EXERCISE CAPACITY AND CENTRAL ARTERIAL HEMODYNAMICS IN HEART FAILURE WITH PRESERVED EJECTION FRACTION

Natalie J. Bohmke1, Domenico A. Chavez1, Hayley E. Billingsley1, Michele Golino1, Sebastian Pinel1, Roshanak Markley1, Antonio Abbate2, Salvatore Carbone1, Danielle L. Kirkman1. 1Virginia Commonwealth University, Richmond, VA. 2University of Virginia, Charlottesville, VA. BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is characterized by exertional intolerance. Magnified arterial wave reflections that increase the left ventricular (LV) late systolic pulsatile load may contribute to HFpEF related exercise intolerance. Our aim was to investigate the relationship between resting aortic hemodynamics and exercise capacity. METHODS: 35 patients with HFpEF (24 female, 27 African American; Median [IQR]: Age 63 [54, 69] years; BMI 37.9 [33.4, 40.9] kg/m2) underwent vascular testing and cardiopulmonary exercise testing. Peak oxygen consumption (VO2 peak) was measured via breath-by-breath gas analysis during a 0.6 MET•min-1 graded treadmill test to volitional fatigue. Resting aortic pressure waveforms were synthesized from radial artery waveforms obtained by applanation tonometry. Specifically, we report the augmentation index normalized to a heart rate of 75bpm (AIx75): an indicator of arterial stiffness and surrogate for the magnitude of the LV systolic load; the round-trip transit time (Tr): the travel time of the pressure wave from the heart to the major reflecting sites and back; and the reflection index (RIx): the magnitude of reflected wave relative to the forward travelling wave. We compared exercise capacity according to a median split for AIx75 (\u3c25\u3e), Tr (\u3c137s\u3e) and RIx (\u3c73\u3e). RESULTS: Patients with a higher AIx75, signifying increased arterial stiffness and increased LV systolic load, had a lower absolute VO2peak (1.28 [1.17, 1.40] vs. 1.85 [1.50, 2.21] L/min, p\u3c0.001) and shorter exercise time (505 [384, 545] vs. 637 [458, 765] seconds, p=0.041). Patients with a faster Tr signifying reflected waves that arrive at the heart earlier in systole, had lower relative VO2peak (13.1 [11.57, 14.6] vs. 17.1 [13.1, 18.6] mL/kg/min, p=0.044) and a trend for shorter exercise times (466 [354, 550] vs. 637 [503, 658] seconds, p=0.056). Patients with higher RIx had a lower absolute VO2peak (1.28 [1.17, 1.66] vs. 1.66 [1.37, 2.12] L/min, p=0.009). CONCLUSIONS: Our results show that in a cohort of patients with HFpEF, aberrant resting arterial hemodynamics that increase LV systolic afterload are associated with worse exercise capacity. Future research should investigate arterial hemodynamics during exercise to provide insight into their potential contribution to exercise intolerance in HFpEF. Supported by AHA 19CDA3474002 & 19CDA34660318 and NIH UL1TR00264