RESUMEN
BACKGROUND: Midwall fibrosis (MWF) detected by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) predicts adverse outcome in adults with dilated cardiomyopathy (DCM). Its relevance in children and adolescents is relatively unknown. Left ventricular (LV) strain, rotation and twist are important parameters of cardiac function; yet, their role in pediatric heart failure is understudied. This study aimed to evaluate MWF and cardiac mechanics in pediatric DCM. METHODS: Patients ≤21 years with primary DCM were prospectively enrolled and underwent standardized CMR including LGE. All participants were categorized according to the presence or absence of MWF (MWF+ vs. MWF-). Cardiac mechanics were assessed using CMR feature tracking. Impaired LV twist with apex and base rotating in the same direction was termed rigid body rotation (RBR). RESULTS: In total, 17 patients (median age 11.2 years) were included. MWF was present in seven patients (41%). Median N-terminal pro brain natriuretic peptide (NT-proBNP) was higher (5,959 vs. 242 pg/ml, p = 0.887) and LV ejection fraction (LVEF) lower (28 vs. 39%, p = 0.536) in MWF+ vs. MWF- patients, yet differences were not statistically significant. MWF+ patients had reduced global longitudinal (GLS), circumferential (GCS) and radial strain (GRS), again without statistical significance (p = 0.713, 0.492 and 1.000, respectively). A relationship between MWF and adverse outcome was not seen (p = 0.637). RBR was more common in MWF+ (67 vs. 50%), and was associated with the occurrence of adverse events (p = 0.041). Patients with RBR more frequently were in higher New York Heart Association classes (p = 0.035), had elevated NT-proBNP levels (p = 0.002) and higher need for catecholamines (p = 0.001). RBR was related to reduced GLS (p = 0.008), GCS (p = 0.031), GRS (p = 0.012), LV twist (p = 0.008), peak apical rotation (p < 0.001), and LVEF (p = 0.001), elevated LV end-diastolic volume (p = 0.023) and LV end-systolic volume (p = 0.003), and lower right ventricular stroke volume (p = 0.023). CONCLUSIONS: MWF was common, but failed to predict heart failure. RBR was associated with clinical and biventricular functional signs of heart failure as well as the occurrence of adverse events. Our findings suggest that RBR may predict outcomes and may serve as a novel marker of disease severity in pediatric DCM.Clinical Trial Registration: https://clinicaltrials.gov/, identifier: NCT03572569.
RESUMEN
BACKGROUND: Patients with newly diagnosed dilated cardiomyopathy (DCM) and advanced heart failure have a very high morbidity and mortality with an unpredictable clinical course. We investigated the role of cardiovascular magnetic resonance (CMR) imaging using late gadolinium enhancement (LGE) in this cohort of high-risk patients. We hypothesized that LGE has high prognostic value in primary DCM patients referred for possible transplantation/left ventricular assist device (LVAD) consideration. METHODS: Over 49 consecutive months, 61 consecutives DCM patients were referred for standard CMR(1.5T, GE) to interrogate the LV pattern, distribution, and extent of LGE (MultiHance, Princeton, NJ). Inclusion criteria for a primary non-ischaemic DCM and EF <45% were met in 31 patients. DCM patients were categorized into: (i) presence of midwall LV stripe (+Stripe) and (ii) absence of midwall stripe (-Stripe) groups. Primary outcome was defined by the composite of death, need for LV assist device (LVAD), and urgent orthotopic cardiac transplantation (Tx) during a 12-month follow-up period. Kaplan-Meier survival analysis was conducted grouping patients by +Stripe and -Stripe. RESULTS: There were no differences between groups for demographics, blood pressure, labs, baseline LVEF, NYHA class, or invasive haemodynamics. There were 18 patients (58%) with +Stripe. Nine events occurred: seven patients required urgent Tx and/or LVAD implantation and two patients died. The +Stripe categorization strongly predicted the need for LVAD, urgent Tx surgery, and death (log-rank = 9, P = 0.002). All the events occurred in the +Stripe patients with no MACE experienced in the -Stripe group. The -Stripe group experienced marked signs of improvement in LVEF (P = 0.01) at follow-up. LVEDD was predictive of need for LVAD/Tx and death by univariate analysis. Otherwise, no common clinical metric such as LVEF, LVEDV, RVEF, RVEDV, or any invasive haemodynamic parameter predicted MACE. CONCLUSIONS: The presence of +Stripe on CMR is strongly predictive of LVAD, transplant need, and death during a 12-month follow-up period in DCM patients in this proof of concept study. All -Stripe patients survived without experiencing any events. Incorporating CMR imaging into routine clinical practice may have prognostic value in DCM patients; indicating conservative management in low-risk patients while expectantly managing high-risk patients.