Comparison of Risk Factors, Treatment, and Outcome in Patients with Symptomatic Intracranial Atherosclerotic Disease in India and the United States

Background and Aims: Intracranial atherosclerotic disease (ICAD) is common in the Asian population, but less studied in South Asians compared to East Asians. We compared risk factors, treatments, and outcomes among consecutive patients with symptomatic ICAD from India with a mixed-ethnic cohort from Chicago, Illinois. Methods: Consecutive patients with symptomatic ICAD were enrolled at 2 academic medical centers in Kerala, India and Chicago, United States. Data on demographics, risk factors, initial stroke severity (National Institute of Health Stroke Scale score [NIHSS]), recurrent stroke, and 3-month functional outcome (modified Rankin Scale [mRS]) were prospectively collected. Recurrent stroke was defined as symptomatic recurrence of focal neurologic deficits associated with radiographic evidence of new cerebral infarction within 3 months of index admission. Results: 329 patients (117 from Kerala, 212 from Chicago) were included. Indian patients were younger (61 vs. 68, P < 0.001), less frequently had prior stroke history (15.4 vs. 32.5%, P = 0.001) and coronary artery disease (11.1 vs. 22.2%, P = 0.013) but had higher initial NIHSS score (median 6 vs. 3, P < 0.001). Both groups received reperfusion therapy in similar proportions (8.5 vs. 7.1%, P= 0.630) but at discharge, 90.6% of Indian patients compared to 59.0% of Chicago patients were treated with dual antiplatelet therapy. More recurrent strokes occurred in Chicago patients (21.7 vs. 1.9%, P < 0.001) but functional outcome did not differ significantly. Conclusion: Compared to patients in US with symptomatic ICAD, Indian patients were younger and had more severe strokes. However, Indian patients had lower rates of recurrent stroke, perhaps due to greater use of dual antiplatelet therapy.