Echocardiographic estimate of pulmonary capillary wedge pressure improves outcome prediction in chronic heart failure

Abstract

Background
An echocardiographic algorithm to estimate pulmonary capillary wedge pressure (ePCWP) and pulmonary vascular resistance (ePVR) has been recently validated versus right heart catheterization (1).

Purpose
The aim of this study was to assess the prognostic significance of these measures in heart failure (HF) patients.

Methods
Consecutive outpatients with HF and left ventricular ejection fraction (LVEF) <50% undergoing echocardiography were selected and followed-up for the composite endpoint of cardiac death or HF hospitalization.

Results
Out of 2,214 patients (71±12 years, 76% males, LVEF 35±9%), ePCWP (16±6 mmHg) was elevated (>15 mmHg) in 52% of cases and ePVR (1.7±0.7 WU) was elevated (>2 WU) in 25% of cases. Patients with increased ePCWP were older, had a higher NYHA class, more pronounced cardiac remodeling, systo/diastolic dysfunction, and neurohormonal activation, particularly when ePVR was also elevated (p<0.001). Over a median follow-up of 33 (17-48) months, both measures stratified patients for the risk of the primary endpoint (Log-Rank 152 for PCWP, and 44 for ePVR, p<0.001). At adjusted regression analysis, ePCWP (hazard ratio for 1 mmHg increase 1.03 [95%CI 1-01-1-05], p<0.001) but not ePVR (p=0.584) predicted the primary endpoint, even in the subpopulation of patients with atrial fibrillation (p=0.003). ePCWP outperformed current diastolic dysfunction grading (Δ C-statistics 0.068 [95% CI 0.045-0.093], p<0.001), and stratified patients’ risk across each diastolic dysfunction grade at univariate analysis (Grade I: p=0.002; Grade II-III: p<0.001; Indeterminate cases: p=0.010). The addition of ePCWP to a multivariable prognostic model, including patients’ age, NYHA class III-IV, chronic obstructive pulmonary disease, estimated glomerular filtration rate, NT-proBNP, and LVEF, improved the accuracy of risk prediction (Δ C-statistics 0.008 [95% CI 0.002-0.014], p=0.007).

Conclusion
The echocardiographic estimates of PCWP retained clinical and prognostic significance in a large contemporary cohort of patients with chronic HF and LVEF <50%. This algorithm could facilitate early identification of high-risk patients, possibly reducing the need of right heart catheterisation, and allowing a tailored therapeutic approach.
Graphical abstract
KM curves for the primary endpoint - AF