Average blood pressure values <130/80 mm Hg were associated with worse cardiovascular outcomes in patients with type 2 diabetes and recent acute coronary syndrome (ACS), a study found.
The researchers used data from the EXAMINE (Examination of Cardiovascular Outcomes with Alogliptin Versus Standard of Care) trial to investigate a target for clinician-measured blood pressure in patients with type 2 diabetes who are at high cardiovascular risk. The goal of the study was to evaluate the association between risk for major adverse cardiac events and cardiovascular death or heart failure in this population according to blood pressure values. Patients were followed in EXAMINE for up to 40 months, and blood pressure was assessed at one, three, six, nine, and 12 months after randomization during the first study year and every four months in subsequent years.
The researchers used a Cox proportional hazards analysis to determine risk for outcomes with each 10-mm Hg increase or decrease in blood pressure as measured by clinicians at follow-up visits. Ranges were ≤100 mm Hg to >160 mm Hg for systolic blood pressure and ≤60 mm Hg to >100 mm Hg for diastolic blood pressure. Reference ranges of 131 to 140 mm Hg and 81 to 90 mm Hg, respectively, were used for systolic and diastolic blood pressure, according to the 2015 American College of Cardiology/American Heart Association/American Society of Hypertension guidelines on hypertension treatment in patients with ischemic heart disease. The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, and nonfatal stroke. The study results were published Oct. 14 by the Journal of the American Heart Association.
The EXAMINE trial included 5,380 patients who had ACS 15 to 90 days before enrollment, 67.8% men, with a mean age of 61 years. They were followed for a median duration of 18 months. After adjustment for baseline covariates, patients with average clinician-measured follow-up systolic blood pressure values <130 mm Hg and those with baseline systolic blood pressure values <120 mm Hg or >160 mm Hg had a significantly increased risk for the primary outcome. A significantly increased risk was also seen in patients with average clinician-measured follow-up diastolic blood pressure values ranging from >70 mm Hg to 80 mm Hg and those with diastolic blood pressure values ranging from >60 mm Hg to 70 mm Hg at baseline. For all-cause mortality, hazard ratios were significantly greater for patients with average clinician-measured follow-up systolic blood pressure values ranging from >110 mm Hg to 120 mm Hg than in the reference group, as well as for patients with average clinician-measured follow-up diastolic blood pressure values ranging from >70 mm Hg to 80 mm Hg compared with the reference group. The authors noted a U-shaped relationship between cardiovascular outcomes and blood pressure.
Although 2017 guidelines from the American Heart Association and the American College of Cardiology recommend a target blood pressure of <130/80 mm Hg in patients with ischemic heart disease or type 2 diabetes, the results of the current study suggest that a slightly higher target may be better, the authors said. They also noted that they found a substantially higher cardiovascular risk in patients with clinician-measured blood pressure values of <120/70 mm Hg and that current guidelines have not comprehensively addressed this issue.
Limitations of the study include that blood pressure devices were not standardized across centers and that lower blood pressure levels achieved during the study were not necessarily due to purposefully intensified therapy. The authors concluded that their data suggest a harmful effect of very intensive control of blood pressure in patients with type 2 diabetes and ischemic heart disease and called for a randomized controlled trial to evaluate their findings.