Impact of revascularization therapies on outcome of posterior circulation ischemic stroke: The Indo-US stroke project

Abstract

Introduction: Posterior circulation strokes (PCS) have been less extensively studied than anterior circulation strokes (ACS), especially regarding revascularization therapies. We analyzed the differences in baseline stroke characteristics, revascularization therapy and 3-month outcomes between PCS and ACS in a large prospective multicentre Indian stroke registry.

Methods: Patients with acute ischemic stroke recruited in the Indo-US collaborative stroke project from January 2012 to August 2014 were classified into PCS and ACS based on imaging-confirmed infarct location. Demographics, stroke severity, risk factors, and mechanisms were compared. We further compared these parameters in the subgroups who received revascularization therapies (RT) and no revascularization therapies (NRT). The primary outcome was 3-month modified Rankin scale (mRS).

Results: Of 1889 patients (1270 males), 1478 (78.2%) had ACS and 411 (21.8%) PCS. The median NIHSS was lower in PCS (7 vs 11, p < 0.001). Diabetes mellitus and hypertension were more common in PCS and rheumatic heart disease in ACS. Small artery occlusion was higher in PCS (23.8% vs 12.9%, p < 0.001). Only 28 (6.8%) PCS received RT compared to 213 (14.4%) ACS. At 90 days, a good functional outcome (mRS 0-2) was more common in PCS (56.4% vs 45.9%, p < 0.001) in NRT group, while no significant difference was noted in RT group. Stroke territory was not an independent predictor of 3-month outcome in regression analysis. In-hospital mortality was not different between the groups.

Conclusions: The 3-month functional outcome and in-hospital mortality were not different between ACS and PCS. Compared to ACS, PCS received revascularization therapies less often.

Keywords: India; Outcome; Posterior circulation stroke; Stroke mechanism; Thrombolysis; Vertebrobasilar stroke.