The association between carotid intraplaque hemorrhage and outcomes of carotid stenting: a systematic review and meta-analysis

Background and purpose The purpose of this systematic review and meta-analysis was to determine whether carotid stenting patients with intraplaque hemorrhage (IPH) identified on preoperative MRI were more likely to suffer perioperative ischemic complications compared with patients without IPH. Methods We conducted a comprehensive literature search of studies published between January 1, 2005 and December 31, 2015 reporting perioperative outcomes of carotid stenting among patients with and without IPH on hemorrhage sensitive carotid MRI sequences. Clinical outcomes included perioperative (<= 30 days post-stenting) minor stroke, major stroke, death, and a composite outcome combining stroke, death, and myocardial infarction (MI). We also compared the rate of silent ischemia on diffusion weighted imaging (DWI) between groups. Statistical analysis was performed using a random effects meta-analysis. Results 9 studies with 491 unique patients (198 in the IPH group and 293 in the non-IPH group) were included. The rate of the composite outcome of any stroke, death, or MI within 30 days was 8.1% (13/160) in the IPH group and 2.1% (5/239) in the non-IPH group (OR=4.45, 95% CI 1.61 to 12.30, p<0.01). There were no significant differences between groups in the rates of minor stroke, major stroke, or death when considered individually. The rate of postoperative infarct on DWI was 49.7% (75/161) for the IPH group and 33.6% (81/241) for the non-IPH group (OR=2.01, 95% CI 1.31 to 3.09, p<0.01). Conclusions Our systematic review and meta-analysis demonstrated that patients with IPH on pre-carotid stenting MRI had higher rates of silent ischemia as well as of a composite outcome of perioperative stroke, death, and MI compared with those without IPH.