Cardiac Stroke Volume Predicts Early Neurological Worsening in Acute Ischemic Stroke
Tirgari S, Miller J, Tsuei J, Lewandowski C, and Levy P. Cardiac stroke volume predicts early neurological worsening in acute ischemic stroke. Acad Emerg Med 2018; 25:S118.
Acad Emerg Med
Background: Early neurological worsening is common in acute ischemic stroke (AIS) and associated with increased morbidity. Patients with AIS also commonly have acute cardiac injury and hemodynamic disturbances. We tested the hypothesis that early, cardiac hemodynamic disturbances are associated with early neurological worsening in AIS. We secondarily tested if cardiac hemodynamics impact cerebral blood flow.
Methods: Prospective, observational study of AIS patients with a NIHSS > 3. Patients were enrolled in the ED as soon as AIS was suspected. Exclusion criteria were: time of onset > 12 hours and hemorrhagic stroke. We performed baseline non-invasive, continuous hemodynamic monitoring (Nexfin, Edwards Lifesciencs) and measured cerebral blood flow velocity with transcranial Doppler insonation of the middle cerebral arteries. We limited analysis to patients with confirmed stroke. Early neurological worsening was defined by any increase in the NIHSS over the first 24 hours. Analysis included logistic regression to test the effect of low cardiac stroke volume index and BP on neurological worsening, adjusting for age and baseline NIHSS.
Results: We enrolled 77 patients, 57 of whom had AIS confirmed on imaging. The mean age was 67 ± 13 years, 53% were female and 78% were African American. The median NIHSS was 6 (IQR 4,8) and baseline SBP was 151 ± 35 mmHg. Fifteen (26%) patients had neurological worsening. Blood pressure, age, and presenting NIHSS were not predictive of neurological worsening. Low stroke volume index was associated with neurological worsening (OR 5.2, 95% CI 1.5 - 18.3). There was no significant difference in baseline MCA mean flow velocity (MFV) between patients with or without neurological worsening (42 vs 41 cm/sec, p=0.8). There was a trend towards higher MFV in patients with normal stroke volume vs. those with low stroke volume (43 ± 14 vs 37 ± 9 cm/sec, p=0.07).
Conclusion: In this sample of low to moderate severity AIS patients, low stroke volume index was predictive of early neurological worsening, suggesting a hemodynamic effect on the ischemic penumbra.