RESUMEN
BACKGROUND: Incidence, clinical course, and fatality of spontaneous subarachnoid haemorrhage (SAH) are evolving, with prevalence of risk factors diminishing, implementation of early detection programs and strategies for priority aneurysm exclusion, technical refinement towards less invasive procedures, and improvements in neurocritical care. Modern epidemiological and prognostic data are lacking, especially in southern European and Mediterranean populations. METHODS: A prospective multicentre observational study on SAH was held in Catalonia, Northeast Spain, 2020-2022 (HSACat project). All public tertiary hospitals participated in a common registry. Primary endpoints were functional outcomes (modified Rankin Scale, mRS) and mortality at 12-months. Secondary aims included epidemiological data, flux of patients between referral and tertiary hospitals, diagnostic and treatment delays, and in-hospital complications. RESULTS: Of 550 SAH cases reported in Catalonia (2020-2022), 474 had a complete registry for analysis. Death rate was 20.6% during hospital admission and 26.9% at one year. Good functional outcome (mRS 0-2) was observed in 63.4%, 70.1% and 76.0% at 3, 6 and 12 months. Age at presentation was lower in men, smokers, and hypertensives (p<0.05). The female:male ratio was 3:2, except in non-aneurysmal group. Time from onset to tertiary-hospital admission was longer in rural than metropolitan zones (7.0h vs 4.7h, p<0.01). Aneurysm occlusion in the first 72h was achieved in 83.3%; mainly endovascularly (77.5%) than microsurgically (19.3%). CONCLUSION: Even when most patients received timely aneurysmal treatment, rates of case fatality are considerably high. Data provided by the HSAcat project may have public health repercussions and be used to guide prevention programs and screening strategies.