Early Mortality in Paroxysmal Nocturnal Hemoglobinuria

Abstract

Objectives: The elevated mortality risk among patients with paroxysmal nocturnal hemoglobinuria (PNH) has been suggested to derive from a high risk of thromboembolism (TE); however, the risks of coexisting cardiovascular risk factors are not well described. We studied mortality associated with PNH taking comorbidity and treatment into account. Methods: Patients with PNH (n=115) were identified in the 1977-2016 Danish National Patient Register (DNPR). For each patient with PNH, we identified 50 age-and sex-matched general population comparators. Using the Kaplan-Meier estimator and Cox regression, we compared the overall survival of patients with comparators. Cumulative incidences were used to analyze the effects of comorbidity and the causes of death. Results: One-year survival among patients and comparators was 92.2% and 99.4%, and after 10 years, it was 68.4% and 85.8%, respectively. Early mortality was associated with older age, higher levels of comorbidity, and solid malignancies prior to PNH diagnosis. The leading causes of death were infections and associated hematological diseases. Patients with early mortality were less likely to have received treatment with eculizumab and/or warfarin. Cardiovascular risk factors were evenly distributed between patients and comparators at diagnosis. Conclusion: We conclude that early mortality in PNH is associated with older age, cardiovascular comorbidity, and hematological malignancies.