MRI and LV Remodelling in Cardiac Amyloidosis
Background Cardiac amyloidosis (CA) is associated with typical morphological features on echocardiography, including concentric LV hypertrophy (LVH). Cardiac magnetic resonance (CMR) can accurately depict anatomy in different cardiomyopathies. Our aim was to describe the morphological features and remodelling patterns of CA with CMR, and establish their diagnostic accuracy, as well as the value of traditional diagnostic criteria derived from echocardiography and electrocardiography.
Methods Consecutive patients referred for CMR for possible CA were retrospectively evaluated. The diagnosis of CA was established in the presence of a positive cardiac biopsy and/or a typical pattern of myocardial late gadolinium enhancement. Morphological parameters were obtained from standard cine sequences. The presence and distribution of LVH, relative wall thickness (RWT) and LV remodelling patterns were determined.
Results 130 patients (92 males (70.8%), age 64±13 years) were included. CA was diagnosed in 51 (39.2%). Patients with CA had increased LV wall thickness and LV mass index. An LV remodelling pattern different from concentric LVH was found in 42% of patients with CA, and asymmetric LVH was noted in 68.6%. A model including RWT, asymmetric LVH, and LVMI showed diagnostic accuracy of 88%, sensitivity of 67% and specificity of 86% for CA detection. Traditional diagnostic criteria for CA showed high specificity but poor sensitivity.
Conclusions Asymmetric LVH and remodelling patterns different from concentric LVH are common in CA. Increased LV mass index, increased RWT, and asymmetric LVH are independently associated with the diagnosis. Traditional diagnostic criteria show poor sensitivity.
Cardiac amyloidosis (CA) is definitely diagnosed by the pathological demonstration of extracellular amyloid deposition in the myocardium. However, endomyocardial biopsy (EMB) is not widely available due to its invasive nature. Thus, EMB is frequently omitted in the presence of typical echocardiographic findings and extracardiac histological confirmation of amyloidosis. Although concentric LV hypertrophy (LVH) is commonly seen echocardiografically, it is not specific and may indicate end-stage disease. The presence of low voltage on the ECG has increased specificity, but still lacks sensitivity in early stages.
Recently, the presence of a typical pattern on late gadolinum enhancement (LGE) with cardiac magnetic resonance (CMR) has demonstrated variable sensitivity (69–97%) but particularly high specificity (94%) compared to EMB. Even without contrast, CMR may be an attractive alternative to echocardiography due to its more precise characterisation of tridimensional morphological and geometric changes in different cardiomyopathies. However, there is limited data on LV morphological and remodelling patterns with CMR in CA.
We hypothesise that CMR can characterise these parameters and that they provide diagnostic value for the detection of CA in a contemporary population referred for CMR. We also evaluated the accuracy of 'traditional' diagnostic criteria.
Abstract and Introduction
Abstract
Background Cardiac amyloidosis (CA) is associated with typical morphological features on echocardiography, including concentric LV hypertrophy (LVH). Cardiac magnetic resonance (CMR) can accurately depict anatomy in different cardiomyopathies. Our aim was to describe the morphological features and remodelling patterns of CA with CMR, and establish their diagnostic accuracy, as well as the value of traditional diagnostic criteria derived from echocardiography and electrocardiography.
Methods Consecutive patients referred for CMR for possible CA were retrospectively evaluated. The diagnosis of CA was established in the presence of a positive cardiac biopsy and/or a typical pattern of myocardial late gadolinium enhancement. Morphological parameters were obtained from standard cine sequences. The presence and distribution of LVH, relative wall thickness (RWT) and LV remodelling patterns were determined.
Results 130 patients (92 males (70.8%), age 64±13 years) were included. CA was diagnosed in 51 (39.2%). Patients with CA had increased LV wall thickness and LV mass index. An LV remodelling pattern different from concentric LVH was found in 42% of patients with CA, and asymmetric LVH was noted in 68.6%. A model including RWT, asymmetric LVH, and LVMI showed diagnostic accuracy of 88%, sensitivity of 67% and specificity of 86% for CA detection. Traditional diagnostic criteria for CA showed high specificity but poor sensitivity.
Conclusions Asymmetric LVH and remodelling patterns different from concentric LVH are common in CA. Increased LV mass index, increased RWT, and asymmetric LVH are independently associated with the diagnosis. Traditional diagnostic criteria show poor sensitivity.
Introduction
Cardiac amyloidosis (CA) is definitely diagnosed by the pathological demonstration of extracellular amyloid deposition in the myocardium. However, endomyocardial biopsy (EMB) is not widely available due to its invasive nature. Thus, EMB is frequently omitted in the presence of typical echocardiographic findings and extracardiac histological confirmation of amyloidosis. Although concentric LV hypertrophy (LVH) is commonly seen echocardiografically, it is not specific and may indicate end-stage disease. The presence of low voltage on the ECG has increased specificity, but still lacks sensitivity in early stages.
Recently, the presence of a typical pattern on late gadolinum enhancement (LGE) with cardiac magnetic resonance (CMR) has demonstrated variable sensitivity (69–97%) but particularly high specificity (94%) compared to EMB. Even without contrast, CMR may be an attractive alternative to echocardiography due to its more precise characterisation of tridimensional morphological and geometric changes in different cardiomyopathies. However, there is limited data on LV morphological and remodelling patterns with CMR in CA.
We hypothesise that CMR can characterise these parameters and that they provide diagnostic value for the detection of CA in a contemporary population referred for CMR. We also evaluated the accuracy of 'traditional' diagnostic criteria.
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