Haemophilia protects against ischaemic heart disease: a study of risk factors

Abstract

Sununary.We previously reported that mortality due to ischaemic heart disease was lower in haemophilia patients than in the general male population. To support the hypothesis that this could be attributed to a protective effect of the clotting defect in haemophilia and not to differences in cardiovascular risk factors, we performed a second study. We examined 95 haemophilia patients for the presence of major risk factors for ischaemic heart disease and compared their risk factor profile with the data of epidemiologic surveys of the general Dutch population.Haemophilia patients had on average higher blood pressures than the comparison population, were more often hypertensive and used antihypertensive drugs twice äs often.The mean serum cholesterol level of the patients was markedly lower than in the comparison population (4-8 versus 5-6 mmol/1, 95% confidence interval of the difference: 0-5-Mmmol/l).The risk factors were weighted into one theoretical risk raüo for ischaemic heart disease by application of logistic regression coefficients. The theoretical risk ratio based on the risk factor profile was 0-78. This risk ratio can only explain a moderate reduction in the incidence of ischaemic heart disease, much smaller than the mortality ratio of 0-20 we reported previously. Therefore these data support the hypothesis of a direct protective effect of haemophilia on the development of ischaemic heart disease.

Decreased mortality of ischaemic heart disease among carriers of haemophilia

“…Furthermore, in a previous study we noted that the risk profile for Cardiovascular disease in patients with haemophilia does not differ greatly from that in the general male population. 27 Our results accord with those of other studies in which decreased coagulability has been associated with a protective effect against myocardial infarction. Such an effect has also been reported in patients with haemophilia, 27 and in individuals with blood group O compared with non-O (group O is accompanied by lower concentrations of von Willebrand factor and factor VIII).…”

Prevalence and risk factors for heart disease among males with hemophilia

“…Rosendaal found no relationship between cardiovascular risk factors, such as hypertension and elevated triglycerides, and IHD in the Dutch hemophilic population and used these data to support the hypothesis that the low incidence of IHD in this population was directly attributable to the coagulation defect [5]. In our study, persons with hemophilia with IHD were more likely to be hypertensive, have hyperlipidemia and were more likely to be diabetic than those without IHD.…”

“…On the other hand, those with angina, hypercholesterolemia, and other risk factors such as hypertension were probably less likely to have been admitted and, therefore, more likely to have been missed by our surveillance. In fact, at least one study has reported a higher prevalence of hypertension in a hemophilia cohort compared to a control population [5].…”

“…None of the hemophilia patients in the Dutch study of heart disease risk factors had overt evidence of IHD, but the number of persons studied was small [5]. De Paz and co-workers [18] reported that 9 of 371 moderate and severe hemophilia patients in Spain had IHD, a prevalence of 2.4%.…”

“…These findings have been interpreted as providing evidence that the hypocoagulable state offers protection from the thrombotic event that precipitates infarction. An alternative explanation involving lower prevalence of cardiovascular risk factors among persons with hemophilia was examined in a study by Rosendaal et al who found that the difference in risk factors could account for only a fraction of the decreased risk observed among Dutch hemophiliacs [5].…”