Lateral annular systolic excursion ratio: A novel measurement of right ventricular systolic function by two-dimensional echocardiography.

Introduction: Accurate assessment of right ventricular (RV) systolic function has prognostic and therapeutic implications in many disease states. Echocardiography remains the most frequently deployed imaging modality for this purpose, but estimation of RV systolic function remains challenging. The purpose of this study was to evaluate the diagnostic performance of a novel measurement of RV systolic function called lateral annular systolic excursion ratio (LASER), which is the fractional shortening of the lateral tricuspid annulus to apex distance, compared to right ventricular ejection fraction (RVEF) derived by cardiac magnetic resonance imaging (CMR). Methods: A retrospective cohort of 78 consecutive patients who underwent clinically indicated CMR and transthoracic echocardiography within 30 days were identified from a database. Parameters of RV function measured included: tricuspid annular plane systolic excursion (TAPSE) by M-mode, tissue Doppler S', fractional area change (FAC) and LASER. These measurements were compared to RVEF derived by CMR using Pearson's correlation coefficients and receiver operating characteristic curves. Results: LASER was measurable in 75 (96%) of patients within the cohort. Right ventricular systolic dysfunction, by CMR measurement, was present in 37% (n = 29) of the population. LASER has moderate positive correlation with RVEF (r = 0.54) which was similar to FAC (r = 0.56), S' (r = 0.49) and TAPSE (r = 0.37). Receiver operating characteristic curves demonstrated that LASER (AUC = 0.865) outperformed fractional area change (AUC = 0.767), tissue Doppler S' (AUC = 0.744) and TAPSE (AUC = 0.645). A cohort derived dichotomous cutoff of 0.2 for LASER was shown to provide optimal diagnostic characteristics (sensitivity of 75%, specificity of 87% and accuracy of 83%) for identifying abnormal RV function. LASER had the highest sensitivity, accuracy, positive and negative predictive values among the parameters studied in the cohort. Conclusions: Within the study cohort, LASER was shown to have moderate positive correlation with RVEF derived by CMR and more favorable diagnostic performance for detecting RV systolic dysfunction compared to conventional echocardiographic parameters while being simple to obtain and less dependent on image quality than FAC and emerging techniques.

Evaluation of echocardiographic derived parameters for right ventricular size and function using cardiac magnetic resonance imaging.

BACKGROUND: Cardiac Magnetic Resonance Imaging (cMRI) is the gold standard for right ventricular (RV) assessment due to its high spatial resolution. The American Society of Echocardiography (ASE) recommends eight structural and six functional quantitative parameters for evaluation of the RV. This study sought to simplify echocardiographic RV assessment by examining the relative diagnostic value of the echo recommended parameters by applying them to cMRI imaging of the RV. METHODS: We applied ASE recommended measures of RV size and function to 56 cMRI's and compared them to RV volumetric analysis obtained from cMRI. Pearsons' correlation coefficient was used to compare ASE prescribed parameters to corresponding cMRI calculated RV end diastolic volume (RVEDV) and RV ejection fraction (RVEF). The diagnostic performance of each parameter in predicting abnormal RV size or function was analyzed using receiver operator characteristic curves. Youden-J index was used to determine optimal sensitivity/specificity cut-points. Stepwise regression modeling was performed to identify measurements independently associated with RV size or RVEF. RESULTS: RV end diastolic area (RVEDA) correlated best with RVEDV (r = .76, p < 0.001) and RV fractional area change (RVFAC) correlated best with RVEF (r = .7, p < 0.001). The best ASE parameter for identifying RV dilatation was RVEDA (Youden-J index = .84), the optimal cutoff was 32.3 cm2 which yielded sensitivity/specificity of 84% and 100%, respectively. The best parameter for diagnosing RV dysfunction was RVFAC (Youden-J index = .52), with an optimal cutoff of 42% leading to sensitivity/specificity of 64% and 88%, respectively. CONCLUSION: The area based echocardiographic parameters for RV size and function, RVEDA and RV fractional area change outperform linear measurements in predicting RV dilation and RV systolic dysfunction. These parameters should be examined in further echocardiographic based studies as the primary parameters to guide quantitative RV assessment.

Relation of Venous Thromboembolism Risk to Ischemic Stroke Risk in Hospitalized Patients with Cancer.

Patients with cancer are at increased risk for venous thromboembolism (VTE). However, the relationship of cancer type to the risk of arterial thrombosis in patients with high VTE risk has not been described. The goal of this study is to determine the rate of arterial thrombosis in patients with different types of solid tumors stratified by VTE risk. Using the 2012 National Inpatient Sample, we identified 373,789 hospitalizations involving patients ≥18 years associated with solid tumors, stratified by type. Data were collected on clinical characteristics, VTE (deep vein thrombosis [DVT] and pulmonary embolism [PE]), and arterial thrombosis (primary diagnosis of myocardial infarction [MI] and ischemic stroke). Subjects with solid tumors (stages I to IV) were stratified by VTE risk - high versus low. Certain solid tumor types (esophageal, lung, melanoma, ovarian, pancreatic, stomach, and uterine) were found to be associated with a higher rate of VTE compared with other cancer types (6.8% vs 3.9%, p < 0.001). Multivariate analysis applied to the high VTE risk group showed no increased risk for MI (odds ratio [OR] 0.93, p = 0.74), however, the rate of ischemic stroke was increased (OR 1.22, p < 0.001). Those in the high VTE risk group who had metastatic disease were at higher risk for arterial thrombosis (MI OR 1.35, p < 0.001, ischemic stroke OR 2.43, p < 0.001). In conclusion, different cancer types are associated with increased risk of both venous and arterial thrombosis and the risk is further increased by the presence of metastatic disease.

Electromechanical and structural alterations in the aging rabbit heart and aorta.

Aging increases the risk for arrhythmias and sudden cardiac death (SCD). We aimed at elucidating aging-related electrical, functional, and structural changes in the heart and vasculature that account for this heightened arrhythmogenic risk. Young (5-9 mo) and old (3.5-6 yr) female New Zealand White (NZW) rabbits were subjected to in vivo hemodynamic, electrophysiological, and echocardiographic studies as well as ex vivo optical mapping, high-field magnetic resonance imaging (MRI), and histochemical experiments. Aging increased aortic stiffness (baseline pulse wave velocity: young, 3.54 ± 0.36 vs. old, 4.35 ± 0.28 m/s, P < 0.002) and diastolic (end diastolic pressure-volume relations: 3.28 ± 0.5 vs. 4.95 ± 1.5 mmHg/ml, P < 0.05) and systolic (end systolic pressure-volume relations: 20.56 ± 4.2 vs. 33.14 ± 8.4 mmHg/ml, P < 0.01) myocardial elastances in old rabbits. Electrophysiological and optical mapping studies revealed age-related slowing of ventricular and His-Purkinje conduction (His-to-ventricle interval: 23 ± 2.5 vs. 31.9 ± 2.9 ms, P < 0.0001), altered conduction anisotropy, and a greater inducibility of ventricular fibrillation (VF, 3/12 vs. 7/9, P < 0.05) in old rabbits. Histochemical studies confirmed an aging-related increased fibrosis in the ventricles. MRI showed a deterioration of the free-running Purkinje fiber network in ventricular and septal walls in old hearts as well as aging-related alterations of the myofibrillar orientation and myocardial sheet structure that may account for this slowed conduction velocity. Aging leads to parallel stiffening of the aorta and the heart, including an increase in systolic stiffness and contractility and diastolic stiffness. Increasingly, anisotropic conduction velocity due to fibrosis and altered myofibrillar orientation and myocardial sheet structure may contribute to the pathogenesis of VF in old hearts. The aging rabbit model represents a useful tool for elucidating age-related changes that predispose the aging heart to arrhythmias and SCD.

Stress-only or stress/rest myocardial perfusion imaging in patients undergoing evaluation for bariatric surgery.

BACKGROUND: Bariatric surgery for management of obesity is being used with increasing frequency. Stress testing with myocardial perfusion imaging is often employed as part of the workup prior to anticipated bariatric surgery. The incidence of clinically significant abnormalities on stress MPI performed for this indication, however, has not been established. METHODS AND RESULTS: We retrospectively reviewed a series of 383 consecutive stress MPI studies performed on patients undergoing workup prior to planned bariatric surgery. The study population had a mean age 42 ± 10 years, and was 83% female, with a body mass index of 49 ± 8. The majority of patients (81%) were able to exercise using either the Bruce or Modified Bruce protocol, and 67% underwent stress-only imaging. Overall SPECT MPI findings were normal in 89% and equivocal in 6% of patients. The incidence of abnormal findings on MPI was 5% (3% mild and 2% moderate-to-severe abnormalities). At 1 year, overall survival was 99.5%, with no difference between those with and without MPI abnormalities. Similarly, the incidence of post-operative cardiac events was very low (2%), and mostly due to atrial arrhythmias or borderline elevations of troponin. CONCLUSION: In a typical pre-bariatric surgery population, the incidence of abnormal stress MPI is low. The majority of patients were able to use a stress-only strategy for assessment of perfusion. At 1 year the incidence of adverse cardiovascular outcomes is very low. Additional studies should be focused on determining whether any subgroup of such patients may benefit more from pre-operative stress testing.