A randomized, controlled trial of saphenous vein graft intervention with a filter-based distal embolic protection device: TRAP trial

Single-Centre Registry Analysis of Patients Who Underwent Percutaneous Coronary Intervention on Their Coronary Bypass Grafts

Background

The study assessed the outcomes of patients undergoing percutaneous coronary intervention (PCI) to bypass grafts, focusing on all-cause mortality and target vessel failure (TVF) rates.

Methods

A single-centre registry analysis included 364 patients who underwent PCI on coronary bypass grafts between 2008 and 2019. The study analyzed all-cause mortality and TVF, which encompassed target lesion revascularization, target vessel revascularization, and medically treated occluded target graft post-PCI.

Results

The median age of the patients was 71 years (interquartile range: [IQR] 65-78), with 82.1% being male. Most patients (94.8%) received PCI on saphenous vein grafts, and the median graft age was 13.0 years (IQR: 8.4-17.6). Drug-eluting stents were used more frequently (54.4%) than bare-metal stents (45.6%), with a median stent diameter of 3.5 mm (IQR: 3-4) and length of 19 mm (IQR: 18-28). Outcome differences were not significant for PCI sites (aorto-ostial, graft body, anastomosis), use of drug-eluting stents, or use of protection devices. The 1-year mortality rate was 3.3%, whereas the combined rate of TVF or death was 20.3%. After 5 years, the mortality rate increased to 14.9%, and the combined TVF or death rate rose to 40.3%. Multivariable analyses revealed that chronic kidney disease was independently associated with mortality (hazard ratio [HR] 1.74, 95% confidence interval [CI] 1.16-2.61, P = 0.007), whereas hypertension (HR 2.42, 95% CI 1.32-4.42, P = 0.004) and increased stent length (HR 1.01, 95% CI 1.00-1.02, P = 0.007) were independently associated with the TVF-or-mortality outcome.

Conclusions

Patients undergoing PCI to bypass grafts experience considerable adverse outcomes over a 5-year period, highlighting the need for further strategies in managing this high-risk population.

Saphenous Vein Graft Failure: Current Challenges and a Review of the Contemporary Percutaneous Options for Management

The use of saphenous vein grafts (SVGs) in the surgical management of obstructive coronary artery disease remains high despite a growing understanding of their limitations in longevity. In contemporary practice, approximately 95% of patients receive one SVG in addition to a left internal mammary artery (LIMA) graft. The precise patency rates for SVGs vary widely in the literature, with estimates of up to 61% failure rate at greater than 10 years of follow-up. SVGs are known to progressively degenerate over time and, even if they remain patent, demonstrate marked accelerated atherosclerosis. Multiple studies have demonstrated a marked acceleration of atherosclerosis in bypassed native coronary arteries compared to non-bypassed arteries, which predisposes to a high number of native chronic total occlusions (CTOs) and subsequent procedural challenges when managing graft failure. Patients with failing SVGs frequently require revascularisation to previously grafted territories, with estimates of 13% of CABG patients requiring an additional revascularisation procedure within 10 years. Redo CABG confers a significantly higher risk of in-hospital mortality and, as such, percutaneous coronary intervention (PCI) has become the favoured strategy for revascularisation in SVG failure. Percutaneous treatment of a degenerative SVG provides unique challenges secondary to a tendency for frequent superimposed thrombi on critical graft stenoses, friable lesions with marked potential for distal embolization and subsequent no-reflow phenomena, and high rates of peri-procedural myocardial infarction (MI). Furthermore, the rates of restenosis within SVG stents are disproportionately higher than native vessel PCI despite the advances in drug-eluting stent (DES) technology. The alternative to SVG PCI in failed grafts is PCI to the native vessel, 'replacing' the grafts and restoring patency within the previously grafted coronary artery, with or without occluding the donor graft. This strategy has additional challenges to de novo coronary artery PCI, however, due to the high burden of complex atherosclerotic lesion morphology, extensive coronary calcification, and the high incidence of CTO. Large patient cohort studies have reported worse short- and long-term outcomes with SVG PCI compared to native vessel PCI. The PROCTOR trial is a large and randomised control trial aimed at assessing the superiority of native vessel PCI versus vein graft PCI in patients with prior CABG awaiting results. This review article will explore the complexities of SVG failure and assess the contemporary evidence in guiding optimum percutaneous interventional strategy.

Outcomes Following Percutaneous Coronary Intervention in Saphenous Vein Grafts With and Without Embolic Protection Devices: A Systematic Review and Meta-Analysis

Objective

This study aimed to review studies comparing outcomes following percutaneous coronary intervention (PCI) in saphenous vein grafts (SVG) with and without embolic protection devices (EPD).

Methods

Databases including PubMed Central, Cochrane Library, EMBASE, CINAHL, MEDLINE, Google Scholar, ScienceDirect, and Scopus were searched from January 1964 to April 2021. We used the Cochrane risk of bias tool and the Newcastle Ottawa scale to assess the quality of published studies based on study design. From the results, we carried out a meta-analysis with a random-effects model and reported pooled odds ratio (OR) with 95% CI.

Results

In total, 11 studies were analyzed that included 79,009 total participants. EPD use had significantly lower odds of mortality (pooled OR = 0.69; 95% CI: 0.5–0.94). There was no significant difference in terms of major adverse cardiovascular events (MACE) (pooled OR = 0.83; 95% CI: 0.67–1.03), target vessel revascularization (pooled OR = 1; 95% CI: 0.95–1.05), periprocedural (pooled OR = 1.12; 95% CI: 0.65–1.9) and late myocardial infarction (MI) (pooled OR = 0.79; 95% CI: 0.55–1.14) with or without EPD for PCI in SVG patients.

Conclusion

Although not statistically beneficial for MACE, target vessel revascularization, periprocedural, and late MI, EPD use does appear to significantly reduce mortality for the patients undergoing PCI in SVG. Clinicians might consider using EPD for such patients to reduce the burden of post-procedural morbidity and mortality.

Saphenous Vein Graft Failure: From Pathophysiology to Prevention and Treatment Strategies

Saphenous vein grafts (SVGs) remain the most frequently used conduits in coronary artery bypass graft surgery (CABG). Despite advances in surgical techniques and pharmacotherapy, SVG failure rates remain high, often leading to repeat coronary revascularization. The no-touch SVG harvesting technique (minimal graft manipulation with preservation of vasa vasorum and nerves) reduces the risk of SVG failure, whereas the effect of the off-pump technique on SVG patency remains unclear. Use of buffered storage solutions, intraoperative graft flow measurement, careful selection of the target vessels, and physiological assessment of the native coronary circulation before CABG may also reduce the incidence of SVG failure. Perioperative aspirin and high-intensity statin administration are the cornerstones of secondary prevention after CABG. Dual antiplatelet therapy is recommended for off-pump CABG and in patients with a recent acute coronary syndrome. Intermediate (30%-60%) SVG stenoses often progress rapidly. Stenting of intermediate SVG stenoses failed to improve outcomes; hence, treatment focuses on strict control of coronary artery disease risk factors. Redo CABG is associated with higher perioperative mortality compared with percutaneous coronary intervention (PCI); hence, the latter is preferred for most patients requiring repeat revascularization after CABG. SVG PCI is limited by high rates of no-reflow and a high incidence of restenosis during follow-up. Drug-eluting and bare metal stents provide similar long-term outcomes in SVG PCI. Embolic protection devices reduce no-reflow and should be used when feasible. PCI of the corresponding native coronary artery is associated with better short- and long-term outcomes and is preferred over SVG PCI, if technically feasible.

Safety and Efficacy of Embolic Protection Devices in Saphenous Vein Graft Interventions: A Propensity Score Analysis-Multicenter SVG PCI PROTECTA Study

Background: Evidence concerning the efficacy of the embolic protection devices (EPDs) in saphenous vein graft (SVG) percutaneous coronary intervention (PCI) is sparse. The study was designed to compare major cardiovascular events of all-comer population of SVG PCI with and without EPDs at one year of follow-up. Methods and results: A multi-center registry comparing PCI with and without EPDs in consecutive patients undergoing PCI of SVG. The group comprised 792 patients, among which 266 (33.6%) had myocardial infarction (MI). The primary composite endpoint was major adverse cardiac and cerebrovascular event (MACCE) defined as death, MI, target vessel revascularization (TVR), and stroke assessed at one year. After propensity score analysis, there were no differences in MACCE (21.9% vs. 23.9%; HR 0.91, 95% CI 0.57–1.45, p = 0.681, respectively) nor in secondary endpoints of death, MI, TVR, target lesion revascularization (TLR) and stroke at one year in EPDs PCI group vs. no-EPDs PCI group. Similarly, there were no differences between groups in the study endpoints at 30 days follow-up. Conclusions: There were no clinical benefit for routine use of EPDs during SVG PCI in short and long-term follow-up. Further studies are warranted to explore the effect of individual types of EPDs on clinical outcomes.

Predicting risk of cardiovascular events 1 to 3 years post-myocardial infarction using a global registry

BACKGROUND

Risk prediction tools are lacking for patients with stable disease some years after myocardial infarction (MI).

HYPOTHESIS

A practical long-term cardiovascular risk index can be developed.

METHODS

The long-Term rIsk, Clinical manaGement and healthcare Resource utilization of stable coronary artery dISease in post-myocardial infarction patients prospective global registry enrolled patients 1 to 3 years post-MI (369 centers; 25 countries), all with ≥1 risk factor (age ≥65 years, diabetes mellitus requiring medication, second prior MI, multivessel coronary artery disease, or chronic non-end-stage kidney disease [CKD]). Self-reported health was assessed with EuroQoL-5 dimensions. Multivariable Poisson regression models were used to determine key predictors of the primary composite outcome (MI, unstable angina with urgent revascularization [UA], stroke, or all-cause death) over 2 years.

RESULTS

The primary outcome occurred in 621 (6.9%) of 9027 eligible patients: death 295 (3.3%), MI 195 (2.2%), UA 103 (1.1%), and stroke 58 (0.6%). All events accrued linearly. In a multivariable model, 11 significant predictors of primary outcome (age ≥65 years, diabetes, second prior MI, CKD, history of major bleed, peripheral arterial disease, heart failure, cardiovascular hospitalization (prior 6 months), medical management (index MI), on diuretic, and poor self-reported health) were identified and combined into a user-friendly risk index. Compared with lowest-risk patients, those in the top 16% had a rate ratio of 6.9 for the primary composite, and 18.7 for all-cause death (overall c-statistic; 0.686, and 0.768, respectively). External validation was performed using the Australian Cooperative National Registry of Acute Coronary Care, Guideline Adherence and Clinical Events registry (c-statistic; 0.748, and 0.849, respectively).

CONCLUSIONS

In patients >1-year post-MI, recurrent cardiovascular events and deaths accrue linearly. A simple risk index can stratify patients, potentially helping to guide management.

Contemporary Use of Embolic Protection Devices During Saphenous Vein Graft Intervention

BACKGROUND

Guidelines recommend use of embolic protection devices during percutaneous coronary intervention of saphenous vein grafts, but the use of these devices in contemporary practice is unclear. We thus sought to evaluate the patient characteristics and clinical outcomes associated with embolic protection device use during contemporary saphenous vein graft percutaneous coronary intervention.

METHODS AND RESULTS

We identified patients undergoing isolated saphenous vein graft percutaneous coronary intervention in the Veterans Affairs Healthcare System from January 2008 to June 2017. Patient and procedural characteristics associated with embolic protection device use were assessed, as well as unmeasured site variation. A propensity-matched cohort was constructed to compare outcomes at 30 days, including unsuccessful intervention, periprocedural myocardial infarction, and death. We identified 7266 vein graft interventions, and embolic protection was used in 37.9% of cases, with a significant decline over time ( P=0.001) that was most pronounced from 2014 to 2017 ( P<0.001). There was significant institutional variation in the use of embolic protection, with a 15.50 (95% credible interval, 9.21-29.71)-fold difference in odds of device use by changing facilities independent of patient or procedural factors. Use of embolic protection was associated with reduced risk of unsuccessful intervention (odds ratio, 0.27; 95% credible interval, 0.17-0.42) and 30-day mortality (odds ratio, 0.56; 95% credible interval, 0.36-0.87).

CONCLUSIONS

Use of embolic protection is decreasing with time and occurs in less than half of vein graft interventions. There is significant site variation in the use of embolic protection independent of patient characteristics, suggesting opportunities for the development of uniform practices to improve outcomes among those undergoing saphenous vein graft percutaneous coronary intervention.

Three-Year Outcomes Associated With Embolic Protection in Saphenous Vein Graft Intervention

Background—

Information is limited on contemporary use and outcomes of embolic protection devices (EPDs) in saphenous vein graft interventions.

Methods and Results—

We formed a longitudinal cohort (2005–2009; n=49 325) by linking National Cardiovascular Data Registry CathPCI Registry to Medicare claims to examine the association between EPD use and both procedural and long-term outcomes among seniors (65+ years), adjusting for clinical factors using propensity and instrumental variable methodologies. Prespecified high-risk subgroups included acute coronary syndrome and de novo or graft body lesions. EPDs were used in 21.2% of saphenous vein grafts (median age, 75; 23% women) and were more common in acute coronary syndrome (versus non–acute coronary syndrome; 22% versus 19%), de novo (versus restenotic; 22% versus 14%), and graft body lesions (versus aortic and distal anastomosis; 24% versus 20% versus 8%, respectively). EPDs were associated with a slightly higher incidence of procedural complications, including no reflow (3.9% versus 2.8%; P <0.001), vessel dissection (1.3% versus 1.1%; P =0.05), perforation (0.7% versus 0.4%; P =0.001), and periprocedural myocardial infarction (2.8% versus 1.8%; P <0.001). By 3 years, death, myocardial infarction, and repeat revascularization occurred in 25%, 15%, and 30% of cases, respectively. EPD use was associated with a similar adjusted risk of death (propensity score–matched hazard ratio, 0.96; 95% confidence interval, 0.91–1.02), myocardial infarction (propensity score–matched hazard ratio, 1.00; 95% confidence interval, 0.93–1.09), and repeat revascularization (propensity score–matched hazard ratio, 1.02; 95% confidence interval, 0.96–1.08) in the overall cohort and high-risk subgroups.

Conclusions—

In this contemporary cohort, EPDs were used more commonly among patients with high-risk clinical indications, yet there was no evidence of improved acute- or long-term outcomes. Further prospective studies are needed to support routine EPD use.

Secondary revascularization after CABG surgery

CABG surgery is an effective way to improve symptoms and prognosis in patients with advanced coronary atherosclerotic disease. Despite multiple improvements in surgical technique and patient treatment, graft failure after CABG surgery occurs in a time-dependent fashion, particularly in the second decade after the intervention, in a substantial number of patients because of atherosclerotic progression and saphenous-vein graft (SVG) disease. Until 2010, repeat revascularization by either percutaneous coronary intervention (PCI) or surgical techniques was performed in these high-risk patients in the absence of specific recommendations in clinical practice guidelines, and within a culture of inadequate communication between cardiac surgeons and interventional cardiologists. Indeed, some of the specific technologies developed to reduce procedural risk, such as embolic protection devices for SVG interventions, are largely underused. Additionally, the implementation of secondary prevention, which reduces the need for reintervention in these patients, is still suboptimal. In this Review, graft failure after CABG surgery is examined as a clinical problem from the perspective of holistic patient management. Issues such as the substrate and epidemiology of graft failure, the choice of revascularization modality, the specific problems inherent in repeat CABG surgery and PCI, and the importance of secondary prevention are discussed.

Saphenous vein graft intervention

Saphenous vein grafts are commonly used conduits for surgical revascularization of coronary arteries but are associated with poor long-term patency rates. Percutaneous revascularization of saphenous vein grafts is associated with worse clinical outcomes including higher rates of in-stent restenosis, target vessel revascularization, myocardial infarction, and death compared with percutaneous coronary intervention of native coronary arteries. Use of embolic protection devices is a Class I indication according to the American College of Cardiology/American Heart Association guidelines to decrease the risk of distal embolization, no-reflow, and periprocedural myocardial infarction. Nonetheless, these devices are underused in clinical practice. Various pharmacological agents are available that may also reduce the risk of or mitigate the consequences of no-reflow. Covered stents do not decrease the rates of periprocedural myocardial infarction and restenosis. Most available evidence supports treatment with drug-eluting stents in this high-risk lesion subset to reduce angiographic and clinical restenosis, although large, randomized trials comparing drug-eluting stents and bare-metal stents are needed.

Proximal protection in recanalization of totally occluded saphenous vein grafts in acute coronary syndrome

Percutaneous treatment of old, degenerated saphenous vein grafts (SVG) is associated with a high likelihood of major adverse cardiac events. When an acute coronary syndrome (ACS) develops in a patient with old SVG, fresh thrombus may superimpose on an old, degenerative atheroma: a sudden increase in the athero-thrombotic burden ensues with consequent, frequent total occlusion of the lumen. In this scenario, transluminal recanalization of the graft is usually associated with the highest chance of distal embolization and no-reflow and positioning of an embolic protection device (EPD) is almost mandatory. However, distal EPD are difficult to place when the vessel is totally occluded and do not completely avoid distal embolization. We report two cases of totally occluded SVG in patients admitted for ACS that were recanalized with the aid of a proximal EPD system with angiographic and clinical success.