The Effects of Intensive Antihypertensive Treatment Targets on Cerebral Blood Flow and Orthostatic Hypotension in Frail Older Adults

Background Guidelines recommend restrictive antihypertensive treatment (AHT) in hypertensive frail older adults, as intensive AHT is assumed to cause cerebral hypoperfusion and orthostatic hypotension (OH). However, studies directly examining these assumptions in older, frail individuals are lacking. Methods Fourteen frail hypertensive patients (six females; age 80.3±5.2 years; Clinical Frailty Scale 4-7; unattended SBP ≥150 mmHg) underwent measurements before and after a median of 7-weeks AHT (SBP target ≤140 mmHg). Transcranial Doppler measurements of middle cerebral artery velocity (MCAv), reflecting changes in cerebral blood flow (CBF), were combined with finger plethysmography recording of continuous BP. Transfer function analysis assessed cerebral autoregulation (CA). ANCOVA analyzed AHT-induced changes in CBF and CA, and evaluated non-inferiority of the relative change in CBF (margin: -10%; covariates: pre-AHT values and AHT-induced relative mean BP change). McNemar-tests analyzed whether the prevalence of (initial) OH, assessed by sit/supine-to-stand challenges, increased with AHT. Results Unattended mean arterial pressure decreased by 15 mmHg following AHT. Ten (71%) participants had good quality TCD assessments. Non-inferiority was confirmed for the relative change in MCAv (95%CI -2.7, 30.4). CA was normal and remained unchanged following AHT ( P >0.05). None of the 14 participants had an increase in the prevalence of OH or initial OH ( P ≥0.655). Conclusions We found that AHT in frail, older patients does not reduce CBF, is not associated with impaired CA, and does not increase (initial) OH prevalence. These observations may open doors for more intensive AHT targets upon individualized evaluation and monitoring of hypertensive frail patients. Clinical Trial Registration ClinicalTrials.gov ( NCT05529147 ) and EudraCT (2022-001283-10).