ABSTRACT
In the first 6 months of RESEARCH, 56 patients were successfully revascularized for at least one CTO with sirolimus-eluting stents and were compared with 28 patients treated with bare stents in the period before. Chronic total occlusion was defined as a complete occlusion on angiography, with no antegrade filling of the distal vessel other than via collaterals. All included patients had a native vessel occlusion estimated to be of at least 1-month duration,123 based on either a history of sudden chest pain, a previous acute myocardial infarction in the same target vessel territory, or the time between the diagnosis made on coronary angiography and PCI. The length of the occlusion was measured by quantitative coronary angiography either by utilizing antegrade filling via collaterals, or by assessment of the retrograde collateral filling. For this, it was frequently performed a double catheterization of both the left and right coronary arteries, with simultaneous contrast injection to delineate the distance between the site of occlusion and the most proximal part of the vessel filled retrogradely.
