Prognostic value of left ventricular remodelling index in idiopathic dilated cardiomyopathy

AIMS

To evaluate the prognostic value of left ventricular (LV) remodelling index (RI) in idiopathic dilated cardiomyopathy (DCM) patients.

METHODS AND RESULTS

We prospectively enrolled 412 idiopathic DCM patients and 130 age- and sex-matched healthy volunteers who underwent cardiovascular magnetic resonance imaging between September 2013 and March 2018. RI was defined as the cubic root of the LV end-diastolic volume divided by the mean LV wall thickness on basal short-axis slice. The primary endpoint included all-cause mortality and heart transplantation. The secondary endpoint included the primary endpoint and heart failure (HF) readmission. During the median follow-up of 28.1 months (interquartile range: 19.3-43.0 months), 62 (15.0%) and 143 (34.7%) patients reached the primary and secondary endpoints, respectively. Stepwise multivariate Cox regression showed that RI [hazard ratio (HR) 1.20, 95% confidence interval (CI) 1.11-1.30, P < 0.001], late gadolinium enhancement (LGE) presence and log (N-terminal pro-B-type natriuretic peptide) were independent predictors of the primary endpoint, while RI (HR 1.15, 95% CI 1.08-1.23, P < 0.001) and extracellular volume were independent predictors of the secondary endpoint. The addition of RI to LV ejection fraction (EF) and LGE presence showed significantly improved global χ2 for predicting primary and secondary endpoints (both P < 0.001). Furthermore, RI derived from echocardiography also showed independent prognostic value for primary and secondary endpoints with clinical risk factors.

CONCLUSIONS

RI is an independent predictor of all-cause mortality, heart transplantation, and HF readmission in DCM patients and provides incremental prognostic value to LVEF and LGE presence.

Advanced Imaging of Athletes: Added Value of Coronary Computed Tomography and Cardiac Magnetic Resonance Imaging

Cardiac magnetic resonance imaging and cardiac computed tomographic angiography have become important parts of the armamentarium for noninvasive diagnosis of cardiovascular disease. Emerging technologies have produced faster imaging, lower radiation dose, improved spatial and temporal resolution, as well as a wealth of prognostic data to support usage. Investigating true pathologic disease as well as distinguishing normal from potentially dangerous is now increasingly more routine for the cardiologist in practice. This article investigates how advanced imaging technologies can assist the clinician when evaluating all athletes for pathologic disease that may put them at risk.

Cardiomyopathies (hypertrophy and failure): what can offer cardiac magnetic resonance imaging?

In routine, cardiomyopathy, confirmed or not, is a frequent reason for cardiac MRI evaluation. Step by step, by using a wide panel of sequences, cardiac MRI is able to characterize cardiomyopathies by their morphologic and functional phenotype as well as by tissue characterization. Cardiac-MRI is also considered as the most appropriate technique for the follow-up of this disease. The purpose of this article is to browse an overview of the main MRI features of cardiomyopathy, focusing the purpose on hypertrophic forms and myocardial diseases leading to cardiac failure.

Late gadolinium enhanced cardiovascular magnetic resonance of lamin A/C gene mutation related dilated cardiomyopathy

BACKGROUND

The purpose of this study was to identify early features of lamin A/C gene mutation related dilated cardiomyopathy (DCM) with cardiovascular magnetic resonance (CMR). We characterise myocardial and functional findings in carriers of lamin A/C mutation to facilitate the recognition of these patients using this method. We also investigated the connection between myocardial fibrosis and conduction abnormalities.

METHODS

Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium enhancement (LGE) and cine images were performed to evaluate myocardial fibrosis, regional wall motion, longitudinal myocardial function, global function and volumetry of both ventricles. The location, pattern and extent of enhancement in the left ventricle (LV) myocardium were visually estimated.

RESULTS

Patients had LV myocardial fibrosis in 88% of cases. Segmental wall motion abnormalities correlated strongly with the degree of enhancement. Myocardial enhancement was associated with conduction abnormalities. Sixty-nine percent of our asymptomatic or mildly symptomatic patients showed mild ventricular dilatation, systolic failure or both in global ventricular analysis. Decreased longitudinal systolic LV function was observed in 53% of patients.

CONCLUSIONS

Cardiac conduction abnormalities, mildly dilated LV and depressed systolic dysfunction are common in DCM caused by a lamin A/C gene mutation. However, other cardiac diseases may produce similar symptoms. CMR is an accurate tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy and may help to initiate early treatment in this malignant familiar form of DCM.

Evaluation of left ventricular enlargement as a marker of early disease in familial dilated cardiomyopathy

BACKGROUND

Echocardiographic screening of families with dilated cardiomyopathy has identified a subgroup of asymptomatic relatives with left ventricular enlargement (LVE). The prognostic significance of LVE in this setting is incompletely understood.

METHODS AND RESULTS

We evaluated 457 asymptomatic relatives in 128 dilated cardiomyopathy families and identified 110 individuals (24%) with LVE. Serial echocardiograms in 72 untreated LVE relatives showed that 9 individuals (13%) had development of dilated cardiomyopathy over 10 to 152 months (median, 52). Thirty LVE relatives and 30 age- and sex-matched healthy control subjects were evaluated using 2-dimensional and M-mode echocardiography, tissue Doppler imaging, noninvasive pressure-volume assessment, exercise stress echocardiography, and brain natriuretic peptide levels. LVE relatives showed mild defects of systolic and diastolic LV function, with normal filling pressures and exercise-induced increments in systolic contraction in most cases. LV dimensions and fractional shortening most effectively differentiated LVE relatives from control subjects, with other functional indices lacking additive discriminative value. In a receiver operating characteristics analysis, the area under the curve for LV end-diastolic diameter (% predicted) was 0.96 (P<0.001). LV end-diastolic diameter (% predicted) >116% or LV end-diastolic diameter (% predicted) 112% to 116%+fractional shortening ≤29% had high sensitivity (100%) and specificity (93%) for LVE relatives and identified 8 of 9 progressors.

CONCLUSIONS

LVE is a common finding in asymptomatic relatives in dilated cardiomyopathy families and can be a marker of preclinical cardiomyopathy. Assessment of LV size and contractile function is required for differentiating between pathological and physiological causes of LVE and may help to identify those at risk of disease progression.

Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy

Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance.

Early changes in right ventricular function and their clinical consequences in childhood and adolescent dilated cardiomyopathy

The aim of the paper was to investigate the right ventricle in paediatric dilated cardiomyopathy. We examined 11 patients with dilated cardiomyopathy as well as 12 normal paediatric controls. Cardiac magnetic resonance imaging was performed for ventricular size and function. N-terminal pro-brain natriuretic peptide was collected at this time and the results from the most recent echocardiogram and exercise test were reviewed.We found that patients with dilated cardiomyopathy had significantly faster heart rates, that is, 85 versus 65 beats per minute, lower left ventricular ejection fraction, that is, 42 versus 61%, and right ventricular ejection fraction of 44 versus 54%, lower left and right ventricular stroke volumes, that is, 35.5 versus 49.5 millilitres per square metre and 40.9 versus 56.4 millilitres per square metre, respectively, and lower mitral and tricuspid valve inflow e/a wave velocity ratios of 2.02 versus 2.80 and 1.25 versus 2.58, respectively, than the controls. Tricuspid valve annulus velocity, measured by tissue Doppler echocardiography, correlated with right ventricular ejection fraction (r = 0.60, p = 0.05). Right ventricular ejection fraction and indexed right ventricular end-diastolic volume correlated with N-terminal pro-brain natriuretic peptide (r = -0.67, p = 0.03, r = 0.65, p = 0.04, respectively), and right ventricular ejection fraction correlated with the oxygen uptake at the anaerobic threshold (r = 0.67, p = 0.049). Neither left ventricular ejection fraction nor left ventricular volume correlated with N-terminal pro-brain natriuretic peptide or exercise tolerance. The right ventricular function is decreased in the early stages of dilated cardiomyopathy. Right ventricular size and ejection fraction may be important indicators of sub-clinical cardiac failure and we suggest monitoring them routinely in dilated cardiomyopathy.

Lamin A/C deficiency as a cause of familial dilated cardiomyopathy

PURPOSE OF REVIEW

Familial dilated cardiomyopathy is an underrecognized form of dilated cardiomyopathy. Lamin A/C deficiency is probably the most common cause of familial dilated cardiomyopathy. This review will focus on the emerging knowledge of epidemiology, diagnosis, and treatment of patients with lamin A/C deficiency, as well as possible disease mechanisms.

RECENT FINDINGS

Screening of patients with dilated cardiomyopathy continues to indicate that lamin A/C deficiency is a significant cause. Multiple novel mutations have been found, suggesting that many mutations are limited to individuals or families. It is unknown how mutations cause the syndrome, although an animal model has shown that lamin A/C insufficiency causes apoptosis, particularly in the conduction system. Inheritance is predominantly autosomal dominant, but penetrance is variable. For symptomatic patients, the course is malignant, with conduction system disease, atrial fibrillation, heart failure, and sudden cardiac death. The data are contradictory, and currently, there is no clear marker for when a lamin A/C-deficient patient is at risk for sudden death.

SUMMARY

Lamin A/C deficiency is an important cause of dilated cardiomyopathy, and diagnosis requires that clinicians have a high index of suspicion. Our knowledge of the mechanisms, diagnosis, and treatment of lamin A/C deficiency is incomplete. It is clear that patients with this condition have a malignant course and need to be followed aggressively.