Abstract 13262: Right to Left Ventricular Interdependence at Rest and During Exercise Assessed by the Ratio Between Pulmonary Systolic to Diastolic Time in Heart Failure Reduced Ejection Fraction

Abstract

Background: The ratio between the duration of right ventricular (RV) systole and diastole (S:D ratio) has been proposed as an index of RV performance in a pediatric population with pulmonary arterial hypertension in whom it may predict prognosis and functional capacity. In heart failure (HF) S:D may provide relevant insights in the exercise response. Aim: to analyze the correlation between rest and peak exercise S:D and functional and cardiac parameters in HFrEF. Methods: 94 HFrEF patients (mean age 66±11 y, male 70%, ischemic etiology 71%, mean LVEF 34±9%) underwent a symptom-limited cardiopulmonary exercise testing (incremental ramp protocol) combined with exercise-echo. RV S:D was assessed by echo at rest and peak exercise. Results: A good correlation was found between rest and peak S:D and CPET indexes of exercise capacity, such as peak oxygen consumption (VO2) (Sperman’s rho -0.40 and 0.38 respectively, p= 0.02 and 0.023) and maximal workload (Rho= -0.42 and -0.45, p=0.031 and 0.034). An higher S:D also correlated with more impaired ventilatory efficiency or higher VE/VCO2 slope (Rho 0.49 and 0.32, p=0.019 and 0.024). Looking at echo phenotype, interestingly S:D is associated with parameters of mitral regurgitation (MR) severity, such as effective regurgitant orifice (Rho rest 0.63, peak 0.35, p<0.01) and pulmonary artery systolic pressure (PASP, rho rest 0.53, peak 0.35, p<0.01) particularly at rest. S:D also correlated with right RV fractional area change at rest and peak exercise (-0.39 and -0.39, p=0.035 and 0.04). Conclusions: In HFrEF population the assessment of S:D at rest and peak exercise predicts functional status and is related to more advanced hemodynamic impairment (increased PASP and MR) as expression of more unfavorable ventricular interdependence.