Association between preinfarction angina and angiographic findings in non-ST-segment elevation myocardial infarction

Background The association between preinfarction angina and angiographic findings has not been elucidated in patients with non-ST-segment elevation myocardial infarction (NSTEMI). Hypothesis Patients with preinfarction angina have favorable angiographic findings. Methods This retrospective study analyzed 481 patients who underwent coronary angiography within 5 days of presenting NSTEMI. Preinfarction angina was defined as experiencing ≥1 chest-pain episode within 7 days prior to admission. Infarct size was measured as the peak cardiac troponin I (cTnI) level, and large myocardial infarction (MI) was defined as a peak cTnI level >85th percentile value in the study population. Infarct-related artery (IRA) patency was defined as Thrombolysis In Myocardial Infarction grade 2 or 3 flow. Clinical and angiographic characteristics and in-hospital mortality were compared between patients with and without preinfarction angina. Results Among 481 patients, 200 (42%) had preinfarction angina. Preinfarction angina was associated with smaller infarct size, indicated by lower peak cTnI levels (P = 0.006) and lower incidence of large MI (P = 0.02), and IRA patency (P = 0.03). There was no significant difference in in-hospital mortality. On multivariate analysis, both preinfarction angina (odds ratio: 0.53, 95% confidence interval: 0.29-0.94, P = 0.03) and IRA patency (odds ratio: 0.30, 95% confidence interval: 0.17-0.52, P < 0.001) were independent negative predictors of large MI. Conclusion Our study demonstrates that preinfarction angina is a predictor of smaller infarct size and infarct-related artery patency in NSTEMI patients, suggesting that NSTEMI patients presenting without preinfarction angina are at increased risk of developing a large MI.