Vascular calcification: “The silent killer” in the hemodialysis population in Qatar

Abstract

Background: Calcification is an abnormal deposition of calcium salts in vascular tissue, including valves, blood vessels, and the heart, which is highly prevalent in End Stage Renal Disease (ESRD) patients. Vascular calcification is an independent and important risk factor for cardiovascular events in hemodialysis patients and investigators have demonstrated that the extent and histo-anatomic type of vascular calcification are predictors of subsequent vascular mortality. Cardiovascular mortality risk is elevated 5-10-fold in ESRD patients compared to the general population. As we recognized the importance of early detection and delaying the complication of calcification, this study was initiated in March 2020 among 650 haemodialysis patients in Hamad General Hospital in Qatar. Methods: The haemodialysis multidisciplinary team identified patients with vascular calcification. Data was collected on available imaging study which included echocardiography, X-rays, and computed tomography (CT) to detect any kind of vascular calcification (e.g. valvular, calcified vessels). Our management protocol was updated to decrease the calcium load and active vitamin D. Abnormal serum calcium management was initiated to monitor and delay the progression of vascular calcification through interventions which included dietary control, medication, and dialysate bath. Results: We were able to screen 86% of dialysis patients (n = 559). Following the interventions, the percentage of patients with a calcium level of 2.1-2.55 mmol/l increased by 5 percentage points from 83% in March 2020 to 88% in September 2020 (p value = 0.004). Phosphorus level was maintained in the range of 0.81-1.8 mmol/l for 82% of patients and parathyroid hormone (PTH) level in the range 150-400 pg/ml for 72% of patients. Conclusion: We implemented a successful screening program for vascular calcification in dialysis patients combined with specific interventions. Reduced hypercalcemia episodes can delay vascular calcification. Serum calcium level was improved and maintained within the target range (2.1 - 2.55 mmol/l) for a larger number of patients.