Observational study outlines BP guidelines for hypertensive patients with stroke

Blood pressure (BP) of less than 130/80 mm Hg has been associated with improved outcomes in hypertensive patients who previously suffered a stroke, according to new research published in the Journal of the American Heart Association.

BP and hypertension management have made headlines lately due to the American Heart Association’s updated set of guidelines, which were released in mid-November. For the first time in 14 years, the AHA lowered its threshold for hypertension from 140/90 mm Hg to 130/80 mm Hg, redefining what it means to live with high blood pressure. The recent SPRINT (Systolic Blood Pressure Intervention) trial also found a systolic blood pressure (SBP) goal of less than 120 mm Hg was superior to a goal of less than 140 mm Hg in reducing cardiovascular risks.

Though all this information has contributed greatly to researchers’ pool of knowledge about hypertension, the SPRINT study excluded hypertensive subjects with previous stroke, since the SPS3 (Secondary Prevention of Small Subcortical Strokes) trial previously proved the benefits of strict SBP lowering in patients with previous lacunar infarction, first author Chan Joo Lee, MD, PhD, and colleagues said in the JAHA study.

As a result, Lee and co-authors wrote, patients with both high blood pressure and previous stroke are left in limbo.

“Whether strict SBP lowering is beneficial for all hypertension subjects with previous stroke is unclear,” they wrote. “However, it is difficult to verify this through large-scale clinical studies, so using observational cohort data may be helpful.”

The team used the Korea National Health Insurance Service (NHIS) cohort to identify nearly 3,000 patients who’d been diagnosed with both stroke and hypertension between January 2003 and December 2006, according to the study. The study population was split into three groups based on mean systolic and diastolic blood pressure, and the authors compared BP data with all-cause and cardiovascular mortality during an 11-year follow-up period.

Next to patients with an SBP of greater than 140 mm Hg, those with an SBP of 130 to 140 mm Hg saw significantly lower risk of all-cause death, cardiovascular mortality and fatal ischemic stroke. An even lower SBP—less than 130 mm Hg—was associated with a further lower risk of nonfatal hemorrhagic stroke.

Patients who recorded diastolic blood pressures of between 80 and 90 mm Hg saw significant reductions in risk of all-cause mortality, according to the data, as well as cardiovascular death. Even lower numbers were linked to more dramatically reduced risk of nonfatal hemorrhagic stroke, all-cause death and cardiovascular mortality.

Lee et al. said the numbers require further validation by future studies.

“Because this study is based on an observational cohort, the results from this study are only hypothesis-generating,” they wrote. “Nevertheless, the results support the necessity for future studies to demonstrate the benefit of strict BP control in all patients with stroke.”