Integrating Resistant and Pulsatile Right Ventricular Load Improves Severity Assessment in Heart Failure Patients

The 2022 European Society of Cardiology/European Respiratory Society (ESC/ERS) pulmonary hypertension definition only consider resistant right ventricular (RV) load (pulmonary vascular resistance [PVR]), but not pulsatile load (pulmonary artery compliance [PAC]) known to be important.

The authors aimed to compare severity-grading of RV afterload using the current pulmonary hypertension definition with a novel RV afterload score and investigate the PVR-PAC relation in patients with heart failure.

We included patients (n = 328) with reduced left ventricular ejection fraction (<50%) consecutively referred for right heart catheterization. For PVR and PAC separately, we allocated points for low (0 points), intermediate (1 point), and high (2 points) afterload. After summing the points, 0, 1 to 2, and 3 to 4 defined low, intermediate, and high RV afterload. The primary endpoint was all-cause mortality or a left ventricular assist device implantation.

The RV afterload score was superior in severity stratification compared with ESC/ERS phenotypes with stepwise significant differences (P < 0.001) in RV function, cardiac index, pulmonary artery wedge pressure, and prognostic value (P = 0.010). Compared with a low afterload score, the adjusted HR (95% CI) for a high score was 4.42 (1.86-10.6). The hyperbolic PVR-PAC relation (R² = 0.48), allowed definition of 3 PVR zones: ≤2 WU with 56% low and 44% intermediate, 2.1 to 3.9 WU with 67% intermediate and 33% high load, and ≥4 WU with 100% high afterload score.

We describe a novel RV afterload score that improves severity grading and prognostication compared with current ESC/ERS phenotypes and define PVR-intervals that might be helpful for therapy individualization and in upcoming trials with new therapeutic targets.