Evaluation of importance of door-to-balloon time and total ischemic time in acute myocardial infarction with ST-elevation treated with primary percutaneous coronary intervention.

The aim of the study was to evaluate the influence of door-to-balloon time and symptom onset-to-balloon time on the prognosis of patients with acute ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) in the Croatian Primary PCI Network. A total of 1190 acute STEMI patients treated with primary PCI were prospectively investigated in eight centers across Croatia (677 non-transferred, 513 transferred). All patients were divided according to door-to-balloon time in three subgroups (< 90, 90-180, and > 180 minutes) and according to symptom onset-to-balloon time in three subgroups (<180, 180-360, and > 360 minutes). The postprocedural Thrombolysis in Myocardial Infarction flow, in-hospital mortality, and major adverse cardiovascular events (mortality, pectoral angina, restenosis, reinfarction, coronary artery by-pass graft and cerebrovascular accident rate) in six-month follow-up were compared between the subgroups. The Croatian Primary PCI Network ensures results of treatment of acute STEMI comparable with randomized studies and registries abroad. None of the result differences among the door-to-balloon time subgroups was statistically significant. Considering the symptom onset-to-balloon time subgroups, a statistically significant difference at multivariate level was highest for in-hospital mortality in the subgroup of patients with longest onset-to-balloon time (4.5 vs. 2.6 vs. 5.7%; p = 0.04). Door-to-balloon time is one of the metrics of organization quality of primary PCI network and targets for quality improvement, but without an impact on early and six-month follow-up results of treatment for acute STEMI. Symptom onset-to-balloon time is more accurate for this purpose; unfortunately, reduction of the symptom onset-to-balloon time is more complex than reduction of the former.