COMPARISON OF STANDARD (NONOXYGENATED) VS OXYGENATED ST THOMAS HOSPITAL CARDIOPLEGIC SOLUTION NO-2 (PLEGISOL)

Recent studies have suggested that oxygenation of crystalloid cardioplegic solutions improves myocardial preservation. To assess whether oxygenation of St. Thomas' Hospital cardioplegic solution No. 2 (Plegisol) improves its clinical efficacy, 50 patients were randomly assigned into 2 groups: (1) those receiving Plegisol and (2) those receiving O2-Plegisol (PO2 > 500 mmHg at 4 °C). Efficacy was assessed by (a) clinical and haemodynamic parameters, (b) quantitative birefringence changes in response to ATP and calcium as a measurement of myocardial preservation in left and right ventricular biopsies, (c) creatine kinase (MB isoenzyme) release for up to 4 days postoperatively, (d) electrocardiographic (ECG) monitoring for up to 7 days postoperatively. There were no differences in mean age, ejection fraction, aortic crossclamp duration, or bypass duration between the 2 groups of patients. In the Plegisol group, 2 patients (8%) died and 4 patients (16%) required inotropic support, whereas in the O2-Plegisol group there were no deaths and only 2 patients (8%) required inotropic support. These differences, however, were not statistically significant. Birefringence assessment demonstrated an improved myocardial response to ATP and calcium (predominantly in the left ventricular epimyocardium and in the right ventricular biopsies) at the end of ischaemia and after reperfusion in patients given O2-Plegisol. Deterioration in cellular assessment of myocardial contractility (measured by a reduction in birefringence of > 0.4 nm) was reduced from 20% in Plegisol patients to 12.5% in O2-Plegisol patients. CK-MB values showed no difference at any sampling time between the 2 groups of patients; a mean peak CK-MB of 35 IU/loccurred 2 h postoperatively. Post-operative ECG monitoring demonstrated a trend towards a reduced incidence of conduction disturbances in O2-Plegisol patients; however, due to the small number of patients involved, statistical differences were not observed. Oxygenation of the St. Thomas' Hospital cardioplegic solution No. 2 (Plegisol) tended to be beneficial in terms of postoperative myocardial preservation and reduced conduction disturbances. © Springer-Verlag.