cardiovascular mortality risk ratio of AHD stoppers vs current users was 3.12 (95% CI: 2.35-4.15). There was a significant interaction with BP levels: the association between discontinuing AHDs and the risk of cardiovascular mortality was stronger at higher systolic BP levels. The estimates of the risk of cardiovascular mortality over the follow-up period were similar in AHD users and non-users, for whom AHDs were never prescribed. CONCLUSION Discontinuing AHDs increases the risk of cardiovascular mortality in the elderly. Misconceptions about symptoms or drug-related adverse effects could underlie a subject's decision to discontinue AHDs. Greater attention should be paid to the choice of AHDs and informative action.