Boston - American Association for Thoracic Surgery

AMERICAN ASSOCIATION FOR THORACIC SURGERY8. Apical Myectomy: A New Surgical Technique for the Managementof Severely Symptomatic Patients with Apical HypertrophicCardiomyopathyHartzell V. Schaff, 1* Morgan L. Brown, 1 Steve R. Ommen, 1 Joseph A. Dearani, 1Martin D. Abel, 1 A.J. Tajik, 2 Rick A. Nishimura 11. Mayo Clinic, Rochester, MN, USA; 2. Mayo Clinic, Scottsdale, AZ, USAInvited Discussant: Nicholas G. SmediraOBJECTIVE: Apical hypertrophic cardiomyopathy (ApHCM) is a morphologicvariant in which the hypertrophy is primarily localized to the apex of the leftventricle (LV). A subset of patients develop progressive drug refractory diastolicheart failure with severely limiting symptoms due to a resultant low cardiac output.Heart transplant has been the only therapeutic option available for suchpatients. This study analyzes clinical and hemodynamic outcomes of a novel surgicaltechnique to improve diastolic filling by LV cavity enlargement.MONDAYAfternoonMETHODS: From 1993 through May, 2008, 43 symptomatic patients with ApHCMunderwent apical myectomy to augment LV end-diastolic volume (EDV). Informationfrom a prospective database was supplemented by survey information, patientcontact, and review of medical records.RESULTS: The mean age was 50 ± 17 yr and 65% were female. All patients wereseverely limited with dyspnea, 63% had angina, and 60% had syncope or presyncope.Ninety-one percent of patients were in New York Heart Association(NYHA) class III or IV. Myectomy was performed through an apical incision, andthe LV cavity was augmented by excision of hypertrophic muscle at the apex andmid ventricle; a mean of 16 ± 7 g of muscle was removed. In 14 patients who underwentpre- and postoperative hemodynamic catheterization, the LV end-diastolicpressure decreased from 28 ± 9 to 24 ± 7 mmHg (P = 0.002) and the EDV indexincreased from 55 ± 17 to 68 ± 18 cc/m 2 (P = 0.003). Invasive measurements ofstroke volume increased from of 56 ± 17 cc to 63 ± 19 cc (p = 0.007). Forty of fortyonehospital survivors had improvement in symptoms after operation. The meanpeak maximum oxygen consumption on exercise testing (n = 5) increased from13.5 ± 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 an average follow-up of 2.6 ± 3.1 years, 23 patients(74%) were in NYHA class I or II. One patient underwent heart transplant 5 yearsafter apical myectomy.CONCLUSION: For patients with ApHCM who have limiting symptoms despiteoptimal medical treatment, apical myectomy can improve functional status bydecreasing LV end-diastolic pressure, thus improving the effective operative complianceof the LV and increasing stroke volume. This procedure may be of value inother patients with HCM who have severe hypertrophy and small LV end-diastolicvolumes.* AATS Member83