Comparison of outcomes between bare metal stents and drug-eluting stents for percutaneous revascularization of internal mammary grafts

Long-term outcomes of percutaneous revascularization for internal mammary artery-left anterior descending artery bypass failure

Despite the excellent long-term results of internal mammary artery (IMA)-left anterior descending (LAD) bypass, percutaneous revascularization of IMA is sometimes required for IMA-LAD bypass failure. However, its clinical outcomes have not been fully elucidated. The aim of this study was to investigate the long-term clinical outcomes, including target lesion revascularization (TLR) following contemporary percutaneous revascularization of failed IMA bypass graft. We examined data of 59 patients who had undergone percutaneous revascularization of IMA due to IMA-LAD bypass failure at nine hospitals. Patients with IMA graft used for Y-composite graft or sequential bypass graft were excluded. The incidence of TLR was primarily examined, whereas other clinical outcomes including cardiac death, myocardial infarction, and target vessel revascularization were also evaluated. Mean age of the enrolled patients was 67.4 ± 11.3 years, and 74.6% were men. Forty patients (67.8%) had anastomotic lesions, and 17 (28.8%) underwent revascularization within three months after bypass surgery. Procedural success was achieved in 55 (93.2%) patients. Stent implantation was performed in 13 patients (22.0%). During a median follow-up of 1401 days (interquartile range, 282-2521 days), TLR was required in six patients (8.5% at 1, 3, and 5 years). Patients who underwent percutaneous revascularization within 3 months after surgery tended to have a higher incidence of TLR. Clinical outcomes of IMA revascularization for IMA-LAD bypass failure were acceptable.

Drug-Eluting Stent Restenosis: Modern Approach to a Classic Challenge

In-stent restenosis (ISR) is a recognized complication following percutaneous coronary intervention in which the luminal diameter is narrowed through neointimal hyperplasia and vessel remodeling. Although rates of ISR have decreased in most recent years owing to newer generation drug-eluting stents, thinner struts, and better intravascular imaging modalities, ISR remains a prevalent dilemma that proves to be challenging to manage. Several factors have been proposed to contribute to ISR formation, including mechanical stent characteristics, technical factors during the coronary intervention, and biological aspects of drug-eluting stents. Presentation of ISR can range from asymptomatic to late myocardial infarction and could be difficult to differentiate from acute thrombus formation. No definite guidelines are present on the management of ISR. In this review, we will discuss the mechanisms underlying ISR and provide insight into patient-related and procedural risk factors contributing to ISR, in addition to highlighting common treatment approaches utilized in the management of ISR.

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.

Preventing graft restenosis after coronary artery bypass grafting with tissue-type plasminogen activator

Objective

To explore the feasibility and safety of using tissue-type plasminogen activator (t-PA) to prevent graft restenosis after coronary artery bypass grafting (CABG).

Methods

In this prospective observational study, 37 patients underwent CABG between June 2009 and May 2013. These patients were grouped according to the anti-coagulation strategy after surgery: t-PA (n = 12) and conventional treatments (n = 25). In the t-PA group, the patients received acetylsalicylic acid (ASA) and clopidogrel plus intravenous infusion of t-PA (0.25 mg/kg/day) starting at 24 h after surgery and that lasted for 3 days. In the conventional group, the patients received only ASA and clopidogrel. 64-row spiral computed tomographic coronary angiography was performed at 1 week, 1, and 3 months after surgery to evaluate the patency of the graft vessel.

Results

The mean stenosis severity of the saphenous vein grafts was lower in the t-PA group compared with the conventional group at 3 months after surgery (p < 0.05), but there was no significant difference at 1 week and 1 month (p > 0.05). The patency rate of the grafts was not significantly different between the two groups at 1 week, 1, and 3 months after surgery (p > 0.05).

Conclusion

Early application of t-PA after CABG was feasible and safe, and might help prevent early restenosis of SV grafts. Additional clinical randomized trials are necessary to address this issue.

Immediate and Long-Term Results of Drug-Eluting Stents in Mammary Artery Grafts

Percutaneous intervention of a coronary graft is the treatment of choice when the graft fails. The objective is to report the long-term results of drug-eluting stents (DES) in mammary artery grafts (MAG). Patients who had been treated with DES for MAG in 27 centers were selected. The baseline and procedural clinical data were included prospectively, and the follow-up was performed with the patients, families, and medical records. Two hundred and sixty-eight patients were included: age 65.5 ± 10.1 years, diabetes 47.8%, ejection fraction 55.5 ± 14.9%.

INDICATION

stable angina 28.4%, unstable angina 38.1%, non-ST-elevation myocardial infarction 21.6%, ST-elevation myocardial infarction 5.3%, and heart failure 6.7%; 1.19 ± 0.59 stents/patient were implanted measuring 18.8 ± 8.8 mm in length and 2.68 ± 0.35 mm in diameter. Rapamycin was used in 78 cases (29.1%), paclitaxel in 77 (28.7%), everolimus in 70 (26.1%), zotarolimus in 34 (12.7%), and biolimus in 9 (3.4%). All cases were successful except for 1 in which the patient died 30 minutes after the procedure. There were no other inhospital events. After a follow-up of 41 months (Q25: 23.7 to Q75: 57.8), 24 patients (9%) died of heart-related causes and 20 (7.5%) of noncardiac causes. Repeat revascularization was necessary in 31 cases, and in 1 additional patient, there was total occlusion, which was not treated. These 32 patients represented 11.9% of the total. In conclusion, the implantation of DES in MAG shows very high procedural success and also low long-term event rates.

Distal anastomotic lesions after coronary artery bypass surgery: incidence, pathogenesis, and treatment approach

Distal anastomotic lesions are the most common reason for venous and arterial graft failure. Redo coronary artery bypass surgery carries a higher risk for mortality and non-fatal myocardial infarction. Many operators therefore consider percutaneous coronary intervention as a good alternative for relieving angina symptoms in this subset of patients with anastomotic lesions. However, the best percutaneous method for treating these lesions is still controversial. Here we review reported data on the incidence, pathogenesis, and treatment of distal anastomotic lesions in both venous and arterial bypass grafts.

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.

Percutaneous Revascularization of Grafts versus Native Coronary Arteries in Postcoronary Artery Bypass Graft Patients

In patients with previous coronary artery bypass graft surgery, it is unknown whether better results may be obtained with percutaneous interventions of grafts versus native arteries. The clinical outcomes in 84 patients undergoing percutaneous interventions of either grafts (n = 31) or native arteries (n = 53) were compared. Procedural success rate was 95.3% (96.8% in the graft group vs 94.4% in the native group, P = .3). Mean follow-up was 19 ± 7 months. The incidence of major adverse events was 14.2% (12.9% vs 15.1% in the graft and native groups, respectively; P = .8), mortality rate was 3.5% (6.4% vs 1.8% in the graft and native groups, respectively; P = .3), and target-lesion revascularization was performed in 4.7% (6.4% vs 3.7% in the graft and native groups, respectively, P = .6). In conclusion, both graft or native percutaneous interventions were similar for immediate and midterm clinical outcomes. The relatively low risk need for target-lesion revascularization obtained with both strategies is encouraging.

Percutaneous revascularization of grafts versus native coronary arteries in postcoronary artery bypass graft patients

In patients with previous coronary artery bypass graft surgery, it is unknown whether better results may be obtained with percutaneous interventions of grafts versus native arteries. The clinical outcomes in 84 patients undergoing percutaneous interventions of either grafts (n = 31) or native arteries (n = 53) were compared. Procedural success rate was 95.3% (96.8% in the graft group vs 94.4% in the native group, P = .3). Mean follow-up was 19 +/- 7 months. The incidence of major adverse events was 14.2% (12.9% vs 15.1% in the graft and native groups, respectively; P = .8), mortality rate was 3.5% (6.4% vs 1.8% in the graft and native groups, respectively; P = .3), and target-lesion revascularization was performed in 4.7% (6.4% vs 3.7% in the graft and native groups, respectively, P = .6). In conclusion, both graft or native percutaneous interventions were similar for immediate and midterm clinical outcomes. The relatively low risk need for target-lesion revascularization obtained with both strategies is encouraging.

Drug-eluting stents for the percutaneous treatment of the anastomosis of the left internal mammary graft to left anterior descending artery

BACKGROUND

Data on the treatment of left internal mammary to left anterior descending artery (LIMA-to-LAD) anastomotic disease are scarce and not homogeneous. Both surgery and percutaneous interventions (PCI) have been attempted, but the most effective treatment has not yet been established. In particular, should PCI be performed, the role of stenting seems to be limited by less favorable results than in other subsets of lesions.

OBJECTIVE

To assess the clinical impact of drug-eluting stent (DES) use in this particular subset of lesions.

METHODS

We describe a cohort of patients treated with PCI on LIMA-to-LAD anastomoses, reporting acute 1-year clinical and angiographic outcomes. The clinical impact of DES use was evaluated as the requirement for target lesion revascularizations (TLR).

RESULTS

Fifty-six consecutive patients were evaluated. Acute procedural success was achieved in 52 patients (92.8%). Plain balloon angioplasty allowed acute procedural success in 15 patients (28.8%), whereas stenting was required in 37 patients (71.2%) with suboptimal results or to treat complications. Bare-metal stents (BMS) were used in 17 and DES in 20 patients, without differences in acute results. One-year clinical follow-up was available in 96.1% of patients. TLR were needed in 17.3% of patients. No significant differences were detected in TLR rates after treatment with BMS and DES (26.6% vs. 25%; P=0.99). Two late stent thromboses were observed after DES deployment.

CONCLUSION

PCI of the stenoses of LIMA-to-LAD anastomoses with DES did not provide any clinical improvement over BMS use in long-term outcomes; DES use was associated with some cases of late thrombosis.