Because the environment of space is extremely harsh, manned space activities require considerable medical support. Space medicine, a field of medical science, deals with such situations. In this report, we present the outline of a space medicine course that we have established as an elective course in the School of Medicine, the University of Tsukuba, Japan. The students' responses to questionnaires indicated the popularity of the course and their interest in it. Concentrated courses are effective for teaching new cross-disciplinary areas in medical school.

We herein review the early results of minimally invasive coronary artery bypass (MIDCAB). From April 1994 to November 1998, 23 patients underwent MIDCAB, and 12 patients underwent coronary artery bypass grafting with cardiopulmonary bypass (CABG). We compared and analyzed the findings of these two groups. Regarding preoperative factors, the MIDCAB group included elderly patients, while the CABG group consisted of younger patients. However, the frequency of hemodialysis, respiratory disorders and cerebral vascular accidents did not differ significantly between the 2 groups. Regarding perioperative factors, the MIDCAB group needed a shorter operation time, and also had a lower bleeding volume, and a low incidence of blood transfusion. Regarding the postoperative course, the MIDCAB group needed a shorter artificial respiration time, and a shorter postoperative hospital stay, and no mortality was observed. The graft patency of the MIDCAB group was lower (88%) than the CABG group (100%). However, the graft patency of the MIDCAB group reached 94% after we used a stabilizer in the operation. In conclusion, the operation results of the MIDCAB group were comparatively better than those of the CABG group. Thanks to recent technological advances, the results of MIDCAB continue to improve. Though MIDCAB remains an invaluable operative modality for the treatment of one-vessel disease, surgeons must be careful to select appropriate candidates for this operative method.

A 47-year-old man was admitted with symptoms of angina pectoris. After evaluating the patient, coronary artery bypass grafting (CABG) was performed. First, the left internal thoracic artery (LITA) was grafted to the obtuse marginal branch (OM), and then the right gastroepiploic artery (RGEA) was grafted to the posterior descending branch (PD). Just after completing anastomosis, we performed intraoperative thermal coronary angiography. The RGEA-PD was patent. However, the LITA-OM was not patent on thermal coronary angiography. After a re-anastomosis was done at the LITA-OM, thermal coronary angiography was again performed and the LITA-OM was found to be patent. The postoperative course was uneventful, and all grafts were patent on postoperative angiography. In conclusion, intraoperative thermal coronary angiography was found to be useful for CABG.

Background and Objectives: Recent guideline recommends evaluation using of coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in patients with functionally insignificant stenosis. We evaluated clinical implications of CFR and IMR in patients with high fractional flow reserve (FFR) and deferred revascularization. Methods: A total of 867 patients (1,152 vessels) consigned to deferred revascularization who underwent comprehensive physiologic assessments were enrolled. Patients with high FFR (>0.80) were categorized by CFR (≤2) and IMR (≥23 U). Clinical outcome was assessed by patient-oriented composite outcome (POCO), a composite of any death, myocardial infarction (MI), and revascularization at 5 years. Results: Patients with low CFR (≤2) showed significantly greater risk of POCO than those with high CFR (>2) in both high-FFR (p=0.024) and low-FFR (p=0.034) groups. In patients with high FFR, those with low CFR and high IMR (overt microvascular disease) displayed the greatest risk of POCO overall (p=0.015), surpassing those with high CFR and low IMR (HR, 2.873; 95% CI, 1.476–5.594; p=0.002) and showing significantly greater risk of cardiac death or MI (HR, 5.662; 95% CI, 1.984–16.154; p=0.001). Overt microvascular disease was independently associated with POCO in the high-FFR population (HR, 2.282; 95% CI, 1.176–4.429; p=0.015). Conclusion Among patients with deferred revascularization, those with low CFR showed significantly greater risk of POCO than those with high CFR, regardless of FFR. In patients with high FFR, those with overt microvascular disease showed significantly greater risk of POCO and cardiac death or MI at 5-year, compared with the others.

Background and Objectives: The influence of pre-intervention coronary physiologic status on outcomes post percutaneous coronary intervention (PCI) is not well known. We sought to investigate the prognostic implications of pre-PCI fractional flow reserve (FFR) combined with post-PCI FFR. Methods: A total of 1,479 PCI patients with pre-and post-PCI FFR data were analyzed. The patients were classified according to the median values of pre-PCI FFR (0.71) and post-PCI FFR (0.88). The primary outcome was target vessel failure (TVF) at 2 years. Results: The risk of TVF was higher in the low pre-PCI FFR group than in the high pre-PCI FFR group (hazard ratio, 1.82; 95% confidence interval, 1.15–2.87; p=0.011). In 4 group comparisons, the cumulative incidences of TVF at 2 years were 3.8%, 4.1%, 4.8%, and 10.2% in the high pre-/high post-, low pre-/high post-, high pre-/low post-, and low pre-/low post-PCI FFR groups, respectively. The risk of TVF was the highest in the low pre-/low post-PCI FFR group among the groups (p values for comparisons <0.05). In addition, the high pre-/low post-PCI FFR group presented a comparable risk of TVF with the high post-PCI FFR groups (p values for comparison >0.05). When the prognostic value of the post-PCI FFR was evaluated according to the pre-PCI FFR, the risk of TVF significantly decreased with an increase in postPCI FFR in the low pre-PCI FFR group, but not in the high pre-PCI FFR group. Conclusions Pre-PCI FFR was associated with clinical outcomes after PCI, and the prognostic value of post-PCI FFR differed according to the pre-PCI FFR.