Long-Term Performance of Epimyocardial Pacing Leads in Adults: Comparison with Endocardial Leads

It has been shown that coronary excimer laser angioplasty can remove atherosclerotic intracoronary tissue. Stand alone coronary excimer laser angioplasty was successfully performed in a 53 year old white man with 90% stenosis of the left anterior descending coronary artery and exertional angina (Canadian Cardiovascular Society class III). The lesion was reduced to a 30% residual stenosis with use of a 1.2 mm and subsequently a 1.8 mm diameter laser catheter. Early follow-up angiography 24 h later revealed persistent patency and unchanged lesion diameter of the target vessel. The patient was free of symptoms during the 2 month follow-up period, but died suddenly while playing in a tennis tournament 63 days after the procedure. Postmortem histologic examination revealed 80% restenosis at the lesion site without plaque disruption or thrombosis. Specific staining of the histologic specimen for smooth muscle cells using alpha-actin revealed significant smooth muscle cell proliferation at the site of coronary excimer laser angioplasty. However, most of the vessel narrowing appeared to be due to underlying fibrotic plaque as a result of insufficient tissue ablation. This was probably related to the size of the currently available catheters, which are too small to create a large channel.