Septal Myectomy in patients with previous coronary revascularization - hypertrophic cardiomyopathy masquerading as ischemic heart disease.

BACKGROUND

Patients with obstructive hypertrophic cardiomyopathy (HCM) may have symptoms mimicking ischemic heart disease, including chest pain and shortness of breath. Some patients undergo coronary revascularization which may not lead to symptomatic improvement. This study assesses clinical presentations and outcomes of patients with previous coronary revascularization undergoing septal myectomy.

METHOD

From 08/1996 to 07/2017, 166 adult patients with obstructive HCM underwent septal myectomy at our Clinic with a history of percutaneous coronary intervention (PCI, N = 153) or coronary artery bypass grafting (CABG, N = 13). We assessed their functional status before and after coronary intervention and outcomes following myectomy.

RESULTS

The median (IQR) age was 65 (59-71) years, and 106 (64%) were male. Among 150 patients whose extent of disease was known, single vessel disease was identified in 109 (73%) who had PCI and 1 (9%) who had CABG. Following revascularization, many (59%) reported no improvement in shortness of breath from preoperative status. Myectomy was performed at a median of 3.2 (1.0-6.3) years following coronary revascularization, and 40 (25%) required myectomy within 1 year. Patients whose shortness of breath persisted after PCI/CABG (N = 90) underwent myectomy earlier than those whose symptoms initially improved (N = 63) after coronary revascularization (1.4 [0.6-4.0] years vs. 5.1 [2.8-9.5] years, p < .001).

CONCLUSION

Almost 25% of patient's required septal myectomy within 1 year of coronary intervention for continued symptoms originally thought to be due to ischemic heart disease. These findings highlight the overlap of obstruction and ischemic symptoms and the importance of complete evaluation for dynamic obstruction in HCM.