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

BACKGROUND: Endothelial 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. METHODS: Forty-three patients (69.8% males, 69.6 ± 7.7 years) were investigated by OCT during re-angiography 6 months 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. RESULTS: A cumulative sub-strut plaque volume of 10.87 ± 12.7 mm3 and a sub-stent plaque area of 16.23 ± 17.0 mm2 were found within the stented vessel segments with no significant differences between different stent types. All EPC subpopulations (mean of EPC levels: CD34+/CD133+: 2.66 ± 2.0%; CD34+/KDR+: 7.50 ± 5.0%; CD34+/CD133+/KDR+: 1.12 ± 1.0%) inversely correlated with the identified underlying total plaque volume and plaque area (p ≤ 0.012). CONCLUSIONS: This 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.

Microembolization and myonecrosis during elective percutaneous coronary interventions in diabetic patients: an intracoronary Doppler ultrasound study with 2-year clinical follow-up.

Elevation of cardiac troponin I (cTnI) is a well-known complication after percutaneous coronary interventions (PCI). The aims of this study were to quantify the extent of coronary microembolization during elective PCI, to identify predisposing anatomical and procedural factors, and to evaluate its impact on long-term outcome in diabetic patients with a high cardiovascular risk. 48 patients (pts, median 66.7 years) with type 2 diabetes and coronary artery disease underwent elective PCI with stenting to treat single-vessel lesions. Real-time microembolization during PCI ("HITS") was detected by an intracoronary Doppler guide wire. Peak levels of cTnI were measured within 24 h after PCI. Pts were followed for 2 years to record major cardiac events (MACE: death, myocardial infarction, revascularization of target and non-target vessels). In 47 patients microemboli were detected during PCI. Nineteen patients showed pathologic cTnI elevation (0.13-28.9, median 0.39 µg/l). The amount of HITS correlated with cTnI levels (r = 0.43, p = 0.003), but not with other clinical or angiographic data. Within 2 years MACE were detected in 9 patients, who had significantly more microemboli (15.4 ± 11.8 vs. 28.2 ± 16.0 HITS; p = 0.009, OR 1.07; 95 % CI 1.011-1.13) during PCI. HITS >23, but not cTnI elevation, predicted later MACE (ROC analysis, p = 0.025). A high amount of microembolization during elective PCI in diabetic patients appears to be an indicator of greater atherosclerotic burden and accelerated coronary artery disease progression, associated with acute biomarker elevation and adverse long-term outcomes.

Echocardiographic evaluation of left ventricular filling pressures validated against an implantable left ventricular pressure monitoring system.

BACKGROUND: Aim of this study was to assess the ability of different echocardiographic indices to evaluate left ventricular (LV) filling pressures in patients with reduced LV function. METHODS: In 5 patients scheduled for aortocoronary bypass surgery, a telemetric intraventricular pressure sensor was implanted. Over 6 months, these patients underwent a total of 21 echocardiographic examinations with a simultaneous recording of left ventricular mean (LVMDP) and end-diastolic pressure (LVEDP). The following echocardiographic parameters were extracted from the transmitral flow profile: early (E) and late (A) diastolic flow velocity, deceleration time of the E-wave (DT) and the isovolumic relaxation time (IVRT). Early diastolic velocity of the mitral ring (E') was recorded using pulsed-wave tissue Doppler echocardiography. RESULTS: All patients were in NYHA class III and mean ejection fraction was 30%. E correlated only moderately with LVMDP (r =-0.60, P = 0.003), but revealed the highest area under the receiver operating characteristic curve for the prediction of an elevated LVMDP > 12 mmHg (AUC = 0.94, sensitivity of 92% and specificity of 86%, cut-off value 7.5 cm/s). E/A > 1 predicted LVEDP > 15 mmHg with a sensitivity of 87% and a specificity of 80%. E/E' was not correlated with LVMDP or LVEDP. CONCLUSION: Although linear correlation between echocardiographic parameters and diastolic LV pressures reached statistical significance, the correlation coefficients were low. However, in these patients with severely reduced LV function due to ischemic heart disease conventional echocardiographic parameters of transmitral flow showed higher predictive values for elevated LV filling pressures than E/E'.

Drug-Coated Balloons for Coronary Artery Disease: Third Report of the International DCB Consensus Group.

Although drug-eluting stents are still the default interventional treatment of coronary artery disease, drug-coated balloons (DCBs) represent a novel alternative therapeutic strategy in certain anatomic conditions. The effect of DCBs is based on the fast and homogenous transfer of antiproliferative drugs into the vessel wall during single balloon inflation by means of a lipophilic matrix without the use of permanent implants. Although their use is established for in-stent restenosis of both bare-metal and drug-eluting stents, recent randomized clinical data demonstrate a good efficacy and safety profile in de novo small-vessel disease and high bleeding risk. In addition, there are other emerging indications (e.g., bifurcation lesions, large-vessel disease, diabetes mellitus, acute coronary syndromes). Because the interaction among the different delivery balloon designs, doses, formulations, and release kinetics of the drugs used is important, there seems to be no "class effect" of DCBs. On the basis of the amount of recently published data, the International DCB Consensus Group provides this update of previous recommendations summarizing the historical background, technical considerations such as choice of device and implantation technique, possible indications, and future perspectives.

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.

Evaluation of the microcirculation during extracorporeal membrane-oxygenation.

Extracorporeal membrane oxygenation (ECMO) provides pulmonary and circulatory support in critically ill patients (Cardiopulmonary Resuscitation, Acute Respiratory Distress Syndrome, or low output syndrome). Hemodynamic parameters are used for evaluation of the macrocirculation, while the microcirculation is monitored by blood-lactate as a surrogate parameter. We evaluated the microcirculation by orthogonal polarization spectral imaging in a patient during ECMO support. This method was initially proposed to quantify changes of microcirculation in patients with septic shock. However, we were able to non-invasively monitor microcirculatory changes at the bedside during temporary intentional arrest of ECMO due to an exchange of the oxygenator. Using a computerized analyzation model, the flow after ECMO stop in vessels (10-100 microm) in the sublingual mucosa was acutely absent or intermittent, respectively. 120 s after restart, microflow was improved with new ECMO settings compared to baseline, while macrocirculation with a mean arterial pressure of 75 mmHg was present after 60 s. The application of orthogonal polarization spectral imaging might be a valuable technique for evaluation of the microcirculation during extracorporeal circulation. It is rapidly implementable, can be used in vivo, and no invasive probes are required.

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

Aims: Vena 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). Methods and results: Transoesophageal 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, P < 0.001; FMR group 0.97 for VCA3D vs. 0.92 for EROAPISA, P = 0.002). RVVCA correlated closer with RV3D compared to RVPISA (r = 0.96 for RVPISA, r = 0.79 for RVPISA). Conclusion: This 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.

Impact of mitral E/A ratio on the accuracy of different echocardiographic indices to estimate left ventricular end-diastolic pressure.

The objective was to determine the influence of left ventricular (LV) inflow pattern on the accuracy of different echocardiographic indices for estimation of LV end-diastolic pressure (LVEDP). Echocardiography with color tissue Doppler imaging (TDI) and LVEDP measurements using fluid-filled catheters were performed in 176 consecutive patients on the same day. Mitral peak diastolic velocities (E, A) and the difference in duration between pulmonary venous retrograde velocity and mitral A-velocity (PV(R)-A) were recorded by pulsed Doppler. Propagation velocity of the early mitral inflow (V(P)) was assessed using color M-mode. Early diastolic longitudinal (E'(lat)) and radial (E'(radial)) velocities of mitral annulus were measured by TDI. Area under ROC curve (AUC) for prediction of elevated LVEDP (> or =15 mm Hg) was computed for each parameter. For E/A > or =1 (98 patients, 46 with elevated LVEDP), the AUC values were: PV(R)-A: 0.914; E/E'(lat): 0.780; E/E'(radial): 0.729; E/V(P): 0.712 (p < 0.001). When E/A <1 (78 patients, 26 with elevated LVEDP), only PV(R)-A reached statistical significance (AUC = 0.893, p < 0.001). The conclusions were: PV(R)-A enabled the most accurate noninvasive estimation of LVEDP irrespective of LV filling profile and combined indices E/V(P), E/E'(lat) and E/E'(radial) represent more feasible alternatives for patients with mitral E/A-1.

Fractional flow reserve-guided coronary angioplasty using paclitaxel-coated balloons without stent implantation: feasibility, safety and 6-month results by angiography and optical coherence tomography.

BACKGROUND: Percutaneous coronary interventions (PCI) with drug-coated balloons (DCB) might be a promising trade-off between balloon angioplasty and drug-eluting stents, since DCB inhibit neointimal proliferation and limit duration of dual antiplatelet therapy. We investigated the safety, feasibility, and 6-month results of fractional flow reserve (FFR)-guided use of the paclitaxel-coated SeQuent Please® balloon without stenting for elective PCI of de novo lesions. METHODS AND RESULTS: In 46 patients (54 lesions) with stable symptomatic coronary artery disease (CAD), a FFR-guided POBA (plain old balloon angioplasty) was performed. In case of a sufficient POBA result with residual stenosis < 40 %, FFR > 0.8 and no severe dissection, the target lesion was finally dilated using the DCB. Quantitative coronary angiography (QCA) was performed before and after the index procedure and at 6-month follow-up (f/u) to calculate late lumen loss (LLL) and net luminal gain (NLG). Optical coherence tomography (OCT) was performed at f/u to assess vascular remodeling. DCB-only treatment was applied to 43 patients (51 lesions), while 3 patients (3 lesions) needed provisional stenting. Invasive f/u was completed in 39 patients (47 lesions). At the stenotic site, the lumen diameter showed a trend toward progressive increase at f/u (LLL: -0.13 ± 0.44 mm, n.s.; NLG: 1.10 ± 0.53 mm, p < 0.001) without aneurysm formation or restenosis after DCB-only treatment. CONCLUSIONS: FFR-guided DCB-only PCI of de novo lesions appeared feasible and safe in stable CAD with clopidogrel discontinuation after 4 weeks, showing a trend toward positive vessel remodeling without lumen loss at 6 months. Clinical trial registration http://www.clinicaltrials.gov . Unique identifier: NCT02120859.

ST-segment Elevation Following Cardioversion of Atrial Fibrillation in the Emergency Department: Unmasked Myocardial Infarction due to Left Main Coronary Artery Plaque Rupture or Unspecific Finding?

Atrial fibrillation (AF) is a frequent reason for emergency department visits. According to current guidelines either rate- or rhythm-control are acceptable therapeutic options in such situations. In this report, we present the complicated clinical course of a patient with AF and a rapid ventricular response. Because of paroxysmal AF, the patient was on chronic oral anticoagulation therapy with warfarin. Pharmacological treatment was ineffective to control ventricular rate, and immediate synchronized electrical cardioversion was performed. One hour later, the patient complained of chest pain in combination with marked ST-segment elevation in the anterior leads. Cardiac catheterization with optical coherence tomography disclosed plaque rupture in the left main coronary artery without other significant stenosis. Stent implantation was performed successfully. During the course of the hospital stay, the patient remained asymptomatic and the ST-segment elevations resolved. However, despite treatment with amiodarone it was not possible to keep the patient permanently in sinus rhythm. Therefore, a biventricular pacemaker was implanted and AV node ablation performed.

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; r = 0.58, p < 0.001) and secondly between the difference of peak V wave pressure and mean LA pressure divided by systolic LV pressure [(Vpeak - LAmean) - LVsystole; r = 0.53, p < 0.001]. In patients with structural MR, the highest area under the ROC curve for prediction of mild MR (VCAmean < 0.2 cm² and RegVol < 30 ml) after clip implantation was found for Vascend (AUC 0.89, p < 0.001) whereas in functional MR calculation of (Vpeak - LAmean) - LVsystole showed the highest predictive value (AUC 0.69, p = 0.003). Invasive pressure monitoring can give a direct feedback with regard to the success of clip placement during pMVR.

Side branch occlusion after coronary stent implantation in patients presenting with ST-elevation myocardial infarction: clinical impact and angiographic predictors.

BACKGROUND: The aim of this study was to assess the incidence and clinical outcome of the occlusion of major (> 1 mm) side branches following coronary stenting in patients undergoing percutaneous coronary intervention for acute ST-elevation myocardial infarction (STEMI). METHODS: Among 276 consecutive patients presenting with STEMI, we found 80 patients (29%) with 101 stent-covered side branches. Clinical data and quantitative angiographic analysis were evaluated. Angiographic follow-up was available in 56 (70%) patients, and clinical follow-up could be completed in all patients. RESULTS: Acute side branch occlusion after stent implantation (SBO) was observed in 10 (12.5%) patients involving 11 (10.9%) side branches. Predictors for SBO were: (1) reference side branch diameter at baseline < or = 1.4 mm; (2) ostial side branch stenosis > 50%; and (3) minimal side branch diameter at baseline < or = 0.6 mm. During hospitalization, in the SBO group, 2 patients died in cardiogenic shock and 1 underwent bypass surgery; no events were causally related to SBO. During long-term follow-up, 1 patient with SBO developed repeat MI as opposed to 7 patients in the non-SBO group who developed major adverse cardiac events (1 death, 6 repeat revascularizations). CONCLUSIONS: The presence of a side branch originating from the target lesion in patients undergoing coronary stenting for acute STEMI is a frequent observation (29%) and is associated with a low incidence of side branch occlusion. Major predictors for SBO are the side branch size and the presence of an ostial side branch stenosis.

A novel polymer-free ciglitazone-coated vascular stent: in vivo and ex vivo analysis of stent endothelialization in a rabbit iliac artery model.

AIM: Peroxisome proliferator-activated receptor-gamma (PPARg) agonists have known pleiotropic cardiovascular effects with favourable properties in vascular remodeling, and specifically in suppression of vascular smooth muscle cell proliferation. A novel vascular stent coating using the PPARg ligand ciglitazone (CCS) was investigated regarding its effects on endothelialization after 7 and 28 days. METHODS: Microporous bare metal stents (BMS) were coated with ciglitazone by ultrasonic flux with a load of 255 µg ciglitazone/stent. SixteenNew Zealand white rabbits, fed a with high cholesterol diet, underwent stent implantation in both iliac arteries. Everolimus-eluting stents (EES) and BMS were comparators. Histology (CD 31 immunostaining, confocal and scanning electron microscopy, morphometry) was performed after 7 and 28 days and by OCT (optical coherence tomography) in vivo after 28 days. RESULTS: Microscopy showed comparable results with near complete endothelialization in CCS and BMS (%CD31 above stent struts after 7 days: 67.92±36.35 vs. 84.48±23.86; p = 0.55; endothel % above stent struts: 77.22±27.9 vs. 83.89±27.91; p = 0.78). EES were less endothelialized with minimal fibrin deposition, not found in BMS and CCS (% CD 31 above struts after 28 days, BMS: 100.0±0.0 vs. EES: 95.9±3.57 vs. CCS: 100.0±0.0; p = 0.0292). OCT revealed no uncovered struts in all stents after 28 days. CONCLUSIONS: Polymer-free coating with ciglitazone, a PPARg agonist is feasible and stable over time. Our data prove unimpaired endothelial coverage of a ciglitazone-coated vascular stent system by histology and OCT. Thus, this PPARg agonist coating deserves further investigation to evaluate its potency on local neointimal suppression.

Optimal prosthesis sizing in transcatheter aortic valve implantation by exclusive use of three-dimensional transoesophageal echocardiography.

PURPOSE: The assessment of aortic annular size is critical, and inappropriate sizing is thought to be a main reason of paravalvular aortic regurgitation. Multidetector computed tomograph is associated with the risk of contrast nephropathy. For optimal evaluation of the complex structure of the aortic annulus, three-dimensional (3D)-methods should be used. We therefore sought to determine the value of 3D-transoesophageal echocardiography (3D-TEE) for appropriate sizing. METHODS: Hundred and one patients (mean age 81·4 years) with symptomatic aortic valve stenosis (AS) and high surgical risk profile (mean log. EuroScore 28·8%) being scheduled for transcatheter aortic valve implantation (TAVI) were included. 2D- and 3D-TEE were performed before the procedure to evaluate the aortic annulus diameter. RESULTS: Maximum, minimum and mean (max diameter + min diameter/2) annulus diameters were 24·7, 23·1 and 23. 9 mm in 3D-TEE and compared to 22·6 mm in 2D-TEE (P<0·001; 0·07; <0·001). The interobserver variability for 3D-TEE was low with a mean difference of 0·18 mm compared to 2D-TEE with 0·59 mm. The application of 3D-TEE caused a change of prosthesis size selection in 40% of patients compared to 2D-TEE. In this study, we implanted three different types of catheter-mounted valves (Edwards-SAPIEN(™) XT valve, CoreValve(™) and JenaValve(™) ). Final angiography confirmed valve competence (mild insufficiency) in 91%, and there was no aortic regurgitation greater than moderate in the follow-up echocardiographic evaluation. CONCLUSION: Assessment of aortic annulus dimensions for TAVI size selection can safely be performed with 3D-TEE only. Based on our results with significantly higher annulus diameter compared to 2D-TEE, we recommend 3D-TEE to reduce prosthesis undersizing.

Interventional left atrial appendage occlusion: added value of 3D transesophageal echocardiography for device sizing.

Aim of this study was the assessment of left atrial appendage (LAA) dimensions comparing 2D- to 3D-TEE measurements in patients with nonvalvular atrial fibrillation undergoing percutaneous LAA occlusion. Patients underwent transesophageal echocardiography (TEE) before, during and 45 days after intervention. The maximal LAA orifice diameters in 2D-TEE (LODmax 2D) were obtained from multiple views. Test-retest reliability (screening vs. implantation), inter- and intra-observer variability for echocardiographic parameters were assessed by two independent examiners. Overall, 74 patients underwent percutaneous LAA occlusion. 2D-TEE significantly underestimated the maximal LAA orifice diameter compared with 3D-TEE (screening LODmax 2D 21.11 ± 2.75 mm vs. 22.52 ± 3.45 mm for LODmax 3D, p < 0.001; during implantation LODmax 2D 21.56 ± 3.48 mm vs. 22.99 ± 3.24 mm for LODmax 3D, p < 0.001). The intraobserver and interobserver variability calculated as coefficient of variation (CV) were both lower for the 3D-TEE quantification of the maximal orifice diameter (intraobserver CV for 3D-TEE 6.07 % vs. 9.31 % for 2D-TEE; interobserver CV for 3D-TEE 6.73 % vs. 9.69 % for 2D-TEE). Compared to 3D-TEE the test-retest reliability of 2D-TEE showed a lower intraclass correlation coefficient calculated as average of raters (0.92 for 3D-TEE vs. for 2D-TEE 0.78). Firstly, 2D-TEE significantly underestimates the maximal LAA orifice diameter compared to 3D-TEE. Secondly, 3D-TEE measurements are associated with a lower observer variability and higher reliability than 2D-TEE.

Time course of vascular response after an a priori strategy of bare metal stent implantation post-dilated with a paclitaxel-coated balloon: Implementation of a three-dimensional analysis algorithm with optical coherence tomography.

BACKGROUND: An a priori combined therapy of a bare metal stent post-dilated with a paclitaxel- -coated balloon (PCB) was investigated with optical coherence tomography (OCT) at 2 and 6 months regarding vessel response. Previous studies have shown inconsistent results and the time course of vessel healing after such an interventional strategy is unknown. METHODS: Thirty-three de novo lesions in 32 patients were electively treated. Six-month OCT analysis was available in 24 lesions. Two-month OCT follow-up was obtained in 16 lesions. Sequential OCT at 2 and 6 months was available in 7 patients. A novel 3-dimensional picture of vessel segments as spread outs was implemented. RESULTS: Severe incomplete stent apposition (ISA) accompanied by significantly lower strut coverage were found at 2-month compared with 6-month follow-up (ISA struts: 11.4 ± 11.8% vs. 1.8 ± 4.8%, p = 0.001; uncovered struts: 14.5 ± 14.8% vs. 2.0 ± 5.3%, p = 0.001). ISA size diminished over time and the possibly observed phenomenon of positive vessel remodeling (remodeling volume: 4.9 ± 5.9 mm3 at 2-months vs. 2.0 ± 2.6 mm3 at 6-months; p = 0.042) was largely reversible in most lesions. CONCLUSIONS: Bare metal stenting with adjunctive application of paclitaxel by a coated bal-loon shows transient severe incomplete strut apposition, most likely due to focal positive ves-sel remodeling. Thus, caution is needed in bailout situations following a PCB angioplasty. A novel illustration of OCT parameters as "carpet views" enables a comprehensive analysis of investigated stents.

Physiological range of mechanical synchronicity of the human heart: comparison between different echocardiographic assessment modalities.

Tissue Doppler was performed to assess physiological ranges of mechanical synchronicity in 47 patients aged 38 to 81 y with normal coronary angiograms, ECG recordings and echocardiographic findings. Maximal time delays between two different left ventricular (LV) walls in long axis time-to-peak tissue displacement (TD_D), respectively in time-to-peak strain (TD_S), time-to-peak strain rate (TD_SR), time-to-peak systolic (TD_VS) and early diastolic (TD_VE) velocities of basal and midwall segments were determined as values corrected for heart rate in a 16-segment LV model and in the right ventricle (RV). Strain (TD_S: LV = 212 +/- 108 ms, RV = 195 +/- 15 ms) and strain rate (TD_SR: LV = 183 +/- 67 ms, RV = 120 +/- 60 ms) showed the highest dyssynchrony values (TD_D: LV = 110 +/- 96 ms, RV = 42 +/- 38 ms; TD_VS: LV = 82 +/- 47 ms, RV = 36 +/- 36 ms; TD_VE: LV = 73 +/- 36 ms, RV = 46 +/- 20 ms) in both ventricles. There was no significant association between a certain LV wall and the occurrence of the earliest, respectively latest peak values of any parameter.

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.

Natural history of small and medium-sized side branches after coronary stent implantation.

OBJECTIVE: Our purpose was to identify angiographic and procedural predictors for acute and late side branch occlusion after coronary stent implantation. METHODS: We evaluated 185 patients with 185 lesions with 255 side branches with a mean reference diameter of 1.45 +/- 0.38 mm; the lesions were covered by 240 stents. Angiographic follow-up was completed in 99 patients with 133 side branches 206 +/- 120 days after stent implantation and clinical follow-up was available in 136 patients. Side branch occlusion (SBO) was defined as a Thrombolysis In Myocardial Infarction (TIMI) flow < or =1. RESULTS: Acute SBO affected 54 side branches in 49 patients and was not associated with death or Q-wave infarction. By logistic regression, independent predictors for acute SBO were (1) the reference side branch diameter (RLD) at baseline (OR [odds ratio] 0.217, 95% CI 0.07-0.67, P =.008); (2) an ostial side branch stenosis before stenting (OR 2.96, 95% CI 1.26-6.95, P =.013); (3) the involvement of the side branch origin within the lesion of the parent vessel (OR 2.77, 95% CI 1.17-6.57, P =.021); and (4) the balloon-to-artery ratio (OR 4.66, 95% CI 1.18-18.42, P =.028). Among the initially occluded side branches, 81.8% were spontaneously reperfused at follow-up. Late SBO involved 12% of the side branches without impaired antegrade flow after stenting and was predicted by the initial RLD of the side branch (OR 0.07, 95% CI 0.01-0.8, P =.032). Chronic SBO occurred in 13.5% of cases and was also predicted by the baseline RLD (OR 0.13, 95% CI 0.02-0.8, P =.028). CONCLUSIONS: Acute SBO after stenting occurred in 21.2% of cases and had a benign course. Most acutely occluded side branches underwent late spontaneous reperfusion. A baseline side branch diameter >1.4 mm predicted a preserved antegrade flow immediately after stent implantation, as well as during follow-up.