NEW YORK (Reuters Health) – Discontinuation of aspirin within 5 days of combined coronary artery bypass graft (CABG) and valve surgery is associated with an increased risk of postoperative bleeding, compared with earlier discontinuation.

“Physicians should weigh the risk of bleeding vs. the benefit for aspirin use prior to CABG + valve surgery,” Dr. Leslie Cho from Cleveland Clinic, Cleveland, Ohio told Reuters Health in an email. “For example, if the patient has a drug-eluting stent and needs surgery, continuing aspirin makes sense. However, if the patient is at high risk of bleeding (such as redo, anemia, older, etc.), then holding aspirin makes sense.”

Dr. Cho and colleagues studied the effect of aspirin discontinuation earlier or later than 5 days before surgery on in-hospital mortality, myocardial infarction, stroke, and bleeding complications using data from the Cardiovascular Information Registry of Cleveland Clinic. Findings from 1963 patients on preoperative aspirin undergoing nonemergent CABG with valve surgery appear in the December 22nd online American Journal of Cardiology.

When patients were matched based on propensity scores, there was no difference between early and late discontinuation groups in the primary endpoint, a composite of in-hospital mortality, myocardial infarction, and stroke.

Significantly more patients in the late-use group (49%) than in the early-discontinuation group (42%) received postoperative transfusion (p=0.02), and there was a trend toward an increased reoperation for bleeding in the late-use group (6.1%) compared with the early-discontinuation group (3.7%) (p=0.08).

Current Society of Thoracic Surgeons guidelines recommend discontinuation of aspirin 3 to 5 days before elective CABG, whereas American College of Cardiology/American Heart Association guidelines suggest 7 to 10 days. Neither addresses patients needing CABG and valve surgery, the researchers note.

“For many years, surgeons and cardiologists had no real sense of when to stop aspirin,” Dr. Cho said. “I hope with (our) study, they can make a logical decision about when to stop aspirin.”

“We are currently planning to do a study looking at the level of aspirin function (arachidonic acid light transmittance aggregometry study) as relates to bleeding outcome to better define risk,” Dr. Cho added.

Effect of Timing of Chronic Preoperative Aspirin Discontinuation on Morbidity and Mortality in Patients Having Combined Coronary Artery Bypass Grafting and Valve Surgery

Am J Cardiol 22 December 2011.