Association of frontal QRS-T angle--age risk score on admission electrocardiogram with mortality in patients admitted with an acute coronary syndrome

Abstract

Risk assessment is central to the management of acute coronary syndromes. Often, however, assessment is not complete until the troponin concentration is available. Using 2 multicenter prospective observational studies (Evaluation of Methods and Management of Acute Coronary Events [EMMACE] 2, test cohort, 1,843 patients; and EMMACE-1, validation cohort, 550 patients) of unselected patients with acute coronary syndromes, a point-of-admission risk stratification tool using frontal QRS-T angle derived from automated measurements and age for the prediction of 30-day and 2-year mortality was evaluated. Two-year mortality was lowest in patients with frontal QRS-T angles <38° and highest in patients with frontal QRS-T angles >104° (44.7% vs 14.8%, p <0.001). Increasing frontal QRS-T angle-age risk (FAAR) scores were associated with increasing 30-day and 2-year mortality (for 2-year mortality, score 0 = 3.7%, score 4 = 57%; p <0.001). The FAAR score was a good discriminator of mortality (C statistics 0.74 [95% confidence interval 0.71 to 0.78] at 30 days and 0.77 [95% confidence interval 0.75 to 0.79] at 2 years), maintained its performance in the EMMACE-1 cohort at 30 days (C statistics 0.76 (95% confidence interval 0.71 to 0.8] at 30 days and 0.79 (95% confidence interval 0.75 to 0.83] at 2 years), in men and women, in ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction, and compared favorably with the Global Registry of Acute Coronary Events (GRACE) score. The integrated discrimination improvement (age to FAAR score at 30 days and at 2 years in EMMACE-1 and EMMACE-2) was p <0.001. In conclusion, the FAAR score is a point-of-admission risk tool that predicts 30-day and 2-year mortality from 2 variables across a spectrum of patients with acute coronary syndromes. It does not require the results of biomarker assays or rely on the subjective interpretation of electrocardiograms.