Predictive Efficacy of the Index of Microcirculatory Resistance for Acute Allograft Rejection and Cardiac Events After Heart Transplantation: A Systematic Review and Meta-Analysis.

Abstract

In patients treated by heart transplantation, the index of microcirculatory resistance (IMR) has been found to have predictive potential for subsequent acute allograft rejection (AAR) and long-time cardiac events. When consulting related literature, the studies mostly were single-center with small sample sizes. The question of whether IMR can be utilized as a predictive biomarker is becoming increasingly contentious. To confirm the predictive efficacy of IMR, researchers did a systematic review and meta-analysis. From inception to April 2022, PubMed, EMBASE, Cochrane Library, Web of Science, Ovid, ProQuest, and Scopus systematically were searched. The results were presented as pooled ratio rate (RR) with 95% confidence intervals (CI). Assessment of the quality, heterogeneity analyses, and publication bias analysis also were performed. A total of 616 patients were studied in five trials. There were significant differences in subsequent AAR (RR = 4.08; 95% CI: 2.69~6.17; P = 0.000) or long-time cardiac events (RR=2.14; 95% CI: 1.44~3.19; P = 0.000) between IMR-high and IMR-low patients in the forest plots. Patients treated with heart transplantation in the high IMR group had better predictive efficacy than the low IMR group. High IMR could predict the events of subsequent AAR and cardiac events after heart transplantation. This will help reduce the occurrence of adverse events and personalize treatment for patients.