ASSOCIATION OF CARDIOVASCULAR ENDPOINTS AND MORTALITY WITH CENTRAL AND PERIPHERAL PULSATILE BLOOD PRESSURE COMPONENTS

Abstract

Objective: Pulsatile blood pressure (pBP) confers cardiovascular risk. Whether associations of cardiovascular endpoints are tighter for central than peripheral systolic or pulse pressure (cSBP, pSBP, cPP, pPP) is uncertain. Design and method: We constructed the International Database of Central Arterial Properties for Risk Stratification (IDCARS), allowing a subject-level meta-analysis. IDCARS cohorts qualified for inclusion in the present analysis, if peripheral and central BP and cardiovascular risk factors had been measured at baseline, and if follow-up included both fatal and non-fatal outcomes. Results: Among 5608 participants (54.1% women; mean age, 54.2 years) enrolled in nine studies, median follow-up was 4.1 years. pSBP and pPP averaged 134.1 and 53.9 mmHg, and cSBP and cPP, estimated tonometrically from the radial waveform, 123.7 and 42.5 mmHg. The primary composite cardiovascular endpoint occurred in 317 participants (5.7%). Across fourths of the cPP distribution, rates increased exponentially (2.9, 5.7, 9.7, and 26.1 per 1000 person-years) with comparable estimates for cSBP, pSBP and pPP. The multivariable-adjusted hazard ratios, expressing the risk per 1-SD increment in blood pressure (HR), were 1.33 (95% confidence interval, 1.19–1.50) for cPP, 1.47 (1.31–1.64) for cSBP, 1.31 (1.17–1.46) for pPP, and 1.45 (1.30–1.62) for pSBP (P < 0.001). Further adjustment of cPP and cSBP, respectively for pPP and pSBP, and vice versa, removed the significance of all HRs. Adding cPP, cSBP, pSBP, pPP to a base model including covariables increased model fit (P < 0.001) with generalised R2 increments ranging from 0.40 to 0.77%, but adding a second pBP to a model including already one did not. Analyses of total mortality (204 deaths) and 106 cerebrovascular endpoints and sensitivity analyses across various subgroups produced consistent results. Conclusions: In this subject-level meta-analysis, the primary endpoint, mortality and cerebrovascular events were similarly associated with central than peripheral pBP.