Mortality rates from acute stroke declined since introduction of stent retrievers

Since the introduction of stent retrievers in 2012 for the performance of mechanical thrombectomy in patients with acute stroke, overall and age-specific mortality rates have significantly declined in this patient population, researchers reported at the Society for NeuroInterventional Surgery Annual Meeting.

Srikanth Boddu, MSc, FRCR, MD, and colleagues evaluated data on the outcomes after interventional treatment of acute ischemic stroke in the United States between 2006 and 2007, 2008 and 2011, and in 2012. The data were collected from the Nationwide Inpatient Sample database, with the three time periods selected each representing different eras of device-based stroke treatment: after introduction of the Merci retriever system (Concentric Medical, 2006-2007); after introduction of the Penumbra system (Penumbra, Inc., 2008-2011); and after the introduction of stent retrievers (2012).

Boddu, an interventional neurologist at the Weill Cornell Brain and Spine Center in New York, and colleagues identified 723,327 admissions for acute stroke from 2006-2007, 737,125 from 2008-2011 and 738,490 during 2012. However, despite the increase in admissions over time, the mortality rate decreased during 2012 with IV tissue plasminogen activator (tPA; 6.7% vs. 8.2% in 2008-2011 and 9.3% in 2006-2007; P = .007), mechanical thrombectomy (17.1% vs. 19.3% and 25%; P < .0001) and a combination of the two strategies (24.3% vs. 33.2% and 27.4%, respectively; P < .0001).

Boddu and colleagues also observed a significantly higher rate of intracranial hemorrhage in 2012 compared with the other time periods across all treatment methods (P < .0001 for all comparisons).

Age-specific mortality also decreased significantly in 2012 compared with the other evaluated periods among patients aged 65 to 79 years (14.9% vs. 20.5% in 2008-2011 and 30.2% in 2006-2007; P < .0001) and those aged 80 years or older (20% vs. 25.8% and 26.3%, respectively; P < .0001). Mortality risk also declined for patients aged younger than 65 years between 2006-2007 and 2008-2011 (23.7% vs. 17.2%; P < .0001), but the difference between 2008-2011 and 2012 was not significant (17.2% vs. 17.4%; P = .07).

Similarly, risk for moderate-to-severe disability was significantly higher in 2012 among patients aged 65 years or older compared with the previous time periods, and researchers noted a significant increase in risk observed between 2006-2007 and 2008-2011 among patients aged younger than 65 years that was not presented between 2008-2011 and 2012.

“It is clear that the introduction of stent retrievers for stroke treatment has been a significant game-changer,” Boddu said in a press release. “Not only have these tools provided practitioners with new approaches to treatment, but we have also proven that innovation is worth the investment. With treatment advances, we are seeing increasing numbers of patients survive stroke.” – by Adam Taliercio

For more information:

Boddu S, et al. Presented at: Society of NeuroInterventional Surgery Annual Meeting; July 27-30, 2015; San Francisco.

Disclosure: The researchers report no relevant financial disclosures.