Mild Haemophilia A Without Inhibitor Clinical Trial
Official title:
DDAVP vs Exercise in Patients With Mild Hemophilia A - Which is Better and do They Work Synergistically in Improving Hemostasis?
Individuals with mild hemophilia A (MHA) bleed infrequently but can in the setting of trauma which often is when participating in sports/exercise. Although both exercise and DDAVP (desmopressin) can raise Factor 8/Von Willebrand Factor (FVIII/VWF levels), it is not clear whether the pathophysiological mechanism is the same. Consequently it is not known if DDAVP and exercise would have additive effects in raising FVIII:C and VWF levels or if one would one negate the effect of the other. The aim of this 2 center (Sickkids and Columbus, Ohio), prospective, cross-over design study is to compare the impact of exercise vs. DDAVP on hemostasis in patients with MHA and also to investigate the impact of sequentially administering these interventions on their hemostatic indices.
Persons with mild hemophilia A (MHA) (defined as having a FVIII level of >5% to ≈40%) bleed
infrequently but can in the setting of trauma which can often is in the context of
participating in sports/exercise. FVIII levels temporarily rise with stress, exercise and
with DDAVP (1-desamino-8-D-arginine vasopressin, desmopressin). In the case of DDAVP, the
Hospital for Sick Children (SickKids) Hemophilia Team and others have shown that FVIII and
VWF levels rise by 2-4 fold with DDAVP. Consequently many persons with MHA in an attempt to
reduce their risk of bleeding take intranasal (IN) DDAVP prior to sports activities/exercise.
IN DDAVP is reasonably expensive ($300/bottle of Octostim® in Canada and $700/bottle of
Stimate® in USA), requires fluid restriction, and may be associated with nausea, vomiting,
seizures and tachyphylaxis.
Recently, our group completed a pilot/feasibility study to evaluate the impact of a
prescribed, moderate intensity aerobic exercise regimen on hemostatic indices in 30 children
with hemophilia A [HA] or B [HB] (all severities) and documented a significant improvement in
multiple coagulation parameters (platelet count, FVIII:C and von Willebrand factor [VWF])
with exercise. This improvement was particularly pronounced in 13 post-adolescent males with
mild-moderate HA. In this sub-cohort, we noted a mean 2.3 fold increase in FVIII:C
immediately after exercise, which remained significantly elevated at 1.9 fold,1 hour after
completion of exercise
These changes in hemostatic variables associated with aerobic exercise may be protective
against bleeding, and may negate the need to administer IN DDAVP immediately prior to sports
participation.
Although both exercise and DDAVP can raise FVIII/VWF levels, it is not clear whether the
pathophysiological mechanism in which they do this is the same. Consequently it is not known
if DDAVP and exercise would augment each other's effects in raising FVIII:C and VWF levels or
if one would one negate the effect of the other. Herein, we propose a prospective,
interventional study of exercise vs IN DDAVP in 40-50 post adolescent (13-21 yr) males with
MHA to compare their impact on hemostasis and also to investigate the impact of sequentially
administering these interventions on hemostatic indices.
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