Blood pressure reduction in hypertensive acute ischemic stroke patients does not affect cerebral blood flow

The effect of blood pressure (BP) reduction on cerebral blood flow (CBF) in acute ischemic stroke is unknown. We measured regional CBF with perfusion-weighted MRI before and after BP treatment in a three-armed non-randomized prospective controlled trial. Treatment arm assignment was based on acute mean arterial pressure (MAP). Patients with (MAP) >120 mmHg (n = 14) were treated with intravenous labetalol and sublingual (SL) nitroglycerin (labetalol group). Those with MAP 100-120 mmHg (n = 17) were treated with SL nitroglycerin (0.3 mg) ('NTG Group') and those with baseline MAP<100 mmHg (n = 18) were not treated with antihypertensive drugs (untreated group). Forty-nine patients (18 female, mean age 65.3 +/- 12.9 years) were serially imaged. Labetalol reduced MAP by 12.5 (5.7-17.7) mmHg, p = 0.0002. MAP remained stable in the NTG (6.0 (0.4-16, p = 0.3) mmHg and untreated groups (-0.3 (-2.3-7.0, p = 0.2) mmHg. The volume of total hypoperfused tissue (CBF<18 ml/100 g/min) did not increase after labetalol (-1.1 ((-6.5)-(-0.2)) ml, p = 0.1), NTG (0 ((-1.5)-4.5) ml, p = 0.72), or no treatment 0.25 ((-10.1)-4.5) ml, p = 0.87). Antihypertensive therapy, based on presenting BP, in acute stroke patients was not associated with an increased volume of total hypoperfused tissue.