MONTREAL – Patients who stayed on antiplatelet therapy close to – or even up until – major surgery fared just as well as those who stopped their medication earlier in a retrospective, single-center study.
The study found no difference in blood product administration, adverse perioperative events, or all-cause 30-day mortality regardless of whether patients stopped clopidogrel (Plavix) the recommended 5 days before surgery.
“We believe that continuing clopidogrel in elective and emergent surgical situations appears to be safe, and may challenge the current recommendations,” said presenter Dr. David Strosberg.
The study addressed a thorny question for surgeons, Dr. Strosberg said. “As surgeons, we face a dilemma: Do we take the risk of thrombotic complications in stopping the antiplatelet drugs, or do we take the risk of increased surgical bleeding with continuing therapy?”
The package insert for clopidogrel advises discontinuation 5 days prior to surgery. However, manufacturer labeling also states that discontinuation of clopidogrel can lead to adverse cardiac events, said Dr. Strosberg, a general surgery resident at Ohio State University in Columbus.
The aim of the study, presented at the annual meeting of the Central Surgical Association, was to ascertain whether continuing antiplatelet therapy increased the rate of adverse surgical outcomes in those undergoing major emergent or elective surgery.
Dr. Strosberg and his colleagues retrospectively reviewed the record of patients over a 4-year period at a single institution and included those undergoing major general, thoracic, or vascular surgery who were taking clopidogrel at the time of presentation.
Data collected included patient characteristics, including demographic data and comorbidities, as well as transfusion requirements and perioperative events.
A total of 200 patients who had 205 qualifying procedures and were taking clopidogrel were included in the study. Of these, 116 patients (Group A) had their clopidogrel held for at least 5 days preoperatively. The remaining 89 patients (Group B) had their clopidogrel held for less than 5 days, or not at all.
Patient demographics were similar between the two groups. Patients in Group A were more likely to have emergency surgery, to have peripheral stents placed, to have COPD or peripheral vascular disease, to have a malignancy, and to have received aspirin within five days of surgery (P less than .01 for all).
Blood product administration rates and volumes did not differ significantly between the two groups, and there was no difference between the groups in the incidence of myocardial infarctions, cerebrovascular events, or acute visceral or lower extremity ischemia.
Three patients in each group died within 30 days of the procedure, a nonsignificant difference. However, in the group that had clopidogrel held, three patients had perioperative myocardial infarctions, and two of these patients died. In discussing the study, Dr. Michael Dalsing said, “I think a lot of us would accept bleeding more over myocardial infarction.”
A subgroup analysis of the group who had clopidogrel held for fewer than 5 days compared outcomes for emergent vs. non-emergent surgery. The emergent surgery subgroup had a significantly higher rate of preoperative platelet transfusions, although numbers overall were small (2/17, 11.8%, vs. 0/72; P = .03).
Dr. Strosberg noted study limitations that included the retrospective, single-center nature of the study, and the fact that one variable, estimated blood loss, is notoriously subjective and inaccurate.
Dr. Dalsing, chief of vascular surgery at Indiana University, Indianapolis, said that he “was surprised that not even one patient went back for postoperative bleeding in this high-risk group of patients,” and raised the question of potential selection bias. Dr. Strosberg replied that comorbidities were ascertained by the physician at the time of surgery planning; since no differences were seen between study groups, investigators didn’t go back and parse out details about comorbid conditions.
In discussion following the presentation, surgeons spoke to the real-world challenges of performing surgery on a patient with antiplatelet therapy on board.
“Overall, I think your data support kind of a bias I have. Since I’m a vascular surgeon, we almost always operate on clopidogrel, and I don’t know if our bleeding risk is worse or better. But it’s something we almost have to do to keep our grafts going,” Dr. Dalsing said.
Dr. Peter Henke, professor of vascular surgery at the University of Michigan, Ann Arbor, said, “I’d be a little bit cautious with this. If you’ve ever done a big aortic procedure on someone on Plavix, I’ve seen them lose up to a couple of liters of blood just with oozing.”
“Those of us who do open aortic surgery know that very few things bleed like the back wall of an aortic anastomosis of a patient on Plavix,” echoed Dr. Peter Rossi, associate professor of vascular surgery at the Medical College of Wisconsin, Milwaukee.