Subarachnoid haemorrhage and intracranial aneurysms in Greenland in the period 2018-2021: incidence, outcome and familial disposition

Subarachnoid haemorrhages (SAH) caused by rupture of intracranial aneurysms (IA) are a severe condition. Earlier studies found a higher incidence of SAH in Greenlandic patients compared to Danish patients, with familial aggregation also higher in Greenland. However, updated data is lacking. To investigate the contemporary incidence, outcome, and familial disposition of SAH/IA in Greenlandic patients in 2018-2021. Greenlandic patients diagnosed with ruptured or unruptured IA (UIA) during 2018-2021 were included. Data was obtained from patient files, x-ray department, and discharge registry. Incidence rates were estimated as cases/100,000/year. Direct age-standardised incidence rates were calculated using WHO 2000-2025 as standards. Of 30 SAH patients, 20 (66.7%) were females, 10 (33.3%) males. Of 36 UIA patients, 27 (75.0%) were females, 9 (25.0%) males. For SAH, crude incidence was 13.4/100,000/year, age-standardised incidence was 10.8/100,000/year. Familial history was observed in 30.0% of SAH patients. 5 patients (16.7%) died before treatment, 28-day case-fatality rate (CFR) for all patients was 23.3%. Overall and age-standardised incidence rates were similar to previous studies but higher among females and compared to neighbouring countries. A high occurrence of familial history was reported. SAH remains a serious condition in Greenland, as evidenced by five fatalities before treatment was administered.