Validation of Risk Calculator for Surgical Repair of Primary Mitral Regurgitation in a Minimally Invasive Mitral Valve Surgery Cohort

Background: Risk estimation for cardiac procedures is essential in clinical decision-making. However, a dedicated risk prediction tool for mitral valve surgery including etiology and access is still lacking. The aim of the study is to validate the recently published risk scoring model for surgically treated patients with primary mitral valve disease, investigating a large cohort of patients undergoing minimally invasive mitral valve repair (MI-MVr).

Methods: 1,081 consecutive patients with primary mitral regurgitation (MR) (Carpentier type II MV pathology) undergoing non-emergent MI-MVr were included in the study. The primary study endpoint was all-cause 30-day mortality. Secondary endpoints were hospital mortality and morbidity including stroke, renal failure, cardiac re-operation, prolonged mechanical ventilation (>24 hour), and postoperative mediastinitis. Risk scores were calculated online using the official Web sites and calculators (EuroSCORE II, STS score, Risk Calculator for Surgical Repair of Primary Mitral Regurgitation). Predictive discrimination of the Intent-to-Treat Mortality and M and M (Mortality and Morbidity) model were measured using ROC analysis (area under the curve [AUC]).

Results: A 30-day mortality of 0.56% was observed in the study cohort. Similar discrimination in terms of 30-day mortality was observed between the ITT-Mortality model and Euroscore II and STS-Prom (AUC = 0.729; 0.740 and 0.714, respectively). ITT-Mortality model was observed to be more predictive in terms of observed/expected mortality rates (see Fig. 1). Predictive performance of ITT-M&M models was evaluated for postoperative mortality and morbidity based on the ROC analysis (AUC = 0.636, p < 0.001). The risk of mortality and morbidity is lower in patients without concomitant procedures (with mean risk of 5.82%) than in those with concomitant procedures (mean risk of 9.99%) (p < 0.001).

Table 1

Observed-to-expected ratio		P-value
Euroscore II	0.46	<0.001
STS-Prom score	0.70	<0.001
ITT-Mortality	0.72

Conclusion: This large single-center study validated similar discrimination in terms of 30-day mortality between the recently proposed model and existing models. This is the first report validating the recently published risk scoring model for mitral valve repair in primary MR.

Publication History

Article published online:
11 February 2025