Pulse Pressure Predicts Risk of Stroke After Cardiac Surgery

Preoperative brachial pulse pressure (PP), an index of vascular stiffness, is a strong predictor of stroke following cardiac surgery, and it is independent of chronological age, according to a new study.

Researchers at Johns Hopkins Hospital (Baltimore, MD, USA) conducted a retrospective review and as assessed stroke risk factors by measuring brachial PP measurements in 703 patients (63.4% men and 36.6% women) who underwent cardiac surgery and were followed for a mean of 348 days. During that time, 42 patients experienced a stroke.

The study found that patients who suffered a stroke had a significantly higher average pulse pressure (81.2 mm Hg) compared with patients who did not have strokes (64.5 mm Hg). The unadjusted hazard ratio for stroke was 1.32 for every 10 mm Hg increase in pulse pressure; this relationship remained highly significant in the adjusted model, which included age. Stroke-free survival was significantly higher if pulse pressure was less than 72 mm Hg. The researchers commented that hypoperfusion appeared to increase risk of stroke in cardiac surgery, and that it may be beneficial if the blood pressure is kept somewhat high while the patient is on the heart-lung bypass machine. The study was published in the October 2007 issue of Hypertension.

"Diet, lifestyle modification and blood pressure medications mitigate stroke risk in the long-term,” said co-investigator Dr. Dan E. Berkowitz. "In the short term, for the cardiac surgery patient, it's important to maintain blood flow to the brain.”


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