Canada Acute Coronary Syndrome Risk Score: a new risk score for early prognostication in acute coronary syndromes.

Background: Despite the availability of several acute coronary syndrome (ACS) prognostic risk scores, there is no appropriate score for early-risk stratification at the time of the first medical contact with patients with ACS. The primary objective of this study is to develop a simple risk score that can be used for early-risk stratification of patients with ACS.
Methods: We derived the risk score from the Acute Myocardial Infarction in Quebec and Canada ACS-1 registries and validated the risk score in 4 other large data sets of patients with ACS (Canada ACS-2 registry, Canada-GRACE, EFFECT-1, and the FAST-MI registries). The final risk score is named the Canada Acute Coronary Syndrome Risk Score (C-ACS) and ranged from 0 to 4, with 1 point assigned for the presence of each of these variables: age ≥75 years, Killip >1, systolic blood pressure <100 mm Hg, and heart rate >100 beats/min. The primary end points were short-term (inhospital or 30-day) and long-term (1- or 5-year) all-cause mortality.
Results: The C-ACS has good predictive values for short- and long-term mortality of patients with ST-segment elevation myocardial infarction and non-ST-segment elevation ACS. The negative predictive value of a C-ACS score ≥1 is excellent at ≥98% (95% CI 0.97-0.99) for short-term mortality and ≥93% (95% CI 0.91-0.96) for long-term mortality. In other words, a C-ACS score of 0 can potentially identify correctly ≥97% short-term survivors and ≥91% long-term survivors.
Conclusion: The C-ACS risk score permits rapid stratification of patients with ACS. Because this risk score is simple and easy to memorize and calculate, it can be rapidly applied by health care professionals without advanced medical training.
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