CABG
RAPCO: Radial artery grafting is superior to both RITA and SVG in patients undergoing CABG
Key Points:
- Recent guidelines have supported the use of arterial grafts over venous grafts in coronary artery bypass grafting (CABG), but there has yet to be a single randomized trial examining long-term cardiovascular outcomes with these different grafting methods.
- In the RAPCO study, patients undergoing CABG were randomized to either a) radial artery (RA) grafting versus right internal thoracic artery (RITA) grafting or b) radial artery (RA) grafting versus saphenous vein grafting (SVG). The primary outcome of interest was MACE, a composite of cardiovascular mortality, acute MI, and revascularization.
- RA grafting was superior to both RITA and SVG grafting over 15 years of follow-up.
Extended outcomes of BEST: No difference in MACE between PCI and CABG in MVD at 12 years, but higher repeat revascularization and spontaneous MI in PCI arm
Key Points:
- Previous studies have demonstrated the superiority of CABG over PCI in the treatment of multivessel disease; however, most studies were performed without the use of newer second-generation stents.
- The two-year outcomes of the BEST trial demonstrated superiority of CABG compared to PCI with second-generation everolimus-eluting DES; however, the authors then pursued an extended outcome analysis up to a median follow-up of 11.8 years.
- There was no difference between PCI and CABG at extended follow-up in the primary outcome composite of all-cause death, MI, and total revascularization. However, the rate of spontaneous MI and repeat revascularization was higher in the PCI arm.
- IVUS use reduced the incidence of the primary composite amongst patients undergoing PCI.
Post-Hoc Analysis of ISCHEMIA Trial: The Choice of Myocardial Infarction Definition Influences Clinical Interpretation of Results
A recent study by Dr. Bernard R. Chaitman, published in Circulation investigated the impact on clinical interpretation of using different definitions for myocardial infarctions in the ISCHEMIA trial.
SYNTAX III REVOLUTION Trial: Non-invasive CT Scanning as a Potential Alternative to Invasive Coronary Angiography for Treatment Decision-Making in Patients with Complex Coronary Artery Disease FFRCT or multi-slice CT scanning changed heart team’s treatment decision-making and procedural planning in 1/5th of the patients
A cross-sectional observational study enrolling 223 patients with 3-vessel coronary artery disease, has shown that compared to conventional invasive coronary angiography, a noninvasive physiology assessment using fractional flow reserve CT scanning (FFRCT or multi-slice CT scanning) changed heart team’s treatment decision-making and procedural planning in 1/5th of the patients.
The SYNTAX III REVOLUTION Trial was a randomized, multi-center study which randomized two heart teams to make a treatment decision between percutaneous coronary interventions (PCI) and coronary artery bypass grafting (CABG) using either coronary computed tomography angiography (CTA) or conventional invasive angiography while blinded to the other imaging modality. The study included patients with complex coronary artery disease, defined as, left main (isolated, or associated with 1, 2 or 3 vessel disease) or de novo 3-vessel coronary artery disease (DS ≥50%), who were able to receive cardiac CT with a multi-slice CT scanner. Coronary CTA was performed with the GE Revolution CT scanner that has a nominal spatial resolution of 230 microns along the X–Y planes, a rotational speed of 0.28 s, and a Z-plane coverage of 16 cm enabling to image the heart in one heartbeat. Patients with concomitant atrial fibrillation, cardiac valve disease and prior history of PCI or CABG were excluded from the study. The primary outcome was the inter-rater agreement (assessed by Cohen’s Kappa Kappa; a value of 0.82) on revascularization strategy of two heart teams by employing the use of either an “Angio-first” algorithm or a “CT First” algorithm 1 to 2 weeks after patient enrollment. The addition of FFRCT changed the treatment decision in 7% of the patients and modified selection of vessels for revascularization in 12%. With conventional angiography as a reference, FFRCT assessment resulted in reclassification of 14% of patients from intermediate and high to low SYNTAX score tertile.
The American and European guidelines recommend a heart team based approach for the decision-making process regarding the revascularization strategy and recommend the evaluation of the anatomical complexity using the SYNTAX score. Patients with SYNTAX scores >34 have been found to do much better with bypass surgery than those with lower SYNTAX scores. The SYNTAX scores can be divided into three tertiles. Higher scores signify complex conditions and indicate greatest risks to patients undergoing PCI. Calculation of the SYNTAX score takes into account complex lesions including bifurcations, chronic total occlusions, thrombus, calcification, and small diffuse disease with a total of 11 measures of lesion complexity. The score ranges from 0 to greater than 60 in very complex coronary anatomy.
Previously validated SYNTAX II score utilizes SYNTAX I score and then combines it with clinical prognostic variables such as age, creatinine clearance, gender, left main vessel involvement, left ventricular ejection fraction, chronic obstructive pulmonary disease (COPD) and peripheral vascular disease (PVD) in order to guide selection between PCI and CABG for patients with multivessel coronary disease. The results of the SYNTAX III Trial suggest the potential feasibility of a treatment decision-making and planning that stems from a non-invasive imaging modality and clinical information.
Treatment with Statins, RAAS Inhibitors and Platelet Inhibitors After CABG is Essential, While the Use of Beta-blockers is Questionable: Swedish Study Secondary prevention medications after coronary artery bypass grafting and long-term survival: a population-based longitudinal study from the SWEDEHEART registry
In a recent study published in the European Heart Journal, Erik Björklund et al. found that the secondary prevention medications, such as statins and renin-angiotensin-aldosterone system (RAAS) inhibitors, and platelet inhibitors used after coronary artery bypass grafting (CABG) are essential while the use of B-blockers had no association with survival and is questionable.
No significant association between myocardial viability & long-term survival benefit of CABG in patients with ischemic cardiomyopathy Results of a 10-year follow-up STICH trial & subsequent myocardial viability sub-study
According to a new study published in The New England Journal of Medicine (NEJM) based on a 10-year follow-up STICH trial, no association was found between myocardial viability as a long-term survival benefit of CABG in patients with ischemic cardiomyopathy.
Study Shows Preoperative Fractional Flow Reserve Associated with 6-Month Anastomotic Graft Functionality in Patients Undergoing Coronary Artery Bypass Graft IMPAG trial
A team led by Dr David Glineur working in Canada and Europe on the IMpact of Preoperative fractional flow reserve on Arterial bypass Graft anastomotic function(IMPAG) trial published in European Heart Journal that fractional flow reserve(FFR) measured before surgical revascularization and anastomotic function are significantly related to each other at 6 months with a cut-off value of 0.78. They also found that measuring FFR before Coronary Artery Bypass Grafting(CABG)surgery had improved function of the anastomotic graft.
