Cardiac Vascular Calcification and QT Interval in ESRD Patients: Is There a Link?

Abstract

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 × P product (46 ± 17 and 49 ± 16 mg²/dl², 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 × 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 × 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.

Coronary Artery Calcification Progression Is Associated with Arterial Stiffness and Cardiac Repolarization Deterioration in Hemodialysis Patients

“…Previous cross-sectional studies have already documented that VCs are closely associated with arterial stiffness [10,19] and in a previous paper we found an association between CAC and QTd [14] . However, these analyses add to the existing body of evidence by confirming these associations in a longitudinal study.…”

“…It has been suggested that QTd reflects heterogeneity of myocardial repolarization and predicts poor all-cause and CV survival independently on traditional CV risk factors in CKD-5 [27][28][29][30][31][32][33] . In a previous paper we showed an independent association between CAC and QTd, suggesting that subclinical vasculopathy might also be related to cardiac electrical impairments [14] . In this perspective, a couple of studies from the general population deserve mention.…”

“…QT dispersion (QTd)), suggesting that VC may affect cardiac repolarization and may predispose to cardiac arrhythmia [14][15][16] . However, to the best of our knowledge, no study has ever looked into these associations prospectively.…”

Impact of Vascular Calcification on Corrected QT Interval at the Time of Renal Transplantation

“…Di Iorio et al [14] found an association between QT dispersion, but not QTc interval duration and arterial calcifications. However, the study included patients at different stages of CKD and was hampered by the small sample size.…”

Impact of Vascular Calcification on QT Interval and QT Dispersion in CKD and Dialysis Patients

“…Claes et al [1] affirm that 'to the best of our knowledge, only one study so far has reported on the association between QT duration and arterial calcification in renal patients'. Di Iorio et al [2] found an association between QT dispersion (QT-d), but not QT-c interval duration and arterial calcifications. However, the study included patients at different stages of CKD and was hampered by the small sample size.…”