Primary percutaneous coronary intervention for unprotected left main disease in patients with acute ST-segment elevation myocardial infarction the AMIS (Acute Myocardial Infarction in Switzerland) plus registry experience.

OBJECTIVES: This study sought to assess outcomes in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI) for unprotected left main (LM) disease. BACKGROUND: Limited data are available on outcomes in patients with ST-segment elevation myocardial infarction undergoing LM PCI. METHODS: Of 9,075 patients with ST-segment elevation myocardial infarction enrolled in the AMIS (Acute Myocardial Infarction in Switzerland) Plus registry between 2005 and June 30, 2010, 6,666 underwent primary PCI. Of them, 348 (5.2%; mean age: 63.5 ± 12.6 years) underwent LM PCI, either isolated (n = 208) or concomitant to PCI for other vessel segments (n = 140). They were compared with 6,318 patients (94.8%; mean age: 61.9 ± 12.5 years) undergoing PCI of non-LM vessel segments only. RESULTS: The LM patients had higher rates of cardiogenic shock (12.2% vs. 3.5%; p < 0.001), cardiac arrest (10.6% vs. 6.3%; p < 0.01), in-hospital mortality (10.9% vs. 3.8%; p < 0.001), and major adverse cardiac and cerebrovascular events (12.4% vs. 5.0%; p < 0.001) than non-LM PCI. Rates of mortality and major adverse cardiac and cerebrovascular events were highest for concurrent LM and non-LM PCI (17.9% and 18.6%, respectively), intermediate for isolated LM PCI (6.3% and 8.3%, respectively), and lowest for non-LM PCI (3.8% and 5.0%, respectively). Rates of mortality and major adverse cardiac and cerebrovascular events for LM PCI were higher than for non-LM multivessel PCI (10.9% vs. 4.9%, p < 0.001, and 12.4% vs. 6.4%, p < 0.001, respectively). LM disease independently predicted in-hospital death (odds ratio: 2.36; 95% confidence interval: 1.34 to 4.17; p = 0.003). CONCLUSIONS: Emergent LM PCI in the context of acute myocardial infarction, even including 12% cardiogenic shock, appears to have a remarkably high (89%) in-hospital survival. Concurrent LM and non-LM PCI has worse outcomes than isolated LM PCI.

Free-breathing 3 T magnetic resonance t(2)-mapping of the heart.

OBJECTIVES: This study sought to establish an accurate and reproducible T(2)-mapping cardiac magnetic resonance (CMR) methodology at 3 T and to evaluate it in healthy volunteers and patients with myocardial infarct. BACKGROUND: Myocardial edema affects the T(2) relaxation time on CMR. Therefore, T(2)-mapping has been established to characterize edema at 1.5 T. A 3 T implementation designed for longitudinal studies and aimed at guiding and monitoring therapy remains to be implemented, thoroughly characterized, and evaluated in vivo. METHODS: A free-breathing navigator-gated radial CMR pulse sequence with an adiabatic T(2) preparation module and an empirical fitting equation for T(2) quantification was optimized using numerical simulations and was validated at 3 T in a phantom study. Its reproducibility for myocardial T(2) quantification was then ascertained in healthy volunteers and improved using an external reference phantom with known T(2). In a small cohort of patients with established myocardial infarction, the local T(2) value and extent of the edematous region were determined and compared with conventional T(2)-weighted CMR and x-ray coronary angiography, where available. RESULTS: The numerical simulations and phantom study demonstrated that the empirical fitting equation is significantly more accurate for T(2) quantification than that for the more conventional exponential decay. The volunteer study consistently demonstrated a reproducibility error as low as 2 ± 1% using the external reference phantom and an average myocardial T(2) of 38.5 ± 4.5 ms. Intraobserver and interobserver variability in the volunteers were -0.04 ± 0.89 ms (p = 0.86) and -0.23 ± 0.91 ms (p = 0.87), respectively. In the infarction patients, the T(2) in edema was 62.4 ± 9.2 ms and was consistent with the x-ray angiographic findings. Simultaneously, the extent of the edematous region by T(2)-mapping correlated well with that from the T(2)-weighted images (r = 0.91). CONCLUSIONS: The new, well-characterized 3 T methodology enables robust and accurate cardiac T(2)-mapping at 3 T with high spatial resolution, while the addition of a reference phantom improves reproducibility. This technique may be well suited for longitudinal studies in patients with suspected or established heart disease.

Comparison of multislice computerized tomography angiography and digital subtraction angiography in the postoperative evaluation of patients with clipped aneurysms.

OBJECT: In this study the accuracy of multislice computerized tomography (MSCT) angiography in the postoperative examination of clip-occluded intracranial aneurysms was compared with that of intraarterial digital subtraction (DS) angiography METHODS: Forty-nine consecutive patients with 60 clipped aneurysms (41 of which had ruptured) were studied with the aid of postoperative MSCT and DS angiography. Both types of radiological studies were reviewed independently by two observers to assess the quality of the images, the artifacts left by the clips, the completeness of aneurysm occlusion, the patency of the parent vessel, and the duration and cost of the examination. The quality of MSCT angiography was good in 42 patients (86%). Poor-quality MSCT angiograms (14%) were a result of the late acquisition of images in three patients and the presence of clip or motion artifacts in four. Occlusion of the aneurysm on good-quality MSCT angiograms was confirmed in all but two patients in whom a small (2-mm) remnant was confirmed on DS angiograms. In one patient, occlusion of a parent vessel was seen on DS angiograms but missed on MSCT angiograms. The sensitivity and specificity for detecting neck remnants on MSCT angiography were both 100%, and the sensitivity and specificity for evaluating vessel patency were 80 and 100%, respectively (95% confidence interval 29.2-100%). Interobserver agreements were 0.765 and 0.86, respectively. The mean duration of the examination was 13 minutes for MSCT angiography and 75 minutes for DS angiography (p < 0.05). Multislice CT angiography was highly cost effective (p < 0.01). CONCLUSIONS: Current-generation MSCT angiography is an accurate noninvasive tool used for assessment of clipped aneurysms in the anterior circulation. Its high sensitivity and low cost warrant its use for postoperative routine control examinations following clip placement on an aneurysm. Digital subtraction angiography must be performed if the interpretation of MSCT angiograms is doubtful or if the aneurysm is located in the posterior circulation.

Coronary magnetic resonance imaging.

Coronary magnetic resonance imaging is a powerful non-invasive technique for the combined assessment of coronary artery anatomy and function. In the present review article, challenges in coronary artery imaging are discussed and results obtained in both healthy volunteers and patients with cardiovascular disease are presented. This includes a short overview of coronary artery vessel lumen and wall imaging, contrast agents, permeability of the coronary vessel wall, high-field imaging and imaging of endothelial function.

Evaluation of monoenergetic imaging to reduce metallic instrumentation artifacts in computed tomography of the cervical spine.

OBJECT Monoenergetic imaging with dual-energy CT has been proposed to reduce metallic artifacts in comparison with conventional polychromatic CT. The purpose of this study is to systematically evaluate and define the optimal dual-energy CT imaging parameters for specific cervical spinal implant alloy compositions. METHODS Spinal fixation rods of cobalt-chromium or titanium alloy inserted into the cervical spine section of an Alderson Rando anthropomorphic phantom were imaged ex vivo with fast-kilovoltage switching CT at 80 and 140 peak kV. The collimation width and field of view were varied between 20 and 40 mm and medium to large, respectively. Extrapolated monoenergetic images were generated at 70, 90, 110, and 130 kiloelectron volts (keV). The standard deviation of voxel intensities along a circular line profile around the spine was used as an index of the magnitude of metallic artifact. RESULTS The metallic artifact was more conspicuous around the fixation rods made of cobalt-chromium than those of titanium alloy. The magnitude of metallic artifact seen with titanium fixation rods was minimized at monoenergies of 90 keV and higher, using a collimation width of 20 mm and large field of view. The magnitude of metallic artifact with cobalt-chromium fixation rods was minimized at monoenergies of 110 keV and higher; collimation width or field of view had no effect. CONCLUSIONS Optimization of acquisition settings used with monoenergetic CT studies might yield reduced metallic artifacts.

Respiratory self-navigated postcontrast whole-heart coronary MR angiography: initial experience in patients.

PURPOSE: To assess the diagnostic performance of respiratory self-navigation for whole-heart coronary magnetic resonance (MR) angiography in a patient cohort referred for diagnostic cardiac MR imaging. MATERIALS AND METHODS: Written informed consent was obtained from all participants for this institutional review board-approved study. Self-navigated coronary MR angiography was performed after administration of a contrast agent in 78 patients (mean age, 48.5 years ± 20.7 [standard deviation]; 53 male patients) referred for cardiac MR imaging because of coronary artery disease (n = 40), cardiomyopathy (n = 14), congenital anomaly (n = 17), or "other" (n = 7). Examination duration was recorded, and the image quality for each coronary segment was assessed with consensus reading. Vessel sharpness, length, and diameter were measured. Quantitative values in proximal, middle, and distal segments were compared by using analysis of variance and t tests. A double-blinded comparison with the results of x-ray angiography was performed when such results were available. RESULTS: When patients with different indications for cardiac MR imaging were examined with self-navigated postcontrast coronary MR angiography, whole-heart data sets with 1.15-mm isotropic spatial resolution were acquired in an average of 7.38 minutes ± 1.85. The main and proximal coronary segments could be visualized in 92.3% of cases, while the middle and distal segments could be visualized in 84.0% and 55.8% of cases, respectively. Subjective scores and vessel sharpness were significantly higher in the proximal segments than in the middle and distal segments (P < .05). Anomalies of the coronary arteries could be confirmed or excluded in all cases. Per-vessel sensitivity and specificity for stenosis detection were 64.7% and 85.0%, respectively, in the 31 patients for whom reference standard x-ray coronary angiography results were available. CONCLUSION: The self-navigated coronary MR angiography sequence shows promise for coronary imaging. However, technical improvements are needed to improve image quality, especially in the more distal coronary segments.

Regulation of the vascular gap junctions in a mouse model of intimal hyperplasia

Objective: Intimal hyperplasia (IH) is one of the leading causes of failure¦after vascular interventions. It involves the proliferation of smooth muscle¦cells (SMCs) and the production of extracellular fibrous matrix. Gap junctional¦communication, mediated by membrane connexins (Cx), participates to the¦control of proliferation and migration. In human and mice vessels, endothelial¦cells (ECs) express Cx37, Cx40 and Cx43, whereas SMCs are coupled by Cx43.¦We previously reported that Cx43 was increased in the SMCs of a human vein¦during the development of IH.¦In our experimental model of mice carotid artery ligation (CAL), luminal¦narrowing occurred by SMCs-rich neointima after 2-4 weeks of ligation.¦This experimental model of mice allows us to decipher the regulation of the¦cardiovascular connexins in the mouse.¦Methods: C57BL/6 mice were anesthetized and the left common carotid artery¦was dissected through a neck incision and ligated near the carotid bifurcation.¦The mice were then euthanized at 7, 14 and 28 days. Morphometric analyses¦were then performed with measurements of total area, lumen and intimal area¦and media thickness. Western blots, immunocytochemistry and quantitative¦RT-PCR were performed for Cx43, Cx40 and Cx37.¦Results: All animals recovered with no symptom of stroke. Morphometric¦analysis demonstrated that carotid ligation resulted in an initial increase (after¦7 days) of the total vessel area followed by its reduction (after 28 days). This¦phenomena was associated with a progressive increase in the intimal area and a¦consecutive decrease of the lumen. The media thickness was also increased after¦14 and 28 days. This neointima formation was associated to a marked increase¦in the expression of Cx43 at both protein and RNA levels. Concomitantly,¦Cx40 and Cx37 protein expression were reduced in the endothelium. This was¦confirmed by en face analyses showing reduced Cx37 and Cx40 levels in the¦endothelial cells covering the lesion.¦Conclusion: This study assessed the regulation of the cardiovascular connexins¦in the development of IH. This model will allow us to characterize the¦involvement of gap junctions in the IH. In turn, this understanding is¦instrumental for the development of new therapeutical tools, as well as for¦the evaluation of the effects of drugs and gene therapies of this disease for which¦there is no efficient therapy available.

On-pump beating heart coronary surgery for high risk patients requiring emergency multiple coronary artery bypass grafting.

BACKGROUND: Cardiopulmonary bypass (CPB) with aortic cross-clamping and cardioplegic arrest remains the method of choice for patients requiring standard myocardial revascularization. Therefore, very high-risk patients presenting with acute coronary syndrome, unstable angina, onset of cardiac decompensation and requiring emergency multiple myocardial revascularization, can have a poor outcome. The on-pump beating heart technique can reduce the mortality and the morbidity in such a selected group of patients and this report describes our clinical experience. METHODS: Out of 290 patients operated for CABG from January 2005 to January 2006, 25 (8.6%) selected high-risk patients suffering from life threatening coronary syndrome (mean age 69 +/- 7 years) and requiring emergency multiple myocardial revascularization, underwent on-pump beating heart surgery. The mean pre-operative left ventricle ejection fraction (LVEF) was 27 +/- 8%. The majority of them (88%) suffered of tri-vessel coronary disease and 6 (24%) had a left main stump disease. Nine patients (35%) were on severe cardiac failure and seven among them (28%) received a pre-operative intra-aortic balloon pump. The pre-operative EuroScore rate was equal or above 8 in 18 patients (73%). RESULTS: All patients underwent on-pump-beating heart coronary revascularization. The mean number of graft/patient was 2.9 +/- 0.6 and the internal mammary artery was used in 23 patients (92%). The mean CPB time was 84 +/- 19 minutes. Two patients died during the recovery stay in the intensive care unit, and there were no postoperative myocardial infarctions between the survivors. Eight patients suffered of transitorily renal failure and 1 patient developed a sternal wound infection. The mean hospital stay was 12 +/- 7 days. The follow-up was complete for all 23 patients survived at surgery and the mean follow-up time was 14 +/- 5 months. One patient died during the follow-up for cardiac arrest and 2 patients required an implantable cardiac defibrillator. One year after surgery they all had a standard trans-thoracic echocardiogram showing a mean LVEF rate of 36 +/- 11.8%. CONCLUSION: Standard on-pump arrested heart coronary surgery has higher mortality and morbidity in emergencies. The on-pump beating heart myocardial revascularization seems to be a valid alternative for the restricted and selected cohort of patients suffering from life threatening coronary syndrome and requiring multiple emergency CABG.

The renin-angiotensin system and arterial wall behavior.

To assess the behavior of the arterial wall in hypertensive patients, we developed a noninvasive ultrasonic device. Simultaneous recordings of internal diameter and blood pressure over the whole cardiac cycle are used to establish compliance-pressure curves. Blood pressure, which is a co-determinant of compliance, is thus taken into account. This method allows one to compare arteries from patients with different blood pressures. Arterial compliance and distensibility were first investigated in healthy young volunteers administered either lisinopril (20 mg), atenolol (100 mg) or nitrendipine (20 mg) once a day. After 8 days of treatment, only lisinopril was found to increase arterial compliance. Subsequently, we compared arterial diameter- and distensibility-pressure curves from newly diagnosed and untreated hypertensive patients with those of matched normotensive control patients. Diameter-pressure curves did not differ significantly between the groups and distensibility was not reduced. Similar findings were later obtained in an animal model, when mechanical properties of carotid arteries were compared between spontaneously hypertensive rats and normotensive counterparts (Wistar-Kyoto rats). These results, although interesting by providing noninvasive information on the elastic response of the wall, call for further development of the technique to be able to measure arterial wall thickness. Stress-strain relationship could ultimately be established to thoroughly characterize physical properties of blood vessel walls.

Myocardial angiogenesis induction with bone protein derived growth factors (animal experiment).

Myocardial angiogenesis induction with vascular growth factors constitutes a potential strategy for patients whose coronary artery disease is refractory to conventional treatment. The importance of angiogenesis in bone formation has led to the development of growth factors derived from bovine bone protein. Twelve pigs (mean weight, 73 +/- 3 kg) were chosen for the study. In the first group (n = 6, growth factor group) five 100 micrograms boluses of growth factors derived from bovine bone protein, diluted in Povidone 5%, were injected in the lateral wall of the left ventricle. In the second group (n = 6, control group), the same operation was performed but only the diluting agent was injected. All the animals were sacrificed after 28 days and the vascular density of the left lateral wall (expressed as the number of vascular structures per mm2) as well as the area of blood vessel profiles per myocardial area analysed were determined histologically with a computerised system. The growth factor group had a capillary density which was significantly higher than that of the control group: 12.6 +/- 0.9/mm2 vs 4.8 +/- 0.5/mm2 (p < 0.01). The same holds true for the arteriolar density: 1 +/- 0.2/mm2 vs 0.3 +/- 0.1/mm2 (p < 0.01). The surface ratios of blood vessel profiles per myocardial area were 4900 +/- 800 micron 2/mm2 and 1550 +/- 400 micron 2/mm2 (p < 0.01) respectively. In this experimental model, bovine bone protein derived growth factors induce a significant neovascularisation in healthy myocardium, and appear therefore as promising candidates for therapeutic angiogenesis.

Two cases of Takayasu's arteritis occurring under anti-TNF therapy.

Takayasu's arteritis is a granulomatous, large vessel vasculitis that affects the aorta, its major branches and the pulmonary arteries. Compelling evidence exists to support the notion that Takayasu's arteritis is a T-cell mediated process and that tumor necrosis factor alpha (TNFa) is an important factor in the pathogenesis of this disease. Moreover, encouraging results from recent studies support the use of anti-TNFa therapy for relapsing or resistant cases of Takayasu's arteritis. Here, however, we describe the case of two patients: one with seropositive rheumatoid arthritis, the other with HLA-B27 negative spondylarthropathy, who developed Takayasu's arteritis during treatment with TNFa inhibitors (adalimumab and golimumab respectively). This is the first report of Takayasu's arteritis in rheumatic patients under TNFa blocking agents which suggests the presence of different pathogenetic mechanism in a subgroup of patients with Takayasu's arteritis, as well as a potential role of TNFa blockers as triggers of this disease in some cases.

The effect of standard and high-fluence corneal cross-linking (CXL) on cornea and limbus.

PURPOSE: When treating peripheral ectatic disease-like pellucid marginal degeneration (PMD), corneal cross-linking with UV-A and riboflavin (CXL) must be applied eccentrically to the periphery of the lower cornea, partly irradiating the corneal limbus. Here, we investigated the effect of standard and double-standard fluence corneal cross-linking with riboflavin and UV-A (CXL) on cornea and corneal limbus in the rabbit eye in vivo. METHODS: Epithelium-off CXL was performed in male New Zealand White rabbits with two irradiation diameters (7 mm central cornea, 13 mm cornea and limbus), using standard fluence (5.4 J/cm(2)) and double-standard fluence (10.8 J/cm(2)) settings. Controls were subjected to epithelial removal and riboflavin instillation, but were not irradiated with UV-A. Following CXL, animals were examined daily until complete closure of the epithelium, and at 7, 14, 21, and 28 days. Animals were killed and a corneoscleral button was excised and processed for light microscopy and immunohistochemistry. RESULTS: For both irradiation diameters and fluences tested, no signs of endothelial damage or limbal vessel thrombosis were observed, and time to re-epithelialization was similar to untreated controls. Histological and immunohistochemical analysis revealed no differences in the p63 putative stem cell marker expression pattern. CONCLUSIONS: Even when using fluence twice as high as the one used in current clinical CXL settings, circumferential UV-A irradiation of the corneal limbus does not alter the regenerative capacity of the limbal epithelial cells, and the expression pattern of the putative stem cell marker p63 remains unchanged. This suggests that eccentric CXL may be performed safely in PMD.