Dec 28, 2021

Results of a recently published study suggest that intense physical activities, particularly those that include a high collision-risk, can increase bleeding risk in individuals with severe or moderately severe hemophilia A. Investigators also found that increasing the time between the administration of factor (FVIII) and physical activity also heightened bleeding risk.

The study, “A Prospective Observational Study of Antihemophilic Factor (Recombinant) Prophylaxis Related to Physical Activity Levels in Patients with Hemophilia A in the United States (SPACE),” was published in the Journal of Blood Medicine. SPACE was a six-month, multicenter study designed to assess the link between physical activity levels, FVIII infusion, and occurrence of bleeding episodes.

54 hemophilia A patients (mean age of 23.7; range 11–58 years) were enrolled in SPACE, each of whom received a customized eDiary smartphone application and a wearable activity tracker to record their physical activity, intervals between infusions, and bleeding events over the six-month study period. These patients were receiving a recombinant FVIII product (Advate, Takeda). Physical activity risks were ranked using the National Hemophilia Foundation’s * Playing It Safe: Bleeding Disorders, Sports, and Exercise, with ratings ranging from low risk (1) to moderate risk (2) to high risk (3).

Participants had a mean of five bleeding episodes in the six months leading up to their trial participation. Prophylaxis was their most frequent treatment choice (47 patients), followed by on-demand treatment in seven patients.

A total of 4,980 intervals were recorded between FVIII infusion and a subsequent physical activity (morning, noon, or night), with the majority of infusions administered approximately 24 hours or more before starting a physical activity (64.7%). Most of the intervals assessed were considered low-risk activities (75.5%), with 3.9% considered of high risk.

In terms of bleeding event occurrence, 17 of the 54 patients (31.5%) reported no bleeding episodes, while the remaining 37 experienced 185 bleeding events.

Amongst participants on prophylaxis, investigators observed a mean of 3.02 bleeds per patient; of those 1.26 were reported as activity related. In the patients receiving on-demand treatment, 6.14 bleeds were reported per person, of which 2.29 were deemed activity related. At the conclusion of SPACE, the mean annualized bleeding rate (ABR) for all bleeds was 8.14. When broken down by treatment regimen, ABR was significantly higher among patients receiving on-demand therapy versus those on prophylaxis, at 19.14 vs. 6.92 respectively. The occurrence of joint bleeds followed this pattern with 15.59 in the on-demand therapy group versus 2.81 in the prophylaxis group. The overall risk of bleeding due to physical activity “tended to increase commensurately with physical activities classified as higher risk,” the researchers wrote.

No significant association was observed between bleeds recorded in the eDiary as activity-related and timing of the last FVIII infusion prior to the start of physical activity. However, a longer time between a last FVIII infusion and an activity’s start — 24 hours or less, or more than 24 hours — were associated with a higher risk of spontaneous bleeds.

Further, factor “infusion was timed more closely to physical activity and occurred more frequently among patients engaging in higher-risk activities, although 60% of infusion intervals for level 2.5–3 activities exceeded 24 hours,” explained the authors. “Together, these findings suggest that less than half of patients adjusted [their factor] infusion timing for higher-risk physical activities.”
Overall, the findings suggest that activities associated with a high risk of collision lead to an increased risk of bleeding. “Further investigation is warranted to explore potential benefits of FVIII infusion timing to reduce the risks of activity-related occurrence of bleeding,” concluded the researchers.

Additional Resources

*Access Playing It Safe in both English and Spanish:

Playing It Safe: Bleeding Disorders, Sports, and Exercise
Jugando a lo Seguro: Trastornos Hemorrágicos, Deportes y Ejercicio

Read the full article, “A Prospective Observational Study of Antihemophilic Factor (Recombinant) Prophylaxis Related to Physical Activity Levels in Patients with Hemophilia A in the United States (SPACE).”

For more information on physical activity, bleeding disorders, and other topics contact HANDI, NHF’s Information Resource Center.

Source: Hemophilia News Today, December 13, 2021