Abstract Body (Do not enter title and authors here): Background
Left ventricular ejection fraction (LVEF) is traditionally used for cardiac risk stratification but may miss subclinical myocardial dysfunction. Left ventricular global longitudinal strain (GLS) may better reflect early systolic impairment. We investigated the association between GLS and major adverse cardiac events (MACE) in kidney transplant (KT) recipients with preserved pre-transplant LVEF (≥55%). We hypothesized that abnormal pre-transplant GLS would be associated with a higher incidence of MACE.
Methods
In this retrospective study, KT recipients from January 2015 to December 2023 with LVEF ≥55% on pre-transplant echocardiograms were included. Investigators achieved ≥80% interobserver agreement with the principal investigator on a random sample before GLS measurement using TomTec software. Patients were grouped as abnormal GLS (AbGLS, worse than –16%) vs. normal GLS (NGLS) per current American Society of Echocardiography guidelines. The primary outcome was MACE: cardiovascular death, non-fatal myocardial infarction, stroke, revascularization, angina, heart failure hospitalization, or fatal arrhythmia. Multivariable logistic regression adjusted for significant pre-transplant group differences. Kaplan-Meier survival analysis was also performed.
Results
Among 520 recipients, 309 had preserved LVEF (≥55%) and analyzable pre-transplant GLS; 153 had AbGLS and 156 had NGLS. Mean follow-up was 5.05 years in AbGLS and 5.38 years in NGLS. MACE occurred more frequently in AbGLS patients (27.5% vs. 15.4%, p=0.014). AbGLS patients were more likely to be male (62.7% vs. 48.1%, p=0.013), older (56.0 vs. 51.7 years, p=0.004), diabetic (45.8% vs. 27.6%, p=0.001), and have coronary artery disease (36.6% vs. 22.4%, p=0.009). Differences in LVEF, hypertension, smoking, stroke, heart failure, and arrhythmia were not significant. In multivariable regression, GLS as a continuous variable showed a trend toward predicting MACE (OR 0.94, 95% CI 0.87–1.01, p=0.075), and abnormal GLS as a binary variable also trended toward significance (OR 0.56, 95% CI 0.31–1.02, p=0.060). Coronary artery disease remained a significant predictor of MACE (OR 2.28, 95% CI 1.20–4.31, p= 0.011). Kaplan-Meier analysis showed significantly lower MACE-free survival in AbGLS vs. NGLS patients (p=0.0014).
Conclusion
GLS can aid in risk stratifying MACE in KT candidates with preserved pre-transplant LVEF. Lower GLS values were associated with increased post-transplant cardiovascular risk.