Clinical outcomes following stent implantation in internal mammary artery 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.

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.

Graftmaster savior: Injury to a patent LIMA during pericardiectomy, when a covered stent came to the rescue

A 71-year-old male with multivessel coronary artery disease who underwent bypass with saphenous vein grafts to a Marginal branch and distal RCA and LIMA to LAD in 1988, DM II, atrial fibrillation on Coumadin, TIA, obstructive sleep apnea and pulmonary hypertension was referred to our institution after extensive dyspnea evaluation with a diagnosis of constrictive pericarditis for pericardiectomy. He had normal left ventricular function, moderate mitral and tricuspid regurgitation. Coronary angiography revealed ostial LAD CTO, patent LIMA to mid LAD, second Marginal branch CTO with left-to-left collaterals and mid RCA CTO with left-to-right collaterals. Vein grafts to the Marginal branch and distal RCA were occluded. The pericardium was heavily calcified on CT of the chest. The LIMA was inadvertently injured leading to acute STEMI and ventricular fibrillation arrest treated with defibrillation once. Surgical repair was unsuccessful. A Graftmaster covered stent was successful deployed with restoration of TIMI III flow to the LAD territory. Pericardiectomy was completed via both the median resternotomy and left thoracotomy. Triple therapy with Aspirin, Clopidogrel, and Coumadin was initiated and maintained for 3 months without hemorrhagic or thrombotic complications. He has continued to do well in follow-up on Clopidogrel and Coumadin.

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.

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.

Successful angioplasty and stenting of bilateral internal mammary artery grafts from the left radial approach. Case report and review of the literature

We describe a case of successful percutaneous transluminal coronary angioplasty and stenting from the left radial approach in a patient with effort angina due to two tight stenoses at the distal anastomosis site of the internal mammary artery grafts. The left radial approach has several advantages compared with the conventional femoral approach: a lower rate of vascular complications and an easier vascular access to the left internal mammary artery graft. The distance from the access site to the origin of the artery is shorter and involves less angulation than the femoral approach. The radial approach is not only safe but it enables faster patient mobilisation and seems also useful in reducing management costs with a hospital stay that can be reduced to 6 h in low-risk cases.

Long drug-eluting stent implantation for a diffusely diseased right internal mammary artery

The frequent use of the internal mammary artery as a bypass graft has brought about an increasing need for angioplasty to treat stenotic arterial grafts. Percutaneous interventions of internal mammary artery grafts by balloon angioplasty or stenting with bare-metal stents have been described in the past. However, implantation of bare-metal stents was associated with high rates of restenosis. The introduction of drug-eluting stents for the treatment of diseased native coronary vessels has been associated with a reduced need for repeat intervention compared with bare-metal stents for both low-risk lesions and high-risk, complex lesions, including the 'long lesion' subset. We describe a case of long drug-eluting stent implantation for a diffusely diseased right internal mammary artery.

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

Drug-eluting stents (DESs) decrease the need for repeat revascularization in native coronary arteries and vein grafts. This study examined the safety and efficacy of DESs for the treatment of lesions in the internal mammary artery (IMA) conduits and compared the outcomes with those from bare metal stents (BMSs). Records of 69 consecutive patients who underwent stenting of the IMA from 2001 to 2004 were reviewed and analyzed. Of these, 30 patients were treated with DESs (sirolimus- or paclitaxel-eluting stents) and 39 patients with BMSs. In-hospital and 6-month clinical outcomes were recorded and compared. Baseline characteristics were comparable between the 2 groups. Lesion location and characteristics were also similar, except for a trend toward longer stent lengths in the DES group (DES 20.2 +/- 7.7 mm vs BMS 14.8 +/- 3.5 mm, p = 0.255). There was no late thrombosis in either group. There were no significant differences in in-hospital and 1- and 6-month outcomes between the 2 groups, including target lesion revascularization with DESs (DESs 3.33% vs BMSs 10%, p = 0.38). In conclusion, DES implantation into IMAs appears safe and is associated with low rates of recurrences. These results may support expansion of use of DESs for the management of IMA stenotic lesions.

Rotational atherectomy in the distal left anterior descending coronary artery through an internal mammary artery graft

We report the case of a 53-year-old white man who began complaining of dyspnoea and angina 19 months after coronary artery bypass graft surgery. Coronary angiography revealed the presence of a long and critical stenosis in the native left anterior descending coronary artery, shortly after distal anastomosis of the left internal mammary artery. After failed predilatations with standard or cutting balloons, we successfully used the rotablator system, which allowed us to implant a bare-metal stent in the native left anterior descending coronary artery. However, stent deployment caused long linear graft dissection, which was reduced by drug-eluting stent implantation in the proximal and distal segments of the left internal mammary artery.