Clinical manifestations and effects of primary percutaneous coronary intervention for patients with delayed pre-hospital time in acute myocardial infarction

Abstract

Background: Prolonged pre-hospital time for acute myocardial infarction (AMI) is associated with decreased indication for primary percutaneous coronary intervention (PCI). However, the efficacy of primary PCI in AMI patients with prolonged pre-hospital time has not been fully investigated in Japan.

Methods and results: A total of 3010 consecutive AMI patients admitted to AMI-Kyoto Multi-Center Risk Study Group hospitals were retrospectively analyzed, and the clinical characteristics and in-hospital prognosis of these patients were reviewed. Patients with pre-hospital delay [elapsed time (ET)>12 h] had a lower frequency of Killip≥3 (9.3%) and less frequently received primary PCI (77.7%) compared with patients with ET≤12 h. In the ET>12 h group, older patients or patients with MI history tended to be complicated by heart failure. Primary PCI was performed for patients with ET>12 h, irrespective of the severity of heart failure [Killip 1 (78.7%) vs Killip≥2 (74.0%); p=0.3827]. On multivariate logistic regression analysis, age [odds ratio (OR) 1.053], MI history (OR 2.860), Killip≥2 (OR 10.235), and multi-vessels or left main coronary artery as culprit (OR 11.712) were significant independent positive predictors of in-hospital mortality for patients with ET>12 h. Practice of primary PCI was not a significant negative predictor for patients with ET>12 h (OR 0.812), but it was for patients with ET≤12 h (OR 0.425).

Conclusions: These findings indicate that patients with ET>12 h have a less severe condition and less frequently receive primary PCI compared with patients with ET≤12 h. Although primary PCI is often performed for these patients irrespective of the severity of heart failure, no preferable effect of primary PCI on the in-hospital mortality is demonstrated. In contrary, practice of primary PCI is a significant negative predictor of in-hospital mortality for patients with ET≤12 h.