Adeola Olowu, MD

Maïer B, Fahed R, Khoury N, Guenego A, Labreuche J, Taylor G, et al. Association of Blood Pressure During Thrombectomy for Acute Ischemic Stroke With Functional Outcome: A Systematic Review. Stroke. 2019;50:2805–2812.

Greater than 50% of patients with successful recanalization are unable to regain functional independence at 3 months. There are several factors that contribute to the functional outcomes of patients who undergo mechanical thrombectomy; however, blood pressure is a prognostic factor that can be modulated (or managed).  This article addresses blood pressure management as a critical prognostic factor for outcome in acute ischemic stroke treated with mechanical thrombectomy. 

A systematic review of peri-procedural blood pressure values during mechanical thrombectomy was performed. A total of 9 studies out of 576 were eligible for systematic review after 2012. The 9 studies were comprised of 1 multicenter trial, 4 prospective trials, and 5 retrospective trials for a total of > 1000 patients. The systematic review revealed differences in how patient hemodynamics are being measured, as well as managed.

This article addresses several aspects of managing periprocedural blood pressure in this patient population. Such aspects are: patients with history of hypertension, BP management prior, during, and after mechanical thrombectomy, method of sedation during thrombectomy, how hemodynamic parameters are measured, medications for blood pressure management, and hemodynamic parameters effect on functional outcome.

  • Hemodynamic measurement was obtained mostly with both intraarterially and through BP cuffs in 5 out of the 9 studies, solely intraarterially in 1 out of 9 studies, only with BP cuffs in 2 studies, and BP monitoring method was not described in 1 study. 
  • Hemodynamic measurements were managed mostly in SBP, MAP, SBP and DBP, the number of minutes below BP parameters, and number of episodes below BP parameters. BP parameters were determined to be the same for patients who underwent mechanical thrombectomy with conscious sedation vs general anesthesia. 
  • BP parameters were mostly set equal to or above 140 mmHg (ex: >140, 140-160, 140-180 (before reperfusion)) with 1 parameter being set to MAP >70 mm Hg. 
  • Vasopressor use was evaluated in all 9 studies. Phenylephrine and Norepinephrine were the most used vasopressors in the study. 
  • 2 out of the 9 studies evaluated antihypertensives beta-blockers and calcium channel blockers for SBP > 185 mm Hg.
  • Vasopressors were used mostly in GA cases, while anti-hypertensives were used mostly in CS.  
  • Hemodynamic parameters demonstrating lowest SBP before recanalization, acute SBP drop, percentage of SBP drop, patients with SBP < 100, minimum DBP, SBP duration, greater than 40% drop in MAP vs baseline, lowest MAP prior to recanalization, and MAP decreases > 10% during thrombectomy were found to affect functional outcomes. 

This systematic review raised numerous questions for future studies, the most pertinent being “What is the best/effective method to assess hemodynamic function: intra-arterially or BP cuff?” and the need for uniform BP evaluation and management in research. BP evaluation post-procedurally was found in 1 of the 9 studies. Post-procedural BP parameters should potentially be evaluated in future studies regarding MT and BP for at least 24 hours. Future studies are needed for clear periprocedural BP parameters in the 4 phases the authors suggest: pre-intervention, pre-recanalization, post-recanalization, and post-intervention.