Mechanical Thrombectomy in Acute Ischemic Stroke Patients Performed Within and Outside Clinical Trials in the United States

BACKGROUND: A better understanding of differences in outcomes of mechanical thrombectomy performed within and outside clinical trials will assist in optimal implementation of the procedure for acute ischemic stroke patients in general practice. OBJECTIVE: To identify differences in demographic and clinical characteristics and outcomes related to mechanical thrombectomy in patients treated within clinical trials and those treated outside clinical trials in a large national cohort. METHODS: We compared the patient characteristics and associated in-hospital outcomes of mechanical thrombectomy in acute ischemic stroke patients performed within and outside clinical trials using the Nationwide Inpatient Sample from 2013 to 2015. We analyzed in-hospital mortality (primary outcome) and moderate to severe disability (secondary outcome) based on discharge disposition after adjusting for potential confounders. RESULTS: Of 23375 patients who underwent mechanical thrombectomy, 430 (1.8%) underwent the procedure as part of a clinical trial. After adjusting for age, gender, and the teaching status of the hospital, patients treated within a clinical trial had lower rates of in-hospital mortality (odds ratio [OR] 0.14; 95% CI .03 to .71; P < .001). Among patients discharged alive, the rate of moderate to severe disability (OR .43; 95% CI .26 to .71; P < .001) was lower among those patients treated within a clinical trial. There was no difference in odds of post-thrombectomy intracerebral or subarachnoid hemorrhage between the two groups. CONCLUSION: Mechanical thrombectomy performed as part of clinical trials was associated with lower rates of in-hospital mortality and lower rates of moderate to severe disability compared with those performed outside clinical trials.