Blood pressure in persons with haemophilia with a focus on haemophilia-specific risk factors

Persons with haemophilia (PWH) have a higher prevalence of hypertension compared to the general population, which cannot be explained entirely by the usual cardiovascular risk factors. Neutralizing antibodies (inhibitors) against clotting factors might have some relation to cardiovascular disease in PWH. However, whether inhibitors facilitate hypertension is unknown.

We investigated the relationship between hypertension/blood pressure and inhibitors in PWH. Additional goals were to determine the relationships with haemophilia type, race, and viral status.

Records were extracted retrospectively for PWH (age ≥18 years) between 2003 and 2014 from four Hemophilia Treatment Centers in North America and included demographics, weight, height, haemophilia type/severity, HCV and HIV infection status, hypertension, use of anti-hypertensive medications, and inhibitor status. We fitted semiparametric generalized additive models (GAMs) to describe adjusted curves of blood pressure (BP) against age.

Among 691 PWH, 534 had haemophilia A and 157 had haemophilia B, with a median age of 39 years (range 18 to 79). Forty-four PWH (6.5%) had a history of inhibitors, without evidence for a higher prevalence of hypertension or higher BP. A higher prevalence of hypertension and higher BP were noted for haemophilia A (vs. haemophilia B), coinfection with HCV/HIV (vs. uninfected), or moderate haemophilia (vs. severe haemophilia).

While there was no signal to suggest that a history of inhibitors is associated with hypertension, differences based on haemophilia type, severity, and viral infection status were identified, encouraging prospective investigations to better delineate haemophilia-specific risk factors for hypertension.