Combined ventricular systolic and arterial stiffening in patients with heart failure and preserved ejection fraction: Implications for systolic and diastolic reserve limitations

Abstract

Background - Heart failure with preserved ejection fraction (HF-nlEF) is common in aged individuals with systolic hypertension and is frequently ascribed to diastolic dysfunction. We hypothesized that such patients also display combined ventricular-systolic and arterial stiffening that can exacerbate blood pressure lability and diastolic dysfunction under stress. Methods and Results - Left ventricular pressure-volume relations were measured in patients with HF-nlEF (n=10) and contrasted with asymptomatic age-matched (n=9) and young (n=14) normotensives and age- and blood pressure-matched controls (n=25). End-systolic elastance (stiffness) was higher in patients with HF-nlEF (4.7±1.5 mm Hg/mL) than in controls (2.1±0.9 mm Hg/mL for normotensives and 3.3±1.0 mm Hg/mL for hypertensives; P<0.001). Effective arterial elastance was also higher (2.6±0.5 versus 1.9±0.5 mm Hg/mL) due to reduced total arterial compliance; the latter inversely correlated with end-systolic elastance (P=0.0001). Body size and stroke volumes were similar and could not explain differences in ventricular-arterial stiffening. HF-nlEF patients also displayed diastolic abnormalities, including higher left ventricular end-diastolic pressures (24.3±4.6 versus 12.9±5.5 mm Hg), caused by an upward-shifted diastolic pressure-volume curve. However, isovolumic relaxation and the early-to-late filling ratio were similar in age- and blood pressure-matched controls. Ventricular-arterial stiffening amplified stress-induced hypertension, which worsened diastolic function, and predicted higher cardiac energy costs to provide reserve output. Conclusion - Patients with HF-lnEF have systolic-ventricular and arterial stiffening beyond that associated with aging and/or hypertension. This may play an important pathophysiological role by exacerbating systemic load interaction with diastolic function, augmenting blood pressure lability, and elevating cardiac metabolic demand under stress.