Abstract WP25: Trends in the Use of Intravenous tPA and Mechanical Thrombectomy [MT] Among Elderly Medicare Beneficiaries Hospitalized for Acute Ischemic Stroke

Abstract

Objective: Early treatment with intravenous tissue plasminogen activator (tPA) followed by mechanical thrombectomy [MT] is the new standard of care for stroke patients with proximal arterial occlusion. We examined trends in the use of tPA and MT among black and white Medicare beneficiaries with stroke. Methods: We used de-identified data for Humana Medicare beneficiaries age >=65 to identify admissions for stroke during January 2009-March 2017 with primary diagnosis of ischemic stroke. Outcomes included IV tPA and MT identified by CPT, ICD-9, and ICD-10 procedure codes. Additional patient characteristics included demographics, comorbid conditions based on diagnosis codes prior to the stroke, and medication use from pharmacy claims. Logistic regression was used to evaluate the trends and racial differences in the use of IV tPA and MT while controlling for patient characteristics. Results: We identified 12,641 and 81,100 stroke admissions for black and white patients, respectively. Blacks were younger and more likely to have previous stroke, while white patients were more likely to have atrial fibrillation and use anticoagulants. Overall, 7558 (8.1%) received tPA during or within 1 day of stroke admission and 1533 (1.6%) underwent MT. The proportion of admissions receiving tPA increased from 5.3% in 2009-2010 to 9.9% in 2015-2016 among white patients, and from 5.7% to 9.9% among black patients. The proportion who underwent MT increased from 0.6% to 2.4% among whites, and from 0.5% to 2.5% among black patients. In multivariable logistic regression, the relative increase in tPA use over the observation period was 1.3 times greater for white compared to black patients (Odds Ratio [OR] for 2015-2016 relative to 2009-2010 = 2.01 [p<.001] for white patients and 1.55 [p<.001] for black patients). In contrast, the relative increase in MT use was nearly 2 times greater for black compared to white patients (OR for 2015-2016 relative to 2009-2010 = 3.90 [p<.001] for black patients and 2.01 [p<.001] for white patients). Conclusions: We did not find evidence of racial differences in the use of tPA or MT among black and white patients with acute ischemic stroke. Overall there was a dramatic increase in the use of recommended therapies over the 9-year observation period.