Serial Changes of QT Dispersion in Continuous Ambulatory Peritoneal Dialysis Patients

Lee, Sang Choel; Han, Seung Hyeok; Lee, Jeung Eun; Yoon, Soo Young; Kim, Beom Seok; Kang, Shin Wook; Lee, Ho Yung; Han, Dae Suk; Choi, Kyu Hun

Abstract

PURPOSE
To evaluate the changes of QT dispersion (QTd) in CAPD patients serially from the period before the initiation of CAPD until several years after CAPD, and to find any associated factors.
METHODS
We performed a retrospective cohort study with a total of 101 patients who initiated CAPD between 1990 and 1996. All data were recruited from the patients' medical records before CAPD initiation, within one year after CAPD, and between one and three years after CAPD.
RESULTS
QTd and Corrected QTd (QTdc) values after CAPD did not show differences in the paired t-test of those before CAPD and within one year after CAPD. There was a definite correlation between the QTds before CAPD and that within one year after CAPD (r=0.530, p<0.001). In addition, the QTds from within one year after CAPD showed a correlation with those taken from one to three years after CAPD (r=0.487, p=0.019). Upon analysis of all-cause mortality, the change rate of QTd after CAPD initiation was revealed as a predicting factor along with the QTd, QTc max, and QTdc within one year after CAPD (RR=1.055, p=0.005). The change rate also remained a predictor of cardiovascular mortality (RR= 1.088, p=0.007). In a multivariate Cox regression, cardiomegaly and previous cardiovascular disease were revealed to be independent factors for the change rate of QTd.
CONCLUSION
QTd in CAPD patients did not change after initiation of CAPD, and the change rate of QTd after CAPD initiation was revealed as a risk factor for both all-cause mortality and cardiovascular mortality.