Abstract MP65: Masked Hypertension is Associated with Cardiovascular Disease Events in African Americans: The Jackson Heart Study

Abstract

Introduction: Masked hypertension has been associated with increased cardiovascular disease (CVD) risk in Europeans and Asians. Hypothesis: Determine the association of masked hypertension with CVD events and all-cause mortality in African Americans (AA). Methods: The Jackson Heart Study, an exclusively AA population-based, prospective cohort study, was restricted to participants with clinic systolic/diastolic blood pressure (SBP/DBP) < 140/90 mmHg and valid ambulatory blood pressure monitoring (ABPM) at the baseline exam in 2000-2004 (n=738). Masked daytime hypertension was defined as mean ambulatory daytime (10am-8pm) SBP ≥ 135 mmHg or DBP ≥ 85 mmHg. Masked nocturnal hypertension was defined as mean ambulatory nighttime (12am-6am) SBP ≥ 120 mmHg or DBP ≥ 70 mmHg. Using all ABPM measurements, masked 24-hour hypertension was defined as mean SBP ≥ 130 mmHg or DBP ≥ 80 mmHg. CVD events (nonfatal/fatal stroke, nonfatal myocardial infarction or fatal coronary heart disease) and all-cause mortality were identified and adjudicated through December 31, 2011. Results: Any masked hypertension (masked daytime, nocturnal or 24-hour hypertension) was present in 52.2% of participants; 28.2% had masked daytime hypertension, 48.2% had masked nocturnal hypertension and 31.7% had masked 24-hour hypertension. There were 51 CVD events and 44 deaths over a median follow up of 8.2 and 8.5 years, respectively. The CVD rate (95% CI) per 1,000 person years in participants with and without any masked hypertension were 13.5 (9.9-18.4) and 3.9 (2.2-7.1), respectively (Table). The multivariable adjusted hazard ratio (95% CI) between any masked hypertension and CVD was 2.49 (1.26-4.93). CVD rates for those with and without masked daytime, nocturnal and 24-hour hypertension, and the hazard ratios for CVD associated with masked daytime, nocturnal and 24-hour hypertension, were similar. Masked hypertension was not associated with all-cause mortality. Conclusion: Masked hypertension is common and associated with increased CVD risk in AAs.