Remote Ischemic Preconditioning in Patients Undergoing Isolated Aortic Valve Replacement Surgery

Remote Ischemic Preconditioning in Patients Undergoing Isolated Aortic Valve Replacement Surgery With a Biological Prosthesis: A Single Center Randomized Prospective Study

The goal is to investigate the efficacy, safety and possible neuro- and cardioprotective effects of remote ischemic preconditioning (RIPC) in adult cardiac patients undergoing isolated aortic valve replacement surgery with a biological prosthesis. Neuropsychological evaluation preoperatively and at 30d after surgery will establish if there are any differences in neuropsychological performance between groups. A large array of biochemical markers will be analyzed from plasma samples taken at different time points. Additionally skin biopsies from the lower limb will be taken before and after performing RIPC on said limb. During the venous cannulation phase a atrial biopsy will be taken. The biochemical markers from plasma and tissue samples will be used to asses brain tissue damage, inflammation and cardiac tissue damage between groups. This will be a single center prospective randomized study with two groups. A intervention group (RIPC) and a control group. Study size is: 40 patients in total, 20 patients per group.

Patient will undergo normal isolated aortic valve replacement surgery with a biological prosthesis and a preoperative lower leg remote ischemic preconditioning(RIPC) phase.

A blood pressure cuff is placed around the right leg on the level of the thigh. Randomization is performed after this, using sealed envelopes with covariate balancing for age and sex. Regardless of the outcome of the randomization the cuff is left in place so as not to give any indication of which group the patient belongs to. If the patient is randomized into the remote ischemic preconditioning group (RIPC) then four (4) cycles of five (5) minute inflation are given after induction. Each cycle is followed by a five (5) minute interval of reperfusion. Cuff pressure should be 200mgHg at least (RRsyt + 100mmgHg) during the inflation periods.

Investigators will use a neuropsychological test battery to test our subject pre- and post-operatively. A qualified psychologist will administer the test battery. The test battery will be relatively simple but still have several different tests. These tests will include but are not limited to: - Trail Making test A & B (TMT)

A bioplex/multiplex assay of systemic inflammatory response markers and other cytokines including but not limited to: Tumor Necrosis Factor-a, Interleukin-1b, -2, -4, -5, -6. C-Reactive Protein, Hypoxia inducible Factor -1.

A bioplex/multiplex assay of neuronal and cardiac tissue specific biomarkers including but not limited to: S-100b, Glial Fibrillary acidic protein, Neuron Specific enolase, Troponin-I, Brain Natriuretic Peptide, Creatinine Kinase - MB

Inclusion Criteria: Non-emergency aortic valve replacement with a biological prosthesis with perfusion and cardiac arrest Exclusion Criteria: Recent myocardial infarction Carotid stenosis requiring intervention Any other concomitant surgical procedure Increased troponin baseline before surgery Critical ischemia of lower limbs Peripheral arterial disease (ASO, media sclerosis) Morbid obesity (Incompatible cuff-to-thigh diameter) Severe heart insufficiency Moderate to severe venous insufficiency lower limbs Recent acute stroke <90d Difference in cardioplegic protocol Diseased aorta in epiaortic ultrasound