A Review of Long-term Efficacy by Different Therapeutic Approaches on Chinese Severe Haemophiliacs

Abstract Description

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Authors (including presenting author) :

Fong NFT(1)(2), Kho BCS(1), Lao WC(1), Chan, GCF(2)

Affiliation :

(1) Department of Medicine, Pamela Youde Nethersole Eastern Hospital, (2) Department of Paediatrics & Adolescent Medicine, LKS Faculty of Medicine, The University of Hong Kong

Introduction :

There is a lack of study reporting the comparisons of intermittent-dose or high-dose (primary and secondary) prophylaxis versus on-demand therapy of our local haemophilic population with moderate-to-severe diseases under the public health care system. The long-term efficacies of primary and secondary radiosynovectomy on them also remain elusive.

Objectives :

(1) Compare the efficacies of prophylaxis and on-demand therapy on reducing bleeding and preventing other complications of our local haemophiliacs, (2) Study the non-bleeding duration of recurrent haemarthrosis achieved by primary and secondary radiosynovectomy

Methodology :

Methodology: A retrospective, case-controlled, cross-sectional study was conducted to investigate the above issues. The study was divided into two parts - Part A and B. Part A compared the annualised bleeding rate (ABR) of patients on prophylaxis (n=21) versus on-demand treatment (n=5). Secondary outcomes were prevention of complications, e.g. haemophilia arthropathy and major bleeds. Part B investigated the mean interval of recurrent haemarthrosis after primary (1st) and secondary (2nd) radiosynovectomy (n=13 and n=5, respectively). Recurrent haemarthrosis was defined as more than 3 breakthrough joint bleeds within 2 months. It was an important indicator in reflecting the status of haemophilic arthropathy. It also suggests an annulment of previous radiosynovectomy necessitating another radiosynovectomy. Time-to-event analysis was presented by Kaplan-Meier curve.

Result & Outcome :

Results: Part A: A significant difference was found in ABR between prophylaxis and on-demand groups (4.7±4.8 vs 51.6±59.6 bleeds/year, 95% CI: 2.24-23.2, p=0.0002). The number needed to treat (NNT) of prophylaxis for haemophilic arthropathy was 4 with absolute risk reduction (ARR) of 26.7 % (95% CI: - 20.7%-74.1%). The NNT of prophylaxis for major bleeds was 5 with ARR of 23.8 % (95% CI: 5.6%-42%). Part B: The mean interval of a recurrent haemarthrosis after 1st radiosynovectomy was 23.1 ± 26.8 months, which was in line with our pre-set null hypothesis. However, recurrent benefit of 2nd radiosynovectomy was very transient and the interval of rebleeding was only 4.6 ± 3.04 months, which was remarkably shorter than expected. Conclusion: Our results were consistent with the literature. As expected, prophylaxis significantly reduced bleeding and prevented complications in severe haemophiliacs. Prophylaxis should become a standard practice in our local setting. The effect of 1st radiosynovectomy lasted for approximately 24 months but 2nd radiosynovectomy only lasted for 5 months which was much shorter than anticipated duration. Earlier intervention may yield a better result. Our results provided valuable reference for the haemophilia care in Hong Kong.