Around-the-clock Ambulatory Blood Pressure Monitoring is Required to Properly Diagnose Resistant Hypertension and Assess Associated Vascular Risk

Ramón C. Hermida, Diana E. Ayala, María T. Ríos, José R. Fernández, Artemio Mojón, Michael H. Smolensky

Diagnosis of resistant hypertension (RH) is currently based upon awake-time office blood pressure (BP). An increasing number of studies have documented abnormally elevated sleep-time BP in most RH patients, indicating that diagnosis of true RH cannot be determined solely by comparison of office BP with either patient awake-time BP self-measurements or awake-BP mean from ambulatory monitoring (ABPM), as is customary in the published literature. Moreover, the ABPM-determined sleep-time BP mean is an independent and stronger predictor of cardiovascular and cerebrovascular disease (CVD) risk than either daytime office/ABPM-derived awake or 24-hour means. Results of the recently completed MAPEC (Monitorización Ambulatoria para Predicción de Eventos Cardiovasculares) prospective outcomes study, which included a large cohort of RH patients, established that time of treatment relative to circadian rhythms constituted a critically important yet often neglected variable with respect to BP control. The study found that bedtime versus morning ingestion of the full dose of ≥1 BP-lowering medications resulted in both better therapeutic normalization of sleep-time BP and reduced CVD morbidity and mortality, including in RH patients. Accordingly, ABPM is highly recommended to properly diagnose and manage true RH, with a bedtime hypertension medication regimen as the therapeutic scheme of choice.