Cardiac amyloidosis in non-transplant cardiac surgery

Cardiac amyloidosis is a rare infiltrative cardiomyopathy that portends a poor prognosis. There is a growing recognition of co-existent aortic valve stenosis and transthyretin cardiac amyloidosis, with some studies suggesting that dual pathology may be associated increased risk of complication and mortality during surgical intervention. This review aims to evaluate the available literature on non-transplant cardiac surgical interventions in patients with cardiac amyloidosis, with particular focus on diagnosis, high surgical risk and areas of uncertainty that require further research

Heart failure and excess mortality after aortic valve replacement in aortic stenosis

INTRODUCTION: In aortic stenosis (AS), the heart transitions from adaptive compensation to an AS cardiomyopathy and eventually leads to decompensation with heart failure. Better understanding of the underpinning pathophysiological mechanisms is required in order to inform strategies to prevent decompensation. AREAS COVERED: In this review, we therefore aim to appraise the current pathophysiological understanding of adaptive and maladaptive processes in AS, appraise potential avenues of adjunctive therapy before or after AVR and highlight areas of further research in the management of heart failure post AVR. EXPERT OPINION: Tailored strategies for the timing of intervention accounting for individual patient's response to the afterload insult are underway, and promise to guide better management in the future. Further clinical trials of adjunctive pharmacological and device therapy to either cardioprotect prior to intervention or promote reverse remodelling and recovery after intervention are needed to mitigate the risk of heart failure and excess mortality

Myocardial extracellular volume quantification by cardiovascularagn magnetic resonance and computed tomography

Purpose of review This review article discusses the evolution of extracellular volume (ECV) quantification using both cardiovascular magnetic resonance (CMR) and computed tomography (CT). Recent findings Visualizing diffuse myocardial fibrosis is challenging and until recently, was restricted to the domain of the pathologist. CMR and CT both use extravascular, extracellular contrast agents, permitting ECV measurement. The evidence base around ECV quantification by CMR is growing rapidly and just starting in CT. In conditions with high ECV (amyloid, oedema and fibrosis), this technique is already being used clinically and as a surrogate endpoint. Non-invasive diffuse fibrosis quantification is also generating new biological insights into key cardiac diseases. Summary CMR and CT can estimate ECV and in turn diffuse myocardial fibrosis, obviating the need for invasive endomyocardial biopsy. CT is an attractive alternative to CMR particularly in those individuals with contraindications to the latter. Further studies are needed, particularly in CT

A case report in cardiovascular magnetic resonance: the contrast agent matters in amyloid

BACKGROUND: Cardiac amyloidosis is a progressive but underdiagnosed and underappreciated cause of heart failure. In the last few years, cardiovascular magnetic resonance (CMR) has become the gold standard for non invasive diagnosis of cardiac amyloidosis with the characteristic subendocardial late gadolinium enhancement. CASE PRESENTATION: We describe a case of a patient who, in the process of aligning protocols for a trial between different centers, had a paired study with two different contrast agents, Dotarem® and MultiHance®. MultiHance® surprisingly failed to demonstrate the characteristic imaging pattern, showing only non specific late gadolinium enhancement at the inferior right ventricular insertion point and different myocardial extracellular volume fraction compared to the one obtained with Dotarem®. MultiHance® is used by many centres, because its partial blood protein binding is a strength for MR angiography, but late gadolinium enhancement, particularly non-ischemic, appears to be compromised. CONCLUSIONS: This case report suggests that contrast agents should be selected with caution, especially with new therapies lining up for amyloid and CMR being used as exploratory end point in clinical trials

Natriuretic peptide release during exercise in patients with valvular heart disease: A systematic review

Aim: Serum biomarkers have a potential role in the risk stratification of patients with heart valve disease and may help determine the optimal timing of intervention. Much of the published literature relates to biomarker sampling in a resting state, but the relationship of exercise biomarkers is less well described. We performed a systematic review to examine the significance of exercise natriuretic peptides on echocardiographic variables and cardiovascular events, in valvular heart disease. / Methods: A search for studies that assessed exercise biomarkers in patients with moderate to severe valve lesions was performed. We examined the relationship between rest and exercise BNP and also the endpoints of symptoms, haemodynamic or echocardiographic variables and clinical outcomes. / Results: Eleven prospective studies were identified (844 participants). 61% were male and the mean age was 55.2 ± 9.6 years. The majority of the blood samples were taken at baseline and within 3 minutes of stopping exercise. There was a significant increase in exercise BNP compared with rest, in patients with aortic stenosis, mitral regurgitation and mitral stenosis. Elevated exercise BNP levels correlated with mean gradient and left atrial area, and there was a relationship between a higher exercise BNP and a blunted blood pressure response, in aortic stenosis. Furthermore, exercise BNP was independently associated with cardiac events, over and above resting values, in patients with mitral regurgitation and aortic stenosis. / Conclusion: The results suggesting that exercise natriuretic peptide levels may have additive prognostic importance over resting levels, as well as demographic and echocardiographic data

Myocardial Approximate Spin-lock Dispersion Mapping using a Simultaneous T2 and TRAFF2 Mapping at 3T MRI

Ischemic heart disease (IHD) is one of the leading causes of death worldwide. Myocardial infarction (MI) represents a third of all IHD cases, and cardiac magnetic resonance imaging (MRI) is often used to assess its damage to myocardial viability. Late gadolinium enhancement (LGE) is the current gold standard, but the use of gadolinium-based agents limits the clinical applicability in some patients. Spin-lock (SL) dispersion has recently been proposed as a promising non-contrast biomarker for the assessment of MI. However, at 3T, the required range of SL preparations acquired at different amplitudes suffers from specific absorption rate (SAR) limitations and off-resonance artifacts. Relaxation Along a Fictitious Field (RAFF) is an alternative to SL preparations with lower SAR requirements, while still sampling relaxation in the rotating frame. In this study, a single breath-hold simultaneous TRAFF2 and T2 mapping sequence is proposed for SL dispersion mapping at 3T. Excellent reproducibility (coefficient of variations lower than 10%) was achieved in phantom experiments, indicating good intrascan repeatability. The average myocardial TRAFF2, T2, and SL dispersion obtained with the proposed sequence (68.0±10.7 ms, 44.0±4.0 ms, and 0.4±0.2 ×10-4 s2, respectively) were comparable to the reference methods (62.7±11.7 ms, 41.2±2.4 ms, and 0.3±0.2x 10-4s2, respectively). High visual map quality, free of B0 and B1+ related artifacts, for T2, TRAFF2, and SL dispersion maps were obtained in phantoms and in vivo, suggesting promise in clinical use at 3T. Clinical relevance - and imaging promises non-contrast assessment of scar and focal fibrosis in a single breath-hold using approximate spin-lock dispersion mapping

Texture Analysis of Cardiovascular Magnetic Resonance Cine Images differentiates etiologies of left ventricular hypertrophy

BACKGROUND: Textural analysis (TA) shows promise as radiological biomarker. The use of native TA in the field of cardiology is unproven. We hypothesized that Cardiovascular Magnetic Resonance pre-contrast bSSFP cine images could be analysed using TA software; TA features would differentiate different aetiologies of disease causing increased myocardial wall thickness (left ventricular hypertrophy {LVH}) and indicate the severity of myocardial tissue abnormality. METHOD: A mid short axis pre-contrast cine frame of 216 cases (50 hypertrophic cardiomyopathy (predominantly LVOTO sub type) (HCM), 52 cardiac amyloid (predominantly AL sub-type) (CA), 68 aortic stenosis (AS), 15 hypertensive with LVH (HTN+LVH) and 31 healthy volunteers (HV)) underwent CMRTA using TexRAD (TexRAD Ltd, Cambridge, UK). Among HV, 16/ 31 were scanned twice to form a test-retest reproducibility cohort. CMRTA comprised a filtration-histogram technique to extract and quantify features using 6 parameters. RESULTS: Test-retest analysis in HV showed a medium filter (3mm) was the most reproducible (intra-class correlation of 0.9 for kurtosis and skewness and 0.8 for mean and SD). Disease cohorts were statistically different (p<0.001) to health for all parameters. Pair wise comparisons of CMRTA parameters showed kurtosis and skewness consistently significant in ranking degree of difference from HV (greatest to least); CA, HCM, LVH+HTN, AS (p<0.001). Similarly mean, SD, entropy and mean positive pixel (MPP) were consistent in ranking degree of difference from HV; HCM, CA, AS and HTN+LVH. CONCLUSION: Radiomic features of bSSFP CMR data sets, derived using TA, show promise in discriminating between aetiologies of LVH