Early infarct artery collateral flow does not improve long-term survival following thrombolytic therapy for acute myocardial infarction

It is known that acutely developed collateral can prevent the onset of acut e myocardial infarction (AMI) in the presence of a total coronary occlusion . However, there still is controversy concerning long-term follow-up of cor onary collateral circulation to the infarct-related artery. In this study w e analyze the prognostic role of collateral flow (degrees 0 to 3) as well a s anterograde flow (degrees 0 to 3) in patients with AMI treated with throm bolytic therapy. Four hundred twenty-two patients (median age 57 years, 355 men) with AMI were treated with intravenous streptokinase and followed pro spectively for up to 8 years. At the end of the study period, patients with collateral coronary flow 3 (n = 30) and those with flow <3 (n = 392) at in -hospital coronary arteriography had survival rates of 66% and 85%, respect ively (p <0.12). Meanwhile, patients with coronary anterograde flow 3 (n = 189) and those with flow <3 (n = 233) had survival rates of 89% and 80%, re spectively (p <0.04). By censored regression analysis, a negative correlati on was found between coronary collateral flow degree and survival (p = 0.04 98) and, inversely, a positive correlation was found between coronary anter ograde flow degree and survival (p = 0.0053). By Cox multivariate analysis, the following variables showed significant correlations with long-term sur vival: global left ventricular ejection fraction (p = 0.0003), anterograde flow degree (p = 0.0006), collateral flow degree (negative correlation, p = 0.0179), and medical treatment (negative correlation, p = 0.0464). Thus, p atients treated with intravenous streptokinase during AMI and with adequate coronary collateral circulation had a worse prognosis than those who devel oped adequate anterograde flaw, probably because of residual myocardial isc hemia. Such patients may benefit from coronary revascularization (angioplas ty or surgery) to restore anterograde brood flow and minimize myocardium at risk. (C)1999 by Excerpta Medica, Inc.