Pulsatile Hemodynamics Are Associated With Exercise Capacity in Patients With Exertional Dyspnea and Preserved Left Ventricular Ejection Fraction.

Abstract

Pulsatile hemodynamics are associated with left ventricular filling pressures and diastolic dysfunction. We investigated their relationship with maximum workload and peak oxygen uptake (peak VO2) in patients with exertional dyspnea and preserved left ventricular ejection fraction (LVEF). Radial waveforms from tonometry were processed with a transfer function, pulse wave analysis and wave separation analysis, yielding central aortic pressures and measures of forward (amplitude of forward wave-Pf) and reflected waves (augmentation index-AIx, augmentation pressure-AP, amplitude of backward wave-Pb) and their ratio (reflection magnitude). Aortic pulse wave velocity (aoPWV) was estimated with a validated formula from single-point waveforms. Ergospirometry for assessment of exercise capacity was performed on a bicycle ergometer, using a ramp protocol. Sixty-six patients were included (43 females; mean age 66 years; 83% hypertensives; mean body mass index 28.3 kg/m2). Mean peak VO2 was 17.0 ml/min/kg, mean achieved maximum workload 104.5 watts (80.9% of a reference population). Maximum workload and peak VO2 showed significant inverse relationships with AIx, AP, Pb, and aoPWV (r = -0.26 to -0.57). In multiple adjusted regression models, brachial and aortic pulse pressure, AP, Pf, Pb, and aoPWV were significant independent predictors of maximum workload, whereas AP, AIx75, Pf, Pb, and aoPWV were independently related to peak VO2. Pulsatile hemodynamics are independently associated with objective measures of exercise capacity in patients with normal LVEF.