Post-transplant diabetes is associated with late systolic dysfunction after heart transplantation

Background

Orthotopic heart transplantation (OHT) is an established treatment for end-stage heart failure. Post-transplant diabetes mellitus (PTDM) is a common complication of immunosuppressive therapy, but its longitudinal impact on left ventricular (LV) systolic function remains incompletely understood.

Methods

We retrospectively studied 102 OHT recipients (74% male, mean age 51±13 years; 37 with PTDM). Echocardiography was performed at 1, 3 and 5 years post-transplantation, including global longitudinal strain (GLS) and ejection fraction (EF). Blood pressure and HbA1c were recorded at each time point. Linear mixed-effects models evaluated the association between diabetes diagnosed at 1 year and subsequent systolic function, adjusting for age, sex and systolic blood pressure. Secondary models included time-varying HbA1c and cardiac allograft vasculopathy (CAV).

Results

At 1 year, no differences in EF or GLS were observed between groups. By 3 years, PTDM patients showed impaired GLS compared to non-diabetic recipients (p=0.022). At 5 years, EF was significantly lower in the PTDM group (p=0.002).

In mixed-effects models, diabetes at 1 year was associated with persistently impaired GLS (p=0.003), without a differential trajectory (diabetes×time p=0.192). For EF, diabetes was associated with lower overall values (p=0.010) and a trend toward greater decline over time (p=0.056), which became significant after adjustment for CAV (p=0.029). HbA1c and CAV were not independently associated with GLS.

Conclusion

Diabetes diagnosed at 1 year after OHT was associated with impaired systolic function at 5 years, reflected by lower EF and persistently worse GLS, suggesting a potential direct metabolic myocardial impact.GLS according to diabetes status at 1 yearEF according to diabetes status at 1 year