Factors associated with prolonged QTc interval in Iranian population: MASHAD cohort study

QTc interval prolongation is a growing global issue which can cause torsades de pointes, a potentially fatal arrhythmia. We aimed to identify risk factors for prolonged QT interval in men and women.

The Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study collected electrocardiogram interval data. QT was corrected for heart rate using the Bazett's formula. Ordinal logistic regression with crude (univariable) and adjusted (multivariate) association analyses in the form of odds ratio and corresponding 95% confidence interval (CI) were used to identify the factors associated with QTc prolongation.

A total of 8878 individuals including 5318 females and 3560 males, aged 35 to 65 years, were included in this cross-sectional study. Participants with QTc prolongation were more likely to be older and have hypercholesterolemia, hypertension (HTN), and Type 2 diabetes mellitus (T2DM), but to have lower levels of physical activity (P < 0.05). Age (OR = 1.68, 95%CI = 1.18-2.39), hypercholesterolemia (OR = 1.77, 95%CI = 1.24-2.51), HTN (OR = 1.36, 95%CI = 1.06-1.73), T2DM (OR = 1.59, 95%CI = 1.19-2.13), severe anxiety (OR = 1.80, 95%CI = 1.05-3.11) and mild depression (OR = 1.38, 95%CI = 1.01-1.88) were independent risk factors for prolonged QTc interval in men. For women, only HTN (OR = 1.29, 95%CI = 1.02-1.63) and T2DM (OR = 1.50, 95%CI = 1.14-1.97) were independent risk factors.

Older age, Hypercholesterolemia, HTN, T2DM, severe anxiety and mild depression in men, and HTN and T2DM in women were associated with high risk of prolonged QTc interval. Healthcare practitioners should be aware of the risk factors of QTc interval prolongation and should exercise caution in the management of certain patients.