Rapid right ventricular pacing with MR-compatible pacemaker lead for MR-guided aortic balloon valvuloplasty in swine.

PURPOSE: To assess the feasibility and effectiveness of rapid right ventricular pacing with a magnetic resonance (MR)-compatible pacemaker lead during MR-guided aortic valvuloplasty. MATERIALS AND METHODS: This study was approved by the institutional animal research committee. Seven pigs were investigated. All experiments were performed with an interventional 1.5-T MR system. Interventions were monitored with a steady-state free precession real-time imaging sequence. An MR-compatible pacemaker lead was placed in the right ventricular apex with MR guidance before valvuloplasty. After positioning the balloon in valve position, valvuloplasty was performed with rapid right ventricular rapid pacing at a heart rate of 180 beats per minute to minimize cardiac output. RESULTS: Positioning of the pacemaker lead with MR guidance was feasible in all swine (sensing, 6 mV +/- 1; threshold, 1 V +/- 0.5). The lead could be seen on steady-state free precession images without inducing any artifacts. Rapid right ventricular pacing was feasible in all swine, and balloon stability at the time of inflation was achieved with no balloon movement. Aortic valvuloplasty was successfully accomplished in all experiments. CONCLUSION: Rapid right ventricular pacing with an MR-compatible pacemaker lead is feasible and effective.

Feasibility, safety, and efficacy of real-time three-dimensional transoesophageal echocardiography for guiding device closure of interatrial communications: initial clinical experience and impact on radiation exposure.

AIMS: Our aim was to assess the feasibility and safety of real-time (RT) three-dimensional (3D) transoesophageal echocardiography (TEE) for guiding transcatheter closure of interatrial communications and to evaluate its additional benefit over conventional 2D TEE in reducing radiation exposure for the patient. METHODS AND RESULTS: Twenty-five patients undergoing device closure of their interatrial defect had the procedure guided by fluoroscopy, 2D TEE, and RT 3D TEE. We retrospectively compared this group with a historical control group in which interventional guidance was performed using fluoroscopy and 2D TEE alone. The application of RT 3D TEE allowed safe device deployment in all patients without any complications, resulting in a reduction of mean fluoroscopy time (10 +/- 6 to 6 +/- 4 min, P < 0.01), mean dose area product (DAP) (964 +/- 628 to 535 +/- 464 cGy cm(2), P < 0.01), and mean DAP per individual body surface area (494 +/- 317 to 273 +/- 221 cGy cm(2)/m(2), P < 0.01). CONCLUSION: RT 3D TEE as an adjunct to 2D TEE is a feasible and safe tool to guide transcatheter device closure of interatrial communications, resulting in a reduction of radiation exposure. These data indicate that RT 3D TEE can be used to safely monitor interatrial defect closure in clinical routine.

Association of fetuin-A levels with the progression of aortic valve calcification in non-dialyzed patients.

AIMS: Fetuin-A has been identified as a potent circulating inhibitor of ectopic calcification. We investigated the relationship between baseline fetuin-A serum levels and the rate of progression of aortic valve calcification (AVC) in non-dialyzed patients with aortic valve disease (AVD). METHODS AND RESULTS: Seventy-seven patients (mean age 70 +/- 8 years) with echocardiographically proven AVD were collected. In all patients, serum fetuin-A levels, creatinine, calcium, lipid parameters, and C-reactive protein were measured at baseline. For quantification of AVC progression, all patients underwent multislice spiral computed tomography examinations at baseline and after a mean follow-up of 12.6 +/- 1.4 months (range 7-18 months). In a multifactorial analysis of covariance including fetuin-A levels, baseline AVC score, the covariables sex, age, body mass index, C-reactive protein, glomerular filtration rate, serum lipids, diabetes, smoking status, and hypertension, only serum fetuin-A levels significantly predict the progression of AVC (P < 0.001). Post hoc analysis demonstrated that patients with baseline fetuin-A levels lower than the median of the cohort (0.72 g/L) showed a significantly higher increase of AVC scores (34.6 +/- 31.4%) than patients with fetuin-A levels larger than the median (10.0 +/- 11.2%, P < 0.001) despite comparable baseline AVC scores. In addition, fetuin-A levels were associated with major adverse clinical events (MACE; P = 0.03). CONCLUSION: Serum levels of the calcification inhibitor fetuin-A are associated with the progression of AVC and MACE, independent of the renal function and inflammation.

Impact of infarct transmurality on layer-specific impairment of myocardial function: a myocardial deformation imaging study.

AIMS: To evaluate deformation parameters of an endocardial, mid-myocardial, and epicardial myocardial layer in different transmurality of myocardial infarction and assess whether layer-specific deformation analysis allows definition of infarct transmurality. METHODS AND RESULTS: Fifty-six patients (mean age 55 +/- 9 years, 38 men) with chronic ischaemic left ventricular (LV) dysfunction underwent two-dimensional echocardiography and contrast-enhanced magnetic resonance imaging (ceMRI). The extent of myocardial infarction was determined as relative amount of hyperenhancement by ceMRI in a 16-segment LV model (0%, no infarction; 1-50%, non-transmural infarction; 51-100%, transmural infarction). On the basis of two-dimensional echocardiographic parasternal short-axis views peak systolic circumferential strain was determined for the total wall thickness and for each of three myocardial layers (endocardial, mid-myocardial, and epicardial) using an automatic frame-by-frame tracking system of acoustic echocardiographic markers (EchoPAC, GE Ultrasound). In non-transmural infarction impairment of circumferential strain was greater in the endocardial than the epicardial layer, relative reduction compared with control segments, 45% vs. 28% (P < 0.001), respectively. In transmural infarction additional impairment of circumferential strain was greater in the epicardial than the endocardial layer, relative reduction compared with non-transmural infarction 29% vs. 7% (P < 0.001), respectively. Endocardial layer circumferential strain allowed distinction of non-transmural vs. no infarction with higher accuracy than total wall thickness strain [area under the curve (AUC) 0.842 vs. 0.774, respectively, P = 0.001]. Epicardial layer circumferential strain allowed distinction of transmural from non-transmural infarction with higher accuracy than total wall thickness strain (AUC 0.819 vs. 0.762, respectively, P = 0.005). CONCLUSION: Non-transmural infarction results in greater functional impairment of the endocardial than of the epicardial myocardial layer. In transmural infarction both layers are affected similarly compared with controls. A layer-specific analysis of myocardial deformation allows accurate discrimination between different transmurality categories of myocardial infarction.

Registration of coronary venous anatomy to the site of the latest mechanical contraction.

OBJECTIVE: Cardiac resynchronization therapy (CRT) provides a therapeutic option for patients with congestive heart failure (CHF). There is evidence that the optimal pacing site (OIS) is vicinal to the region of the latest contraction (RLC). However, the RLC is not identified routinely to guide lead implantation to the coronary venous system (CVS). The aim of this study was: (i) to develop a software over-imposing CVS-anatomy on parametric images of left ventricular dyssynchrony in a 3D-format obtained from computed tomography (CT) and cardiac magnetic resonance imaging (MRI); and (ii) to apply this 3D-software for analysing the possible correlation between functional/ clinical improvement and the distance between final implantation site (FIS) and RLC. METHODS AND RESULTS: In 20 CHF-patients (11 men, 65.6 +/- 6.8 y, ejection fraction (EF): 27.5 +/- 6.1%) CRT-leads were implanted; follow-up included echocardiographic and exercise evaluation. The OIS and the FIS were noted on 3D-registrations and the distances OIS-RLC and FIS-RLC measured.The target vessel was reached in 14 cases. NYHA class and EF improved significantly with a low rate of non-responders of 3 (15%) (EF) and 4 (20%) (NYHA). Image registration was possible in all patients. Post-process 3D-analysis revealed no correlation between the distance FIS-RLC and functional or echocardiographic improvements.There was a trend towards a shorter distance FIS-RLC in patients classified as responders (EF). NYHA class improved significantly better in patients with target vessel implantation. CONCLUSIONS: Registration of CT/MRI-images enables efforts to reach the RLC by preoperative identification of corresponding veins. Larger randomized trials must define the definite therapeutic benefit.

Relation of circulating Matrix Gla-Protein and anticoagulation status in patients with aortic valve calcification.

Matrix-Gla Protein (MGP) is a vitamin K-dependent protein acting as a local inhibitor of vascular calcification. Vitamin K-antagonists (oral anticoagulant; OAC) inhibit the activation of MGP by blocking vitamin K-metabolism. The aim of this study was to investigate the effect of long-term OAC treatment on circulating MGP levels in humans and on MGP expression in mice. Additionally, we tested the association between circulating inactive MGP (ucMGP) levels and the presence and severity of AVC in patients with aortic valve disease (AVD). We analysed circulating ucMGP levels in 191 consecutive patients with echocardiographically proven calcific AVD and 35 control subjects. The extent of AVC in the patients was assessed by multislice spiral computed tomography. Circulating ucMGP levels were significantly lower in patients with AVD (348.6 +/- 123.1 nM) compared to the control group (571.6 +/- 153.9 nM, p < 0.001). Testing the effect of coumarin in mice revealed that also the mRNA expression of MGP in the aorta was downregulated. Multifactorial analysis revealed a significant effect of glomerular filtration rate and long-term OAC therapy on circulating ucMGP levels in the patient group. Subsequently, patients on long-term OAC had significantly increased AVC scores. In conclusion, patients with calcific AVD had significantly lower levels of circulating ucMGP as compared to a reference population, free of coronary and valvular calcifications. In addition, our data suggest that OAC treatment may decrease local expression of MGP, resulting in decreased circulating MGP levels and subsequently increased aortic valve calcifications as an adverse side effect.

Gd-BOPTA for assessment of myocardial viability on MRI: changes of T1 value and their impact on delayed enhancement.

Gadobenate (Gd-BOPTA), injected at a dose of 0.1 mmol/kg body weight, was compared with gadopentetate (Gd-DTPA), injected at a dose of 0.2 mmol/kg body weight, for delineation of myocardial infarction interindividually in two groups of 26 patients each. Delayed enhancement images were assessed subjectively for image quality, and measured for regional T1 values before, 3 min after and 25 min after the injection of each contrast agent. In the 26 patients who received Gd-BOPTA, T1 values of remote myocardium were 1,070 +/- 125 ms, 358 +/- 78 ms and 562 +/- 108 ms before, 3 min after and 25 min after injection, respectively. Infarcted myocardium values were 1,097 +/- 148 ms, 246 +/- 68 ms and 373 +/- 84 ms and left ventricular blood pool 1,238 +/- 95 ms, 194 +/- 47 ms and 373 +/- 72 ms. In the 26 patients who received Gd-DTPA, T1 values were 1,087 +/- 96 ms, 325 +/- 60 ms and 555 +/- 108 ms for remote myocardium; 1,134 +/- 109, 210 +/- 43 ms and 304 +/- 57 ms for infarcted myocardium; and 1,258 +/- 104 ms, 166 +/- 27 ms and 351 +/- 73 ms for left ventricular blood pool. Delayed enhancement image quality showing myocardial infarction was rated good (54%) and excellent (46%) after Gd-BOPTA, and good (58%) and excellent (42%) after Gd-DTPA (no significant differences). A single dose of Gd-BOPTA compared with a double dose of Gd-DTPA causes similar changes of T1 values in infarcted and remote myocardium and provides fairly similar contrast between infarcted and remote myocardium (0.64 +/- 14 versus 0.71 +/- 11) and slightly higher contrast between left ventricular blood and infarcted myocardium (0.22 +/- 17 versus 0.14 +/- 6; p < 0.05). Administration of 0.1 mmol/kg body weight Gd-BOPTA can provide similar late enhancement images compared with the standard 0.2 mmol/kg body weight dose of Gd-DTPA due to the higher T1 relaxivity associated with the former.

Real-time three-dimensional transoesophageal echocardiography for guidance of non-coronary interventions in the catheter laboratory.

The growing need for less invasive therapies of cardiac disease creates the necessity for improved imaging guidance. Although two-dimensional transthoracic and transoesophageal echocardiography (TEE) have been shown to be essential tools for planning and execution of cardiac interventions, the benefit of three-dimensional TEE for the guidance of interventional procedures still needs to be evaluated. This review aims to describe our first experiences with real-time (RT) three-dimensional TEE for the guidance of percutaneous non-coronary interventions in the catheter laboratory. We used a matrix array TEE probe capable of generating three-dimensional images of cardiac structures in RT. We applied this innovative technique to monitor atrial septal defects or patent foramen ovale closures, valve procedures such as mitral and aortic valve interventions, and electrophysiological procedures. Our first experience using RT three-dimensional TEE for the guidance of percutaneous cardiac interventions in the catheter laboratory demonstrates that this technique is feasible to guide interventions, providing fast and complete information about the underlying pathomorphology, improving spatial orientation, and additionally allowing the online monitoring of the procedure. These benefits may accelerate the learning curve and improve confidence of the interventional cardiologist in order to increase safety, accuracy, and efficacy of interventional cardiac procedures.

Feasibility and initial experience of assessment of mechanical dyssynchrony using cardiovascular magnetic resonance and semi-automatic border detection.

BACKGROUND: The systolic dyssynchrony index (SDI) has been introduced as a measure of mechanical dyssynchrony using three-dimensional echocardiography to select patients who may benefit from cardiac resynchronization therapy (CRT). However, three-dimensional echocardiography may be inadequate in a number of patients with suboptimal acoustic window and no single echocardiographic measure of dyssynchrony has proven to be of value in selecting patients for CRT. Thus, the aim of this study was to determine the value of cardiovascular magnetic resonance (CMR) for the assessment of the SDI in patients with reduced LV function as well as in healthy controls using semi-automatic border tracking. METHODS: We investigated a total of 45 patients including 35 patients (65 +/- 8 years) with reduced LV function (EF 30 +/- 11%) and a wide QRS complex as well as 10 control subjects (42 +/- 21 years, EF 70 +/- 11%). For cine imaging a standard SSFP imaging sequence was used with a temporal resolution of 40 frames per RR-interval. Quantitative analysis was performed off-line using a software prototype for semi-automatic border detection. Global volumes, ejection fraction and the SDI were calculated in each subject. SDI was compared with standard echocardiographic parameters of dyssynchrony. RESULTS: The mean SDI differed significantly between patients (14 +/- 5%) and controls (5 +/- 2%, p < 0.001). An exponential correlation between the EF and the SDI was observed (r = -0.84; p < 0.001). In addition, a significant association between the SDI and the standard deviation of time to peak systolic motion of 12 LV segments (Ts-SD) determined by echocardiography was observed (r = 0.66, p = 0.002). CONCLUSION: The results of this preliminary study suggest that CMR with semi-automatic border detection may be useful for the assessment of mechanical dyssynchrony in patients with reduced LV function.

Relation of optimal lead positioning as defined by three-dimensional echocardiography to long-term benefit of cardiac resynchronization.

We sought to define the impact of echocardiographically defined left ventricular (LV) lead position on the efficacy of cardiac resynchronization therapy (CRT) in a serial study using 3-dimensional echocardiography. Fifty-eight consecutive patients (53+/-9 years of age; 37 men) with heart failure were included in the study. Echocardiograms were obtained before CRT, within 7 days after implantation, and at 12+/-2 months of follow-up using a 3-dimensional digital ultrasound scanner (iE33, Philips, Andover, Massachusetts). Analysis of the temporal course of contraction in 16 LV segments was performed offline using a semiautomatic contour tracing software (LV Analysis, TomTec, Unterschleissheim, Germany). Based on the resulting volume/time curves the segment with the latest minimum of systolic volume in each patient was identified preoperatively (segment A). In addition, the temporal difference between the pre- and postoperative (within 7 days) minimum of systolic volume was determined for each segment. The segment with the longest temporal difference was defined to show the greatest effect of CRT. Location of the LV lead tip was assumed to be within this segment (segment B). LV lead position was defined as optimal when segments A and B were equal and as nonoptimal when they were far from each other. Using this definition, 26 patients had a nonoptimal and 32 patients an optimal LV lead position. Before CRT ejection fraction (32+/-4% vs 31+/-6%), LV end-systolic and end-diastolic volumes (242+/-92 vs 246+/-88 ml, 315+/-82 vs 323+/-90 ml), and peak oxygen consumption (14.3+/-1.4 vs 14.6+/-1.5 ml/min/kg) were equal in the 2 groups. At 12+/-2 months of follow-up, patients with an assumed optimal LV lead position showed greater increases of ejection fraction (10+/-2% vs 6+/-3%) and peak oxygen consumption (2.4+/-0.3 vs 1.5+/-0.4 ml/min/kg) and greater decreases of LV end-systolic (32+/-7 vs 21+/-5 ml) and end-diastolic (20+/-7 vs 13+/-6 ml) volumes. In conclusion, correspondence of the segment with the latest preoperative LV contraction with the segment with the greatest effect based on CRT results in a significantly greater benefit of ejection fraction and peak oxygen consumption and a greater improvement in LV remodeling. Thus, there is an optimal LV lead position that should be obtained.

Comparison of magnetic resonance perfusion imaging versus invasive fractional flow reserve for assessment of the hemodynamic significance of epicardial coronary artery stenosis.

This study evaluated whether first-pass perfusion cardiovascular magnetic resonance (FP-CMR) could predict the hemodynamic significance of epicardial coronary artery stenosis as defined by invasively determined fractional flow reserve at coronary angiography. In 19 patients with known coronary artery disease (CAD), the hemodynamic relevance of 22 stenoses (mean angiographic severity 73 +/- 9%) was determined using fractional flow reserve measurements (cutoff 0.75). Results were compared with a territorial index of myocardial perfusion reserve (MPR) derived from FP-CMR. In addition, 9 age-matched patients with low prevalence of risk factors and without CAD at angiography served as a control group. A cutoff of 1.5 for MPR separated hemodynamically relevant from nonrelevant stenoses with a sensitivity and specificity of 92% and 92%, respectively. The area under the receiver-operator characteristic curve was 0.97. In the patient group, territories supplied by arteries without significant stenosis (

Evaluation of aortocoronary bypass stents with cardiac MDCT compared with conventional catheter angiography.

OBJECTIVE: The objective of our study was to determine the accuracy of 16-MDCT for evaluation of stent patency and in-stent stenosis in venous coronary bypass grafts. SUBJECTS AND METHODS: Fourteen patients who had previous stent placements in stenosed venous coronary bypass grafts underwent contrast-enhanced MDCT of the heart (collimation, 16 x 0.75 mm; 120 kV; 550 mAs(eff)) and invasive coronary angiography. A total of 20 stents were evaluated: Vessel and stent diameters proximal to, distal to, and at various sites inside the stent were measured on both techniques, and Bland-Altman plots and correlations were calculated. Image noise and image quality were also assessed applying a Student's t test for data comparison of image noise. RESULTS: All 20 bypass stents were correctly classified as patent. Vessel diameters outside the stent showed an excellent correlation (r = 0.90) and in-stent diameters showed a good correlation (r = 0.72), with lower values for MDCT due to blooming artifacts. All significant in-stent stenoses were correctly classified. CONCLUSION: In patients suspected of bypass in-stent stenosis, 16-MDCT may be considered as a valuable alternative to conventional angiography for evaluating bypass patency and in-stent stenosis.

MDCT detection of mitral valve calcification: prevalence and clinical relevance compared with echocardiography.

OBJECTIVE: The purpose of this study was to analyze the prevalence and clinical significance of mitral valve calcification incidentally detected on chest CT scans in comparison with echocardiography. MATERIALS AND METHODS: The data of 390 patients (227 men and 163 women; mean age, 62.4 +/- 12.2 years) who underwent MDCT of the chest and echocardiography were retrospectively evaluated. On MDCT, mitral valve leaflet and annulus calcification were visually graded on a scale of 0-3, with grade 0 denoting no calcification and grade 3 indicating severe calcification. CT findings were correlated with hemodynamic data obtained at echocardiography. Unpaired Student's t tests, chi-square analysis, and a weighted-kappa test were used to compare results. RESULTS: In 32 (8.2%) of 390 patients, chest MDCT revealed mitral valve leaflet calcification. Fifteen of these patients (15/390, 3.8%) presented with mitral valve stenosis. Excellent agreement (kappa = 0.882) was seen between the presence of mitral valve calcification on MDCT and echocardiographically proven mitral valve sclerosis. Mitral valve leaflet calcification on MDCT and the severity of mitral valve disease on echocardiography showed a substantial agreement (kappa = 0.730). A significant relationship was seen between the degree of mitral valve calcification on MDCT and the echocardiographically determined severity of mitral valve disease (no sclerosis vs mitral sclerosis vs mitral stenosis; p < 0.0001). CONCLUSION: Mitral valve leaflet calcification on MDCT indicates mitral valve sclerosis or stenosis. Thus, patients presenting with incidentally detected mitral valve leaflet calcification on chest CT may benefit from a functional assessment with echocardiography.

Assessment of myocardial viability in reperfused acute myocardial infarction using 16-slice computed tomography in comparison to magnetic resonance imaging.

OBJECTIVES: The aim of this study was to examine if contrast-enhanced multislice spiral computed tomography (MSCT) is comparable to contrast-enhanced magnetic resonance imaging (MRI) for depiction of acute myocardial infarction (MI). BACKGROUND: Delayed-enhancement MRI of MI is well established, but there are no clinical reports about MSCT for this indication. Early perfusion deficit on MSCT has been reported to correlate with the presence of MI. METHODS: A total of 28 consecutive patients (23 men; 55.9 +/- 11.4 years) with reperfused MI underwent contrast-enhanced cardiac 16-slice MSCT. Images were acquired in the arterial phase and the late phase 15 min after administration of 120 ml contrast material. Within 5 days, patients underwent MRI after administration of 0.2 mmol Gd-dimeglumine/kg/bodyweight. All examinations were completed within two weeks after MI. The area of MI was compared between the different imaging techniques using Bland-Altman method and multivariate analysis. Agreement of the contrast enhancement patterns was evaluated with a weighted kappa test. RESULTS: Mean infarct size on MRI was 31.2 +/- 22.5% per slice compared with 33.3 +/- 23.8% per slice for late-enhancement MSCT and 24.5 +/- 18.3% per slice for early-perfusion-deficit MSCT. Bland-Altman data showed a good agreement between late-enhancement MRI and late-enhancement MSCT. Contrast enhancement patterns demonstrated an excellent agreement between late-enhancement MRI and late-enhancement MSCT (kappa = 0.878). The results were worse comparing MRI and early-phase MSCT (kappa = 0.635). CONCLUSIONS: Multislice spiral computed tomography allows for the assessment of acute MI. Late-enhancement MSCT appears to be as reliable as delayed contrast-enhanced MRI in assessing infarct size and myocardial viability in acute MI.

The role of antiplatelet agents in the management of patients receiving intracardiac closure devices.

Transcatheter closure of septal defects has become a widely used alternative to surgery or life-long anticoagulant therapy especially in patients with atrial septal defects (ASD) and patent foramen ovale (PFO). Post-procedural complications include thrombus formation on the occluder in about 0-10% of all cases. Therefore antithrombotic prophylaxis after device implantation is believed to be necessary, but still is variable and remains controversial. To date no randomized studies have been published to assess the optimal anticoagulation strategy. Thus, therapy is based on empirical data, local experience and case reports from the literature. The present review tries to give an overview on most of these mainly retrospective single center studies and summarizes their results. Factors influencing the rate of thrombus formation may be device type, existence of thrombophilic disorders and prophylactic medication. Thrombus formation has been described for each of the existing occluder types without a significant difference between the devices. For antithrombotic prophylaxis, most centers at present use either acetyl salicylic acid alone (ASA; 81 to 325 mg) for 6 months or a combination of ASA and clopidogrel (75 mg) for 6 to 8 weeks followed by ASA for additional 4 to 8 months. Inherited thrombophilic disorders should be excluded before device implantation in order to adapt antithrombotic prophylaxis. Follow-up examinations after device implantation should be performed using TEE within the first 4 weeks after implantation. Thus, thrombi may be recognized early enough to extend the antithrombotic regimen in order to avoid surgical device explantation.

Polymer-based paclitaxel-eluting stents are superior to nonpolymer-based paclitaxel-eluting stents in the treatment of de novo coronary lesions.

Although polymer coating of coronary stents enables sufficient loading and release of incorporated drugs, it has also been associated with potentially negative effects. This study compared the clinical, angiographic, and intravascular ultrasound (IVUS) outcomes of patients treated with polymer- versus nonpolymer-based paclitaxel-eluting stents (PESs). Sixty-five consecutive patients (70 de novo lesions) treated with polymer-based PESs (TAXUS, 1 microg/mm2 of paclitaxel; Boston Scientific Corp.) and 65 consecutive patients (65 de novo lesions) treated with nonpolymer-based PESs (V-Flex Plus, 2.7 microg/mm2 of paclitaxel; Cook, Inc.) were enrolled in the study. Six-month angiographic follow-up was performed on 54 lesions of the polymer-based PES group and 51 lesions of the nonpolymer-based PES group. IVUS at angiographic follow-up was performed in 61 of the first 70 included lesions. At 6-month IVUS follow-up, mean intimal hyperplasia cross-sectional area was 2.36 +/- 1.60 mm2 in the nonpolymer-based PES group versus 0.62 +/- 0.41 mm2 in the polymer-based PES group (p = 0.003). Implantation of polymer-based PESs resulted in significantly lower in-stent late lumen loss (0.22 +/- 0.27 vs 0.74 +/- 0.61 mm, respectively, p <0.001). In-stent binary restenosis rate was 5% versus 20%, respectively (p <0.001). Target lesion revascularization rate was 9% after implantation of polymer-based PES versus 18% (p = 0.128) after implantation of nonpolymer-based PES, and the major adverse cardiac event rate was 9% versus 23%, respectively (p = 0.032). In conclusion, polymer-based PESs result in superior angiographic and IVUS follow-up findings compared with nonpolymer-based PESs.

Relation of end-diastolic wall thickness and the residual rim of viable myocardium by magnetic resonance imaging to myocardial viability assessed by fluorine-18 deoxyglucose positron emission tomography.

End-diastolic wall thickness (EDWT) and thickness of the residual non-contrast-enhanced myocardial rim have been suggested as markers for the assessment of myocardial viability by cardiovascular magnetic resonance (CMR) imaging. This study compared these parameters as derived from contrast-enhanced CMR images for the prediction of myocardial viability as determined by fluorine-18 deoxyglucose positron emission tomography (FDG-PET). Twenty-two patients with ischemic cardiomyopathy (ejection fraction 31 +/- 11%) were investigated. For contrast-enhanced CMR imaging, a standard inversion-recovery sequence was used. FDG-PET was performed using a hyperinsulinemic-euglycemic clamp. Data were analyzed with a 17-segment model. Of 146 severely dysfunctional segments, 112 were assessed as viable and 34 as nonviable by nuclear imaging. Using receiver-operator characteristic analysis, areas under the curve were 0.95 for unenhanced myocardial rim (95% confidence interval 0.92 to 0.98) and 0.86 for EDWT (95% confidence interval 0.80 to 0.93, p <0.001 vs unenhanced myocardial rim) for the prediction of viability as assessed by FDG-PET. Cutoffs of 5.4 mm for EDWT and 3.0 mm for unenhanced myocardial rim were found to optimally differentiate viability by FDG-PET. In 25 segments with divergent results, 94% of segments with an EDWT < or =5.4 mm and an unenhanced myocardial rim >3.0 mm were scored as viable by FDG-PET, whereas 57% of segments with an EDWT >5.4 mm and an unenhanced myocardial rim < or =3.0 mm were scored nonviable with the reference technique. In conclusion, unenhanced myocardial rim is superior to EDWT for the prediction of myocardial viability as determined by FDG-PET and may be clinically useful for assessment of myocardial viability in patients with ischemic cardiomyopathy and regional wall thinning.

Quantification of aortic valve calcification using multislice spiral computed tomography: comparison with atomic absorption spectroscopy.

OBJECTIVES: Multislice spiral computed tomography (MSCT) allows the in vivo detection of valvular calcification. The aim of this study was to validate the quantification of aortic valve calcification (AVC) by MSCT with in vitro measurements by atomic absorption spectroscopy. METHODS: In 18 patients with severe aortic stenosis, 16 detector row MSCT (SOMATOM Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420 milliseconds tube rotation time, 12 x 0.75 mm collimation, tube voltage 120 KV) was performed before aortic valve replacement. Images were reconstructed at 60% of the RR interval with an effective slice thickness of 3 mm and a reconstruction increment of 2 mm. AVC was assessed using Agatston AVC score, mass AVC score, and volumetric AVC score. After valve replacement, the calcium content of the excised human stenotic aortic valves was determined in vitro using atomic absorption spectroscopy. RESULTS: The mean Agatston AVC score was 3,842 +/- 1,790, the mean volumetric AVC score was 3,061 +/- 1,406, and mass AVC score was 888 +/- 492 as quantified by MSCT. Atomic absorption spectroscopy showed a mean true calcification mass (Ca5(PO4)3OH) of 19 +/- 8 mass%. There was a significant correlation between in vivo AVC scores determined by MSCT and in vitro mean true calcification mass (r = 0.74, P = 0.0004 for mass AVC score, r = 0.79, P = 0.0001 for volumetric AVC score and r = 0.80, P = 0.0001 for Agatston AVC score) determined by atomic absorption spectroscopy. Linear regression analysis showed a significant association between the degree of hydroxyapatite (given in mass%) in the aortic valve and the degree of AVC (R = 0.74, F = 19.6, P = 0.0004 for mass AVC score, R = 0.80, F = 29.3, P = 0.0001 for Agatston AVC score and R = 0.79, F = 27.3, P = 0.0001 for volumetric AVC score) assessed by MSCT. CONCLUSION: MSCT allows accurate in vivo quantification of aortic valve calcifications.

Three-dimensional X-ray coronary angiography in the porcine model: A feasibility study.

RATIONALE AND OBJECTIVES: Three-dimensional high-spatial-resolution angiograms of the coronary arteries were acquired with an electrocardiogram-gated three-dimensional rotational angiography technique on an interventional X-ray system. MATERIALS AND METHODS: During selective injection of contrast material in the left and right coronary artery, projection images were obtained in eight pigs during a continuous rotation of the X-ray gantry over an angular range of 180 degrees within 8 seconds. RESULTS: Three-dimensional tomographic reconstruction depicted the proximal, medial, and distal sections of the main arteries as well as the main bifurcations in multiple cardiac phases in all animals. CONCLUSIONS: For the first time, this feasibility study shows that a three-dimensional angiogram of the coronary arteries can be obtained intraprocedurally in a conventional interventional suite by means of tomographic reconstruction from projection images.

Strain rate measurement by doppler echocardiography allows improved assessment of myocardial viability inpatients with depressed left ventricular function.

OBJECTIVES: This study sought to evaluate whether objective assessment of the myocardial functional reserve, using strain rate imaging (SRI), allows accurate detection of viable myocardium. BACKGROUND: Strain rate imaging is a new echocardiographic modality that allows quantitative assessment of segmental myocardial contractility. METHODS: In 37 patients (age 58 +/- 9 years) with ischemic left ventricular dysfunction, myocardial viability was assessed using low-dose (10 microg/kg body weight per min) two-dimensional dobutamine stress echocardiography (DSE), tissue Doppler imaging, SRI and (18)F-fluorodeoxyglucose ((18)FDG) positron emission tomography (PET). The peak systolic tissue Doppler velocity and peak systolic myocardial strain rate were determined at baseline and during low-dose dobutamine stress from the apical views. RESULTS: A total of 192 segments with dyssynergy at rest were classified by (18)FDG PET as viable in 94 and nonviable in 98. An increase of peak systolic strain rate from rest to dobutamine stimulation by more than -0.23 1/s allowed accurate discrimination of viable from nonviable myocardium, as determined by (18)FDG PET with a sensitivity of 83% and a specificity of 84%. Receiver operating characteristic (ROC) curve analysis showed an area under the curve for prediction of nonviable myocardium, as determined by (18)FDG PET using SRI, of 0.89 (95% confidence interval [CI] 0.88 to 0.90), whereas the area under the ROC curve using tissue Doppler imaging was 0.63 (95% CI 0.61 to 0.65). CONCLUSIONS: The increase in the peak systolic strain rate during low-dose dobutamine stimulation allows accurate discrimination between different myocardial viability states. Strain rate imaging is superior to two-dimensional DSE and tissue Doppler imaging for the assessment of myocardial viability.