National prevalence and outcomes of different mitral valve interventions for mitral regurgitation among patients with cardiogenic shock: an analysis of the national readmission database 2010–2018

Abstract

Abstract Background Prevalence and outcome data of mitral valve (MV) interventions for severe mitral regurgitation (MR) in the setting of cardiogenic shock (CS) is limited. Purpose Our aim is to study the national prevalence, mortality, and outcomes of three mitral valve interventions (transcatheter mitral valve (MitraClip), surgical mitral valve repair (sMVR), and surgical mitral valve replacement (sMVr)) in patients with severe MR and CS, and how they compare to a non-invasive medical approach to management. Methods Patients with concomitant severe MR and CS were included for the years 2010 - 2018 from the national readmission database. We compared the national prevalence, in hospital mortality, readmission rate, and outcomes of patients who were treated either medically (non-invasive), or underwent an invasive approach with MitraClip, sMVR, or sMVr using one-way ANOVA and logistic regression. Results A total of 106,015 patients (68±13 years, 42% women) with severe MR and CS were identified. Of these, 88,696 (84%) were treated medically, while 607 (0.6%) underwent MitraClip, 4,528 (4%) underwent sMVR, and 12,184 (12%) underwent sMVr. Majority of patients in all four groups had a high Elixhauser comorbidity score of >6. In-hospital mortality rate was 31% in the medical therapy group, 14% and 17% in the sMVR and sMVr groups subsequently, and 26% in the MitraClip group (p<0.001). The median cost of hospitalization was significantly higher in the MitraClip group ($400,087) compared to the other groups (medical=$140,282, sMVR =$290,456, and sMVr =$353,688, p<0.001). Readmission rates were significantly lower in the sMVR (0.7%) and sMVr (1%) groups compared to the medical therapy (4%) and MitraClip (6%) groups (p<0.001). MitraClip was associated with a higher use of Impella (Odds Ratio (OR) 2.6; 95% Confidence Interval (CI) 1.8–3.8, p<0.001), intra-aortic balloon pump (IABP) (OR 3.8; 95% CI 2.9–5.1, p<0.001), and vasopressors (OR 1.6; 95% CI 1.1–1.7, p<0.001) than sMVR or sMVr. Extracorporeal membrane oxygenation (ECMO) use was more common in sMVR (OR 2.9, 95% CI 2.5–3.4, p<0.001) and sMVr (OR 2.0,95% CI 1.8–2.2, p<0.001) than in MitraClip. In terms of complications, MitraClip was associated with a higher rate of vascular complications (OR 4.2; 95% CI 1.4–12.8, p<0.001); while both sMVR and sMVr had higher association with significant post-operative bleeding (OR 2.3; 95% CI 1.9–2.8, p<0.001) and (OR 2.1; 95% CI 1.9–2.4, p<0.001) respectively. Conclusion Majority of patients in this cohort with severe MR and CS were treated either medically or underwent surgical MV replacement. Although MitraClip improved hospital mortality over medical therapy, it was associated with a higher mortality risk, readmission rate, and cost of hospitalization when compared to sMVR and sMVr. Funding Acknowledgement Type of funding sources: None.