Intensive vs Conventional Blood Pressure Lowering After Endovascular Thrombectomy in Acute Ischemic Stroke: The OPTIMAL-BP Randomized Clinical Trial
RCT (n=305) found post-procedure intensive BP management (systolic <140mmHg) led to a lower likelihood of functional independence (modified Rankin Scale score 0-2) at 3 months vs conventional BP control (systolic 140-180mmHg) (39.4% vs 54.4%, OR 0.56, 95%CI 0.33-0.96).
Source:
Journal of the American Medical Association
SPS commentary:
Authors state the results suggest intensive BP management should be avoided after successful endovascular thrombectomy in acute ischemic stroke.
A separate RCT (BEST-II, n=120) conducted to determine futility of lower systolic BP targets (<140 & <160 vs <180mmHg), investigating functional (modified Rankin score) & infarct volume, suggested a low probability of benefit from lower systolic BP targets if tested in a future larger trial.
A related editorial notes, because higher cerebral perfusion pressures may foster haemorrhagic transformation, it has been hypothesized that lowering systemic BP after successful reperfusion could decrease cerebral haemorrhagic complications. However, because cerebral autoregulation is impaired after ischemia, cerebral blood flow becomes pressure dependent and may decrease with lowering BP, leading to infarct expansion in areas that are still ischemic after incomplete procedural reperfusion. Hypotensive episodes and episodes of severe hypertension have been shown to worsen clinical outcomes. As a result, current international clinical guidelines recommend maintaining BP less than 185/105 mm Hg as well as avoiding decreases in the systolic BP (SBP) to less than 130 mm Hg.
The editorial notes the outcomes from these new studies, and 2 other previous RCTs which found no benefit for intensive BP control, but also that positive results were found in cohort analyses. However the fact that patients with lower BP achieved better outcomes in retrospective analyses, does not mean that lowering BP will improve outcomes following endovascular therapy. The association of low blood pressure after the procedure with better clinical outcomes may simply be driven by confounding due to better underlying physiology in these patients.
Editorial authors conclude that the best strategy after successful stroke management is to listen to what patients’ physiology reveals, let cerebral autoregulation be established, and intervene with BP control only for cases in whom severe hypertension is expected to increase the risk of intracerebral haemorrhage.