Background/Aims: Prior reports show the occurrence of Moyamoya angiopathy (MMA) in the ethnically diverse Auckland region, but little is known about the sociodemographic burden of the condition and clinical outcomes. We sought to determine the age, sex and disease prevalence stratified by ethnicity, and patient outcomes in adults residing in Auckland (population 1.7 million). We also sought to determine associations with the outcomes of cerebrovascular events, and functional independence following diagnosis.
Methods: We searched hospital medical records and radiology reports in the period 1998-2024 for the region using relevant ICD codes and the word ‘moyamoya’. We used descriptive statistics and local population data to calculate prevalence. Statistical tests of association were performed for continuous, categorical, and time-to-event data for the prespecified outcomes.
Results: We identified 98 patients with a total of 713 patient-years of follow-up. The mean age at diagnosis was 38 years (SD 17.2) and females outnumbered males by 3:1. The point prevalence ranged from 1.8/100,000 in Europeans, 5.2/100,000 in Asians, 6.4/100,000 in Māori and 9.5/100,000 in Pacific peoples. 39% had a cerebrovascular event at a median of 641.5 days (IQR 109-1639) following diagnosis. Two-thirds of the overall cohort were independent on follow-up (mRS 0-2) and 17% had died. In the multivariate analysis, factors associated with loss of independence included cerebrovascular events during follow-up, and severe hypoperfusion on imaging (p<0.05).
Conclusion: In this New Zealand-based study, we found a wide ethnic variation in the prevalence of MMA and an elevated early risk of cerebrovascular events following diagnosis.