Paradoxical low-flow aortic stenosis is defined by increased ventricular hydraulic load and reduced longitudinal strain

AIMS

Patients with paradoxical low-flow severe aortic stenosis (PLF-AS) reportedly have higher left ventricular hydraulic load and more systolic strain dysfunction than patients with normal-flow aortic stenosis. This study investigates the relationship of systolic loading and strain to PLF-AS to further define its pathophysiology.

METHODS

One hundred and twenty patients (age 79 ± 12 years, 37% men) with an indexed aortic valve area (AVAi) of 0.6 cm/m or less and an ejection fraction of 50% or higher were divided into two groups based on indexed stroke volume (SVi): PLF-AS, SVi ≤ 35 ml/m, N = 46; normal-flow aortic stenosis, SVi > 35 ml/m, N = 74). Valvular and arterial load were assessed using multiple measurements, and strain was assessed using speckle-tracking echocardiography.

RESULTS

Patients with PLF-AS were found to have more valvular load (lower AVAi, P = 0.028; lower energy loss coefficient, P = 0.001), more arterial load [decreased arterial compliance and increased systemic vascular resistance (SVR), both P < 0.001] and more total hydraulic load [increased valvuloarterial impedance (Zva), P < 0.001]. Transvalvular gradients and arterial pressures were similar. Longitudinal strain was lower in PLF-AS (P < 0.001), but circumferential and rotation strains were similar. On adjusted regression, AVAi, SVR and longitudinal strain were associated with PLF-AS [odds ratio (OR) = 1.34, P = 0.043; OR = 1.31, P = 0.004; OR = 1.34, P = 0.011, respectively]. When SVR and AVAi were replaced with Zva, longitudinal strain and Zva (OR = 1.38, P = 0.015; OR = 1.33, P < 0.001 for both, respectively) were associated with PLF-AS.

CONCLUSION

Increased hydraulic load, from more severe valvular stenosis and increased vascular resistance, and longitudinal strain impairment are associated with PLF-AS and their interplay is likely fundamental to its pathophysiology.

Electroanatomic mapping systems (CARTO/EnSite NavX) vs. conventional mapping for ablation procedures in a training program

BACKGROUND

Three-dimensional electroanatomic mapping (EAM) systems reduce radiation exposure when radio frequency catheter ablation (RFCA) procedures are performed by well-trained senior operators. Given the steep learning curve associated with complex RFCA, trainees and their mentors must rely on multiple imaging modalities to maximize safety and success, which might increase procedure and fluoroscopy times. The objective of the present study is to determine if 3-D EAM (CARTO and ESI-NavX) improves procedural outcomes (fluoroscopy time, radio frequency time, procedure duration, complication, and success rates) during CA procedures as compared to fluoroscopically guided conventional mapping alone in an academic teaching hospital.

METHODS

We analyzed a total of 1070 consecutive RFCA procedures over an 8-year period for fluoroscopic time stratified by ablation target and mapping system. Multivariate logistic regression and adjusted odds ratios were calculated for each variable.

RESULTS

No statistically significant differences in acute success rates were noted between conventional and 3-D mapping cases [CARTO (p = 0.68) or ESI-NavX (p = 0.20)]. Moreover, complication rates were also not significantly different between CARTO (p = 0.23) and ESI-NavX (p = 0.53) when compared to conventional mapping. Procedure, radio frequency, and fluoroscopy times were significantly longer with CARTO and ESI-NavX versus conventional mapping [fluoroscopy time: CARTO, 28.3 min; ESI, 28.5 min; and conventional, 24.3 min; p < 0.001)].

CONCLUSIONS

The use of 3-D EAM systems during teaching cases significantly increases radiation exposure when compared with conventional mapping. These findings suggest a need to develop alternative training strategies that enhance confidence and safety during catheter manipulation and allow for reduced fluoroscopy and procedure times during RFCA.

Increased apical rotation in severe aortic stenosis is associated with reduced survival: a speckle-tracking study

BACKGROUND

Patients with severe aortic stenosis (AS) are known to have increased left ventricular apical rotation (ApRot) during systole, but its clinical relevance is unknown. The aim of this study was to assess the association of ApRot with patient symptoms and total mortality.

METHODS

A retrospective analysis was performed on 82 patients (mean age, 77 ± 14 years; 40% men) with newly diagnosed severe AS with indexed aortic valve areas ≤ 0.6 cm(2)/m(2) and left ventricular ejection fractions ≥ 50%. Sixty-three percent of patients were symptomatic. ApRot was calculated using speckle-tracking echocardiography. Patients were divided into two groups on the basis of ApRot: high ApRot (>4.0°, n = 41) and low ApRot (≤4.0°, n = 41).

RESULTS

There were 33 deaths and 30 aortic valve replacement procedures after 33 ± 17 months of follow-up. Patients in the high-ApRot group had smaller indexed aortic valve areas (P = .021) and increased valvuloarterial impedance (P = .014). There was no difference in overall symptoms, but the low-ApRot group experienced more syncope (P = .020). Patients in the high-ApRot group had reduced survival with medical therapy (log-rank P = .018) after aortic valve replacement (log-rank P = .039) and overall (log-rank P = .009). Asymptomatic patients with low ApRot had the best survival, while asymptomatic patients with high ApRot had similar survival to that of symptomatic patients (log-rank P = .008). On adjusted Cox regression, ApRot ≥ 6.0° was independently associated with death (hazard ratio, 3.06; P = .003). On receiver operating characteristic curve analysis, ApRot added incremental prognostic value to indexed aortic valve area, symptom status, and aortic valve replacement status.

CONCLUSION

Increased ApRot is independently associated with poor survival and may represent a compensatory mechanism to preserve cardiac output against severe obstruction to flow and high systolic load.

Left ventricular early inflow-outflow index: a novel echocardiographic indicator of mitral regurgitation severity

BACKGROUND

No gold standard currently exists for quantification of mitral regurgitation (MR) severity. Classification by echocardiography is based on integrative criteria using color and spectral Doppler and anatomic measurements. We hypothesized that a simple Doppler left ventricular early inflow-outflow index (LVEIO), based on flow velocity into the left ventricle (LV) in diastole and ejected from the LV in systole, would add incrementally to current diagnostic criteria. LVEIO was calculated by dividing the mitral E-wave velocity by the LV outflow velocity time integral.

METHODS AND RESULTS

Transthoracic echocardiography reports from Montefiore Medical Center and its referring clinics from July 1, 2011, to December 31, 2011 (n=11 235) were reviewed. The MR severity reported by a cardiologist certified by the National Board of Echocardiography was used as a reference standard. Studies reporting moderate or severe MR (n=550) were reanalyzed to measure effective regurgitant orifice area by the proximal isovelocity surface area method, vena contracta width, MR jet area, and left-sided chamber volumes. LVEIO was 9.3±3.9, 7.0±3.2, and 4.2±1.7 among those with severe, moderate, and insignificant MR, respectively (ANOVA P<0.001). By receiver operating characteristic analysis, area under the curve for LVEIO was 0.92 for severe MR. Those with LVEIO ≥8 were likely to have severe MR (likelihood ratio 26.5), whereas those with LVEIO ≤4 were unlikely to have severe MR (likelihood ratio 0.11). LVEIO performed better in those with normal LV ejection fraction (≥50%) compared with those with reduced LV ejection fraction (<50%) (area under the curve 0.92 versus 0.80, P<0.001). By multivariate logistic regression analysis, LVEIO was independently associated with severe MR when compared with vena contracta width, MR jet area, and effective regurgitant orifice area measured by the proximal isovelocity surface area method.

CONCLUSION

LVEIO is a simple-to-use echocardiographic parameter that accurately identifies severe MR, particularly in patients with normal LV ejection fraction.

Prevalence, impact, and predictive value of detecting subclinical coronary and carotid atherosclerosis in asymptomatic adults: the BioImage study

BACKGROUND

Although recent studies suggest that measuring coronary artery calcification (CAC) may be superior to indirect atherosclerotic markers in predicting cardiac risk, there are limited data evaluating imaging-based biomarkers that directly quantify atherosclerosis in different vascular beds performed in a single cohort.

OBJECTIVES

The BioImage Study (A Clinical Study of Burden of Atherosclerotic Disease in an At-Risk Population) sought to identify imaging biomarkers that predict near-term (3-year) atherothrombotic events.

METHODS

The BioImage Study enrolled 5,808 asymptomatic U.S. adults (mean age: 69 years, 56.5% female) in a prospective cohort evaluating the role of vascular imaging on cardiovascular risk prediction. All patients were evaluated by CAC and novel 3-dimensional carotid ultrasound. Plaque areas from both carotid arteries were summed as the carotid plaque burden (cPB). The primary endpoint was the composite of major adverse cardiac events (MACE) (cardiovascular death, myocardial infarction, and ischemic stroke). A broader secondary MACE endpoint also included all-cause death, unstable angina, and coronary revascularization.

RESULTS

Over a median follow-up of 2.7 years, MACE occurred in 216 patients (4.2%), of which 82 (1.5%) were primary events. After adjustment for risk factors, and compared with individuals without any cPB, hazard ratios for MACE were 0.78 (95% confidence interval [CI]: 0.31 to 1.91), 1.45 (95% CI: 0.67 to 3.14), and 2.36 (95% CI: 1.13 to 4.92) with increasing cPB tertile, with similar results for CAC. Net reclassification significantly improved with either cPB (0.23) or CAC (0.25). MACE rates increased simultaneously with higher levels of both cPB and CAC.

CONCLUSIONS

Detection of subclinical carotid or coronary atherosclerosis improves risk predictions and reclassification compared with conventional risk factors, with comparable results for either modality. Cost-effective analyses are warranted to define the optimal roles of these complementary techniques. (BioImage Study: A Clinical Study of Burden of Atherosclerotic Disease in an At-Risk Population; NCT00738725).

Cyclin A2 induces cardiac regeneration after myocardial infarction through cytokinesis of adult cardiomyocytes

Cyclin A2 (Ccna2), normally silenced after birth in the mammalian heart, can induce cardiac repair in small-animal models of myocardial infarction. We report that delivery of the Ccna2 gene to infarcted porcine hearts invokes a regenerative response. We used a catheter-based approach to occlude the left anterior descending artery in swine, which resulted in substantial myocardial infarction. A week later, we performed left lateral thoracotomy and injected adenovirus carrying complementary DNA encoding CCNA2 or null adenovirus into peri-infarct myocardium. Six weeks after treatment, we assessed cardiac contractile function using multimodality imaging including magnetic resonance imaging, which demonstrated ~18% increase in ejection fraction of Ccna2-treated pigs and ~4% decrease in control pigs. Histologic studies demonstrate in vivo evidence of increased cardiomyocyte mitoses, increased cardiomyocyte number, and decreased fibrosis in the experimental pigs. Using time-lapse microscopic imaging of cultured adult porcine cardiomyocytes, we also show that Ccna2 elicits cytokinesis of adult porcine cardiomyocytes with preservation of sarcomeric structure. These data provide a compelling framework for the design and development of cardiac regenerative therapies based on cardiomyocyte cell cycle regulation.

Outcomes in patients with various forms of aortic stenosis including those with low-flow low-gradient normal and low ejection fraction

Low-flow low-gradient aortic stenosis with normal ejection fraction (LFLGNEF AS) is a newly characterized poorly understood entity within the AS spectrum. Whether LFLGNEF AS has a worse prognosis than typical AS remains controversial. We retrospectively identified 4,546 individual patients with any type of AS on echocardiogram from 2003 through 2013 and categorized them into 5 cohorts: (1) mild AS, (2) moderate AS, (3) severe AS, (4) LFLGNEF AS (ejection fraction≥55%), and (5) low-flow low-gradient low ejection fraction AS (LFLGLEF AS; ejection fraction<55%). Survival analysis was used to compare outcomes of LFLGNEF AS with those of the other cohorts. AS was classified as mild in 591 patients, moderate in 2,358, severe in 500, LFLGNEF in 776, and LFLGLEF in 318. The study group had a mean age of 80.5 years, 61% were women, and the patients were followed for 2.26±1.16 years. Among subjects managed without valve replacement, total mortality for the LFLGNEF AS group was lower compared with that in both the severe AS and the LFLGLEF AS groups (p=0.007 and p<0.001, respectively). The prognosis for LFLGNEF AS was worse, however, compared with those with mild and moderate AS (p<0.001, both). In conclusion, no survival differences were found among AS types among those who received valve replacement. The survival rate in LFLGNEF is better than that in severe AS or LFLGLEF but is worse than that in mild or moderate AS. Valve replacement seems reasonable to pursue in select patients.

Left atrial appendage closure devices

Atrial fibrillation (AF) increases the risk for thromboembolic stroke five-fold. The left atrial appendage (LAA) has been shown to be the main source of thrombus formation in the majority of strokes associated with AF. Oral anticoagulation with warfarin and novel anticoagulants remains the standard of care; however, it has several limitations, including bleeding and poor compliance. Occlusion of the LAA has been shown to be an alternative therapeutic approach to drug therapy. The purpose of this article is to review the different techniques and devices that have emerged for the purpose of occluding this structure, with a particular emphasis on the efficacy and safety studies published to date in the medical literature.

Rationale and design of a randomized trial comparing initial stress echocardiography versus coronary CT angiography in low-to-intermediate risk emergency department patients with chest pain

BACKGROUND

Comparative effectiveness research (CER) has become a major focus of cardiovascular disease investigation to optimize diagnosis and treatment paradigms and decrease healthcare expenditures. Acute chest pain is a highly prevalent reason for evaluation in the Emergency Department (ED) that results in hospital admission for many patients and excess expense. Improvement in noninvasive diagnostic algorithms can potentially reduce unnecessary admissions.

OBJECTIVE

To compare the performance of treadmill stress echocardiography (SE) and coronary computed tomography angiography (CTA) in ED chest pain patients with low-to-intermediate risk of significant coronary artery disease.

DESIGN

This is a single-center, randomized controlled trial (RCT) comparing SE and CTA head-to-head as the initial noninvasive imaging modality. The primary outcome measured is the incidence of hospitalization. The study is powered to detect a reduction in admissions from 28% to 15% with a sample size of 400. Secondary outcomes include length of stay in the ED/hospital and estimated cost of care. Safety outcomes include subsequent visits to the ED and hospitalizations, as well as major adverse cardiovascular events at 30 days and 1 year. Patients who do not meet study criteria or do not consent for randomization are offered entry into an observational registry.

CONCLUSIONS

This RCT will add to our understanding of the roles of different imaging modalities in triaging patients with suspected angina. It will increase the CER evidence base comparing SE and CTA and provide insight into potential benefits and limitations of appropriate use of treadmill SE in the ED.

Stimulating myocardial regeneration with periostin Peptide in large mammals improves function post-myocardial infarction but increases myocardial fibrosis

AIMS

Mammalian myocardium has a finite but limited capacity to regenerate. Experimentally stimulating proliferation of cardiomyocytes with extracellular regeneration factors like periostin enhances cardiac repair in rodents. The aim of this study was to develop a safe method for delivering regeneration factors to the heart and to test the functional and structural effects of periostin peptide treatment in a large animal model of myocardial infarction (MI).

METHODS AND RESULTS

We developed a controlled release system to deliver recombinant periostin peptide into the pericardial space. A single application of this method was performed two days after experimental MI in swine. Animals were randomly assigned to receive either saline or periostin peptide. Experimental groups were compared at baseline, day 2, 1 month and 3 months. Treatment with periostin peptide increased the EF from 31% to 41% and decreased by 22% the infarct size within 12 weeks. Periostin peptide-treated animals had newly formed myocardium strips within the infarct scar, leading to locally improved myocardial function. In addition the capillary density was increased in animals receiving periostin. However, periostin peptide treatment increased myocardial fibrosis in the remote region at one week and 12 weeks post-treatment.

CONCLUSION

Our study shows that myocardial regeneration through targeted peptides is possible. However, in the case of periostin the effects on cardiac fibrosis may limit its clinical application as a viable therapeutic strategy.

Individual patient data meta-analysis for the clinical assessment of coronary computed tomography angiography: protocol of the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT)

BACKGROUND

Coronary computed tomography angiography has become the foremost noninvasive imaging modality of the coronary arteries and is used as an alternative to the reference standard, conventional coronary angiography, for direct visualization and detection of coronary artery stenoses in patients with suspected coronary artery disease. Nevertheless, there is considerable debate regarding the optimal target population to maximize clinical performance and patient benefit. The most obvious indication for noninvasive coronary computed tomography angiography in patients with suspected coronary artery disease would be to reliably exclude significant stenosis and, thus, avoid unnecessary invasive conventional coronary angiography. To do this, a test should have, at clinically appropriate pretest likelihoods, minimal false-negative outcomes resulting in a high negative predictive value. However, little is known about the influence of patient characteristics on the clinical predictive values of coronary computed tomography angiography. Previous regular systematic reviews and meta-analyses had to rely on limited summary patient cohort data offered by primary studies. Performing an individual patient data meta-analysis will enable a much more detailed and powerful analysis and thus increase representativeness and generalizability of the results. The individual patient data meta-analysis is registered with the PROSPERO database (CoMe-CCT, CRD42012002780).

METHODS/DESIGN

The analysis will include individual patient data from published and unpublished prospective diagnostic accuracy studies comparing coronary computed tomography angiography with conventional coronary angiography. These studies will be identified performing a systematic search in several electronic databases. Corresponding authors will be contacted and asked to provide obligatory and additional data. Risk factors, previous test results and symptoms of individual patients will be used to estimate the pretest likelihood of coronary artery disease. A bivariate random-effects model will be used to calculate pooled mean negative and positive predictive values as well as sensitivity and specificity. The primary outcome of interest will be positive and negative predictive values of coronary computed tomography angiography for the presence of coronary artery disease as a function of pretest likelihood of coronary artery disease, analyzed by meta-regression. As a secondary endpoint, factors that may influence the diagnostic performance and clinical value of computed tomography, such as heart rate and body mass index of patients, number of detector rows, and administration of beta blockade and nitroglycerin, will be investigated by integrating them as further covariates into the bivariate random-effects model.

DISCUSSION

This collaborative individual patient data meta-analysis should provide answers to the pivotal question of which patients benefit most from noninvasive coronary computed tomography angiography and thus help to adequately select the right patients for this test.

CMR imaging assessing viability in patients with chronic ventricular dysfunction due to coronary artery disease: a meta-analysis of prospective trials

OBJECTIVES

The purpose of this study was to compare the diagnostic accuracy of cardiac magnetic resonance (CMR) assessing myocardial viability in patients with chronic left ventricular (LV) dysfunction due to coronary artery disease using 3 techniques: 1) end-diastolic wall thickness (EDWT); 2) low-dose dobutamine (LDD); and 3) contrast delayed enhancement (DE).

BACKGROUND

CMR has been proposed to assess myocardial viability over the past decade. However, the best CMR strategy to evaluate patients being contemplated for revascularization has not yet been determined. Some centers advocate DE CMR due to its high sensitivity to identify scar, whereas others favor the use of LDD CMR for its ability to identify contractile reserve.

METHODS

A systematic review of MEDLINE, Cochrane, and Embase for all the prospective trials assessing myocardial viability in subjects with chronic LV dysfunction using CMR was performed using a standard approach for meta-analysis for diagnostic tests and a bivariate analysis of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

A total of 24 studies of CMR evaluating myocardial viability with 698 patients fulfilled the inclusion criteria. Eleven studies used DE, 9 studies used LDD, and 4 studies used EDWT. Our meta-analysis indicates that among CMR methods, DE CMR provides the highest sensitivity as well as the highest NPV (95% and 90%, respectively) for predicting improved segmental LV contractile function after revascularization, followed by EDWT CMR, whereas LDD CMR demonstrated the lowest sensitivity/NPV among all modalities. On the other hand, LDD CMR offered the highest specificity and PPV (91% and 93%, respectively), followed by DE CMR, whereas EDWT showed the lowest of these parameters.

CONCLUSIONS

DE CMR provides the highest sensitivity and NPV, whereas LDD CMR provides the best specificity and PPV. In light of these findings, integrating these 2 methods should provide increased accuracy in evaluating patients with chronic LV dysfunction being considered for revascularization.

Long-term echocardiographic changes in left ventricular size and function following surgery for severe mitral regurgitation

Background

Chronic mitral regurgitation (MR) results in a state of chronic left ventricular (LV) volume overload, resulting in compensatory dilatation. Mitral valve (MV) surgery for regurgitation reduces LV preload but increases LV afterload. Few data are available documenting subsequent changes in LV size and function over time following MV surgery for severe regurgitation in unselected populations.

Material/Methods

Pre- and postoperative echocardiograms (n=454) acquired from 108 consecutive patients with chronic MR who underwent MV surgery were analyzed.

Results

LV diastolic diameter was 4 mm smaller on postoperative compared to preoperative exams, whereas LV fractional shortening (FS) was unchanged. Linear regression analysis showed no change in LV diastolic diameter over time postoperatively, whereas LV FS increased over time following surgery. Improvement in LV FS occurred at an average rate of 1.6% per year (95% CI, 0.2–2.9). Subgroups were small, but the same secular trends were generally noted in groups with or without coronary artery bypass graft surgery (CABGS) and in those with or without mitral leaflet disease.

Conclusions

Following MV surgery for MR, LV diastolic diameter reduces by 2 mm at the time of surgery, but then remains stable over time. Improvement in LV function over time postoperatively was only seen in those without concomitant CABGS, possibly related to less baseline myocardial scarring in this group.

ACCF/SCAI/STS/AATS/AHA/ASNC/HFSA/SCCT 2012 appropriate use criteria for coronary revascularization focused update: a report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, American Association for Thoracic Surgery, American Heart Association, American Society of Nuclear Cardiology, and the Society of Cardiovascular Computed Tomography

The American College of Cardiology Foundation (ACCF), Society for Cardiovascular Angiography and Interventions, Society of Thoracic Surgeons, and the American Association for Thoracic Surgery, along with key specialty and subspecialty societies, conducted an update of the appropriate use criteria (AUC) for coronary revascularization frequently considered. In the initial document, 180 clinical scenarios were developed to mimic patient presentations encountered in everyday practice and included information on symptom status, extent of medical therapy, risk level as assessed by noninvasive testing, and coronary anatomy. This update provides a reassessment of clinical scenarios the writing group felt to be affected by significant changes in the medical literature or gaps from prior criteria. The methodology used in this update is similar to the initial document, and the definition of appropriateness was unchanged. The technical panel scored the clinical scenarios on a scale of 1 to 9. Scores of 7 to 9 indicate that revascularization is considered appropriate and likely to improve patients' health outcomes or survival. Scores of 1 to 3 indicate revascularization is considered inappropriate and unlikely to improve health outcomes or survival. Scores in the mid-range (4 to 6) indicate a clinical scenario for which the likelihood that coronary revascularization will improve health outcomes or survival is uncertain. In general, as seen with the prior AUC, the use of coronary revascularization for patients with acute coronary syndromes and combinations of significant symptoms and/or ischemia is appropriate. In contrast, revascularization of asymptomatic patients or patients with low-risk findings on noninvasive testing and minimal medical therapy are viewed less favorably. The technical panel felt that based on recent studies, coronary artery bypass grafting remains an appropriate method of revascularization for patients with high burden of coronary artery disease (CAD). Additionally, percutaneous coronary intervention may have a role in revascularization of patients with high burden of CAD. The primary objective of the appropriate use criteria is to improve physician decision making and patient education regarding expected benefits from revascularization and to guide future research.

Coronary CT and the coronary calcium score, the future of ED risk stratification?

Accurate and efficient evaluation of acute chest pain remains clinically challenging because traditional diagnostic modalities have many limitations. Recent improvement in non-invasive imaging technologies could potentially improve both diagnostic efficiency and clinical outcomes of patients with acute chest pain while reducing unnecessary hospitalizations. However, there is still controversy regarding much of the evidence for these technologies. This article reviews the role of coronary artery calcium score and the coronary computed tomography in the assessment of individual coronary risk and their usefulness in the emergency department in facilitating appropriate disposition decisions. The evidence base and clinical applications for both techniques are also described, together with cost- effectiveness and radiation exposure considerations.

Abstract 272: Severity and Determinants of Underreporting of Obesity in a Diverse Population of Hospitalized Patients in an Academic Medical Center and its Impact on Mortality

Obesity has become a national epidemic with significant implications in the development of multiple diseases. Prior studies have shown that physicians often fail to diagnose obesity in the outpatient settings, and consequently fail to formulate treatment plans and medical interventions. With the introduction of electronic medical records, making the diagnosis of obesity in an inpatient setting is a straightforward process. Our objective was to determine the presence and extent of underreporting of obesity in hospitalized patients in an urban academic medical center and to identify determinants and consequences of underreporting. We used a proprietary electronic medical record aggregator platform (Clinical Looking Glass) to collect data on all adult admissions during 2007-2010 to Montefiore Medical Center, a tertiary medical center. Presence or absence of diagnosis of obesity in patients’ problem list was identified by examining inpatient problem list in the electronic record. Our study population included 22,857 obese adults (BMI of ≥ 30 kg/m 2 ) of whom 66 % were female, 37% Black, 18.45% White, and 37.9% Hispanic. Overall, only 18.4% of the study population carried the diagnosis of obesity. There was significant variation in rates of correct diagnosis among different subgroups: 20.4% in women vs. 14.4% in men; and 22.4% in Blacks vs. 13.6% in Whites. There was a linear correlation between severity of obesity and correct diagnosis (53.38% of patients with BMI >45 kg/m 2 vs. 7.89% with BMI 30-35 kg/m 2 ) (Fig. 1). In Kaplan-Meier survival analysis, patients with correctly reported obesity demonstrated decreased mortality rates after an average follow up of two years (6.4%, CI 5.6-7.3 vs. 11.4% CI 10.9-12). In conclusion, the correct diagnosis of obesity is severely underreported in hospitalized adult patients, with race, ethnicity, gender and degree of obesity being important determinants of this observation. Correct diagnosis of obesity is associated with decreased mortality over a two-year follow-up.

Automated analysis of coronary artery disease by computed tomography

Computer-assisted detection systems are widely used in many areas of radiology. Coronary computed tomography angiography is a growing area of clinical cardiology and computer-assisted detection systems play an integral part in analysis. Truly automated systems are still in clinical-trial stages, but manually assisted programs are in clinical use today for calcium scoring as well as plaque burden, composition, and stenosis analysis. They are being used as a tool for confirmation more than for diagnosis. Accurate plaque-composition analysis would be a critical tool for better understanding the mechanisms and effectiveness of novel therapies for coronary atherosclerosis. A need for a complete quick, safe, noninvasive plaque analysis is the goal of automated coronary stenosis detection systems; however, their potential clinical benefit remains unknown.

Evaluation of the detection of Mycobacterium tuberculosis with metabolic activity in culture-negative human clinical samples

Mycobacterium tuberculosis is assumed to remain in a quiescent state during latent infection, being unable to grow in culture. The aim of this study was to evaluate the detection of viable but non-cultivable bacilli with metabolic activity in human clinical samples using a procedure that is independent of the immunological status of the patient. The study was performed on 66 human clinical samples, from patients subjected to routine diagnosis to rule out a mycobacterial infection. Specimens from pulmonary and extra-pulmonary origins were verified to contain human DNA before testing for M. tuberculosis DNA, rRNA and transient RNA by real-time quantitative PCR. Clinical records of 55 patients were also reviewed. We were able to detect viable but non-cultivable bacilli with a metabolic activity in both pulmonary and extra-pulmonary samples. Mycobacterium tuberculosis RNA was detected in the majority of culture-positive samples whereas it was detected in one-third of culture-negative samples, 20% of them showed metabolic activity. Amplifications of the ftsZ gene and particularly of the main promoter of the ribosomal operon rrnA, namely PCL1, seem to be good targets to detect active bacilli putatively involved in latent infection. Moreover, this last target would provide information on the basal metabolic activity of the bacilli detected.

Can quantitative regional myocardial dynamics contribute to the differential diagnosis of acute stress cardiomyopathy?

Acute stress-induced cardiomyopathy has excessive sympathetic stimulation, microvascular dysfunction similar to hypertension. Regional prominence of left ventricular (LV) septal base and stress-induced LV hypercontractility are the particular features of both acute and chronic stress-related conditions. Novel imaging methods have shown that stress-induced cavity dilation and myocardial wall abnormalities can be a reflection of underlying previous exaggerated hypertensive episodes due to sympathetic overdrive, which results in microvascular dysfunction. Hypertension-mediated chronic stress due to increased after load episodes is possibly the main reason for blunted LV myocardial wall motion capability in patients with stress-related exaggerated hypertension. In this short report, we discussed the interrelation of myocardial dynamics and stress-induced exaggerated hypertension episodes. In addition, quantitative echocardiographic methods which previously were used for description of particular features including LV regional dynamics in hypertensive heart disease can be an option in differential diagnosis of potential cases of acute stress-induced cardiomyopathy.

Alignment of multiple complete genomes suggests that gene rearrangements may contribute towards the speciation of Mycobacteria

To more accurately define the taxonomic relationships among species belonging to the genus Mycobacterium we have applied and compared three complete genome sequence comparison procedures to existing systems. These included a nucleotide sequence comparison including both coding and no-coding regions of the genome and two genomic-order comparisons using MAUVE and M-GCAT software to provide comparative gene synteny. These methods clearly differentiated a panel of genomes from reference mycobacterial species. Overall, the speciation of bacteria through determination of gene rearrangements were consistent with the gold standard method for species definition in bacteria, DNA-DNA hybridization however within the context of this system, individual components of the Mycobacterium tuberculosis complex (MTBC) did not show sufficient diversity to classify them as a separate species. The high number of gene rearrangements observed between the species tested suggests that gene reorganization of the genome represents an important contributor to speciation within the genus Mycobacterium and other related genera. The absence of rearrangements amongst MTBC supports their consideration as a single genospecies. Some gene rearrangements provided clear internal synteny between genomes of mycobacterial strains belonging to a same species and we suggest these could be used to classify subspecies.

Left atrial size--another differentiator for cardiac amyloidosis

BACKGROUND

The "sparkled" echocardiographic appearance of amyloid has become less visually obvious in the era of harmonic imaging. Significantly dilated atria in the setting of a normal sized ventricle may be another easy visual marker for cardiac amyloidosis.

METHODS

A retrospective analysis of echocardiograms of patients with biopsy-proven cardiac amyloid compared with patients with hypertension was conducted. There were 36 patients in each group, and they were matched for left ventricular wall thickness, as well as age and sex.

RESULTS

Patients with cardiac amyloid had significantly larger atria than the group with hypertension (left atrial areas 29 cm(2) versus 19 cm(2), p<0.001, AUC 0.84, volumes 100 cm(3) versus 55 cm(3), p<0.001, AUC 0.915). A volume of 69 cm(3) produced a specificity and sensitivity of 85% for amyloidosis.

CONCLUSIONS

Atrial dilatation can be used as a visual marker for cardiac amyloidosis. This may be a simple visual method to differentiate this infiltrative cardiomyopathy from left ventricular hypertrophy.

Stress induced hypertensive response: should it be evaluated more carefully?

Various diagnostic methods have been used to evaluate hypertensive patients under physical and pharmacological stress. Several studies have shown that exercise hypertension has an independent, adverse impact on outcome; however, other prognostic studies have shown that exercise hypertension is a favorable prognostic indicator and associated with good outcome. Exercise hypertension may be encountered as a warning signal of hypertension at rest and future hypertensive left ventricular hypertrophy. The results of diagnostic stress tests support that hypertensive response to exercise is frequently associated with high rate-pressure product in hypertensives. In addition to the observations on high rate-pressure product and enhanced ventricular contractility in patients with hypertension, evaluation of myocardial contractility by Doppler tissue imaging has shown hyperdynamic myocardial function under pharmacological stress. These recent quantitative data in hypertensives suggest that hyperdynamic myocardial function and high rate-pressure product response to stress may be related to exaggerated hypertension, which may have more importance than that it has been already given in clinical practice.

ACCF/ASE/AHA/ASNC/HFSA/HRS/SCAI/SCCM/SCCT/SCMR 2011 Appropriate Use Criteria for Echocardiography. A Report of the American College of Cardiology Foundation Appropriate Use Criteria Task Force, American Society of Echocardiography, American Heart Association, American Society of Nuclear Cardiology, Heart Failure Society of America, Heart Rhythm Society, Society for Cardiovascular Angiography and Interventions, Society of Critical Care Medicine, Society of Cardiovascular Computed Tomography, Society for Cardiovascular Magnetic Resonance American College of Chest Physicians

The American College of Cardiology Foundation (ACCF), in partnership with the American Society of Echocardiography (ASE) and along with key specialty and subspecialty societies, conducted a review of common clinical scenarios where echocardiography is frequently considered. This document combines and updates the original transthoracic and transesophageal echocardiography appropriateness criteria published in 2007 (1) and the original stress echocardiography appropriateness criteria published in 2008 (2). This revision reflects new clinical data, reflects changes in test utilization patterns,and clarifies echocardiography use where omissions or lack of clarity existed in the original criteria.The indications (clinical scenarios)were derived from common applications or anticipated uses, as well as from current clinical practice guidelines and results of studies examining the implementation of the original appropriate use criteria (AUC).The 202 indications in this document were developed by a diverse writing group and scored by a separate independent technical panel on a scale of 1 to 9,to designate appropriate use(median 7 to 9), uncertain use(median 4 to 6), and inappropriate use (median 1 to 3). Ninety-seven indications were rated as appropriate, 34 were rated as uncertain, and 71 were rated as inappropriate. In general,the use of echocardiography for initial diagnosis when there is a change in clinical status or when the results of the echocardiogram are anticipated to change patient management were rated appropriate. Routine testing when there was no change in clinical status or when results of testing were unlikely to modify management were more likely to be inappropriate than appropriate/uncertain.The AUC for echocardiography have the potential to impact physician decision making,healthcare delivery, and reimbursement policy. Furthermore,recognition of uncertain clinical scenarios facilitates identification of areas that would benefit from future research.

Apical right ventricular dysfunction in patients with pulmonary hypertension demonstrated with magnetic resonance

OBJECTIVE

To evaluate segmental right ventricular (RV) dysfunction in pulmonary hypertension (PH) using cardiac magnetic resonance (CMR).

DESIGN

Cross-sectional analysis in a retrospective cohort of consecutive adult patients.

SETTING

Mount Sinai Hospital in New York.

PATIENTS

192 patients with known or suspected PH undergoing right heart catheterisation and CMR. PH was defined as mean pulmonary artery pressure ≥ 25 mm Hg. Abnormal RV ejection fraction (RVEF) was defined as <50%. Patients were classified into: group 1 (no PH, normal RVEF; n = 40), group 2 (PH, normal RVEF; n = 41) or group 3 (PH, abnormal RVEF; n=111).

INTERVENTIONS

CMR and right heart catheterisation within a 2-week interval. Main outcome measures On cine CMR images, the stack of RV short-axis views was divided into two equal halves. Basal and apical RVEF were calculated using Simpson's method, and a ratio of basal-to-apical RVEF (RVEF(ratio)) was derived.

RESULTS

Basal RVEF did not differ between groups 1 and 2 (63 ± 8% vs 64 ± 8%; p = 1); however, patients in group 2 had significantly lower apical RVEF (46 ± 13% vs 58 ± 10%; p<0.01) and higher RVEF(ratio) (median 1.4 vs 1.1; p<0.01). Both apical and basal RVEF were reduced in group 3 compared with groups 1 and 2 (p<0.01), and the RVEF(ratio) increased with increasing PH severity (p<0.01 for trend). An apical RVEF <50% was more sensitive than global RV dysfunction for the detection of PH.

CONCLUSIONS

Apical dysfunction appears to occur before global RVEF decreases in chronic PH, potentially constituting an early and sensitive marker of RV dysfunction in this setting.

New index α improves detection of pulmonary hypertension in comparison with other cardiac magnetic resonance indices

BACKGROUND

Cardiovascular magnetic resonance (CMR) has been proposed for the evaluation of patients with pulmonary hypertension (PH). However, there is no consensus on the optimal method for PH diagnosis using CMR.

OBJECTIVE

To compare the diagnostic ability of multiple CMR-derived indices for the detection of PH as determined by right heart catheterization (RHC).

METHODS

A total of 185 patients with known or suspected chronic PH who underwent cardiac CMR and RHC in ≤15 days were included. PH was defined as a mean pulmonary artery (PA) pressure ≥25 mmHg. Right ventricular (RV) volumes, RV ejection fraction (RVEF), PA areas, and PA average blood flow velocity were quantified with CMR. A novel index α was defined as the ratio between minimal PA area and RVEF.

RESULTS

According to the RHC, PH was present in 152 patients. All CMR-derived parameters correlated with the degree of mean PA pressure, with α having the highest correlation coefficient (r=0.61, p<0.001). Correlations were also highest for α in the patients with pulmonary arterial hypertension (PAH; r=0.55, p<0.001) and non-PAH subgroup (r=0.61, p<0.001). Diagnostic accuracy for the detection of PH, based on receiver operating curve analysis, was best for α (area under the curve=0.95). A cutoff value of 7.2 demonstrated a sensitivity of 90% and a specificity of 88%.

CONCLUSIONS

An easily-obtainable and novel CMR index α that combines geometrical and functional information of the PA and the RV allows for the noninvasive diagnosis of PH with high accuracy, above other common CMR-derived parameters.

Evaluation of right ventricular function and post-operative findings using cardiac computed tomography in patients with left ventricular assist devices

BACKGROUND

Right ventricular (RV) failure is a major contributor to morbidity and mortality after left ventricular assist device (LVAD) implantation. Accurate evaluation of RV function in patients with LVAD remains challenging. We hypothesized that, after LVAD implantation, electrocardiographic-gated cardiac computed tomography (CCT) allows RV evaluation with higher feasibility and reproducibility compared with echocardiography.

METHODS

Thirty-six patients with an implanted LVAD who had 2-dimensional echocardiography and CCT evaluation were studied. RV end-diastolic and end-systolic volumes and ejection fraction were quantified using CCT. RV fractional area change, tricuspid annular plane systolic excursion and RV end-diastolic short-to-long axis ratio were calculated by echocardiography. Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to assess intra- and interobserver reproducibility for all measurements.

RESULTS

The quality of CCT studies was good in all cases except for one. Intra- and interobserver reproducibility for all CCT measurements was high (interobserver ICC for RV ejection fraction = 0.89, 95% confidence interval 0.74 to 0.95). Echocardiographic indices of RV function and geometry had lower reproducibility. The echocardiographic index that best correlated with the CCT-determined RV ejection fraction was RV fractional area change (r = 0.80, p < 0.001). In addition, CCT detected relevant post-operative findings in 50% of the patients.

CONCLUSIONS

CCT is highly effective and reproducible compared with echocardiography for the evaluation of RV function in patients with LVAD support and provides relevant information on post-operative findings. Our results suggest that CCT should be considered as a useful imaging modality in this clinical setting.

Diagnostic value of coronary artery calcium scoring in low-intermediate risk patients evaluated in the emergency department for acute coronary syndrome

Early and accurate triage of patients with possible ischemic chest pain remains challenging in the emergency department because current risk stratification techniques have significant cost and limited availability. The aim of this study was to determine the diagnostic value of the coronary artery calcium score (CACS) for the detection of obstructive coronary artery disease (CAD) in low- to intermediate-risk patients evaluated in the emergency department for suspected acute coronary syndromes. A total of 225 patients presenting to the emergency department with acute chest pain and Thrombolysis In Myocardial Infarction (TIMI) scores <4 who underwent non-contrast- and contrast-enhanced coronary computed tomographic angiography were included. CACS was calculated from the noncontrast scan using the Agatston method. The prevalence of obstructive CAD (defined from the contrast scan as ≥ 50% maximal reduction in luminal diameter in any segment) was 9% and increased significantly with higher scores (p <0.01 for trend). CACS of 0 were observed in 133 patients (59%), of whom only 2 (1.5%) had obstructive CAD. The diagnostic accuracy of CACS to detect obstructive CAD was good, with an area under the receiver-operating characteristic curve of 0.88 and a negative predictive value of 99% for a CACS of 0. In a multivariate model, CACS was independently associated with obstructive CAD (odds ratio 7.01, p = 0.02) and provided additional diagnostic value over traditional CAD risk factors. In conclusion, CACS appears to be an effective initial tool for risk stratification of low- to intermediate-risk patients with possible acute coronary syndromes, on the basis of its high negative predictive value and additive diagnostic value.