Predictors and Impact of In-Hospital Recurrent Myocardial Infarction in Patients With Acute Coronary Syndrome: Findings From Gulf RACE-2

Background: Little is known about the predictors and prognostic impact of recurrent in-hospital ischemia and infarction in patients with acute coronary syndrome (ACS). Our objectives were to determine the baseline characteristics, risk factors, and long-term outcomes of patients with recurrent myocardial infarction (Re-MI).

Methods: We evaluated patients with ACS who were enrolled in the second Gulf Registry of Acute Coronary Events from October 2008 to June 2009.

Results: Of 7925 patients with ACS, 167 (2.1%) developed in-hospital Re-MI. Patients with Re-MI were older (mean age: 58.7 ± 13.4 vs 56.8 ± 12.6; P = .045), had higher rates of hyperlipidemia (42.5% vs 32.6%; P = .019), and were more likely to present with ST-segment elevation myocardial infarction (STEMI; 74.25% vs 43.9%; P < .001) and Killip class 4 (8.4% vs 3.2%; P < .001) than patients without Re-MI. Patients with Re-MI were less likely to receive evidence-based therapies upon admission, including aspirin (94.6% vs 98.5%; P < .001), β-blockers (59.3% vs 74.7%; P < .001), and statins (86.8% vs 94.9%; P < .001), and were less frequently assessed with coronary angiography (29.3% vs 32.5%; P = .029). Predictors of recurrent events included history of angina, hypotension on presentation, admission diagnosis of STEMI, and decreased use of evidence-based therapies including aspirin, statins, and β-blockers upon admission. Patients with Re-MI had more in-hospital complications, including congestive heart failure (44.3% vs 12.4%) and cardiogenic shock (26.4% vs 5.3%), as well as higher mortality rates during hospitalization (23.4% vs 4.1%) and after a discharge period of 30 days (27% vs 7.8%) and 1 year (30.5% vs 11.7%; P < .001 for all comparisons).

Conclusion: In our study, patients with Re-MI were less likely to receive evidence-based therapies and had a worse prognosis in terms of in-hospital complications and higher mortality rates. High-risk patients should be monitored and managed differently to prevent secondary attacks.