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Functional significance of coronary collateral perfusion in preserving myocardial integrity

Coronary collateral perfusion to the completely obstructed coronary artery was evaluated by coronary cineangiography in 32 patients. In 13 patients, there was neither history of severe chest pain of longer than 30‐min duration nor electrocardiographic evidence of a transmural myocardial infarction (Group I). Among patients undergoing intracoronary thrombolytic therapy for the completely occluded infarct‐related coronary artery within 6 h after the onset of symptoms of the first acute myocardial infarction, 19 patients had a history of preinfarction angina (Group II). Collateral visualization (collateral index) was found to be significantly greater in Group I (2.5 ± 0.5, SD) than in Group II (0.9 ± 1.0) (p<0.01). Group I patients had a longer history of angina (25 ± 25 months) than did Group II patients (17±18 months) (p=NS). These findings indicate that well‐developed coronary collateral vessels preserve myocardial integrity upon acute coronary occlusion and that a long‐standing angina indicative of myocardial ischemia may play an important role in developing collateral channels.