Cardiovascular comorbidity prevalence in males with haemophilia A

Date of ISAC Approval: 
07/02/2020
Lay Summary: 
The study aims to compare the frequency of cardiovascular diseases (diseases of the blood circulation and heart) between patients with haemophilia A and the general population. Hemophila A is a rare, genetic bleeding disorder, affecting usually males. During the last decades, life expectancy of patients with haemophilia A has improved dramatically. Now these patients are also affected by the presence of additional diseases of aging. The study will examine the coexistence of cardiovascular diseases, using a large healthcare database in the UK.
Technical Summary: 
Today, with the advent of modern treatment modalities , life-expectancy of patients with hemophilia (PWH) has improved dramatically and thus older PWH are not only affected by the comorbidities of hemophilia (arthropathy, consequences of viral infections), but also by the comorbidities associated with aging. However, contemporary population-based data allowing a direct comparison of haemophilia patients with age-matched non-hemophilia patients regarding cardiovascular comorbidity and risk factor profile are currently limited, and the results are inconsistent. The presently proposed study, using large population-based healthcare databases in the UK and the US, will allow such a direct comparison and thus generate more contextual data to describe the cardiovascular risk and risk factors in patients with haemophilia A. Primary outcomes will be the period prevalence of cardiovascular comorbidity (e.g. hypertension, diabetes mellitus, coronary heart disease, renal failure, atrial fibrillation and others) in the hemphilia A group compared to the non-hemophilia patients matched for categories of age, GP practice, year of cohort entry. As secondary outcomes overall mortality and cardiovascular mortality will be investigated. Statistics will be descriptive and explorative in nature. Period prevalence will be calculated, defined as: Proportion of the population with the specific outcome over the total study time period. Relative risk (prevalence ratio) for exposure group comparison including 95% confidence intervals, by dividing the period prevalence in the PWH cohort by the period prevalence in the comparison cohort (We will check if the available observation-time in the database for the hemophilia cohort and the non-hemophilia cohort is similar, if not, adjustments will be made). Stratifications into age-bands will be made. The following age-bands will be used: 0-30, 30-60 and >60 years of age. Mortality rate calculated as incidence rate using person-time will be calculated as secondary analysis: - Mortality using cardiovascular diagnosis 30 days before death as a proxy. - Mortality rate ratio and 95% Confidence Interval for exposure group comparison will be calculated.
Health Outcomes to be Measured: 
a. Arterial hypertension b. Diabetes mellitus (type I and II) c. Hypercholesterinemia d. Renal failure e. Coronary heart disease f. Myocardial infarction g. Atrial fibrillation h. Heart failure i. VTE j. TIA/ischemic stroke k. COPD l. Depression m. Sleep apnea syndrome n. HIV o. Hepatitis C p. BMI (in adults, <25 versus >25) highest value will be considered for individuals with several values available q. Smoking status (never versus smoking at any time) r. Overall mortality/cardiovascular mortality
Collaborators: 

Alexander Michel - Chief Investigator - Bayer AG
Alexander Michel - Corresponding Applicant - Bayer AG
Dr Ceri Hirst - Collaborator - Bayer AG
Dr Fang Xia - Collaborator - Bayer AG
Inga Bayh - Collaborator - Bayer AG
Marcela Rivera - Collaborator - Bayer AG