Risk Factors for Thromboembolic Events in Patients With Dialysis-Dependent CKD: Pooled Analysis of Four Global Roxadustat Phase 3 Trials

Introduction: Risk factors for thromboembolic events in patients with dialysis-dependent chronic kidney disease (CKD) receiving roxadustat are unknown. Iron deficiency has been reported as a risk factor for thrombosis in the general population. Methods: Thromboembolic events with onset before and after week 12 in patients receiving roxadustat were evaluated in this pooled analysis of four global phase 3 trials, PYRENEES, SIERRAS, HIMALAYAS, and ROCKIES. Baseline risk factors for thromboembolic events were investigated by Cox regression analyses. Nested case-control analyses with matched pairs of case-control data explored the relationship between thromboembolic events and last known laboratory parameters before event onset. Results: Of 2354 patients, 1026 thromboembolic events were observed in 568 patients. Baseline risk factors found included hemodialysis (vs peritoneal dialysis), advanced age (>= 65 years), Black race, high high-sensitivity C-reactive protein, and history of thromboembolism, cardiovascular disease, or diabetes. Univariate case-control analyses revealed that high hemoglobin rate of rise (>= 0.5 g/dL/week; odds ratio [OR] 2.09; 95% confidence interval [CI] 0.98-4.46) showed a trend towards increased risk of thromboembolic events before week 12, and high rate of hemoglobin decline was associated with events after week 12 (< - 0.5 g/dL/week; OR 3.73; 95% CI 1.68-8.27) as compared to stable hemoglobin levels (>= - 0.1 to < 0.1 g/dL/week). Multivariate case-control analyses showed that low last known hemoglobin level (< 10 g/dL: adjusted OR 1.91; 95% CI 1.04-3.50; vs >= 12 g/dL) and low last known transferrin saturation (TSAT < 10%: adjusted OR 3.78; 95% CI 1.71-8.39; vs >= 30%) before event onset were associated with events after week 12. In patients with last known TSAT < 30%, higher roxadustat dose was associated with thromboembolic events; however, no association was observed in those with TSAT >= 30%. Conclusions: Among various risk factors for thromboembolic events, it is reasonable to avoid a rapid increase and decline in hemoglobin levels as well as ensure TSAT >= 30%, rather than increasing the roxadustat dose.