松橋 和己

As the current guidelines on myocardial revascularization recommend, transit-time flow measurement (TTFM) is increasingly used for intraoperative graft flow analysis during coronary artery bypass grafting (CABG) as a less invasive, more highly reproducible, and less time-consuming method. In addition to the morphological assessment using color Doppler, mean graft flow (Qm) > 15 ml/min, pulsatility index (PI) < 5.0, diastolic filling (DF) > 50%, and systolic reverse flow (SRF) < 4% have been reported to predict patent CABG grafts. However, it is difficult to determine the clear-cut cut-off value of these parameters, because they varies with the hemodynamic characters, including fractional flow reserve (FFR) of the target coronary artery. In addition to these parameters, we focused on fast Fourier transform (FFT) analysis, because the TTFM waveform morphology may be more important than Qm itself. FFT analysis is based on the principle that any periodic waveforms can be broken down into a series of pure sine waves or harmonics. Herein we review FFT analysis of the intraoperative TTFM waveforms for quality assessment of CABG grafts.

Background: We have employed a conservative management approach, including intensive control of both blood pressure and heart rate, in patients with aortic intramural hematoma (AIMH) and retrograde thrombosed type A acute aortic dissection (RT-TAAAD), sharing common clinical and imaging characteristics. Methods: To evaluate the outcomes of our conservative management approach, we retrospectively reviewed the clinical records of 98 patients diagnosed with AIMH or RT-TAAAD from January 2008 to March 2023. A conservative management approach was applied, except for those patients with an aortic diameter ≥ 55 mm, false lumen expansion, or cardiac tamponade, who underwent emergency aortic repair. Results: Besides 2 patients, who declined surgery and subsequently died from aortic rupture, 18 patients underwent urgent aortic surgery, while 78 did not. Multivariable logistic regression analysis identified the extrusion type of ulcer-like projections (ULPs) on admission and a maximum aortic diameter ≥ 45 mm on Day 1 as risk factors for acute aortic surgery. Among the 78 patients who were discharged, 9 (12%) underwent aortic surgery, while 69 (88%) did not, with a median follow-up of 44 months. The overall actuarial aortic surgery-free rates were 78% at 1 year and 72% at 5 years, respectively. A Cox proportional hazards analysis identified ULPs and an aortic diameter ≥ 45 mm at discharge as risk factors for late aortic surgery. Conclusions: The early and late outcomes of our conservative strategy for AIMH and RT-TAAAD demonstrate favorable surgery-free rates. The extrusion type of ULPs on admission and an aortic diameter ≥ 45 mm on Day 1 are predictors of acute aortic surgery, while ULPs and an aortic diameter ≥ 45 mm at discharge are predictors of late surgery.

BACKGROUND: Infective endocarditis (IE) is a rare cardiovascular complication in patients with coronavirus disease 2019 (COVID-19). IE after COVID-19 can also be complicated by acute respiratory distress syndrome (ARDS); however, the guidelines for the treatment of such cases are not clear. Here, we report a case of perioperative management of post-COVID-19 IE with ARDS using veno-venous extracorporeal membrane oxygenation (V-V ECMO). CASE PRESENTATION: The patient was a 40-year-old woman who was admitted on day 18 of COVID-19 onset and was administered oxygen therapy, remdesivir, and dexamethasone. The patient's condition improved; however, on day 24 of hospitalization, the patient developed hypoxemia and was admitted to the intensive care unit (ICU) due to respiratory failure. Blood culture revealed Corynebacterium striatum, and transesophageal echocardiography revealed vegetation on the aortic and mitral valves. Valve destruction was mild, and the cause of respiratory failure was thought to be ARDS. Despite continued antimicrobial therapy, ARDS did not improve the patient's condition, and valve destruction progressed; therefore, surgical treatment was scheduled on day 13 of ICU admission. After preoperative consultation with the team, a decision was made to initiate V-V ECMO after the patient was weaned from CPB, with concerns about further worsening of her respiratory status after surgery. The patient returned to the ICU with transition to V-V ECMO, and her circulation remained stable. The patient was weaned off V-V ECMO on postoperative day 33 and discharged from the ICU on postoperative day 47. CONCLUSIONS: ARDS may occur in patients with IE after COVID-19. Owing to concerns about further exacerbation of pulmonary damage, the timing of surgery should be comprehensively considered. Preoperatively, clinicians should discuss perioperative ECMO introduction and configuration.

BACKGROUNDS:  One of the strategies to prevent stroke after coronary artery bypass grafting (CABG) may be the use of a device for proximal anastomosis without partial clamp of the ascending aorta. METHODS:  We retrospectively investigated early and late outcomes in consecutive 881 patients undergoing isolated CABG using Heartstring for proximal anastomosis from January 2008 to December 2022, to reveal the validity to use it. All patients underwent preoperative imaging workups to evaluate neurovascular atherosclerosis. RESULTS:  The mean age of the patients was 68.9 years, 20% were female and 13% had previous history of stroke. CABG was on-pump beating heart (52.2%) or off-pump (47.8%) with a mean number of distal anastomoses of 3.38 ± 0.93, using 1.62 ± 0.53 Heartstring devices under different aortic manipulations. In-hospital mortality was 2.0% and perioperative stroke rate was 0.9%, none of them died during hospital stay. During the follow-up period of 70 ± 47 months, the overall actuarial survival rates were 86 and 66%, and major adverse cardiac and cerebrovascular events (MACCEs)-free rates were 86 and 70% at 5 and 10 years, respectively. On multivariable analysis, risk factors for late death included male, previous history of stroke, postoperative sternomediastinitis, late new-onset stroke, and MACCEs, but did not include the perioperative stroke. CONCLUSION:  Low stroke rate, as low as 0.9%, after CABG using Heartstring for proximal anastomosis, although under a variety of aortic manipulations, may contribute to the improved long-term prognosis.

Abstract Background Although coronary artery bypass grafting (CABG) is performed via three different techniques, conventional, on-pump beating heart CABG (ONBHCAB), or off-pump CABG (OPCAB), data are limited to compare ONBHCAB with OPCAB. Methods We retrospectively investigated the postoperative cardiac biomarkers, creatine kinase-MB (CK-MB), and troponin I (cTnI), and early and late outcomes in 806 patients undergoing isolated ONBHCAB or OPCAB between February 2008 and September 2022. To eliminate the bias between different groups, propensity score matching was conducted to validate the findings. Results After matching, the number of each study group totaled 270 patients. In both complete and matched cohorts, early outcomes, including morbidities and mortalities, were similar. However, cTnI and CK-MB levels were significantly higher after ONBHCAB than after OPCAB with median peak cTnI of 9.85 versus 4.60 ng/mL and median peak CK-MB of 48.45 versus 17.10 ng/mL in the matched cohort, which were quite low, below the threshold for values defining perioperative myocardial infarction. At follow-up of 73 ± 45 months, the overall actuarial survival rates were similar between the ONBHCAB and OPCAB patients (86 vs. 87% at 5 years and 64 vs. 68% at 10 years, respectively, in the matched cohort). Conclusion ONBHCAB may be a comparable alternative to OPCAB with similar early and late outcomes, despite higher elevation of postoperative cardiac biomarkers. ONBHCAB provides more efficient hemodynamic support, providing a better surgical visual field, than OPCAB while reducing the risk of incomplete revascularization.