The short- and long-term outcome of left internal mammary artery angioplasty

Failure of internal mammary artery (IMA) bypass grafts is uncommon. However, as their use continues to increase, this complication will be encountered more frequently by interventional cardiologists. The purpose of this article is to describe the short-and long-term outcome of patients undergoing IMA angioplasty through a retrospective review of patients undergoing internal mammary angioplasty at two centers from January 1988 to June 1995. Percutaneous recanalization was attempted on 82 lesions either within an IMA or in the ongoing native left anterior descending artery during 74 procedures in 67 patients. The mean time from bypass surgery was 23 months. The lesion success rate was 84%. Dissection of the IMA occurred in 18% of procedures and was the most common cause for procedural failure and unfavorable outcome. Long-term follow-up was available in 82% of patients at a mean follow-up of 45 months postprocedure. Clinical events occurred in 23 patients (34%) with 4 deaths (1 of which occurred during the initial hospitalization and after emergency bypass surgery), 2 repeat coronary bypass operations, and 17 patients with repeat coronary angioplasties. Despite the high repeat revascularization rate, 80% of patients were asymptomatic or had only infrequent angina at follow-lip. We conclude that angioplasty of or through an IMA bypass graft can be performed with a satisfactory procedural success rate and long-term symptomatic benefit.