Septal Myectomy in Hypertrophic Obstructive Cardiomyopathy: Late Results With Stress Echocardiography

Background. This study was performed to assess the functional capacity of the survivors of septal myectomy for the treatment of hypertrophic obstructive cardiomyopathy in long-term follow-up as assessed by dobutamine stress echocardiography. Methods. Sixty-nine patients with hypertrophic obstructive cardiomyopathy underwent septal myectomy between 1975 and 1996. The mean age was 25.4 ± 13.6 years (range, 6–58 years), and 10 of the patients were women. The early mortality was 4.3%. Hospital survivors (95.7%) were followed up for a mean of 43.8 ± 28.7 months (range, 6–114 months). Results. The postoperative mean functional capacity of the group was 1.47 ± 0.56. No late deaths were reported. Forty-nine patients (74.2%) were evaluated with standard echocardiographic techniques, and 29 (43.9%) patients underwent dobutamine stress echocardiography. There was a significant decrease in the thickness of the interventricular septum after surgery. The mean preoperative and postoperative septal thickness was 1.99 ± 0.59 cm (range, 1.3–3.8 cm) and 1.55 ± 0.41 cm (range, 0.96–2.8 cm), respectively (p < 0.004). The mean posterior wall thickness was significantly less than the preoperative value (p = 0.008) and the left ventricular end-diastolic diameter was slightly greater in the postoperative measurements, but the difference was not significant (p = 0.162). Postoperative left ventricular outflow systolic gradients were reduced significantly when compared with preoperative values (preoperative mean, 78.4 ± 33.6 mm Hg, range, 50–212 mm Hg versus postoperative mean, 17.9 ± 15.9 mm Hg; range, 0–40 mm Hg; p < 0.0001). Conclusion. Septal myectomy for patients with hypertrophic obstructive cardiomyopathy is a safe procedure with excellent clinical and functional results in the long-term follow-up.