COMPARISON OF RETROGRADE VERSUS ANTEGRADE COLD BLOOD CARDIOPLEGIA - RANDOMIZED TRIAL IN ELECTIVE CORONARY-ARTERY BYPASS PATIENTS

Objective: Myocardial areas distal to complete coronary artery occlusi on an poorly protected by antegrade cardioplegia. Hence, retrograde ca rdioplegia becomes an important adjunct in myocardial protection. An a im of the study was to compare both methods prospectively. Methods: 15 8 coronary artery bypass grafting (CABG) patients were randomly assign ed to two groups according to myocardial protection technique: 89 pati ents to group 1-retrograde cold blood cardioplegia (RCBC); and 69 pati ents to group 2-antegrade cold blood cardioplegia (ACBC). Preoperative parameters were similar but cross-clamp time and volume of cardiopleg ia needed were higher in the retrograde group. The results were assess ed on the basis of: (1) clinical outcome; (2) ECG and enzymatic parame ters of ischemia, (3) assessment of early systolic function by means o f cardiac output (CO), stroke work index (SWI), left ventricular strok e work index (LVSWI) and right ventricular stroke work index (RVSWI) t aken before, and 1 and 5 h after coming off bypass; (4) late systolic and diastolic function by echo assessment of segmental contractility o f 17 segments and indexes of peak transmitral flow (TMI) taken 7 days and 6 months after operation. Results: Ischemic events, inotropes and ventricular fibrillation on reperfusion were significantly more freque nt in the antegrade group. Sinus rhythm al an early stage postoperativ ely was found more frequently in the retrograde group. All these param eters became comparable 24 h after operation. Early myocardial recover y was better in the retrograde group where intraoperative improvement in CO and SWI was significant. At the same time, SWI decreased signifi cantly in the antegrade group. RVSWI changes were similar in both grou ps. There were no differences in mortality and perioperative MI. Late myocardial performance by segmental contractility and diastolic transm itral flow were similar in both groups. Conclusions: Retrograde contin uous blood cardioplegia reduces ischemic injury and permits better ear ly recovery of myocardial function. There is no difference, however, r egarding long-term assessment of myocardial recovery. (C) 1997 Elsevie r Science B.V.