Congenital FVIII/IX or VWF Deficiency Does Confer a Lower Rate of Myocardial Infarction-Related Mortality Despite Decreased Cardiovascular Interventions

Introduction:

Patients with common inherited bleeding disorders (IBDs) including hemophilia and von Willebrand disease (VWD) are at risk of coronary artery disease (CAD) as they age, albeit lower than the general population. Intuitively, these patients would appear to have a higher mortality rate given an increased risk of hemorrhagic complications and/or possibly cardiovascular complications from undertreatment with antithrombotic agents and/or procedures.

Methods:

Data from National Hospital Discharge Survey (NHDS) from 2001-2010 were analyzed using diagnosis codes (ICD 9) to identify patients with hemophilia, VWD and myocardial infarction (MI). Demographics and discharge information were compared amongst patients who had an MI with and without these coagulopathies, using chi-squared tests, Fisher's exact tests, and linear regressions. All tests were adjusted for survey design with sampling weights. Yearly rates of MI were compared between patients with and without these coagulopathies. All analyses were performed in STATA 12.0.

Results:

During the years 2001-2010, about 0.2 million patients (weighted data) were discharged with IBD i.e. hemophilia and VWD. Among them, the incidence of MI was 0.26% in hemophilia and 1.61% in VWD patients. Hemophilia patients were more likely to be men (76.9% vs 56.2%) and Caucasians (66% vs 65%) while VWD patients were more likely to be younger (67 vs 69 years), women (52% vs 44%) and Caucasians (66% vs 65%) compared to the normal population (all p-values <0.001).

Compared to non-bleeding disorder patients, the patients with VWD and hemophilia had shorter duration of hospital stay and lower in-hospital mortality compared to normal population.

Furthermore, VWD patients were less likely to undergo coronary artery bypass graft (CABG) (2.0% vs 30.4%), coronary angiogram (14.5% vs 29.5%) and systemic thrombolysis (0.0% vs 1.1%) for the treatment of MI whereas patients with hemophilia are less likely to undergo CABG (11.1% vs 30.4%) but more likely to undergo coronary angiogram (41.2% vs 29.5%) (all p-values <0.001). They are also less likely to undergo systemic thrombolysis (0.0% vs 1.1%) but the difference was not statistically significant (p-value 0.121).

On the other hand, hemophilia patients with MI had a higher prevalence of the following complications: cardiogenic shock (26% vs 2.3%), pneumonia (32.9% vs 8.2%), respiratory failure (25.9% vs 9%) and intubation (25.9% vs 7%) compared to MI patients without hemophilia (all p-values <0.001). While VWD patients with MI had comparatively better outcomes in terms of lower risk of cardiogenic shock (0.0% vs 2.3%), pneumonia (0.8% vs 8.2%), respiratory failure (0.0% vs 9%), and GI bleeding (0.0 vs 1.6%) compared to MI patients without VWD (all p-values <0.001), they did have increased prevalence of acute kidney injury (50.1% vs 9.0%, p-value <0.001).

Conclusion:

Although patients with coagulopathic disorders are historically thought to have a lower risk of MI, they can be at an increased risk of complications. But, nonetheless, they have a lower risk of in-hospital mortality which may be due to the putative protective effect of lower levels of FVIII/IX or VWF. These patients, in general, are less likely to receive therapeutic interventions. Further prospective study is needed in order to confirm and better understand the discordance of a lower in-patient mortality in inherited bleeding disorder patients despite a decrease in some cardiac interventions and an increase in some non-cardiac complications