Long term left ventricular systolic function assessment following CABG. A prospective, randomised study. Blood versus cristalloid cardioplegia.

BACKGROUND

In an effort to define the role of blood cardioplegia delivered in antegrade/retrogade fashion in patients with either good or poor left ventricular function undergoing elective coronary artery bypass surgery, we initiated a prospective randomised study in which postoperative hemodynamics besides clinical data were compared in patients administered antegrade/retrograde crystalloid cardioplegia.

METHODS

To compare the efficiency of two methods of myocardial protection--cold crystalloid ante/retro cardioplegia and cold blood ante/retro cardioplegia in two groups of patients with high and low LVEF--we randomised 122 patients for CABG. The potential improvement in left ventricular systolic function assessed by echocardiography and the same clinical data were the end points of the study. Patients were divided into group I (47 patients, LVEF <40%) and group II (75 patients, LVEF >40%). Pathologic antecedents and preoperative clinical conditions were similar in both randomised subgroups Ia, IIa (crystalloid cardioplegia) and subgroups Ib, IIb (blood cardioplegia). The following parameters were measured: left atrium diameter (LA), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), left ventricular wall motion score index (WMSI), and area asynergy (AA). All patients underwent echocardiography: A--prior the CABG, B--2-6 weeks postoperatively, C--3 months postoperatively, D--6 months postoperatively, E--1 year postoperatively.

RESULTS

The results of clinical assessment in both groups showed improvement of quality of life. The constant improvement of LVEF and WMSI was observed in group I in contrast to group II. There were no significant differences in postoperative left ventricular systolic function between subgroups Ia and Ib or IIa and IIb.

CONCLUSIONS

The use of blood cardioplegia, instead of crystalloid cardioplegia, when used in the ante/retrograde fashion during CABG has no influence on postoperative left ventricular systolic function. The improvement in left ventricular systolic function following CABG is greater in patients with low LVEF in contrast to patients with high LVEF.