Transient time flow measurement in arterial grafts.

Coronary artery bypass grafting (CABG) is one of the foundations of treatment for coronary artery disease. While it has improved substantially since its inception more than 50 years ago, including a rising use of multiple arterial grafting, intraoperative quality assessment is yet to be disseminated as an integral part of the procedure. Herein we review the fundamentals of intraoperative quality assessment in CABG using transient time flow measurement (TTFM) with a focus on its use in arterial grafting.

Consensus statement-graft treatment in cardiovascular bypass graft surgery.

Coronary artery bypass grafting (CABG) is and continues to be the preferred revascularization strategy in patients with multivessel disease. Graft selection has been shown to influence the outcomes following CABG. During the last almost 60 years saphenous vein grafts (SVG) together with the internal mammary artery have become the standard of care for patients undergoing CABG surgery. While there is little doubt about the benefits, the patency rates are constantly under debate. Despite its acknowledged limitations in terms of long-term patency due to intimal hyperplasia, the saphenous vein is still the most often used graft. Although reendothelialization occurs early postoperatively, the process of intimal hyperplasia remains irreversible. This is due in part to the persistence of high shear forces, the chronic localized inflammatory response, and the partial dysfunctionality of the regenerated endothelium. "No-Touch" harvesting techniques, specific storage solutions, pressure controlled graft flushing and external stenting are important and established methods aiming to overcome the process of intimal hyperplasia at different time levels. Still despite the known evidence these methods are not standard everywhere. The use of arterial grafts is another strategy to address the inferior SVG patency rates and to perform CABG with total arterial revascularization. Composite grafting, pharmacological agents as well as latest minimal invasive techniques aim in the same direction. To give guide and set standards all graft related topics for CABG are presented in this expert opinion document on graft treatment.

Expert systematic review on the choice of conduits for coronary artery bypass grafting: endorsed by the European Association for Cardio-Thoracic Surgery (EACTS) and The Society of Thoracic Surgeons (STS).

PREAMBLE: The finalized document was endorsed by the EACTS Council and STS Executive Committee before being simultaneously published in the European Journal of Cardio-thoracic Surgery (EJCTS) and The Annals of Thoracic Surgery (The Annals) and the Journal of Thoracic and Cardiovascular Surgery (JTCVS).

Myocardial Revascularization in Patients With Ischemic Cardiomyopathy: For Whom and How.

Background Myocardial revascularization has been advocated to improve myocardial function and prognosis in ischemic cardiomyopathy (ICM). We discuss the evidence for revascularization in patients with ICM and the role of ischemia and viability detection in guiding treatment. Methods and Results We searched for randomized controlled trials evaluating the prognostic impact of revascularization in ICM and the value of viability imaging for patient management. Out of 1397 publications, 4 randomized controlled trials were included, enrolling 2480 patients. Three trials (HEART [Heart Failure Revascularisation Trial], STICH [Surgical Treatment for Ischemic Heart Failure], and REVIVED [REVascularization for Ischemic VEntricular Dysfunction]-BCIS2) randomized patients to revascularization or optimal medical therapy. HEART was stopped prematurely without showing any significant difference between treatment strategies. STICH showed a 16% lower mortality with bypass surgery compared with optimal medical therapy at a median follow-up of 9.8 years. However, neither the presence/extent of left ventricle viability nor ischemia interacted with treatment outcomes. REVIVED-BCIS2 showed no difference in the primary end point between percutaneous revascularization or optimal medical therapy. PARR-2 (Positron Emission Tomography and Recovery Following Revascularization) randomized patients to imaging-guided revascularization versus standard care, with neutral results overall. Information regarding the consistency of patient management with viability testing results was available in ≈65% of patients (n=1623). No difference in survival was revealed according to adherence or no adherence to viability imaging. Conclusions In ICM, the largest randomized controlled trial, STICH, suggests that surgical revascularization improves patients' prognosis at long-term follow-up, whereas evidence supports no benefit of percutaneous coronary intervention. Data from randomized controlled trials do not support myocardial ischemia or viability testing for treatment guidance. We propose an algorithm for the workup of patients with ICM considering clinical presentation, imaging results, and surgical risk.

Association between sternal wound complications and 10-year mortality following coronary artery bypass grafting.

OBJECTIVE: To evaluate the association between sternal wound complications (SWC) and long-term mortality in the Arterial Revascularization Trial. METHODS: Participants in the Arterial Revascularization Trial were stratified according to the occurrence of postoperative SWC. The primary outcome was all-cause mortality at long-term follow-up. The secondary outcome was major adverse cardiovascular events. RESULTS: Three thousand one hundred two patients were included in the analysis; the median follow-up was 10 years. 115 patients (3.7%) had postoperative SWC: 85 (73.9%) deep sternal wound infections and 30 (26.1%) sterile SWC that required sternal reconstruction. Independent predictors of SWC included diabetes (odds ratio [OR], 2.77; 95% CI, 1.79-4.30; P < .001), female sex (OR, 2.73; 95% CI, 1.71-4.38; P < .001), prior stroke (OR, 2.59; 95% CI, 1.12-5.98; P = .03), chronic obstructive pulmonary disease (OR, 2.44; 95% CI, 1.60-3.71; P < .001), and use of bilateral internal thoracic artery (OR, 1.70; 95% CI, 1.12-2.59; P = .01). Postoperative SWC was significantly associated with long-term mortality. The Kaplan-Meier survival estimate was 91.3% at 5 years and 79.4% at 10 years in patients without SWC, and 86.1% and 64.3% in patients with SWC (log rank P < .001). The rate of major adverse cardiovascular events was also higher among patients who had SWC (n = 51 [44.3%] vs 758 [25.4%]; P < .001). Using multivariable analysis, the occurrence of SWC was independently associated with long-term mortality (hazard ratio, 1.81; 95% CI, 1.30-2.54; P < .001). CONCLUSIONS: In the Arterial Revascularization Trial, postoperative SWC although uncommon were significantly associated with long-term mortality.

Graft flow evaluation with intraoperative transit-time flow measurement in off-pump versus on-pump coronary artery bypass grafting.

Objective: We aimed to compare transit-time flow measurement (TTFM) parameters for on-pump (ONCAB) and off-pump (OPCAB) coronary artery bypass procedures. Methods: The database of the Registry for Quality AssESsmenT with Ultrasound Imaging and TTFM in Cardiac Bypass Surgery (REQUEST) study was retrospectively reviewed. Only single grafts were included (ie, no sequential or Y/T grafts). Primary end points were mean graft flow (MGF), pulsatility index (PI), diastolic fraction (DF), and backflow (BF). Unadjusted and propensity score-matching comparisons were performed. Results: Of 1016 patients in the REQUEST registry, 846 had at least 1 graft for which TTFM was performed. Of these, 512 patients (60.6%) underwent ONCAB and 334 (39.4%) OPCAB procedures. Mean arterial pressure (MAP) during measurements was higher in the OPCAB group. After propensity score-matching, 312 well balanced pairs were left. In these matched patients, MGF was higher for the ONCAB versus the OPCAB group (32 vs 28 mL/min, respectively, for all grafts [P < .001]; 30 vs 27 mL/min for arterial grafts [P = .002]; and 35 vs 31 mL/min for venous grafts [P = .006], respectively). PI was lower in the ONCAB group (2.1 vs 2.3, for all grafts; P < .001). Diastolic fraction was slightly lower in the ONCAB group (65% vs 67.5%; P < .001). The backflow was also lower in the ONCAB group (0.6 vs 1.3; P < .001) with trends similar to MGF and PI for venous and arterial grafts. There were 21 (3.3%) revisions in the OPCAB group and 14 (2.1%) in the ONCAB group (P = .198). Conclusions: ONCAB surgery was associated with higher MGF and lower PI values, especially in venous grafts. Different TTFM cutoff values for ONCAB versus OPCAB surgery might be considered.

Single versus multiple arterial grafting in diabetic patients at 10 years: the Arterial Revascularization Trial.

AIMS: To evaluate the impact of multiple arterial grafting (MAG) vs. single arterial grafting (SAG) in a post hoc analysis of 10-year outcomes in patients with diabetes mellitus (DM) from the Arterial Revascularization Trial (ART). METHODS AND RESULTS: The primary endpoint was all-cause mortality and the secondary endpoint was a composite of major adverse cardiac events (MACE) at 10-year follow-up. Patients were stratified by diabetes status (non-DM and DM) and grafting strategy (MAG vs. SAG). A total of 3020 patients were included in the analysis; 716 (23.7%) had DM. Overall, 55.8% non-DM patients received MAG and 44.2% received SAG, while 56.6% DM patients received MAG and 43.4% received SAG. The use of MAG compared with SAG was associated with lower 10-year mortality for both non-DM [17.7 vs. 21.0%, adjusted hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.72-1.06] and DM patients (21.5 vs. 29.9%, adjusted HR 0.65, 95% CI 0.48-0.89; P for interaction = 0.12). For both groups, the rate of 10-year MACE was also lower for MAG vs. SAG. Overall, deep sternal wound infections (DSWIs) were uncommon but more frequent in the MAG vs. SAG group in both non-DM (3.3 vs. 2.1%) and DM patients (7.9 vs. 4.8%). The highest rates of DSWI were in insulin-treated patients receiving MAG (9.6 vs. 6.3%, when compared with SAG). CONCLUSION: In this post hoc analysis of the ART, MAG was associated with substantially lower mortality rates at 10 years after coronary artery bypass grafting in patients with DM. Patients with DM receiving MAG had a higher incidence of DSWI, especially if insulin dependent.

Effects of the harvesting technique and external stenting on progression of vein graft disease 2 years after coronary artery bypass.

OBJECTIVES: In a post hoc analysis of the VEST III trial, we investigated the effect of the harvesting technique on saphenous vein graft (SVG) patency and disease progression after coronary artery bypass grafting. METHODS: Angiographic outcomes were assessed in 183 patients undergoing open (126 patients, 252 SVG) or endoscopic harvesting (57 patients, 114 SVG). Overall SVG patency was assessed by computed tomography angiography at 6 months and by coronary angiography at 2 years. Fitzgibbon patency (FP I, II and III) and intimal hyperplasia (IH) in a patient subset were assessed by coronary angiography and intravascular ultrasound, respectively, at 2 years. RESULTS: Baseline characteristics were similar between patients who underwent open and those who underwent endoscopic harvesting. Open compared with endoscopic harvesting was associated with higher overall SVG patency rates at 6 months (92.9% vs 80.4%, P = 0.04) and 2 years (90.8% vs 73.9%, P = 0.01), improved FP I, II and III rates (65.2% vs 49.2%; 25.3% vs 45.9%, and 9.5% vs 4.9%, respectively; odds ratio 2.81, P = 0.09) and reduced IH area (-31.8%; P = 0.04) and thickness (-28.9%; P = 0.04). External stenting was associated with improved FP I, II and III rates (odds ratio 2.84, P = 0.01), reduced IH area (-19.5%; P < 0.001) and thickness (-25.0%; P < 0.001) in the open-harvest group and reduced IH area (-12.7%; P = 0.01) and thickness (-9.5%; P = 0.21) in the endoscopic-harvest group. CONCLUSIONS: A post-hoc analysis of the VEST III trial showed that open harvesting is associated with improved overall SVG patency and reduced IH. External stenting reduces SVG disease progression, particularly with open harvesting.

Prognostic factors of 10-year mortality after coronary artery bypass graft surgery: a secondary analysis of the arterial revascularization trial.

OBJECTIVES: The objective of this investigation was to determine the preoperative prognostic factors of long-term (10-year) mortality in patients treated with isolated coronary artery bypass graft surgery in the arterial revascularization trial (ART). METHODS: A post hoc analysis of the ART was conducted. Cumulative 10-year mortality was estimated using the Kaplan-Meier method. Prospectively collected preoperative data were used to determine the prognostic factors of 10-year all-cause mortality in patients who participated in the ART (Cox proportional hazards model). RESULTS: A total of 3102 patients who participated in the ART were included in the analysis. Ten-year follow-up was completed in 3040 patients (98%). A total of 644 patients (20.8%) had died by 10 years. Preoperative factors that were identified as statistically significant predictors of 10-year mortality in the multivariable analysis (all P ≤ 0.01) were: left ventricular ejection fraction, atrial fibrillation, age, diabetes, prior cerebrovascular event (stroke or transient ischaemic attack), serum creatinine and smoking status. The following variables were significantly associated in univariable models but did not retain significance in the multivariable model for mortality: non-Caucasian ethnicity, hypertension, peripheral vascular disease, chronic obstructive pulmonary disease and prior myocardial infarction. CONCLUSIONS: Independent predictors of 10-year mortality in the ART were multifactorial. Several key independent predictors of 10-year mortality in the ART were identified including: heart function, renal function, cerebrovascular disease, age, atrial fibrillation, smoking status and diabetes. Understanding which preoperative variables influence long-term outcome after coronary artery bypass grafting may help to target treatments to those at higher risk to reduce mortality.

Effect of total arterial grafting in the Arterial Revascularization Trial.

OBJECTIVES: The Arterial Revascularization Trial (ART) was designed to compare 10-year survival in bilateral versus single internal thoracic artery grafts. The intention-to-treat analysis has showed comparable outcomes between the 2 groups but an explanatory analysis suggested that those receiving 2 or more arterial grafts had better survival. Whether the exclusive use of arterial grafts provide further benefit is unclear. METHODS: We performed an exploratory analysis of the ART based on conduits actually received (as-treated principle). From ART cohort, only patients receiving at least 3 grafts were included. The final population consisted of 1084, 1010, and 390 patients in the single arterial graft (SAG) group, in the multiple arterial graft (MAG) group (2 or more arterial grafts with additional saphenous veins) and total arterial graft (TAG) group (3 or more arterial grafts only) respectively. Inverse probability of treatment weighting was used for comparison. RESULTS: When compared with the SAG group, there was a significant trend toward a reduction of 10-year mortality in the MAG and TAG group (test for trend P = .02). The TAG group was associated with the lowest risk of late mortality (hazard ratio, 0.68; 95% confidence interval, 0.48-0.96; P = .03) and with a significant risk reduction of the composite of death/myocardial infarction/stroke and repeat revascularization (hazard ratio, 0.71; 95% confidence interval, 0.53-0.94; P = .02). CONCLUSIONS: When compared with SAG, both MAG and TAG represent valuable strategies to improve clinical outcomes following coronary artery bypass grafting but TAG can potentially provide further benefit.