Impact of off-pump coronary artery bypass grafting on survival: current best available evidence

Outcomes of urgent coronary artery bypass grafting in patients who have recently recovered from COVID-19 infection, with a median follow-up period of twelve months: our experience

Background

The Coronavirus disease 2019 (COVID-19) was declared a worldwide pandemic in 2020 by the World Health Organization (WHO). Certain individuals are at higher risk, (age > 65 years, pre-existing lung or heart conditions, diabetes and obesity) especially those requiring cardiac surgery, including Coronary Artery Bypass Grafting (CABG). Here we present a case series of 11 patients, operated between April 2020 and April 2022, all of whom had recently recovered from COVID-19, who presented with unstable angina, and therefore required urgent Coronary Artery Bypass Grafting (CABG). Similar cases reported in the past, have had a high morbidity and mortality rate.

Case presentation

The study included 11 males, and their age varied between 53 and 68 years (median of 65 years). They were either partially or fully vaccinated. All of them had a history of recent mild COVID-19 infection. The European system for cardiac operative risk evaluation, EuroSCORE II in-hospital mortality risk at admission, varied between 1.48% and 5.12%. Six out of 11 patients (54.55%) had a recent Acute Coronary Syndrome (ACS) which is associated with a higher risk and poor prognosis. All of them underwent urgent CABG (10 of them, 90.91% cases, using the off-pump technique and one patient had to be converted to the on-pump beating heart surgery technique during surgery). Ten of the 11 patients were operated using the off-pump technique, and there was one death (9.09%). All surviving patients made an uneventful recovery and have been followed up with a median follow-up period of 12 months.

Conclusions

Previous studies on a similar group of patients have resulted in high morbidity and mortality. A conscious effort was made to perform all surgeries off-pump, thereby eliminating the inflammatory effects and other hazards of cardiopulmonary bypass in this case series, with only one out of 11 (9.09%) being converted to the on-pump beating heart technique due to the hemodynamic instability faced during surgery. Our findings show a mortality rate of 9.09%, with the surviving patients doing well at a median follow-up period of 12 months, suggesting that it is a safe procedure in this patient subset.

Postoperative Neutrophil to Lymphocyte Ratio as an Overall Mortality Midterm Prognostic Factor following OPCAB Procedures

BACKGROUND

Off-pump coronary artery bypass grafting (OPCAB) is believed to limit inflammatory reaction. Neutrophil to lymphocyte ratio (NLR) is one of the more common and easily accessible markers of inflammatory response. The aim of the study was to compare postoperative results of NLR with mid-term OPCAB results.

METHODS

In total, 224 patients (198 (88%) men and 26 (12%) women) with mean age 65 +/- 9 years who underwent OPCAB though median full sternotomy in our department in 2018 enrolled into the study. We scrupulously collected the postoperative mid-term results, including survival rate, clinical status and risk for major adverse events, and compared them with perioperative laboratory results.

RESULTS

A three-year follow-up was completed by 198 individuals (90% survival rate) with 12 (5%) showing major adverse cardiovascular (MACE) events risk. In the multivariable analysis, the laboratory parameters noticed on the 1st postoperative day were statistically significantly predictive of survival, including neutrophils (HR 1.59, 1.33-1.89 95%CI, p < 0.0001), platelets (HR 1.01, 1.01-1.01 95%CI, p = 0.0065), NLR (HR 1.47, 1.3-1.65 95%CI, p < 0.0001) and postoperative ejection fraction (HR 0.9, 0.87-0.95 95%CI, p < 0.0001).

CONCLUSIONS

Postoperative NLR above 4.6, as an inflammatory reaction marker, is related to mid-term mortality in OPCAB patients.

Cardiac Surgery: Beyond Conventional Sternotomy With Cardiopulmonary Bypass

Minimally invasive cardiac surgery options, which originated with off-pump coronary artery bypass grafting and aortic valve procedures, continue to evolve in order to address complex conditions, including those requiring mitral and tricuspid valve repair. Although these procedures are primarily indicated for high-risk patient populations, favorable patient outcomes have resulted in recommendations being expanded to include intermediate-risk groups. This article increases nursing-related knowledge of minimally invasive cardiac procedures, providing an overview of current minimally invasive cardiac surgeries and their associated risks and benefits.

Comparison between creatine kinase MB, heart-type fatty acid-binding protein, and cardiac troponin T for detecting myocardial ischemic injury after cardiac surgery

BACKGROUND

Heart-type fatty acid-binding protein (H-FABP) is a cytoplasmic protein and is released form necrotic cardiac myocytes, as well as ischemic cardiac myocytes. In this study, we compared creatine kinase MB (CK-MB), H-FABP, and cardiac troponin T (cTnT) after coronary artery bypass grafting (CABG), heart valve surgery, or septal defect surgery to evaluate the difference in detecting myocardial injury between three markers.

METHODS

A total of 69 patients (CABG, 32; valve surgery, 27; and septal defect surgery, 10) were prospectively enrolled. Blood samples were taken at specific intervals.

RESULTS

Mean amount (AUC_0-72h) of CK-MB and cTnT released for 72 h in the patients with valve surgery were 2446 h·ng/ml and 93.2 h·ng/ml, which were significantly larger than those in the patients with CABG or septal defect surgery (p < .05). Mean amount (AUC_0-72h) of H-FABP released for 72 h in the patients with CABG was 1939 h·ng/ml, which was significantly larger than that in the patients with septal defect surgery (700.1 h·ng/ml) (p < .05).

CONCLUSION

H-FABP would be a more useful marker for detecting myocardial ischemic injury than CK-MB and cTnT. CK-MB and cTnT would be more sensitive to myocardial injury with surgical trauma than with ischemic injury in the patients with cardiac surgery.

Observation of local cardiac electrophysiological changes during off-pump coronary artery bypass grafting using epicardial mapping

OBJECTIVES

At present, there is no effective method of evaluating the electrophysiological changes in cardiac myocytes during off-pump coronary artery bypass grafting (OPCAB). Therefore, we preliminarily explored the relationship between electrophysiological characteristics and the changes in cardiac function of 24 patients undergoing OPCAB.

METHODS

We used the CARTO3 system for epicardial electrophysiological mapping before surgery, during left anterior descending branch anastomosis, diagonal branch anastomosis and after surgery for 24 patients undergoing OPCAB. Data, including local activation time (LAT), bipolar voltage value (BV) and conduction velocity, were processed and analyzed by the system. Intraoperative invasive blood pressure, heart rate and arterial blood gas analysis data were recorded. Continuous electrocardiography (ECG) monitoring was performed three days after surgery. Routine resting myocardial perfusion imaging (MPI) and adenosine stress-gated MPI were performed before surgery. Patients were re-examined before discharge.

RESULTS

By analyzing the change in the LAT value, we found that the order of excitation of local myocardial cells changed after surgery. In addition, the LAT change in myocardial cells closer to the anastomosis was more significant. The earliest pacing point on the left anterior descending (LAD) coronary artery territory map was the third point (from the proximal to distal LAD) before OPCAB, but the earliest pacing point moved down to the fourth point (closer to the anastomosis) after the diagonal (DIA) anastomosis was complete. On the DIA territory map, the earliest pacing point was the fourth point before OPCAB; this moved up to the third point (closer to the anastomosis) after DIA bypass grafting. The voltages of all points were increased after myocardial revascularization. Compared with the preoperative period, the third, fourth and fifth points on the LAD territory map increased significantly after LAD anastomosis was complete (p=0.007, p=0.001, p=0.009, respectively). On the DIA territory map, the voltages of the first, second and third points were remarkably increased after completing the DIA anastomosis compared to before OPCAB and after LAD anastomosis completion (p=0.001, p=0.008, p<0.001 and p=0.006, p=0.032, p=0.002, respectively). The average conduction velocity (ACV) of all mapped points increased after OPCAB compared with before OPCAB (p<0.05). Postoperative resting MPI and adenosine stress-gated MPI showed that left ventricular global systolic function improved, the left ventricular ejection fraction (LVEF) increased significantly (p<0.05) and the left ventricular end systolic volume (LVESV) decreased significantly (p<0.05) compared to the preoperative MPI.

CONCLUSIONS

Adequate surgical coronary revascularization could lead to more stable electrical activity of local cardiomyocytes, thus, illustrating the specific mechanism of coronary revascularization for improving the cardiac function from an electrophysiological perspective.