Cardiovascular endpoints in relation to the central arterial pressure-time indexes

Multiple articles focused on the central arterial systolic (SPTI) and diastolic (DPTI) pressure-time indexes and the subendocardial viability ratio (SEVR). However, whether these indexes contribute to risk stratification in the general population is unknown. SPTI, DPTI and SEVR were noninvasively measured by the SphygmoCor technology. Incidence rates and standardized (per 1-SD increment) multivariable-adjusted hazard ratios (HRs) for cardiovascular (primary) and cardiac endpoints and stroke were evaluated in the International Database of Central Arterial Properties for Risk Stratification (n = 5099). Model refinement was assessed by the area under the curve (AUC) and the integrated discrimination (IDI) and net reclassification (NRI) improvement. Over 4 years (median), 215 cardiovascular, 133 cardiac endpoints and 79 strokes occurred. For SPTI, fully adjusted HRs were 1.37 (95% CI: 1.18-1.59), 1.35 (1.11-1.64) and 1.33 (1.05-1.69) for the cardiovascular and cardiac endpoints and stroke. The corresponding HRs for DPTI were 1.49 (1.31-1.69), 1.23 (1.02-1.48) and 1.74 (1.46-2.07). For SEVR, none of the HRs reached significance. Analyses with these indexes categorized by quartiles were confirmatory. Analyses stratified by various risk factors did not reveal subgroup differences. For the cardiovascular endpoint, adding SPTI or DPTI to the base model improved the AUC, while adding SPTI or DPTI combined with mean arterial pressure, increased IDI by ~1.7% and NRI by ~17% (P < 0.001 for all). Whereas cardiovascular and cardiac endpoints and stroke were related with the non-invasively measured SPTI and DPTI, SEVR was not.