Mid-term results of the floating stitch for systolic anterior motion in hypertrophic obstructive cardiomyopathy

Systolic anterior motion (SAM) is an important factor for hypertrophic obstructive cardiomyopathy (HOCM) patients with a hypertrophic interventricular septum. We developed the 'floating stitch technique' to relieve SAM and have used it since 2017. The mid-term results of the floating stitch technique are reported.

Ten consecutive HOCM patients (5 male, mean age 65.6 years) who underwent septal myectomy and the floating stitch technique from 2017 to 2022 were included. All patients underwent preoperative, pre-discharge, and annual follow-up echocardiographic evaluations. The median postoperative observation period was 3.5 (range 1.2-6.6) years.

There were no cases of cutting or elongation of the floating stitch during the follow-up period. The median mitral valve area (MVA) was 2.9 [interquartile range (IQR) 2.6-3.1] cm² before surgery, 2.6 (IQR 2.2-2.7) cm² before discharge, and 2.6 (IQR 2.2-2.8) cm² at the latest follow-up. There were no cases of mitral stenosis clinically. All cases showed a significant decrease in the left ventricular outflow tract pressure gradient after surgery, but one case required re-operation due to recurrent obstruction at the mid-cardiac position. SAM did not recur in any cases, and all patients were in NYHA class 1 at the latest follow-up.

The floating stitch technique showed an excellent SAM-suppression effect and durability. MVA decreased about 10% following the floating stitch technique, but sufficient area was secured without functional mitral stenosis. The combination of septal myectomy and floating stitch technique is a simple and reproducible procedure for HOCM, especially with severe SAM.