Author + information
- Received March 7, 2013
- Revision received May 20, 2013
- Accepted June 11, 2013
- Published online September 17, 2013.
- Tobias Saam, MD∗∗ (, )
- Holger Hetterich, MD∗,
- Verena Hoffmann, PhD†,
- Chun Yuan, MD‡,
- Martin Dichgans, MD§,
- Holger Poppert, MD‖,
- Thomas Koeppel, MD¶,
- Ulrich Hoffmann, MD#,
- Maximilian F. Reiser, MD∗ and
- Fabian Bamberg, MD, MPH∗
- ∗Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- †Institute of Biomedical Epidemiology, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- ‡Department of Radiology, University of Washington, Seattle, Washington
- §Institute for Stroke and Dementia Research, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- ‖Department of Neurology, Technische Universität München, Munich, Germany
- ¶Division of Vascular and Endovascular Surgery, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- #Division of Vascular Medicine, Medical Clinic and Policlinic IV, Ludwig-Maximilians-University Hospital Munich, Munich, Germany
- ↵∗Reprint requests and correspondence:
Dr. Tobias Saam, Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital, Munich, Pettenkoferstrasse 8a, 80336 München, Germany.
Objectives This study sought to conduct a systematic review and meta-analysis to determine precise estimates of the predictive value of carotid intraplaque hemorrhage (IPH) as determined by magnetic resonance imaging (MRI) for cerebrovascular events.
Background There is emerging evidence that MR-based carotid atherosclerotic plaque assessment identifies high-risk features associated with cerebrovascular events. However, available data are based on smaller samples with heterogeneous source populations despite a promising value for noninvasive risk stratification.
Methods We searched PubMed, EMBASE, and the Cochrane Library through September 2012 for studies that followed >35 individuals after baseline MRI. Independent observers abstracted information on populations, MR techniques, outcomes, and study quality. Risk estimates of the presence of IPH for cerebrovascular events were derived in random effects regression analysis, and causes of heterogeneity were determined in meta-regression analysis.
Results We identified 8 eligible studies including 689 participants who underwent carotid MRI. The prevalence of IPH at baseline was high (49.0%). Over a median follow-up of 19.6 months, a total of 108 cerebrovascular events occurred (15.7% event rate). The presence of IPH was associated with an ∼6-fold higher risk for events (hazard ratio [HR]: 5.69; 95% confidence interval [CI]: 2.98 to 10.87). The annualized event rate in subjects with detectable IPH was 17.71% compared with 2.43% in patients without IPH. Meta-regression analysis showed symptomatic subjects had higher risks as compared with asymptomatic subjects (HR: 11.71, 95% CI: 5.17 to 26.48 vs. HR: 3.50, 95% CI: 2.59 to 4.73, p = 0.0065), Also, differences were observed for sex and sample size (all p < 0.01), with moderate visual publication bias due to missing smaller sample-size studies (p = 0.18).
Conclusions Presence of IPH on MRI strongly predicts cerebrovascular events. Homogenization of future studies is warranted to allow for sufficient assessment of level of evidence for intervention trials.
Dr. Saam is on the speakers' bureaus of MSD Merck, Sharp & Dohme and GlaxoSmithKline; and has received grant support from Diamed Medizintechnik. Dr. Yuan has been a consultant for ImagePace, Bristol-Myers Squibb Medical Imaging, and Boehringer Ingelheim; and has received research grants from Philips Medical and VP Diagnostics. Dr. Dichgans receives research support from BMB, NGFN-Plus, Wellcome Trust, and the Foundation for Vascular Dementia Research. Dr. Poppert has served on a scientific advisory board for Bayer Healthcare; received speaker honoraria from Bayer Healthcare, Boehringer Ingelheim, Novartis, and Roche; received funding for travel from Bayer Healthcare; and has also received research support from the government agencies Bundesministerium für Wirtschaft und Technologie, and Deutsche Stiftung Neurologie. Dr. Bamberg received speaker honoraria from Bayer Healthcare and Siemens Healthcare; and has received research grants from Bayer Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. The first two authors contributed equally to this work.
- Received March 7, 2013.
- Revision received May 20, 2013.
- Accepted June 11, 2013.
- 2013 American College of Cardiology Foundation