Risk predictors in a Spanish cohort with cardiac laminopathies. The REDLAMINA registry.

INTRODUCTION AND OBJECTIVES: According to sudden cardiac death guidelines, an implantable cardioverter-defibrillator (ICD) should be considered in patients with LMNA-related dilated cardiomyopathy (DCM) and ≥ 2 risk factors: male sex, left ventricular ejection fraction (LVEF) <45%, nonsustained ventricular tachycardia (NSVT), and nonmissense genetic variants. In this study we aimed to describe the clinical characteristics of carriers of LMNA genetic variants among individuals from a Spanish cardiac-laminopathies cohort (REDLAMINA registry) and to assess previously reported risk criteria. METHODS: The relationship between risk factors and cardiovascular events was evaluated in a cohort of 140 carriers (age ≥ 16 years) of pathogenic LMNA variants (54 probands, 86 relatives). We considered: a) major arrhythmic events (MAE) if there was appropriate ICD discharge or sudden cardiac death; b) heart failure death if there was heart transplant or death due to heart failure. RESULTS: We identified 11 novel and 21 previously reported LMNA-related DCM variants. LVEF <45% (P=.001) and NSVT (P <.001) were related to MAE, but not sex or type of genetic variant. The only factor independently related to heart failure death was LVEF <45% (P <.001). CONCLUSIONS: In the REDLAMINA registry cohort, the only predictors independently associated with MAE were NSVT and LVEF <45%. Therefore, female carriers of missense variants with either NSVT or LVEF <45% should not be considered a low-risk group. It is important to individualize risk stratification in carriers of LMNA missense variants, because not all have the same prognosis.

Contrast-Enhanced Echocardiographic Measurement of Left Ventricular Wall Thickness in Hypertrophic Cardiomyopathy: Comparison with Standard Echocardiography and Cardiac Magnetic Resonance.

BACKGROUND: Left ventricular wall thickness (LVWT) measurement is key in the diagnostic and prognostic assessment of hypertrophic cardiomyopathy (HCM). Recent investigations have highlighted discrepancies in LVWT by cardiac magnetic resonance (CMR) and standard echocardiography (S-Echo) in this condition. The aim of this study was to elucidate the role of contrast-enhanced echocardiography (C-Echo) to optimize LVWT measurement in patients with HCM. METHODS: Fifty patients with HCM were prospectively enrolled, undergoing S-Echo, C-Echo, and CMR. Blinded LVWT measurements were performed according to a 16-segment left ventricular model using all three imaging techniques. Agreement between both echocardiographic modalities and CMR (as the reference technique) at the segmental level was tested using Bland-Altman analyses. Reproducibility on segmental measurements by S-Echo and C-Echo was also investigated. RESULTS: Patients' mean age was 47 ± 21 years, and 35 (70%) were men. Maximal mean LVWT by S-Echo (20.1 ± 3.8 mm) was greater than the values derived using C-Echo (17.6 ± 4.0 mm, P < .01) and CMR (17.7 ± 4.5 mm, P < .01), with no statistically significant difference between the latter two. Segmental Bland-Altman models demonstrated globally smaller bias and narrower 95% limits of agreement for C-Echo compared with S-Echo. Across all left ventricular segments, LVWT by C-Echo was 2.4 mm lower (range, 1.0-2.5 mm) than that derived by S-Echo, which accounted for a 25% intertechnique difference. Regarding maximal LVWT, the mean absolute difference between C-Echo and S-Echo was 3.0 ± 1.9 mm (range, 0.0-7.9 mm), which represented a 15% intertechnique change. Data analyses demonstrated globally less intra- and interobserver variability in segmental LVWT derived from C-Echo compared with S-Echo. CONCLUSIONS: C-Echo rendered LVWT measurements closer to those derived by the reference technique (CMR) and improved reproducibility compared with S-Echo. C-Echo represents a suitable tool for LVWT measurement in patients with HCM as an alternative to CMR whenever this is not available or possible.

Structural abnormalities in hypertrophic cardiomyopathy beyond left ventricular hypertrophy by multimodality imaging evaluation.

BACKGROUND: Echocardiography- and cardiovascular magnetic resonance (CMR)-based studies have revealed a wide range of phenotypic manifestations in hypertrophic cardiomyopathy (HCM) apart from hypertrophy. This study sought to comprehensively describe a number of structural abnormalities in HCM beyond hypertrophy, by multimodality imaging. METHODS: A total of 100 HCM patients were prospectively enrolled, undergoing standard and contrast echocardiography, and CMR. Morphological characteristics involving mitral valve leaflets (MVL), subvalvular apparatus, and left ventricular cavity and wall were investigated. Seventy healthy volunteers served as control population. RESULTS: As assessed by echo, MVLs were longer in HCM patients than in controls (anterior method 1: 24[22,28] vs 19[18,20] mm, P < 0.01; anterior method 2: 27[24, 29] vs 21[19, 23] mm, P < 0.01; posterior: 15[12,19] vs 14[13,15] mm, P < 0.01). Abnormal chordal attachment to anterior MVL, anterior papillary muscle displacement, and accessory apical-basal muscle bundle were present in 42 (42%), 61 (61%), and 35 (35%) patients, respectively (P values vs controls <0.01); direct papillary muscle insertion into MVL and hypertrabeculation were found in two and five patients, respectively. Contrast echocardiography (n = 94) detected myocardial crypts in 15 patients (16%). Overall, 83% of HCM subjects had at least one of these phenotypic manifestations. Echocardiography and CMR agreement for MVL length was poor, while for structural characteristics was moderate to substantial (Cohen's Kappa: 0.53-1.00). Except for posterior MVL length and hypertrabeculation, the phenotypic characteristics studied had acceptable reproducibility by echocardiography and CMR. CONCLUSIONS: Structural abnormalities in HCM beyond hypertrophy are significantly common. Multimodality imaging approach to these HCM facets by echocardiography and CMR is feasible and desirable.

Aortic flow patterns and wall shear stress maps by 4D-flow cardiovascular magnetic resonance in the assessment of aortic dilatation in bicuspid aortic valve disease.

BACKGROUND: In patients with bicuspid valve (BAV), ascending aorta (AAo) dilatation may be caused by altered flow patterns and wall shear stress (WSS). These differences may explain different aortic dilatation morphotypes. Using 4D-flow cardiovascular magnetic resonance (CMR), we aimed to analyze differences in flow patterns and regional axial and circumferential WSS maps between BAV phenotypes and their correlation with ascending aorta dilatation morphotype. METHODS: One hundred and one BAV patients (aortic diameter ≤ 45 mm, no severe valvular disease) and 20 healthy subjects were studied by 4D-flow CMR. Peak velocity, flow jet angle, flow displacement, in-plane rotational flow (IRF) and systolic flow reversal ratio (SFRR) were assessed at different levels of the AAo. Peak-systolic axial and circumferential regional WSS maps were also estimated. Unadjusted and multivariable adjusted linear regression analyses were used to identify independent correlates of aortic root or ascending dilatation. Age, sex, valve morphotype, body surface area, flow derived variables and WSS components were included in the multivariable models. RESULTS: The AAo was non-dilated in 24 BAV patients and dilated in 77 (root morphotype in 11 and ascending in 66). BAV phenotype was right-left (RL-) in 78 patients and right-non-coronary (RN-) in 23. Both BAV phenotypes presented different outflow jet direction and velocity profiles that matched the location of maximum systolic axial WSS. RL-BAV velocity profiles and maximum axial WSS were homogeneously distributed right-anteriorly, however, RN-BAV showed higher variable profiles with a main proximal-posterior distribution shifting anteriorly at mid-distal AAo. Compared to controls, BAV patients presented similar WSS magnitude at proximal, mid and distal AAo (p = 0.764, 0.516 and 0.053, respectively) but lower axial and higher circumferential WSS components (p < 0.001 for both, at all aortic levels). Among BAV patients, RN-BAV presented higher IRF at all levels (p = 0.024 proximal, 0.046 mid and 0.002 distal AAo) and higher circumferential WSS at mid and distal AAo (p = 0.038 and 0.046, respectively) than RL-BAV. However, axial WSS was higher in RL-BAV compared to RN-BAV at proximal and mid AAo (p = 0.046, 0.019, respectively). Displacement and axial WSS were independently associated with the root-morphotype, and circumferential WSS and SFRR with the ascending-morphotype. CONCLUSIONS: Different BAV-phenotypes present different flow patterns with an anterior distribution in RL-BAV, whereas, RN-BAV patients present a predominant posterior outflow jet at the sinotubular junction that shifts to anterior or right anterior in mid and distal AAo. Thus, RL-BAV patients present a higher axial WSS at the aortic root while RN-BAV present a higher circumferential WSS in mid and distal AAo. These results may explain different AAo dilatation morphotypes in the BAV population.