Strategies for myocardial protection during open heart surgeries are desired. Several experimental studies have shown beneficial effects of remote ischemic preconditioning (RIPC). The underlying mechanisms are not totally understood. This study intends to evaluate molecular mechanisms involved with RIPC on myocardium of patients underwent open heart surgeries.

Inclusion Criteria:

• Patients older than 18 years
• Scheduled for coronary artery bypass grafting with or without valve replacement associated
• Use of blood cardioplegia
• EuroSCORE II greater than or equal to 1.0%

Exclusion Criteria:

• History of cardiogenic shock
• Complications in the admission
• Pregnant patients
• Severe peripheral arterial disease affecting the upper limbs
• Liver failure (bilirubin ˃ 20 mmol / L, INR 2.0 ˃)
• Significant pulmonary disease (˂ FEV1 40%)
• Renal failure with glomerular filtration rate ˂ ml/min/1,73 m²
• Concomitant treatment with glibenclamide or nicorandil (medications that interfere with cardioprotection induced by IPCR)