Prognostic importance of the QT interval in patients with chronic kidney disease 5d stage

Abstract

The aim : to clarify the safe range of the values of the corrected QT interval and to identify risk factors that contribute to its increase in patients with end-stage renal disease who receive treatment with programmed hemodialysis (HD). Patients and methods . 70 patients (26 men and 44 women) with end-stage renal disease receiving HD were observed for 5 years. The average age was 58.5 ± 14.7 years. A traditional clinical and laboratory examination, echocardiography was performed in all patients. The value of the QT interval corrected for the frequency of ventricular contractions was calculated using the Framingham formula. The patients were clinically stable, there were no violations of heart rhythm and conduction requiring medical correction. Results. During 5 years of observation, 23 patients died. Given the different number of men and women among the surveyed, mortality rates were calculated separately for each of the gender groups. For men, mortality was 27% or 6.7 per 100 patient-years (6.7 per 100 people per year). For women, respectively, 36.4% or 8.5 per 100 patient-years (8.5 per 100 people per year). The chance of sudden cardiac death for men was 0.37, for women - 0.57. Thus, the risk of sudden cardiac death in women was 1.5 times higher than in men. The guidelines for the QT interval are proposed for the general population. We calculated the prognostic value of the QT interval in relation to sudden cardiac death in our patients was 440 msec or more; the area under the ROC curve is 0.978 (95% CI 0.911-0.998), p = 0.0001. Sensitivity 95.6%, specificity 100%. A number of identifiable indicators during the five-year observation period has changed (delta). There were identified correlations between the value of QT and the delta of body mass index Rs = -0.458 p = 0.002; delta of hemoglobin Rs = -0,338 p = 0.025; delta width of the distribution of platelets by volume Rs = 0.377 p = 0.011. Conclusion. The data of our study allow us to offer for practical application a dynamics study of the PQ interval in comparison with the dynamics of body mass index, hemoglobin level and the width of the distribution of platelets by volume. This approach seems to us very important primarily in clinically stable patients with the PQ ≥ 440 msec interval corrected for the frequency of ventricular contractions.