ABC | Volume 111, Nº4, Octuber 2018

Original Article Borges et al Inadequate management of antiplatelet agents Arq Bras Cardiol. 2018; 111(4):596-604 patients, 10 when they need a non-cardiac surgery, surgeons and anesthesiologists frequently have to face the decision of whether to interrupt or not antiplatelet therapy in those patients during the perioperative period considering the risks of the occurrence of thrombi or bleedings, respectively. 11-13 Thus, in order to help physicians make decisions in the perioperative period referring to antiplatelet therapy, the recommendations of the American association of thorax physicians (2012) and of the Brazilian (2013), European and American cardiology societies of cardiology (2014) are supposed to serve as basis of clinical evidence to help perioperative conducts and, consequently, to guarantee more safety to patients. 5,14-16 In this sense, this study is an attempt to assess the factors associated with inadequate management of antiplatelet agents in the perioperative period of non-cardiac surgeries based on the existing Brazilian guidelines. Methods Study outline, sample and data collection This is a cross-sectional study conducted in a high- complexity hospital, which is reference in cardiology and has internal hospital accreditation. That hospital unit contains 150 beds and, during the study period, 650 non-cardiac surgeries per month were performed on average. In the study patients submitted to non-cardiac surgeries and who previously and regularly used at least one platelet agent for primary or secondary prevention were included, which composed a sample obtained by convenience instead of probabilistic, composed of adult patients (18 years old or older). Data were collected from October 2014 to October 2016 by means of interviews with patients, or with their companions, before they were submitted to surgical procedures, using a questionnaire specific to obtain data. The interviews were held by a team of professionals and academics previously trained who attended the Departments of Pharmacy and Medicine of a public university and the Department of Pharmacy of a private university. Variables and data analysis Descriptive analysis of the variables was done by determining absolute and relative frequencies for qualitative variables, and the means for quantitative variables. In the univariate and multivariate analyses the preoperative therapy with aspirin or clopidogrel was defined the dependent variable, which is inadequate according to the SBC recommendations (yes or no), once the study was conducted in Brazil. For this variable firstly was determined whether the patients had used antiplatelet agent for primary and secondary prevention, and then whether the recommendations disposed in the SBC guidelines referring to antiplatelet agents and anticoagulants in cardiology had been met, those adopted by the institution as reference at the time of the study, as presented in Box 1. Independent variables are described in Table 1. Patients were deemed to have a history of revascularization procedure if they had already been submitted to percutaneous coronary intervention or surgical revascularization. Patients were deemed dyslipidemic when they used medicines such as statins, resins, ezetimibe or fibrates, which the V Brazilian Guideline of Dyslipidemia and Atherosclerosis Prevention (2013) deems treatments of choice for dyslipidemia, 17 additionally, patients were deemed hypertensive when at their medical records there was this information and because they used anti-hypertensive medicines, as described in the 7 th Brazilian Guideline of Arterial Hypertension (2016). 18 For the Body Mass Index (BMI), patients who had 18.5- 24.9 Kg/m 2 BMI 19 were considered having normal weight. As to a surgery’ intrinsic risk of cardiac complications, the 3 rd SBC Guideline of Perioperative Cardiovascular Assessment 20 was adopted as reference 20 . We conducted univariate analyses using the Pearson chi-square test or Fisher exact test with expected frequency equal or lower than five. All variables were included in the multivariate model which, on its turn, was done with logistic regression. Multivariate analysis was based on the odds ratio (OR) value and its respective 95% confidence interval (CI 95% ), estimated by logistic regression. A 5% level of statistical significance was the criterion adopted to identify characteristics independently associated with the dependent variable. The likelihood-ratio test was used to compare the models, and the final models’ properness was assessed with the Hosmer-Lemeshow test. All statistical analyses were done with the Stata® statistic software package, version 12. Ethical aspects This investigation was registered in the National Council of Ethics in Research – CONEP with the Certificate of Submission for Ethical Appreciation – CAAE no. 33899914.2.0000.5546, Box 01 – SBC recommendation (2013) as to using aspirin and clopidogrel in the preoperative period of non-cardiac surgery Indications References Patients using aspirin for secondary prevention in schedule of non-cardiac operations should keep using aspiring in a smaller dose (75 to 100 mg/day), except in neurosurgeries and transurethral resection of the prostate. 25,28 Patients using aspirin for primary prevention should suspend it 7 days before the procedure. For patients using clopidogrel as primary prevention, its use should be suspended 5 days before the surgical procedure. 26 For patients using clopidogrel for secondary prevention, the bleeding risk should be considered. When the bleeding risk is moderate or high, clopidogrel should be suspended 5 days before the procedure, but when the bleeding risk is low, the antiplatelet agent should be maintained. 29 ASPIRIN: acetylsalicylic acid. 597