Cardiovascular Magnetic Resonance in the Management of Cardiac Amyloidosis: Current and Future Clinical Applications.

Cardiac magnetic resonance represents the gold standard imaging technique to assess cardiac volumes, wall thickness, mass, and systolic function but also to provide noninvasive myocardial tissue characterization across almost all cardiac diseases. In patients with cardiac amyloidosis, increased wall thickness of all heart chambers, a mildly reduced ejection fraction and occasionally pleural and pericardial effusion are the characteristic morphologic anomalies. The typical pattern after contrast injection is represented by diffuse areas of late gadolinium enhancement, which can be focal and patchy in very early stages, circumferential, and subendocardial in intermediate stages or even diffuse transmural in more advanced stages.

Magnetic Resonance Imaging Characterization and Clinical Outcomes of Dilated and Arrhythmogenic Left Ventricular Cardiomyopathies.

BACKGROUND: Nondilated left ventricular cardiomyopathy (NDLVC) has been recently differentiated from dilated cardiomyopathy (DCM). A comprehensive characterization of these 2 entities using cardiac magnetic resonance (CMR) and genetic testing has never been performed. OBJECTIVES: This study sought to provide a thorough characterization and assess clinical outcomes in a large multicenter cohort of patients with DCM and NDLVC. METHODS: A total of 462 patients with DCM (227) or NDLVC (235) with CMR data from 4 different referral centers were retrospectively analyzed. The study endpoint was a composite of sudden cardiac death or major ventricular arrhythmias. RESULTS: In comparison to DCM, NDLVC had a higher prevalence of pathogenic or likely pathogenic variants of arrhythmogenic genes (40% vs 23%; P < 0.001), higher left ventricular (LV) systolic function (LV ejection fraction: 51% ± 12% vs 36% ± 15%; P < 0.001) and higher prevalence of free-wall late gadolinium enhancement (LGE) (27% vs 14%; P < 0.001). Conversely, DCM showed higher prevalence of pathogenic or likely pathogenic variants of nonarrhythmogenic genes (23% vs 12%; P = 0.002) and septal LGE (45% vs 32%; P = 0.004). Over a median follow-up of 81 months (Q1-Q3: 40-132 months), the study outcome occurred in 98 (21%) patients. LGE with septal location (HR: 1.929; 95% CI: 1.033-3.601; P = 0.039) was independently associated with the risk of sudden cardiac death or major ventricular arrhythmias together with LV dilatation, older age, advanced NYHA functional class, frequent ventricular ectopic activity, and nonsustained ventricular tachycardia. CONCLUSIONS: In a multicenter cohort of patients with DCM and NDLVC, septal LGE together with LV dilatation, age, advanced disease, and frequent and repetitive ventricular arrhythmias were powerful predictors of major arrhythmic events.

Biventricular Tissue Tracking with Cardiovascular Magnetic Resonance: Reference Values of Left- and Right-Ventricular Strain.

We derived reference values of left-ventricular (LV) and right-ventricular (RV) strain parameters in a cohort of 100 healthy subjects by feature tracking cardiac magnetic resonance (FT-CMR). Global and regional strain values were calculated for the LV; circumferential and radialSAX strain parameters were derived from the short-axis (SAX) stack, while longitudinal and radialLAX strain parameters were assessed in three long-axis (LAX) views. Only global longitudinal strain (GLS) was calculated for the RV. Peak global LV circumferential strain was -16.7% ± 2.1%, LV radialSAX strain was 26.4% ± 5.1%, LV radialLAX strain was 31.1% ± 5.2%, LV GLS was -17.7% ± 1.9%, and RV GLS was -23.9% ± 4.1%. Women presented higher global LV and RV strain values than men; all strain values presented a weak relationship with body surface area, while there was no association with age or heart rate. A significant association was detected between all LV global strain measures and LV ejection fraction, while RV GLS was correlated to RV end-diastolic volume. The intra- and inter-operator reproducibility was good for all global strain measures. In the regional analysis, circumferential and radial strain values resulted higher at the apical level, while longitudinal strain values were higher at the basal level. The assessment of cardiac deformation by FT-CMR is feasible and reproducible and gender-specific reference values should be used.

Prevalence and prognostic impact of nonischemic late gadolinium enhancement in stress cardiac magnetic resonance.

AIM: To assess the prevalence and prognostic significance of NI-LGE in patients undergoing stress-CMR. METHODS: Stress-CMR with either dipyridamole or adenosine was performed in 283 patients (228 men, 81%) including perfusion imaging, wall motion evaluation and LGE. Follow-up was completed in all enrolled patients (median time: 1850 days; interquartile range: 1225-2705 days). Composite endpoint included cardiac death, ventricular tachycardia, myocardial infarction, stroke, hospitalization for cardiac cause and coronary revascularization performed beyond 90 days from stress-CMR scans. RESULTS: One hundred and twelve patients (40%) had negative LGE (no-LGE), 140 patients (49%) I-LGE and 31 patients (11%) NI-LGE. Twenty-five events occurred in the no-LGE group, 68 in I-LGE and 11 in the NI-LGE group. On survival curves, patients with NI-LGE had worse prognosis than patients with no-LGE regardless of the presence of inducible perfusion defects. No significant prognostic differences were found between I-LGE and NI-LGE. CONCLUSION: NI-LGE can be detected in 11% of patients during stress-CMR providing a diagnosis of nonischemic cardiac disease. Patients with NI-LGE have worse prognosis than those with no-LGE.