Author + information
- Jolanda Kluin, MD, PhD∗ (, )
- Arthur A.M. Wilde, MD, PhD,
- Yigal Pinto, MD, PhD and
- Lex A. van Herwerden, MD, PhD
- ↵∗Department of Cardiothoracic Surgery, Academic Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, the Netherlands
In the largest single-center experience of surgical treatment for hypertrophic obstructive cardiomyopathy (HOCM), Hong et al. (1) describe the results of 174 HOCM patients in whom myectomy was combined with mitral valve surgery (MVS). In the same period, an additional 1,819 HOCM patients underwent myectomy alone as this was the preferred surgical strategy of the authors. Mitral valve surgery was indicated because of pre- or perioperatively diagnosed intrinsic mitral valve disease or in a very small percentage of patients because redundant leaflet was thought to contribute to left ventricular outflow tract obstruction.
The authors must be congratulated for their outstanding long-term results in these patients after myectomy plus MVS. More precisely, in these patients they achieved a survival rate that was similar to that of the age- and sex-matched general U.S. population.
To our surprise, this remarkably good result was not the conclusion of the paper. Instead, the authors unexpectedly concluded that “In most patients with HOCM, mitral regurgitation related to systolic anterior motion of the mitral valve is relieved through adequate myectomy. Concomitant MVS is rarely necessary unless intrinsic mitral valve disease is present” (2).
This statement is based solely on the observation that, after isolated myectomy (in 1,819 patients), mitral valve regurgitation (MR) grade ≥3 decreased from 54.3% pre-operatively to 1.7% at transthoracic echocardiography obtained before discharge.
In our opinion, unless data are presented that show that the survival of HOCM patients after isolated myectomy is similar to that of the general population, this conclusion cannot be drawn and is not based on the data presented. In fact, from the data one could conclude that myectomy plus MVS is so effective in the long-term (even in the more difficult HOCM patients) that myectomy should (almost) always be combined with MVS to achieve good relief of left ventricular outflow tract obstruction and thus survival. Indeed, it is our practice to add anterior leaflet extension not to specifically treat systolic anterior motion but to maximally relieve left ventricular outflow tract obstruction (2). Using this technique in 98 HOCM patients, we have reported long-term relief of symptoms and survival similar to the those of the general population (3).
Additionally, we believe that MR grade <3 at discharge echo does not prove that systolic anterior motion will not appear during exercise nor that there is good relief of left ventricular outflow tract obstruction (remember that almost one-half of the patients had MR grade <3 pre-operatively). Data should at least include the gradient over the left ventricular outflow tract and grade of mitral regurgitation during exercise echocardiography at long-term follow-up.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2017 American College of Cardiology Foundation
- Hong J.H.,
- Schaff H.V.,
- Nishimura R.A.,
- et al.
- Van der Lee C.,
- Kofflard M.J.M.,
- Van Herwerden L.A.,
- Vletter W.B.,
- Ten Cate F.J.