No Evidence for Oversizing Hearts and Donor Size Impact on 1-Year Survival in Heart Failure Patients With Left...

Area of Science:

• Cardiology
• Transplantation Surgery
• Medical Metrics

Background:

• Donor-to-recipient size-matching is critical for heart transplant outcomes.
• The predicted heart mass (PHM) ratio is a novel metric outperforming traditional weight ratios.
• Its utility in patients supported by left ventricular assist devices (LVADs) remains unestablished.

Purpose of the Study:

• To evaluate the effectiveness of the PHM ratio for size-matching in heart transplant recipients with LVAD support.
• To compare the PHM ratio against other size-matching metrics (weight, height, BMI, BSA) in this specific population.

Main Methods:

• Retrospective analysis of 11,891 heart transplant recipients with LVAD support from the Scientific Registry of Transplant Recipients (1997-2020).
• Comparison of five size-matching metrics: donor-recipient ratios of weight, height, body mass index, body surface area, and PHM.
• Application of single and multivariable Cox proportional hazards models to assess 1-year mortality.

Main Results:

• The PHM ratio demonstrated superior risk stratification compared to other metrics in LVAD patients.
• Patients receiving undersized donor hearts (PHM ratio <0.83) exhibited a significantly increased hazard ratio for 1-year mortality (1.34, p=0.007).
• No significant difference in mortality was observed between matched (0.83-1.2) and oversized (≥1.2) donor heart groups.

Conclusions:

• The PHM ratio is an optimal metric for donor-recipient size-matching in heart transplant candidates on LVAD support.
• Utilizing undersized donor hearts (PHM ratio <0.83) is associated with higher 1-year mortality.
• Employing oversized donor hearts in LVAD recipients does not confer survival benefits.