Predicting the risk of prolongation of the mean daily QTc interval in patients with arterial hypertension

Arterial Hypertension (AH) is one of the leading causes of morbidity and mortality and is an urgent problem for more than 1.4 billion people worldwide. High mortality risks due to hypertension are associated with the risk of developing dangerous arrhythmias. These conditions can be diagnosed by changes in the QTc interval, which indicates an abnormal repolarization. The aim of the study was to determine the predictors of prolongation of the mean daily QTc interval in hypertension. We examined 195 patients (166 patients with hypertension and 29 patients without hypertension) who were treated at the (Kharkiv) City Polyclinic No.24. All patients were divided into 2 subgroups depending on the duration of the average daily QTc interval: 146 patients with normal QTc and 20 patients with prolonged QTc interval. Associations were determined using logistic regression with Wald's simultaneous inclusion and backward exclusion methods. The results showed that male gender was significantly associated with QTc prolongation (Odds Ratio (OR)=4.292 [95.0% confidence intervals (CI) 1.337–13.779], p=0.014), as did body mass index (BMI) (OR=1.107 [95.0% CI 0.987–1.243], p=0.083) and mean daily Diastolic and Pulse Blood Pressure (DBP and PBP), respectively, OR=1.076 [95.0% CI 1.017–1.139], p=0.011 and OR=1.075 [95.0% CI 1.012–1.141], p=0.018. The time since the diagnosis of hypertension (OR=1.093 [95.0% CI 0.997–1.197], p=0.057) and the office DBP (OR=0.948 [95.0% CI 0.900–0.999], p=0.046) were significantly associated with QTc prolongation. Ta­king into account the significant associations of male gender, BMI, mean daily DBP and SBP, time from diagnosis of hypertension, and office DBP with the risk of QTc prolongation, a prognostic model for determining the risk of QTc prolongation was developed, which has good qualification characteristics (sensitivity was 88.9% and specificity – 70.6%).