Exercise Intolerance in Heart Failure With Preserved Ejection Fraction: Arterial Stiffness and Abnormal Left Ventricular Hemodynamic Responses During Exercise

Abstract

BackgroundArterial stiffness is thought to contribute to the pathophysiology of heart failure with preserved ejection fraction (HFpEF). We sought to examine arterial stiffness in HFpEF and hypertension and investigate associations of arterial and left ventricular hemodynamic responses to exercise. Methods and ResultsA total of 385 symptomatic individuals with an EF of ≥50% underwent upright cardiopulmonary exercise testing with invasive hemodynamic assessment of arterial stiffness and load (aortic augmentation pressure, augmentation index, systemic vascular resistance index, total arterial compliance index, effective arterial elastance index, and pulse pressure amplification) at rest and during incremental exercise. An abnormal hemodynamic response to exercise was defined as a steep increase in pulmonary capillary wedge pressure relative to cardiac output (∆PCWP/∆CO > 2 mm Hg/L/min). We compared rest and exercise measures between HFpEF and hypertension in multivariable analyses. Among 188 participants with HFpEF (mean age 61 ± 13 years, 56% women), resting arterial stiffness parameters were worse compared with 94 hypertensive participants (mean age 55 ± 15 years, 52% women); these differences were accentuated during exercise in HFpEF (all P ≤ .0001). Among all participants, exercise measures of arterial stiffness correlated with worse ∆PCWP/∆CO. Specifically, a 1 standard deviation higher exercise augmentation pressure was associated with 2.15-fold greater odds of abnormal LV hemodynamic response (95% confidence interval 1.52–3.05; P < .001). Further, exercise measures of systemic vascular resistance index, elastance index, and pulse pressure amplification correlated with a lower peak oxygen consumption. ConclusionsExercise accentuates the increased arterial stiffness found in HFpEF, which in turn correlates with left ventricular hemodynamic responses. Unfavorable ventricular–vascular interactions during exercise in HFpEF may contribute to exertional intolerance and inform future therapeutic interventions.