Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT.

Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (ΔP) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation ΔP. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of ΔP across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed ΔP was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coefficient (PLc), time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI), were also quantified. CFD-estimated ΔP values were comparable to the invasive ones. Moreover, the aorta proximal to CoA was exposed to altered TAWSS and OSI suggesting hypertension. PLc was found as a further geometric marker of CoA severity. Finally, CFD-estimated ΔP confirmed a significant reduction after percutaneous balloon dilatation and stenting of the CoA in one patient (e.g. from ΔP∼52 mmHg to ΔP∼3 mmHg). The validation of the ΔP computations with catheterisation measurements suggests that CFD simulation, based on CT-derived anatomical data, is a useful tool to readily quantify CoA severity.

Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis.

We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in the region of the PAU. After endovascular treatment, these haemodynamic parameters were distributed uniformly on the luminal surface of the stent graft. These findings suggest that wall shear stress could be considered one of the major haemodynamic factors indicating the structural fragility of the PAU wall, which ultimately lead to PAU growth and rupture.

Atrial septostomy in patients with end-stage pulmonary hypertension. No more needles but wires, energy and close anatomical definition.

OBJECTIVES: To assess the usefulness of a new approach to atrial septal puncture and septostomy in patients with end-stage pulmonary hypertension. BACKGROUND: Atrial septostomy in end-stage pulmonary hypertension has high mortality and morbidity rates mainly due to trans-septal catheterization. New approaches to safety during this technical step are expected. METHODS: Twelve patients with end-stage pulmonary arterial hypertension (5 males, 7 females, mean age 41, 9 ± 12, 0 years) underwent to balloon atrial septostomy. Intracardiac echography (ICE) was used to localize fossa ovalis while a radiofrequency wire was used to perforate the atrial septum. Then a septostomy was performed by progressive balloon dilatation of atrial septum. Septal perforation was successful at the first attempt in 4 patients and after 5 attempts in a single case, while Bas was successful in all. RESULTS: Pericardial effusion did not develop in any patient. Complications consisted in transient supraventricular tachyarrhythmia, transient cerebral ischemia and severe hypoxemia with ventricular tachycardia in 3 single patients. In-procedure death rate was 0%. Systemic cardiac output increased immediately, while systemic O2 saturation decreased significantly in all. Mean follow-up was 8, 2 ± 3, 8 months. Mortality was 16.6% (2 patients). NYHA class improved in the rest of patients. Four patients (33.2%) underwent to pulmonary transplant successfully. CONCLUSIONS: This novel approach for trans-septal catheterization has shown very low rate of major complication during atrial septostomy in patients with end-stage pulmonary arterial hypertension.

The new patent foramen ovale occluder FIGULLA in complex septal anatomy: a case series.

BACKGROUND: The appropriate treatment strategy for secondary stroke prevention in patients with cryptogenic stroke and patent foramen ovale (PFO) remains challenging. The aim of this study was to describe a case series of patients with PFO and complex septal anatomy who underwent percutaneous correction using a FIGULLA (Occlutech) septal occluder (FSO). PATIENTS: Ten consecutive patients (6 females, 4 males, mean age 41.6 ± 16.0 years, range 17-52 years; group 1) with cryptogenetic stroke and/or transient cerebral ischemia and complex septal anatomy, as defined by intraprocedural transesophageal echocardiogram (TEE) were compared with a group of 25 patients (10 females, 15 males, mean age 43.7 ± 12.3 years; group 2) with usual tunnel-like PFO anatomy in whom PFO was closed by an Amplatzer septal occluder (ASO; AGA). RESULTS: No significant differences were noted between group 1 and group 2 for immediate success rate, residual intraprosthetic shunt at the end of the procedure, discharge, 1, 6 and 12 months follow up, number of attempts, procedure time, fluoroscopy time, or cardiac complication (atrial arrhythmias, device embolism). The only significant difference was shown for delivery sheath size (11 ± 2 versus 9 ± 1 F) and incidence of local hematoma (30% versus 12%) between group 1 and group 2, without any clinical consequence (need of transfusion) or increase in length of stay. CONCLUSION: FSO shows high performance in patients with PFO and complex septal anatomy when compared with patients with PFO and uncomplicated atrial anatomy treated by ASO. Its favorable behavior is probably related to fabric features such as the total amount of metal and the presence of titanium.

Left main coronary in-stent intimal hyperplasia and hemodynamics as detected by contrast-enhanced transesophageal echocardiography.

PATIENTS AND METHODS: In-stent hemodynamics were studied by transesophageal echocardiography (TEE) in a group of 54 patients after left main coronary artery stenting, during a 6-month follow-up. TEE was performed within 24 hours after stenting and at 1- and 3-month follow-up. Pulsed wave and color Doppler signals were enhanced by IV administration of Levovist. RESULTS: Angiographic immediate success was obtained in all patients. No in-hospital death occurred. Ten patients (18.4%) complained of recurrent angina at the follow-up of 4.8 ± 1.2 months. Both TEE and coronary angiography confirmed in-stent restenosis in all. Thirty-nine patients (68.5%) remained symptoms free. Mean late loss in these patients was 0.69 ± 0.20 mm. A linear significant positive relation between mean late loss values and diastolic coronary velocity (r: 0.89, P < 0.001) was found. After 3- and 6-month follow-up, PDV showed a significant increase in comparison with basal values (0.7 ± 0.3 and 0.6 ± 0.26 vs. 0.32 ± 0.2 cm/sec, P < 0.01). All patients with restenosis showed a significant increase of diastolic coronary velocity in comparison with basal values (2.89 ± 0.25 cm/sec, P < 0.001). CONCLUSION: TEE can predict the development of in-stent intimal hyperplasia in patients with unprotected left main coronary artery stenting.

Can learning to interpret pump messages help lead to an early diagnosis of HeartWare ventricular assist device thrombosis?

Left ventricular assist device thrombosis is a detrimental complication that, if not properly diagnosed and treated, can lead to low output syndrome and death. When ongoing thrombus formation is caused by inappropriate anticoagulation, timely identification is possible, and could perhaps be the key to successful treatment.

Six-month echocardiographic study in patients with submassive pulmonary embolism and right ventricle dysfunction: comparison of thrombolysis with heparin.

INTRODUCTION: The aim of this study was to assess the effect of thrombolysis versus heparin treatment on echocardiographic parameters and clinical outcome, during hospitalization and within the first 180 days after admission, in patients with first episode of submassive pulmonary embolism (SPE) and right ventricle dysfunction (RVD). METHODS: Consecutive patients (age, 18-75 years) with a first episode of SPE, symptoms onset since no more than 6 hours, normal blood pressure (>100 mm Hg), echocardiographic evidence of RVD and positive lung spiral computed tomography were double-blind randomized: 1 group received 100 mg of alteplase (10-mg bolus, followed by a 90-mg intravenous infusion over a period of 2 hours), while the other group received matching placebo. In addition to alteplase or placebo, both groups received an unfractionated heparin treatment. Echocardiogram was performed at admission, at 24, 48 and 72 hours, at discharge and at 3 and at 6 months after randomization. RESULTS: Seventy-two patients were included into the study; 37 were assigned to thrombolysis and 35 to placebo. Both groups were well matched with regard to features and clinical presentation. Thrombolysis group showed a significant early improvement of RV function compared with heparin group, and this improvement was observed also during the follow-up (180 days). The same group also showed significant reduction in clinical events during the hospitalization and follow-up. CONCLUSIONS: Our data suggest that, in hemodynamically stable patients with SPE, thrombolysis shows an earliest reduction of RVD and a more favorable trend in clinical outcome, so, it could merit consideration in SPE.

Reduction of a previous atrial septostomy in a patient with end-stage pulmonary hypertension by a manually fenestrated device.

A case of profound systemic oxygen desaturation after atrial septostomy in a patient with primitive pulmonary hypertension is reported. A new method to correct such severe complication of atrial septostomy is described, consisting in a graded reduction of the right to left atrial shunt by deployment of a manually perforated atrial septal closure device.

Use of bivalirudin for heparin-induced thrombocytopaenia after thrombolysis in massive pulmonary embolism: a case report.

A 68-year-old man was referred to the emergency department 6 h after onset of sudden acute dyspnoea. Immediate ECG showed sinus tachycardia with the typical S1-Q3-T3 pattern and incomplete right bundle branch block. The echocardiogram showed the presence of mobile thrombus in the right atrium, a distended right ventricle with free wall hypokinesia and displacement of the interventricular septum towards the left ventricle. Lung spiral computed tomography (CT) showed bilateral pulmonary involvement and confirmed the picture of a thrombotic system in the right atrium and caval vein. Thrombolytic treatment with recombinant tissue plasminogen activator (rt-PA) and heparin (alteplase 10 mg bolus, then 90 mg over 2 h) was administered. Six hours after thrombolysis bleeding gums and significant reduction in platelet count (around 50,000) were observed. Heparin was discontinued and bivalirudin (0.1 mg/kg bolus and 1.75 mg/kg per h infusion) plus warfarin was initiated and continued for 5 days until the international normalised ratio (INR) was within the therapeutic range (2.0-3.0) for 2 consecutive days, with concomitant platelet count normalisation. Lung spiral and lower abdominal CT before discharge did not show the presence of clots in the pulmonary arteries of the right and left lung. This case suggests that bivalirudin could offer promise for use in patients with heparin-induced thrombocytopaenia (HIT) after thrombolysis for massive pulmonary embolism.

Hybrid treatment of inferior vena cava obstruction after orthotopic heart transplantation.

Caval stenosis with subsequent thrombosis may occur after orthotopic heart transplantation (HT). Management of this complication may include a percutaneous approach or an open surgical one. Here, we report the case of an obstruction and severe thrombosis of the inferior vena cava, following orthotopic HT, that was managed in a hybrid fashion with surgical venous thrombectomy, inferior vena cava stenting, and atrio-caval patch-plasty.

In-stent thrombosis after 68 months of implantation inspite of continuous dual antiplatelet therapy: a case report.

Lately, there has been an increased incidence of late stent thrombosis; especially following Drug eluting stent (DES) implantation. Several factors are associated with an increased risk of stent thrombosis, including the procedure itself, patient and lesion characteristics, stent design, and premature cessation of anti-platelet drugs. We present a case of late stent thrombosis (LST) following DES implantation after a period of 68 months, making it the longest reported case of LST reported in the literature, despite the use of dual anti-platelet therapy.

Tamponade following breast augmentation.

Breast augmentation is one of most commonly performed cosmetic surgical procedures. Pneumothorax has been reported as a rare complication of breast augmentation but the incidence is not known. Our patient presented with dyspnea on exertion about 6 days following breast augmentation. She was found to have cardiac tamponade and pneumothorax. We present a case of cardiac tamponade following breast augmentation, a previously unreported complication.

A planned hybrid culotte stenting procedure in the setting of an acute STEMI.

INTRODUCTION: Bifurcation lesions have traditionally presented a unique problem for interventional cardiologists because of their inherent anatomy and risk of closure of the side branch, after a percutaneous intervention for the primary lesion of the main branch. CASE PRESENTATION: We report the case of a 57-year-old man who presented with acute ST-segment elevation myocardial infarction secondary to a 100% occlusion at the ostium of first diagonal (D1) branch. Patient also had a 70% stenosis of the mid-segment of the left anterior descending (LAD) coronary artery at the D1 branching point (1,1,1 Medina classification). A bare metal stent (BMS) was deployed at the site of the culprit lesion in the D1, while a drug eluting stent (DES) was placed in the LAD. We believe that the BMS at the culprit thrombotic, inflamed site in D1 is more likely to re endothelialize than a DES and the DES in the LAD, is less likely to re-stenose than a BMS. CONCLUSION: This is the only reported case, where in the setting of an acute ST elevation myocardial infarction, a hybrid Culotte technique was successfully performed with excellent long-term results, thus achieving an acceptable balance of risks between restenosis (in the case of a BMS) and stent thrombosis (in the case of a DES).

Endovascular treatment of a symptomatic carotid artery aneurysm with a stent graft.

Endovascular methods have become more widespread and offer an alternative to surgery, which is often difficult in case of a hostile neck resulting from radiotherapy. Carotid pseudoaneurysm after laryngectomy is a very uncommon complication. We report a case of symptomatic carotid artery pseudoaneurysm treated using a stent graft.

Left anterior descending coronary artery bridge: contraindication to cardiac transplantation?

We report two cases of cardiac transplantation of donor hearts with left anterior descending (LAD) myocardial bridging (MB). In the first case, the diagnosis was done only days after transplant. In the second case, a pre-operative angiography showed evidence of LAD myocardial bridging and the organ was used for a marginal recipient. Both patients tolerated the procedure very well and did not have peri-operative cardiac complications. In this study, MB is discussed and its relationship to rejection of donor hearts is evaluated. In light of the growing demand for donated hearts, and in consideration of the relatively high and often undiagnosed occurrence of MB, a liberalized approach to acceptance of this anatomic variant could be adopted in the selection of donor hearts. Identification of MB in the prospective donor heart should not be an absolute contraindication for transplantation.

Culotte bifurcation stenting with paclitaxel drug-eluting stent.

The results of using the culotte bifurcation technique have not been promising with regard to bare metal stents; however, some possible advantages with regard to drug-eluting stents (DES) must be taken into account, such as the possibility to stent provisionally, to use lower French sizes, and to completely cover the coronary wall and the new carina with a single or double stent layer. The crush technique, which aims to reach a complete coverage of the coronary wall to allow antiproliferative drugs to homogeneously distribute into the coronary walls, has been introduced. The culotte technique seems to act more physiologically, allowing the creation of a new, homogeneously covered carina, without any crushed metal inside the coronary wall. We present the case of a coronary bifurcation treated with the use of the culotte technique and paclitaxel-eluting stent deployment, with good angiographic results after 10 months of follow-up. Further data are needed to evaluate the potential utility of the culotte technique in treating bifurcation coronary lesions in the area of DES.

Intracardiac echocardiography in monitoring atrial septal defect percutaneous closure: initial experience in an adult laboratory.

Two cases of percutaneous closure of atrial septal defect and patent foramen ovale with intracardiac echo monitoring are described. Intracardiac echocardiography was compared to contemporary TOE with full data concordance. The inherent implications and limitations of this new method are discussed.

Simultaneous double-culprit in-stent thrombosis. Who is the guilty prisoner behind bars: drug-eluting stent, bare-metal stent, or indication for treatment?

BACKGROUND: The intrinsic thrombogeneity of stents was the historic limitation to their usage during the early phases of stenting. The risk of stent thrombosis has been minimized by the widespread use of platelet antiaggregation. Nowadays, the risk of subacute stent thrombosis is around 1%. Thrombotic risk depends on several factors, such as type of stent, complexity of lesion, and clinical picture. CASE REPORT: We present a case of recurrent acute in-stent thrombosis in a patient with mild antithrombin III (AT) deficiency despite the combined administration of clopidogrel and aspirin. CONCLUSION: In our patient, several factors, such as diabetes, AT deficiency, and the use of a paclitaxel-eluting stent, have contributed to the development of recurrent acute stent thrombosis. Although we were not able to identify the culprit factor, we should keep in mind that the deployment of a drug-eluting stent could be unsafe if it is not supported by a clear clinically oriented pathway that considers the overall condition of the patient since, in some cases, neither coronary lesions nor coronary stents are responsible for the negative outcome of patient therapy, which may be caused instead by incomplete or inadequate patient assessment.

Downstream administration of a high-dose tirofiban bolus in high-risk patients with unstable angina undergoing early percutaneous coronary intervention.

BACKGROUND: The best treatment option for high-risk patients with unstable coronary syndrome is an early invasive strategy accompanied by intensive anti-platelet therapy. We tested the effect on clinical outcome of early coronary angioplasty using a high-dose bolus of tirofiban in patients with non-ST segment elevation acute coronary syndrome. METHODS: One hundred and forty consecutive patients with unstable coronary syndrome who underwent an immediate percutaneous coronary intervention with the administration of a high (25 microg/kg) dose bolus of tirofiban followed by an 18-h infusion of 0.15 microg kg(-1) min(-1) were compared with a matched control group of 162 patients treated with abciximab. The primary endpoint of the study was the 30-day incidence of major adverse cardiac events; the secondary endpoints were the incidence of major and minor bleeding. RESULTS: The time from admission to PCI was slightly shorter in the tirofiban group (3.9+/-4.8 vs. 4.5+/-4.4 h; P=0.26). The 30-day rate of major adverse cardiac events was similar in the two groups (6% with tirofiban and 8.6% with abciximab: OR=1.37, 95% CI=0.58-3.29, P=0.52). No major bleeding episodes were observed; the incidence of minor bleeding was 3.6% in the tirofiban group and 2.5% in the abciximab group (OR=0.68, 95% CI=0.18-2.59, P=0.74). CONCLUSIONS: In this preliminary study, the beneficial effect of the administration of a high-dose tirofiban bolus on 30-day clinical outcomes was similar to that of abciximab in high-risk patients with unstable angina undergoing immediate percutaneous coronary intervention. The results of this therapeutic strategy should be tested in a larger randomised study.