This week has been published in the New England Journal of Medicine a very interesting article entitled «Aspirin in Patients Undergoing Noncardiac Surgery» and we’ll be talking about in the coming months . These are the results of the POISE -2 study ( Perioperative Ischemic Evaluation 2) conducted in more than 135 hospitals in 23 different countries on a total of 10,010 patients. This powerful study is going to clarify serious doubts about the usefulness of continued treatment with ASA in patients undergoing noncardiac surgery.

Until now we have made ​​a considerable effort to disseminate the need to maintain the treatment regimen with aspirin in the perioperative period for Noncardiac Surgery based primarily on observational studies , it appears that a clinical trial comes to drastically modify our clinical guidelines.

The POISE -2 study has several dimensions , in fact concerns us is only one of them , but there are more interventions in the same concerning the use of Clonidine . In what concerns to aspirin, 10,010 patients, all of them with cardiovascular risk factors according to their previous disease or the type of surgery were taken. These patients were randomized into two groups receiving a placebo or a daily regimen of 100 mg of aspirin after surgery, plus 200 mg prior to this , independently if they were taking aspirin or not . That is, patients taking aspirin were suspended treatment 3 days prior . This study excluded patients who had prescribed aspirin for Stent, because observational studies indicates greater risk of thrombosis if aspirin is removed during the first 6 weeks in conventional stents or during the first year in drug-eluting stents, it  is needed to remember that programmed non-Cardiac surgery has to be delayed in these patients until the suspension of dual therapy (clopidogrel + aspirin).

The objective of the study is to record the incidence of ischemic cardiovascular adverse effects that might result from risk factors , surgery or withdrawal of aspirin in patients previously taking it , primarily death and myocardial infarction , but background also others such as stroke, cardiac arrest , coronary revascularization , pulmonary embolism , deep vein thrombosis, atrial fibrillation, amputation, rehospitalization for cardiovascular reason and acute renal failure or dialysis. Massive bleeding , clinically significant hypotension and others like stroke, congestive heart failure , infection, and sepsis : Besides these effects of ischemic or thrombotic nature which may result from an increased risk of bleeding were recorded.

And now for the latest … what throws the study results ? Well, here comes the interesting part . It is demonstrated that patients receiving aspirin have a increased risk of bleeding with higher transfusion rate , and although it was already known it is assumed that it was offset by the decrease of thrombotic events and ischemic related to aspirin therapy and … it does not. The complication rate is very similar in both groups in terms of cardiovascular events, in fact no statistically significant differences. Where there is risk is in term of bleeding that is more abundant in the group taking aspirin, especially in terms of intraoperative bleeding . It is striking that aspirin treatment that has been proven effective in preventing the risk of myocardial infarction in nonsurgical patients is ineffective against surgery, for this, the authors have an explanation , the protective effect of aspirin against platelet aggregation is offset by the increased risk of bleeding in these patients, which is a cardiovascular risk factor per se.

In conclusion , administration of aspirin prior to noncardiac surgery and during the immediate postoperative period has no significant effect on mortality or myocardial infarction but significantly increases the risk of major bleeding . These findings are extrapolated both patients not previously taking aspirin and those who were treated with it.

Related Bibliography :

1. Devereaux PJ, Mrkobrada M , Sessler DI , Leslie K , Alonso- Coello P , Kurz A, et al. Aspirin in Patients Undergoing Noncardiac Surgery. N Engl J Med 2014 April 17 , 370 (16) :1494-503 .

2. Poldermans D , Bax JJ, Boersma E, De Hert S , Eeckhout E, Fowkes G, et al. Guidelines for pre -operative cardiac risk assessment and perioperative cardiac management in non – cardiac surgery : the Task Force for Preoperative Cardiac Risk Assessment and Perioperative Cardiac Management in Non – cardiac Surgery of the European Society of Cardiology (ESC ) and endorsed by the European Society of Anaesthesiology ( ESA). European journal of anaesthesiology . 2010. Pp. . 92-137 .

3. Fleisher LA, Beckman JA , Brown KA, Calkins H , Chaikof E, Fleischmann KE , et al. ACC / AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery : a report of the American College of Cardiology / American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 2002 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery ) : developed in collaboration With the American Society of Echocardiography , American Society of Nuclear Cardiology , Heart Rhythm Society, Society of Cardiovascular Anesthesiologists , Society for Cardiovascular Angiography and Interventions, Society for Vascular Medicine and Biology , and Society for Vascular Surgery. 2007. Pp. . E418 -99 .