The HSACat Project: A Prospective Multicenter Observational Study of Spontaneous Subarachnoid Hemorrhage in Catalonia, Spain

Background: Incidence, clinical course, and fatality of spontaneous subarachnoid hemorrhage (SAH) are evolving, with prevalence of risk factors diminishing, implementation of early detection programs and strategies for priority aneurysm exclusion, technical refinement with 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 multicenter observational study on SAH was held in Catalonia, Northeast Spain, from 2020 to 2022 (HSACat project). All public tertiary hospitals participated in a common registry. Primary end points were functional outcomes (modified Rankin Scale) and mortality at 12 months. Secondary aims included epidemiological data, passage 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), a complete registry for analysis was available for 474. Death rate was 20.6% during hospital admission and 26.9% at 1 year. Good functional outcome (modified Rankin Scale score 0-2) was observed in 63.4%, 70.1%, and 76.0% at 3, 6, and 12 months. Age at presentation was younger in men, patients who smoked, and patients with hypertension (P < 0.05). The female-to-male ratio was 3:2 except in the nonaneurysmal group. Time from onset to tertiary hospital admission was longer in rural than in metropolitan areas (7.0 hours vs. 4.7 hours, P < 0.01). Aneurysm occlusion in the first 72 hours was achieved in 83.3%; mainly endovascularly (77.5%) followed by microsurgically (19.3%).

Conclusions: Even when most patients received timely aneurysm treatment, case fatality rates were considerably high. Data provided by the HSACat project may have public health effects and be used to guide prevention programs and screening strategies.