CATIS Trial on Blood Pressure Reduction

Dallas—Previous clinical trials have found that lowering blood pressure (BP) reduces the risk of stroke in hypertensive and normotensive patients with a history of stroke or transient ischemic attack. However, the effect of antihypertensive treatment in patients with acute ischemic stroke and elevated BP is still uncertain.

A recent study looked to evaluate whether immediate (within 48 hours) PB reduction in patients with acute ischemic stroke would reduce death and major disability at 14 days or hospital discharge. The results of this trial were presented at the AHA Scientific Sessions during a session titled Blood Pressure Reduction Among Acute Stroke Patients A Randomized Controlled Clinical Trial. These results were also recently published in Journal of the American Medical Association [JAMA. DOI:10.1001;jama.2013.282543].

The CATIS (China Antihypertensive Trial in Acute Ischemic Stroke) trial was a multicenter, randomized, controlled trial that included 4071 patients who were randomly assigned to receive either antihypertensive treatment (n=2038) or discontinue all antihypertensive medications during hospitalization (n=2033). The study was conducted in 26 hospitals across China. Patients were eligible for the study if they were ≥22 years of age, had ischemic stroke confirmed by computed tomography or magnetic resonance imaging of the brain within 48 hours of symptom onset, and had elevated systolic BP between 140 mm Hg and <220 mm Hg. Patients with severe heart failure, acute myocardial infarction or unstable angina, atrial fibrillation, aortic dissection, cerebrovascular stenosis or resistant hypertension, and patients in a deep coma were excluded.

The study aimed to evaluate whether an antihypertensive treatment intervention aimed at lowering systolic BP by 10% to 25% within the first 24 hours after randomization, achieving a systolic BP <140 mm Hg and diastolic BP <90 mm Hg within 7 days, and maintaining this level of BP control during the remainder of the patient’s hospitalization would reduce adverse clinical outcomes when compared with patients in the control group not receiving antihypertensive treatment.

In the intervention group, several antihypertensive agents were used, including intravenous angiotensin-converting enzyme inhibitors (first line), calcium channel blockers (second line), and diuretics (third line). These were used individually or in combination depending on the patient.

The primary end point was a combination of death within 14 days after randomization and major disability at 14 days or at hospital discharge. Secondary end points included all-cause mortality and major disability at the 3-month post-treatment follow-up.

In the treatment group, mean systolic BP was reduced from 166.7 mm Hg to 144.7 mm Hg (−12.7%) within 24 hours. In the control group, mean systolic BP was reduced from 165.6 mm Hg to 152.9 mm Hg (−7.2%; difference, −5.5%; 95% confidence interval [CI], −4.9%-−6.1%; absolute difference, −9.1 mm Hg; 95% CI, -10.2-−8.1%; P<.001).

At day 7 after randomization, mean systolic BP was 137.3 mm Hg in the treatment group and 146.5 mm Hg in the control group (difference, −9.3 mm Hg; 95% CI, −10.1-−8.4; P<.001).

The number of deaths or major disability did not differ between groups—683 events in the treatment group and 681 in the control group (odds ratio [OR], 1; 95% CI, 0.88-1.14; P=.98). The secondary end points of death and major disability at 3 months also did not differ—500 in the treatment group and 502 in the control group (OR, .99; 95% CI, 0.86-1.15; P=.93).

Overall, the CATIS trial results found that for patients with acute ischemic stroke, BP reduction with antihypertensive medications did not reduce the likelihood of death and major disability, compared with the control group.