Blood Pressure Management after Mechanical Thrombectomy

Periprocedural factors influencing functional outcomes after mechanical thrombectomy (MT) for large vessel occlusion strokes (LVOS) are increasingly recognised. Besides multiple studies on ship strategies and anaesthesia, the management of blood pressure (BP) and blood pressure targets during and after MT has extensively been studied.

BP targets prior to MT are based on current guideline recommendations taking into account data on intravenous thrombolysis. Penumbra and collateral artery perfusion are the basis for higher systolic BP (SBP) targets prior to MT and during IVT (150-180 mmHg) (1) (2). Expert opinions suggest no use of antihypertensives prior successful recanalization up to SBPs of >200 mmHg, while in bridging thrombolysis scenarios the upper SBP limit should be around 180 mmHg to avoid intracerebral hemorrhage (ICH) (3).

Optimal management of BP after successful reperfusion is less clear. Retrospective studies indicated different BP trajectories after MT with higher and lower mean BPs associated with higher mortality rates and unfavorable outcomes (4) (5). In these studies, LVO patients with high or high to moderate BP trajectories (mean BPs >140 mmHg) had significantly higher odds of unfavorable functional outcomes and increased risk of symptomatic ICH (6). One study identified increased SBP 24h after MT to be a predictor of early neurological deterioration, poorer 90 day modified Rankin Scale scores and higher rates of symptomatic ICH (7). In addition, BP variability and the amount of BP peaks have been identified as independent predictors for unfavorable functional outcomes (7) (8).

After publication of this data, the question remained if elevated BP after MT is an epiphenomenon or causative linked to unfavorable outcome. It has been speculated, that increased BPs contribute to capillary leak, reperfusion injury and higher odds of symptomatic ICH and hemorrhagic transformation due to impaired cerebrovascular autoregulation in the ischemic vessels. To clarify the causative link, one large, retrospective analysis including data from 10 comprehensive stroke centers found that BP reduction after successful MT within the first 24 hours was inversely correlated with functional outcomes, providing evidence for a therapeutical target (9). In the same population SBP goals of <140 mmHg after MT were associated with favorable functional outcomes, as well as lower odds of decompressive hemicraniectomy and symptomatic ICH compared to a SBP goal of <180 mmHg (10). Concerning RCTs, one study including 324 patients in four MT centers, found no significantly different rates of ICH or mortality 16-24h after MT in two treatment groups with BP goals of 100-130 mmHg and 130-180 mmHg.(11) Another open-label, blinded-endpoint, randomized controlled trial at 44 tertiary-level hospitals in China including 802 patients after MT assigned patients in an intensive BP lowering- and less intensive BP lowering group. BP targets for the intensive group were <120 mmHg and less intensive group 140-180 mmHg, to be achieved within 1 hour and sustained 72 h after MT. This study was stopped due to persistent efficacy and safety concerns, as patients in the intensive BP lowering group were less likely to have favorable functional outcomes and had higher rates of early neurological deterioration and mortality (12). Multiple studies are on the way to further provide more robust evidence for BP targets after MT. The Blood pressure After Endovascular Stroke Therapy (BEST-II, NCT04116112), Outcome in patients Treated with Intraarterial Thrombectomy- Optimal Blood Pressure Control (OPTIMAL_BP; NCT04205305), Invasive Control of Blood Pressure in Acute Ischemic Stroke After Endovascular Therapy on Clinical Outcomes (CRISIS I; NCT04775147) trials will compare various outcome parameters using SBP cut-off values of 140 mmHg (13). Based on current evidence, it seems reasonable to aim for higher SBPs (140-180 mmHg) prior to MT and in patients with unsuccessful reperfusion (TICI 0 to 2a). This especially seems to be relevant in cases with concomitant extracranial stenosis, poor collateral status and intracranial arteriosclerotic disease (ICAD). After successful recanalisation (TICI 2b, 2c or 3), systolic BP targets of 120-140 mmHg seem to have beneficial effects (10) (14), while intensive BP lowering to SBPs <120 mmHg seems to have adverse effects on functional outcome and mortality rates (maybe particularly in Asian populations). Ongoing trials will help to further specify BP targets depending on the degree of recanalisation after MT, to optimise individualised treatment decisions.

References:

1. Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the AHA/ASA. Stroke . 50:e344., 2019.
2. Goyal M, Demchuk AM, Menon BK, et al. Randomized assessment of rapid endovascular treatment of ischemic stroke. . N Engl J Med . 372:1019., 2015.
3. Biller J, Bulwa Z, Gomez CR, Morales-Vidal S. Stroke snapshot: Blood pressure management after acute ischemic stroke. . Pract Neurol (Fort Washington, Pa.) . March/April:13., 2019.
4. Prasad A, Kobsa J, Kodali S, et al. Temporal profiles of systolic blood pressure variability and neurologic outcomes after endovascular thrombectomy. . Eur Stroke J. . 7(4):365-375. , 2022 D.
5. Petersen NH, Kodali S, Meng C, et al. Blood Pressure Trajectory Groups and Outcome After Endovascular Thrombectomy: A Multicenter Study. . Stroke. . 53(4):1216-1225. , 2022 .
6. Anadani M, Orabi MY, Alawieh A, et al. Blood Pressure and Outcome After Mechanical Thrombectomy With Successful Revascularization. . Stroke. . 50(9):2448-2454., 2019 .
7. Katsanos AH, Malhotra K, Ahmed N, et al. Blood Pressure After Endovascular Thrombectomy and Outcomes in Patients With Acute Ischemic Stroke: An Individual Patient Data Meta-analysis. Neurology. . 98(3):e291-e301., 2022 .
8. Maier IL, Tsogkas I, Behme D, et al. High Systolic Blood Pressure after Successful Endovascular Treatment Affects Early Functional Outcome in Acute Ischemic Stroke. . Cerebrovasc Dis. . 24;45(1-2):18-25. , 2017 .