Abnormal spatial QRS-T angle predicts mortality in patients undergoing dobutamine stress echocardiography for suspected coronary artery disease.

Objective: To investigate the association between (cardiac) mortality and spatial QRS-T angle in patients undergoing dobutamine - atropine stress echocardiography (DSE) for evaluation of known or suspected coronary disease.

Methods: Between 1990 and 2003, 2347 patients underwent DSE for evaluation of coronary disease at the Erasmus Medical Center. Echocardiographic images were analyzed offline using a 16-segment, 5-point scoring model for regional function. Twelve-lead resting ECGs were analyzed and patients were grouped in three categories according to their spatial QRS-T angle: normal (0-105 degrees), borderline (105-135 degrees), and abnormal (135-180 degrees).

Results: Mean age was 61+/-13 years, 66% were male, 32% had hypertension, 26% had hypercholesterolemia, 28% were smokers, and 12% were diabetic. During a mean follow-up of 7+/-3.4 years, 26.5% (623) of the patients died; 15.3% (359) died due to a cardiac cause. Abnormal QRS-T angle (135-180 degrees ) was present in 21% of the patients. Abnormal QRS-T angle was a predictor of cardiac death [hazard ratio: 3.2 (2.6-4.1)] and all-cause mortality [hazard ratio: 2.2 (1.8-2.6)]. After multivariate analysis abnormal and borderline QRS-T angle, peak wall motion score, age, male sex, history of diabetes, history of heart failure, smoking, and hypertension were independent predictors of (cardiac) death.

Conclusion: Abnormal QRS-T angle is an independent predictor of (cardiac) death in patients undergoing DSE. Abnormal QRS-T angle should be considered as a risk factor in stable patients evaluated for coronary disease.