Journal article
Do Patient Characteristics Explain the Differences in Outcome Between Medically Treated Patients in SAMMPRIS and WASID?
Stroke (1970), Vol.46(9), pp.2562-2567
09/2015
DOI: 10.1161/STROKEAHA.115.009656
PMCID: PMC4550543
PMID: 26251251
Abstract
The Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) medical group had a much lower primary end point rate than predicted from the preceding Warfarin Aspirin Symptomatic Intracranial Disease (WASID) trial. This result has been attributed to the aggressive medical therapy used in SAMMPRIS, but an alternative hypothesis is that SAMMPRIS patients were at lower risk. We undertook analyses to evaluate these competing hypotheses.
Using proportional hazards regression, we compared the SAMMPRIS primary end point between SAMMPRIS medical patients and WASID patients meeting the same qualifying criteria adjusted for confounding baseline characteristics.
The unadjusted comparison of the SAMMPRIS primary end point showed a significantly higher risk for WASID patients (P=0.009, logrank test) with 12 month Kaplan-Meier estimates of 21.9% in WASID and 12.6% in SAMMPRIS and hazard ratio 1.9 (95% confidence interval =1.2-3.0). The analyses identified the following confounding factors that varied between the studies and that conferred a higher risk: lack of statin use at enrollment (hazard ratio =1.8, 95% confidence interval =1.1-2.9, P=0.027) that was more prevalent among WASID patients (39% versus 14%, P<0.0001) and prior infarcts in the territory of the symptomatic vessel (hazard ratio =1.8, 95% confidence interval =1.1-2.9, P=0.023) that was more prevalent among SAMMPRIS patients (34% versus 22%, P=0.015).The hazard ratio for WASID versus SAMMPRIS adjusted for these 2 characteristics was 1.9 (95% confidence interval =1.1-3.2).
After adjustment for confounding baseline characteristics, WASID patients had an almost 2-fold higher risk of the SAMMPRIS primary end point, which supports the hypothesis that the lower rate of the primary end point in the medical arm of SAMMPRIS compared with WASID patients was as a result of the aggressive medical management used in SAMMPRIS.
URL: http://www.clinicaltrials.gov. Unique identifier: NCT00576693.
Details
- Title: Subtitle
- Do Patient Characteristics Explain the Differences in Outcome Between Medically Treated Patients in SAMMPRIS and WASID?
- Creators
- Seemant Chaturvedi - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.). SChaturvedi@med.miami.eduTanya N Turan - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)Michael J Lynn - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)Colin P Derdeyn - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)David Fiorella - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)L Scott Janis - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)Marc I Chimowitz - From the Department of Neurology, University of Miami, Miami, FL (S.C.); Department of Neurosciences, Medical University of South Carolina, Charleston, SC (T.N.T., M.I.C.); Department of Biostatistics and Bioinformatics, Emory University Rollins School of Public Health, Atlanta, GA (M.J.L.); Mallinckrodt Institute of Radiology and the Departments of Neurology and Neurosurgery, Washington University School of Medicine, St Louis MO (C.P.D.); Department of Neurosurgery, State University of New York, Stony Brook, NY (D.F.); and National Institute of Neurological Disorders and Stroke, National Institute of Health, Bethesda, MD (L.S.J.)
- Resource Type
- Journal article
- Publication Details
- Stroke (1970), Vol.46(9), pp.2562-2567
- DOI
- 10.1161/STROKEAHA.115.009656
- PMID
- 26251251
- PMCID
- PMC4550543
- NLM abbreviation
- Stroke
- ISSN
- 0039-2499
- eISSN
- 1524-4628
- Publisher
- United States
- Grant note
- R01 NS051688 / NINDS NIH HHS UL1 RR024131 / NCRR NIH HHS U01 NS058728 / NINDS NIH HHS UL1RR029890 / NCRR NIH HHS UL1 RR029890 / NCRR NIH HHS UL1RR029889 / NCRR NIH HHS TL1 RR029889 / NCRR NIH HHS U10 EY013287 / NEI NIH HHS R01 NS036643 / NINDS NIH HHS P30 EY006360 / NEI NIH HHS K24 NS050307 / NINDS NIH HHS UL1 TR001427 / NCATS NIH HHS R01 NS051631 / NINDS NIH HHS UL1RR029882 / NCRR NIH HHS K23 NS069668 / NINDS NIH HHS UL1RR024131 / NCRR NIH HHS UL1 RR029882 / NCRR NIH HHS UG1 EY013287 / NEI NIH HHS
- Language
- English
- Date published
- 09/2015
- Academic Unit
- Neurology; Radiology; Iowa Neuroscience Institute; Neurosurgery
- Record Identifier
- 9984020758402771
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