Calculation of pulmonary capillary wedge pressure including left atrial function is superior to morphology alone and accurately identifies HFpEF patients

Heart failure with preserved ejection fraction (HFpEF) is on the rise. Right heart catheterisation (RHC) with pulmonary capillary wedge pressure (PCWP) assessment is the diagnostic reference standard, remains however underused. Different approaches for non-invasive PCWP calculation have been proposed. However, as left atrial strain (LA Es) and volume index (ESVi) emerge as a key criteria in HFpEF, we sought to investigate them for PCWP calculation.

The derivation population consisted of patients referred to RHC and cardiovascular magnetic resonance (CMR) imaging who were enrolled in a prospective monocentric registry. Patients were classified by RHC according to current guideline recommendations. CMR assessment included left ventricular (LV) volumes and atrial phasic deformation imaging. The validation population consisted of patients included in the HFpEF-Stress trial who underwent exercise-stress RHC and CMR with follow-up after 4 years for hospitalised cardiovascular events. Strain-derived PCWP was compared to a published LA volume (LAV) and LV mass (LVM) derived method.

The derivation population consisted of n=209 patients, n=123 underwent exercise-stress RHC (n=55 without PH, n=72 pre-capillary, n=26 CpcPH, n=16 IpcPH, n=34 exercise and n=6 unclassified PH). Linear regressions models identified the following formulae for PCWPrest 10.304-0.095*Es+0.098*ESVi and PCWPstress 24.666-0.251*Es+0.056*ESVi calculation.

The validation population consisted of n=74 patients (n=15 without, n=5 pre-capillary, n=8 CpcPH, n=10 IpcPH and n=32 exercise PH with n=4 remaining unclassified). Calculated PCWPrest (11.8) and RHC-derived PCWPrest (11mmHg) were statistically similar (p=0.285) and showed good correlation (r=0.53, p<0.001). Calculated PCWPrest (AUC 0.80) and PCWPstress (AUC 0.85) accurately identified HFpEF patients, were superior to LAV/LVM based PCWP (AUC 0.67, p≤0.002) and showed prognostic implications (HR 1.37 (1.16-1.62) and 1.29 (1.14-1.46), p<0.001).

Calculated PCWP accurately identifies post-capillary involvement in PH and shows distinct prognostic implications. It may be suited to detect LV involvement in PH.