Aberrant right coronary artery occlusion during the percutaneous pulmonary trunk stenting in a patient with tetralogy of Fallot.

Aberrant coronary arteries are frequently observed in patients presenting with Fallot's tetralogy (TOF). Before the complete surgical repair of the TOF, the percutaneously performed pulmonary trunk (PT) angioplasty is often performed in order to temporarily increase the pulmonary circulation, thus increasing the pulmonary vessel size, finally improving surgical outcome. This case reports a 12-year-old boy with a TOF insufficiently improved by surgical correction, in whom a PT angioplasty with stent implantation was complicated by an extrinsic compression of an aberrant right coronary artery (RCA) causing a myocardial ischemia with severe hypotension. The RCA, originating from the left anterior descending coronary artery, passed through the aortic root and the PT and was thus compressed by the PT-stent. Finally the RCA was successfully treated with standard coronary balloon angioplasty and stenting, improving myocardial perfusion and the hemodynamics of the patient, who finally died several days thereafter due to septic shock and massive pulmonary embolism.

Coronary myocardial bridge: an innocent bystander?

Myocardial bridge (MB) or tunneled coronary artery is an inborn abnormality, which implicates a systolic vessel compression with a persistent mid-late diastolic diameter reduction. Myocardial bridges are often observed during coronary angiography with an incidence of 0.5%-5.5%. The most involved coronary artery is the left anterior descending artery followed by the diagonal branches, the right coronary artery, and the left circumflex. The overall long-term prognosis is generally benign. However, several risk or precipitating factors (e.g., high heart rate, left ventricular hypertrophy, decreased peripheral vascular resistance) may trigger symptoms (most frequently angina). Herein, we describe two cases of symptomatic myocardial bridge, where medical treatment (i.e., inotropic negative drug) and coronary stenting were successfully utilized to treat this pathology. We also focus on the clinical presentation, and the diagnostic and therapeutic modalities to correctly manage this frequently observed congenital coronary abnormality, underlining the fact that in cases of typical angina symptoms without any significant coronary artery disease, MB should be considered as a possible differential diagnosis.

Differentiated analysis of an everolimus-eluting stent and a paclitaxel-eluting stent among higher risk subgroups for restenosis: results from the SPIRIT II trial.

AIMS: Restenosis is higher among certain subpopulations when subjected to percutaneous coronary interventions even when using drug-eluting stents. The randomised SPIRIT II trial demonstrated the superiority of the XIENCE V Everolimus Eluting Coronary Stent System over the TAXUS Paclitaxel-Eluting Stent System in terms of in-stent late loss at six months among 300 patients treated for de novo native coronary artery lesions. METHODS AND RESULTS: In this post-hoc analysis of SPIRIT II we focused on six-month angiographic outcomes of diabetic patients (n=69), left anterior descending arteries (n=149), long lesions >20 mm (n=43), small vessels <3.0 mm (n=209) and type B2 and C lesions (n=233). In-stent late loss was consistently less among all subgroups when treated by everolimus-eluting stents compared to paclitaxel-eluting stents: diabetics 0.15+/-0.26 mm versus 0.39+/-0.34 mm, p=0.006; LAD 0.12+/-0.23 mm versus 0.44+/-0.37 mm, p<0.001; long lesions 0.13+/-0.26 mm versus 0.43+/-0.46 mm, p=0.070; small vessels 0.17+/-0.28 mm versus 0.37+/-0.39 mm, p<0.001; B2/C lesions 0.12+/-0.31 mm versus 0.36+/-0.36 mm, p<0.001. CONCLUSION: The everolimus-eluting stent remained superior in terms of in-stent late loss in a variety of higher risk populations for restenosis compared to the paclitaxel-eluting stent. These analyses were consistent with the in-stent late loss results of the overall SPIRIT II trial population.

Feasibility of the PCI through 6F diagnostic catheters.

BACKGROUND: The choice of guiding catheter for optimal back-up support is critical in order to achieve a successful PCI. Diagnostic 6 French (F) catheters have an internal lumen diameter as large as 5F guiding catheters. The aim of this study was to demonstrate for the first time the feasibility of performing PCI with Cordis 6F diagnostic catheters in selected coronary lesions. METHODS: 32 coronary stents were implanted using 6F diagnostic catheters in 27 eligible patients at the Montreal Heart Institute. The inclusion criteria were TIMI angiographic score < B2 in native coronary arteries or in coronary artery bypass grafts. Bifurcations and left main disease were not included. RESULTS: Eighty-five percent of the patients underwent PCI for acute coronary syndromes (ACS). PCI was performed in 5 lesions (19%) of the left coronary circulation; in 21 lesions (78%) of the right coronary artery and in one lesion (4%) of the 1st obtuse marginal branch of the circumflex artery, through a left mammary artery bypass. Only stents suitable for 5F guiding catheters were used. The largest stent was 4.0 mm in diameter and 32 mm in length. Direct stenting was performed in 75% of patients. The angiographic success for PCI of target lesions was 100%, without clinical or angiographic complications. CONCLUSIONS: In selected cases, diagnostic 6F catheters can be used for PCI with 5F compatible balloons and stents. PCI via a diagnostic catheter may provide even better back-up support and allows for significant resources and time savings, especially in patients with ACS.

Interatrial septum rupture during balloon measurement of a patent foramen ovale in a young patient presenting cryptogenic stroke.

We report the case of a 36-year-old woman admitted for cryptogenic stroke, in whom the Patent Foramen Ovale (PFO) diameter measurement, with a purpose built sizing balloon, performed before the closure procedure, was complicated with the rupture of the inter-atrial septum generating an Atrial Septal Defect (ASD) with a significant left-to-right shunt. This kind of complication may not be easy to handle, changing the initial procedural strategy from PFO to ASD closure technique requiring specific material and operator's technical skill.

Feasibility and safety of intra-coronary Beta irradiation with 144Ce/Pr for prevention of restenosis after percutaneous transluminal coronary angioplasty of in-stent restenotic lesions.

BACKGROUND: Endovascular brachytherapy is a proven and efficacious treatment of coronary in-stent restenosis with established long-term benefit. Owing to its complexity and logistic inconveniences, brachytherapy did not find wide acceptance, especially in the current drug-eluting stents era. We conducted a single center, non-randomized pilot trial with 144Ce/Pr, utilizing a new high-energy Beta emitting source, for prevention of restenosis after percutaneous treatment of in-stent restenotic lesions. METHODS AND RESULTS: Thirty consecutive patients presenting in-stent restenosis were enrolled in the study. After conventional balloon angioplasty, 144Ce/Pr was applied to the dilated coronary segment at a dose of 21Gy. Technical feasibility, safety and efficacy of 144Ce/Pr at 9 months clinical and angiographic follow-up were tested. Thirty-seven arterial segments were irradiated with 100% technical success and no in-hospital major adverse cardiac events (MACE). Five MACE were observed (13.5% of the treated segments) during 9 months follow-up, including four target lesion revascularizations and one episode of acute coronary syndrome secondary to sudden late thrombotic occlusion of the irradiated segment. CONCLUSIONS: The study confirmed the safety and the feasibility of the intra-coronary Beta irradiation utilizing the 144Ce/Pr source. It also shows some practical advantages compared to traditional Gamma or other Beta sources. Considering the high-risk restenosis profile of the selected patients (i.e. diffuse in-stent restenosis, bifurcation lesions, small vessels) these results are encouraging in terms of restenosis prevention. Late acute thrombosis remains a problem requiring further improvement.

Late cardiac tamponade after percutaneous closure of a patent foramen ovale.

We report the case of a 35-year-old man who had a transient ischemic cerebral attack and then underwent a percutaneous closure of the patent foramen ovale (PFO) with a Cardiastar device. One year later, the patient developed a cardiac tamponade due to an important hemorrhagic pericardial effusion. Transoesophageal echocardiography showed that one of the struts had impinged on the aortic root in the region adjacent to the transverse pericardial sinus. Therefore, we speculated that the strut had passed through the aortic wall by slow erosion, leading to the pericardial effusion. Cardiac CT and subsequent surgery confirmed the perforation of the left atrial roof and the aortic root by two struts of the device. This is the first reported case of late cardiac tamponade and underscores the importance of long-term follow-up after PFO closure device implantation.

High-risk left main coronary stenting supported by percutaneous left ventricular assist device.

Percutaneous left ventricular assist devices could nowadays offer a valid support to percutaneous coronary interventions even in very high risk patients. This case illustrates a successful distal left main coronary artery V-stenting supported by the Tandem Heart in a patient with severe left ventricular dysfunction, severe aortic stenosis, and refractory myocardial ischemia.

Biological aspects of radiation and drug-eluting stents for the prevention of restenosis.

Based on recent advances, this article aims to review the biological basis for the use of either radiation or drug-eluting stents for the prevention of restenosis, and to elucidate the complementary role that they may play in the future. Vascular restenosis is a multifactorial process primarily driven by the remodeling of the arterial wall, as well as by the hyperproliferation of smooth muscle cells (SMC). These pathophysiological features are the target of therapeutic strategies aimed at inhibiting constrictive remodeling as well as inhibiting SMC proliferation. The success of radiation as well as anti-proliferative drugs such as paclitaxel and sirolimus lies in the primary and/or multifactorial inhibition of cell proliferation. Radiation has the additional feature of preventing constrictive remodeling while sirolimus has the potential property of being anti-inflammatory, which may be a desirable feature. The effects of radiation are not reliant on any uptake and "metabolism" by the target cells, as in the case with drugs, and thus radiation potentially may be more effective as a result of its more-direct action. However, radiation does have some significant drawbacks compared to drug-eluting stents, including a much delayed re-endothelialization resulting in the need for prolonged anti-platelet therapy. Based on recent clinical data, drug-eluting stents have been shown to markedly reduce the likelihood of restenosis, which actually favors this approach for the prevention of restenosis. From a biological perspective, drug-eluting stents and radiation have certain differences, which are reviewed in this article.

A case of renal artery brachytherapy for in-stent restenosis: four-year follow-up.

Renal artery stent implantation is associated with high rates of restenosis, particularly in vessels less than 4.5 mm in diameter. We describe 4-year follow-up results in the first patient to receive renal artery brachytherapy for this indication. A 68-year-old man who presented with flash pulmonary edema, hypertension and renal impairment was found to have severe bilateral renal artery stenosis and was treated with bilateral stent implantation. Following clinical deterioration due to severe in-stent restenosis, he underwent repeat angioplasty followed by intra-stent brachytherapy. To our knowledge, this is the first use of such therapy and hence the 4-year follow-up demonstrating excellent bilateral patency is the longest to date.

In-hospital complications of percutaneous intraaortic balloon counterpulsation.

Complications related to intraaortic balloon counterpulsation pumping (IABP) remain a problem despite the development of small caliber balloon catheter shafts and introducer sheaths. The authors report their experience in counterpulsation-related complications of 201 consecutive patients who underwent 212 percutaneous counterpulsation balloon insertions from June 1989 to June 1996 by use of balloons with 8-9.5 French shafts. Of these, 82% were men and 36 (18%) were women, with a mean age of 61 +/-12 years. Indications for counterpulsation were acute myocardial infarction (AMI) (67%), severe left ventricular failure without AMI (20%), dilated cardiomyopathy (4%), unstable angina (3%), high-risk supported percutaneous coronary angioplasty (2%), and others (4%). IABP was instituted at the bedside in the intensive care unit in 82 patients (39%) and in the catheterization laboratory in 130 (61%). Median duration of counterpulsation was 48 hours (range 30 minutes to 25 days) with successful weaning from counterpulsation in 70% (148 of 212) of procedures. Overall in-hospital mortality rate was 45% (90 of 201). The overall complication rate was 22/212 (10.4%). Major complications were present in 10/212 procedures (4.7%): 6 patients with limb ischemia (1 death directly attributed to this complication, 1 with associated septicemia and limb amputation, 3 requiring surgical thromboembolectomy, and 1 with persistent limb ischemia treated medically until his death caused by intractable left ventricular failure), 2 with important bleeding (1 fatal despite vascular surgical repair and 1 requiring blood transfusion) and 2 with balloon rupture requiring vascular surgery. Minor complications were present in 12 procedures (5.7%), 6 with limb ischemia, 3 with local bleeding, and 3 with catheter dysfunction. All of these resolved after balloon removal and required no further intervention. When limb ischemia did develop it occurred after a median delay of 24 hours following balloon insertion (range 2 to 98 hours). The only predictor of limb ischemia among baseline clinical and procedure-related variables was an age greater than 60 years. Compared with previous recent studies, the rate of complications observed in this study performed with small balloon catheters was acceptably low. Limb ischemia was the most frequent complication, often occurred early, and required further intervention in half the cases.

Time savings with prehospital thrombolysis in an urban area.

The aim of this study was to evaluate the time saved by prehospital thrombolysis compared with the usual inhospital reperfusion strategies in Geneva, Switzerland, a moderate-sized urban area with short transportation times (median time 4 min). Patients with acute myocardial infarction, diagnosed clinically and by means of a 12-lead electrocardiogram in a mobile intensive care unit, without contraindications to thrombolysis, were randomly assigned either to 'prehospital thrombolysis' or to 'usual hospital care', i.e. inhospital reperfusion strategies (thrombolysis or primary angioplasty). Sixteen patients with similar clinical characteristics were randomly selected. The mean time between the arrival of the physician by the patient and the initiation of therapy was shorter for 'prehospital thrombolysis' (26.0+/-10.3 min) than for 'usual hospital care' (94.93+/-6.3 min, P=0.0004). Time savings were even greater when time between the beginning of symptoms and the initiation of therapy was analysed (152.6+/-76.6 versus 251.2+/-86.3 min, P=0.0004). We concluded that, even in an urban area with a readily available catheterization laboratory, prehospital thrombolysis can be initiated safely immediately after the diagnosis of acute myocardial infarction, and is time saving.

Heterogeneity of smooth muscle cell populations cultured from pig coronary artery.

OBJECTIVE: Heterogeneous smooth muscle cell (SMC) populations have been described in the arteries of several species. We have investigated whether SMC heterogeneity is present in the porcine coronary artery, which is widely used as a model of restenosis. METHODS AND RESULTS: By using 2 isolation methods, distinct medial populations were identified: spindle-shaped SMCs (S-SMCs) after enzymatic digestion, with a "hill-and-valley" growth pattern, and rhomboid SMCs (R-SMCs) after explantation, which grow as a monolayer. Moreover, the intimal thickening that was induced after stent implantation yielded a large proportion of R-SMCs. R-SMCs exhibited high proliferative and migratory activities and high urokinase activity and were poorly differentiated compared with S-SMCs. Heparin and transforming growth factor-beta2 inhibited proliferation and increased differentiation in both populations, whereas fibroblast growth factor-2 and platelet-derived growth factor-BB had the opposite effect. In addition, S-SMCs treated with fibroblast growth factor-2 or platelet-derived growth factor-BB or placed in coculture with coronary artery endothelial cells acquired a rhomboid phenotype. This change was reversible and was also observed with S-SMC clones, suggesting that it depends on phenotypic modulation rather than on selection. CONCLUSIONS: Our results show that 2 distinct SMC subpopulations can be recovered from the pig coronary artery media. The study of these subpopulations will be useful for understanding the mechanisms of restenosis.