Atrial Fibrillation on Admission Is Related With Higher Mortality in ST-Segment Elevation Myocardial Infarction Patients Lessons From the Korea Acute Myocardial Infarction Registry (KAMIR)

The prognostic significance of atrial fibrillation (AF) on mortality in ST-segment elevation myocardial infarction (STEMI) patients is not clearly understood. To elucidate the clinical significance of AF on mortality for 1 year in STEMI patients, we retrospectively analyzed the Korea Acute Myocardial Infarction Registry (KAMIR) database, which spans January 2008 to September 2010 and includes 14,329 patients with acute myocardial infarction. We selected 5,556 patients with marked ECG rhythm (NSR, normal sinus rhythm or AF) on emergency room arrival, < 12 hours of symptom onset, and who underwent primary percutaneous coronary intervention (PCI) within 90 minutes of arriving at the hospital. Patients who had been followed-up for at least for 1 year were analyzed (2,636 of NSR, 119 of AF). At enrollment, AF patients were older (70.7 versus 65.5 years, P < 0.001) and had lower systolic blood pressure (120.6 versus 125.9 mmHg, P = 0.050), a higher heart rate (80.4 versus 75.6/minute, P = 0.009), and a higher rate of Killip III, IV (25.0 versus 14.2%, P = 0.002). Patients with AF showed clearly higher all-cause mortality (22.7 versus 9.5%, HR 2.51, 95%CI 1.68 similar to 3.76, P < 0.001) and cardiac death rate (17.7 versus 7.5%, HR 2.49, 95%CI 1.59 similar to 3.90, P < 0.001) at 1 year after admission compared patients with NSR. AF induced significantly higher all-cause mortality and cardiac mortality rate in STEMI patients who were appropriately revascularized with primary PCI compared to NSR at 1 year.