Nitisinone Attenuates Aortic Stenosis Disease Progression in Patients with Alkaptonuria: An Analysis of the SONIA 2 Study

Background and Aim: Alkaptonuria (AKU) is a rare metabolic disorder characterised by the accumulation of homogentisic acid (HGA). Deposition of HGA in the aortic valve leading to progressive aortic stenosis is a serious complication. Nitisinone has been shown to improve morbidity and slow disease progression in AKU but the effects of this treatment on aortic stenosis progression have not yet been described. This review extrapolated from the data set of SONIA 2, a 4-year multi-centre randomised controlled trial investigating the effect of nitisinone on AKU disease activity, but specifically examined measures of aortic stenosis disease progression. Methods: Data were obtained from echocardiograms performed on 138 patients over 48 months of follow-up. A linear mixed effects regression model was used to ascertain the difference in the maximal trans-aortic valve pressure gradient (Pmax) at baseline and 48 months between the treatment and control groups. Results: At baseline, 18/138 patients (13.0%) had aortic stenosis of varying degrees of severity and 25/138 (18.1%) had aortic sclerosis. The difference in Pmax between the control (N=69) and treatment (N=69) groups at baseline was 0.063mmHg [95% CI: -0.054mmHg to 0.18mmHg) and did not reach statistical significance (p=0.23). At the end of the 4-year treatment period, the difference in Pmax was 0.10mmHg [95% CI: -0.0007mmHg to 0.20mmHg] and was statistically significant (p=0.05). Conclusion: Nitisinone slowed progression of aortic stenosis in patients with AKU. This supports the argument for timely initiation of nitisinone to reduce the incidence and severity of aortic valvular disease in AKU patients. Information & Authors Information Version history Copyright This work is licensed under a Non Exclusive No Reuse License.

Authors Metrics & Citations Metrics Article Usage 242views 129downloads Citations Download citation Callum Bruce, Priyanka Meenamkuzhy-Hariharan, Shahdat Hussain, et al. Nitisinone Attenuates Aortic Stenosis Disease Progression in Patients with Alkaptonuria: An Analysis of the SONIA 2 Study. Authorea. 25 November 2024. DOI: https://doi.org/10.22541/au.173253095.53989775/v1 DOI: https://doi.org/10.22541/au.173253095.53989775/v1 If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download. For more information or tips please see 'Downloading to a citation manager' in the Help menu.