Does Terminal Warm Blood Cardioplegia Improve Myocardial Preservation during Coronary Arterial Bypass Grafting? / 日本心臓血管外科学会雑誌

We investigated the clinical results of coronary arterial bypass grafting (CABG), using a terminal warm blood cardioplegia (TWBCP) for myocardial preservation. In the past 6 years, 102 cases of CABG have been performed at our institution. These 102 cases were divided into the following two groups; (1) Group T, consisting of 41 cases, in which TWBCP was employed; (2) Group non-T, consisting of 61 cases, in which TWBCP was not employed. We performed a comparative study between the groups on the perioperative cardiac function and so on. Between the two groups, there were no significant differences in age, gender, preoperative ejection fraction (EF), operative time, cardiopulmonary bypass time (CPBT) and the level of CPK-MB. In group T, the number of grafts was significantly more than that in group non-T (<i>p</i>=0.002). Aortic cross-clamp time was significantly longer in group T. However, the duration of assisted circulation after aortic declamp was significantly longer in group non-T than that of group T (<i>p</i>=0.01). The incidence of ventricular fibrillation after release of aortic clamp in group T was 9.8%, while it was 67.2% in group non-T, showing a significant difference. Furthermore, the postoperative cardiac index in group T was significantly higher than that in group non-T. These results suggest that it is important for the myocardium, to recover from its ischemic damage caused by VF after release of aortic cross-clamp. In conclusion, we consider it effective to employ TWBCP in CABG to improve postoperative cardiac function.

Beneficial Effect of Terminal Warm Blood Cardioplegia and Controlled Aortic Root Reperfusion during Isolated Aortic Valve Replacement / 日本心臓血管外科学会雑誌

Left ventricular hypertrophy in patients with aortic valve disease has long been recognized as a significant risk factor for aortic valve replacement. Higher operative mortality in such patients has been attributed to poor myocardial preservation. In these patients improvement of left ventricular subendocardial blood flow during reperfusion seems to be mandatory to avoid subendocardial injury. Therefore, we attempted to increase subendocardial blood flow during reperfusion by terminal warm blood cardioplegia (TWBCP) followed by controlled aortic root reperfusion (CARR) in patients requiring isolated aortic valve replacement. The patients with TWBCP and CARR had a tendency towards severe left ventricular hypertrophy and more advanced NYHA function class compared to those with hypothermic cardioplegia alone. Nevertheless, the patients with TWBCP and CARR showed significantly better recovery of left ventricular function, i.e., spontaneous recovery of beating and higher cardiac index as well as left ventricular stroke work index, despite significantly less catecholamine support. These resuls suggest that TWBCP followed by CARR may offer significant benefits over unmodified reperfusion during aortic valve replacement for patients with severe left ventricular hypertrophy.