Defining the prognosis of chronic total occlusions during primary percutaneous coronary intervention

BACKGROUNDThe influence of coexisting collateral circulation between chronic total occlusion (CTO) and infarct-related artery (IRA) in patients with acute ST segment elevation myocardial infarction (STEMI) remains unclear. We aimed to investigate the impact of coexisting collateral circulation between CTO and IRA on early clinical outcomes in patients with acute STEMI. METHODSA total of 1488 consecutive acute STEMI patients who underwent primary percutaneous coronary intervention were prospectively included in the study. After restoration of antegrade flow, the patients who had coexisting CTO and collateral supply from IRA were defined as the CTO–IRA-related (CIR) group (n=56). Patients with coexisting CTO but with no collateral supply from IRA were defined as the CTO–IRA-unrelated (CIUR) group (n=104). Patients without coexisting CTO were defined as the non-CTO group (n=1328). RESULTSCompared with the CIUR and non-CTO groups, the CIR group was significantly associated with higher Killip class of at least 2 (P