Remote Ischemic Preconditioning Prior to Vascular Surgery

Study Overview
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Brief Summary
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The investigators have previously shown that elective vascular surgery is a high-risk operation with an anticipated risk of either death or heart attack of 15%. This study is testing whether a protocol of remote ischemic preconditioning (RIPC) applied 24 hours prior to the operation is safe, feasible and reduces the incidence of an adverse, perioperative cardiac complication.

Detailed Description
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The proposed investigation has a single blind, randomized design and plans to enroll 180-205 patients who are scheduled to have major, elective vascular surgery for occlusive carotid disease, expanding abdominal aortic aneurysm (AAA), occlusive lower extremity disease and/or critical limb ischemia at the Minneapolis VA Health Care Center. 24 hours prior to the patient's scheduled vascular operation, RIPC therapy will be applied to one of the participant's upper arms to cause forearm ischemia. Clinically collected, pre-operative troponins, creatine kinase MBs (CK-MBs), EKGs along with troponins, CK-MBs and EKGs collected on day 1, 2, 3 and day 7 (if still hospitalized) will be utilized to evaluate the occurrence of perioperative, adverse cardiac events.

Official Title
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Cardiac Remote Ischemic Preconditioning Prior to Elective Major Vascular Surgery

Conditions
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Peripheral Arterial Disease, Vascular Surgery

Intervention / Treatment
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* Procedure: Preconditioning
* Procedure: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Undergoing elective major vascular surgery at the Minneapolis VA Medical Center for abdominal aortic aneurysm, carotid disease or limb ischemia. Age > 18. Provides informed consent. Exclusion Criteria: Hypertensive crisis Peripheral arterial disease of the upper extremities Arteriovenous (AV) fistula Acute Coronary Syndrome (ACS) in the last 6 months Severe valvular heart disease Pregnant women Unable to provide consent

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Sham<br>Blood pressure cuff inflated to 40-50 mmHg in the upper extremity | Procedure: Control<br>* Blood pressure cuff inflated to 40-50 mmHg in the upper extremity<br>|
| Experimental: RIPC<br>Blood pressure cuff inflated to 200 mmHg in the upper extremity for 5 minutes to cause forearm ischemia by external compression of the brachial artery. This will be followed by 5 minutes of cuff deflation to allow for preperfusion. The ischemia-reperfusion cycle will be repeated 3 times for a total duration of 30 minutes, equally divided between ischemia and reperfusion. | Procedure: Preconditioning<br>* Blood pressure cuff inflated to 200 mmHg in the upper extremity for 5 minutes to cause forearm ischemia by external compression of the brachial artery. This will be followed by 5 minutes of cuff deflation to allow for preperfusion. The ischemia-reperfusion cycle will be repeated 3 times for a total duration of 30 minutes, equally divided between ischemia and reperfusion.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Troponin I Elevation Above the Upper Reference Limit (URL) | Troponin I is a biomarker of myocardial necrosis that may indicate myocardial damage or injury that occurs during the perioperative period | Within 3 days of the vascular operation |