Despite a dramatic increase in the use of thrombolytic therapy for acute ischemic stroke, 25% of eligible patients still do not receive this treatment, according to data from a national registry (Messé SR, et al. Neurology. 2016;87:1565-1574).
Overall, 15,282 (25%) of the patients with acute ischemic stroke did not receive intravenous (IV) tissue plasminogen activator (tPA) between 2003 and 2011. However, the proportion of eligible patients with untreated acute stroke decreased from 55% in 2003 to 18% by the end of 2011.
Multiple factors correlated with failure to treat, including older age, sex (female vs male), race or ethnicity, type of hospital, and geographic location, reported Steven R. Messé, MD, Associate Professor of Neurology, Hospital of the University of Pennsylvania, Philadelphia, and colleagues.
“As has been reported previously, treatment at a primary stroke center is one of the strongest predictors of tPA use,” stated Dr Messé, MD, and colleagues. “Thus, to improve thrombolysis rates, continued development of systems of care for stroke should remain a high priority,” they added.
The demonstrated ability of IV tPA to improve outcomes in acute ischemic stroke has led to endorsement of its use in several clinical guidelines; the endorsement was followed by a dramatic increase in the use of IV tPA over the past decade. Nevertheless, recent studies showed that as many as 33% of eligible patients with acute ischemic stroke do not receive IV tPA.
The reasons for failure to treatment had not been well studied. The investigators hypothesized that a variety of patient- and hospital-specific factors predicted the use of tPA, including some potentially modifiable factors. To examine this issue, they reviewed trends in the use of IV tPA in hospitals participating in Get With The Guidelines (GWTG)-Stroke, a voluntary national registry and quality improvement initiative.
Get With The Guidelines-Stroke National Registry
Since the inception of GWTG-Stroke in 2003, more than 1800 hospitals have entered >2.5 million patients with stroke into the program’s database. Previous studies showed that patients enrolled in GWTG-Stroke were representative of the general population of patients with acute ischemic stroke in the United States, the investigators noted.
Dr Messé and colleagues queried the GWTG-Stroke database to identify all patients who arrived at a hospital within 2 hours of the onset of symptoms that were consistent with acute ischemic stroke. The search yielded 177,719 patients, 116,021 (65%) of whom had a documented contraindication to or warning for tPA use. Mild or rapidly improving symptoms accounted for a majority (51%) of the contraindications, followed by advanced patient age (7%); patient or family refusal (6%); and computed tomography (CT) findings of major infarct, intracerebral hemorrhage, or subarachnoid hemorrhage (6%).
The remaining 61,698 patients met the accepted criteria for IV tPA and formed the basis for data analysis. The GWTG-Stroke achievement measure calls for administration of IV tPA within 3 hours to patients who arrive at a hospital within 2 hours of symptom onset and do not have contraindications to thrombolytic therapy.
The data showed that 46,416 of the eligible patients received IV tPA within 3 hours of arrival. The 25% failure-to-treat rate represented the average for the study period, taking into account the 37% absolute reduction in the failure-to-treat rate from 2003-2005 to 2010-2011 (P <.0001).
To gain insight into factors associated with nontreatment of eligible patients with a documented National Institutes of Health (NIH) Stroke Scale score, the investigators performed a multivariate analysis, which yielded 11 patient-related predictors, including age >70 years (odds ratio [OR], 1.13; P <.0001), female sex (OR, 1.08; P = .008), black versus white race (OR, 1.26; P <.0001), other race versus white race (OR, 1.17; P = .0022), atrial fibrillation (OR, 1.15; P = .0001), prosthetic heart valve (OR, 1.77; P <.0001), diabetes (OR, 1.16; P <.0001), dyslipidemia (OR, 0.91; P = .005), peripheral vascular disease (OR, 1.21; P = .007), history of stroke or transient ischemic attack (OR, 1.40; P <.0001), and the use of antithrombotic agents (OR, 1.13; P = .0003).
Nonpatient factors that increased the likelihood of nontreatment with IV tPA included arrival during off-hours (OR, 1.12; P <.0001), increasing time from symptom onset to arrival (OR, 1.21; P <.0001 per 10-minute increase beyond 45 minutes), door to CT time >25 minutes (OR, 1.41; P <.0001 per 10-minute increase), percent NIH Stroke Scale score completed (OR, 1.07; P = .0001 per 10% increase), rural location (OR, 1.46; P = .02), midwest versus northeast location (OR, 2.06; P <.0001), and south versus northeast location (OR, 2.38; P <.0001).
Acknowledging the improvement in treatment rates with IV tPA, the researchers nonetheless called for continued diligence in educating patients with risk factors for stroke and their families about potential stroke symptoms, and the need to call for emergency medical services transportation whenever a stroke is suspected.