Pre-operative anaemia-does it influence post-operative outcomes after isolated coronary artery bypass grafting?

Introduction: Preoperative anaemia is prevalent in a number of patients undergoing coronary artery bypass grafting. Studies provide conflicting results due to several reasons including variation in the threshold of haematocrit used to define anaemia. We aimed to assess the independent effect of preoperative anaemia on outcomes in patients undergoing off pump coronary artery bypass grafting (OPCAB). Methods: In this retrospective study, patients with a hemoglobin level less than 11g/dl (haematocrit <33%) were considered to have moderate-to-severe anaemia as per the recommendations of the World Health Organization. Association between haematocrit <33% and mortality as well as adverse post-operative outcomes was assessed. Multivariable logistic regression (MLR) was carried out to assess the independent effect of haematocrit<33% on 30-day mortality and other outcomes. Results: The study included 4957 consecutive patients undergoing isolated OPCAB surgery between 2015 and 2020. Out of 4957, 635 (12.8%) had haematocrit <33% and 4322 (81.2%) had haematocrit ≥33%. Patients with haematocrit < 33% had a 30-day mortality of 13 (2%) compared to 38 (0.9%) in patients without anaemia and had a greater requirement for blood transfusion (p<0.0001). It was also associated with an increased incidence of renal failure (p<0.0001), tracheostomy (p=.0.012) and risk of re-intubation (p=0.006). On multiple linear regression (MLR), haematocrit < 33% was not an independent predictor of 30-day mortality odds ratio (OR) 1.47, 95% confidence interval (CI) 0.745-2.917; p=0.26. It was however an important independent risk factor for blood transfusion (OR 1.80, 95% CI 1.29-2.50, p<0.001) and renal failure (OR 3.06, 95% CI 1.338-7.012, p=0.008). The receiver operating characteristic (ROC)-area under the curve (AUC) was 0.63 suggesting moderate discriminatory value of haematocrit < 33% for 30-day mortality. Conclusion: Haematocrit < 33% is an important risk factor for adverse outcomes following isolated, primary, elective OPCAB. Supplementary Information: The online version contains supplementary material available at 10.1007/s12055-024-01746-1.

Impact of distension pressure on saphenous vein endothelial injury in coronary artery bypass grafting.

Introduction: Long saphenous vein grafts (LSVGs) are pivotal conduits in coronary artery bypass grafting (CABG), yet concerns persist regarding early failure and long-term patency. Endothelial damage, a potent initiator of graft failure, necessitates exploration of factors contributing to endothelial injury during LSVG preparation. Methods: A prospective, single-center study was conducted, assessing the impact of unregulated distension pressure on LSVG endothelium during CABG. Histological and CD31 (cluster of differentiation 31) immunohistochemical analyses were performed on 21 paired vein samples, categorized into non-distended (group A) and distended (group B) groups. Pressure recordings were obtained using different syringe sizes during vein distension. Results: Histological examination revealed a significantly higher percentage of endothelial cell loss in distended veins (31.95% ± 31.31) compared to non-distended veins (11.67% ± 28.65) (p = 0.034). CD31 immunohistochemistry corroborated greater endothelial cell loss in distended veins (p = 0.001). The pressure recordings with a 20-cc syringe, as opposed to using a 10-cc syringe, were considerably lower (44.5 mmHg vs. 92.75 mmHg) emphasizing the inverse relationship between syringe size and pressure generated. In our study, pre-existing endothelial injury was observed in one-third of diabetic patients (36%), with all instances of such injury exclusively identified in individuals with diabetes. Conclusion: Unregulated distension pressure during LSVG preparation is associated with greater endothelial damage, as evidenced by histological and immunohistochemical analyses. The inverse relationship between syringe size and pressure underscores the importance of controlled distension.

Cardiac magnetic resonance imaging for myocardial viability assessment: Optimizing surgical revascularization in ischemic heart disease.

BACKGROUND: Patients with poor ejection fraction undergoing coronary artery bypass grafting carry higher operative risk and have poor long-term survival. Cardiac magnetic resonance is a useful modality to assess viability which can identify patients likely to benefit most from revascularization. In this study, we aimed to assess the outcome in patients selected for surgical revascularization by cardiac magnetic resonance imaging and identify predictors associated with poor outcomes. METHODS: The study included patients with severely impaired left ventricular function but with at least six viable segments. Patients requiring emergency surgery, undergoing combined procedures, or where cardiopulmonary bypass was required were excluded. Cardiac magnetic resonance was carried out both preoperatively and at six months postoperatively by the same radiologist in all cases. Late gadolinium enhancement was used for the evaluation of myocardial viability. RESULTS: Amongst a total of 493 segments studied, there were 89 (18.1%) non-viable, 117 (23.7%) hibernating and 287 (58.2%) viable segments. At six months, the number of non-viable segments changed from 89 (18.1%) to 97 (19.7%), with an increase in viable segments from 287 (58.2%) to 374 (75.8%) and a corresponding reduction of hibernating segments from 117 (23.7%) to 22 (4.5%). There was improvement in ejection fraction from 28 ± 5.54 to 37 ± 5.86 (p < 0.0001) in the entire cohort at six months. Overall mortality was 1 (3.2%). Preoperative left ventricular end-systolic volume had the strongest negative correlation with post-operative ejection fraction. CONCLUSION: Cardiac magnetic resonance aided revascularization is associated with low mortality. Preoperative left ventricular end-systolic volume is an important determinant of postoperative ejection fraction.

Total arterial revascularization in a case of dextrocardia with situs inversus.

Dextrocardia and situs inversus with coronary artery disease poses unique challenges with respect to presentation and diagnosis. From a surgical point of view, the main decision-making revolves around the strategy of revascularization: the choice of right internal thoracic artery or the left internal thoracic artery for the left anterior descending artery anastomosis, the operating surgeon standing on the left or the right side of the operating table, and the choice of arterial or venous conduits. We report a case of total arterial revascularization using off pump coronary artery bypass technique in a case of dextrocardia with situs inversus using We discuss the various challenges involved in the diagnosis and management.

Renal Function Improvement after Aortic Valve Replacement in a Patient with Chronic Kidney Disease - A Case Report.

Inadequate peripheral perfusion due to cardiac diseases can worsen renal function in patients with chronic kidney disease (CKD). Due to the nature of the simultaneous cardiac and renal disease, it is often difficult to determine which is the primary cause, and hence many surgeons hesitate to operate on patients with end-stage kidney disease. However, when the primary cause is cardiac related, renal function can improve after successful cardiac surgery. Here, we describe a 55-year-old female patient with CKD Stage 5 who was on maintenance hemodialysis with severe aortic stenosis (AS) and underwent surgical aortic valve replacement and recovered from dialysis-dependent kidney disease. Drastic improvement in renal function after cardiac surgery can occur even in patients with CKD due to improved renal perfusion, especially in cases of AS. Therefore, diagnosing the primary cause of renal dysfunction is essential.