Abstract 1529: Predictive Values of a New Risk Score (C-AMI) in ST-Segment Elevation Myocardial Infarction.
Background: In the acute management of ST-segment elevation (STEMI), a simple and easy to use risk score would be helpful in the early detection of high-risk patients (pts). We hypothesize that a simple risk score, which incorporates age, Killip class, heart rate and blood pressure, would be predictive of mortality in STEMI.
Methods: The Canadian ACS-1 Registry was a prospective cohort study in 1999–2001 (51 hospitals); the AMI-QUEBEC study was a retrospective cohort study in 2003 (17 hospitals). The in-hospital mortality was reported in both datasets; 1-year mortality was available only in the Canadian ACS-1 Registry. The proposed risk score, the C-AMI (for CANADA-AMI) was a priori defined as the sum of 4 dichotomous variables: age ≥75 years, Killip ≥2, initial heart rate >100/min and systolic blood pressure <100 mmHg. Those variables were selected based on their independent association with mortality in our cohorts. Each attribute is worth one point, with the score ranging from 0 – 4. We calculated the c-statistics for the C-AMI score in each dataset independently.
Results There were 3,219 pts: 1,702 (ACS-1 Registry) and 1,517 pts (AMI-QUEBEC). The mean age and % of females were similar in the two cohorts (61.5±13.1 years and 27% females). The in-hospital mortality in the combined registries, for pts with C-AMI scores of 0,1,2 and ≥3 was 2%, 9%, 18% and 28%, respectively. The one-year mortality was 5%, 14%, 30% and 38%, respectively. The c-statistics ranged from 0.72– 0.78 for in-hospital mortality and was 0.72 for 1-year mortality (Table⇓)
Conclusion: The C-AMI risk score had good predictive values for in-hospital and 1-year mortality. A C-AMI score of 0 predicted very low mortality and conversely, C-AMI score ≥2 predicted markedly increased mortality. Since this score is straightforward and can be determined without the aid of a calculator, it may be helpful in the rapid stratification of pts with STEMI.