Predictors of long‐term outcome after septal myectomy in symptomatic hypertrophic obstructive cardiomyopathy patients with previous alcohol septal ablation and residual obstruction

Abstract

Background and aim Recently alcohol septal ablation (ASA) has emerged as an alternative treatment for drug‐refractory hypertrophic obstructive cardiomyopathy (HOCM) and a subgroup of HOCM patients with previous ASA may need myectomy. However, subsequent outcome and mechanism of residual obstruction has not been determined. This study aims to determine outcome after myectomy and mechanism of residual obstruction in HOCM patients with previous ASA. Methods From February 2009 to June 2017, 38 HOCM patients with previous ASA underwent surgical septal myectomy at our institution. Seventy‐six patients who underwent surgical septal myectomy initially were included as the comparison group through one‐to‐two propensity score matching method. Results Fourteen available cardiac magnetic resonance images revealed inferior location and small area of infarcted myocardium induced by ASA in 12 patients and outside targeted location in two patients. During follow‐up (median, 2.4; maximum, 7.8 years), event‐free survival at 7 years was 83.2% in the previous ASA group and 94.6% in the comparison group, respectively (P = 0.0378). Multivariable analysis indicated previous ASA (hazard ratio, 4.28; 95% confidence intervals [CI], 1.20‐15.26; P = 0.025) and postoperative left ventricular end‐diastolic diameter (hazard ratio, 1.14; 95% CI, 1.05‐1.23; P = 0.002) were independent predictors of adverse events. Conclusions This study demonstrated that uncontrollable extent and location of infarcted myocardium induced by ASA may attribute to residual obstruction after previous ASA, and the long‐term event‐free survival after myectomy was inferior. It may provide special precaution to patient selection and the increased number of ASA practiced worldwide.

Ventricular Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy (Analysis Spanning 60 Years Of Practice): AJC Expert Panel

“…115 The vast majority of patients incur left bundle branch as a result of the operative resection which does not influence later clinical course. 112 Surgeons performing myectomy after an unsuccessful ASA report less consistent operative results and a higher rate of complete heart block, [116][117][118] underscoring that myectomy is the preferred initial procedure to avoid myocardial scarring, heart block and other potential adverse consequences of ASA.…”

Echocardiographic Predictors of All-Cause Mortality in Patients with Hypertrophic Cardiomyopathy following Pacemaker Implantation

“…Nevertheless, LVEDD was not an independent predictor in the further analysis. Zhu et al [39] enrolled 38 HOCM patients with previous alcohol septal ablation who underwent surgical septal myectomy and found postoperative LVEDD (HR � 1.14; 95% CI � 1.05-1.23; P � 0.002) was an independent predictor of adverse events. Seiler et al [40] indicated that HCM patients with chamber dilatation had a worse prognosis than those without, particularly for the quality of life.…”

Inter-ventricular Septum Ablation for the Treatment of Hypertrophic Obstructive Cardiomyopathy

“…In 1998, the first PTSMA was performed in China. PTSMA has gradually become an important method for the treatment of HOCM in China [13]. However, the injection of absolute ethanol in the wrong location during surgery may cause myocardial necrosis and scar formation, which may lead to severe complications, such as complete heart block, persistent ventricular tachycardia, ventricular fibrillation, cardiac arrest, ventricular septal perforation, and pericardial effusion [14].…”

“…The optimum dose of alcohol injected into the target blood vessel can produce the most appropriate infarct size, so as to achieve the greatest clinical and hemodynamic effects [12]. Zhu et al [13] pointed out that the main reason for residual obstruction after PTSMA may be that degree and location of myocardial infarction caused by PTSMA are not easily controllable. However, compared with long-term event-free survival after ventricular septal resection, PTSMA is generally preferred.…”