Select episodes of acute cardiac rejection after orthotopic heart transplantation, not affecting the global longitudinal strain during a 2-year observation period

Abstract Background Acute cardiac rejection (ACR) is a common complication following orthotopic heart transplantation (HTx), which can be detected by impairment of left ventricle global longitudinal strain (LVGLS). It remains unclear whether changes in GLS after ACR are reversible. Purpose This study aimed to evaluate the impact of episodes on GLS of the left ventricle over a 2-year observation period in HTx recipients. Materials and Methods One hundred consecutive patients who underwent HTx between January 2021 and May 2023 were prospectively enrolled in the study. During a 2-year observation period, echocardiographic examinations assessing LVGLS were performed following routine endomyocardial biopsies (EMB). Based on the presence of severe ACR which was identified in EMB as grade 3, patients were categorized into two groups: ACR+ (those with episodes of severe ACR) and ACR- (those without episodes of severe ACR) during the 2-year observation period. Exclusion criteria included poor imaging quality (n=3), death within the first 6 months post-transplant (n=21), death during the observation period due to neoplastic disease (n=3), individuals undergoing re-HTx (n=3), and patients with chronic rejection (n=1). Results A total of 69 patients were included in the study: 49 in the ACR- group, with a median age of 51 (IQR 44-59) and 84% male, and 20 in the ACR+ group, with a median age of 56 (IQR 49-63.5) and 80% male, p=0.19. The frequency of arterial hypertension and diabetes mellitus was similar in the ACR- and ACR+ groups [ 20 (41%) vs.12 (60%), p=0.15; 9 (18) vs.7 (35), p=0.14 respectively]. There were no significant differences in cold ischemia time and donor age between the studied groups: 132 (IQR 96-161) minutes for the ACR- group and 153 (IQR 119-194) minutes for the ACR+ group (p=0.635). The donor age was 42 years (IQR 36-48) for the ACR- group and 36 years (IQR 28-46.5) for the ACR+ group (p=0.13). There were no statistically significant differences in GLS values between the groups at 6 months (15.2 (IQR 13.8-17.5) vs. 13.5 (IQR 13.1-16.0), p=0.22), 12 months (15.3 (IQR 13.8-16.8) vs. 14.4 (IQR 12.9-16.5), p=0.35), and 24 months (15.9 (IQR 14.3-17.6) vs. 15.4 (IQR 13.7-16.0), p=0.35). The Friedman ANOVA analysis did not reveal any differences in GLS among repeated measurements at 6, 12, and 24 months in ACR- and ACR+ groups ( p=0.46, p=0.27). Conclusion The value of GLS after HTx does not change significantly during the observation period. Over the 2-years post-HTx, experiencing ACR episodes does not affect left ventricle systolic function as assessed by GLS.