Predictors and mediators of successful long-term withdrawal from antihypertensive medications. TONE Cooperative Research Group. Trial of Nonpharmacologic Interventions in the Elderly.

BACKGROUND: National guidelines recommend consideration of step down or withdrawal of medication in patients with well-controlled hypertension, but knowledge of factors that predict or mediate success in achieving this goal is limited. OBJECTIVE: To identify patient characteristics associated with success in controlling blood pressure (BP) after withdrawal of antihypertensive medication. DESIGN: The Trial of Nonpharmacologic Interventions in the Elderly tested whether lifestyle interventions designed to promote weight loss or a reduced intake of sodium, alone or in combination, provided satisfactory BP control among elderly patients (aged 60-80 years) with hypertension after withdrawal from antihypertensive drug therapy. Participants were observed for 15 to 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 decision 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 interventions was 75% +/- 9% (weight loss), 68% +/- 7% (sodium reduction), and 55% +/- 7% (combined weight loss/sodium reduction) that of the hazard for those assigned to usual care. Lower baseline systolic BP (P < .001), fewer years since diagnosis of hypertension (P < .001), fewer years of antihypertensive treatment (P < .001), and no history of cardiovascular disease (P = .01) were important predictors of maintaining successful nonpharmacological BP control throughout follow-up, based on logistic regression analysis. Age, ethnicity, baseline level of physical activity baseline weight, medication class, smoking status, and alcohol intake were not statistically significant predictors. During follow-up, the extent of weight loss (P = .001) and urinary sodium excretion (P = .04) were associated with a reduction in the risk of trial 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 life-style interventions involving weight loss and sodium reduction. More than 80% of these patients may have success in medication withdrawal for longer than 1 year.