Coronary artery calcification progression is associated with arterial stiffness and cardiac repolarization deterioration in hemodialysis patients.

BACKGROUND/AIMS: Evidence suggests that vascular calcification (VC) portends poor cardiovascular (CV) prognosis in patients undergoing maintenance dialysis (CKD-5). Nonetheless, how VC might predispose to CV mortality still remains to be clarified. Herein, we report on the association between coronary artery calcification (CAC) progression and changes in cardiac repolarization as well as arterial stiffness. METHODS: 132 patients new to dialysis were identified. Demographic and clinical characteristics were collected at study entry and during the 12-month follow-up. CAC, 12-lead ECG and pulse wave velocity (PWV) were assessed at baseline and study completion. Uni- and multivariable analyses were applied to detect factors associated with worsening of cardiac repolarization (QTd) and arterial stiffness (PWV). RESULTS: Uni- and multivariable analyses revealed that CAC progression was associated with a significant increase in both QTd and PWV. Every 20-unit increase in the CAC score corresponded to a significant 23% (95% CI 1.12-1.27; p < 0.001) and 32% (95% CI 1.09-1.37; p < 0.01) increase in the risk of experiencing a 1-m/s increase in PWV and 1 ms in QTd, respectively. CONCLUSION: VC is a marker of vasculopathy and appears to be associated with cardiac repolarization and arterial stiffness abnormalities in CKD-5 patients.

Vascular calcification and QT interval in incident hemodialysis patients.

This study proposes [corrected] to evaluate the impact of different phosphate binders on the slowing of [corrected]cardiovascular calcification [corrected] and QT dispersion in incident haemodialysis patients with a follow-up of [corrected] 36 months. This is to be a [corrected] randomized, multicenter, perspective, [corrected] interventional study. Inclusion criteria are age over 18 years and being an [corrected] incident patient [corrected] on hemodialysis. Exclusion criteria are congenital prolongation of QT segment syndrome, QT-c >440 ms, bradycardia <50 beats per minute, symptomatic [corrected] arrhythmia or any other significant heart problems; electrolyte imbalances [corrected] (especially hypokalemia, hypomagnesemia or [corrected] hypocalcemia); abnormal liver function tests and [corrected] hypothyroidism. An informed consent will be taken at study entry. The patients will be randomized to 2 cohorts: [corrected] 180 patients in the sevelamer [corrected] group and 180 patients in calcium-binder phosphate group. Related vascular calcification mortality is the principal end point [corrected] and will be evaluated at 36 months.

Cardiac vascular calcification and QT interval in ESRD patients: is there a link?

We will present our experience and our preliminary data about the correlation between cardiac calcification and QT interval (and QT dispersion) in uraemia. We studied 32 haemodialysis (HD) patients (age 69 +/- 16 years, time on dialysis 32 +/- 27 months) and 12 chronic kidney disease stage 4 (CKD-4) patients (age 66 +/- 17 years, uraemia duration 38 +/- 16 months). The patients were characterized by a good mineral control, as shown by serum phosphate levels (3.6 +/- 1.3 mg/dl in CKD-4 and 4.3 +/- 1.6 mg/dl in HD patients) and Ca x P product (46 +/- 17 and 49 +/- 16 mg(2)/dl(2), respectively). The parathyroid hormone levels were higher in HD than CKD-4 patients (p < 0.0001). A TC score >400 was found to be highly prevalent in both groups. Significantly more HD patients (62.5%) showed cardiac calcification than CKD-4 patients (33%; p = 0.01). The patients were matched for TC scores higher or lower than 400. The two groups differed by gender (p < 0.05), age (p = 0.026), frequency of diabetes mellitus (p < 0.01), uraemia follow-up period (p < 0.001), low-density lipoprotein cholesterol level (p = 0.009), Ca x P product (p = 0.002), parathyroid hormone level (p < 0.0001), and corrected QT dispersion (p < 0.0001). The QT interval was higher in HD and CKD-4 patients with higher TC scores (approximately 11%), but QT interval dispersion was significantly higher in patients with TC scores >400. QT dispersion showed a linear correlation with TC scores in both groups (r = 0.899 and p < 0.0001 and r = 0.901 and p < 0.0001). Male gender, age, time (months) of uraemia, low-density lipoprotein cholesterol, albumin, calcium x phosphorus product, parathyroid hormone, and TC score are important determinants of QT dispersion. Our data show that it is possible to link dysrhythmias and cardiac calcification in uraemic patients.