Complete Heparin Reversal by Protamine during Off-Pump Coronary Artery Bypass Surgery (OPCAB): A Necessity or Myth?

In our country majority of the coronary artery bypass surgery (CABG) are done off-pump and was reported having excellent clinical outcome along with cost efficiency by various investigators. Heparin is commonly used as most effective anticoagulant, and protamine sulfate is now generally used to reverse the anticoagulant action of heparin. While under dosing of protamine may result in incomplete heparin reversal and prolonged anticoagulation, protamine overdosing is associated with impaired clot formation exerted by the intrinsic anti-coagulation properties of protamine itself, moreover protamine administration is associated with mild to severe cardiovascular and pulmonary complications. Apart from traditional full neutralization of heparin now-a-days, half dose protamine was also introduced showing good outcome regarding lower activated clotting time (ACT), overall, less surgical bleeding with less transfusion. This comparative study was designed to detect differences between traditional and decreased protamine dosing in Off-Pump Coronary Artery Bypass (OPCAB) surgery. Four hundred (400) patients who underwent Off-Pump Coronary Artery Bypass Surgery (OPCAB) surgery at our institution over a period of 12 months were analyzed and were divided into two groups. Group A- received 0.5mg of protamine per 100 unit of heparin; Group B-received 1.0mg of protamine per 100 unit of heparin. ACT, blood loss, hemoglobin and platelet count units of blood and blood product transfusion requirements, clinical outcome and hospital stay were assessed in each patient. This study showed that 0.5mg of protamine per 100 unit of heparin was always able to reverse the anticoagulant effect of heparin with no significant difference in hemodynamic parameters, amount of blood loss and requirements of blood transfusion in between the groups. A standard protamine dosing formula (protamine-heparin at ratio of 1:1) adequate for on-pump cardiac surgical procedures significantly overestimates protamine requirements for OPCAB. Patients treated with decreased protamine do not appear to have adverse outcomes in terms of post-operative bleeding.

Coronary Artery Revascularization with the Left Internal Mammary Artery (LIMA) to Diagonal (D) & Left Anterior Descending (LAD) Sequential and LIMA-LIMA "Y" Graft, Our Experiences at National Heart Foundation Hospital and Research Institute.

The Left internal mammary artery (LIMA) is considered the conduit of choice for the surgical treatment (CABG, coronary artery bypass grafting) of Coronary artery disease (CAD) due to its superior long term potency than the other conduits. Sequential anastomosis with the LIMA in CABG increases the number of arterial graft and more completeness the arterial revascularization. To increase the number of arterial graft and improved long term potency, an alternative technique is sequential anastomosis of LIMA to Diagonal (D) & left anterior descending artery (LAD) and LIMA-LIMA "Y" Graft play a vital role in patients with tight proximal lesion. Perioperative data were prospectively collected from all patients with isolated CAD with tight proximal LAD lesion, who underwent off-pump CABG from November 2013 to October 2015 at a single Centre. A total of 321 patients had LIMA to D & LAD sequential and LIMA-LIMA "Y" grafts pattern with severe proximal LAD lesion. The mean age was 54.7±8.4 years, male & female ratio was 29.7:7.5. Left main involvement was in 25% & triple vessel disease was 89% with LVEF 53.6±8.6%. Sequential LIMA to diagonal (side to side) & LAD (end to side) done in all 294 cases and LIMA-LIMA"Y" grafts in 27 cases. Thirty days mortality was 0.935% (3 patients). Postoperative myocardial infarction (MI) occurred in 2 patients (0.623%). Two sequential LIMA graft failed and both the diagonal & LAD bypassed coronary arteries were very narrow, about 1mm in diameter. All the patients underwent postoperative NYHA class evaluation at 3-6 months follow up & found normal and none of the patients suffered for angina. Revascularization with skeletonized sequential LIMA anastomosis to D, LAD & LIMA-LIMA "Y" graft is a safe, feasible with improve overall long-term potency and reproducible alternative in the presence of severe proximal LAD lesion to the complete revascularization of the anterior& lateral myocardial wall. Long term follow-up with coronary angiogram is essential to recommend this technique as standard one.

Significant Left Main Coronary Artery Disease Does Not Incur Any Additional Risk to the Short Term Outcome of Off Pump Coronary Artery Bypass Grafting Surgery.

Coronary artery disease is the most common form of heart disease and single most important cause of premature death in developed countries. Off pump coronary artery bypass grafting surgery has recently became widespread internationally and has produced good clinical outcome even in left main coronary artery disease following off pump coronary artery bypass grafting surgery. A prospective observational study was conducted in the department of Cardiac Surgery, National Heart Foundation Hospital and Research Institute, Dhaka, Bangladesh from January 2015 to September 2016 after fulfillment of enrollment criteria, 428 patients were studied for the purpose of the study and they were grouped in two, significant left main coronary artery disease in group A and non left main coronary artery disease requiring surgery in group B. Comparison of risk factors between groups demonstrates that diabetes mellitus and smoking habit between two groups were almost identical. 69.2% of patient with significant left main coronary artery group were hypertensive and 25.2% were dyslipidaemic in comparison to non left main coronary artery disease group which were 50.9% and 6.5% respectively. Requirement of per operative inotropic support was significantly higher in left main coronary artery group. 33.6% of patient of left main coronary artery group required per operative inotropic support whereas non left main coronary artery group require 24.8%. Postoperative inotropic support, mechanical ventilation time, ICU stay, hospital stay and complication were similar in both these groups. So, we can say that off pump coronary artery bypass grafting surgery for significant left main coronary artery disease is as safe as non left main coronary artery disease.