Understanding the Impact of Comorbidity-Interaction in Patients Undergoing Transcatheter Edge-to-Edge Mitral Valve Repair on Outcomes

BACKGROUND Transcatheter Edge-to-Edge Mitral Valve Repair (M-TEER) is an accepted procedure for high-risk surgical patients with degenerative and functional mitral regurgitation. Non-cardiovascular comorbidities (NCCs) are highly prevalent in patients undergoing M-TEER. Although the impact of mitral valve anatomy and cardiac comorbidities in determination of M-TEER outcomes has been studied, precise understanding of the effect of the burden of NCCs on patients undergoing M-TEER remains unclear for acute outcomes. Our objective was to identify the association of NCC comorbidity-interaction patterns in patients undergoing M-TEER on length of stay (LOS), cost of care, and in-hospital major adverse cardiovascular events (MACE). METHODS 9 245 admissions from the Nationwide Readmission Database that underwent M-TEER between 2015 and 2018 were included in the study. Patients were categorized by the overall burden of non-cardiovascular comorbidities (0, 1, 2, and ≥ 3). NCC included chronic liver disease, chronic lung disease, obesity, diabetes mellitus, dementia, major depressive disorder, chronic anemia, chronic kidney disease including end-stage renal disease (ESRD) on dialysis, and malignancy. Logistic Regression and Machine Learning (ML) algorithms were used to assess associations between comorbidity burden and in-hospital MACE. RESULTS Out of 9 245 index admissions, in-hospital MACE was recorded in a total of 504 (5.3 %). Of these, the majority (30.4%) had one NCC (n = 2 861). Patients with at least three NCCs had the longest median LOS [3.0, IQR (1.0 – 11.0)] and highest median cost of hospital care [$47 275, IQR (34 175.8 – 71 149.4)]. The Gradient Boosting (GB) classifier performed the best in predicting MACE with an AUROC of 96 % (95% CI: 0.95 – 0.97). The top features of importance that predicted in-hospital MACE were admission type, number of NCCs, and age in descending order. CONCLUSIONS Calibrated GB classifier identified patients with three NCCs as the subset of admission having the highest probability of a positive MACE outcome. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was possible with a generous gift from Jennifer and Robert McNeil. The funders had no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, and in the preparation, review, or approval of the manuscript. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: No IRB approval was needed as this study utilized a publicly available deidentified data from National Readmission Database I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The US Healthcare Cost and Utilization Project's Nationwide Readmissions Database is a publicly available dataset that can be accessed at