Off-pump coronary artery bypass grafting in India

Off-pump CABG surgery in left main coronary artery disease: a single-center prospective registry

Background and objective

The treatment of left main (LM) coronary artery disease (CAD) requires complex decision-making. Patients with left main multi-vessel coronary artery disease (LM CAD) have concerns regarding incomplete revascularization and reduced survival with off-pump (OPCAB) when compared with on-pump (ONCAB) coronary bypass surgery. To evaluate outcomes among high-risk LM CAD patients undergoing OPCAB, we performed a registry-based prospective study.

Methods

We performed 4868 coronary artery bypass graft (CABG) surgeries from Jan 2013 to Jun 2019 with 4662 (95.8%) OPCAB. In OPCAB cohort, we had 1323 patients (28.4%) with significant LM (> 50%) triple vessel CAD. Data regarding clinical features, extent of CAD, operative details, in-hospital outcomes, and 3-year follow-up were obtained. Descriptive statistics are reported.

Results

The study cohort (n = 1323) was aged 63 ± 9 years with men 88.4%. Tobacco use was in 328 (24.8%), diabetes 598 (45.2%), previous myocardial infarction 463 (35.0%), previous coronary intervention 40 (3.0%), and congestive heart failure in 54 (4.1%). All patients had LM (100.0%) with triple vessel disease in 99.4% (LAD, left anterior descending 100.0%; LCX, left circumflex 99.4%; RCA, right coronary artery 78.7%). Vessels bypassed/patient were 2.7 ± 0.4 with 3.2 ± 0.7 total grafts and 2.1 ± 0.8 venous grafts. In total, 1278 (96.5%) patients received left internal mammary artery (LIMA), 63(4.7%) bilateral internal mammary artery (BIMA), and 74 (5.6%) radial artery grafts. There was no patient with conversion from OPCAB to ONCAB. In-hospital major adverse cardiovascular events (MACE: all-cause deaths, myocardial infarction, and stroke) were in 21 (1.6%). At 3-year follow-up (n = 1041), MACE rates were in 84 (8.1%) and cardiovascular deaths in 28 (2.7%).

Conclusions

This study shows that off-pump CABG surgery is safe in patients with LM CAD. There is low in-hospital mortality and MACE and 3-year outcomes are similar to the published data of LM CAD patients who undergo on-pump CABG.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-023-01526-3.

Comprehensive Study of Different Expressed Genes and Their Functional Modules in Anesthesia for Off-Pump Coronary Artery Bypass Grafting

Purpose

The effect of preoperative anesthesia on coronary artery bypass grafting without extracorporeal circulation is not apparent. We want to investigate the effects and molecular mechanisms of two anesthesia methods on the treatment of coronary artery bypass grafting (OPCABG) under extracorporeal circulation. Patients and Methods. The data of inhaled anesthesia and intravenous anesthesia before coronary artery bypass grafting were downloaded from the GEO database, and the differences were analyzed with the control group. The combination of multiple analytical methods can decipher the mechanism of anesthesia on surgery, including protein interaction network analysis, enrichment analysis, and regulatory subprediction.

Results

This study obtained 6699 differential genes under two kinds of anesthesia before OPCABG. By constructing a protein interaction network of differentially expressed genes, we obtained 14 functional module networks. By predicting regulators of functional module genes, we revealed a series of ncRNAs (miR-129-5p, miR-340-5p, and miR-410-3p) and transcription factors (VHL and YBX1).

Conclusion

Based on functional module network analysis, we identified the effects of preoperative inhalation anesthesia and intravenous anesthesia on OPCABG, which provides a valuable theoretical reference for subsequent clinical studies.

Is magnesium sulfate friend or foe of off-pump coronary artery bypass surgery?

Magnesium sulfate is often used empirically in cardiac surgical settings. Magnesium sulfate may cause platelet dysfunction leading to bleeding complication. This editorial commentary discusses the published study of intra-operative use of magnesium sulfate during off-pump coronary artery bypass grafting published in this issue of Indian Heart Journal.

Preoperative intra-aortic balloon pump improves the clinical outcomes of off-pump coronary artery bypass grafting in left ventricular dysfunction patients

Severe left ventricular (LV) dysfunction patients undergoing off-pump coronary artery bypass grafting (OPCAB) are often associated with a higher mortality. The efficacy and safety of the preoperative prophylactic intra-aortic balloon pump (IABP) insertion is not well established. 416 consecutive patients with severe LV dysfunction (ejection fraction ≤35%) undergoing isolated OPCAB were enrolled in a retrospective observational study. 191 patients was enrolled in the IABP group; the remaining 225 patients was in control group. A total of 129 pairs of patients were propensity-score matched. No significant differences in demographic and preoperative risk factors were found between the two groups. The postoperative 30-day mortality occurred more frequently in the control group compared with the IABP group (8.5% vs. 1.6%, p = 0.02). There was a significant reduction of low cardiac output syndrome in the IABP group compared with the control group (14% vs. 6.2%, p = 0.04). Prolonged mechanical ventilation (≥48 h) occurred more frequently in the control group (34.9% vs. 20.9%, p = 0.02). IABP also decreased the postoperative length of stay. Preoperative IABP was associated with a lower 30-day mortality, suggesting that it is effective in patients with severe LV dysfunction undergoing OPCAB.

Off-pump coronary artery bypass grafting using continuous heparin infusion

Objectives

Levels of anticoagulation during off-pump coronary artery bypass grafting (OPCAB) remain controversial. Prolonged activated clotting time (ACT) during OPCAB increases blood loss during surgery and can also cause paradoxical increase in postoperative myocardial infarction. Shorter ACT can increase thrombotic complication. Maintaining a steady ACT level is challenging. We have used continuous heparin infusion after initial bolus during OPCAB to maintain a steady low target ACT. The objective of the present study was to assess the effectiveness and safety of heparin infusion in maintaining a steady target ACT level.

Methods

This was a prospective study of consecutive OPCAB patients. ACT was measured after initial bolus dose of heparin. Once ACT of more than 200 seconds was achieved, heparin infusion was started to maintain the required level of anticoagulation. CPK-MB was measured in operation room, 6 and 24 hours postoperatively to rule out ischemic complication.

Results

ACT could be maintained in target range with heparin infusion in 80.1% patients (161/201). Of the 40 patients with one or more ACT reading less than 200 seconds, 38 patients were managed by increasing the dose of heparin infusion and only 2 patients required additional bolus dose of heparin.

Conclusions

Heparin infusion maintains a steady target ACT level and avoids peaks and troughs associated with bolus doses. Lower level of anticoagulation using continuous heparin infusion does not increase ischemic complications. This is the first ever study of use of heparin infusion during OPCAB. We may conclude that heparin infusion is a safe anticoagulation strategy for OPCAB.

Depression and Anxiety following Coronary Artery Bypass Graft: Current Indian Scenario

Epidemiological studies have shown a high prevalence of coronary artery disease among the Indian Population. Due to increasing availability and affordability of tertiary care in many parts of India, carefully selected patients undergo coronary artery bypass surgery to improve cardiac function. However, the procedure is commonly associated with depression and anxiety which can adversely affect overall prognosis. The objective of this review is to highlight early identifiable symptoms of depression and anxiety following coronary artery bypass graft (CABG) in Indian context so as to facilitate prompt intervention for better outcome. The current review was able to establish firm evidence in support of screening for depression and anxiety following CABG. Management of depression and anxiety following CABG is briefly reviewed.

Nicorandil Infusion During Off-Pump Coronary Artery Bypass Grafting Reduces Incidence of Intra-aortic Balloon Pump Insertion

OBJECTIVE

Off-pump coronary artery bypass grafting in patients with left ventricular dysfunction has proven to be advantageous. However, it carries risk of emergency conversion to cardiopulmonary bypass. We have successfully used an intra-aortic balloon pump to prevent such conversion. The objective of the present study was to evaluate if intravenous nicorandil infusion reduces the incidence of intraoperative intra-aortic balloon pump insertion.

METHODS

Consecutive cases of isolated off-pump coronary artery bypass surgery performed by a single surgeon were studied. Patients were divided into two groups. The first group did not receive nicorandil, and the second group received intraoperative nicorandil infusion (started in the operating room after central line insertion).

RESULTS

A total of 375 patients were included in the study. Four patients in the non-nicorandil group and the patients in nicorandil group were on preoperative intra-aortic balloon pump and hence excluded from the study. After routine use of nicorandil infusion, incidence of intra-aortic balloon pump insertion during off-pump coronary artery bypass surgery decreased from 12.4% (21/169) to 2.9% (6/206).

CONCLUSIONS

Nicorandil infusion significantly (P = 0.007) reduced the incidence of intra-aortic balloon pump insertion in our series. In patients with left ventricular dysfunction (ejection fraction ≤ 30%), this difference (P = 0.008) assumes a special significance as off-pump bypass surgery is considered high risk in this subset. Nicorandil is an inexpensive drug, and the reduction in cost of surgery by avoiding intra-aortic balloon pump insertion is an added advantage. The use of nicorandil infusion during off-pump coronary artery bypass may result in favorable patient outcomes by reducing invasive intra-aortic balloon pump insertion during off-pump coronary artery bypass grafting.

Total arterial anaortic off-pump coronary artery bypass grafting for diffuse coronary disease - A case report

Surgical treatment of diffuse coronary artery disease remains challenging. We present here a diabetic patient, with diffuse coronary disease, revascularized using total arterial anaortic off-pump coronary artery bypass grafting. He received total nine distal grafts. He continues to be asymptomatic after more than 2 years. CT angiography follow-up shows eight out of nine grafts are patent. Anaortic off-pump coronary artery bypass grafting has the least incidence of stroke and arterial grafts have the best long-term patency rate. This is the first case report of nine arterial bypass graft performed off-pump using both internal mammary and both radial arteries. Anaortic total arterial off-pump coronary artery bypass grafting has achieved excellent intermediate term result in this patient of diffuse coronary artery disease.

Off-pump Bilateral Internal Thoracic Artery Grafting

BACKGROUND

The long-term benefit of bilateral internal thoracic grafts (BITA) is well established. BITA grafting is often avoided in diabetic, female, obese, elderly and other high-risk patients because of concerns for deep sternal wound infection. The objective of this study is to analyse early results of our BITA grafting and to establish the safety of BITA use in all patients.

METHODS

All cases of isolated consecutive unselected CABG were included in this retrospective study. BITA were used in-situ - one was used to graft left anterior descending artery and the other was used as inflow for a composite graft with radial artery. Dual inflow using in situ BITA grafting allows easy bailout by using an additional vein graft.

RESULTS

BITA was used in 574 patients out of 602 (95.35%). Incidence of early death was 1.33% (8/602), stroke 0.5% (3/602), reoperation for bleeding 0.17% (1/602). Deep sternal wound infection was not seen in any patient but nine patients (1.5%) had superficial wound infection which healed with dressing.

CONCLUSION

We have used BITA in 95% of our unselected, consecutive off-pump CABG patients without any major wound complications. Our limited experience has shown off-pump CABG using BITA grafting can be safely adopted routinely with excellent early result.