Short- and Mid-Term Outcomes after Surgical Myectomy in Patients with Hypertrophic Obstructive Cardiomyopathy

Background: To evaluate short- and mid-term outcomes after transaortic septal myectomy with or without mitral valve (MV) surgery in patients (pts) with hypertrophic obstructive cardiomyopathy (HOCM) and systolic anterior motion (SAM) of MV.

Methods: We retrospectively reviewed all pts who underwent myectomy from January 2011 to July 2018 at our institution. Out of 45 pts who received myectomy for HOCM, 24 pts had additional obstruction of LVOT as well as significant regurgitation of MV due to SAM. This subgroup was evaluated in this study. Pts characteristics, pre- and postoperative echocardiographic findings, as well as New York Heart Association (NYHA) class, perioperative morbidity, and mortality were analyzed. Mean follow-up was 31.6 ± 25.3 months, range 3–82 months.

Results: Mean age of pts was 53 ± 12 years. All pts were highly symptomatic with mean NYHA class 2.5 ± 0.6. Preoperative echocardiography revealed a mean resting gradient of 79 ± 38 and provoked gradient of 109 ± 34 mm Hg. Extensive myectomy as a sole operation was performed in 11 pts (46%). In the remaining pts, concomitant MV procedures were applied. Different surgical techniques were used to repair the MV in eight pts (annuloplasty ring n = 5; modified Alfieri stitch n = 3; implantation of neochordae n = 3; aberrant papillary muscle resection n = 3; leaflet resection n = 1). MV valve replacement with mechanical prosthesis was performed in four pts and with biological prosthesis in one pt.

There was no perioperative mortality. Iatrogenic ventricular septum defect (VSD) occurred in one pt and he received VSD closure with Dacron patch as well as pacemaker implantation at third postoperative day. His further postoperative course was uneventful. Overall, 12.5% of pts received pacemaker implantation during perioperative period. Discharge echocardiography demonstrated reduction of LVOT gradient to 14 ± 9 mm Hg and a mean grade MR of 0.7 ± 0.6. These values remained stable over the years. Mean NYHA class improved to 1.5 ± 0.6 at discharge and was 1.8 ± 0.8 at last follow-up. The freedom from reoperation rate at 5 years was 95.9 ± 1.6%.

Conclusions: Surgical treatment of pts with HOCM is complex and challenging. Nevertheless, in subgroup of pts with HOCM and SAM, extensive myectomy with and without concomitant MV surgery shows excellent relieve of symptoms as well as LVOT gradient and leads to durable reduction of mitral regurgitation.