A clinical comparative study between crystalloid and blood based St Thomas' hospital cardioplegic solution

Objective: Myocardial protection with blood cardioplegia during cardiac sur gery is increasingly preferred, but few studies have compared the protectiv e effects of crystalloid cardioplegia to the same solution with blood as th e only variable. This clinical study compared the protective effects of cry stalloid or blood-based St. Thomas' Hospital cardioplegic solution No. 1. M ethods: Fifty higher risk patients undergoing elective coronary artery bypa ss surgery, with an ejection fraction less than 40%, were randomly allocate d to receive cold (4 degrees C) intermittent crystalloid St. Thomas' No. 1 cardioplegia (n = 25), or a similar blood-based solution (n = 25) with a ha ematocrit of 10-12%. We determined (1) peri-operative and post-operative ar rhythmias, (2) left and right ventricular function (24 h) using the thermod ilution technique, (3) left ventricular high-energy phosphate content sampl ed before ischaemia, the end of ischaemia and the end of bypass. Results: P re-operative haemodynamic data, aortic cross-clamp and bypass times were si milar in both groups of patients; there was no mortality. At the end of isc haemia there were no differences in ATP content between groups but creatine phosphate was maintained at a significantly (P < 0.007) higher level in th e blood-based St. Thomas' cardioplegia group than the crystalloid St. Thoma s' cardioplegia group (20 +/- 2 (SE) vs. 13 +/- 1 mu mol/g dry wt, respecti vely). Return to spontaneous sinus rhythm was significantly (P = 0.002) inc reased in the blood-based St. Thomas' cardioplegia group (96%) compared to the crystalloid St. Thomas' cardioplegia group (60%). Early post-operative ventricular dysfunction occurred in bath groups, but normal LV function (st roke work index) recovered significantly (P = 0.043) more rapidly (by 2 h) in the blood-based St. Thomas' cardioplegia group of patients. Conclusions: In a higher risk (EF < 40%) group of patients undergoing elective cardiac surgery, addition of blood to an established crystalloid cardioplegic solut ion significantly enhanced myocardial protection by reducing arrhythmias, i mproving rate of recovery of function and maintaining myocardial high-energ y phosphate content during ischaemia. (C) 1999 Elsevier Science B.V. All ri ghts reserved.