Predictors and mediators of successful long-term withdrawal from antihypertensive medications

Background: National guidelines recommend consideration of step down or wit hdrawal of medication in patients with well-controlled hypertension, but kn owledge of factors that predict or mediate success in achieving this goal i s limited. Objective: To identify patient characteristics associated with success, in controlling blood pressure (BP) after withdrawal of antihypertensive medica tion. Design: The Trial of Nonpharmacologic Interventions in the Elderly tested w hether lifestyle interventions designed to promote weight loss or a reduced intake of sodium, alone or in combination, provided satisfactory BP contro l among elderly patients (aged 60-80 years) with hypertension after withdra wal from antihypertensive drug therapy. Participants were observed for 15 t o 36 months after attempted drug withdrawal. Main Outcome Measures: Trial end points were defined by (1) a sustained BP of 150/90 mm Hg or higher, (2) a clinical cardiovascular event, or (3),a de cision by participants or their personal physicians to resume BP medication . Results: Proportional hazards regression analyses indicated that the hazard (+/-SE) of experiencing an end point among persons assigned to active inte rventions wa 75% +/- 9% (weight loss); 68% +/- 7% (sodium reduction), and 5 5% +/- 7% (combined weight loss/sodium reduction) that of the hazard for th ose assigned to usual care. Lower baseline systolic BP (P<.001), fewer year s since diagnosis of hypertension (P<.001), fewer years of antihypertensive treatment (P<.001), and no history of cardiovascular disease(P=.01) were i mportant predictors of maintaining successful nonpharmacological BP control throughout follow-up, based on logistic regression analysis. Age, ethnicit y, baseline level of physical activity, baseline weight, medication class, smoking status, and alcohol intake were not statistically significant predi ctors. During follow-up, the extent of weight loss (P =.001) and urinary so dium excretion (P =.04) were associated with a reduction in the risk of tri al end points in a graded fashion. Conclusions: Withdrawal from antihypertensive medication is most likely to be successful in patients with well- controlled hypertension who have been recently (within 5 years) diagnosed or treated, and who adhere to lifestyle interventions involving weight loss and sodium reduction. More than 80% of these patients may have suer cess in medication withdrawal for longer than 1 year.