Risk identification at the time of admission to coronary care unit in patients with suspected myocardial infarction.

The in-hospital clinical course was evaluated in 2,162 consecutive patients admitted with a diagnosis of suspected myocardial infarction. Of these, 1609 patients were considered to be in the high-risk group, based on the presence of 16 clinical criteria present at the time of admission. The remaining 553 patients were classified as low risk. The overall rate of complications in the coronary care unit was greater in the high-risk group, 64%, compared to 26% in the low-risk group (p less than 0.001). Similarly life-threatening events (occurrence or recurrence of ventricular fibrillation, sustained ventricular tachycardia, complete heart block, asystole, or cardiogenic shock) were more common in the high risk-group compared to the low-risk group, 11% and 0.9%, respectively (p less than 0.001). The high-risk group required significantly more interventions, such as electrical cardioversion, temporary pacing, pulmonary artery catheterization, and intraaortic balloon counterpulsation, compared to the low-risk group (20% vs 2%, respectively; p less than 0.001). Myocardial infarction was confirmed in 892 patients in the high-risk group (55%) compared to 90 (16%) in the low-risk group (p less than 0.001). The coronary care unit mortality rate was greater in the high-risk group compared to the low-risk group (8.2% vs 0.4%, respectively; p less than 0.0002). It is concluded that based on readily available clinical criteria at the time of admission, a subgroup of patients at low risk for developing life-threatening complications requiring coronary care unit interventions can be identified and admitted directly to an intermediate-care unit.