L-arginine effects on myocardial stress in cardiac surgery: preliminary results

Luisa Colagrande1, Francesco Formica, Fabiano Porta

  • 1Surgical Science and Intensive Care Department, Cardiac Surgery Clinic, University of Milan-Bicocca, San Gerardo Hospital, Monza, Italy. lcolagrande@yahoo.it

Insights

Adding L-arginine to cardioplegia during coronary artery bypass grafting reduced myocardial stress and improved patient outcomes. This intervention decreased inflammatory markers and platelet activation, suggesting enhanced myocardial protection.

Area of Science:

  • Cardiology
  • Cardiac Surgery
  • Biochemistry

Background:

  • L-arginine enhances nitric oxide release, improving coronary blood flow and reducing platelet activation.
  • Myocardial damage and stress during cardiac surgery are significant concerns.
  • Investigating L-arginine's role in cardioplegia aims to mitigate these surgical complications.

Purpose of the Study:

  • To assess the feasibility and efficacy of adding L-arginine to antegrade and retrograde blood cardioplegia.
  • To determine if L-arginine reduces myocardial damage and stress during coronary artery bypass grafting (CABG).
  • To evaluate the safety and impact of L-arginine on hemodynamic parameters and inflammatory markers.

Main Methods:

  • Twenty-eight CABG patients were randomized to receive L-arginine in cardioplegic solution.
  • Hemodynamic parameters (cardiac index, vascular resistances, wedge pressure) were monitored.
  • Blood samples analyzed for inflammatory markers (IL-2 receptor, IL-6, TNF-alpha), cardiac enzymes (CK-MB, troponin T), and cell counts (platelets, leukocytes).

Main Results:

  • The L-arginine group showed statistically significant reductions in IL-2 receptor, IL-6, TNF-alpha, platelets, and leukocytes.
  • Trends towards decreased creatine kinase-MB mass and troponin T levels were observed.
  • Postoperative systemic vascular resistances and pulmonary capillary wedge pressure were lower in the L-arginine group.

Conclusions:

  • Addition of L-arginine to cardioplegia demonstrates positive effects in reducing myocardial stress.
  • L-arginine may improve patient outcomes by potentially reducing the need for inotropic support.
  • Reduced platelet and leukocyte counts suggest decreased no-reflow phenomenon and endothelial protection.
Abstract