In this community-wide study, only one-third of the evaluated SCD cases had severe LV dysfunction meeting current criteria for prophylactic cardioverter-defibrillator implantation. The SCD cases with normal LV function had several distinguishing clinical characteristics. These findings support the aggressive development of alternative screening methods to enhance identification of patients at risk.

Background-In a recent cohort study, prolongation of the corrected QT interval (QTc) was associated with an independent increased risk of sudden cardiac death (SCD). We evaluated determinants of prolonged QTc and the relationship of prolonged QTc to SCD risk among patients with coronary artery disease in the general population. Methods and Results-A case-control design was used. Cases were SCD patients with coronary artery disease among a metropolitan area of 1 000 000 residents (2002 to 2006); controls were area residents with coronary artery disease but no history of SCD. All cases were required to have an ECG suitable for QTc analysis before and unrelated to the occurrence of SCD. A total of 373 cases and 309 controls met criteria for analysis. Mean QTc was significantly longer in cases than in controls (450Ϯ45 versus 433Ϯ37 ms; PϽ0.0001). In a multivariate model, gender, diabetes mellitus, and QTc-prolonging drugs were significant determinants of QTc prolongation in controls. In a logistic regression model predicting SCD, diabetes mellitus (odds ratio, 1.97; 95% confidence interval, 1.32 to 2.96) and use of QTc-prolonging drugs (odds ratio, 2.90; 95% confidence interval, 1.92 to 4.37) were significant predictors of SCD among subjects with normal or borderline QTc. However, abnormally prolonged QTc in the absence of diabetes and QT-prolonging medications was the strongest predictor of SCD (odds ratio, 5.53; 95% confidence interval, 3.20 to 9.57). Conclusions-Diabetes mellitus and QTc-affecting drugs determined QTc prolongation and were predictors of SCD in coronary artery disease. However, idiopathic abnormal QTc prolongation was associated with 5-fold increased odds of SCD. A continued search for novel determinants of QTc prolongation such as genomic factors is likely to enhance risk stratification for SCD in coronary artery disease. (Circulation. 2009;119:663-670.)

BACKGROUND-Published case reports have associated the therapeutic use of methadone with the occasional occurrence of sudden cardiac death. Because of the established utility of this drug and with the eventual goal of enhancing safety of use, we performed a community-based study to evaluate this association.

No abstract