Comparison of clinical outcomes between sufficient versus insufficient diagonal branch flow in anterior acute myocardial infarction.

In primary percutaneous coronary intervention (PCI), revascularization to the main branch is considered to be more important than that to the side branch. The purpose of the present study was to compare in-hospital clinical outcomes between sufficient and insufficient diagonal flow in patients with anterior ST-elevation acute myocardial infarction. A total of 229 left anterior descending artery (LAD)-AMI with final Thrombolysis in Myocardial Infarction (TIMI)-3 LAD flow were included, and divided into the sufficient diagonal flow group (TIMI-3 diagonal flow: n = 170) and the insufficient diagonal flow group (TIMI ≤ 2 diagonal flow: n = 59). The primary endpoint was the incidence of mechanical complication. The secondary endpoints were incidences of in-hospital death, heart failure at discharge, and left ventricular thrombus. There were no significant differences in the primary endpoint (the sufficient diagonal flow group: 1.2%, the insufficient diagonal flow group: 0%, P = 0.403). In-hospital death was more frequently observed in the insufficient diagonal flow group (8.5%) than the sufficient diagonal flow group (2.9%) without reaching statistical significance (P = 0.073). The incidence of heart failure at discharge, and thrombus in left ventricular were not different between the two groups. In conclusion, in-hospital outcomes were not significantly different between the sufficient and insufficient diagonal flow groups. We may not stick to the diagonal flow in LAD-STEMI, as long as the LAD flow is maintained by PCI.