Time Trends in Outcomes After Aneurysmal Subarachnoid Hemorrhage Over the Past 30 Years

Objective: To analyze trends in mortality rates, functional outcomes, and treatment in patients with aneurysmal subarachnoid hemorrhage (aSAH) over the past 3 decades. Patients and Methods: We conducted a retrospective review of consecutive patients with aSAH treated at Mayo Clinic in Rochester, Minnesota, between January 1, 1985, and December 31, 2014. Results: A total of 1173 patients identified were grouped by decade of treatment: 1985 to 1994, n=274; 1995 to 2004, n=461; and 2005 to 2014, n=438. Overall, the use of endovascular techniques increased progressively from 5.1% (14) in 1985 to 1994 to 65.5% (287) in 2005 to 2014. This corresponded to a progressive decrease in the rate of clipping from 78.8% (216) in 1985 to 2004 to 21.5% (94) in 2005 to 2014 (P<.001). The percentage of patients admitted with poor clinical grade also increased from 22.3% (61) in 1985 to 1994 to 24.1% (111) in 1995 to 2004 and 29.5% (129) in 2005 to 2014 (P=.06). The in-hospital mortality rate decreased from 22.6% (62) in 1985 to 1994 to 16.3% (75) in 1995 to 2004 and remained relatively constant at 16.7% (73) in 2005 to 2014. Good functional outcome at 3- to 6-month follow-up improved significantly from 64.8% (173) in 1985 to 1994 to 72% (332) in 1995 to 2004 and 78.8% (345) in 2005 to 2014 (P<.001). Conclusion: Outcomes in patients with aSAH have markedly improved over the past 3 decades, in terms of both in-hospital survival and functional recovery of survivors. Higher rates of endovascular coiling over time paralleled these improvements in clinical outcomes. More detailed investigation is necessary to determine whether this or other factors may directly explain the favorable trends in survival and functional recovery over time.