A large frontal QRS-T angle is a strong predictor of the long-term risk of myocardial infarction and all-cause mortality in the diabetic population

BACKGROUND: A large angle between the QRS vector and the T-wave vector (QRS-T angle) in electrocardiograms (ECGs) has recently been introduced as a marker of poor prognosis. The prognostic value in diabetes is unknown. We assessed the long-term predictive power of the frontal plane QRS-T angle in the diabetic population.

METHODS: In 1992-93, the diabetic population of the municipality of Horsens, Denmark, was delineated by the prescription method, and an age- and gender-stratified sample of 240 diabetic persons was randomly selected. In 2015, 12-lead ECGs taken in 1993-94 were analyzed. Vital statistics were obtained from the Danish Civil Registration System and data regarding hospitalizations taken from The National Patient Registry in July 2015.

RESULTS: In total, 178 people agreed to participate (74%) in the study, with the mean (sd) age being 58.9 (10.2) years and 56% being male. The total observation time was 21.5 (0.18) years, during which time 122 (69%) persons died, 32 (18%) suffered a myocardial infarction (MI) and 126 (71%) reached the composite endpoint of non-fatal MI or all-cause death. In Cox regression multivariate analysis a QRS-T angle above 90° was found to be an independent predictor of all-cause death (HR=2.2 (95% CI: 1.3-3.8)), MI (HR=2.95 (95% CI: 1.1-7.7)) and MI or all-cause death (HR=2.0 (95% CI: 1.2-3.5)) (all p<0.05), when adjusting for the effects of co-variates (gender, age, length of diabetes, BMI, total cholesterol, diabetes type, hemoglobin A1c, smoking, hypertension and previous MI).

CONCLUSION: A large QRS-T angle is a strong, independent long-term predictor of all-cause mortality, MI and MI or all-cause death in the diabetic population.