Relative prognostic importance of aortic and brachial blood pressures for cardiovascular and mortality outcomes in patients with resistant hypertension and diabetes: a two cohorts prospective study

Abstract

Objective: The prognostic importance of derived central/aortic blood pressures (BPs) in relation to brachial office and ambulatory BPs has never been investigated in patients with resistant hypertension (RHT) or type 2 diabetes (T2D). We aimed to evaluate it in two cohorts with 532 individuals with RHT and 467 with T2D (median follow-ups 4.4 and 7.3 years, respectively). Methods: Central/aortic pressure waveforms were estimated by radial tonometry by a type 1 device (SphygmoCor device/software), and other parameters of central hemodynamics (augmentation index and Buckberg indices) were calculated. Multivariate Cox regressions examined the associations between central and peripheral BPs with cardiovascular events incidence and mortality, and C-statistics and the integrated discrimination improvement index evaluated the improvement in risk discrimination. Results: During follow-up, there were 52 cardiovascular events and 51 all-cause deaths in the RHT and 104 and 137 in the T2D cohort. No aortic BP was better than its brachial counterpart in predicting risk or improving discrimination for any outcome in either cohort. In the RHT cohort, ambulatory BPs were superior to central and office-brachial BPs. Otherwise, the augmentation index in RHT (hazard ratios: 1.5, for 1-SD increment) and the Buckberg index in T2D (hazard ratios: 0.7–0.8) were independent predictors of cardiovascular/mortality outcomes, and improved risk discrimination (integrated discrimination improvement up to 25% in RHT and 15% in T2D). Conclusion: Derived aortic BPs by a type 1 device did not improve cardiovascular/mortality risk prediction over brachial BPs in our cohorts of patients with RHT and T2D, but additional parameters of central hemodynamics may be useful.