Cardiovascular calcification in hemodialysis patients: A Qatar-based prevalence and risk factors study

Patients with end-stage kidney disease on hemodialysis (HD) have an increased risk of death due to the high prevalence of cardiovascular disease. Vascular calcification (VC) is predictive of cardiovascular disease and mortality. We conducted a study to evaluate the prevalence and risk factors for VC in dialysis patients in Qatar.

This is a retrospective nationwide study including all chronic ambulatory dialysis patients in Qatar from 2020 to 2022. We used our national electronic medical record to track demographics, clinical characteristics, comorbidities, laboratory values, and diagnostic data for each patient. Calcifications were assessed by echocardiography (routinely done for all our dialysis population per national protocol), computed tomography, X-ray, and ultrasound. The study protocol was approved by the local medical research ethics committee (MRC-01-20-377).

842 HD patients were included in this study. Vascular calcifications (VC) were prevalent in 52.6% of patients. The main site of VC was Mitral valve calcifications in 55.5% of patients. Patients with VC were significantly older and had more prevalence of diabetes mellitus (p = 0.001 and p = 0.006, respectively). There was no statistically significant difference between patients with calcifications and patients without calcifications regarding serum calcium, phosphorus, and PTH level. In multivariate analysis, age and diabetes significantly increased the risk factor for calcification (95% CI 1.033-1.065, p < 0.0001, and 95% CI 1.128-2.272, p < 0001, respectively). Moreover, higher vitamin D levels and higher doses of IV Alfacalcidol were significant risk factors for calcifications (95% CI 1.005-1.030, p < 0.007, and 95% CI 1.092-1.270, p < 0.0001, respectively).

Our study found that vascular calcification was widespread among our dialysis population in Qatar. Implementing the practice of echocardiography in dialysis patients was extremely helpful and the most productive in detecting vascular calcification. Diabetes mellitus almost doubles the risk for vascular calcifications in dialysis patients. These results are beneficial in identifying risk factors for vascular calcification, which can help stratify dialysis patients' risk of cardiovascular disease and optimize prevention efforts.