588 EXPLORING THE IMPACT OF SEVERE SECONDARY TRICUSPID REGURGITATION ON REST AND EXERCISE HEMODYNAMICS OF PATIENTS WITH HEART FAILURE AND A PRESERVED LEFT VENTRICULAR EJECTION FRACTION

Abstract Background Both secondary tricuspid regurgitation (STR) and heart failure with preserved ejection fraction (HFpEF) are relevant public health problem in the elderly population, presenting with potential overlaps and sharing similar risk factors. However, the impact of severe STR on hemodynamics and cardiorespiratory adaptation to exercise in HFpEF remains to be clarified. Aim To explore the impact of severe STR on exercise hemodynamics and cardiorespiratory adaptation in HFpEF. Methods We analyzed invasive hemodynamics and gas-exchange data obtained at rest and during exercise from HFpEF patients with severe STR (HFpEF-STR), compared with 1:1 age, sex and body mass index matched HFpEF patients with mild or no STR (HFpEF-controls). Results 13 HFpEF-STR (mean age 72 years, 85% females, BMI 28 Kg/m2) and 13 age-, sex-, and BMI-matched HFpEF-controls patients were included. HFpEF-STR had higher (p<0.01) right atrial pressure than HFpEF-controls both at rest (10±1 vs 5±1 mmHg) and during exercise (23±2 vs 14±2). During exercise, pulmonary artery wedge pressure as well as left ventricular transmural pressure increased less in HFpEF-STR than in HFpEF-controls (interaction p-value<0.05). Similarly, cardiac output (CO) increased less in HFpEF-STR than in HFpEF-controls (interaction p-value<0.05) during exercise, due to the lower stroke volume (SV) values both at rest (49±8 vs 78±8, p<0.05) and at peak exercise (55±9 vs 92±9 mL, p<0.05). Despite these differences, the two groups of patients laid on the same oxygen consumption isophlets because of the increased peripheral oxygen extraction in HFpEF-STR (p<0.01). An inverse relationship was found between pulmonary vascular resistance and SV, both at rest and at peak exercise (R2=0.12 and 0.19, respectively). Conclusions Severe STR complicating HFpEF impairs SV and CO reserve, leading to pulmonary vascular de-recruitment and relative left heart underfilling, mining the typical HFpEF pathophysiology. Exercise pathophysiology of secondary tricuspid regurgitation (STR) in heart failure with preserved ejection fraction (HFpEF).