Early post-septal myectomy outcomes for hypertrophic obstructive cardiomyopathy.

BACKGROUND: We aimed to evaluate early outcomes of septal myectomy in patients with hypertrophic cardiomyopathy. METHODS: We retrospectively analyzed data collected over a 9-year period from 583 patients who underwent septal myectomy for hypertrophic cardiomyopathy at our institution. RESULTS: The mean age was 55.7 ± 13.1 years, and 338 (58%) patients were in New York Heart Association class III or IV. There were 11 (1.9%) early deaths, including 3 (0.5%) intraoperative deaths. Early mortality was lowest after isolated septal myectomy (0.8%) and highest after concomitant mitral valve replacement (6.1%). There were 4 (0.7%) and 9 (1.5%) patients with left ventricular wall rupture and ventricular septal defect, respectively, after myectomy. New pacemaker implantation caused by atrioventricular disturbances was required in 29 (5.0%) patients, and was associated with previous alcohol septal ablation (odds ratio 3.34, 95% confidence interval 1.02-11.0, P = 0.047). Left ventricular wall rupture, intraoperative residual (15.5% moderate, 0.3% severe) mitral regurgitation, and pre-discharge residual outflow tract gradient >30 mm Hg (4.6%) occurrences were surgeon-dependent. CONCLUSIONS: The early results are consistent with example targets reported in the 2020 American College of Cardiology/American Heart Association guidelines for septal reduction therapy outcomes. Septal myectomy safety and efficacy are surgeon-dependent. Previous alcohol septal ablation increases the risk of permanent pacemaker implantation due to postoperative complete atrioventricular block. Therefore, continuous education, mentoring, and learning by doing may play an important role in achieving reasonable septal myectomy safety and efficacy.

Surgical Atrial Fibrillation Ablation With and Without Left Atrium Reduction for Patients Scheduled for Mitral Valve Surgery: A Prospective Randomised Study.

BACKGROUND: The influence of left atrium (LA) enlargement on atrial arrhythmia recurrence (AAR) after surgical ablation in patients with mitral valve (MV) disease remains unresolved. OBJECTIVE: Left atrial size is critical to the success of concomitant atrial fibrillation (AF) ablation in patients scheduled for MV surgery. However, a large LA should not be a limiting factor when evaluating surgical candidates with AF if they receive appropriate treatment during concomitant ablation. This randomised study assessed whether adding LA reduction (LAR) to the maze procedure for MV surgery patients can improve freedom from AAR. METHODS: From September 2014 to September 2017, 140 patients were randomly assigned into two groups. The maze group underwent MV surgery with concomitant surgical AF ablation (n=70). The maze + LA reduction group underwent MV surgery with concomitant AF ablation and LA reduction procedure (n=70). Rhythm outcomes were estimated by Holter monitoring, according to Heart Rhythm Society guidelines. RESULTS: The concomitant LA reduction procedure did not increase early mortality and complications rates. Significant differences in freedom from AAR were observed at 24 months (maze, 78.4%; maze + LAR group, 92.3%; p=0.025). A significant difference in LA volume was detected at discharge (p<0.0001); however, it was not significantly different at 24 months (p=0.182). CONCLUSIONS: Adding LA reduction to the maze procedure led to improvements in freedom from AAR for patients with AF and LA enlargement scheduled for MV surgery. A concomitant LA reduction procedure did not increase mortality and perioperative risk.

Single-Centre Experience of Surgical Myectomy for Hypertrophic Obstructive Cardiomyopathy.

BACKGROUND: Septal myectomy is the gold standard treatment for hypertrophic obstructive cardiomyopathy. This study aimed to evaluate the results from patients with hypertrophic cardiomyopathy who had undergone septal myectomy. METHODS: Data were analysed that has been prospectively collected over 7 years from 345 patients with hypertrophic cardiomyopathy who underwent septal myectomy at Meshalkin National Medical Research Center. RESULTS: Six (6) patients (1.7%) died within 30 days of surgery. The mean (standard deviation, SD) resting left ventricular outflow tract gradients reduced from 83.4 (24.2) mmHg preoperatively to 16.2 (8.5) mmHg at discharge (p < 0.001). Of the 345 patients, 329 (95.4%) attended the most recent follow-up assessments, and of these, 254 (77.2%) were categorised as New York Heart Association (NYHA) class I, 64 (19.5%) class II, and 11 (3.3%) class III. The mean overall long-term survival rate after septal myectomy was 95.7% (SD 1.7%) (95% CI, 90.0-97.9). This did not differ from the age-matched and gender-matched general population (log-rank, p = 0.109). At the last follow-up assessments, six of 67 patients who had undergone concomitant Cox-Maze IV procedures had late atrial tachyarrhythmia recurrences. A preoperative short-axis view of left atrial diameter of 57.5 mm (hazard ratio, 1.30 (95% CI, 1.03-1.65), p < 0.001) predicted late atrial tachyarrhythmias (p < 0.002). CONCLUSIONS: At this hypertrophic cardiomyopathy centre, septal myectomy is associated with low operative and early mortality rates (<2%), a low risk of early adverse events, and acceptable intermediate-term clinical and haemodynamic results.