Acute Ischemic Stroke Care: New Insights From Two Large Database Studies

Two recent nationwide database analyses have yielded interesting insights for the management of patients with acute ischemic stroke. One showed that hospital transfer is associated with poorer outcomes, while the other demonstrated that stroke care since the launch of the “Target: Stroke” quality initiative by the American Heart Association has been associated with faster thrombolytic treatment and slightly lower one-year readmission rates.

The studies, both of which were led by Cleveland Clinic researchers, are briefly profiled below.

Hospital transfer and stroke outcomes

The first study, published by Cleveland Clinic investigators in the Journal of Stroke and Cerebrovascular Diseases (29[12] 2020 Dec:105331), compared outcomes among Medicare beneficiaries with ischemic stroke according to whether they were transferred to another hospital or directly admitted from a hospital emergency department (ED).

“This study aimed to examine patterns of interhospital transfer for ischemic stroke, with the goal of further optimizing our nation’s stroke system of care,” says senior author Ken Uchino, MD, a stroke neurologist and Head of Research and Education in Cleveland Clinic’s Cerebrovascular Center. “We found significant disparity of stroke care across the United States, in terms of both hospital capability and outcomes.”

Study design and findings.The analysis focused on Medicare fee-for-service beneficiaries aged 65 or older hospitalized during 2012 who had a primary discharge diagnosis of ischemic stroke. Among 312,367 admissions, 5.7% of patients underwent interhospital transfer. This threshold was used to classify hospitals according to their stroke patient transfer status, as follows:

• Receiving hospitals (n = 411), i.e., those where more than 5.7% of admissions were transferred in and less than 5.7% were transferred out
• Sending hospitals (n = 559), i.e., those where less than 5.7% of admissions were transferred in and more than 5.7% were transferred out
• Low-transfer hospitals (n = 1,863) i.e., those where transfers in and out were both less than 5.7% of admissions
• High-transfer hospitals (n = 43) i.e., those where transfers in and out were both more than 5.7% of admissions

Receiving hospitals tended to be significantly larger (by median bed number), more likely to be a certified stroke center and less likely to be located in a rural area.

The study yielded the following main findings:

• Receiving hospitals had comparable mortality at 30 days (10% vs. 10%) and one year (23% vs. 24%) for transfer-in patients and ED admissions, respectively.
• Sending hospitals had higher mortality for transfer-out patients than for ED admissions at 30 days (14% vs. 11%) and one year (30% vs. 27%).
• Low-transfer hospitals had higher mortality for transfer-in and transfer-out patients than for ED admissions at 30 days (13% vs. 10%) and one year (28% vs. 25%).

The researchers concluded that Medicare beneficiaries with ischemic stroke who are transferred to another hospital tend to have worse outcomes than those directly admitted from a hospital ED. “It’s possible that the differences in outcomes can be attributed to sicker patients being transferred,” says Dr. Uchino. “But this analysis highlights the need to improve standardized stroke care to address treatment gaps between our nation’s hospitals.”

Impact of ‘Target: Stroke’ on treatment time and one-year outcomes

The second study, published in Circulation: Cardiovascular Quality and Outcomes (2020 Dec; 13[12]:e007150), analyzed records from two linked databases — the Get With The Guidelines–Stroke national registry for stroke quality improvement and the Medicare fee-for-service claims database. Its aim was to assess the impact of the 2010 launch of Target: Stroke, a national quality initiative of the American Heart Association, on thrombolytic treatment time and outcomes at one year.

“This is the first study to evaluate long-term outcomes with Target: Stroke,” notes Shumei Man, MD, PhD, Medical Director of the Thrombectomy-Capable Stroke Center at Cleveland Clinic Fairview Hospital and first author on the study’s multicenter author team.

Study design and findings. The analysis identified 42,053 Medicare beneficiaries aged 65 or older who received intravenous thrombolytic therapy within 4.5 hours of symptom onset from Get With The Guidelines–Stroke participating hospitals from January 2006 through December 2014. Pre- and post-intervention cohorts (n = 10,804 and 31,249, respectively) were defined as receiving treatment either before or after January 2010, when Target: Stroke was initiated.

Study findings included the following differences between the pre- and post-intervention groups:

• Median door-to-needle times decreased from 80 minutes to 68 minutes (P < 0.001).
• The proportion of patients receiving thrombolytic therapy within 45 minutes increased from 9.6% to 17.1%; the proportion receiving it within 60 minutes rose from 24.8% to 40.6% (P < 0.001 for both).
• The readmission rate at one year decreased from 44.1% to 40.1% (hazard ratio [HR] = 0.91; 95% CI, 0.88-0.95).
• The cardiovascular readmission rate at one year decreased from 22.9% to 19.7% (HR = 0.85; 95% CI, 0.80-0.89).
• All-cause mortality at one year decreased from 36.9% to 35.2% (HR = 0.98; 95% CI; 0.94-1.02). This decline was attenuated after risk adjustment.

“We found substantial shortening of treatment time with thrombolytic therapy with the advent of Target: Stroke,” observes Dr. Man. “This was accompanied by modest improvements in clinical outcomes — specifically in all-cause and cardiovascular readmissions — at one year. These results support more intensive and widespread implementation of the strategies provided by the Target: Stroke quality initiative.”