Nocturnal hypotension in patients after ischemic stroke: does it really matter?

We aimed to evaluate the presence of nocturnal hypotension (NHP) in ischemic stroke (IS) survivors using ambulatory blood pressure (BP) monitoring (ABPM).

We included fifty consecutive patients presenting at our outpatient clinic for review and who had been discharged for IS in the previous six months. 24-h ABPM was performed with Spacelab 90207 monitor. NHP episodes were considered those values on which the mean arterial pressure (MAP)<70mm Hg. Patients were divided into two groups according to the presence or absence of NHP.

We studied 31 men and 19 women, mean age 68±11years. Episodes of NHP were observed in 21 patients (42%). There were no significant differences with regard to clinical characteristics between groups. With regard to BP, patients with NHP had significantly lower mean 24-hour BPs, mean daytime BPs and mean nighttime BPs. Dipper pattern occurred more often in patients with NHP, although differences were only statistically significant in the diastolic BP values. Mean office readings were 142±26/77±13mm Hg (149±26 versus 133±20; P=0.06; 82±12 versus 71±12; P=0.008). None of the patients showed office SBP <90mmHg and only four had office DBP <60mmHg.

Episodes of NHP in patients with recent IS are common and difficult to detect with clinical cuff measurements. It is necessary to redefine the target BP levels in secondary stroke prevention, possibly because we are subjecting our patients to increased risk of NHP and cerebral hypoperfusion.