Effect of Hispanic Status in Mechanical Thrombectomy Outcomes After Ischemic Stroke: Insights From STAR
Background and Purpose:
Epidemiological studies have shown racial and ethnic minorities to have higher stroke risk and worse outcomes than non-Hispanic Whites. In this cohort study, we analyzed the STAR (Stroke Thrombectomy and Aneurysm Registry) database, a multi-institutional database of patients who underwent mechanical thrombectomy for acute large vessel occlusion stroke to determine the relationship between mechanical thrombectomy outcomes and race.
Patients who underwent mechanical thrombectomy between January 2017 and May 2020 were analyzed. Data included baseline characteristics, vascular risk factors, complications, and long-term outcomes. Functional outcomes were assessed with respect to Hispanic status delineated as non-Hispanic White (NHW), non-Hispanic Black (NHB), or Hispanic patients. Multivariate analysis was performed to identify variables associated with unfavorable outcome or modified Rankin Scale ≥3 at 90 days.
Records of 2115 patients from the registry were analyzed. Median age of Hispanic patients undergoing mechanical thrombectomy was 60 years (72–84), compared with 63 years (54–74) for NHB, and 71 years (60–80) for NHW patients (P<0.001). Hispanic patients had a higher incidence of diabetes (41%; P<0.001) and hypertension (82%; P<0.001) compared with NHW and NHB patients. Median procedure time was shorter in Hispanics (36 minutes) compared to NHB (39 minutes) and NHW (44 minutes) patients (P<0.001). In multivariate analysis, Hispanic patients were less likely to have favorable outcome (odds ratio, 0.502 [95% CI, 0.263–0.959]), controlling for other significant predictors (age, admission National Institutes Health Stroke Scale, onset to groin time, number of attempts, procedure time).
Hispanic patients are less likely to have favorable outcome at 90 days following mechanical thrombectomy compared to NHW or NHB patients. Further prospective studies are required to validate our findings.
Racial and ethnic minorities currently constitute 39.9% of the population in the United States with Hispanic or Latino Americans representing the largest minority group at 18%, followed by Black Americans comprising 13.4% of the population.1 Previous studies have demonstrated racial and ethnic disparities in stroke including higher incidences of stroke and worse outcomes in Hispanic and Black populations.2 Furthermore, non-Hispanic Black (NHB) and Hispanic patients have been less likely to receive mechanical thrombectomy (MT) than non-Hispanic White (NHW) patients.3 However, little information has been presented on disparities in stroke outcomes after MT. In this study, we use the prospective multicenter STAR (Stroke Thrombectomy and Aneurysm Registry) database to examine the effect of Hispanic status on long-term outcomes in patients who underwent MT.
The data that support the findings of this study are available from the study’s registry upon reasonable request. We used data from prospectively maintained databases of 10 thrombectomy-capable stroke centers in North America and Europe participating in STAR, after approval by local Institutional Review Boards at each participating institution. Informed consent was waived by each institution’s Institutional Review Board given the retrospective nature of the study.
Collected data included self-reported demographics, risk factors, admission National Institutes Health Stroke Scale, whether patients received intravenous tPA (alteplase), time from symptom onset to groin puncture, procedural times, thrombectomy techniques, number of attempts, complication rates, and rate of symptomatic hemorrhage. Symptomatic hemorrhage was defined using ECAS III (European Cooperative Acute Stroke Study) definition (worsening of ≥4 points in National Institutes Health Stroke Scale attributed to hemorrhagic transformation), and favorable long-term functional outcome was defined as 90-day modified Rankin Scale score of 0 to 2. Secondary prevention therapies were administered at the discretion of each study center.
Between-group analysis was conducted using χ2 test with corresponding P values provided for categorical variables. Continuous variables were compared using independent-samples t test. Factors with a P<0.15 were included in final multivariate model. Final multivariate model was built using logistic regression for primary analysis of favorable outcome. Variables were excluded from the model if removal resulted in no significant difference in the interpretation of other variables. Confounding was assessed through substratification and further modeling as needed. P<0.05 was considered statistically significant. Analyses were conducted using SPSS (version 24, IBM).
RECORD (Reporting of Studies Conducted Using Observational Routinely-Collected Data) guideline checklist and illustrative flow diagram are provided as Data Supplement.
Nonrace Baseline Demographics
Records of 2115 patients from the registry were analyzed. One thousand five hundred thirty-five (73%) were identified as NHW, 295 (14%) NHB, and 285 (13%) Hispanic. The relative proportion of patients enrolled at each study center is given in Table 1. The median age of Hispanic patients undergoing MT was 60 years old (72–84), compared with 63 years old (54–74) for NHB, and 71 years old (60–80) for NHW patients (P<0.001). Hispanic patients had higher incidence of diabetes (41%; P<0.001) and hypertension (82%; P<0.001) compared with NHW and NHB patients but lower incidence of atrial fibrillation (30%; P<0.001) and hyperlipidemia (38%; P<0.001; Table 2).
|1||69 (83)||1 (1)||13 (16)||83|
|2||394 (85)||43 (9)||28 (6)||465|
|3||91 (57)||64 (40)||4 (3)||159|
|4||99 (26)||103 (27)||183 (48)||385|
|5||125 (79)||30 (19)||4 (3)||159|
|6||46 (46)||5 (5)||48 (48)||99|
|7||31 (89)||4 (11)||0 (0)||35|
|8||237 (84)||42 (15)||2 (1)||281|
|9||103 (77)||1 (1)||2 (2)||133|
|10||340 (96)||2 (1)||1 (1)||356|
|Variable||NHW (n=1535)||NHB (n=295)||Hispanic (n=285)||P value|
|Age, y, median (IQR)||71 (60–81)||63 (54–74)||60 (72–84)||<0.001*|
|Female||751 (48.9%)||136 (46.1%)||146 (51.2%)||0.463|
|Admission NIHSS, median (IQR)||16 (11–21)||16 (10–20)||16 (11–20)||0.638|
|ASPECTS, median (IQR)||9 (8–10)||9 (8–10)||10 (8–10)||0.061|
|Diabetes||385 (25.1%)||100 (33.9%)||117 (41.1%)||<0.001*|
|HTN||1114 (72.6%)||235 (79.7%)||233 (81.8%)||<0.001*|
|Afib||600 (39.1%)||63 (21.4%)||87 (30.5%)||<0.001*|
|HLD||685 (44.6%)||100 (33.9%)||109 (38.2%)||<0.001*|
|IV tPA||799 (52.1%)||122 (41.4%)||131 (46%)||<0.001*|
|Onset to groin, median (IQR)||249 (170–419)||235 (156–551)||233 (140–454)||0.487|
|ICA||330 (21.5%)||68 (23.1%)||46 (16.1%)|
|MCA, M1||758 (49.4%)||137 (46.4%)||169 (59.3%)|
|MCA, M2/M3||269 (17.5%)||55 (18.6%)||49 (17.2%)|
|ACA||9 (0.6%)||0||1 (0.4%)|
|Vertebral||17 (1.1%)||2 (0.7%)||3 (1.1%)|
|Basilar||132 (8.6%)||26 (8.8%)||13 (4.6%)|
|PCA||20 (1.3%)||7 (2.4%)||4 (1.4%)|
|Aspiration first||348 (22.6%)||62 (21%)||56 (19.6%)|
|Stent–retreiver first||630 (41%)||136 (46.1%)||137 (48.1%)|
|Solumbra first||345 (22.5%)||24 (8.1%)||23 (8.1%)|
|Other||212 (13.8%)||73 (24.7%)||69 (24.2%)|
|Attempts, median (IQR)||2 (1–3)||2 (1–3)||1 (1–3)||0.225|
|Procedure time, median (IQR, mins)||44 (27–72)||39 (25–59)||36 (23–60)||<0.001*|
|Symptomatic ICH||85 (5.5%)||23 (7.8%)||24 (8.4%)||0.089|
|90-d mRS, median (IQR)||3 (1–5)||4 (2–5)||4 (2–5)||0.011*|
|mRS<3 at 90-d||599 (39%)||104 (35.3%)||78 (27.4%)||<0.001*|
|90-d mortality||355 (23.1%)||45 (15.3%)||63 (22.1%)||0.011*|
Fewer NHB (41%) and Hispanic (46%) patients received intravenous tPA than NHW (52%) patients (P<0.001). NHW patients were more likely to undergo MT with Solumbra (23%) than NHB (8%) and Hispanic patients (8%), and Hispanic patients were more likely to undergo MT with stent retriever (48%) than NHW (41%) or NHB (46%) patients (P=0.001). Median procedure time was shorter in Hispanics (36 minutes) compared with NHB (39 minutes) and NHW (44 minutes) patients (P<0.001).
Favorable outcomes (modified Rankin Scale score 0–2) were reported at 90 days for 39% NHW, 35% NHB, and 27% Hispanic (P<0.001). Median 90-day modified Rankin Scale was 3 for NHW, 4 for NHB, and 4 for Hispanic (P=0.01). In multivariate modeling, age (odds ratio, 0.959 [95% CI, 0.948–0.970]), admission National Institutes Health Stroke Scale (0.916 [95% CI, 0.895–0.938]), onset to groin time (0.999 [95% CI, 0.999–1.000]), number of attempts (0.811 [95% CI, 0.710–0.925]), procedure time (0.994 [95% CI, 0.990–0.999]), and Hispanic status (0.502 [95% CI, 0.263–0.959]) were negatively correlated with favorable outcome (odds ratio E value, 2.173; CI E value, 1.254; Table 3).
|Variable||OR (95% CI)||P value|
|Age, y||0.959 (0.948–0.970)||0.000*|
|Admission NIHSS||0.916 (0.895–0.938)||0.000*|
|Onset to groin||0.999 (0.999–1.000)||0.012*|
|Procedure time||0.994 (0.990–0.999)||0.018*|
|IV tPA||0.979 (0.706–1.358)||0.901|
Our multicenter study provides important data on the impact of Hispanic status on outcomes following MT. In this study, Hispanic status was associated with unfavorable outcomes at 90 days despite younger median age and shorter procedure times. Hispanic patients additionally had higher median modified Rankin Scale scores at 90-day follow-up than did NHW patients.
We found worse functional outcomes in Hispanic patients compared to NHW despite similar admission National Institutes Health Stroke Scale, onset to groin time, shorter procedural time, and younger age. These findings from our international cohort likely represent the culmination of many biopsychosocial factors not captured by standard outcome metrics. However, Hispanic patients had higher rates of hypertension and diabetes which could contribute to worse outcomes. They also experienced a higher rate of symptomatic hemorrhage, despite fewer receiving intravenous tPA when compared to NHW patients. Ongoing analysis as more patients are added to the registry will be necessary to further delineate the significance of these trends.
Our study is the largest to date on the impact of these factors on outcome after MT, and the only prospectively collected database with 90-day follow-up. An earlier study showed neurological worsening following MT was more likely in minority groups but did not stratify for Hispanic patients specifically.4 Another found similar outcomes between NHW and NHB.5 One study of 810 patients admitted for stroke found NHB, but not Hispanic patients, were more likely to have a modified Rankin Scale score of >2 at discharge and were less likely to be discharged home.6 Minority patients undergoing inpatient rehabilitation for stroke have additionally been shown to have increased odds of difficulty with activities of daily living.7
Although reperfusion therapies play a pivotal role in outcomes following acute stroke, clinical outcomes are also heavily influenced by risk-factor modification and rehabilitation. Hispanics face significant obstacles to obtaining appropriate health care follow-up as a result of socioeconomic status and health insurance,8 and those variables are not captured in this analysis. The model E value suggests an unknown confounder would need to have an effect >2-fold on studied covariates and outcomes to explain away the association we describe. Thus, although unlikely, the potential for unmeasured confounding remains a limitation of the study. Recurrent vascular events were also not included in our analysis and could illuminate discrepancies in poststroke management. Further understanding discrepancies in long-term outcomes will require further studies.
Hispanic patients are less likely to have favorable outcome at 90 days following MT than NHW or NHB patients. Further study and reduction of discrepancies in post-treatment stroke care is warranted.
Stroke Thrombectomy and Aneurysm Registry
Sources of Funding
RECORD Guideline Checklist
STAR Collaborators: Daniel Raper, Patrick Brown, M. Reid Gooch, Nabeel Herial, Ajith Thomas, Justin Moore, Felipe Albuquerque, Louis Kim, Melanie Walker, Michael Chen, Stephan Munich, Daniel Hoit, Violiza Inoa-Acosta, Christopher Nickele, Lucas Elijovich, Fernanda Rodriguez-Erazú, Jan Liman, Michael Cawley, Gustavo Pradilla, Brian Howard, Brian Walcott, Zeguang Ren, Ryan Hebert, Joāo Reis, Jaime Pamplona, Rui Carvalho, Mariana Baptista, Ana Nunes, Russell Cerejo, Ashis Tayal, Parita Bhuva, Paul Hansen, Norman Ajibove, Alex Brehm, Jonathan Lena, Kimberly Kicielinski.
Disclosures Dr Starke’s research is supported by Neurosurgery Research and Education Foundation (NREF), Joe Niekro Foundation, Brain Aneurysm Foundation, Bee Foundation, and National Institutes of Health (NIH; R01NS111119-01A1) and (UL1TR002736, KL2TR002737), Miami Clinical and Translational Science Institute, National Center for Advancing Translational Sciences, National Institute on Minority Health and Health Disparities. Consulting agreements with Penumbra, Abbott, Medtronic, InNeuroCo, Cerenovus. Dr Spiotta reports consulting Cerenovus, Terumo, Siemens, Penumbra, Stryker and reports eesearch support from Penumbra, Medtronic, Stryker. Dr Yoo’s research is supported by Medtronic, Cerenovus, Penumbra, and Stryker; reports consulting with Penumbra, Cerenovus, and Vesalio; and reports equity in Insera Therapeutics. Dr Grossberg’s research is supported by Georgia Grant Alliance and also reports consulting with Cognition Medical. Dr Kan reports consulting with Stryker and Imperative Care. Dr Crowley reports consulting with Medtronic and Cerenovus. Dr Levitt’s research is supported by Medtronic, Styker, Philips; reports consulting with Medtronic, Minnetronix, Metis Innovative; and reports equity in Synchron, Cerebrotech, and eLoupes. Dr Mokin’s research is supported by NIH; reports consulting with Medtronic and Cerenovus; and reports equity in Serenity medical, Synchron, and Endostream. Dr Yavagal consulting for Medtronic, Cerenovus, Poseydon, Rapid Medical, Vascular Dynamics, NeuroSave. The other authors report no conflicts.
- 1. U.S. Census bureau quickfacts. 2019. https://www.census.gov/quickfacts/fact/table/US.Google Scholar
Cruz-Flores S, Rabinstein A, Biller J, Elkind MS, Griffith P, Gorelick PB, Howard G, Leira EC, Morgenstern LB, Ovbiagele B,; American Heart Association Stroke Council; Council on Cardiovascular Nursing; Council on Epidemiology and Prevention; Council on Quality of Care and Outcomes Research. Racial-ethnic disparities in stroke care: the American experience: a statement for healthcare professionals from the American Heart Association/American Stroke Association.Stroke. 2011; 42:2091–2116. doi: 10.1161/STR.0b013e3182213e24LinkGoogle Scholar
Rinaldo L, Rabinstein AA, Cloft H, Knudsen JM, Castilla LR, Brinjikji W. Racial and ethnic disparities in the utilization of thrombectomy for acute stroke.Stroke. 2019; 50:2428–2432. doi: 10.1161/STROKEAHA.118.024651LinkGoogle Scholar
Soomro J, Zhu L, Savitz SI, Sarraj A. Predictors of acute neurological worsening after endovascular thrombectomy.Interv Neurol. 2020; 8:172–179. doi: 10.1159/000499973CrossrefGoogle Scholar
Bouslama M, Rebello LC, Haussen DC, Grossberg JA, Anderson AM, Belagaje SR, Bianchi NA, Frankel MR, Nogueira RG. Endovascular therapy and ethnic disparities in stroke outcomes.Interv Neurol. 2018; 7:389–398. doi: 10.1159/000487607CrossrefGoogle Scholar
Jones EM, Okpala M, Zhang X, Parsha K, Keser Z, Kim CY, Wang A, Okpala N, Jagolino A, Savitz SI,. Racial disparities in post-stroke functional outcomes in young patients with ischemic stroke.J Stroke Cerebrovasc Dis. 2020; 29:104987. doi: 10.1016/j.jstrokecerebrovasdis.2020.104987CrossrefGoogle Scholar
Buie JNJ, Zhao Y, Burns S, Magwood G, Adams R, Sims-Robinson C, Lackland DT; WISSDOM Research Center Study Group. Racial disparities in stroke recovery persistence in the post-acute stroke recovery phase: evidence from the Health and Retirement Study.Ethn Dis. 2020; 30:339–348. doi: 10.18865/ed.30.2.339CrossrefGoogle Scholar
- 8. National Research Council. 2006. Hispanics and the Future of America. The National Academies Press. doi: 10.17226/11539CrossrefGoogle Scholar