CLARIFY Findings Suggest Caution in Using BP-Lowering Treatments For CAD Patients
Findings from the CLARIFY Trial presented Aug. 30 during ESC Congress 2016 in Rome and simultaneously published in The Lancet suggest caution in the use of blood pressure (BP)-lowering treatment in patients with coronary artery disease.
Researchers analyzed data from 22,672 patients from 45 countries (excluding the U.S.) with stable coronary artery disease who were enrolled in the CLARIFY registry and treated for hypertension from November 2009 to June 2010. Systolic and diastolic BP before each event were averaged and categorized into 10 mm Hg increments. The primary outcome was the composite of cardiovascular death, myocardial infarction or stroke. Secondary outcomes were each component of the primary endpoint, all-cause death, and hospital admission for heart failure.
After a median follow-up of five years, increased systolic BP (SBP) of 140 mm Hg or more and diastolic BP (DBP) of 80 mm Hg or more were each associated with increased risk of cardiovascular events. SBP of less than 120 mm Hg was also associated with increased risk for the primary outcome, as well as increased risk for all secondary outcomes except stroke. Similarly, DBP of less than 70 mm Hg was associated with an increase in the primary outcome and in all secondary outcomes except stroke.
Study authors said their findings support the existence of a J-curve phenomenon. They also point out that the broad international cohort of patients who were treated in real-life conditions is a “particular strength” of the study and might have greater external validity than randomized trials. “There is a concern that low BP goals from randomized trials, when translated into routine practice, might be associated with higher adverse effects or worse outcomes, especially in older patients,” they said.
Meanwhile, the authors caution that results from the study “should not slow down the constant effort that is still needed to improve patient care, because even with the conventional pressure goal of less than 140/90 mm Hg, only about half of the population with hypertension is controlled.”
Deepak L. Bhatt, MD, MPH, FACC, echoes this sentiment in a commentary published Aug. 30 in the Journal of the American College of Cardiology (JACC). “A key cautionary note about appropriate BP targets is that the majority of patients with hypertension are not optimally treated, even using thresholds higher than those that are currently being debated,” he writes. “From a population health perspective, more would be gained from maintaining traditional BP targets for the entire population (perhaps adjusted for age) while sorting out the nuances of who might benefit from tighter BP control.”
He points out that another study by McEvoy et al., also published Aug. 30 in JACC, “shows that lower may not always be better with respect to BP control and, along with other accumulating evidence, strongly suggests careful thought before pushing BP control below current guideline targets, especially if the DBP falls below 60 mm Hg while the pulse pressure is >60 mm Hg.”
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