Interrelation of right ventricular contraction and contractility in heart failure with preserved ejection fraction

Aims Assessment of right ventricular (RV) systolic function remains challenging despite its clinical importance and prognostic relevance. Complementary to load-dependent contraction, pressure-volume (PV) loop analysis allows evaluation of load-independent contractility. This study aimed to investigate the interrelation and prognostic relevance of RV contraction and contractility in HFpEF and to develop a non-invasive PV loop approach to facilitate broader clinical applicability. Methods Prior to invasive assessment patients underwent cardiac magnetic resonance imaging to derive RV contraction (ejection fraction, RVEF). In PV loop analysis end-systolic elastance (Ees), the X-axis intercept (V0) of the end-systolic PV relationship, and the indexed volume at an end-systolic pressure (ESP) of 40 mmHg (RV-V40i) was determined (Figure 1). Non-invasive contractility was derived from reconstructed PV loops from correlations between invasive and imaging parameters. Survival was analyzed according to median RV-V40i defining normocontractile (≥median) and hypercontractile ( Results Fifty-two patients (median age 72 years, 67% female) were included, with a median follow-up of 4.5 years. While clinical presentation was comparable to normocontractile (RV-V40i ≥median) patients, hypercontractile cohort showed smaller ventricles (EDV index 63ml/m² [IQR 58 to 77] vs. 70ml/m² [IQR 63 to 85], p=0.041), higher RVEF (64% [IQR 55 to 68] vs. 57% [IQR 47 to 61], p=0.010), and elevated ESP (p<0.05 for all). Invasive and non-invasive PVL parameters demonstrated strong correlations for RV-ESP (r=0.95, p<0.001), RV-V0 (r=0.75, p<0.001), RV-Ees (r=0.73, p<0.001) and RV-V40i (r=0.85, p<0.001). Although each was individually associated with survival, integrating RV contraction (RVEF) and contractility (RV-V40i) identified highest mortality in hypercontractility but lowest contraction. Non-invasive measures closely resemble PV loop parameters and association to survival (Figure 2 A+B). Conclusion Beyond diastolic stiffness, hypercontractility is increasingly recognized as a key feature of HFpEF pathophysiology. RV hypercontractility appears to be more than a compensatory response. It is an independent determinant of long-term survival in HFpEF. Contrary to the conventional assumption that better RV systolic function predicts improved outcomes, patients with RV hypercontractility showed higher mortality predominantly in patients with worse contraction, likely reflecting increased RV afterload. The proposed concept of non-invasive RV PVL assessment bares the potential for broader application across cardiovascular diseases fostering our understanding of HFpEF.Figure 1Figure 2