Single-territory incomplete surgical revascularization improves regional wall motion of remote ventricular areas: results from a propensity-matched study

Quantitative analysis of myocardial blood flow in surgically revascularized and not revascularized myocardial segments. A pilot PET study

PURPOSE

To prospectively compare changes in myocardial blood flow (MBF) and myocardial flow reserve (MFR) in multivessel coronary artery disease (MVCAD) patients undergoing incomplete revascularization (IR) versus complete revascularization (CR) by coronary artery bypass grafting (CABG).

METHODS

Seven male patients (age 68 ± 9 years) with MVCAD underwent myocardial perfusion PET/CT with [13N]ammonia before and at least 4 months after CABG. Segmental resting and stress MBF as well as MFR were measured. Resting and during stress left ventricle ejection fraction (LVEF) were also calculated.

RESULTS

Three patients (43%) underwent CR and four (57%) IR. Among 119 myocardial segments, 101 (85%) were revascularized, and 18 (15%) were not. After CABG, stress MBF (mL/min/gr) and MFR are significantly increased in all myocardial segments, with a greater increase in the revascularized segments (p = 0.013). In both groups, LVEF significantly decreased during stress at baseline PET (p = 0.04), but not after CABG.

CONCLUSION

Stress MBF and MFR significantly improve after CABG in both revascularized and not directly revascularized myocardial segments. IR strategy may be considered in patients with high surgical risk for CR.

Off-pump or on-pump coronary artery bypass at 30 days: A propensity matched analysis

Introduction

This study was to determine whether coronary artery bypass grafting without cardiopulmonary bypass (off-pump CABG, OPCAB) could reduce early postoperative mortality and major complications compared with conventional coronary artery bypass grafting with cardiopulmonary bypass (on-pump CABG, ONCAB) by experienced surgeons.

Material and methods

From January 2016 to June 2020, isolated CABG was performed in 1200 patients (ONCAB 429, OPCAB 771) in Wuhan Union Hospital. The propensity score matching was used to adjust for differences in baseline characteristics between the ONCABG and OPCABG groups. After 1:1 matching, 404 pairs for each group were selected to compare outcomes within 30 days after surgery. All the operations were completed by experienced surgeons that had completed more than 500 on-pump and 200 off-pump CABG, respectively.

Results

After propensity matching, the two groups were comparable in terms of preoperative characteristics. The OPCAB group had less vein graft (2.5 ± 1.0 vs. 2.7 ± 0.9; P < 0.001) and a higher rate of incomplete revascularization (12.4 vs. 8.2%; P < 0.049) than the ONCAB group. There was no significant difference in early postoperative mortality between ONCAB and OPCAB groups (2.2 vs. 2.2%; P = 1.00). However, patients in the OPCAB group had a lower risk of postoperative stroke (1.5 vs. 4.7%; P = 0.008), new-onset renal insufficiency (8.9 vs. 18.8%; P < 0.001), respiratory failure (2.2 vs. 7.2%; P = 0.001), reoperation for bleeding (0.5 vs. 2.7%; P = 0.001), and required less ventilator assistance time (33.4 ± 37.9 h vs. 51.0 ± 66.1 h; P < 0.001) and intensive care unit (ICU) time (3.7 ± 2.7 days vs. 4.8 ± 4.3 days; P < 0.001).

Conclusions

In our study, patients undergoing OPCAB had fewer postoperative complications and a faster recovery. It is a feasible and safe surgical approach to achieve revascularization when performed by experienced surgeons.

The Role of Angiogenesis and Arteriogenesisin Myocardial Infarction and Coronary Revascularization

Surgical myocardial revascularization is associated with long-term survival benefit in patients with multivessel coronary artery disease. However, the exact biological mechanisms underlying the clinical benefits of myocardial revascularization have not been elucidated yet. Angiogenesis and arteriogenesis biologically leading to vascular collateralization are considered one of the endogenous mechanisms to preserve myocardial viability during ischemia, and the presence of coronary collateralization has been regarded as one of the predictors of long-term survival in patients with coronary artery disease (CAD). Some experimental studies and indirect clinical evidence on chronic CAD confirmed an angiogenetic response induced by myocardial revascularization and suggested that revascularization procedures could constitute an angiogenetic trigger per se. In this review, the clinical and basic science evidence regarding arteriogenesis and angiogenesis in both CAD and coronary revascularization is analyzed with the aim to better elucidate their significance in the clinical arena and potential therapeutic use.

Ischemic Mitral Regurgitation: A Multifaceted Syndrome with Evolving Therapies

Dysfunction of the left ventricle (LV) with impaired contractility following chronic ischemia or acute myocardial infarction (AMI) is the main cause of ischemic mitral regurgitation (IMR), leading to moderate and moderate-to-severe mitral regurgitation (MR). The site of AMI exerts a specific influence determining different patterns of adverse LV remodeling. In general, inferior-posterior AMI is more frequently associated with regional structural changes than the anterolateral one, which is associated with global adverse LV remodeling, ultimately leading to different phenotypes of IMR. In this narrative review, starting from the aforementioned categorization, we proceed to describe current knowledge regarding surgical approaches in the management of IMR.