Introduction: Mechanical thrombectomy (MT) is now the standard of care for acute intracranial large vessel occlusion (LVO). There are currently no established guidelines for post MT blood pressure parameters in LVO patients. Our study examines the influence of blood pressure fluctuation and variation within the first 24 hours on clinical outcomes in post MT LVO patients.
Methods: A hospital based stroke registry retrospectively identified 111 consecutive patients undergoing MT for LVO (2012-2015). Blood pressure recordings within the 1st 24 hours post MT were analyzed: Maximum (Max), minimum, median and standard deviation (SD) of the systolic (SBP), diastolic (DBP) and mean arterial pressures (MAP) were calculated individually and as composite aggregates. Good outcomes were defined as National Institute of Health Stroke Scale (NIHSS) improvement of >=10 at discharge and or discharge NIHSS<=2 Poor outcomes were defined as post-MT intracerebral hemorrhagic (ICH) and mortality. Univariate (UV). and multivariate logistic regression (MV) were used to identify effect of blood pressure variation on good and poor outcomes. IBM-SPSS version 21 was used for data analysis.
Results: On UV analysis a lesser degree of 24 hour post MT SBP (median 16, IQR (Inter Quartile Range) 13, 23 mmHg, p=0.03) and DBP (Median 10, IQR 8, 12 mmHg p .04) SD were associated with good outcome. Maximum SBP was associated with higher rates of mortality (median 188, IQR 174-195 mmHg, p=0.03) and ICH (median 179, IQR 167-196 mmHg, p=0.05). There is no statistically significant association between Post MT 24 hours DBP or MAP maximum, minimum, median and SD values with associated poor outcomes. On MV, SBP variance and maximum SBP were found to be significantly associated with good outcomes (Odds Ratio (OR) 1.09, 95%CI (Confidence interval) 1 - 1.2, p=0.04) and mortality (OR 1.02, 95%CI 1 - 1.004, p=0.02) respectively.
Conclusion: Importance of proper blood pressure regulation within the 1st 24 hours of an LVO MT cannot be understated. To maintain good outcomes after MT, minimizing SBP SD becomes important. With the underlying premise of post cerebral ischemia induced vasomotor dysregulation, controlling Max SBP also decreases ICH and mortality. A prospective study is warranted to reinforce our findings.