Thrombolysis may benefit acute ischemic stroke patients with diabetes and prior stroke

Thrombolysis appeared to benefit patients with acute ischemic stroke who had concomitant diabetes or a history of stroke, according to a new study.

Guidelines in the U.S. and Europe have recommended that recombinant tissue plasminogen activator (rtPA) not be used in patients with diabetes or with prior stroke, although this is an area of some debate and these recommendations are not always followed in clinical practice. European researchers compared registry data to determine how diabetes and prior stroke affected outcomes of patients with acute ischemic stroke who received thrombolysis versus controls who did not. Ninety-day modified Rankin Scale scores, which measure function in seven categories on a scale of 0 to 6 (e.g., 0=asymptomatic, 5=bedbound and completely dependent, 6=dead) were compared after adjustment for age and National Institutes of Health Stroke Scale (NIHSS) score at baseline. The study results were published online Nov. 16 by Neurology and will appear in the Nov. 22 print issue.

Overall, data were available for 29,500 patients, 5,411 (18.5%) with diabetes, 5,019 (17.1%) with prior stroke and 1,141 (5.5%) with both. Adjusted modified Rankin Scale scores were better in treated patients than controls among those with diabetes, stroke, or both (odds ratios, 1.45, 1.55, and 1.23; P<0001 for all comparisons according to the Cochran-Mantel-Haenszel test). In the 19,939 patients without diabetes or prior stroke, the odds ratio for the adjusted modified Rankin Scale score was 1.53 (P<0.0001) for the comparison between treated patients and controls. Patient age (≤80 years or >80 years) did not affect outcomes.

The authors noted that reliable information was not available on symptomatic hemorrhage and acknowledged that the data used in their study were not randomized. However, they concluded that patients who received thrombolysis for acute ischemic stroke had better outcomes, even if they had diabetes or prior stroke, than those who did not receive the therapy. The researchers did not see a significant benefit in patients with both conditions but noted that the subgroup of these patients was small and that no interaction was observed between diabetes and prior stroke and treatment effect. Because the observed benefit of therapy in their study was similar to that seen in patients without diabetes and prior stroke, the authors concluded that there is no reason to withhold rtPA for acute ischemic stroke in patients with these conditions.

The author of an accompanying editorial reiterated the variety of opinions in this area, noting that clinicians have had many questions about how and whether recommendations about eligibility for thrombolysis should be followed. He called the current study “a concerted empirical effort” to determine whether such recommendations are valid for the significant number of patients—up to 15%—who present to the emergency department with a history of prior stroke and diabetes. “There appears to be no justification for the continued restriction of these patients from thrombolytic therapy,” the editorialist concluded.