Association of Variability and Hypertensive Loads in 24-h Blood Pressure with Mortality and Cardiovascular Risk

Abstract Background Evidence shows that high 24-h blood pressure (BP) variability increases cardiovascular risk. We investigated whether 24-h BP variability relates to mortality and cardiovascular risk due to inherent variability and/or hypertensive loads in 24-h BP. Methods A total of 1050 participants from the Maracaibo Aging Study (mean age, 66y; women, 67.2%) underwent 24-h ambulatory BP monitoring and were followed between 2001-2016. To evaluate inherent BP variability, we used average real variability (ARV) as it captures variability among consecutive BP readings. 24-h systolic BP load was the proportion (%) of systolic BP readings ≥130 mmHg during the daytime and ≥110 during the nighttime. Our primary endpoint was total mortality and major adverse cardiovascular endpoints (MACE). Statistics included Cox proportional models. Results During a median follow-up of 8.3 years, 299 participants died and 210 experienced MACE. Each +2 mmHg (corresponding to 1-standard deviation) higher 24-h systolic ARV (mean value, 9.0±2.0 mmHg) was associated with higher hazard ratios (HR) for mortality by 1.28-fold (95% confidence interval [CI], 1.14-1.43) and for MACE by 1.24-fold (95% CI, 1.081.42). Each 30% higher 24-h systolic BP loads (median value, 63%) was associated with mortality and MACE with HRs of 1.29 (95% CI, 1.15-1.46) and 1.28 (95% CI, 1.101.48); respectively. After models were additionally adjusted by BP level, only ARV was associated with mortality (HR, 1.17; 95% CI, 1.04-1.33) and MACE (HR, 1.16; 95% CI, 1.00-1.34). Conclusions High ARV and hypertensive loads in 24-h systolic BP were associated with mortality and cardiovascular risk, however only ARV is associated independently of the BP level.