Dermot Phelan

Relative apical sparing of longitudinal strain using two-dimensional speckle-tracking echocardiography is both sensitive and specific for the diagnosis of cardiac amyloidosis

Background The diagnosis of cardiac amyloidosis (CA) is challenging owing to vague symptomatology and non-specific echocardiographic findings. Objective To describe regional patterns in longitudinal strain (LS) using two-dimensional speckle-tracking echocardiography in CA and to test the hypothesis that regional differences would help differentiate CA from other causes of increased left ventricular (LV) wall thickness. Methods and results 55 consecutive patients with CA were compared with 30 control patients with LV hypertrophy (n=15 with hypertrophic cardiomyopathy, n=15 with aortic stenosis). A relative apical LS of 1.0, defined using the equation (average apical LS/(average basal LS + mid-LS)), was sensitive (93%) and specific (82%) in differentiating CA from controls (area under the curve 0.94). In a logistic regression multivariate analysis, relative apical LS was the only parameter predictive of CA (p=0.004). Conclusions CA is characterised by regional variations in LS from base to apex. A relative ‘apical sparing’ pattern of LS is an easily recognisable, accurate and reproducible method of differentiating CA from other causes of LV hypertrophy.

Accuracy of Wrist-Worn Heart Rate Monitors

Accuracy of Wrist-Worn Heart Rate Monitors Wrist-worn fitness and heart rate (HR) monitors are popular.1,2 While the accuracy of chest strap, electrode-based HR monitors has been confirmed,3,4 the accuracy of wrist-worn, optically based HR monitors is uncertain.5,6 Assessment of the monitors’ accuracy is important for individuals who use them to guide their physical activity and for physicians to whom these individuals report HR readings. The objective of this study was to assess the accuracy of 4 popular wrist-worn HR monitors under conditions of varying physical exertion.

Quantitative Assessment of Mitral Regurgitation: How Best to Do It

Decisions regarding surgery for mitral regurgitation (MR) are predicated on the accurate quantification of MR severity. Quantitative parameters, including vena contracta width, regurgitant volume and fraction, and effective regurgitant orifice area have prognostic significance and are recommended to be obtained from patients with more than mild MR. New tools for MR quantification have been provided by 3-dimensional echocardiography, cardiac magnetic resonance, and cardiac computed tomography, but limited guidance on appropriate image acquisition and post-processing techniques has hindered their clinical application and reproducibility. This review describes optimal image acquisition and post-processing methods for quantification of MR.

Quantitative assessment of mitral regurgitation: validation of new methods.

Accurate assessment of mitral regurgitation (MR) severity is important for clinical decision making, prognostication, and decisions regarding timing of surgical intervention. The most common method for noninvasive assessment of MR has been with 2-dimensional transthoracic echocardiography, which is often used as a qualitative tool. Several newer noninvasive modalities including 3-dimensional echocardiography, cardiac magnetic resonance imaging, and cardiac computed tomography have also become available for this purpose; however, their role in routine clinical practice is not clearly defined. In this review, we provide an overview of these newer modalities for quantitative assessment of MR severity.

Isolated left ventricular non-compaction controversies in diagnostic criteria, adverse outcomes and management

Isolated left ventricular non-compaction (LVNC) is a morphological abnormality of excessive trabeculation of the LV, often complicated by ventricular dysfunction, arrhythmias and cardioembolism. Advances in cardiovascular imaging and widespread availability of imaging technology have led to an increase in the diagnosis of LVNC imposing a need for evidence-based imaging diagnostic criteria. Although recent studies have addressed the utility of newer diagnostic methodologies and the incidence of adverse events in this condition, the diagnosis and management remain controversial. In this review, we provide an overview of the current controversies in the clinical diagnosis of LVNC, and suggest a management approach.

Role of imaging in the diagnosis and management of patients with cardiac amyloidosis: State of the art review and focus on emerging nuclear techniques

Amyloidosis is an infiltrative disease characterized by deposition of amyloid fibrils within the extracellular tissue of one or multiple organs. Involvement of the heart, cardiac amyloidosis, is recognized as a common cause of restrictive cardiomyopathy and heart failure. The two major types of cardiac amyloidosis are cardiac amyloid light-chain (AL) and transthyretin-related cardiac amyloidosis (ATTR, mutant and wild types) (Nat Rev Cardiol 2010;7:398-408). While early recognition of cardiac amyloidosis is of major clinical importance, so is the ability to differentiate between subtypes. Indeed, both prognosis and therapeutic options vary drastically depending on the subtype. While endomyocardial biopsy with immunostaining is considered the gold standard, advances in imaging provide an attractive non-invasive alternative. Currently, electrocardiography, echocardiography, and cardiac magnetic resonance imaging are all used in the evaluation of cardiac amyloidosis with varying diagnostic and prognostic accuracy. Yet, none of these modalities can effectively differentiate the cardiac amyloid subtypes. Recent data with 99mTc-phosphate derivatives, previously used as bone seeking radioactive tracers, have shown promising results; these radiotracers selectively bind ATTR, but not AL subtype, and can differentiate subtypes with high diagnostic accuracy. This review will initially present the non-radionuclide imaging techniques and then focus on the radionuclide imaging techniques, particularly 99mTc-DPD and 99mTc-PYP, mechanism of action, performance and interpretation of the study, diagnostic accuracy, prognostic value, future clinical perspective, and outlook.

Prognostic implication of relative regional strain ratio in cardiac amyloidosis

Objective Cardiac amyloidosis (CA) is a rapidly progressive disease that portends poor prognosis. Our objective was to evaluate the prognostic impact of relative regional strain ratio (RRSR, a measure of the relative apical sparing of longitudinal strain (LS)) in CA. Methods This is a retrospective study evaluating 97 patients with CA from 2004 to 2013. Patients were included if they met criteria for CA based on endomyocardial biopsy or advanced imaging criteria coupled with either extracardiac biopsy or genetic analysis. Baseline clinical and imaging data were collected and compared between light-chain amyloidosis (AL) (n=59) and transthyretin amyloidosis (ATTR) (n=38) subtypes. RRSR was defined as the average apical LS divided by the sum of the average mid and basal LS values. A Cox proportional hazards model was used to assess the effects of clinical and echocardiographic characteristics, including RRSR, on the outcome of time to death or heart transplantation. Results Despite younger age, the AL subtype had a statistically significant association with the composite outcome as compared with ATTR (p=0.022). Log-transformed RRSR was independently associated with the composite outcome at 5 years (HR 2.45 (1.36 to 4.40), p=0.003). Patients with low ejection fraction and high RRSR had the worst prognosis. In multivariable analysis, RRSR remained predictive of the primary outcome (p=0.018). Addition of covariates related to systolic function (global LS and ejection fraction) to the model attenuated this effect. Conclusions High RRSR is adversely prognostic in patients with cardiac amyloid. This novel tool is both diagnostic and prognostic and may have implications in management and suitability for treatment.

Aldosterone antagonists improve ejection fraction and functional capacity independently of functional class: a meta-analysis of randomised controlled trials

Context Current guidelines recommend the use of aldosterone antagonists (AA) in patients with moderately severe to severe symptoms [New York Heart Association (NYHA) class III to IV] and systolic heart failure. Objective To determine the efficacy of AA in improving ejection fraction (EF) and functional capacity and to assess whether this effect was influenced by baseline NYHA classification. Study design Meta-analysis of randomized controlled trials. Data extraction performed independently by two researchers. Data Sources MEDLINE and the Cochrane Library. Study Selection Prospective randomized controlled trials using AA were included if there was a clear description of the baseline NYHA classification and change in EF in patients from study initiation to completion. Results Data from 1,575 patients enrolled in fourteen studies were included. Overall, there was a weighted mean improvement in EF of 3.2% and in NYHA classification of 0.13 in subjects treated with AA when compared to controls (p<0.001). A mixed effects meta-regression analysis revealed that baseline NYHA was not predictive of improvement in EF (p=0.67) nor NYHA status (p=0.18). Conclusions The results of this meta-analysis suggest that AA is associated with significant improvements in EF and functional class independent of baseline functional capacity. This supports and expands on the recently published EMPHASIS-HF trial and suggests that the current restriction of AA use to patients with NYHA class III-IV symptoms should be reconsidered.

Application of a parametric display of two-dimensional speckle-tracking longitudinal strain to improve the etiologic diagnosis of mild to moderate left ventricular hypertrophy.

BACKGROUND The distinction of hypertrophic cardiomyopathy (HCM) or cardiac amyloidosis (CA) from hypertensive heart disease may be difficult. The aim of this study was to determine the impact of parametric (polar) maps of regional longitudinal strain on identification of the etiology of mild to moderate left ventricular hypertrophy (LVH). METHODS Twenty-four consecutive echocardiographic studies with mild to moderate LVH (eight with CA, eight with HCM, and eight with hypertensive heart disease) were selected on the basis of the availability of adequate images to assess longitudinal strain and absence of electrocardiographic criteria for low voltage or LVH or a pseudoinfarct pattern. Twenty level 3-trained readers provided the most likely of three diagnoses (CA, HCM, or hypertensive heart disease) and scored their confidence in making the diagnosis from two-dimensional images and diastolic parameters. A teaching exercise was provided on the interpretation of longitudinal strain in these cohorts, and interpretation was repeated with the addition of the strain polar map. RESULTS Baseline concordance among the readers was poor (κ = 0.28) and improved with the addition of strain data (κ = 0.57). Accuracy was improved with the addition of polar maps for the entire study cohort (P < .001), with 22% of cases reclassified correctly. The largest improvements in sensitivity (from 40% to 86%, P < .001), specificity (from 84% to 95%, P < .001), and accuracy (from 70% to 92%, P < .001) were seen for CA. The strain polar map significantly improved reader confidence in making the correct diagnosis overall (P < .001). CONCLUSIONS Regional variations in strain are easily recognizable, accurate, and reproducible means of differentiating causes of LVH. The detection of LVH etiology may be a useful clinical application for strain.

Congenital Absence of the Left Atrial Appendage

A 73-year-old woman with no history of cardiac surgery presented with symptomatic atrial fibrillation. A transesophageal echocardiogram was scheduled to exclude thrombus before cardioversion. No obvious intracardiac thrombus was identified, but the patient could not be cleared for cardioversion because the left atrial appendage (LAA) had not been visualized, raising concerns for either a flush occlusion with thrombus or a small ectopic appendage (Figure 1 and online-only Data Supplement Videos I-IV). Contrast-enhanced multidetector computed tomography revealed moderate biatrial enlargement without intracardiac thrombus and confirmed a diagnosis of …