Impact of Parathyroid Hormone Level on Intracoronary Calcification and Short- and Long-Term Outcomes in Dialysis Patients Undergoing Percutaneous Coronary Intervention

Background: Dialysis patients have strong intracoronary calcification, accelerated by secondary hyperparathyroidism as well as atherosclerosis. We evaluated the association of intact parathyroid hormone (iPTH) level with intracoronary calcification evaluated by intravascular ultrasound (IVUS), and its impact on both stent expansion after percutaneous coronary intervention (PCI) and long-term clinical outcomes, in dialysis patients with coronary artery disease (CAD).Methods and Results: A total of 116 patients on dialysis, who underwent PCI with IVUS guidance between March 2012 and December 2020, were enrolled. Patients were divided into 2 groups based on their median iPTH level. The degree of intracoronary calcification was evaluated by calcification score using grayscale IVUS in the target lesions. Preprocedural calcification scores were significantly higher in the high iPTH group compared with the low iPTH group (2.9 +/- 1.1 vs. 2.1 +/- 0.7, P<0.001). After PCI, the high iPTH group had a significantly lower stent expansion index (0.6 +/- 0.2 vs. 0.7 +/- 0.1, P<0.001) and stent symmetry index (0.5 +/- 0.1 vs. 0.7 +/- 0.1, P<0.001) compared with the low iPTH group. The incidence of major adverse cardiac or cerebrovascular events within 3 years was significantly higher in the high iPTH group (log-rank P<0.05).Conclusions: High iPTH level is likely to increase intracoronary calcification, and cause inadequate stent expansion, which may be associated with increased risk of future adverse events in dialysis patients with CAD requiring PCI.