Apical myectomy: A new surgical technique for management of severely symptomatic patients with apical hypertrophic cardiomyopathy
Read at the Eighty-ninth Annual Meeting of The American Association for Thoracic Surgery, Boston, Mass, May 9–13, 2009.
Received 8 May 2009; received in revised form 10 June 2009; accepted 5 July 2009.
Objective
Apical hypertrophic cardiomyopathy is a morphologic variant in which the hypertrophy is primarily localized to the apex of the left ventricle. A subset of patients have progressive, drug-refractory diastolic heart failure with severely limiting symptoms caused by low cardiac output. Heart transplantation has been the only therapeutic option available for such patients. This study analyzes clinical and hemodynamic outcomes of a novel surgical technique to improve diastolic filling by means of left ventricular cavity enlargement.
Methods
Forty-four symptomatic patients underwent apical myectomy to augment left ventricular end-diastolic volume. Myectomy was performed through an apical incision, and hypertrophic muscle was excised at the apex and midventricle. Information from a prospective database was supplemented by surveys, patient contact, and medical records.
Results
The mean age of the patients was 50 ± 17 years, and 66% were women. All patients were severely limited with dyspnea, 61% had angina, and 59% had syncope/presyncope. Ninety-one percent of patients were in New York Heart Association class III or IV. A mean of 16 ± 7 g of muscle was removed. Preoperative and postoperative hemodynamic catheterization (n = 14) showed a decrease in left ventricular end-diastolic pressure from 28 ± 9 to 24 ± 7 mm Hg (P = .002) and an increase in end-diastolic volume index from 55 ± 17 to 68 ± 18 mL/m2 (P = .003). Invasive measurements of stroke volume increased from 56 ± 17 to 63 ± 19 mL (P = .007). Of the 42 patients who survived to hospital discharge, 41 had improvement in symptoms. Mean peak maximum oxygen consumption with exercise (n = 5) increased from 13.5 ± 4.4 to 15.8 ± 4.6 mL/kg per minute. Survival at 1, 3, and 5 years was 95%, 81%, and 81%, respectively. At follow-up of 2.6 ± 3.1 years, 23 (74%) patients were in New York Heart Association class I or II. One patient underwent heart transplantation 5 years after apical myectomy.
Conclusions
Apical myectomy improves functional status by decreasing left ventricular end-diastolic pressure, improving operative compliance, and increasing stroke volume. This procedure might be of value in other patients with hypertrophic cardiomyopathy who have severe hypertrophy and small left ventricular end-diastolic volume.
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