Parathyroidectomy is associated with slow progression of vascular calcification in maintenance haemodialysis patients: A propensity score-matched case–control study

Abstract

Parathyroidectomy has been the mainstay of treatment of severe hyperparathyroidism in patients with kidney failure until the introduction of calcimimetic. Several large observational studies demonstrated the improvement in patient outcomes after parathyroidectomy. The benefit of parathyroidectomy on vascular calcification remains largely unexplored. Aim: To examine the association between parathyroidectomy and the progression of vascular calcification as well as overall survival in maintenance haemodialysis patients. Method: This is a matched case–control study undertaken between 2012 and 2020. Patients who underwent parathyroidectomy were identified and matched 1:1 to non-parathyroidectomized (non-PTX) haemodialysis patients using propensity score matching method resulting in 120 patients in each arm. Aortic arch calcification (AoAC) score was determined annually in the posteroanterior chest x-ray. The average follow-up period was 38 months. Results: Baseline demographic, laboratory data and AoAC score were comparable among the two groups of patients. The prevalence of AoAC was 59% in the PTX group and 54% in the non-PTX group (p =.43). Progression of AoAC occurred in 33% in the PTX group and 47% in the non-PTX group (p =.04). Multivariate generalized linear model revealed parathyroidectomy as an independent protective factor [β (95% CI) −1.04 (−1.68, −0.41)] and increased serum calcium as a potentiating factor [β (95% CI) 0.62 (0.25, 0.1)] for progression of AoAC. Linear mixed models revealed an increase in AoAC score in both groups but between group comparisons indicated substantially slower progression in the PTX group. Rapid progression of AoAC was also observed more frequently among non-PTX patients. Death occurred in 7 and 16% in the PTX and non-PTX groups, respectively. Kaplan–Meier survival curve revealed better survival associated with parathyroidectomy (p =.01). More rapid progression of AoAC also correlated with worse survival. Conclusion: Parathyroidectomy was associated with slow progression of vascular calcification in maintenance haemodialysis patients.