Predicting major events in ambulatory patients with advanced heart failure awaiting heart transplantation: a pilot study

Abstract

Aims: In heart failure (HF), prognostic risk scores focus on all-cause mortality prediction. However, in advanced HF (AdHF) ambulatory patients awaiting heart transplantation (HTx), hospitalizations for acutely decompensated/worsening HF are relevant to clinical decision-making, but unpredicted by common risk functions.

Methods: Among consecutive ambulatory patients added to the waitlist for HTx, event discriminators within 2 years from recruitment were assessed prospectively by area under the curve from receiver-operating characteristic curves, and by Cox proportional hazards models. Primary composite end points included the first between all-cause mortality and acutely decompensated/worsening HF requiring hospitalization and specific treatments.

Results: In 89 patients, 36 primary composite events were recorded in a 2-year follow-up (40% of the study sample), and associated with nonischemic etiology and nonsinus rhythm, with lower systolic blood pressure (BP), lower plasma sodium and hemoglobin concentrations, and with higher N-terminal pro-brain natriuretic peptide (NT-proBNP), larger left ventricular (LV) dimensions and lower LV ejection fraction, greater proportion of significant mitral regurgitation, lower tricuspid annulus peak systolic excursion (TAPSE), lower percentage of predicted distance at 6-minute walking test (%p6MWT) and lower global symptoms burden by the Kansas City Cardiomyopathy Questionnaire, lower peak oxygen uptake by cardiopulmonary exercise, and higher wedge pressure by right heart catheterization, as compared with those with no events (P < 0.05). Only Metabolic Exercise Cardiac Kidney Index (MECKI) at recruitment was higher with patients reporting events, which predicted composite end points in addition to and independently of NT-proBNP, and lower systolic BP (all P < 0.05). In an alternative risk model, severe mitral regurgitation and lower TAPSE replaced MECKI and BP but not NT-proBNP (all P < 0.01).

Conclusion: Higher NT-pro-BNP, lower systolic BP and higher MECKI may contribute to predicting all-cause death and acutely decompensated/worsening HF among ambulatory patients awaiting HTx, with lower TAPSE and severe mitral regurgitation representing further alternative independent prognosticators.