Continued Antihypertensive Treatment Safe After Stroke

From Medscape Medical News
Continued Antihypertensive Treatment Safe After Stroke

Emma Hitt, PhD


July 23, 2010 — Continuing antihypertensive medication after a stroke does not appear to reduce 2-week death or dependency, cardiovascular event rate, or mortality at 6 months, according to new research.

Thompson G. Robinson, MD, published the findings of a randomized study — Continue Or Stop post-Stroke Antihypertensives Collaborative Study (COSSACS) — online July 12 in Lancet Neurology.

The study sought to assess the efficacy and safety of continuing or stopping preexisting antihypertensive drugs within 48 hours of when a patient had undergone nondysphagic, ischemic, or hemorrhagic stroke, and within 48 hours of the last dose of antihypertensive drugs.

"A spontaneous decrease in blood pressure usually occurs 4 to 10 days after stroke, but substantial reductions in blood pressure can be associated with cerebral hypoperfusion as a consequence of poststroke cerebral dysautoregulation," Dr. Robinson and colleagues note.

The prospective trial included patients from 49 participating UK National Institute for Health Research Stroke Research Network centers from January 1, 2003, to March 31, 2009.

Patients were randomly assigned to either continue (n = 379) or stop (n = 384) preexisting antihypertensive drugs for 2 weeks after their stroke. Of the patients who continued antihypertensive drugs, 72 of 379 reached the primary endpoint (death or dependency [modified Rankin scale score ≥ 3 points] at 2 weeks) compared with 82 of 384 patients in the stop group, which was not a significant difference between groups (P = .3).

The difference between the 2 groups in systolic blood pressure at 2 weeks was 13 mm Hg (95% confidence interval, 10 - 17 mm Hg), and the difference in diastolic blood pressure was 8 mm Hg (95% confidence interval, 6 - 10 mm Hg; P < .0001).

The incidences of serious adverse events, 6-month mortality, and major cardiovascular events were similar between groups.

"These neutral results might be because COSSACS was underpowered owing to early termination of the trial, and support the continuation of ongoing research trials," the investigators conclude.

According to the researchers, a post hoc analysis found that continuing antihypertensive drugs might be associated with reduced 2-week death and dependency in patients with ischemic stroke confirmed on neuroimaging. "However, this post-hoc subgroup analysis requires further evaluation in patient populations with well-defined stroke subtypes," they write.

A related editorial by Craig S. Anderson, MD, from the University of Sydney and Royal Prince Alfred Hospital, Australia, noted that the study was "underpowered...but still worthwhile," and the "safety data are useful in guiding clinical practice."

Dr. Anderson concluded that the findings add to an "emerging consistent message: oral antihypertensive treatment can be used safely in nearly all patients within the first few days of mildly disabling or non-disabling stroke or transient ischaemic attack because of the modest size (about 6–12 mm Hg systolic) and speed (several hours) of the blood-pressure reduction."

The authors have disclosed no relevant financial relationships.

Lancet Neurol. Published online July 12, 2010.