The Cardiac Infarction Injury Score as a predictor for long-term mortality in survivors of a myocardial infarction

Abstract

Aims: The Cardiac Infarction Injury Score (CIIS) is an electrocardiographic classification system that was developed as a diagnostic tool to assess the extent of cardiac injury in acute myocardial infarction. We investigated the prognostic value of the CIIS in post-myocardial infarction patients. Methods and Results: The prognostic values of the CIIS for total and cardiac mortality was assessed in a large series (n = 3395) of patients who were enrolled in the ASPECT trial. Standard 12-lead electrocardiograms, recorded prior to hospital discharge were coded according to the CIIS and the Minnesota Code. Mean CIIS was 26 (range -8 to 59). After adjustment for other baseline characteristics, the CIIS was directly related to the risk of total mortality and cardiac mortality. At one-year follow-up the relative risks of CIIS ≤ 40, CIIS 30-40 and CIIS 20-30 were significantly higher than in those with a CIIS < 20. The relative risks were, respectively, 2.3 (1.2-4.4), 2.2 (1.3-3.9) and 1.6 (0.9-2.9). At 3 year follow-up, the relative risks were, respectively, 2.1 (1.4-3.2), 1.7 (1.2-2.4) and 1.5 (1.0-2.1). The relative risks for total mortality were similar. When patients with major ECG abnormalities, as defined by the Minnesota code, were excluded, the associations were still significant in the CIIS classes 30-40 and > 40. Conclusion: The CIIS ECG scoring system is an important predictor for long-term cardiac mortality in post myocardial infarction patients. It can easily be automated and is efficient for classifying cardiac injury in epidemiological studies.