Reevaluating Heart Transplant Compatibility: A Retrospective Analysis Using Echocardiographic Left Ventricular Mass...

Area of Science:

• Cardiology
• Transplantation Surgery
• Medical Informatics

Background:

• Accurate donor-recipient size matching is critical for adult heart transplantation success.
• The optimal metric for assessing donor heart size acceptability remains debated.
• Current metrics may not fully capture the nuances of size matching.

Purpose of the Study:

• To compare the predicted heart mass ratio (PHMr) with the measured donor left ventricular mass to predicted recipient left ventricular mass (mLVM:pLVM) ratio.
• To evaluate how these metrics classify donor heart size acceptability.
• To identify potential disparities in classification based on donor characteristics.

Main Methods:

• Retrospective analysis of 594 adult donor offers evaluated at a single center.
• Classification of offers using bilateral windows and lower-bound-only thresholds for PHMr and mLVM:pLVM.
• Statistical analysis using recipient-clustered models, generalized estimating equations, and linear mixed models.

Main Results:

• PHMr classified more offers as acceptable than mLVM:pLVM under bilateral windows (46.3% vs. 40.1%), though not always significantly.
• Low agreement (Cohen's κ 0.12–0.24) was observed between the two metrics.
• Classification differences varied significantly by donor sex, with PHMr favoring male donors and mLVM:pLVM favoring female donors.

Conclusions:

• The selection of metric and threshold influences donor heart offer classification.
• Observed differences indicate operational discordance rather than inherent clinical superiority.
• Further validation of these metrics against transplant outcomes is warranted.