Does CMR have an additive role over echo in evaluating ischemic LV dysfunction?

Delayed myocardial enhancement in children with different types of cardiomyopathy: a diagnostic and prognostic tool

Abstract

Background

The pattern of late gadolinium enhancement (LGE) in cardiomyopathy is quite different in children compared to adults. In addition, the data about LGE imaging in children are still restricted, so the goal was to study the role of cardiac magnetic resonance (CMR) with different techniques, including LGE images in diagnosis and evaluation of different types of cardiomyopathy in children.

Results

In group A (enhancement group), LVEDV 146.2 (144) ml, indexed LVEDV 81.8 (195) ml, LVESV 50 (357) ml, indexed LVESV 47.5 (243) ml, and LVEF 36% (64%), and a major adverse effect was found in 12 out of 15 cases (80%). However, in group B (non-enhancement group), the results were LVEDV 72 (303) ml, indexed LVEDV 75 (318) ml, LVESV 30 (220) ml, indexed LVESV 37.1 (189) ml, and LVEF 45.79% (65%), and a major adverse cardiac effect was found in 2 out of 16 cases (12.5%). The LVEF was lower, and LV volume indices including LVEDV and LVESV were higher in patients with LGE compared to those without LGE with a statistically significant difference (p value = 0.001, p value = 0.003, and p value = 0.005, respectively). Furthermore, it was also found that a major adverse effect occurs with higher incidence in enhancement cases (92%) as compared to non-enhancement cases (12.5%) with a statistically significant difference (p value ≤ 0.001). LGE was found in 15 cases out of 31 cases (48.4%); however, the remaining 13 cases had no contrast study.

Conclusion

Cardiac MRI can be considered as an important non-invasive imaging modality, not only for assessment but also for differentiation between ischemic and non-ischemic cardiomyopathy in the pediatric age group. Using its different techniques allows a better assessment of morphologic and functional parameters in cardiomyopathy. Moreover, the late gadolinium enhancement is regarded as a promising non-invasive tool in the detection and quantification of myocardial scars. That is considered of high importance in diagnosis, categorization, and detection of etiology in most cases of different types of cardiomyopathy, in addition to risk stratification that can be an essential step in patient management.

Quantification of Biventricular Strains in Heart Failure With Preserved Ejection Fraction Patient Using Hyperelastic Warping Method

Heart failure (HF) imposes a major global health care burden on society and suffering on the individual. About 50% of HF patients have preserved ejection fraction (HFpEF). More intricate and comprehensive measurement-focused imaging of multiple strain components may aid in the diagnosis and elucidation of this disease. Here, we describe the development of a semi-automated hyperelastic warping method for rapid comprehensive assessment of biventricular circumferential, longitudinal, and radial strains that is physiological meaningful and reproducible. We recruited and performed cardiac magnetic resonance (CMR) imaging on 30 subjects [10 HFpEF, 10 HF with reduced ejection fraction patients (HFrEF) and 10 healthy controls]. In each subject, a three-dimensional heart model including left ventricle (LV), right ventricle (RV), and septum was reconstructed from CMR images. The hyperelastic warping method was used to reference the segmented model with the target images and biventricular circumferential, longitudinal, and radial strain-time curves were obtained. The peak systolic strains are then measured and analyzed in this study. Intra- and inter-observer reproducibility of the biventricular peak systolic strains was excellent with all ICCs > 0.92. LV peak systolic circumferential, longitudinal, and radial strain, respectively, exhibited a progressive decrease in magnitude from healthy control→HFpEF→HFrEF: control (-15.5 ± 1.90, -15.6 ± 2.06, 41.4 ± 12.2%); HFpEF (-9.37 ± 3.23, -11.3 ± 1.76, 22.8 ± 13.1%); HFrEF (-4.75 ± 2.74, -7.55 ± 1.75, 10.8 ± 4.61%). A similar progressive decrease in magnitude was observed for RV peak systolic circumferential, longitudinal and radial strain: control (-9.91 ± 2.25, -14.5 ± 2.63, 26.8 ± 7.16%); HFpEF (-7.38 ± 3.17, -12.0 ± 2.45, 21.5 ± 10.0%); HFrEF (-5.92 ± 3.13, -8.63 ± 2.79, 15.2 ± 6.33%). Furthermore, septum peak systolic circumferential, longitudinal, and radial strain magnitude decreased gradually from healthy control to HFrEF: control (-7.11 ± 1.81, 16.3 ± 3.23, 18.5 ± 8.64%); HFpEF (-6.11 ± 3.98, -13.4 ± 3.02, 12.5 ± 6.38%); HFrEF (-1.42 ± 1.36, -8.99 ± 2.96, 3.35 ± 2.95%). The ROC analysis indicated LV peak systolic circumferential strain to be the most sensitive marker for differentiating HFpEF from healthy controls. Our results suggest that the hyperelastic warping method with the CMR-derived strains may reveal subtle impairment in HF biventricular mechanics, in particular despite a "normal" ventricular ejection fraction in HFpEF.