Single Dose Inamrinone in Terminal Warm Cardioplegia in On-Pump Coronary Artery Bypass Patients

Background: Phosphodiesterase inhibitors (PDI) are used in cardiac surgery to improve and stabilize cardiac function after surgery. The aim of this study is to evaluate changes in hemodynamics and early outcomes when PDI (Inocor/ inamrinone) is given in terminal warm blood cardioplegia to on-pump CABG only patients and compare results with patients who did not receive the drug. Material and Methods: From April 2003 through September 2004 241 pts underwent elective on-pump CABG only surgery. 141 pts received Inocor in the terminal warm blood cardioplegia (Group 1) and 100 pts did not (Group 2). Results: Demographic data, preoperative EuroSCORE risk scores and operative details were similar. Of pts preoperatively in sinus rhythm (SR) 80.15% in Group 1 and 69.79% in Group 2 regained spontaneous SR (p = 0.07) after release of crossclamp. Inotropic support was needed in 5 pts in Group 1 and in 12 pts in Group 2, p = 0.02. Post cardiopulmonary by-pass (CPB) IABP support was needed for 4 pts in Group 2 and none for Group 1 pts, p = 0.01. There was no operative mortality in either Group and hospital/30 day mortality was similar (3/2.13% vs 3/3.00%, p = 0.69). There were no statistical difference in stay in postoperative intensive care unit (p = 0.15), total hospital stay (p = 0.07), appearance of postoperative atrial fibrillation (p = 0.23) or appearance of postoperative kidney injury (p = 0.27). Post CPB cardiac index improved 16.90% in Group1but decreased 1.49% in Group 2, p < 0.0001. Mean arterial pressure decreased 7.46% in Group 1 pts and 5.08% in Group 2 pts, p = 0.002, but no pts in either Group needed medication for too low blood pressure. Systemic vascular resistance decreased 28.40% in Group 1 and 9.02% in Group 2, p < 0.0001. Conclusions: Inamrinone in terminal warm blood cardioplegia (hot shot) is safe and effective way to improve and stabilize cardiac function after on-pump CABG surgery but does not affect short-term outcomes.