Septal Myectomy and Subvalvular Repair in Hypertrophic Cardiomyopathy, a Systematic Review and Pooled Analysis

Background: Some patients with hypertrophic obstructive cardiomyopathy (HOCM) still exhibit systolic anterior motion (SAM) and mitral regurgitation (MR) even after undergoing an isolated ventricular septectomy. Currently, there are disputes regarding whether to perform a mitral valve intervention and which type of operation is more effective. Methods: By searching PubMed, Cochrane, Embase, Web of Science, FDA.gov, and ClinicalTrials.gov, as well as other resource databases, we obtained all articles published before December 2022 on ventricular septal myectomy combined with mitral valve intervention for hypertrophic cardiomyopathy. Demographic information and outcome variable data were extracted from 10 screened studies on ventricular septal resection combined with mitral valve repair. The risk of bias was assessed using methodological index for non-randomized studies (MINORS). Student's t-test was used for comparisons of continuous variables, and the chi-square or Fisher's exact test was used for dichotomous variables. A total of 692 patients across 10 studies were analyzed. Results: There were 5 (0.7%) deaths in the perioperative period. The average cardiopulmonary bypass time was 64.7 +/- 22.2 minutes, and the average follow-up time was 39.6 +/-+/- 36.3 months. Compared with baseline levels, the left ventricular outflow tract gradient (83.6 +/- 32.2 mmHg vs. 11.0 +/- 7.8 mmHg, p < 0.01), maximum interventricular septal thickness (22.5 +/- 5.1 mm vs. 14.7 +/- 5.5 mm, p < 0.01), III/IV mitral regurgitation (351/692 vs. 17/675, p < 0.01), anterior mitral leaflet (AML)-annulus ratio (0.49 +/- 0.14 vs. 0.60 +/- 0.12, p < 0.01), tenting area (2.72 +/- 0.60 cm(2) vs. 1.95 +/- 0.60 cm(2), p < 0.01), and SAM (181/194 vs. 11/215, p < 0.01) were significantly improved. 14 (2.1%) patients were in New York Heart Association functional class III/IV, which was significantly improved compared with the preoperative state (541/692 vs. 14/682, p < 0.01). Conclusions: Ventricular septectomy combined with mitral valve repair can be a safe and effective treatment option for patients suffering from HOCM with SAM and severe MR.