Transfusion of red blood cells (RBC) and other blood products in patients undergoing coronary artery bypass grafting (CABG) is associated with increased mortality and morbidity. We retrospectively analyzed data of patients who underwent an isolated coronary bypass graft operation between January 1998 and December 2007. Mean follow-up was 1696+/-1026 days, with exclusion of 122 patients lost to follow-up and 80 patients who received 10 units of RBC. Of the remaining patients, 8001 (76.7%) received no RBC, 1621 (15.2%) received 1-2 units of RBC, 593 (5.7%) received 3-5 units and 220 (2.1%) received 6-10 units. The number of transfused RBC was a predictor for early but not for late mortality. When compared to expected survival, survival of patients not receiving any blood product was better, while survival of patients receiving >3 units of RBC was worse. Transfusion of RBC is an independent, dose-dependent risk factor for early mortality after revascularization. Compared to expected survival, receiving no RBC improves patient long-term survival, whereas receiving three or more units of RBC significantly decreases patient survival.

Laboratory and clinical data have implicated endotoxin as an important factor in the inflammatory response to cardiopulmonary bypass. Alkaline phosphatase prevents endotoxin-induced systemic inflammation in animals and humans. We assessed the effects of the administration of bovine intestinal alkaline phosphatase on surgical complications in patients undergoing coronary artery bypass grafting. In a double blind, randomized, placebo-controlled study, a total of 63 patients undergoing coronary artery bypass grafting were enrolled. Bovine intestinal alkaline phosphatase or placebo was administered as an intravenous bolus followed by continuous infusion for 36 hours. The primary endpoint was reduction of post-surgical inflammation. No significant safety concerns were identified. The overall inflammatory response to coronary artery bypass grafting with cardiopulmonary bypass was low in both placebo and bovine intestinal alkaline phosphatase patient group. Five patients in the placebo group displayed a significant TNFalpha response followed by an increase in plasma levels of IL-6 and IL-8. Such a TNFalpha response was not observed in the bovine intestinal alkaline phosphatase group, suggesting anti-inflammatory activity of bovine intestinal alkaline phosphatase. Other variables related to systemic inflammation showed no statistically significant differences. Bovine intestinal alkaline phosphatase can be administered safely in an attempt to reduce the inflammatory response in coronary artery bypass grafting patients with a low to intermediate EuroSCORE. The anti-inflammatory effects might be more pronounced in patients developing more fulminant postoperative inflammatory responses. This will be investigated in a further trial with inclusion of patients undergoing complicated cardiac surgery, demanding extended cardiopulmonary bypass and aortic cross clamp time. In this review article some recent patents related to the field are also discussed.

Background: Approximately 15% of saphenous vein grafts (SVGs) occlude during the first year after coronary artery bypass graft surgery (CABG) despite aspirin use. The POPular CABG trial investigated whether ticagrelor added to standard aspirin improves SVG patency at one year after CABG. Methods: In this investigator-initiated, randomized, double-blind, placebo-controlled, multicenter trial, patients with ≥1 SVGs were randomly assigned (1:1) after CABG to ticagrelor or placebo added to standard aspirin (80mg or 100mg). The primary outcome was SVG occlusion at one year, assessed with coronary computed tomography angiography, in all patients that had primary outcome imaging available. A generalized estimating equation model was used to perform the primary analysis per SVG. The secondary outcome was one-year SVG failure, which was a composite of SVG occlusion, SVG revascularization, myocardial infarction in myocardial territory supplied by a SVG or sudden death. Results: Among 499 randomized patients, the mean age was 67.9±8.3 years, 87.1% were male, the indication for CABG was Acute Coronary Syndrome in 31.3%, and 95.2% of procedures used cardiopulmonary bypass. Primary outcome imaging was available in 220 patients in the ticagrelor group and 223 patients in the placebo group. The SVG occlusion rate in the ticagrelor group was 10.5% (51 of 484 SVGs) versus 9.1% in the placebo group (43 of 470 SVGs), OR 1.29 [95% CI: 0.73 -2.30]; P =0.38. SVG failure occurred in 35 (14.2%) patients in the ticagrelor group versus 29 (11.6%) patients in the placebo group (OR 1.22, [95% CI: 0.72-2.05]). Conclusions: In this randomized, placebo-controlled trial, the addition of ticagrelor to standard aspirin did not reduce SVG occlusion at one year after CABG. Clinical Trial Registration: URL: https://clinicaltrials.gov; Unique Identifier: NCT02352402.

Summary Despite there being numerous studies of intraoperative graft flow assessment by transit-time flow measurement (TTFM) on outcomes after coronary artery bypass grafting (CABG), the adoption of contemporary TTFM is low. Therefore, on 31 January 2018, a systematic literature search was performed to identify articles that reported (i) the amount of grafts classified as abnormal or which were revised or (ii) an association between TTFM and outcomes during follow-up. Random-effects models were used to create pooled estimates with 95% confidence intervals (CI) of (i) the rate of graft revision per patient, (ii) the rate of graft revision per graft and (iii) the rate of graft revision among grafts deemed abnormal based on TTFM parameters. The search yielded 242 articles, and 66 original articles were included in the systematic review. Of those articles, 35 studies reported on abnormal grafts or graft revisions (8943 patients, 15 673 grafts) and were included in the meta-analysis. In 4.3% of patients (95% CI 3.3–5.7%, I2 = 73.9) a revision was required and 2.0% of grafts (95% CI 1.5–2.5%; I2 = 66.0) were revised. The pooled rate of graft revisions among abnormal grafts was 25.1% (95% CI 15.5–37.9%; I2 = 80.2). Studies reported sensitivity ranging from 0.250 to 0.457 and the specificity from 0.939 to 0.984. Reported negative predictive values ranged from 0.719 to 0.980 and reported positive predictive values ranged from 0.100 to 0.840. This systematic review and meta-analysis showed that TTFM could improve CABG procedures. However, due to heterogeneous data, drawing uniform conclusions appeared challenging. Future studies should focus on determining the optimal use of TTFM and assessing its diagnostic accuracy.