Author + information
- Barry J. Maron, MD∗ (, )
- Joseph A. Dearani, MD,
- Steve R. Ommen, MD,
- Martin S. Maron, MD,
- Hartzell V. Schaff, MD,
- Rick A. Nishimura, MD,
- Anthony Ralph-Edwards, MD,
- Harry Rakowski, MD,
- Mark V. Sherrid, MD,
- Daniel G. Swistel, MD,
- Sandhya Balaram, MD,
- Hassan Rastegar, MD,
- Ethan J. Rowin, MD,
- Nicholas G. Smedira, MD,
- Bruce W. Lytle, MD,
- Milind Y. Desai, MD and
- Harry M. Lever, MD
- ↵∗Minneapolis Heart Institute Foundation, 920 East 28th Street, Suite 620, Minneapolis, Minnesota 55407
Treatment of progressive heart failure, due to left ventricular (LV) outflow tract obstruction and elevated intraventricular systolic pressures, has been a major component of hypertrophic cardiomyopathy (HCM) disease management for 50 years (1–3). Throughout this time, septal myectomy has been the primary treatment option to abolish outflow gradients, normalize LV pressures, and relieve severe heart failure symptoms refractory to maximal medical management (1,2).
The role of myectomy in the HCM treatment armamentarium has depended not only on its effectiveness for relieving heart failure symptoms, but also its safety with acceptable operative risk. Before 1990, experience with myectomy was relatively limited and the mortality rate relatively high (i.e., up to 8% in the largest series from the National Institutes of Health) (2).
Contemporary mortality data for myectomy are well known to experts in dedicated HCM centers but may not have penetrated sufficiently into the practicing general cardiology community. Therefore, this is an opportune time to tabulate the most recent operative mortality data from 5 major high-volume HCM myectomy centers in North America (Table 1). Over the most recent 15-year period, almost 3,700 isolated myectomy operations were performed at these institutions, with a composite operative mortality (first 30 days) of only 0.4% (Table 1).
Operative deaths were at ages 24 to 82 years (mean 62; 6 [35%] ≥70 years); 44% were men. Only 6 of the 17 deaths (35%) occurred after 2010. Notably, 2 of the 4 deaths in 1 series were in patients with prior alcohol septal ablation; surgical myectomy performed after ablation is associated with higher risk (2).
These data establish septal myectomy, when performed in experienced HCM centers, to be one of the safest open-heart procedures currently practiced (i.e., risk significantly lower than that for coronary artery bypass grafting [2.3%], valve replacement [3.4%; 5.7% for the mitral valve], and mitral valve repair [1.6%]) (3) and similar to that of atrial or ventricular septal defect closure. Also, myectomy is associated with similar (if not lower) mortality than percutaneous alcohol ablation (4).
Of particular note, post-operative mortality in experienced HCM myectomy centers is 15-fold less than that recently reported by Panaich et al. (5) (i.e., 5.9%) from U.S. “real-world” community hospital or low-volume surgical settings. Morbidity and mortality appeared to be related largely to iatrogenic complete heart block from muscular resection in the area of the atrioventricular conduction tissue (rate 9%).
Contemporary mortality data for myectomy are a source of reassurance to many patients with HCM, contributing to the increasing numbers of symptomatic patients selecting surgery over alcohol ablation. The striking decrease in operative risk over the past 25 years is attributable to acquired surgical experience, improved intraoperative myocardial preservation, and shorter cardiopulmonary bypass times.
As underscored by guideline expert consensus panels (1,2), septal myectomy is preferably performed in high-volume tertiary centers staffed by skilled surgeons experienced with the complex LV outflow tract anatomy in HCM (1,2), rather than in low-volume institutions in which this operation is rarely performed. Higher patient volume and more experience equates to lower operative risk.
Based on data in almost 3,700 consecutive severely symptomatic patients with obstructive HCM, myectomy performed in dedicated HCM centers with experienced surgeons and staff is one of the safest open-heart procedures, with mortality rates as low as 0.3%. Indeed, perceptions of HCM and myectomy have been contaminated by older obsolete published reports skewed to a grim portrayal of outcome, including high operative mortality (1,2). Therefore, a contemporary understanding of the safety (and efficacy) (1,2) attributable to myectomy is crucial to assessing the role of surgery in the management armamentarium for this disease.
The large mortality discrepancy between community hospitals and HCM centers underscores that surgical myectomy should be considered a specialized operation best performed in high-volume HCM institutions. Promotion of dedicated HCM centers (1) is a strategy that will undoubtedly increase the number of surgeons with myectomy experience and assure patients future accessibility to this important operation and its benefits.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
- Maron B.J.,
- Ommen S.R.,
- Semsarian C.,
- et al.
- Gersh B.J.,
- Maron B.J.,
- Bonow R.O.,
- et al.