Purpose. The cohort randomized study was conducted to establish the effectiveness of surgical extended septal myectomy accompanied by anomalous fibrous chordal attachments resection and papillary muscles (PM) mobilization in symptomatic patients with HOCM and different degrees of HF.
Methods. The research includes 118 consecutive symptomatic patients with HOCM who underwent surgical extended myectomy with anomalous chordal attachments (secondary chordae) resection and mobilization of the anterior and posterior groups of PM. In case of necessity, a plication of the mitral valve leaflet was performed to reduce the length of the oversized structure and thus reduce the risk of post-operative systolic anterior motion (SAM) effect. The following parameters before and after surgical intervention were evaluated: systolic pressure gradient (SPG) on the left ventricle outflow tract (LVOT), mitral regurgitation (MR) degree, NYHA functional class, survival rate and main post-operative complications.
Results. According to the obtained data, SPG on LVOT decreased from 93,6±23,2 mmHg prior the surgery to 19,7±11,4 mmHg after the treatment (p<0,001). 21 (17,8%) patients had moderate degree of MR after the surgery, as before intervention the number of patients having moderate or severe MR degree accounted 101 (85,5%)(p<0,001). Out of 118 patients, 36 (30,5%) of whom have had III-IV NYHA functional class before the procedure, 115 (97,4%) were in functional class I-II at the discharge (p<0,001). No patients with III-IV NYHA functional class were observed. The mortality accounted 1,7% (2 patients). Among 118 patients, one (0,8%) underwent implantable cardioverter-defibrillator (ICD) implantation within sudden cardiac death prophylaxis; 5 (4,2%) patients underwent pacemaker implantation due to complete post-operative AV-block.
Conclusion. Surgical extended septal myectomy remains a gold standard of treatment of patients with HOCM. The presented study showed not only successful results of surgical correction, but most importantly, significant decrease of the HF manifestation in symptomatic patients and improvement of quality of life already in early post-operative period.