Tudor C. Poerner

Detection of Coronary Microembolization by Doppler Ultrasound in Patients With Stable Angina Pectoris Undergoing Elective Percutaneous Coronary Interventions

Background— Intracoronary Doppler guidewires can be used for real-time detection and quantification of microembolism during percutaneous coronary interventions (PCIs). We investigated whether the frequency of Doppler-detected microembolism is related to the incidence of myonecrosis during elective PCI. Methods and Results— The study population included 52 consecutive patients (aged 64±10 years; 36 men, 16 women) with coronary artery disease who underwent elective PCI of a single-vessel stenosis. Using intracoronary Doppler ultrasound, we compared the frequency of microembolism during PCI in 22 patients with periprocedural non–ST-segment elevation myocardial infarctions (pNSTEMI) and 30 patients without pNSTEMI. The 2 groups were comparable with regard to their clinical and procedural characteristics. In the group with pNSTEMI, the total number of coronary microemboli after PCI (27±10 versus 16±8, P<0.001) was higher than in the group without pNSTEMI. Although high-sensitivity C-reactive protein plasma levels were similar before PCI (2.9±2.2 versus 3.4±1.7 mg/L, P=NS), they were higher in the group with pNSTEMI after PCI (12.6±10.4 versus 6.1±5.1 mg/L, P<0.05). Microembolic count independently correlated to postprocedural cardiac troponin I elevation (r=0.565, P<0.001), coronary flow velocity reserve (r=−0.506, P<0.001), and baseline average peak velocity (r=0.499, P<0.001). Conclusions— Patients with pNSTEMI had a significantly higher frequency of coronary microembolization during PCI, and their systemic inflammatory response and microvascular impairment after PCI were more pronounced. Intracoronary Doppler ultrasound provides evidence that pNSTEMI in patients undergoing elective PCI is caused by microembolization during the procedure.

Influence of Nebivolol and Metoprolol on Inflammatory Mediators in Human Coronary Endothelial or Smooth Muscle Cells. Effects on Neointima Formation After Balloon Denudation in Carotid Arteries of Rats Treated with Nebivolol

Objective and Background: Inflammation plays a critical role in all stages of atherogenesis. Proliferating vascular smooth muscle cells (SMC) and endothelial cells (EC) enhancing the inflammatory response, both contribute to the progression of atherosclerosis. Anti-proliferative, anti-inflammatory and anti-oxidative therapy seems to be a promising therapeutic strategy. The aim of this study was to assess the anti-proliferative and anti-inflammatory effect of the β-blocker nebivolol in comparison to metoprolol in vitro and to find out whether nebivolol inhibits neointima formation in vivo. Methods and Results: Real-time-RT-PCR revealed a decrease in VCAM-1, ICAM-1, PDGF-B, E-selectin and P-selectin mRNA expression in human coronary artery EC and SMC incubated with nebivolol for 72 hours while metoprolol did not have this effect. Nebivolol reduced MCP-1 and PDGF-BB protein in the culture supernatant of SMC and EC, respectively. Sprague-Dawley rats were treated with nebivolol for 0 or 35 days before and 28 days after carotid balloon injury. Immunohistological analyses showed that pre-treatment with nebivolol was associated with a decreased number of SMC layers and macrophages and an increased lumen area at the site of the arterial injury. The intima area was reduced by 43% after pre-treatment. Conclusion: We found that nebivolol reduced the expression of proinflammatory genes in endothelial cells and vascular smooth muscle cells in vitro whereas metoprolol did not. In vivo, nebivolol inhibited neointima formation by reducing SMC proliferation and macrophage accumulation.

Exercise tissue Doppler echocardiography with strain rate imaging in healthy young individuals: feasibility, normal values and reproducibility

Purpose of the studyThe study was done to determine the clinical feasibility and reproducibility of tissue Doppler echocardiography (TDE) with strain rate imaging (SRI) at rest and under physical exercise in healthy young individuals and to report normal values for parameters of regional myocardial function under exercise.MethodsForty-five young volunteers (age 9–29xa0years) underwent echocardiography with TDE/SRI at rest and during a bicycle exercise test (2xa0W/kg body weight).ResultsVelocities could be obtained in 93% of segments, whereas strain rate was measurable at least in 80% of segments. Inter- and intraobserver variability for measurement of velocities under exercise was 14% and 9%, respectively for strain rate 28% and 20%. Except for peak strain, values for all other parameters were higher during exercise with the clearest response in the left lateral and the right ventricular wall.Conclusions(1) Tissue Doppler with strain rate imaging is a practical and robust method for assessment of regional function of both ventricles under exercise. (2) Systolic motion, local myocardial relaxation and contractility increased significantly under physical exercise. These normal values obtained from healthy young subjects can serve as a reference database for further clinical studies.

First use of a novel plug-and-play percutaneous circulatory assist device for high-risk coronary angioplasty

Objectives: Novel circulatory assist devices provide hemodynamic stability in high risk coronary interventions. They ensure sufficient organ perfusion during transfer in case of procedural failure or cardiogenic arrest. We describe the first human use of a novel plug-and-play circulatory assist device for high risk coronary angioplasty. Methods: An 84 year old lady suffered syncope with complex fracture of the left forearm. Her syncope was related to a subtotal stenosis of the left main coronary artery associated with an acute myocardial infarction. Additional risk factors were previous cardiac surgery, pulmonary disease, diabetes mellitus, and renal insufficiency. Coronary angiography revealed stenosis of both coronary ostia. The emergency assist device LIFEBRIDGE was connected with the patients circulation by percutaneous cannulation (15F and 17F) of the femoral artery and vein. Results: Stent implantation was performed in both coronary ostia by Judkins technique. The cannulas were removed two hours after the intervention by local compression. Osteosynthesis of the left radius and ulna was performed five days later under regional anesthesia. The patient was discharged without any complains on day 10. Conclusion: This case illustrates the safe and easy use of a novel plug-and-play percutaneous circulatory assist device for high risk interventions. It may be recommended for use in emergency situations.

Endothelial progenitor cells and plaque burden in stented coronary artery segments: an optical coherence tomography study six months after elective PCI

BackgroundEndothelial progenitor cells (EPC) are involved in neovascularization and endothelial integrity. They might be protective in atherosclerosis. Optical coherence tomography (OCT) is a precise intracoronary imaging modality that allows assessment of subintimal plaque development. We evaluated the influence of EPC on coronary plaque burden in stable disease and implemented a novel computational plaque analysis algorithm using OCT.MethodsForty-three patients (69.8% males, 69.6xa0±xa07.7xa0years) were investigated by OCT during re-angiography 6xa0months after elective stent implantation. Different subpopulations of EPCs were identified by flow cytometry according to their co-expression of antigens (CD34+, CD133+, kinase domain receptor, KDR+). An algorithm was applied to calculate the underlying total plaque burden of the stented segments from OCT images. Plaque morphology was assessed according to international consensus in OCT imaging.ResultsA cumulative sub-strut plaque volume of 10.87xa0±xa012.7xa0mm3 and a sub-stent plaque area of 16.23xa0±xa017.0xa0mm2 were found within the stented vessel segments with no significant differences between different stent types. All EPC subpopulations (mean of EPC levels: CD34+/CD133+: 2.66xa0±xa02.0%; CD34+/KDR+: 7.50xa0±xa05.0%; CD34+/CD133+/KDR+: 1.12xa0±xa01.0%) inversely correlated with the identified underlying total plaque volume and plaque area (pxa0≤xa00.012).ConclusionsThis novel analysis algorithm allows for the first time comprehensive quantification of coronary plaque burden by OCT and illustration as spread out vessel charts. Increased EPC levels are associated with less sub-stent coronary plaque burden which adds to previous findings of their protective role in atherosclerosis.

Invasive therapeutic strategies in acute heart failure complicating coronary artery disease: effectiveness and boundaries

ZusammenfassungEine häufige Ursache der akuten Herzinsuffizienz ist nach wie vor der akute Myokardinfarkt als Folge der koronaren Atherothrombose. In diesem Übersichtsartikel werden die spezifischen Merkmale und die modernen Behandlungsstrategien bei kardiogenem Schock infolge eines akuten Myokardinfarkts aufgrund der aktuellen Datenlage abgehandelt, wobei besonderes Augenmerk auf die Wertigkeit der Revaskularisationsmaßnahmen und der mechanischen Kreislaufunterstützungssysteme gerichtet wird.AbstractAcute heart failure and especially its most severe form, the cardiogenic shock, remain the final common pathway to death in a substantial number of patients with acute myocardial infarction (MI). Several studies demonstrated that mechanical reperfusion of occluded coronary arteries by percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery improves survival in patients with acute MI and cardiogenic shock. There is strong evidence that intraaortic balloon pump (IABP) support and ventricular assist devices can stabilize hemodynamics in these patients so that revascularization procedures can be safely performed. This article provides an overview of the therapeutic strategies for acute MI with cardiogenic shock, with focus on the role and particularities of different devices used as mechanical circulatory support in these patients.

Quantification of mitral regurgitation during percutaneous mitral valve repair: added value of simultaneous hemodynamic and 3D echocardiographic assessment

The objective of this study was to investigate the usefulness of intraprocedural hemodynamic monitoring for MR evaluation during pMRV. Assessment of mitral regurgitation (MR) during percutaneous mitral valve repair (pMVR) procedure is challenging. 3D color Doppler allows exact quantification of MR, but is technically demanding. Sixty patients with moderate to severe MR (14 with structural and 46 functional MR) were included in the study. Intraprocedural pressure curves were continuously obtained in the left atrium (LA) and left ventricle (LV). Transesophageal echocardiography was performed using 3D color Doppler derived mean vena contracta area (VCAmean) and mitral regurgitation volume (RegVol) to quantify MR severity before and after each clip implantation. In the entire patient group, strongest correlations were observed firstly between VCA and the raise of the ascending limb of the left atrial V pressure wave (Vascend; ru2009=u20090.58, pu2009<u20090.001) and secondly between the difference of peak V wave pressure and mean LA pressure divided by systolic LV pressure [(Vpeaku2009−u2009LAmean)u2009−u2009LVsystole; ru2009=u20090.53, pu2009<u20090.001]. In patients with structural MR, the highest area under the ROC curve for prediction of mild MR (VCAmean < 0.2 cm² and RegVolu2009<u200930xa0ml) after clip implantation was found for Vascend (AUC 0.89, pu2009<u20090.001) whereas in functional MR calculation of (Vpeaku2009−u2009LAmean)u2009−u2009LVsystole showed the highest predictive value (AUC 0.69, pu2009=u20090.003). Invasive pressure monitoring can give a direct feedback with regard to the success of clip placement during pMVR.

Möglichkeiten und Grenzen der interventionellen Therapie bei akuter Herzinsuffizienz bei koronarer Herzerkrankung

ZusammenfassungEine häufige Ursache der akuten Herzinsuffizienz ist nach wie vor der akute Myokardinfarkt als Folge der koronaren Atherothrombose. In diesem Übersichtsartikel werden die spezifischen Merkmale und die modernen Behandlungsstrategien bei kardiogenem Schock infolge eines akuten Myokardinfarkts aufgrund der aktuellen Datenlage abgehandelt, wobei besonderes Augenmerk auf die Wertigkeit der Revaskularisationsmaßnahmen und der mechanischen Kreislaufunterstützungssysteme gerichtet wird.AbstractAcute heart failure and especially its most severe form, the cardiogenic shock, remain the final common pathway to death in a substantial number of patients with acute myocardial infarction (MI). Several studies demonstrated that mechanical reperfusion of occluded coronary arteries by percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery improves survival in patients with acute MI and cardiogenic shock. There is strong evidence that intraaortic balloon pump (IABP) support and ventricular assist devices can stabilize hemodynamics in these patients so that revascularization procedures can be safely performed. This article provides an overview of the therapeutic strategies for acute MI with cardiogenic shock, with focus on the role and particularities of different devices used as mechanical circulatory support in these patients.

Vena contracta area for severity grading in functional and degenerative mitral regurgitation: a transoesophageal 3D colour Doppler analysis in 500 patients

AimsnVena contracta area (VCA3D), derived by 3D colour Doppler echocardiography, has already been validated against cardiac magnetic resonance imaging, but the number of clinical studies to define cut-off values for grading of mitral regurgitation (MR) is limited. Aim of the study was to assess VCA3D in a large population of patients with functional (FMR) and degenerative MR (DMR).nnnMethods and resultsnTransoesophageal echocardiography was performed in 500 patients with MR. The following 2D parameters were assessed for grading of MR: vena contracta width, effective regurgitant orifice area (EROAPISA), and regurgitation volume (RVPISA). VCA3D and the corresponding regurgitation volume (RVVCA) were quantified using 3D colour Doppler loop and CW Doppler tracing of the regurgitant jet. In 104 patients a 3D dataset of the left ventricle (LV) and the left ventricular outflow tract (LVOT) was acquired. As a reference method, regurgitation volume (RV3D) was calculated as difference between LV overall and LVOT stroke volumes. For prediction of severe MR, VCA3D yielded higher values of area under the ROC curve compared to EROAPISA (overall patient group 0.98 for VCA3D vs. 0.90 for EROAPISA, Pu2009<u20090.001; FMR group 0.97 for VCA3D vs. 0.92 for EROAPISA, Pu2009=u20090.002). RVVCA correlated closer with RV3D compared to RVPISA (ru2009=u20090.96 for RVPISA, ru2009=u20090.79 for RVPISA).nnnConclusionnThis study delivers cut-off values for VCA3D in patients with different types of MR. VCA3D is a robust parameter for quantification of MR, showing a good correlation with the reference method using 3D datasets of LV.

Development and characterization of an ex vivo arterial long-term proliferation model for restenosis research.

One of the main limitations of percutaneous coronary interventions is the restenosis, occurring in small-diameter arteries, and efforts are high to find improved intracoronary devices to prevent in-stent-restenosis. Aim of this study was to produce a new in vitro test platform for restenosis research, suitable for long-term cell proliferation and migration studies in stented vessels. Fresh segments of porcine coronary arteries were obtained for decellularization and were then reseeded with human coronary artery endothelial (HCAEC) and human coronary artery smooth muscle cells (HCASMC). Subsequently, bare metal stents (BMS) and drug eluting stents (DES), respectively, were implanted and the segments were reseeded with HCAEC and HCASMC for up to three months. The stented segments were examined at time zero and after 2, 4, 6, 8 and 12 weeks by histochemical and immunohistochemical characterization and the reseeded areas before and after stent implantation were measured. We have found that cells formed multiple layers after three months, and the detection with both CD31 and a-smooth muscle actin specific antibodies showed that HCAEC and HCASMC are adherent and growing in several layers. Furthermore, we could show a significantly smaller proliferation area in DES (70% ± 3.5%), compared to BMS (17% ± 2.3%). These data are similar to animal and human studies. Therefore, this vessel model might appear as an initial benchmark for testing new anti-proliferative endovascular therapies and consequently helps to reduce animal experiments in this research area.