The impact of intracranial carotid artery calcification on the development of thrombolysis-induced intracerebral hemorrhage

Background: We aimed to assess whether intracranial carotid artery calcification (ICAC) evident on head computed tomography is a risk factor for symptomatic intracerebral hemorrhage (sICH) following tissue plasminogen activator (tPA) treatment for acute stroke. Methods: We classified 297 consecutive patients into 2 groups (no to mild ICAC and moderate to severe ICAC) according to ICAC severity. Outcome measures included detection of intracerebral hemorrhage and assessment using a modified Rankin scale (mRS) at 1 month and 1 year after stroke. Results: ICH (any type) was significantly more common in patients with moderate to severe ICAC than in patients with no to mild ICAC (22.5% versus 12%; relative risk [RR], 1.67; 95% confidence interval [CI], 1.1-2.5; P <.05). The moderate to severe ICAC group tended to have a higher percentage of sICH, but this association was not statistically significant (RR, 1.57; 95% CI,.75-3.3, P >.05). Multivariate adjusted regression analysis revealed that moderate to severe ICAC was an independent risk factor for ICH following tPA treatment (odds ratio, 2.52; 95% CI, 1.07-5.94; P =.04). Dependent functional outcome (mRS score 3-6) at 1-month and 1-year follow-up was significantly associated with moderate to severe ICAC (RR, 1.56; 95% CI, 1.06-2.27; and RR, 1.56; 95% CI, 1.06-2.33; P <.05). However, ICAC was not an independent factor of functional dependency at 1-month and 1-year follow-up in the final multivariate regression model. Conclusion: A significantly higher percentage of patients with moderate to severe ICAC developed ICH following tPA administration for stroke. ICAC severity is an independent risk factor for ICH events. ICAC severity can help predict short-term and long-term functional dependency in tPA-treated patients, although this can be confounded by other cardiovascular risk factors and stroke severity.