Comparison Between Blood and Crystalloid Cardioplegia in Patients with Left Ventricular Dysfunction Undergoing Coronary Surgery

Cold blood cardioplegia reduces the increase in cardiac enzyme levels compared with cold crystalloid cardioplegia in patients undergoing aortic valve replacement for isolated aortic stenosis

OBJECTIVES

Cardiac arrest during cardiac surgery is most commonly induced by cold blood or cold crystalloid cardioplegia. The results from clinical studies are divergent regarding which of the 2 solutions provides better myocardial protection. This might be explained by several factors. Both heterogeneity in disease for the included patients and the fact that most studies are retrospective in design and that patients with coronary artery disease with different degrees of myocardial ischemia are included might explain these findings. To circumvent these potentially confounding factors, we included in a prospective randomized study only patients undergoing aortic valve replacement for aortic stenosis without other significant cardiac disease. Patients were randomized to antegrade cold crystalloid or cold blood cardioplegia.

METHODS

Eighty patients with aortic stenosis undergoing aortic valve replacement without significant coronary artery stenosis or other significant concomitant heart valve disease were included in the study. They were randomized to either antegrade cold blood or cold crystalloid cardioplegic solution delivered through the coronary ostia every 20 minutes throughout the period of aortic crossclamping. Maximum postoperative creatine kinase isoenzyme MB and troponin-T levels, well-established markers of myocardial damage, were compared between the 2 groups.

RESULTS

Both maximum postoperative creatine kinase isoenzyme MB and troponin-T levels were significantly higher by approximately 100% in the cohort of patients receiving crystalloid compared with blood cardioplegia. Only in the group of patients receiving cold crystalloid cardioplegia was there a positive correlation between cardiac enzyme levels and crossclamp time.

CONCLUSION

Antegrade cold blood cardioplegia provides better myocardial protection than cold crystalloid cardioplegia in patients undergoing aortic valve replacement.

Myocardial revascularisation in patients with severe left ventricular dysfunction. Early and midterm results

AIMS

This retrospective study evaluates early and midterm results in patients with severe left ventricular dysfunction.

TECHNIQUE

Ninety-seven consecutive patients with coronary artery disease and ejection fraction of left ventricle (LVEF) less or equal to 25 % underwent elective coronary artery bypass graft procedure between September 1998 and December 2001. Mean age at operation was 66 (47-86) years. The main symptoms were angina class III-IV Canadian Cardiovascular Society (CCS) in 78 patients (80 %) and dyspnoea class III-IV New York Heart Association (NYHA) in 43 patients (44 %). The major indications for surgery were severe angina, dyspnoea in 90 patients (93 %). Cardiac index (CI), echocardiography (ECHO), planimetry, end-diastolic pressure of left ventricle (LVEDP), end-diastolic diameter of left ventricle (LVEDd) were used to access left ventricular function preoperatively. ECHO was also used to access left ventricular function postoperatively.

RESULTS

Early postoperative (30 days) mortality was 4.1 %. Complications had 25 patients (26 %) postoperatively. Two years survival was 95.7 %. Class III-IV CCS and/or NYHA had 17 patients (17.5 %) two years after surgery. LVEF (assessed by ECHO) improved from 23.1 % preoperatively to 36.0 % postoperatively (p < 0.05).

CONCLUSION

The study showed that elective myocardial revascularisation in patients with severe left ventricular dysfunction and signs of myocardial viability is not necessarily associated with high operative mortality. It can be performed safely with respectable midterm survival in concordance with left ventricular function improvement, symptom relief and quality of life improvement.