Prevalence, Indications and Appropriateness of Antiplatelet Therapy in Patients Operated for Acute Aortic Dissection: Associations With Bleeding Complications and Mortality
What is the prevalence of antiplatelet therapy (AT) in patients who present with type A aortic dissection (AD) requiring surgery? Also, is AT prescribed appropriately, and does it affect clinical outcomes in these patients?
AT with aspirin (ASA), with or without an additional platelet inhibitor, is a cornerstone of treatment in acute coronary syndromes (ACS). The presentation of ACS can mimic the symptoms of acute AD, making initial treatment strategies complicated, particularly when AD is subsequently diagnosed and patients require emergent surgery. This was a single-center retrospective study of patients undergoing urgent surgery for acute (<14 days from symptom onset) type A AD from 2007-2011, at a regional hospital, with a catchment area of 1.4 million. Multiple presentation and perioperative variables were collected and analyzed.
A total of 133 patients were analyzed; 34% were women with a mean age of 60 ± 11 years. Median time from symptom onset to surgery was 7 hours. Of these 133 patients, 43 (32%) were on AT at the time of operation. Nineteen (14%) were on ASA alone, whereas 24 (18%) were treated with dual AT (DAT). Indications for AT in these 43 patients were only found to be clearly appropriate in 6 (14%) cases. The most common indication for AT was chest pain alone. AT was already being taken by 20% of these patients. DAT was only found to be clearly appropriate in 29% of cases. Compared with those who were not on AT, there was significantly more intraoperative bleeding (1800 ml vs. 800 ml, p = 0.03) and more postoperative bleeding (800 ml vs. 500 ml, p = 0.01) in the AT group. However, those treated with DAT did not have more bleeding than those treated with ASA alone. Longer cardiopulmonary bypass time and lower preoperative hemoglobin, along with lowest core temperature, predicted bleeding in excess of 1000 ml. Thirty-day mortality was significantly higher in the DAT group than in those with ASA alone or no AT.
This retrospective study suggests that patients undergoing surgery for acute AD are frequently prescribed AT preoperatively, with often less than appropriate indications. Patients on AT had more perioperative bleeding, and the use of DAT was associated with increased 30-day mortality.
The frequency of chest pain associated with ACS is far more common than AD; therefore, the diagnosis of AD is often overlooked in patients presenting with chest pain. AT is important in the treatment of ACS, but can be problematic in those who require urgent surgery, as this study demonstrates in patients with AD. Interestingly, the frequency of less appropriate AT was quite high. Overall, this study should serve to reinforce to physicians that AD needs to remain high on the differential in the presentation of chest pain. Additionally, use of AT and DAT should strictly be used in concrete cases of ACS, in order to avoid bleeding complications associated with these medications.
Clinical Topics: Acute Coronary Syndromes
Keywords: Prevalence, Postoperative Hemorrhage, Acute Coronary Syndrome, Hemoglobins, Platelet Aggregation Inhibitors, Chest Pain, Cardiopulmonary Bypass, Hemorrhage
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