Hemodynamic Disturbances in Patients with Transient Ischemic Attack

Background: Poor hemodynamic function may impact management of neurological emergencies. Whether low cardiac index (CI) is a factor in transient ischemic attack (TIA) and acute ischemic stroke (AIS) is not well described. Objective: To compare CI measurements between ED patients with AIS versus TIA. Methods: We analyzed patients within an existing, prospective multicenter ED registry. Patient enrollment occurred at 4 academic EDs and was inclusive of patients with suspected stroke within 12 hours from symptom onset. We excluded patients that were pregnant or unable to provide consent. Study team member performed continuous non-invasive hemodynamic monitoring in the ED using arterial-wave form analysis. The final diagnosis was adjudicated by the treating stroke neurologist. Patients diagnosed with hemorrhage on CT or stroke mimics were excluded from analysis. Analysis consisted of univariate comparisons of hemodynamic parameters between patients diagnosed with TIA versus AIS. Results: There were 62 patients enrolled, 24 (39%) with TIA and 38 (61%) with AIS. Among patients with AIS, 15 (39%) had minor stroke (NIHSS 1 to 3) and 23 had moderate stroke (NIHSS 4 to 15). The average age of patients with TIA was 76 ± 24 compared to 60 ± 14 years in AIS patients (p \u3c 0.001). Patients with TIA and minor or moderate AIS did not differ in sBP (142 ± 27, 148 ± 26, and 132 ± 22 mmHg respectively, p=0.125) or systemic vascular resistance measurements (3658 ± 1213, 3100 ± 1271, and 3067 ± 1579 dynes/cm5/m2, p=0.28). Cardiac index was significantly lower among patients with TIA (2.3 ± 0.6 L/min/m2) compared to those with minor or moderate AIS (3 ± 0.9 L/min/m2), difference 0.7 L/min/m2 (95%CI 0.3-1.1 L/min/m2). Minor versus moderate AIS patients had no significant differences in hemodynamic parameters. Conclusions: On average, TIA patients in this cohort had significantly lower cardiac output than AIS patients. These findings raise the hypothesis that hemodynamic disturbances may be a common and underrecognized contributor to deficits in ED TIA patients