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

Objective: 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. Methods: 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. Results: 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. Conclusions: 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.