Clinical characteristics of patients with acute myocardial infarction who did not undergo primary percutaneous coronary intervention - Report from the MIYAGI-AMI registry study

Background: In the current era of primary percutaneous coronary intervention (PCI), some patients with acute myocardial infarction (AMI) still do not undergo primary PCI. Methods and Results: To examine the clinical characteristics of AMI patients who did not undergo primary PCI, we analyzed patients enrolled between 2002 and 2010 in the MIYAGI-AMI Registry Study, in which all AMI patients in the Miyagi prefecture have been prospectively registered. Among a total of 8,640 patients, 1,879 (21.7%) did not undergo primary PCI and their in-hospital mortality was significantly worse compared with those who did (21.4% vs. 6.4%, P<0.01). Multivariate analysis demonstrated that female sex was significantly associated with non-performance of primary PCI [odds ratio (95% confidence interval): 1.40 (1.22-1.61), P<0.001], along with age [1.01 (1.01-1.02), P<0.001] and heart failure on admission [2.69 (2.29-3.16), P<0.001]. When dividing by age, the nonperformance rate of primary PCI in females showed a U-shaped prevalence, whereas it simply increased with aging in males. Importantly, female patients aged <80 years had a significantly higher non-performance rate of primary PCI compared with male patients, regardless of the severity of AMI. Conclusions: These results indicate that in the current PCI era, various factors, including aging, heart failure on admission and sex differences, are associated with non-performance of primary PCI, which remain to be resolved in order to further improve critical care of AMI.