Abstract Body (Do not enter title and authors here): Background: Left ventricular assist devices (LVADs) are crucial for the management of advanced heart failure patients acting, both as a bridge to heart transplant or destination therapy. Existing studies revealed mixed results on the impact of pre-implant left ventricular end-diastolic diameter (LVEDD) on post-LVAD mortality. Some studies found smaller LVEDD increases mortality, while others revealed no significant impact. Due to the limited evidence, this meta-analysis aims to determine the association between pre-LVEDD and post-LVAD implantation mortality through a systematic review and meta-analysis.

Method: We systematically reviewed articles until May 2024 examining the association between pre-implant LVEDD and post-LVAD implantation mortality using PubMed, Google Scholar, Embase, and Scopus. A random effects model was used to calculate the pooled adjusted odds ratio (aOR). We used I² statistics to determine the heterogeneity of studies. Leave-one-out sensitivity analysis was done to evaluate each study's effect on the overall estimate, with statistical significance set at p<0.05.

Results: We included four studies in our meta-analysis, three from the USA and one multicountry study, totaling 16,548 LVAD recipients (13,110 males and 3,438 females). We examined the relationship between pre-implant left ventricular end-diastolic diameter (LVEDD) and mortality following continuous LVAD implantation. The random-effects model revealed a significant association between smaller LVEDD and increased mortality, with a pooled adjusted odds ratio (aOR) of 1.29 [95% confidence interval (CI): 1.10 – 1.53, p < 0.01]. Leave-one-out sensitivity analysis validated the robustness of our findings, identifying the study by Dual et al. as the most influential. We observed low heterogeneity among the included studies (I²=22.38 %, P=0.28), suggesting consistent results across different populations and settings.

Conclusion: Our study demonstrates a significant association between small pre-implant LVEDD and higher post-LVAD implantation mortality when compared to large pre-implant LVEDD. Overall, our results underscore the need for careful assessment of LVEDD in clinical decision-making and patient management for those undergoing LVAD implantation.