Native coronary artery patency after coronary artery bypass surgery

Stingray-ADR technique creating a channel between double CTO lesions in a previous CABG patient

Patients presenting with previous coronary artery bypass grafting (CABG) exhibit an accelerated progression of atherosclerosis in native coronary arteries following surgical revascularization. When saphenous vein grafts (SVGs) become diseased or occluded, the treatment of the entire native vessels becomes significantly more challenging. Herein, we present a patient who was admitted to our hospital due to heart failure. He had undergone CABG 12 years earlier, with a left internal mammary artery (LIMA) grafted to the left anterior descending (LAD) artery, a saphenous vein graft (SVG) to the first diagonal branch (D1), and another SVG to the right coronary artery (RCA). Furthermore, a stent was implanted in the SVG to the RCA five years ago. During the current admission, angiography identified multiple chronic total occlusion (CTO) lesions in the native proximal LAD and RCA, as well as in the SVG-D1, along with in-stent occlusion of the SVG to RCA. The percutaneous coronary intervention (PCI) strategy primarily focused on recanalization of the CTO in the RCA. We successfully implemented the Stingray-based antegrade dissection reentry (ADR) technique in the LAD CTO lesion to establish a critical channel. Leveraging this channel, we subsequently accomplished retrograde recanalization of the RCA CTO via septal collateral vessels. This case demonstrates that the Stingray-ADR technique can serve as a promising and effective approach in facilitating the recanalization of more complex multi-vessel CTO lesions. Clinical trial number: Not applicable.

Comparison of Fractional Flow Reserve and Myocardial Perfusion Imaging in Saphenous Vein Grafts

BACKGROUND

Revascularization decision-making for saphenous vein grafts (SVGs) relies on angiographic lesion severity estimation, as studies on fractional flow reserve (FFR) for detecting ischemia in SVGs are scarce.

AIMS

To compare FFR and quantitative coronary angiography (QCA) of SVGs against myocardial perfusion imaging (MPI) and to establish an optimal FFR threshold for SVGs.

METHODS

This cross-sectional registry study included symptomatic patients with prior coronary artery bypass grafting who underwent single-photon emission computed tomography, positron emission tomography, or stress perfusion cardiac magnetic resonance imaging and had FFR measurements of ≥ 1 SVGs. We matched the myocardial territory supplied by the SVGs to ischemia on MPI. The optimal FFR threshold for SVGs was determined using the Youden index. Diagnostic performance measures were calculated and compared for FFR (0.80 and the optimal threshold) and for QCA (diameter stenosis ≥ 50%).

RESULTS

This study included 80 patients (mean age 73 ± 7 years, 68 [85%] male) with 94 SVGs, of which 38 (40%) supplied ischemic myocardium. Areas under the curve between FFR and QCA were comparable (0.73 vs. 0.65, p = 0.181). The optimal cutoff value of FFR was 0.94. FFR ≤ 0.94 showed higher sensitivity (63%) and negative predictive value (75%) compared to FFR ≤ 0.80 (32% [p < 0.001] and 64% [p = 0.007]) and QCA (37% [p = 0.002] and 65% [p = 0.021]), but with lower specificity (75%) than FFR ≤ 0.80 (84%, p = 0.021). Positive predictive value and overall accuracy were similar across all methods.

CONCLUSIONS

FFR and QCA had comparable moderate diagnostic performance for detecting SVG failure determined by MPI. The optimal FFR cutoff in SVGs is higher than 0.80, resulting in higher sensitivity and negative predictive value compared to FFR ≤ 0.80 and QCA, at the expense of reduced specificity.

Preventing Distal Embolization of Coils After Therapeutic Graft Closure: The CRISP Technique

Patients with coronary artery bypass surgery will invariably experience graft failure. In this setting, treatment of the native vessel is recommended. After successful native vessel intervention, competitive flow from a patent graft may limit the durability of native vessel intervention, and thus therapeutic graft closure is usually recommended. Graft closure is frequently achieved with coils, but a recognized complication with coils is distal embolization during or after deployment. The presence of disease or tortuosity in grafts may allow stable deployment of coils and prevent this. However, with relatively patent grafts, it may be difficult to deploy coils without a risk of embolization. To overcome this problem, we propose a new technique where we strategically deploy and fashion a partially crushed stent in the body of the graft to serve as a plug to hold coils and prevent distal embolization, called the CRISP (CRushed In situ Stent Plug) technique.

Myocardial infarction in multivessel disease: Does presence of chronic total occlusion make a difference?

BACKGROUND AND AIMS

Myocardial infarction (MI) in multivessel disease (MVD) and chronic total occlusion (CTO) is associated with high mortality. However, all-cause mortality of matched cohort without a CTO is unclear. Our aim was to analyse clinical characteristics, presenting symptoms, and survival of patients with MI in MVD and the possible impact of CTO on 1-year mortality.

METHODS

All MI patients with MVD (two or three vessel disease) hospitalized in our center from January 2020 to September 2022 (1309 patients) were selected. We conducted a propensity score matching (PSM) analysis based on age, gender, type of MI, and compared patients with CTO (CTO group, n = 90) and without CTO (Control group, n = 90).

RESULTS

We observed no difference in presenting clinical symptoms and initial heart rhythm between the groups. 1-year follow-up shows all-cause mortality rate of 23.3 % (n = 21) in the CTO group (Mean survival [MS] = 292.1 days, 95 % CI = 263.8 to 320.4) and 18.9 % (n = 17) in the Control group (MS = 310.2 days, 95 % CI = 285.3 to 335.2), p = 0.44. PCI alone was performed in 64.4 % (n = 58) in both groups, CABG in 18.8 % (n = 17) and 24.4 % (n = 22) (CTO vs. Control group respectively). Combination of PCI and CABG occurred in 8.8 % (n = 8) in both groups. Conservative treatment was chosen for 7 CTO and 2 Control group patients.

CONCLUSION

We observed no 1-year mortality difference in patients with MI, MVD and a CTO compared to a matched cohort of patients with MI, MVD without CTO. Excellent 1-year survival was observed in patients treated by CABG, irrespective of CTO presence.

Sex Disparities in In-Hospital Outcomes After Percutaneous Coronary Intervention (PCI) in Patients With Acute Myocardial Infarction and a History of Coronary Artery Bypass Grafting (CABG): A Cross-Sectional Study

Background and Aims

The role of sex disparities in in-hospital outcomes after percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in patients with a history of coronary artery bypass grafting (CABG) remains underexplored. This study aimed to identify sex disparities in in-hospital outcomes after PCI in patients with AMI and a history of CABG.

Methods

Using the National Inpatient Sample database, we identified patients hospitalized for AMI with a history of CABG who underwent PCI between 2016 and 2019. 1:1 propensity score matching was used to minimize standardized mean differences of baseline variables and compare in--hospital outcomes.

Results

In total, 75,185 weighted hospitalizations of patients were identified. Compared with male patients, female patients exhibited elevated risks of in-hospital mortality (3.72% vs. 2.85%; adjusted odds ratio [aOR] 1.48; 95% confidence interval [CI] 1.14-1.93), major adverse cardiac or cerebrovascular events (MACCEs) (4.96% vs. 3.75%; aOR 1.46; 95% CI 1.18-1.82), bleeding (4.91% vs. 3.01%; aOR 1.56; 95% CI 1.27-1.79), and longer length of stay (4.64 days vs. 3.96 days; β 0.42; 95% CI 0.28-0.55). After propensity matching, female patients remained associated with increased risks of in-hospital mortality (3.81% vs. 2.81%; aOR 1.37; 95% CI 1.06-1.78), MACCEs (5.08% vs. 3.84%; aOR 1.35; 95% CI 1.08-1.70), bleeding (5.03% vs. 3.11%; aOR 1.57; 95% CI 1.24-2.00), and longer length of stay (4.61 ± 4.76 days vs. 4.06 ± 4.10 days; β 0.39; 95% CI 0.18-0.59). Female patients aged > 60 years were more vulnerable to in-hospital mortality than were their male counterparts (3.06% vs. 4.15%; aOR 1.56; 95% CI 1.18-2.05).

Conclusions

Female patients who underwent PCI for AMI with a history of CABG had higher risks of in-hospital mortality, MACCEs, bleeding, and longer length of stay, with in-hospital mortality rates being particularly pronounced among older patients.

Impella Versus Non-Impella for Nonemergent High-Risk Percutaneous Coronary Intervention

The benefit of mechanical circulatory support with Impella (Abiomed, Inc., Danvers, Massachusetts) for high-risk percutaneous coronary intervention (HR-PCI) is uncertain. PROTECT III registry data showed improved outcomes with Impella compared with historical data (PROTECT II) but lack a direct comparison with the HR-PCI cohort without Impella support. We retrospectively identified patients meeting the PROTECT III inclusion criteria for HR-PCI and compared this group (non-Impella cohort [NonIMP]) with the outcomes data from the PROTECT III registry (Impella cohort). Baseline differences were balanced using inverse propensity weighting. The coprimary outcome was major adverse cardiac events (MACE) in-hospital and at 90 days. A total of 283 patients at great risk did not receive Impella support; 200 patients had 90-day event ascertainment and were included in the inverse propensity weighting analysis and compared with 504 patients in the Impella cohort group. After calibration, few residual differences remained between groups. The primary outcome was not different in-hospital (3.0% vs 4.8%, p = 0.403) but less in NonIMP at 90 days (7.5% vs 13.8%, p = 0.033). Periprocedural vascular complications, bleeding, and transfusion rate did not differ between groups; however, acute kidney injury occurred more frequently in the NonIMP group (10.5% vs 5.4%, p = 0.023). In conclusion, under identical HR-PCI inclusion criteria for Impella use in PROTECT III, an institutional non-Impella-supported HR-PCI cohort showed similar MACE in-hospital but fewer MACE at 90 days, whereas there was no signal for periprocedural harm with Impella use. These results do not support routine usage of Impella for patients with HR-PCI.

Native coronary artery or bypass graft percutaneous coronary intervention in patients after previous coronary artery bypass surgery: A large nationwide analysis from the Netherlands Heart Registration

BACKGROUND

Patients with previous coronary artery bypass surgery (CABG) who require repeat revascularization frequently undergo percutaneous coronary intervention (PCI). We sought to identify factors associated with the decision to intervene on the native vessel versus a bypass graft and investigate their outcomes in a large nationwide prospective registry.

METHODS

We identified patients who underwent PCI with a history of prior CABG from the Netherlands Heart Registration between 2017 and 2021 and stratified them by isolated native vessel PCI versus PCI including at least one venous- or arterial graft. The primary endpoint of major adverse cardiac events (MACE) was a composite of all-cause death and target vessel revascularization (TVR) at one-year post PCI. The key secondary endpoint was a composite of all-cause death, myocardial infarction (MI), and TVR at 30 days.

RESULTS

Out of 154,146 patients who underwent PCI, 12,822 (8.3%) had a prior CABG. Isolated native vessel PCI was most frequently performed (75.2%), while an acute coronary syndrome (ACS) presentation was most strongly associated with graft interventions. The primary outcome of MACE at one-year post PCI occurred more frequently in interventions including grafts compared with native vessels alone (19.7% vs. 14.3%; adjOR 1.267; 95% CI 1.101-1.457); p < 0.001) driven by TVR. There was however no difference in mortality or the key secondary endpoint between the two groups.

CONCLUSION

In this nationwide prospective registry, ACS presentation was strongly associated with bypass graft PCI. At one year after PCI, interventions including bypass grafts had a higher composite of MACE compared with isolated native vessel interventions.

A non-interventional cardiologist's guide to coronary chronic total occlusions

Coronary chronic total occlusions (CTO) are present in up to one-third of patients with coronary artery disease (CAD). It is thus essential for all clinical cardiologists to possess a basic awareness and understanding of CTOs, including optimal evaluation and management. While percutaneous coronary intervention (PCI) for CTO lesions has many similarities to non-CTO PCI, there are important considerations pertaining to pre-procedural evaluation, interventional techniques, procedural complications, and post-procedure management and follow-up unique to patients undergoing this highly specialized intervention. Distinct from other existing topical reviews, the current manuscript focuses on key knowledge relevant to non-interventional cardiologists.

Myocardial revascularization failure among patients requiring cardiac catheterization and secondary revascularization in contemporary clinical practice: Results of the REVASEC multicenter registry

BACKGROUND

Myocardial revascularization failure (MRF) and Secondary revascularization (SR) are contemporary interventional cardiology challenges.

AIM

To investigate the characteristics, management, and prognosis of patients with myocardial revascularization failure (MRF) and need for secondary revascularization (SR) in contemporary practice.

METHODS

The REVASEC study is a prospective registry (NCT03349385), which recruited patients with prior revascularization referred for coronary angiography at 19 centers. The primary endpoint is a patient-oriented composite (POCE) at 1 year, including death, myocardial infarction, or repeat revascularization.

RESULTS

A total of 869 patients previously revascularized by percutaneous intervention (83%) or surgery (17%) were recruited. MRF was found in 83.7% (41.1% stent/graft failure, 32.1% progression of coronary disease, and 10.5% residual disease). SR was performed in 70.1%, preferably by percutaneous intervention (95%). The POCE rate at 1 year was 14% in the overall cohort, with 6.4% all-cause death. In the multivariate analysis, lower POCE rates were found in the groups without MRF (9.4%) and with disease progression (11%) compared with graft/stent failure (17%) and residual disease (18%), hazard ratio 0.67 (95% confidence interval: 0.45-0.99), p = 0.043. At 1 year, the SR group had less chronic persistent angina (19% vs. 34%, p < 0.001), but a higher rate of repeat revascularization (9% vs. 2.9%, p < 0.001).

CONCLUSION

MRF was found in 84% of patients with prior revascularization referred for coronary angiography. Stent/graft failure and residual coronary disease were associated with a worse prognosis. SR provided better symptom control at the expense of a higher rate of new revascularization.

In-hospital Outcomes of Patients With and Without Previous Coronary Artery Bypass Graft Surgery Who Present With a Non-ST-Segment Elevation Myocardial Infarction

The clinical course of patients with a previous coronary artery bypass graft surgery (CABG) presenting with non-ST-elevation myocardial infarction (NSTEMI) is not well defined. We aimed to compare the management and outcomes of patients with and without previous CABG who present with an NSTEMI. Patients hospitalized with an NSTEMI between 2002 and 2018 were identified from the National Inpatient Sample. The baseline characteristics and outcomes of patients with and without a previous CABG were compared. The outcomes included the rates of invasive procedures (defined as coronary angiography, percutaneous coronary intervention [PCI], or CABG), and its individual components, and in-hospital mortality. A total of 1,445,545 cases of NSTEMI were found, of which 133,691 (9.3%) had a previous CABG. Patients with a previous CABG were older (72.4 vs 68.6 years, p <0.001), more likely men (68.8% vs 56.9%, p <0.001), and of White race (79.7% vs 74.8%, p <0.001). The previous CABG cohort had lower rates of invasive procedures (50.4% vs 65.6%, p <0.001), PCI (23.7% vs 32.0%, p <0.001), or CABG (1.2% vs 10.6%; p <0.001) in the unmatched analysis. The results were consistent in the propensity score-matched analysis with the previous CABG group less likely to receive any invasive procedures (odds ratio [OR] 0.48, 95% confidence interval [CI] 0.47 to 0.49), including coronary angiography (OR 0.54, 95% CI 0.53 to 0.55), PCI (OR 0.66, 95% CI 0.64 to 0.67), or repeat CABG (OR 0.11, 95% CI 0.10 to 0.12). Moreover, the risk of in-hospital mortality was higher in the previous CABG group (OR 1.15, 95% CI 1.10 to 1.21). In the subset of patients who were revascularized in both groups, this excess mortality was no longer observed (OR 0.82, 95% CI 0.66 to 1.03). In conclusion, a previous CABG in patients who present with NSTEMI is associated with lower rates of invasive procedures and revascularization and higher in-hospital mortality than patients without a previous CABG.

A Travel Through Time: Percutaneous Management of Degenerated Coronary Saphenous Vein Grafts

Managing coronary saphenous vein graft failure has remained an unmet need since the inception of interventional cardiology. The present case constitutes an opportunity to revisit percutaneous strategies to treat saphenous vein graft failure, providing a travel though interventional strategies and showing a contemporary approach to this problem. (Level of Difficulty: Intermediate.).

Characteristics of Radial Artery Coronary Bypass Graft Failure and Outcomes Following Subsequent Percutaneous Coronary Intervention

BACKGROUND

When patients with prior coronary artery bypass grafting (CABG) undergo percutaneous coronary intervention (PCI), targeting the native vessel is preferred. Studies informing such recommendations are based predominantly on saphenous vein graft (SVG) PCI. There are few data regarding arterial graft intervention, particularly to a radial artery (RA) graft.

OBJECTIVES

The aim of this study was to report the characteristics of arterial graft stenoses and evaluate the feasibility of RA PCI.

METHODS

This study included 2,780 consecutive patients with prior CABG undergoing PCI between 2005 and 2018 who were prospectively enrolled in the MIG (Melbourne Interventional Group) registry. Data were stratified by PCI target vessel. RA graft PCI was compared with both native vessel (native PCI) and SVG PCI. Internal mammary graft PCI data were reported. The primary outcome was 3-year mortality.

RESULTS

Overall, 1,928 patients (69.4%) underwent native PCI, 716 (25.6%) SVG PCI, 86 (3.1%) RA PCI, and 50 (1.8%) internal mammary graft PCI. Compared with SVG PCI, the RA PCI cohort presented earlier after CABG, less frequently had acute coronary syndrome, and more commonly had ostial or distal anastomosis intervention (P < 0.005 for all). Compared with patients who underwent native PCI, those who underwent RA PCI were more likely to have diabetes and peripheral vascular disease (P < 0.001 for both) and to present with non-ST-segment elevation myocardial infarction (P = 0.010). The RA PCI group had no perforations or in-hospital myocardial infarctions, though no significant difference was found in periprocedural outcomes compared with either native or SVG PCI. No differences were found between RA PCI and either native or SVG PCI in 30-day outcomes or 3-year mortality.

CONCLUSIONS

Presenting and lesion characteristics differed between patients undergoing arterial compared with SVG PCI, implying a varied pathogenesis of graft stenosis. RA PCI appears feasible, safe, and where anatomically suitable, may be a viable alternative to native PCI.

Why and How Should We Treat Chronic Total Occlusion? Evolution of State-of-the-Art Methods and Future Directions

Chronic total occlusions are considered the most complex coronary lesion in interventional cardiology. The absence of visible lumen on angiography obscures the vessel course and makes vessel wiring unlikely with conventional techniques. Often a source of severe ischemia, chronic occlusions are also markers of advanced atherosclerosis that brings other complex features including lesion length, bifurcations, calcification, adverse vessel remodelling, distal disease, and anatomic distortion from previous bypass grafting. Often advanced atherosclerosis is associated with patient characteristics like left ventricular dysfunction, previous coronary bypass surgery, or multivessel disease that increase procedural demands and hazards. To accommodate these challenges new techniques and dedicated technologies have been developed. When applied to appropriate patients, these advances have improved procedural success, safety, and outcomes. Our aim is to provide the general cardiologist with an overview of these advances that can serve as a basis for counselling patients considered for revascularization.

Trends and Outcomes of Myocardial Infarction in Patients With Previous Coronary Artery Bypass Surgery

Data on myocardial infarction (MI) treatment in patients with previous coronary artery bypass grafting (CABG) is limited. We queried the Nationwide Readmissions Database to identify hospitalizations of patients with MI from 2016 to 2019. Among hospitalized patients presenting with MI, 10.3% had previous CABG. Patients with MI who had previous CABG were less likely to be revascularized than those without previous CABG for both ST-segment elevation MI (STEMI) (46.4% vs 68.4%) and non-ST-segment elevation MI (NSTEMI) (30.8% vs 36.7%). CABG was associated with a lower risk of death in NSTEMI patients (odds ratio [OR] 0.84, 95% confidence interval [CI] 0.82 to 0.86), but a higher risk in STEMI patients (OR 1.06, 95% CI 1.01 to 1.13). Revascularization was associated with a lower risk of in-hospital death in patients with previous CABG presenting with STEMI (OR 0.30, 95% CI 0.26 to 0.35) and NSTEMI (OR 0.21, 95% CI 0.19 to 0.23).

The Role of Angiogenesis and Arteriogenesisin Myocardial Infarction and Coronary Revascularization

Surgical myocardial revascularization is associated with long-term survival benefit in patients with multivessel coronary artery disease. However, the exact biological mechanisms underlying the clinical benefits of myocardial revascularization have not been elucidated yet. Angiogenesis and arteriogenesis biologically leading to vascular collateralization are considered one of the endogenous mechanisms to preserve myocardial viability during ischemia, and the presence of coronary collateralization has been regarded as one of the predictors of long-term survival in patients with coronary artery disease (CAD). Some experimental studies and indirect clinical evidence on chronic CAD confirmed an angiogenetic response induced by myocardial revascularization and suggested that revascularization procedures could constitute an angiogenetic trigger per se. In this review, the clinical and basic science evidence regarding arteriogenesis and angiogenesis in both CAD and coronary revascularization is analyzed with the aim to better elucidate their significance in the clinical arena and potential therapeutic use.

Quantitative Myocardial Perfusion Predicts Outcomes in Patients With Prior Surgical Revascularization

BACKGROUND

Patients with previous coronary artery bypass graft (CABG) surgery typically have complex coronary disease and remain at high risk of adverse events. Quantitative myocardial perfusion indices predict outcomes in native vessel disease, but their prognostic performance in patients with prior CABG is unknown.

OBJECTIVES

In this study, we sought to evaluate whether global stress myocardial blood flow (MBF) and perfusion reserve (MPR) derived from perfusion mapping cardiac magnetic resonance (CMR) independently predict adverse outcomes in patients with prior CABG.

METHODS

This was a retrospective analysis of consecutive patients with prior CABG referred for adenosine stress perfusion CMR. Perfusion mapping was performed in-line with automated quantification of MBF. The primary outcome was a composite of all-cause mortality and major adverse cardiovascular events defined as nonfatal myocardial infarction and unplanned revascularization. Associations were evaluated with the use of Cox proportional hazards models after adjusting for comorbidities and CMR parameters.

RESULTS

A total of 341 patients (median age 67 years, 86% male) were included. Over a median follow-up of 638 days (IQR: 367-976 days), 81 patients (24%) reached the primary outcome. Both stress MBF and MPR independently predicted outcomes after adjusting for known prognostic factors (regional ischemia, infarction). The adjusted hazard ratio (HR) for 1 mL/g/min of decrease in stress MBF was 2.56 (95% CI: 1.45-4.35) and for 1 unit of decrease in MPR was 1.61 (95% CI: 1.08-2.38).

CONCLUSIONS

Global stress MBF and MPR derived from perfusion CMR independently predict adverse outcomes in patients with previous CABG. This effect is independent from the presence of regional ischemia on visual assessment and the extent of previous infarction.

Contemporary coronary artery bypass graft surgery and subsequent percutaneous revascularization

Patients who have undergone coronary artery bypass graft (CABG) surgery are susceptible to bypass graft failure and progression of native coronary artery disease. Although the saphenous vein graft (SVG) was traditionally the most-used conduit, arterial grafts (including the left and right internal thoracic arteries and the radial artery) have improved patency rates. However, the need for secondary revascularization remains common, and percutaneous coronary intervention (PCI) has become the most common modality of secondary revascularization after CABG surgery. Procedural characteristics and clinical outcomes differ considerably from those associated with PCI in patients without previous CABG surgery, owing to altered coronary anatomy and differences in conduit pathophysiology. In particular, SVG PCI carries an increased risk of complications, and operators are shifting their focus towards embolic protection strategies and complex native-vessel interventions, increasingly using SVGs as conduits to facilitate native-vessel PCI rather than pursuing SVG PCI. In this Review, we discuss the differences in conduit pathophysiology, changes in CABG surgery techniques, and the latest evidence in terms of PCI in patients with previous CABG surgery, with a particular emphasis on safety and long-term efficacy. We explore the subject of contemporary CABG surgery and subsequent percutaneous revascularization in this complex patient population.

The Contemporary Management of Left Main Coronary Artery Disease

The 'gold standard' in the management of left main coronary artery disease has historically been coronary artery bypass surgery. Recent innovations in drug-eluting stent technology coupled with the increasing utility of physiology and imaging guidance for procedures have led to an evolving role of percutaneous coronary intervention in left main disease of low and intermediate anatomical complexity. This revascularization modality carries the clear advantage of being less invasive and significantly reduced recovery times. This practice is currently supported by international guidelines, however, it remains a controversial topic in the field of interventional cardiology, and the long-term outcomes of a percutaneous strategy have been questioned. This review describes the current evidence base for the assessment and choice of intervention in left main coronary artery disease. The percutaneous revascularization techniques and use of imaging to optimize procedures and improve clinical outcomes have been discussed.

Lesion characteristics and procedural complications of chronic total occlusion percutaneous coronary intervention in patients with prior bypass surgery: A meta-analysis

Coronary artery bypass graft (CABG) accelerates the prevalence of native coronary chronic total occlusion (CTO), and this kind of CTO shows extensive challenging and complex atherosclerotic pathology. As a result, the procedural success rate of percutaneous coronary intervention (PCI) is inferior to another kind of lesions. The present meta-analysis aims to compare the lesion characteristics and procedural complications of CTO-PCI in patients with or without prior CABG. A total of 8 studies, comprising of 13439 patients, published from inception to August 2021 were included in this meta-analysis. Results were pooled using random effects model and are presented as odds ratio (OR) with 95% confidence intervals (95% CIs). From the 13439 patients enrolled, 3349 (24.9%) patients had previous CABG and 10090 (75.1%) formed the control group in our analysis. For the clinical characteristic, compared to the non-CABG patients, prior CABG patients were older (OR, 3.98; 95% CI, 3.19-4.78; p < .001; I2  = 72%), had more male (OR, 1.30; 95% CI, 1.14-1.49; p < .001; I2  = 6%), diabetes mellitus (OR, 1.54; 95% CI, 1.36-1.73; p < .001; I2  = 37%), dyslipidemia (OR, 1.89; 95% CI, 1.33-2.69; p < .001; I2  = 81%), hypertension (OR, 1.88; 95% CI, 1.46-2.41; p < .001; I2  = 71%), previous myocardial infarction (OR, 1.94; 95% CI, 1.48-2.56; p < .001; I2  = 85%), and previous PCI (OR, 1.74; 95% CI, 1.52-1.98; p < .001; I2  = 22%). Non-CABG patents had more current smoker (OR, .45; 95% CI, 0.27-0.74; p < .001; I2  = 91%). BMI (OR, -0.01; 95% CI, -0.07-0.06; p = .85; I2  = 36%) were similar in both groups. For lesions location, the right coronary artery (RCA) was predominant target vessel in both groups (50.5% vs 48.7%; p＝.49), although, the left circumflex (LCX) was more frequently CTO in the prior CABG group (27.3% vs 18.9%; p＜.01), while left anterior descending artery (LAD) in non-CABG ones (16.0% vs 29.1%; p＜0.01). For lesions characteristics, prior CABG patients had more blunt stump (OR, 1.71; 95% CI, 1.46-2.00; p < .001; I2  = 40%), proximal cap ambiguity (OR, 1.45; 95% CI, 1.28-1.64; p < .001; I2  = 0.0%), severe calcifications (OR, 2.91; 95% CI, 2.19-3.86; p < .001; I2  = 83%), more bending (OR, 3.07; 95% CI, 2.61-3.62; p < .001; I2  = 0%), lesion length > 20 mm (OR, 1.59; 95% CI, 1.10-2.29; p = .01; I2  = 83%), inadequate distal landing zone (OR, 1.95; 95% CI, 1.75-2.18; p＜.001; I2  = 0.0%), distal cap at bifurcation (OR, 1.65; 95% CI, 1.46-1.88; p < .001; I2  = 0.0%), and higher J-CTO score (SMD, 0.52; 95% CI, 0.42-0.63; p < .001; I2  = 65%). But side branch at proximal entry (OR, 0.88; 95% CI, 0.72-1.07; p = .21; I2  = 45%), in-stent CTO (OR, 0.99; 95% CI, 0.86-1.14; p = .88; I2  = 0.0%), lack of interventional collaterals (OR, 0.80; 95% CI, 0.55-1.15; p = .23; I2  = 78%), and previously failed attempt (OR, 0.73; 95% CI, 0.48-1.11; p = .14; I2  = 89%) were similar in both groups. For complication, prior CABG patients had more perforation with need for intervention (OR, 1.91; 95% CI, 1.36-2.69; p < 0.001; I2  = 34%), contrast-induced nephropathy (OR, 3.40; 95% CI, 1.31-8.78; p = .01; I2  = 0.0%). Non-CABG patents had more tamponade (OR, 0.25; 95% CI, 0.09-0.72; p = .01; I2  = 0.0%), and the major bleeding complication (OR, 1.18; 95% CI, 0.57-2.44; p = .65; I2  = 0%) were no significant difference in both groups. In conclusion, Patients with prior CABG undergoing CTO-PCI have more complex lesion characteristics, though procedural complication rates were comparable.

Update on chronic total occlusion percutaneous coronary intervention

Chronic total occlusion (CTO) percutaneous coronary interventions (PCI) can be challenging to perform. The main indication for CTO PCI is to improve symptoms. Several contemporary studies have reported high CTO PCI success rates at experienced centers but success rates in all-comer registries remain low. Several scores can estimate the difficulty and the likelihood of success of CTO PCI. Dual arterial access and use of CTO crossing algorithms can improve the success and safety of CTO PCI. Intracoronary imaging can optimize stent expansion and minimize adverse cardiovascular events. While complications are more common in CTO PCI, careful planning and prompt diagnosis and treatment can prevent them or minimize their adverse consequences. In this article, we review contemporary data on the indications, safety and efficacy of CTO PCI.

Impact of target vessel choice on outcomes following percutaneous coronary intervention in patients with a prior coronary artery bypass graft

OBJECTIVES

To evaluate and compare characteristics and clinical outcomes of percutaneous coronary intervention (PCI) among target vessel types in patients with a prior coronary artery bypass graft (CABG) surgery.

BACKGROUND

Patients with a prior CABG often require repeat revascularization with PCI. Graft PCI has been associated with worse outcomes compared to native vessel PCI, yet the optimal PCI strategy in prior CABG patients remains unknown.

METHODS

We stratified prior CABG patients who underwent PCI at a tertiary-care center between 2009 and 2017 by target vessel type: native vessel, venous graft, and arterial graft. The primary outcome of major adverse cardiac events (MACE) was a composite of all-cause death, myocardial infarction, stent thrombosis, or target vessel revascularization up to 1 year post-PCI.

RESULTS

Prior CABG patients (n = 3983) represented 19.5% of all PCI interventions during the study period. PCI was most frequently performed on native vessels (n = 2928, 73.5%) followed by venous (n = 883, 22.2%) and arterial grafts (n = 172, 4.3%). Procedural success and complications were similar among the groups; however, slow- and no-reflow phenomenon was more common in venous graft PCI compared to native vessel PCI (OR 4.78; 95% CI 2.56-8.95; p < 0.001). At 1 year, there were no significant differences in MACE or in its individual components.

CONCLUSIONS

Target vessel choice did not appear to affect MACE at 1 year in a large cohort of patients with prior CABG undergoing PCI. Whether PCI of surgical grafts versus native arteries truly results in similar outcomes warrants further investigation in randomized controlled trials.

The Impact of Calcium on Chronic Total Occlusion Management

Coronary artery calcification is prevalent in chronic total occlusions (CTO), particularly in those of longer duration and post-coronary artery bypass. The presence of calcium predicts lower procedural success rates and a higher risk of complications of CTO percutaneous coronary intervention. Adjunctive imaging, including pre-procedural computed tomography and intracoronary imaging, are useful to understand the distribution and morphology of the calcium. Specialised guidewires and microcatheters, as well as penetration, subintimal entry and luminal re-entry techniques, are required to cross calcific CTOs. The use of both atherectomy devices and balloon-based calcium modification tools has been reported during CTO percutaneous coronary intervention, although they are limited by concerns regarding safety and efficacy in the subintimal space.

Clinical Characteristics, Management Strategies, and Outcomes of Non-ST-Segment-Elevation Myocardial Infarction Patients With and Without Prior Coronary Artery Bypass Grafting

Background

There are limited data on the management strategies, temporal trends and clinical outcomes of patients who present with non–ST‐segment–elevation myocardial infarction and have a prior history of CABG.

Methods and Results

We identified 287 658 patients with non–ST‐segment–elevation myocardial infarction between 2010 and 2017 in the United Kingdom Myocardial Infarction National Audit Project database. Clinical and outcome data were analyzed by dividing into 2 groups by prior history of coronary artery bypass grafting (CABG): group 1, no prior CABG (n=262 362); and group 2, prior CABG (n=25 296). Patients in group 2 were older, had higher GRACE (Global Registry of Acute Coronary Events) risk scores and burden of comorbid illnesses. More patients underwent coronary angiography (69% versus 63%) and revascularization (53% versus 40%) in group 1 compared with group 2. Adjusted odds of receiving inpatient coronary angiogram (odds ratio [OR], 0.91; 95% CI, 0.88–0.95; P<0.001) and revascularization (OR, 0.73; 95% CI, 0.70–0.76; P<0.001) were lower in group 2 compared with group 1. Following multivariable logistic regression analyses, the OR of in‐hospital major adverse cardiovascular events (composite of inpatient death and reinfarction; OR, 0.97; 95% CI, 0.90–1.04; P=0.44), all‐cause mortality (OR, 0.96; 95% CI, 0.88–1.04; P=0.31), reinfarction (OR, 1.02; 95% CI, 0.89–1.17; P=0.78), and major bleeding (OR, 1.01; 95% CI, 0.90–1.11; P=0.98) were similar across groups. Lower adjusted risk of inpatient mortality (OR, 0.67; 95% CI, 0.46–0.98; P=0.04) but similar risk of bleeding (OR,1.07; CI, 0.79–1.44; P=0.68) and reinfarction (OR, 1.13; 95% CI, 0.81–1.57; P=0.47) were observed in group 2 patients who underwent percutaneous coronary intervention compared with those managed medically.

Conclusions

In this national cohort, patients with non–ST‐segment–elevation myocardial infarction with prior CABG had a higher risk profile, but similar risk‐adjusted in‐hospital adverse outcomes compared with patients without prior CABG. Patients with prior CABG who received percutaneous coronary intervention had lower in‐hospital mortality compared with those who received medical management.

Use of quantitative cardiovascular magnetic resonance myocardial perfusion mapping for characterization of ischemia in patients with left internal mammary coronary artery bypass grafts

BACKGROUND

Quantitative myocardial perfusion mapping using cardiovascular magnetic resonance (CMR) is validated for myocardial blood flow (MBF) estimation in native vessel coronary artery disease (CAD). Following coronary artery bypass graft (CABG) surgery, perfusion defects are often detected in territories supplied by the left internal mammary artery (LIMA) graft, but their interpretation and subsequent clinical management is variable.

METHODS

We assessed myocardial perfusion using quantitative CMR perfusion mapping in 38 patients with prior CABG surgery, all with angiographically-proven patent LIMA grafts to the left anterior descending coronary artery (LAD) and no prior infarction in the LAD territory. Factors potentially determining MBF in the LIMA-LAD myocardial territory, including the impact of delayed contrast arrival through the LIMA graft were evaluated.

RESULTS

Perfusion defects were reported on blinded visual analysis in the LIMA-LAD territory in 27 (71%) cases, despite LIMA graft patency and no LAD infarction. Native LAD chronic total occlusion (CTO) was a strong independent predictor of stress MBF (B = - 0.41, p = 0.014) and myocardial perfusion reserve (MPR) (B = - 0.56, p = 0.005), and was associated with reduced stress MBF in the basal (1.47 vs 2.07 ml/g/min; p = 0.002) but not the apical myocardial segments (1.52 vs 1.87 ml/g/min; p = 0.057). Extending the maximum arterial time delay incorporated in the quantitative perfusion algorithm, resulted only in a small increase (3.4%) of estimated stress MBF.

CONCLUSIONS

Perfusion defects are frequently detected in LIMA-LAD subtended territories post CABG despite LIMA patency. Although delayed contrast arrival through LIMA grafts causes a small underestimation of MBF, perfusion defects are likely to reflect true reductions in myocardial blood flow, largely due to proximal native LAD disease.

Coronary artery calcium progression after coronary artery bypass grafting surgery

OBJECTIVES

Accelerated atherosclerosis is a well-established phenomenon after coronary artery bypass grafting surgery (CABG). In this study, we analysed coronary artery calcium (CCS) progression after CABG.

METHODS

We retrospectively measured the CCS Agatston score (AS), volume score (VS) and mass score (MS) of 39 patients before and after CABG. The annualised CCS change and annualised CCS percent change of each coronary artery, coronary artery segments proximal and distal to anastomosis were analysed.

RESULTS

Mean age at the time of the surgery was 59.8±8.5 years. Follow-up period between the first and second CT scans was 6.7±2.8 (range, 1.1-12.8) years. Annualised CCS percent change (AS, VS and MS) of the coronary segments proximal-to-anastomosis did not differ from that of the non-grafted coronary arteries as follow: segments proximal-to-anastomosis: median (Q1-Q3) 12.8 (5.0-37.4), 13.7 (6.1-41.1) and 14.9 (5.4-53.7), left main coronary artery 12.6 (7.4-43.8), 22.0 (8.1-44.4) and 18.2 (7.3-57.4), non-grafted left circumflex artery: 13.5 (4.4-38.1), 10.5 (2.9-45.2) and 11.5 (7.1-47.9) and non-grafted right coronary artery: 31.4 (14.4-74.5), 25.2 (16.7-62.0) and 31.3 (23.8-85.6), respectively. Likewise, annualised percent change (AS, VS and MS) was similar between the native coronary arteries. Multivariate regression analysis showed that diabetes mellitus was the only predictor of annualised percent progression of the total CCS of >15% (HR, 8.12; 95% CI, 1.05 to 26.6; p=0.04).

CONCLUSION

The CCS post-CABG did not follow an accelerated progression process. Among coronary artery disease risk factors, diabetes mellitus is the only predictor of annualised CCS percent progression of >15% post-CABG.

Clinical outcomes of percutaneous coronary intervention for chronic total occlusion in prior coronary artery bypass grafting patients

OBJECTIVE

To compare the clinical characteristics and outcomes in patients with stable angina who have undergone chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in native arteries with or without prior coronary artery bypass grafting (CABG) surgery in a national cohort.

BACKGROUND

There are limited data on outcomes of patients presenting with stable angina undergoing CTO PCI with previous CABG.

METHODS

We identified 20,081 patients with stable angina who underwent CTO PCI between 2007-2014 in the British Cardiovascular Intervention Society database. Clinical, demographical, procedural and outcome data were analyzed in two groups; group 1-CTO PCI in native arteries without prior CABG (n = 16,848), group 2-CTO PCI in native arteries with prior CABG (n = 3,233).

RESULTS

Patients in group 2 were older, had more comorbidities and higher prevalence of severe left ventricular systolic dysfunction. Following multivariable analysis, no significant difference in mortality was observed during index hospital admission (OR:1.33, CI 0.64-2.78, p = .44), at 30-days (OR: 1.28, CI 0.79-2.06, p = .31) and 1 year (OR:1.02, CI 0.87-1.29, p = .87). Odds of in-hospital major adverse cardiovascular events (MACE) (OR:1.01, CI 0.69-1.49, p = .95) and procedural complications (OR:1.02, CI 0.88-1.18, p = .81) were similar between two groups but procedural success rate was lower in group 2 (OR: 0.34, CI 0.31-0.39, p < .001). The adjusted risk of target vessel revascularization (TVR) remained similar between the two groups at 30-days (OR:0.68, CI 0.40-1.16, P-0.16) and at 1 year (OR:1.01, CI 0.83-1.22, P-0.95).

CONCLUSION

Patients with prior CABG presenting with stable angina and treated with CTO PCI in native arteries had more co-morbid illnesses but once these differences were adjusted for, prior CABG did not independently confer additional risk of mortality, MACE or TVR.

Factors Influencing Stent Failure in Chronic Total Occlusion Coronary Intervention

Stent failure remains one of the greatest challenges for interventional cardiologists. Despite the evolution to superior second- and third-generation drug-eluting stent designs, increasing use of intracoronary imaging and the adoption of more potent antiplatelet regimens, registries continue to demonstrate a prevalence of stent failure or target lesion revascularisation of 15-20%. Predisposition to stent failure is consistent across both chronic total occlusion (CTO) and non-CTO populations and includes patient-, lesion- and procedure-related factors. However, histological and pathophysiological properties specific to CTOs, alongside complex strategies to treat these lesions, may potentially render percutaneous coronary interventions in this cohort more vulnerable to failure. Prevention requires recognition and mitigation of the precipitants of stent failure, optimisation of interventional techniques, including image-guided precision percutaneous coronary intervention, and aggressive modification of a patient's cardiovascular risk factors. Management of stent failure in the CTO population is technically challenging and itself begets recurrence. We aim to provide a comprehensive review of factors influencing stent failure in the CTO population and strategies to attenuate these.

Acute coronary syndrome due to native coronary occlusion proximal to a patent bypass graft: a case report

Background

Primary percutaneous coronary intervention (PCI) for acute coronary syndrome has significantly contributed to improvements in overall outcomes. However, clinical challenges exist when performing urgent PCI for patients with a history of coronary artery bypass grafting (CABG).

Case summary

An 83-year-old man with a history of CABG presented with an inferior ST-elevation myocardial infarction (STEMI). Emergent coronary angiography showed an occlusion of the right coronary artery that had been previously grafted with the right gastroepiploic artery. Primary PCI for the native coronary artery was performed on the assumption that the bypass graft had been occluded. We were unable to attain angiographic antegrade flow after balloon angioplasty, and intravascular ultrasound revealed a ruptured plaque with a thrombus proximally and a patent bypass graft with complete recanalization distally. These findings suggested that the plaque rupture with resultant thrombus formation proximal to the anastomosis eventually overlay the patent bypass graft. Subsequent stent implantation covering only the culprit site with a residual stenosis proximal to the anastomosis was performed, resulting in good patency of both the native coronary artery and bypass graft for more than 3 years.

Discussion

This is the first documented case of a patient with STEMI due to proximal native coronary artery occlusion with a thrombus overlying a patent bypass graft. Intravascular ultrasound was helpful to recognize the distal patency and guide optimal stent implantation. This case illustrates the complexity of treating a patient with a history of CABG and the importance of a multifaceted approach in such an urgent situation.

Coronary Artery Bypass: Review of Surgical Techniques and Impact on Long-Term Revascularization Outcomes

Coronary revascularization for multivessel disease remains a common and costly source of hospitalizations in the United States. Surgical techniques influence outcomes for coronary bypass and also affect the need for percutaneous coronary intervention in the future. As more radial access has been used for coronary angiography, consideration for use of the radial artery as a surgical conduit remains unclear. Saphenous vein grafts are commonly used for coronary bypass, however long-term patency remains suboptimal, and is also associated with a higher risk of adverse events with percutaneous coronary intervention. Thus, understanding the interplay between coronary bypass techniques and percutaneous coronary intervention has become increasingly important.

The Canadian Contribution to Science, Techniques, Technology, and Education in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions are considered the most complex coronary lesions in interventional cardiology. This article reviews the Canadian clinical and academic contributions to this field, including innovative procedural techniques, teaching and proctoring, clinical research, and the development of novel tools and therapies.

Clinical Characteristics, Management Strategies and Outcomes of Acute Myocardial Infarction Patients With Prior Coronary Artery Bypass Grafting

OBJECTIVE

To investigate the management strategies, temporal trends, and clinical outcomes of patients with a history of coronary artery bypass graft (CABG) surgery and presenting with acute myocardial infarction (MI).

PATIENTS AND METHODS

We undertook a retrospective cohort study using the National Inpatient Sample database from the United States (January 2004-September 2015), identified all inpatient MI admissions (7,250,768 records) and stratified according to history of CABG (group 1, CABG-naive [94%]; group 2, prior CABG [6%]).

RESULTS

Patients in group 2 were older, less likely to be female, had more comorbidities, and were more likely to present with non-ST-elevation myocardial infarction compared with group 1. More patients underwent coronary angiography (68% vs 48%) and percutaneous coronary intervention (PCI) (44% vs 26%) in group 1 compared with group 2. Following multivariable logistic regression analyses, the adjusted odd ratio (OR) of in-hospital major adverse cardiovascular and cerebrovascular events (OR, 0.98; 95% CI, 0.95 to 1.005; P=.11), all-cause mortality (OR, 1; 95% CI, 0.98 to 1.04; P=.6) and major bleeding (OR, 0.99; 95% CI, 0.94 to 1.03; P=.54) were similar to group 1. Lower adjusted odds of in-hospital major adverse cardiovascular and cerebrovascular events (OR, 0.64; 95% CI, 0.57 to 0.72; P<.001), all-cause mortality (OR, 0.45; 95% CI, 0.38 to 0.53; P<.001), and acute ischemic stroke (OR, 0.71; 95% CI, 0.59 to 0.86; P<.001) were observed in group 2 patients who underwent PCI compared with those managed medically without any increased risk of major bleeding (OR, 1.08; 95% CI, 0.94 to 1.23; P=.26).

CONCLUSIONS

In this national cohort, MI patients with prior-CABG had a higher risk profile, but similar in-hospital adverse outcomes compared with CABG-naive patients. Prior-CABG patients who received PCI had better in-hospital clinical outcomes compared to those who received medical management.

Retrograde recanalization of native right coronary artery chronic total occlusion (CTO) through left coronary artery CTO after bypass graft failure: A case report

RATIONALE

With the development and standardization of modern chronic total occlusions (CTOs) recanalization technique, percutaneous coronary intervention has become a promising treatment alternative to surgery after bypass graft failure. Treatment of a native coronary CTO lesion is preferable to treatment of a saphenous vein graft (SVG) CTO supplying the same territory; however, technical expertise is required.

PATIENT CONCERNS

This is a 69-year-old male with prior history of coronary artery bypass grafting presented with severe dyspnea at mild exertion (NYHA III) of 2 months duration.

DIAGNOSIS

The patient was diagnosed as heart failure caused by ischemia after SVG failure (SVG to right coronary artery) according to electrocardiogram, plasma N-terminal pro-B-type natriuretic peptide levels, and coronary angiogram.

INTERVENTIONS

We recanalized native right coronary artery CTO by retrograde approach using septal collaterals by surfing technique after recanalization of totally occluded left coronary artery.

OUTCOMES

Dyspnea was relieved at discharge. At 6-month follow-up, the patient had no recurrence of dyspnea.

LESSONS

In case of SVG failure, percutaneous coronary intervention of native vessel should be considered as a treatment option. Retrograde approach through native vessel is safe but has requirements for operators' volume, skill, and experience.

Predictors for New Native-Vessel Occlusion in Patients with Prior Coronary Bypass Surgery: A Single-Center Retrospective Research

Objectives

Chronic total occlusion (CTO) is prevalent in patients with prior coronary artery bypass grafting (CABG). However, data available concerning the prevalence of new-onset CTO of native vessels in patients with prior CABG is limited. Therefore, the objective of the study is to determine predictors for new native-vessel occlusion in patients with prior coronary bypass surgery.

Methods

354 patients with prior CABG receiving follow-up angiography are selected and analyzed in the present study, with clinical and angiographic variables being analyzed by logistic regression to determine the predictors of new native-vessel occlusion.

Results

The overall new occlusion rate was 35.59%, with multiple CTOs (42.06%) being the most prevalent (LAD 24.60% and RCA 18.25%, respectively). Additionally, current smoking (OR: 2.67; 95% CI: 2.60 to 2.74; p=0.01), reduced ejection fraction (OR: 1.76; 95% CI: 1.04 to 2.97; p=0.04), severe stenosis (OR: 3.65; 95% CI: 2.55 to 5.24; p=0.01), and diabetes mellitus (OR: 1.86; 95% CI: 1.34 to 2.97; p=0.04) serve as the independent predictors for new native-vessel occlusion.

Conclusion

As to high incidence of postoperative CTO, appropriate revascularization strategies and postoperative management should be taken into careful consideration.

Native Coronary Disease Progression Post Coronary Artery Bypass Grafting

BACKGROUND

It remains unclear if graft type impacts native disease progression in the target coronary artery post coronary artery bypass grafting (CABG).

METHODS

Patients who underwent repeat angiograms at least 6 months post CABG with ≥1 arterial graft were included. Pre/post CABG angiograms were examined by 2 experienced readers. Progression was defined as new stenosis of ≥50% in a previously normal coronary, an increase in previous stenosis of ≥20%, or a new occlusion. Primary outcome was the occurrence of native disease progression in bypassed vessels. Secondary outcomes included complete occlusion, left main (LM) and distal disease progression. Cox-proportional hazard regression models were used for time-to-event outcomes.

RESULTS

Study population included 98 patients comprising 263 grafts (143 arterial/120 venous grafts). Median time from surgery to catheterization was 559 days (Interquartile Range 374,910).Ninety-one target vessels showed progression (34.6%) with 75 to complete occlusion (28.5%). Progression was not associated with graft choice (HR 0.74(0.49,1.13) p = 0.163),but was significantly associated with age(p = 0.034),previous PCI(p = 0.002),ACE inhibitor (ACEi) use(p < 0.001),CAD severity (p < 0.001),CCS class III/IV(p = 0.016) and NYHA class III/IV(p < 0.001). Progression to occlusion was significantly associated with SVG (p = 0.019), as well as previous percutaneous coronary intervention (p = 0.007) and ACEi use (p < 0.001). LM disease progression was significantly associated with peripheral vascular disease (HR 5.44(1.92, 15.46), p = 0.001), and not affected by graft type (p = 0.754).

CONCLUSIONS

Native CAD progression in non-LM coronaries is multifactorial, while SVG use was only associated with occlusion of non-LM coronaries. The implications of this study warrant consideration for increased arterial grafting in CABG patients, while the negative associations of previous PCI and ACEi use carry important clinical implications, which require further investigation.

Animal chronic total occlusion models: A review of the current literature and future goals

Coronary chronic total occlusions (CTOs) are commonly found in patients undergoing coronary angiography and is associated with poorer prognosis than in those patients with other forms of stable coronary artery disease. As such, with an increasing appreciation of this clinical entity, there is a need to identify, firstly the pathophysiological process driving its formation, as well as new percutaneous strategies for revascularisation with long term durability and improved outcomes. An appropriate, reliable and reproducible animal model is vital for both of these objectives. We review the prevalence of spontaneous collaterals in different species, as well as review the current literature with respect to animal models of CTOs, and compare and contrast the advantages and disadvantages of these differing models. Whilst both extrinsic compression models and endoluminal procedures may create situations analogous to a CTO in a human, the ideal animal model of a CTO will include an occluded artery, functional collaterals and a viable myocardium. This would allow study of the process driving collateral formation and arteriogenesis as well as percutaneous intervention strategies for both acute and long term benefits.

Should functional assessment of lesion severity be used to guide coronary bypass?

PURPOSE OF REVIEW

The purpose of this article is to investigate the potential role of fractional flow reserve (FFR) to guide surgical revascularization.

RECENT FINDINGS

Coronary artery bypass is planned and executed primarily based on angiographic coronary anatomy. FFR is the most well-established tool for functional assessment of coronary lesions. Randomized trials have demonstrated the benefit of FFR-guided percutaneous coronary intervention (PCI) to determine the ischemic burden of intermediate lesions. Surgically, FFR is predominantly used to determine the functional severity of intermediate lesions of the left anterior descending (LAD) coronary artery to establish candidacy for multivessel coronary bypass. The broader use of FFR will likely downgrade a proportion of coronary lesions, which may alter the overall management plan. Whether this will improve clinical outcomes remains to be seen. Importantly, bypass of functionally nonsignificant lesions predicts graft failure. However, graft failure in the context of sufficient native coronary flow may not impact negatively on clinical outcome. Thus, at this time, there are insufficient data to support the wider use of FFR to guide surgical grafting of non-LAD targets. It remains to be seen whether FFR can be used to optimize the use of arterial grafts or to guide complex revascularization strategies such as hybrid coronary revascularization.

SUMMARY

FFR has become an invaluable tool for decision making for PCI in patients with stable ischemic heart disease. Beyond its use to assess an intermediate LAD lesion to establish candidacy for coronary bypass, at present there are insufficient data to support its wider use to guide surgical revascularization.