Long-term results after myectomy in 64 patients with hypertrophic obstructive cardiomyopathy (HOCM) - Morphological and hemodynamic aspects

Background. The aim of this study was to observe the changes in left-ventri cular morphology, the improvement in hemodynamics and the survival curves ( according to Kaplan-Meier) of patients following transaortic myectomy. Methods. From November 1985 to August 1997, transaortic myectomy according to Morrow's proposal was carried out at the Heart Center NRW in Bad Oeynhau sen in 64 patients with isolated HOCM, At the time of operation, the patien t group included 33 women and 31 men aged between 14 and 76 years (mean 52. 56 years). A hemodynamically relevant aortic stenosis was excluded in all p atients, Sixty-three patients (98.4%) were evaluated in total over a mean o bservation period of 4.6 years (4 months to 12 years). One patient lost tou ch with our hospital Results, The clinical symptoms according to NYHA grade could be improved po stoperatively from 3.4+/-0.33 to 1.36+/-0.6 (p<0.001). The echocardiographi c preoperative pressure gradient between the left ventricle and the aorta w as 73.2+/-14.8 mmHg at rest and 139.6+/-21.2 mmHg after provocation by vent ricular premature beats (VPBs). Postoperatively, the gradient was reduced s ignificantly: 13.56+/-2.7 mmHg at rest and 23.3+/-10.7 mmHg after VPBs, res pectively (p<0.001). Perioperative complications occurred in 12 patients in cluding 1 early death due to low-output syndrome, corresponding to an early mortality rate of 1.6%. Four patients died within a postoperative period o f 1 year to 9.5 years, none of them due to cardiac causes, 2 due to non-car diac causes and 1 of unknown causes. In 2 patients a recurrent HOCM occurre d at 7 and 10 years after the myectomy and they were treated by catheter in tervention with the alcohol induced septal infarction. Conclusions. Based on the 12-year survival tate of 76.64% in our study, tra nsaortal myectomy according to Morrow represents a safe and reliable form o f therapy, with relatively low perioperative mortality and complication rat es, also in the long-term.