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.

Edge-to-Edge Repair Versus Secondary Cord Cutting During Septal Myectomy in Patients With Hypertrophic Obstructive Cardiomyopathy: A Pilot Randomised Study.

BACKGROUND: To evaluate whether the Alfieri technique improves clinical and haemodynamic results and compare it with transaortic mitral valve secondary cord cutting in patients scheduled for septal myectomy for severely symptomatic hypertrophic obstructive cardiomyopathy. METHODS: Forty-eight (48) patients with moderate-to-severe systolic anterior motion (SAM)-mediated mitral regurgitation were randomly assigned to the Alfieri or Cutting groups in addition to septal myectomy. The primary endpoint was postoperative mean transmitral pressure gradient (TPG). The secondary endpoints were residual left ventricular outflow tract (LVOT) gradient after procedure, residual mitral regurgitation (MR), postoperative SAM, repeating bypass, and survival. RESULTS: There were no 30-day mortality and ventricular septal defects. The postoperative LVOT gradient was 15.4±7.6 mmHg and 11.1±4.9 mmHg (p=0.078) in the Alfieri and Cutting groups, respectively. The Alfieri technique was associated with higher peak (7.8±3.3 vs 4.7±2.8 mmHg; p=0.014) and mean (3.9±1.7 vs 2.1±1.6 mmHg; p=0.013) TPG. The Cutting group was associated with higher mild MR rate at discharge (six vs no patients; p=0.009). One (1) patient (4.2%) in the Alfieri group required pacemaker implantation owing to conduction disturbances (p=0.312). Two-year (2-year) freedom from late mortality and sudden cardiac death rates were 95.5%±4.4% and 100% for the Alfieri and Cutting groups, respectively (log rank, p=0.317). No patients had New York Heart Association functional class III or IV or moderate or severe MR. The maximum LVOT gradient was 20.4±15.2 mmHg and 16.7±10.4 mmHg, respectively (p=0.330). There were no reoperations during follow-up. CONCLUSIONS: Both techniques with septal myectomy effectively eliminated SAM-induced MR and LVOT obstructions in hypertrophic cardiomyopathy patients.

Myectomy versus alcohol septal ablation in patients with hypertrophic obstructive cardiomyopathy.

OBJECTIVES: There is very little evidence comparing the safety and efficacy of alcohol septal ablation versus septal myectomy for a septal reduction in patients with hypertrophic obstructive cardiomyopathy. This study aimed to compare the immediate and long-term outcomes of these procedures. METHODS: Following propensity score matching, we retrospectively analysed outcomes in 105 patients who underwent myectomy and 105 who underwent septal ablation between 2011 and 2017 at 2 reference centres. RESULTS: The mean age was 51.9 ± 14.3 and 52.2 ± 14.3 years in the myectomy and ablation groups, respectively (P = 0.855), and postoperative left ventricular outflow tract gradients were 13 (10-19) mmHg vs 16 (12-26) mmHg; P = 0.025. The 1-year prevalence of the New York Heart Association class III-IV was higher in the ablation group (none vs 6.4%; P = 0.041). The 5-year overall survival rate [96.8% (86.3-99.3) after myectomy and 93.5% (85.9-97.1) after ablation; P = 0.103] and cumulative incidence of sudden cardiac death [0% and 1.9% (0.5-7.5), respectively P = 0.797] did not differ between the groups. The cumulative reoperation rate within 5 years was lower after myectomy than after ablation [2.0% (0.5-7.6) vs 14.6% (8.6-24.1); P = 0.003]. Ablation was associated with a higher reoperation risk (subdistributional hazard ratio = 5.9; 95% confidence interval 1.3-26.3, P = 0.020). At follow-up, left ventricular outflow tract gradient [16 (11-20) vs 23 (15-59) mmHg; P < 0.001] and prevalence of 2+ mitral regurgitation (1.1% vs 10.6%; P = 0.016) were lower after myectomy than after ablation. CONCLUSIONS: Both procedures improved functional capacity; however, myectomy better-resolved classes III-IV of heart failure. Septal ablation was associated with higher reoperation rates. Myectomy demonstrated benefits in gradient relief and mitral regurgitation elimination. The results suggest that decreasing rates of myectomy procedures need to be investigated and reconsidered.

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.