The prognostic value of nocturnal blood pressure (BP) reduction in resistant hypertension (RH) is unknown. The objective of this prospective study was to evaluate its importance as a predictor of cardiovascular morbidity and mortality.
At baseline, 556 patients with RH underwent clinical and laboratory examinations and 24-hour ambulatory BP monitoring. The primary end points were a composite of fatal or nonfatal cardiovascular events, all-cause mortality, and cardiovascular mortality. Multiple Cox regression was used to assess associations between the nocturnal BP reduction and the subsequent end points.
After a mean follow-up of 4.8 years (range, 1-103 months), 109 patients (19.6%) reached the composite end point, with 70 all-cause and 46 cardiovascular deaths. A nondipping pattern was present in 360 patients (65.0%). After adjustment for age, sex, body mass index, diabetes, smoking status, physical inactivity, dyslipidemia, previous cardiovascular disease, number of antihypertensive drugs in use, and office and 24-hour ambulatory BP readings, the nondipping pattern was an independent predictor of the composite end point (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.12-2.71) and of cardiovascular mortality (HR, 2.31; 95% CI, 1.09-4.92). In subgroup analysis, the reduced (HR, 1.71; 95% CI, 1.03-2.83) and reverted (HR, 1.89; 95% CI, 1.04-3.43) dipping patterns were predictive of total cardiovascular events. The effect of the nondipping pattern on cardiovascular prognosis was stronger in younger patients and in those with true RH.
The nocturnal BP variability patterns provide valuable prognostic information for stratification of cardiovascular morbidity and mortality risk in patients with RH, above and beyond other traditional cardiovascular risk factors and mean ambulatory BP levels.