Mortality and causes of death in the Familial Intracranial Aneurysm study

Background Higher mortality for patients with aneurysmal subarachnoid haemorrhage has been reported. Aims In families with intracranial aneurysms, we sought to determine whether mortality among subjects with intracranial aneurysm (affected) was higher and related to rupture, compared with unaffected family members. Methods Subjects enrolled in the F amilial I ntracranial A neurysm protocol were contacted yearly and their status was obtained. If reported to be deceased, the cause of death was verified by available records. A C ox proportional hazards model was utilized to compare mortality rates. Results Of the 2794 subjects, 1073 were affected and 1721 were unaffected. There were 8525 person‐years of follow‐up (mean 3·05 ± 1·73 years) and 85 deaths. Age at study entry for the affected (58·4 ± 11·9 years) was significantly older ( P  < 0·0001) than for the unaffected (52·2 ± 16·1). After adjusting for age, the overall mortality rate for the affected subjects was not significantly different from that for the unaffected (Rate Ratio [RR] 1·26, 95% confidence interval 0·82–1·93, P  = 0·292). There was a strong effect modification due to age. The mortality rate ratio of the affected to the unaffected who were ≤60 years of age was RR  = 3·48 (95% confidence interval: 1·59–7·63, P  = 0·002), the rate for the affected subjects who were ≥60 was less than the rate for the unaffected ( RR  = 0·69, 95% confidence interval: 0·404–1·19, P  = 0·178). The affected who had ruptures had 2·62 times the mortality rate as those without ruptures (95% confidence interval 1·43–4·80, P  = 0·002). Conclusion The overall mortality was similar for the affected and unaffected subjects in this cohort. Among the affected only, those with ruptured intracranial aneurysm had a higher mortality rate than those without ruptured.