Background 

Congenital coronary artery anomalies (CCAAs) have the potential for life-threatening complications, including malignant ventricular arrhythmias and sudden cardiac death (SCD). In this study, we aimed to evaluate the relationship between impaired repolarization parameters and poor cardiovascular clinical outcomes in patients with potentially serious CCAAs.

Methods 

This retrospective study included 85 potentially serious CCAA patients (mean age: 54.7 ± 13.6 years; male:44) who were diagnosed with conventional and coronary computed tomography angiography (CCTA). All patients underwent transthoracic echocardiography and 12-lead surface electrocardiography. Cardiac events were defined as sustained ventricular tachycardia or fibrillation, syncope, cardiac arrest and SCD.

Results 

The presence of interarterial course (IAC) was confirmed by CCTA in 37 (43.5%) patients. During a median follow-up time of 24 (18–50) months, a total of 11 (12.9%) patients experienced cardiac events. The presence of IAC was significantly more frequent and Tp–e interval, Tp–e/QTc ratio and frontal QRS/T angle (fQRSTa) were significantly greater in patients with poor clinical outcomes. Moreover, the presence of IAC, high Tp-e/QTc ratio and high fQRSTa were found to be independent predictors of poor clinical outcomes and decreased long-term cardiac event-free survival in these patients. A net reclassification index was +1.0 for the Tp-e/QTc ratio and +1.3 for fQRSTa which were confirmable for additional predictability of these repolarization abnormalities

Conclusion 

Impaired repolarization parameters, including wider fQRSTa, prolonged Tp–e interval, and increased Tp–e/QTc ratio, and IAC may be associated with poor cardiovascular clinical outcomes in potentially serious CCAA patients.