Standardised computed tomographic assessment of left atrial morphology and tissue thickness in humans.

AIMS: Left atrial (LA) remodelling is a common feature of many cardiovascular pathologies and is a sensitive marker of adverse cardiovascular outcomes. The aim of this study was to establish normal ranges for LA parameters derived from coronary computed tomographic angiography (CCTA) imaging using a standardised image processing pipeline to establish normal ranges in a previously described cohort. METHODS: CCTA imaging from 193 subjects recruited to the Budapest GLOBAL twin study was analysed. Indexed LA cavity volume (LACVi), LA surface area (LASAi), wall thickness and LA tissue volume (LATVi) were calculated. Wall thickness maps were combined into an atlas. Indexed LA parameters were compared with clinical variables to identify early markers of pathological remodelling. RESULTS: LACVi is similar between sexes (31 ml/m2 v 30 ml/m2) and increased in hypertension (33 ml/m2 v 29 ml/m2, p = 0.009). LASAi is greater in females than males (47.8 ml/m2 v 45.8 ml/m2 male, p = 0.031). Median LAWT was 1.45 mm. LAWT was lowest at the inferior portion of the posterior LA wall (1.14 mm) and greatest in the septum (median = 2.0 mm) (p < 0.001). Conditions known to predispose to the development of AF were not associated with differences in tissue thickness. CONCLUSIONS: The reported LACVi, LASAi, LATVi and tissue thickness derived from CCTA may serve as reference values for this age group and clinical characteristics for future studies. Increased LASAi in females in the absence of differences in LACVi or LATVi may indicate differential LA shape changes between the sexes. AF predisposing conditions, other than sex, were not associated with detectable changes in LAWT.Clinical trial registration:http://www.ClinicalTrials.gov/NCT01738828.

Safety and performance of a novel embolic deflection device in patients undergoing transcatheter aortic valve replacement: results from the DEFLECT I study.

AIMS: This study aimed to evaluate the safety and performance of the TriGuard™ Embolic Deflection Device (EDD), a nitinol mesh filter positioned in the aortic arch across all three major cerebral artery take-offs to deflect emboli away from the cerebral circulation, in patients undergoing transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS: The prospective, multicentre DEFLECT I study (NCT01448421) enrolled 37 consecutive subjects undergoing TAVR with the TriGuard EDD. Subjects underwent clinical and cognitive follow-up to 30 days; cerebral diffusion-weighted magnetic resonance imaging (DW-MRI) was performed pre-procedure and at 4±2 days post procedure. The device performed as intended with successful cerebral coverage in 80% (28/35) of cases. The primary safety endpoint (in-hospital EDD device- or EDD procedure-related cardiovascular mortality, major stroke disability, life-threatening bleeding, distal embolisation, major vascular complications, or need for acute cardiac surgery) occurred in 8.1% of subjects (VARC-defined two life-threatening bleeds and one vascular complication). The presence of new cerebral ischaemic lesions on post-procedure DW-MRI (n=28) was similar to historical controls (82% vs. 76%, p=NS). However, an exploratory analysis found that per-patient total lesion volume was 34% lower than reported historical data (0.2 vs. 0.3 cm3), and 89% lower in patients with complete (n=17) versus incomplete (n=10) cerebral vessel coverage (0.05 vs. 0.45 cm3, p=0.016). CONCLUSIONS: Use of the first-generation TriGuard EDD during TAVR is safe, and device performance was successful in 80% of cases during the highest embolic-risk portions of the TAVR procedure. The potential of the TriGuard EDD to reduce total cerebral ischaemic burden merits further randomised investigation.

Assessment of isotropic calcium using 0.5-mm reconstructions from 320-row CT data sets identifies more patients with non-zero Agatston score and more subclinical atherosclerosis than standard 3.0-mm coronary artery calcium scan and CT angiography.

BACKGROUND: The presence of calcified plaque in coronary arteries can be quantified by using 0.5-mm isotropic reconstructions from 320-row CT without increased radiation dose. Little is known about reclassification of patients with non-zero Agatston scores and quantitative measures of calcified plaque using 0.5-mm reconstructions. OBJECTIVE: The aim was to compare proportions of zero vs. non-zero Agatston scores (subclinical atherosclerosis) in 0.5-mm isotropic reconstructions vs. standard 3.0-mm and CT angiography (CTA) scans on 320-row CT. METHODS: Prospectively, we quantified calcified plaque in coronary arteries in 104 patients by using non-contrast-enhanced scans with 0.5 and 3.0 mm. Coronary calcium assessment was determined by 2 observers. Clinically indicated CTA was also performed; coronary calcium assessment findings were compared with CTA. Ranked Wilcoxon test and χ2 test were performed for comparison. Reproducibility for proportion of zero vs non-zero was assessed by κ statistics. RESULTS: Median Agatston score (41.9 [interquartile range (IQR), 3.7-213.6] vs. 5.2 [IQR, 0.0-128.5]), calcium volume (53.6 mm3 [IQR, 8.1-202.3] vs. 5.1 mm(3) [IQR, 0.0-96.8],), and lesion number (10.0 [IQR, 3.5-18.5] vs. 1.0 [IQR, 0.0-6.0]) were significantly higher on 0.5-mm reconstruction (P < .0001) than on 3.0-mm reconstruction. More patients with subclinical atherosclerosis were detected on 0.5 mm than on 3.0 mm and CTA scans (76.9% vs. 53.8% vs. 54.8%; P < .0001). The κ values for inter-rater agreement were 0.94 and 0.52 on 3.0- and 0.5-mm data sets, respectively. However, when Agatston scores < 10 were excluded from analysis, the κ value rose to 0.83. CONCLUSION: Isotropic 0.5-mm reconstruction detected 23.1% and 22.1% more patients with subclinical atherosclerosis than standard 3.0-mm scans and CTA, which may be more sensitive for the detection of subclinical atherosclerosis; its potential clinical utility needs to be validated in large, prospective studies.

A peripheral blood gene expression score is associated with atherosclerotic Plaque Burden and Stenosis by cardiovascular CT-angiography: results from the PREDICT and COMPASS studies.

OBJECTIVE: We previously validated a gene expression score (GES) based on age, sex and peripheral blood cell expression levels of 23 genes measured by quantitative real-time PCR (qRT-PCR) for diagnosis of obstructive coronary artery disease (CAD) (≥ 50% luminal diameter stenosis). In this study we sought to determine the association between the GES and coronary arterial Plaque Burden and Stenosis by CT-angiography. METHODS: A total of 610 patients (mean age: 57 ± 11; 50% male) from the PREDICT and COMPASS studies from 59 centers were analyzed. Coronary artery calcium (CAC) scoring, CT angiography (CTA)-based plaque and stenosis and GES measurements were performed. CAC was expressed as Agatston score and CTA evaluated for stenosis severity: 0. None; 1. Minimal, 2. Mild, 3. Moderate, 4. Severe and 5. Occluded. Correlation analysis, one-way analysis of variance (ANOVA) and receiver operating characteristics (ROC) analyses were performed. RESULTS: GES was significantly associated with plaque burden by CAC (r = 0.50; p < 0.001) and CTA (segment involvement score index: r = 0.37, p < 0.001); a low score (≤ 15) had sensitivity of 0.71 and a high score (≥ 28) a specificity of 0.97 for the prediction of zero vs. non-zero CAC. Increasing GES was associated with a greater degree of categorical stenosis by ANOVA (p < 0.001); GES significantly correlated with maximum luminal stenosis (r = 0.41; p < 0.01) and segment stenosis score index (r = 0.38; p < 0.01). A low score had sensitivity of 0.90 and a high score a specificity of 0.87 for ≥ 70% stenosis. CONCLUSIONS: A previously validated GES is significantly associated with Plaque Burden and Stenosis by CT. CLINICAL TRIAL REGISTRATION: (PREDICT [NCT00500617] and COMPASS [NCT01117506]), www.clinicaltrials.gov.

The M235T single nucleotide polymorphism in the angiotensinogen gene is associated with coronary artery calcium in patients with a family history of coronary artery disease.

Little is known about the contribution of genetics and lipoprotein subclasses to the development of coronary artery calcification (CAC) in asymptomatic, first-degree relatives of patients with CAD. We evaluated 100 asymptomatic, non-smoking, lipid-lowering therapy-naïve, first-degree relatives of patients with obstructive CAD through testing for 27 biomarkers, 15 single nucleotide polymorphisms in 12 candidate genes, and CAC and compared them to matched controls without family history. We compared prevalence of CAC in those with and without family history and biomarkers between those with and without CAC. Mean age was 41.6 ± 9 years; 58% were female. Significantly more subjects with family history had non-zero CAC (median Agatston: 13, range 1-1107) compared to those without family history (median Agatston: 43; range 1-345) (21% vs. 9%; p = 0.028). Among subjects with family history, in subjects with positive vs. negative CAC, multivariable analysis showed significantly lower HDL-2A (999 ± 333 vs. 1262 ± 397 nmol/L) and higher frequency of a substitution of threonine for methionine at codon 235 in the angiotensinogen gene (AGT M235T) (75% vs. 54%; p < 0.05; odds ratio of 2.6 for CAC). Population attributable risk of one copy of the risk allele at the AGT locus was 16%, highest of any variable tested. In conclusion, in this population of healthy, low-risk subjects with a family history of CAD, the AGT M235T variant was the most significant predictor of CAC independent of blood pressure, raising the possibility of an alternative biological pathway.

Whole blood gene expression testing for coronary artery disease in nondiabetic patients: major adverse cardiovascular events and interventions in the PREDICT trial.

The majority of first-time angiography patients are without obstructive coronary artery disease (CAD). A blood gene expression score (GES) for obstructive CAD likelihood was validated in the PREDICT study, but its relation to major adverse cardiovascular events (MACE) and revascularization was not assessed. Patients (N = 1,160) were followed up for MACE and revascularization 1 year post-index angiography and GES, with 1,116 completing follow-up. The 30-day event rate was 23% and a further 2.2% at 12 months. The GES was associated with MACE/revascularizations (p < 0.001) and added to clinical risk scores. Patients with GES >15 trended towards increased >30 days MACE/revascularization likelihood (odds ratio = 2.59, 95% confidence interval = 0.89-9.14, p = 0.082). MACE incidence overall was 1.5% (17 of 1,116) and 3 of 17 patients had GES ≤ 15. For the total low GES group (N = 396), negative predictive value was 90% for MACE/revascularization and >99% for MACE alone, identifying a group of patients without obstructive CAD and highly unlikely to suffer MACE within 12 months.

Optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter.

3D Computed Tomography (CT) provides noninvasive, low-radiation method of coronary artery calcium (CAC) measurement. Conventional CAC images are acquired on multidetector-row CT scanners without contrast, and reconstructed with 3 mm slice thickness. The calcium volume is quantified by registering voxels with attenuation values greater than or equal to 130 Hounsfield Unit (HU). In isotropic CAC images with 0.5 mm slice thickness obtained from 320-detector row CT, the optimal value of attenuation cutoff threshold is unknown. In this paper we find the optimal cutoff threshold for calcium quantification in isotropic CT calcium scans by validating against registered intravascular ultrasound with radiofrequency backscatter (IVUS/VH). From the statistical analysis of calcium data obtained from the images of 9 patients we found a range of optimal thresholds and the conventional threshold of 130 HU was in the range. Further, the optimal values were different for individual patients.

Relationship between chest lateral width, tube current, image noise, and radiation exposure associated with coronary artery calcium scanning on 320-detector row CT.

BACKGROUND: The relationship between chest lateral width, tube current, image noise, and radiation exposure on 320-detector row CT has not been reported. OBJECTIVE: We investigated the relationships between chest lateral width, estimated radiation exposure (DLPe), and image noise in 300 patients undergoing clinical coronary calcium scanning. METHODS: Patients undergoing coronary calcium scanning with 320-detector row CT (prospective, volumetric mode, 120 kV of tube voltage, 100-550 mA of tube current, 0.5-mm detector width) were grouped by chest lateral width (small, medium, and large) from anteroposterior topograms and 100 consecutive patients were selected from each group (n = 300). Tube current, DLPe, and noise were compared among groups with Kruskal-Wallis or one-way ANOVA. Phantom experiments were performed to evaluate the accuracy of calcium quantification as a function of size and tube current. RESULTS: Median tube current in small, medium, and large patients was 130, 200, and 250 mA, respectively (P < 0.0001). Despite the use of higher tube current settings, noise levels also increased with size (20.2 ± 4.5 HU, 22.0 ± 3.9 HU, and 25.1 ± 4.9 HU, respectively; global P < 0.001). DLPe was significantly higher with increasing size (54, 83, and 104 mGy · cm, respectively; P < 0.0001). Phantom experiments showed that 50-100 mA, 150-200 mA, and approximately 300 mA in small, medium, and large phantoms were associated with stable estimate of calcium. CONCLUSIONS: Increasing chest lateral width is associated with increasing radiation exposure and image noise. The use of 50-100 mA in small and 150-200 mA in medium patients is associated with acceptable noise and stable estimate of coronary artery calcium. In large patients, precise identification of individual calcified lesions remains difficult despite increasing tube current and radiation exposure.

Coronary atherosclerosis imaging by coronary CT angiography: current status, correlation with intravascular interrogation and meta-analysis.

Coronary computed tomography angiography (CTA) allows coronary artery visualization and the detection of coronary stenoses. In addition; it has been suggested as a novel, noninvasive modality for coronary atherosclerotic plaque detection, characterization, and quantification. Emerging data show that coronary CTA-based semiquantitative plaque characterization and quantification are sufficiently reproducible for clinical purposes, and fully quantitative approaches may be appropriate for use in clinical trials. Furthermore, several lines of investigation have validated plaque imaging by coronary CTA against other imaging modalities such as intravascular ultrasound/"virtual histology" and optical coherence tomography, and there are emerging data using biochemical modalities such as near-infrared spectroscopy. Finally, clinical validation in patients with acute coronary syndrome and in the outpatient setting has shown incremental value of CTA-based plaque characterization for the prediction of major cardiovascular events. With recent developments in image acquisition and reconstruction technologies, coronary CTA can be performed with relatively low radiation exposure. With further technological innovation and clinical research, coronary CTA may become an important tool in the quest to identify vulnerable plaques and the at-risk patient.

Abnormal lipoprotein(a) levels predict coronary artery calcification in Southeast Asians but not in Caucasians: use of noninvasive imaging for evaluation of an emerging risk factor.

Subclinical atherosclerosis can be quantified by coronary artery calcium (CAC) scoring. Due to its high specificity for atherosclerosis, CAC is an excellent phenotypic tool for the evaluation of emerging risk markers. Lipoprotein(a) [Lp(a)] is atherogenic due to the presence of apoB and may be thrombogenic through its apo(a) component. Lp(a) has been linked to cardiovascular events in Caucasians; however, its link to atherosclerosis in various ethnicities remains unclear. We evaluated the ability of Lp(a) mass to predict subclinical atherosclerosis in Southeast Asians and Caucasians, as measured by CAC. Traditional lipid measurements, Lp(a) measurements, and CAC by 64-slice multidetector computed tomography was performed in 103 consecutive patients in the USA and in 104 consecutive patients in Jakarta, Indonesia. Proportion of positive CAC and median CAC in Southeast Asians and in Caucasians was 61.5% and 63.1%, and 23.5 (interquartile range, 0-270) and 13 (interquartile range, 0-388), respectively. Significantly higher proportion of Southeast Asians had elevated Lp(a) levels, compared to Caucasians (51.0% vs. 29.2%; p = 0.005). In Southeast Asians, Lp(a) remained an independent predictor of CAC with an odds ratio of 4.97 (95% confidence interval, 1.56-15.88; p < 0.0001), but not in Caucasians. Receiver operating characteristic analysis showed an improvement in area under the curve from 0.81 to 0.86 (p = 0.05) when including Lp(a) in the predictive model in Southeast Asians. This translated to 7% of Southeast Asians reclassified to correct CAC status. Lp(a) measurements may have a role in risk stratification of Southeast Asians. Ethnic variation should be taken into account when considering the use of Lp(a) measurements in risk assessment.

Guideline for minimizing radiation exposure during acquisition of coronary artery calcium scans with the use of multidetector computed tomography: a report by the Society for Atherosclerosis Imaging and Prevention Tomographic Imaging and Prevention Councils in collaboration with the Society of Cardiovascular Computed Tomography.

Coronary artery calcium (CAC) scanning is an important tool for risk stratification in intermediate-risk, asymptomatic subjects without previous coronary disease. However, the clinical benefit of improved risk prediction needs to be balanced against the risk of the use of ionizing radiation. Although there is increasing emphasis on the need to obtain CAC scans at low-radiation exposure to the patient, very few practical documents exist to aid laboratories and health care professionals on how to obtain such low-radiation scans. The Tomographic Imaging Council of the Society for Atherosclerosis Imaging and Prevention, in collaboration with the Prevention Council and the Society of Cardiovascular Computed Tomography, created a task force and writing group to generate a practical document to address parameters that can be influenced by careful attention to image acquisition. Patient selection for CAC scanning should be based on national guidelines. It is recommended that laboratories performing CAC examinations monitor radiation exposure (dose-length-product [DLP]) and effective radiation dose (E) in all patients. DLP should be <200 mGy × cm; E should average 1.0-1.5 mSv and should be <3.0 mSv. On most scanner platforms, CAC imaging should be performed in an axial mode with prospective electrocardiographic triggering, using tube voltage of 120 kVp. Tube current should be carefully selected on the basis of patient size, potentially using chest lateral width measured on the topogram. Scan length should be limited for the coverage of the heart only. When patients and imaging parameters are selected appropriately, CAC scanning can be performed with low levels of radiation exposure.

Prospective validation of standardized, 3-dimensional, quantitative coronary computed tomographic plaque measurements using radiofrequency backscatter intravascular ultrasound as reference standard in intermediate coronary arterial lesions: results from the ATLANTA (assessment of tissue characteristics, lesion morphology, and hemodynamics by angiography with fractional flow reserve, intravascular ultrasound and virtual histology, and noninvasive computed tomography in atherosclerotic plaques) I study.

OBJECTIVES: This study sought to determine the accuracy of 3-dimensional, quantitative measurements of coronary plaque by computed tomography angiography (CTA) against intravascular ultrasound with radiofrequency backscatter analysis (IVUS/VH). BACKGROUND: Quantitative, 3-dimensional coronary CTA plaque measurements have not been validated against IVUS/VH. METHODS: Sixty patients in a prospective study underwent coronary X-ray angiography, IVUS/VH, and coronary CTA. Plaque geometry and composition was quantified after spatial coregistration on segmental and slice-by-slice bases. Correlation, mean difference, and limits of agreement were determined. RESULTS: There was significant correlation for all pre-specified parameters by segmental and slice-by-slice analyses (r = 0.41 to 0.84; all p < 0.001). On a segmental basis, CTA underestimated minimal lumen diameter by 21% and overestimated diameter stenosis by 39%. Minimal lumen area was overestimated on CTA by 27% but area stenosis was only underestimated by 5%. Mean difference in noncalcified plaque volume and percent and calcified plaque volume and percent were 38%, -22%, 104%, and 64%. On a slice-by-slice basis, lumen, vessel, noncalcified-, and calcified-plaque areas were overestimated on CTA by 22%, 19%, 44%, and 88%. There was significant correlation for percentage of atheroma volume (0.52 vs. 0.54; r = 0.51; p < 0.001). Compositional analysis suggested that high-density noncalcified plaque on CTA best correlated with fibrous tissue and low-density noncalcified plaque correlated with necrotic core plus fibrofatty tissue by IVUS/VH. CONCLUSIONS: This is the first validation that standardized, 3-dimensional, quantitative measurements of coronary plaque correlate with IVUS/VH. Mean differences are small, whereas limits of agreement are wide. Low-density noncalcified plaque correlates with necrotic core plus fibrofatty tissue on IVUS/VH.

Lesion- and vessel-specific coronary artery calcium scores are superior to whole-heart Agatston and volume scores in the diagnosis of obstructive coronary artery disease.

BACKGROUND: The whole-heart coronary artery calcium (CAC) score has poor predictive value for obstructive coronary artery disease (CAD). We hypothesized that vessel- and lesion-specific CAC scores are more accurate. OBJECTIVES: To evaluate the usefulness of vessel- and lesion-specific CAC in predicting obstructive CAD and to assess the incremental value added by the vessel- and lesion-specific CAC to the conventional whole-heart CAC approach. METHODS: Ninety-one patients with CAC scores and invasive angiography (XRA) data were enrolled. Besides whole-heart CAC, Agatston score (AgSc) and volume score (VolSc) were measured individually for each lesion in the 4 major epicardial coronary arteries. Maximum and average lesion-specific scores in each vessel were also determined. For the primary analysis, obstructive CAD was defined as 50% diameter stenosis by XRA. RESULTS: Whole-heart AgSc and VolSc were not different between patients with and without obstructive CAD (P = .23 and P = .18), whereas vessel- and lesion-specific scores were (maximum lesion specific AgSc, P < .0001). Maximum lesion-specific AgSc had superior diagnostic performance compared with whole-heart AgSc (area under receiver operating characteristics, 0.71 vs 0.58). Overall sensitivity, specificity, and diagnostic accuracy were improved. When specificity was fixed at 80%, sensitivity of maximum lesion-specific AgSc was superior to whole-heart AgSc (56.6% vs 35.1%). Most importantly, with lesion-specific AgSc, fewer patients were classified as "indeterminate" compared with whole-heart AgSc (17.9% vs 50%). CONCLUSIONS: Vessel- and lesion-specific CAC scores are superior to the whole-heart AgSc and VolSc in predicting obstructive CAD. This simple refinement in CAC scoring may significantly improve the clinical predictive role of CAC imaging.

Lesion-specific coronary artery calcium quantification for predicting cardiac event with multiple instance support vector machines.

Conventional whole-heart CAC quantification has been demonstrated to be insufficient in predicting coronary events, especially in accurately predicting near-term coronary events in high-risk adults. In this paper, we propose a lesion-specific CAC quantification framework to improve CAC's near-term predictive value in intermediate to high-risk populations with a novel multiple instance support vector machines (MISVM) approach. Our method works on data sets acquired with clinical imaging protocols on conventional CT scanners without modifying the CT hardware or updating the imaging protocol. The calcific lesions are quantified by geometric information, density, and some clinical measurements. A MISVM model is built to predict cardiac events, and moreover, to give a better insight of the characterization of vulnerable or culprit lesions in CAC. Experimental results on 31 patients showed significant improvement of the predictive value with the ROC analysis, the net reclassification improvement evaluation, and the leave-one-out validation against the conventional methods.

Tissue characterization of a papillary fibroelastoma on the aortic valve by contrast-enhanced 320-detector row computed tomography.

A 56-year-old woman with a mass on the aortic valve as seen on echocardiogram underwent pre-operative contrast-enhanced cardiac computed tomography prior to removal. The mass was confirmed to be a papillary fibroelastoma histologically. Spatial co-registration between the contrast-enhanced CT cross-sectional images of the mass and the Movat's pentachrome staining revealed an association of elastic fibers with higher levels of attenuation and collagen fibers with lower levels of attenuation on CT.

Absolute coronary artery calcium scores are superior to MESA percentile rank in predicting obstructive coronary artery disease.

BACKGROUND: Coronary artery calcium scoring (CAC) is an excellent non-invasive method to evaluate coronary atherosclerotic burden. To better predict the risk of future events in an individual, their absolute CAC score is compared to an age- and gender-matched cohort in order to assign a percentile rank. However, it is unknown whether absolute CAC or percentile rank is better in predicting obstructive coronary artery disease (CAD). We hypothesized that absolute CAC is superior to percentile rank in predicting obstructive CAD. METHODS: 210 consecutive patients referred to our institution for CAC and coronary artery computed tomography angiography (CTA) were included. CAC scores were expressed as Agatston score; percentile rank as published by the Multi-Ethnic Study of Atherosclerosis. Coronary artery stenoses were graded semi-quantitatively. Receiver operating characteristics curves (ROC) were used to assess the performance of CAC to predict obstructive CAD. RESULTS: In the overall group, the area under the curve (AUC) was significantly greater for absolute CAC compared to MESA percentile rank in predicting obstructive CAD (0.80 vs. 0.72, P = 0.006). Subgroup analysis revealed similar findings: AUC for absolute CAC was greater than for MESA percentile rank in males (0.82 vs. 0.71, P = 0.008), females (0.78 vs. 0.72, P = 0.085), symptomatic patients (0.78 vs. 0.72, P = 0.067) and in asymptomatic subjects (0.89 vs. 0.74, P = 0.05). CONCLUSION: Absolute CAC is superior to MESA percentile rank in predicting obstructive CAD. This finding was seen in both symptomatic and asymptomatic patients as well as in males and females.

Dobutamine response and myocardial infarct transmurality: functional improvement after coronary artery bypass grafting--initial experience.

The Investigational Review Board approved the protocol, and all patients provided signed informed consent. The protocol was compliant with HIPAA. The purpose of the study was to prospectively test the hypothesis that addition of low-dose dobutamine and quantification of inotropic reserve in segments with 1%-50% infarct transmurality (IT) would improve the predictive value for functional recovery after revascularization in chronic infarction. Fifteen patients with multivessel coronary artery disease and left ventricular systolic dysfunction were enrolled prior to coronary artery bypass grafting (CABG). Late gadolinium-enhanced cardiac magnetic resonance (MR) imaging was used to assess IT. The percentage of wall thickening was measured with cine cardiac MR imaging at rest and during infusion of 10 (microg . kg(-1))/min dobutamine. Repeat cardiac MR imaging was performed 20 weeks +/- 4 (standard error) later. Functional parameters according to segment were compared before and after CABG by using F tests with repeated-measures models. In segments with 1%-50% IT, similar functional recovery was noted in those with 1%-25% or 26%-50% IT. However, in the same segments, those that improved with dobutamine to normal range demonstrated greater improvement in the percentage of wall thickening (22% +/- 4) after revascularization than those that did not (9% +/- 4) (P < .04). In 1%-50% IT, a normal dobutamine response helps differentiate segments with greater functional recovery after CABG.

A unique case of pulmonary artery leiomyosarcoma.

Primary pulmonary artery leiomyosarcomas are rare, and the diagnosis is usually confused with other, more common, diseases, especially pulmonary embolism. A 52-year-old male, previously healthy, sustained a cardiac arrest. Chest CT-angiography diagnosed a "saddle embolus". Local thrombolysis was tried without any obvious success. At this point, the possibility of neoplasm was entertained. A cardiac MRI showed a nonhomogeneous mass in the proximal pulmonary artery. Successful surgery was performed, and histological examination of the resected mass was consistent with leiomyosarcoma. A follow-up cardiac MRI showed no residual mass. The dilemma associated with diagnosing pulmonary artery leiomyosarcomas will be discussed.