Septal Myectomy With Vs Without Subvalvular Apparatus Intervention in Patients With Hypertrophic Obstructive Cardiomyopathy: A Prospective Randomized Study.

Surgical septal myectomy is a standard treatment option for patients with hypertrophic obstructive cardiomyopathy. Subvalvular abnormalities of the mitral valve might play an important role in residual left ventricular outflow tract obstruction. This randomized study aimed to compare the surgical outcomes of septal myectomy with vs without subvalvular interventions. Between July 2015 and December 2016, 80 eligible patients were randomly assigned to undergo septal myectomy with vs without subvalvular intervention. The peak gradient was 92.3 ± 16.9 and 88.1 ± 15.4 mm Hg, respectively (P = 0.281). The mean septum thickness was 26.8 ± 4.5 and 26.1 ± 4.2 mm, respectively (P = 0.504). Moderate or severe systolic anterior motion syndrome-mediated mitral regurgitation was observed in all patients. There was no residual mitral regurgitation in the group with subvalvular intervention, while 15% of patients in the control group had regurgitation (P = 0.013). Residual systolic anterior motion syndrome was observed in 5% and 27.5% of patients, respectively (P = 0.007). The median postoperative gradient was 13 (interquartile range 9-16) mm Hg and 8 (interquartile range 4-12) mm Hg, respectively (P = 0. 0.019). At the 12-month follow-up, all patients were alive. There were 87.5% vs 77.5%, and 12.5% vs 22.5% of patients categorized as having New York Heart Association functional classes I and II, respectively (P = 0.378). The prevalence rate of residual mitral regurgitation was 10% and 32.5%, respectively (P = 0.010). Concomitant subvalvular intervention during septal myectomy more effectively eliminates left ventricular outflow tract obstruction, providing better freedom from residual mitral regurgitation without clinical benefit 1 year after surgery.

Myectomy with mitral valve repair versus replacement in adult patients with hypertrophic obstructive cardiomyopathy: a systematic review and meta-analysis.

We evaluated the differences in mitral valve (MV) plasty (MVP) and MV replacement (MVR) with respect to death, postoperative MV dysfunction, reoperation rates and thromboembolic events (DFRE) in patients with hypertrophic obstructive cardiomyopathy and systolic anterior motion of the anterior mitral leaflet-mediated MV regurgitation (HOCM & MR). We followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, searching PubMed, Cochrane library and ClinicalTrials.gov for studies that evaluated DFRE in adults with HOCM & MR after MVP/MVR. We used a risk of bias assessment tool for non-randomized studies, and analyses were performed using Cochrane Review Manager 5.3.5 for I2 statistics, funnel plots and forest plot and the generic inverse variance method for hazard ratios (HRs). We developed qualitative and quantitative syntheses of 35 and 23 studies, respectively, including levels of evidence of ½/3/4/5 = 3/1/11/11/9 and ½/3/4/5 = 0/1/11/11/0, respectively, from January 1980 to August 2017. A statistically significant difference between MVP and MVR favoured MVP for the prevention of DFRE in patients with HOCM & MR, on the basis of a significant reduction of the HR for DFRE: HR = 0.68 (0.57, 0.82), I2 = 68% (P = 0.002). The findings were as follows: (i) MVP should be the first-line treatment in patients with HOCM & MR (accuracy LEVEL A) and (ii) MVR may be harmful if it is used as the first-line treatment (accuracy LEVEL A).