Choice of mechanical support for fulminant myocarditis: ECMO vs. VAD?

renal failure were not reduced in off-pump coronary artery bypass surgery. But, the atrial fibrillation was reduced significantly by eliminating CPB [2]. We should emphasize that until recent years generally selected patients underwent OPCAB. With growing surgical experience, indication for OPCAB has been changing over the last few years and patients with multi-vessel grafts and more severely diseased vessels can now be a candidate for OPCAB. Therefore, patient selection is the most important weakness in the studies comparing OPCAB and conventional coronary artery bypass grafting (CCABG) surgery. Again we agree with Dr Raja that prospective doubleblinded randomized clinical trials (RCTs) have been allotted the highest level of evidence [3]. But, it is also difficult to design prospective double-blind randomized clinical trials concerning OPCAB and CCABG surgery due to the preference of surgeon and indication of surgical methods. Therefore, although there are some inherent weaknesses in retrospective studies which are well known, we should not ignore the results of well-designed retrospective randomized studies concerning OPCAB and CCABG surgery. In our retrospective study [4], we tried to compare the patients with similar peroperative variables. The selection of the patients with single vessel disease can help us to standardize the patients. Moreover, the patients with single vessel disease could be easily randomized. On the other hand, the results do not suffice to exclude a possible advantage of OPCABs in patients receiving multiple bypasses. But nowadays, it is still difficult to randomize the patients when you design a randomized study to compare the patients with diffusely diseased multiple vessels. When double-blind randomization is possible with growing experience, the point under consideration will be answered. Until this time, a large-scale multi-center well-designed retrospective RCT of OPCAB versus CCABG may help us to answer the question of whether OPCAB reduces the incidence of post-operative AF.