A Combination of Heart Rate-Corrected QT Interval and GRACE Risk Score Better Predict Early Mortality in Patients with Non-ST Segment Elevation Acute Coronary Syndrome

Abstract

Objective: This study aimed to evaluate whether the addition of heart rate-corrected QT interval prolongation to the Global Registry of Acute Coronary Events risk score improves the predictive value for early mortality in patients with non-ST segment elevation acute coronary syndrome. Methods: We retrospectively screened our database for consecutive non-ST-segment elevation acute coronary syndrome patients between January 2017 and July 2019. The demographic and clinical parameters were acquired via chart review. All electrocardiograms were reviewed by 2 physicians. QT interval was measured using the tangent method. Early mortality was defined as all-cause death observed during the hospital stay or within 30 days after discharge. Results: The final study population consisted of 283 patients, there were 17 early deaths. Ten of 59 patients with prolonged corrected QT intervals died (16.9%, P < .001). Both the Global Registry of Acute Coronary Events risk score (odds ratio: 1.032; 95% CI: 1.012-1.053; P = .002) and corrected QT interval (odds ratio: 1.026; 95% CI: 1.007-1.045; P = 0.007) independently predicted early mortality. The area under value was 0.769 (95% CI: 0.674-0.863, P < .001) for the corrected QT interval and 0.780 (95% CI:0.681-0.878; P < .001) for the Global Registry of Acute Coronary Events risk score alone. However, when the corrected QT interval and the Global Registry of Acute Coronary Events risk score were combined, it was found to be 0.808 (95% CI: 0.713-0.904, P < .001). Conclusion: This study is the first to report that prolonged corrected QT and the Global Registry of Acute Coronary Events risk score independently predict early mortality and a combination of these 2 factors may improve the predictive value for early mortality in patients with ST-segment elevation acute coronary syndrome.