Trends in utilization, outcomes, and readmissions after transcatheter mitral valve replacement

Application of machine learning to predict in-hospital mortality after transcatheter mitral valve repair

INTRODUCTION

Transcatheter mitral valve repair offers a minimally invasive treatment option for patients at high risk for traditional open repair. We sought to develop dynamic machine-learning risk prediction models for in-hospital mortality after transcatheter mitral valve repair using a national cohort.

METHODS

All adult hospitalization records involving transcatheter mitral valve repair were identified in the 2016-2020 Nationwide Readmissions Database. As a result of initial class imbalance, undersampling of the majority class and subsequent oversampling of the minority class using Synthetic Minority Oversampling TEchnique were employed in each cross-validation training fold. Machine-learning models were trained to predict patient mortality after transcatheter mitral valve repair and compared with traditional logistic regression. Shapley additive explanations plots were also developed to understand the relative impact of each feature used for training.

RESULTS

Among 2,450 patients included for analysis, the in-hospital mortality rate was 1.8%. Naïve Bayes and random forest models were the best at predicting transcatheter mitral valve repair postoperative mortality, with an area under the receiver operating characteristic curve of 0.83 ± 0.05 and 0.82 ± 0.04, respectively. Both models demonstrated superior ability to predict mortality relative to logistic regression (P < .001 for both). Medicare insurance coverage, comorbid liver disease, congestive heart failure, renal failure, and previous coronary artery bypass grafting were associated with greater predicted likelihood of in-hospital mortality, whereas elective surgery and private insurance coverage were linked with lower odds of mortality.

CONCLUSION

Machine-learning models significantly outperformed traditional regression methods in predicting in-hospital mortality after transcatheter mitral valve repair. Furthermore, we identified key patient factors and comorbidities linked with greater postoperative mortality. Future work and clinical validation are warranted to continue improving risk assessment in transcatheter mitral valve repair .

Economic Disparities in Utilization and Outcomes of Structural Heart Disease Interventions in the United States

Background

Disparities in access to care cause negative health consequences for underserved populations. Economic disparities in structural heart disease (SHD) interventions are not well characterized.

Objectives

The objective of this study was to evaluate economic disparities in the utilization and outcomes of SHD interventions in the United States.

Methods

We queried the National Inpatient Sample (2016-2020) to examine economic disparities in the utilization, in-hospital outcomes, length of stay, and cost of SHD interventions among patients ≥65 years of age. Outcomes were determined using logistic regression models.

Results

A total of 401,005 weighted hospitalizations for transcatheter aortic valve replacement, left atrial appendage occlusion, transcatheter mitral valve repair, and transcatheter mitral valve replacement were included. Utilization rates (number of procedures performed per 100,000 hospitalizations) were higher in patients with high income compared with medium and low income for transcatheter aortic valve replacement (559 vs 456 vs 338), left atrial appendage occlusion (148 vs 136 vs 99), transcatheter mitral valve repair (65 vs 54 vs 41), and transcatheter mitral valve replacement (7.7 vs 6.7 vs 1.2) (all P < 0.01). Low- and medium-income patients had distinctive demographic and clinical risk profiles compared with high-income patients. There were no significant differences in the adjusted in-hospital mortality, key complications, or length of stay between high-, medium-, and low-income patients following any of the 4 SHD interventions. High-income patients incurred a modestly higher cost with any of the 4 SHD interventions compared with medium- and low-income patients.

Conclusions

Economic disparities exist in the utilization of SHD interventions in the United States. Nonetheless, adjusted in-hospital outcomes were comparable among high-, medium-, and low-income patients. Multifaceted implementation strategies are needed to attenuate these utilization disparities.

Mortality and resource utilization in surgical versus transcatheter repeat mitral valve replacement: A national analysis

BACKGROUND

Transcatheter mitral valve replacement (TMVR) has garnered interest as a viable alternative to the traditional surgical mitral valve replacement (SMVR) for high-risk patients requiring redo operations. This study aims to evaluate the association of TMVR with selected clinical and financial outcomes.

METHODS

Adults undergoing isolated redo mitral valve replacement were identified in the 2016-2020 Nationwide Readmissions Database and categorized into TMVR or SMVR cohorts. Various regression models were developed to assess the association between TMVR and in-hospital mortality, as well as additional secondary outcomes. Transseptal and transapical catheter-based approaches were also compared in relation to study endpoints.

RESULTS

Of an estimated 7,725 patients, 2,941 (38.1%) underwent TMVR. During the study period, the proportion of TMVR for redo operations increased from 17.8% to 46.7% (nptrend<0.001). Following adjustment, TMVR was associated with similar odds of in-hospital mortality (AOR 0.82, p = 0.48), but lower odds of stroke (AOR 0.44, p = 0.001), prolonged ventilation (AOR 0.43, p<0.001), acute kidney injury (AOR 0.61, p<0.001), and reoperation (AOR 0.29, p = 0.02). TMVR was additionally correlated with shorter postoperative length of stay (pLOS; β -0.98, p<0.001) and reduced costs (β -$10,100, p = 0.002). Additional analysis demonstrated that the transseptal approach had lower adjusted mortality (AOR 0.44, p = 0.02), shorter adjusted pLOS (β -0.43, p<0.001), but higher overall costs (β $5,200, p = 0.04), compared to transapical.

CONCLUSIONS

In this retrospective cohort study, we noted TMVR to yield similar odds of in-hospital mortality as SMVR, but fewer complications and reduced healthcare expenditures. Moreover, transseptal approaches were associated with lower adjusted mortality, shorter pLOS, but higher cost, relative to the transapical. Our findings suggest that TMVR represent a cost-effective and safe treatment modality for patients requiring redo mitral valve procedures. Nevertheless, future studies examining long-term outcomes associated with SMVR and TMVR in redo mitral valve operations, are needed.

Impact of sex on in-hospital mortality and 90-day readmissions in patients undergoing transcatheter mitral valve replacement (TMVR): Analysis from the nationwide readmission database

OBJECTIVES

To evaluate sex differences in in-hospital mortality and 90-day readmission rates among patients undergoing transcatheter mitral valve replacement (TMVR) in the United States of America.

BACKGROUND

Women have higher rates of mortality and rehospitalization than men following many cardiac procedures. TMVR has grown as an alternative to mitral valve surgery for patients at high surgical risk. The rates of TMVR mortality and rehospitalization by sex are unknown.

METHODS

We analyzed the Nationwide Readmissions Database (NRD) from 2016 to 2019 to identify hospitalizations for TMVR. Sex differences in in-hospital mortality and 90-day readmissions were determined using logistic regression models.

RESULTS

Between 2016 and 2019, 4109 hospitalizations for TMVR were identified, comprised of 1758 (42.8%) men and 2351 (57.2%) women. The median age was 74 years for both men and women. There was no significant difference in in-hospital mortality during index hospitalization (6.51% vs. 6.69%; p = 0.852) and all-cause 90-day readmission (28.19% vs. 29.59%; p = 0.563) between men and women. Across the study period, trend analysis did not reveal a significant change in in-hospital mortality (men p = 0.087, women p = 0.194) or 90-day readmission rates (men p = 0.569, women p = 0.454).

CONCLUSIONS

In patients undergoing TMVR, in-hospital mortality and 90-day readmissions are similar between men and women. Between 2016 and 2019, TMVR in-hospital mortality and 90-day readmission rates remained unchanged. Further research is necessary to confirm these findings.