Association of Intensive vs Standard Blood Pressure Control With Cerebral Blood Flow

Abstract

IMPORTANCEAntihypertensive treatments benefit cerebrovascular health and cognitive function in patients with hypertension, but it is uncertain whether an intensive blood pressure target leads to potentially harmful cerebral hypoperfusion.OBJECTIVE To investigate the association of intensive systolic blood pressure (SBP) control vs standard control with whole-brain cerebral blood flow (CBF). DESIGN, SETTING, AND PARTICIPANTSThis substudy of the Systolic Blood Pressure Intervention Trial (SPRINT) randomized clinical trial compared the efficacy of 2 different blood pressure-lowering strategies with longitudinal brain magnetic resonance imaging (MRI) including arterial spin labeled perfusion imaging to quantify CBF. A total of 1267 adults 50 years or older with hypertension and increased cardiovascular risk but free of diabetes or dementia were screened for the SPRINT substudy from 6 sites in the US. Randomization began in November 2010 with final follow-up MRI in July 2016. Analyses were performed from September 2020 through December 2021.INTERVENTIONS Study participants with baseline CBF measures were randomized to an intensive SBP target less than 120 mm Hg or standard SBP target less than 140 mm Hg. MAIN OUTCOMES AND MEASURESThe primary outcome was change in whole-brain CBF from baseline. Secondary outcomes were change in gray matter, white matter, and periventricular white matter CBF. RESULTS Among 547 participants with CBF measured at baseline, the mean (SD) age was 67.5 (8.1) years and 219 (40.0%) were women; 315 completed follow-up MRI at a median (IQR) of 4.0 (3.7-4.1) years after randomization. Mean whole-brain CBF increased from 38.90 to 40.36 (difference, 1.46 [95% CI,) mL/100 g/min in the intensive treatment group, with no mean increase in the standard treatment group (37.96 to 37.12; difference, -0.84 [95% CI, -2.30 to 0.61] mL/100 g/min; between-group difference, 2.30 [95% CI, 0.30-4.30; P = .02]). Gray, white, and periventricular white matter CBF showed similar changes. The association of intensive vs standard treatment with CBF was generally similar across subgroups defined by age, sex, race, chronic kidney disease, SBP, orthostatic hypotension, and frailty, with the exception of an indication of larger mean increases in CBF associated with intensive treatment among participants with a history of cardiovascular disease (interaction P = .05). CONCLUSIONS AND RELEVANCEIntensive vs standard antihypertensive treatment was associated with increased, rather than decreased, cerebral perfusion, most notably in participants with a history of cardiovascular disease.

Cerebral perfusion in untreated, controlled, and uncontrolled hypertension

“… 8 In contrast, another recent study involving participants aged 50 years or older (mean age 67.5 years) showed that intensive anti-hypertensive treatment (to achieve systolic blood pressure target of <120 mmHg) was associated with increased, rather than decreased, perfusion in the grey and white matter. 9 Our analysis suggests that anti-hypertensive treatment has no deleterious effect on cerebral perfusion if systemic arterial blood pressure is controlled on medication and supports the conclusions of the meta-analysis conducted by Van Rijssel and colleagues. 4 These findings highlight the importance of blood pressure control not only for the purpose of reducing the risk of stroke, cardiovascular disease, heart and renal failure, but also for the benefit of maintaining adequate cerebral blood flow and protecting the brain from harmful effects of chronically reduced perfusion.…”

“…In a recent longitudinal study undertaken in older (mean age 77 years) individuals with hypertension, the use of anti-hypertensive medication was found to be associated with lower grey matter CBF 8 . In contrast, another recent study involving participants aged 50 years or older (mean age 67.5 years) showed that intensive anti-hypertensive treatment (to achieve systolic blood pressure target of <120 mmHg) was associated with increased, rather than decreased, perfusion in the grey and white matter 9 . Our analysis suggests that anti-hypertensive treatment has no deleterious effect on cerebral perfusion if systemic arterial blood pressure is controlled on medication and supports the conclusions of the meta-analysis conducted by Van Rijssel and colleagues 4 .…”

Answering Clinical Questions Using Machine Learning: Should We Look at Diastolic Blood Pressure When Tailoring Blood Pressure Control?

“…In the currently published analysis of the SPS3 trial performed by Shihab et al [28], the authors found that even in patients with low baseline DBP and previous stroke, intensive SBP lowering did not increase the risk of stroke. The commented paper has been acknowledged in recent research showing adequate perfusion of the brain in MRI in patients with low DBP values [29]. Our findings support those of Shihab et al [28], as DBP in the chosen ML models did not improve stroke predictions.…”

Blood pressure control and risk of post-stroke dementia among the elderly: A population-based screening study

“…In addition, a meta-analysis suggested that there was no harmful effect of antihypertensive treatment on cerebral blood flow in older age ( 37 ). Secondary analysis of the SPRINT MIND randomized clinical trial study ( 38 ) showed that among 547 participants with cerebral blood flow measured at baseline, the average age was 67.5 ± 8.1 years. Compared with standard antihypertensive therapy, intensive antihypertensive therapy was related to increased not decreased cerebral perfusion, which was most obvious among participants with a history of cardiovascular disease.…”