Association of PeriOPerative Aspirin-ResisTance and CardioVascular Outcome

Study Overview
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Brief Summary
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The aim of our study is to investigate the association between perioperative aspirin resistance and Myocardial Injury after Non-cardiac Surgery (MINS) in patients undergoing vascular surgery.

Detailed Description
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Because of new surgical techniques, advanced monitoring modalities and improvements in perioperative care, perioperative mortality and morbidity have been significantly reduced in the last decades; however, patients still suffer from high perioperative mortality and morbidity, especially those with pre-existing cardiovascular diseases. Not only perioperative myocardial infarction but also myocardial injury after non-cardiac surgery, which presents without clinical symptoms, is associated with an adverse outcome. Possibilities to preoperatively identify patients at cardiovascular risk are limited and prophylactic interventions are not yet established or controversial. Aspirin is used for primary and secondary prevention in cardiovascular diseases. New-onset increased platelet function on aspirin treatment (aspirin resistance) has been demonstrated in cardiac and vascular surgery. Yet, it has not been investigated whether a new perioperative aspirin resistance is associated with higher risk of myocardial injury after non-cardiac surgery (MINS) and cardiovascular events. The aim of this study is to evaluate a potential association between new-onset aspirin resistance and MINS in patients undergoing vascular surgery. If there is an association of perioperative aspirin resistance and MINS during vascular surgery, the detection of perioperative aspirin resistance could be used as perioperative risk stratification tool in order to improve clinical risk stratification and reduce perioperative morbidity and mortality. Therefore, 220 patients treated with aspirin and scheduled for vascular surgery will be recruited. Blood will be drawn at predefined time points before surgery and up to three days postoperatively. Aspirin resistance will be measured by Multiplate Analyzer prior to surgery, one hour after skin-incision, four hours after surgery and on post-OP days one and two. Adverse cardiovascular events will be recorded until 30 days post-OP. ECGs will be recorded preoperatively and on post-OP day 3. High-sensitive cardiac Troponin T will be measured prior to surgery and on post-OP days one to three. Patient charts will be screened and a telephone interview will be performed to detect cardiovascular events after discharge until post-OP day 30.

Official Title
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Association of PeriOPerative Aspirin-ResisTance and CardioVascular Outcome

Conditions
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Vascular Surgery

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Preoperative aspirin treatment at least 14 days prior to surgery Elective vascular surgery In-patient treatment Informed consent Exclusion Criteria: 17 years of age or younger Known pregnancy or breastfeeding Missing informed consent Ambulatory or day-case surgery Emergency surgery Current clopidogrel or non-steroidal anti-inflammatory drug treatment Preoperative aspirin resistance Current thrombocytopenia (<100000 platelet/µl) Liver or renal failure (GOT/GPT and/or creatinine increased >2-fold) Entity which is part of the composite endpoint diagnosed within past 28 days Angiography without surgical intervention

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial Injury after Non-cardiac Surgery | Number of participants with MINS defined as raise in postoperative hs-cTNT (high sensitivity cardiac troponin T) judged due to myocardial ischemia detected at postoperative visits, documented in patient chart or detected during telephone interview after 30 postoperative days. | 30 days postoperative | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Composite of Cardiovascular Events | Number of participants with Cardiovascular Events defined as occurrence of Cardiac Death and/or Myocardial Ischemia and/or Myocardial Infarction and/or Embolic Stroke and/or Thrombotic Stroke recorded until postoperative day 30. Definitions according to European Perioperative Clinical Outcome-(EPCO) detected at postoperative visits, documented in patient chart or detected during telephone interview after 30 postoperative days | 30 days postoperative | 
| Peripheral vascular occlusion | Diagnosed by a radiologist based on the results of duplex ultrasonography, angiography or CT-angiography. | 30 days postoperative | 
| Mesenteric ischemia | Diagnosed by a radiologist based on the results of angiography or CT-angiography. | 30 days postoperative | 
| New-onset atrial fibrillation | Number of participants with new electrocardiographic detection of atrial fibrillation in postoperative ECG and/or documented in patient chart | 30 days postoperative | 
| Congestive heart failure | Number of participants with congestive heart failure according to European Perioperative Clinical Outcome (EPCO) definitions | 30 days postoperative | 
| Cardiac death | Number of participants with cardiac death defined as death due to new myocardial infarction or ischemia, or atrial or ventricular arrhythmias, or cardiogenic pulmonary edema, or pulmonary embolism detected at postoperative visits, documented in patient chart or detected during telephone interview after 30 postoperative days | 30 days postoperative | 
| Myocardial Ischemia | Number of participants with myocardial ischemia defined as new electrocardiographic detection of myocardial ischemia in ECG and/or documented in patient charts which will be screened up to 30 postoperative days and/or detected during telephone interview after 30 postoperative days | 30 days postoperative | 
| Myocardial Infarction | Number of participants with myocardial infarction defined as an increase in serum cardiac biomarker values in combination with symptoms of ischemia or new/presumed new significant ST segment or T wave ECG changes or new left bundle branch block or development of pathological Q waves on ECG. Definition according to European Perioperative Clinical Outcome-(EPCO) detected at postoperative visits, postoperative blood analyses, documented in patient chart or detected during telephone interview after 30 postoperative days | 30 days postoperative | 
| Stroke | Number of participants with embolic or thrombotic stroke defined as cerebral event with persistent residual motor, sensory or cognitive dysfunction detected at postoperative visits, documented in patient chart or detected during telephone interview after 30 postoperative days. | 30 days postoperative | 
| Length of hospital stay | Documented in patient charts. | 30 days postoperative | 
| Length of intensive care unit stay | Documented in patient charts. | 30 days postoperative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vascular surgery, aspirin resistance, MINS