Cardiac dysfunction rather than aortic valve stenosis severity drives exercise intolerance and adverse hemodynamics

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Background Aortic valve stenosis (AS) and heart failure with preserved ejection fraction (HFpEF) present with similar cardiac alterations, but their overlap is poorly understood.(1–3). Purpose To study left ventricular (LV) hypertrophy, diastolic dysfunction, left atrial (LA) dysfunction, hemodynamics, and exercise capacity according to HFpEF status versus AS severity. Methods Patients (n=206) with at least moderate AS (aortic valve area ≤0.85 cm2/m2) and discordant symptoms underwent cardiopulmonary exercise testing with simultaneous echocardiography. The population was stratified according to the probability of underlying HFpEF by the H2FPEF score [0–5 (AS/HFpEF-) vs. 6–9 points (AS/HFpEF+)] and AS severity (Moderate vs. Severe). Results Mean age was 73±10 years with 40% women. Stratification yielded 41 AS/HFpEF+ (20%) versus 165 AS/HFpEF- (80%) and 139 Severe (67%) versus 67 Moderate (33%) AS patients. AS/HFpEF+ patients had a lower LV global longitudinal strain, impaired diastolic function, reduced LV compliance, and more pronounced LA dysfunction compared to AS/HFpEF- patients. The mean pulmonary arterial pressure-cardiac output (mPAP/CO) slope was significantly higher in AS/HFpEF+ versus AS/HFpEF- (5.4±3.1 vs. 3.9±2.2 mmHg/L/min, respectively; p = 0.003), mainly driven by impaired cardiac output (CO) reserve and chronotropic incompetence, with signs of right ventricular-pulmonary arterial (RV-PA) uncoupling. AS/HFpEF+ versus AS/HFpEF- was associated with a lower peak aerobic capacity (11.5±3.7 vs. 15.9±5.9 mL/min/kg, respectively; p<0.0001), but did not differ between Moderate and Severe AS (14.7±5.5 vs. 15.2±5.9mL/min/kg, respectively; p = 0.6). Conclusions A high H2FPEF score is associated with a reduced exercise capacity and adverse hemodynamics in patients with moderate to severe AS. Both exercise performance and hemodynamics correspond better with intrinsic cardiac dysfunction than AS severity itself.