Blood Pressure Variability Tied to Heart Surgery Mortality
Systolic blood pressure deviations outside the normal range predict 30-day mortality rates
FRIDAY, July 1 (HealthDay News) -- Variations in perioperative blood pressure are associated with 30-day mortality in cardiac surgical patients, with increased mortality risks for high-risk than low-risk patients, according to a study published in the July issue of Anesthesia & Analgesia.
Solomon Aronson, M.D., from the Duke University Medical Center in Durham, N.C., and colleagues investigated the association between SBP variability and 30-day mortality in 1,512 cardiac surgical patients participating in the Evaluation of CLevidipine In the Perioperative Treatment of Hypertension Assessing Safety Events trials who had perioperative hypertension. Blood pressure variability was measured as the product of magnitude and duration of SBP episodes outside defined ranges (area under the curve). The SBP ranges analyzed were 65 to 135 mm Hg intraoperatively, and 75 to 145 mm Hg pre- or postoperatively. The SBP ranges were progressively narrowed to 105 to 135 mm Hg intraoperatively, and 115 to 145 mm Hg pre- and postoperatively.
The investigators found a significant association between 30-day mortality and increased SBP variability outside a range of 75 to 135 mm Hg intraoperatively and 85 to 145 mm Hg pre- and postoperatively. For each incremental SBP deviation of 60 mm Hg x min/h, the odds ratio for 30-day mortality risk was 1.16. If the area under the curve increased from 0 to 300 mm Hg x min/h, the predicted probability of 30-day mortality increased from 0.2 to 0.5 percent and from 42.4 to 60.7 percent for low-risk and high-risk patients, respectively.
"Our data demonstrate an association between SBP variability as assessed by excursions outside perioperative SBP ranges and 30-day mortality," the authors write.
Several of the study authors disclosed financial ties with The Medicines Company, which funded the study.