Percutaneous revascularization of the internal mammary artery graft: short- and long-term outcomes

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.

The Association Between the Albumin-Bilirubin Score and Contrast-Associated Acute Kidney Injury in Patients Undergoing Elective Percutaneous Coronary Intervention

The albumin-bilirubin (ALBI) score is considered an effective and convenient scoring system for assessing liver function. We hypothesized that the ALBI score was predictive of contrast-associated acute kidney injury (CA-AKI) and long-term mortality in patients undergoing elective percutaneous coronary intervention (PCI). We retrospectively observed 5629 patients undergoing elective PCI. Contrast-associated acute kidney injury is defined as a 50% or 0.3 mg/dl increase in baseline serum creatinine levels within 48 h of contrast exposure. The incidence of CA-AKI was 6.2% (n = 350). After adjusting for potential confounding factors, multivariate analysis showed that the ALBI score was an independent predictor of CA-AKI (P = .002). A restricted cubic spline analysis confirmed approximately linear relationships between the ALBI score and risks of CA-AKI. Furthermore, at a median follow-up of 2.8 years, multivariate Cox regression analysis indicated that the ALBI score was an independent risk factor for long-term mortality (P < .001). The ALBI score was closely related to the occurrence of CA-AKI and long-term mortality in patients who underwent elective PCI. This score might be useful for risk stratification in high-risk patient groups to predict CA-AKI.

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.

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.

Late spontaneous internal thoracic artery graft dissection after coronary bypass grafting: a case report

Background

Internal thoracic artery (ITA) grafts are commonly used for coronary artery bypass grafting, with dissection to the graft being a rare occurrence. Herein, we describe a case of spontaneous ITA graft dissection occurring 11 years after grafting, with no clear precipitating incidence.

Case summary

The patient was a 61-year-old man who presented with a 3-month history of chest pain and dyspnoea. Dissection of the left internal thoracic artery (LITA) graft was observed on angiography, with a thrombolysis in the myocardial infarction (TIMI) grade 2 blood flow. Intravascular ultrasound confirmed an intimal tear in the proximal graft, with an intramural haematoma. In the absence of atherosclerotic changes, the dissection was treated directly using multiple drug-eluting stents to prevent further extension of the intramural haematoma proximally into the subclavian artery and distally to the anastomosis site. Post-procedural angiography revealed an enlarged true lumen of the LITA, shrinking of the intramural haematoma, and improvement in blood flow to a TIMI grade 3. Chest symptoms resolved immediately after the procedure, with the patient remaining asymptomatic over the 6-month period following the procedure.

Discussion

Dissection of the ITA graft can occur spontaneously long after the initial grafting. Intravascular ultrasound is useful for diagnosis. Ensuring adequate coverage of the edges of the dissection with stenting could prevent further extension of the intramural haematoma.

Successful percutaneous coronary intervention to the left anterior descending artery in-stent chronic total occlusion via the left internal mammary artery graft: a case report

Background

Percutaneous coronary intervention (PCI) via left internal mammary artery (LIMA) graft is technically challenging, requires special consideration due to association with potential complications and therefore, infrequently performed. Data on in-stent chronic total occlusion (CTO) PCI via the LIMA graft is even rarer.

Case summary

A 59-year-old male with a background history of coronary artery bypass graft surgery and previous PCI, presented with progressive chest pain on mild exertion, in the setting of a chronic coronary syndrome. Transradial coronary angiography revealed significant native three-vessel disease with CTO of right coronary, left anterior descending (LAD) and left circumflex arteries. Left internal mammary artery-LAD was widely patent. The previous LIMA-LAD stent at the anastomosis had a CTO with severe in-stent restenosis (ISR) at the distal end of the stent in the native LAD. The distal LAD was filled from bridging collaterals. Following discussion at the heart team meeting, he underwent successful complex PCI of LAD CTO via the LIMA graft at the site of ISR of previous LIMA-LAD anastomosis stent, which was finally treated with drug-coated balloon (DCB) angioplasty.

Discussion

Recurrent angina post-coronary revascularization can be very challenging to manage by medical therapy alone. Percutaneous intervention of complex coronary lesions in these patients requires experience and skill, especially when approaching lesions using the LIMA as a conduit. The use of DCB for ISR management is a well-known strategy; however, adequate lesion preparation is the key to satisfactory outcome.

Spontaneous Internal Mammary Artery Graft Dissection Triggered by Emotional Stress

Internal mammary artery graft dissection is a rare condition and is usually caused by iatrogenic complications or mechanical stress. We experienced a case of acute myocardial infarction due to spontaneous internal mammary artery graft dissection that was triggered by emotional stress and was successfully treated by percutaneous intervention using drug-eluting stents. (Level of Difficulty: Beginner.).

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.

Internal mammary artery graft failure: Clinical features, management, and long-term outcomes

Objective

Data on long-term outcomes after internal mammary artery (IMA) coronary graft failure are scarce. Our objective was to describe the clinical characteristics, management, and prognosis after angiographically confirmed IMA graft failure following coronary revascularization.

Methods

A three-hospital retrospective registry, observational and descriptive, with prospective follow-up of all consecutive cases of IMA graft failure between 2004 and 2014 was conducted. After treatment, clinical and procedural features were compared between those with and without cardiovascular events.

Results

Fifty-seven patients were included (89% male, mean age: 62 years, at surgery) in the registry. Most patients underwent an IMA angioplasty (percutaneous coronary intervention [PCI], 74%). In nine cases, the PCI failed at the graft level, and seven underwent a native vessel revascularization. Native vessel treatment was performed in 20% of the study subjects, all with stents. Finally, medical management was decided in three cases. Events after treatment for IMA graft failure were frequent (50.8%), during a median follow-up of 7.5 years. Acute presentation (hazard ratio_MACE = 1.35; 95% confidence interval (CI): 1.12–3.00, p < 0.01), age of the patient (hazard ratio_MACE = 1.85, 95% CI: 1.17–2.11, p < 0.01), presence of diabetes mellitus (hazard ratio_MACE = 2.75, 95% CI: 1.13–6.69, p = 0.02), and the management modality used (IMA-simple angioplasty VS IMA-stenting: hazard ratio_MACE = 5.5, 95% CI: 1.40–21.15, p = 0.01) displayed prognostic relevance on multivariate analysis. All-cause mortality occurred in 21.1% and presentation as infarction (hazard ratio_DEATH = 1.05, 95% CI: 1.01–2.17, p = 0.01), age (hazard ratio_DEATH = 9.08, 95% CI: 2.52–32.69, p < 0.01), and left ventricular ejection fraction (hazard ratio_DEATH = 3.68, 95% CI: 1.65–8.18, p < 0.01) were independent predictors of the same.

Conclusions

In this long-term registry, most patients presented with an acute condition (myocardial infarction, progressive angina) within 12 months after surgery. Acute presentation, age, diabetes mellitus, reduced left ventricular ejection fraction, IMA graft failure segment affected, and the management strategy were related with long-term prognosis.

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.

Complete stent fracture 1 year after LIMA PCI due to LIMA and subclavian artery dissection

Stent platforms are prone to fracture while incidental data are demonstrating a potential unfavorable outcome. Predisposing factors usually involve long lesions and tortuous vessels requiring more than one stent. This issue is magnified when it involves a periprocedural iatrogenic left internal mammary artery (LIMA) and subclavian artery dissection. In such complex clinical scenarios, the risk of potential complications including stent fractures is thought to be higher, though there is no data to determine the prognosis or to outline the outcomes of any management option. We present a case of complete stent fracture 1 year after LIMA percutaneous coronary intervention due to LIMA and subclavian artery dissection highlighting the circumstantial evidence in the literature that guided our management decisions.

Retrograde approach via left internal mammary artery using a 5 Fr guiding catheter

A 64-year-old female, who had undergone CABG previously, was admitted to our hospital because of non-ST elevation myocardial infarction with acute heart failure. The SVG-RCA was judged the culprit vessel because of the angiographical thrombus. However, primary percutaneous coronary intervention (PCI) in the SVG-RCA had a high risk of distal embolism and might have had caused critical slow flow. Primary PCI to the native right coronary artery (RCA) with retrograde approach using the septal channel from left anterior descending artery bypassed by LIMA was successfully performed. A 5 Fr JR-4.0 guiding catheter was deeply engaged to the mid part of LIMA following the microcatheter, and the wire finally reached the distal part of RCA.

Internal mammary artery graft dissection: a case-based retrospective study and brief review

The left internal mammary artery is the preferred graft for treating left anterior descending coronary artery disease. Dissection is a rare but grave sequela of internal mammary artery graft angiography. The available medical literature is scant, perhaps as a result of under-reporting. We report a case in which dissection of the internal mammary artery graft occurred during diagnostic angiography, and we discuss its management. In addition, we review the available literature and provide a retrospective analysis of the data from our own catheterization laboratory. In our single-center analysis of 542 cases of selective internal mammary artery graft angiography, we found only the single case of internal mammary artery graft dissection (0.2%) that we report here. Our review of the literature revealed 7 reported cases of internal mammary artery graft dissection, 3 of which were iatrogenic. There were no identifiable risk factors for such dissection. After treatment with angioplasty and stenting, all patients had good outcomes during follow-up.

Acute occlusion of the left internal mammary artery graft in the late postoperative period

The left internal mammary artery (LIMA) graft used in coronary artery bypass grafting (CABG) reliably revascularizes the left anterior descending artery (LAD) and has excellent long-term patency. Here, we report a rare case of ST-elevation myocardial infarction caused by acute occlusion of the LIMA in the late postoperative period. A 62-year-old man who underwent CABG for a myocardial infarction 15 years previously was transferred to our hospital for the recurrence of acute anterior myocardial infarction. Emergent cardiac catheterization revealed complete occlusion from the mid-portion of the LIMA to the LAD. We successfully treated this patient with primary stent implantation to the culprit LIMA lesion using intravascular ultrasound guidance. <Learning Objective: The left internal mammary artery (LIMA) is commonly used as the conduit to bypass the left anterior descending artery (LAD) and has shown excellent long-term patency. However, we have experienced a rare case with acute myocardial infarction due to acute occlusion of LIMA in late postoperative period. We should carefully monitor, considering that the LIMA could possibly undergo arteriosclerotic changes.>.

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.

Mobile stenosis in a left internal mammary artery graft: a case report

The authors report a case of percutaneous transluminal angioplasty (PTA) with coronary stent for stenosis in a left internal mammary artery (IMA) graft, which led to newly developed stenosis at both sides of the stent in the IMA graft. The intravascular ultrasound (IVUS) revealed that the stenotic lesion consisted of intramural hematoma, which had shifted owing to the stent deployment. They suggest that the cause of stenotic lesions in IMA grafts at the early postoperative period is luminal compression by intramural hematoma, which can be visualized by use of IVUS. The strategy of PTA for IMA grafts performed at the early postoperative period should include consideration for hematoma shift.

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.

Results of angioplasty (with or without stent) at the site of a narrowed coronary anastomosis of the left internal mammary artery graft or via the internal mammary artery

During the past 6 years, 50 patients underwent percutaneous transluminal coronary angioplasty (PTCA) of a narrowed coronary anastomosis of a left internal mammary artery (LIMA) graft or PTCA of a left anterior descending coronary artery stenosis via LIMA grafts at the investigators' institution. The success rate was high at 88%. Thirty-four of the 44 successfully treated patients (77%) underwent repeat angiography, which showed restenosis in 14 patients (41%). In cases of stent implantation at the coronary LIMA graft anastomosis angioplasty site, the restenosis rate was 80%, but it was only 14% in cases of pure balloon dilation (p = 0.001). Therefore, in cases of coronary LIMA graft anastomosis, stent implantation should be avoided, because it implicates an excessively high restenosis rate.

Clinical outcomes following stent implantation in internal mammary artery grafts

We evaluated our experience with percutaneous coronary intervention (PCI) of internal mammary artery (IMA) grafts. From the institution's database we identified 288 patients with 311 IMA lesions. Of these, 82 (26.4%) had stents placed during PCI. Angiographic success was 92%. Mortality at 1 month was 1.7%, myocardial infarction (MI) 15.7%, and target lesion revascularization (TLR) 0.4%. Cumulative 1-year event rates were mortality 6.4%, MI 20.4%, and TLR 8.0%. TLR rates were significantly higher in the stented lesions than lesions treated with angioplasty alone (19.2% vs. 4.9%; P = 0.004). The higher TLR rate in stented lesions was most apparent at the anastomotic site (25.0% vs. 4.2%; P = 0.006). Percutaneous revascularization of IMA grafts can be performed safely with high procedural success and excellent short- and long-term results. Stenting, particularly at the anastomotic site, was associated with significantly greater rates of TLR than angioplasty alone.

The VB-1 catheter: an improved catheter for difficult-to-engage internal mammary artery grafts

As patients with prior coronary artery bypass grafting age, internal mammary artery grafts are more frequently encountered in the cardiac catheterization laboratory. Angiography and interventions involving these grafts are often difficult, particularly in patients with tortuous subclavian anatomy and/or proximal internal mammary artery origins. We describe a new catheter shape, the Cordis Behar Internal Mammary, VB-1, which allows selective intubations of both right and left internal mammary arteries that are not possible with conventional catheters.

Percutaneous interventions in radial artery grafts: clinical and angiographic outcomes

In the modern era, radial artery graft is being used with increasing frequency to replace saphenous vein as a conduit for coronary artery bypass surgery. Several reports have shown encouraging early results of radial grafts compared to saphenous grafts. Despite these advantages, radial artery graft failure requiring revascularization does occur. We report on the clinical, angiographic, and technical characteristics and the follow-up results of 22 patients who underwent percutaneous intervention of radial grafts.

Use of a pigtail catheter to engage a difficult internal mammary artery

Increasing use of bilateral internal mammary arteries for coronary surgery will increase the number of interventions in these grafts. Such interventions may be technically challenging because of often tortuous and angulated vessels. We describe a technique to intubate an acutely angulated right internal mammary artery that was inaccessible with conventional catheters.

An unusual case of left internal mammary artery ostial disease: clarifying role of intravascular ultrasound

Stenosis at the origin of the left internal mammary artery graft is rare. We present a case with a suspected stenosis involving the origin of the left internal mammary artery that conventional angiography failed to demonstrate convincingly. Intravascular ultrasound illustrated a severe stenosis and the patient underwent successful stenting of the left internal mammary artery origin. The intravascular ultrasound finding of a dissection flap, just distal to the left internal mammary artery origin, suggests that local trauma to the vessel from prior catheterization procedures may have been responsible for the progressive narrowing at the left internal mammary artery ostium.

Comparison of event and procedure rates following percutaneous transluminal coronary angioplasty in patients with and without previous coronary artery bypass graft surgery [the ROSETTA (Routine versus Selective Exercise Treadmill Testing after Angioplasty) Registry]

To compare 6-month post-percutaneous transluminal coronary angioplasty (PTCA) outcomes and cardiac procedure use among patients with and without prior coronary artery bypass graft (CABG) surgery, we examined 791 patients who were enrolled in the Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) Registry. The ROSETTA Registry is a prospective, multicenter registry that examines the use of functional testing after successful PTCA. Most patients were men (76%, mean age 61 +/- 11 years) who underwent single-vessel PTCA (85%) with stent implantation (58%). Baseline and procedural characteristics differed between patients with a prior CABG (n = 131) and patients with no prior CABG (n = 660), including Canadian Cardiovascular Society angina class III to IV (60% vs 49%, respectively, p = 0.03) and stenosis involving the proximal left anterior descending coronary artery (10% vs 22%, p = 0.004). Event rates among patients with prior CABG were higher than among patients with no prior CABG, including unstable angina (19% vs 11%, p = 0.02), myocardial infarction (2% vs 1%, p = 0.2), death (4% vs 2%, p = 0.08), and composite clinical events (22% vs 12%, p = 0.003). Furthermore, patients with prior CABG had higher rates of follow-up cardiac procedures, including angiography (24% vs 14%, p = 0.008) and PTCA (13% vs 7%, p = 0.04), but not repeat CABG (2% vs 3%, p = 0.8). A multivariate analysis that included baseline clinical and procedural characteristics demonstrated that prior CABG was a significant independent predictor of clinical events and cardiac procedure use (odds ratio 2.3, 95% confidence interval 1.5 to 3.5, p = 0.0001). Within the prior CABG group, patients with a PTCA of a bypass graft had a higher composite clinical event rate than patients with a PTCA of a native vessel (32% vs 17%, p = 0.05). In contrast, patients with a PTCA of a native vessel had event rates similar to those of patients with no prior CABG (17% vs 12%, p = 0.2). Thus, post-CABG patients have an increased risk of developing a cardiac event or needing a follow-up cardiac procedure during the 6 months after PTCA.

Brachytherapy for in-stent restenosis through the internal mammary artery

We report five cases treated with brachytherapy through the internal mammary artery (IMA) for in-stent restenosis at the distal anastomosis (n = 3) and in the left anterior descending coronary artery beyond the distal anastomosis (n = 2). After angioplasty, catheter-based gamma radiation was performed. There was no delivery failure of the radiation system. All cases had angiographic success and no procedural or in-hospital complications.