Echocardiographic Grading of Right Ventricular Afterload in Left Heart Disease: Relation to Right Ventricular Function, Pulsatile and Resistant Load, and Outcome.

Abstract

The hemodynamic definitions of pulmonary hypertension consider resistive loading (pulmonary vascular resistance [PVR]), but there are increasing evidence that pulsatile loading (pulmonary artery compliance [PAC]) has functional and prognostic importance. The aims of the present study on patients with left heart disease, were to evaluate a novel echocardiographic right ventricular (RV) afterload score and to investigate its relation to risk of mortality or implantation of a left ventricular assist device. Patients (n = 220) with left ventricular ejection fraction < 50% consecutively referred for heart transplant or heart failure workup underwent echocardiography and right heart catheterization. Four metrics were included in the afterload score: the systolic pulmonary artery pressure (sPAP_Doppler) and three variables related to pressure reflection in the pulmonary circulation. Two points were allocated for sPAP_Doppler ≥ 60 mmHg and for each pressure reflection variable indicating PVR > 3 Wood units (WU). One point was allocated for sPAP_Doppler 36-59 mmHg and for pressure reflection variables above the upper normal limit. Low afterload was defined as 0-to-1 points, intermediate as 2-to-4 points, and high as 5-to-8 points. There were in-between the groups significant differences in PAC and PVR. A 5-point RV dysfunction score showed with stepwise increased RV afterload more severe dysfunction. Unadjusted hazard ratio for endpoint was 3.34 (1.69-6.79) for intermediate score, and 5.11 (2.52-10.40) for patients with high score. In conclusion, in patients with severe heart failure, a novel echocardiographic RV afterload score is related to increased pulsatile and resistant load, more severe RV dysfunction, and increased risk of adverse outcome.