More information is needed on factors that may promote potentially harmful effects of these microbleeds, researchers say.
Patients in whom thrombolysis successfully leads to recanalization following acute ischemic stroke have worse outcomes if they experience cerebral microbleeds, according to research published online recently in Stroke.
Cerebral microbleeds “are generally considered markers of hemorrhagic and ischemic stroke and are predictors of hemorrhagic complications after a stroke,” write the authors, led by Kang-Ho Choi, MD, PhD (Chonnam National University Hwasun Hospital, Republic of Korea). While the impact of microbleeds on outcomes of symptomatic intracranial hemorrhage (ICH) have been evaluated, they say, their potential clinical impact in stroke patients treated with thrombolysis remains controversial.
Choi et al enrolled 1,532 patients who were treated with IV thrombolysis or mechanical thrombectomy in a prospective cohort study. On admission gradient echo (GRE) imaging, 10.8% of these patients had at least one microbleed, with 4.0% having one microbleed, 3.9% having two to four, and 2.9% having at least five (maximum 27).
There was no statistically significant association between the presence of microbleeds and favorable outcome at 3 months, defined as an mRS of 0-2, when considering all patients (44.3% vs 37.6%; P = 0.121). Among patients who achieved recanalization, however, the proportion with favorable outcomes was significantly higher in those without versus with microbleeds (57.0% vs 36.0%; P < 0.001).
Multivariate analysis of patients who achieved recanalization revealed that the presence of microbleeds—and in particular a high microbleed burden of at least five—as well as lobar location were significantly associated with less favorable 3-month outcomes and symptomatic ICH.
Outcomes After Microbleeds in Patients With Recanalization: Adjusted OR (95% CI)
|
|
Any |
≥ 5 |
Lobar |
|
mRS 0-2 |
0.57 (0.33-0.97) |
0.25 (0.09-0.62) |
0.45 (0.22-0.89) |
|
Symptomatic ICH |
3.21 (1.37-7.49) |
3.78 (1.10-12.91) |
2.98 (1.20-7.40) |
An analysis of subgroups revealed a statistically significant interaction between the presence of microbleeds and the ability of recanalization to predict functional outcome at 3 months (P = 0.006 for interaction).
“Our results suggest that it would be helpful to conduct a more detailed examination of the factors that may promote potentially harmful cerebral microbleed effects, such as sudden blood pressure elevations, hyperglycemia, or hyperthermia in patients treated with thrombolysis, and especially those with recanalization after mechanical thrombectomy,” Choi et al write.
However, they say, “our results do not imply that patients with [microbleeds] should not be treated . . . for recanalization, as patients with recanalization show a prognosis that is similar, and not worse, than those without recanalization.”
The investigators add that “it seems appropriate to consider [microbleed] status in individual risk stratification of poor clinical outcome following thrombolysis, including mechanical thrombectomy, and especially after recanalization for acute ischemic stroke.”
Source:
Choi KH, Kim JH, Kang KW, et al. Impact of microbleeds on outcome following recanalization in patients with acute ischemic stroke. Stroke. 2018;Epub ahead of print.
Disclosures:
Choi reports no relevant conflicts of interest.
