Background Left ventricular (LV) afterload is composed of systemic vascular resistance (SVR) and components of pulsatile load, including total arterial compliance (TAC), and reflection magnitude (RM). RM, which affects the LV systolic loading sequence, has been shown to strongly predict HF. Effective arterial elastance (Ea) is a commonly used parameter initially proposed to be a lumped index of resistive and pulsatile afterload. We sought to assess how various LV afterload parameters predict heart failure (HF) risk and whether RM predicts HF independently from subclinical atherosclerosis. Methods We studied 4345 MESA participants who underwent radial arterial tonometry and cardiac output (CO) measurements with the use of cardiac MRI. RM was computed as the ratio of the backward (Pb) to forward (Pf) waves. TAC was approximated as the ratio of stroke volume (SV) to central pulse pressure. SVR was computed as mean pressure/CO. Ea was computed as central end-systolic pressure/SV. Results During 10.3 years of follow-up, 91 definite HF events occurred. SVR (P = .74), TAC (P = .81), and Ea (P = .81) were not predictive of HF risk. RM was associated with increased HF risk, even after adjustment for other parameters of arterial load, various confounders, and markers of subclinical atherosclerosis (standardized hazard ratio [HR] 1.49, 95% confidence interval [CI] 1.18–1.88; P = .001). Pb was also associated with an increased risk of HF after adjustment for Pf (standardized HR 1.43, 95% CI 1.17–1.75; P = .001). Conclusions RM is an important independent predictor of HF risk, whereas TAC, SVR, and Ea are not. Our findings support the importance of the systolic LV loading sequence on HF risk, independently from subclinical atherosclerosis.
Bibliographical noteFunding Information:
Dr Chirinos has received consulting fees from OPKO Healthcare, Bristol-Myers Squibb, Merck, Microsoft Research, and Fukuda Denshi, receives research funding from the National Institutes of Health, Veterans Affairs Administration, American College of Radiology Network, Bristol-Myers Squibb, and Fukuda Denshi, and is named as inventor in a University of Pennsylvania patent application for the use of inorganic nitrate/nitrite for HFpEF. The other authors report no potential conflicts of interest.
- Wave reflections
- heart failure
- vascular resistance