Cardiac magnetic resonance parametric mapping can detect early cardiac involvement of patients with systemic sclerosis

Background Systemic sclerosis (SSc) is divided into two subtypes, diffuse and limited cutaneous SSc (dcSSc and lcSSc). The dcSSc subtype has more severe internal organ fibrosis than lcSSc. It is unclear whether cardiovascular magnetic resonance (CMR) parametric mapping can detect early cardiac involvement in these two subtypes. Purpose To detect cardiac involvement and evaluate differences between the two subtypes, we examined CMR parametric mapping. Methods 57 consecutive SSc patients (27 dcSSc and 30 lcSSc) who visited our hospital from July 2018 to February 2021 and underwent CMR at 3.0T (Philips) were included. We analyzed myocardial damage using CMR parametric mapping and compared it with clinical data. Results Mean disease durations of dcSSc and lcSSc were 4.0±6.5 years and 4.4±8.3 years, respectively. Although there were no significant differences in LVEF (56.8±8.8 vs 59.6±7.2), the left and right atrial volume index were significantly larger in dcSSc compared with lcSSc (all p<0.05). Focal fibrosis as evaluated by late gadolinium enhancement was found in 9 SSc patients (15.7%) and 4 patients had pulmonary hypertension. DcSSc patients had significantly higher mid-ventricular native T1 (1350.8±73.2 vs 1312.9±52.1, p=0.029) and postcontrast T1 values (640.4±59.4 vs 604.6±42.5, p=0.015) as compared to lcSSc, although there were no significant differences in ECV and T2 values. Native T1 values in mid-ventricular septum were positively correlated with E/e' ratio of echocardiography in overall SSc patients and dcSSc patients but not in lcSSc patients (r=0.320, p=0.021; r=0.505, p=0.010; r=0.195, p=0.329). Native T1 values in mid-ventricular septum were also positively correlated with plasma levels of brain natriuretic peptide (BNP) in overall SSc patients and dcSSc patients but not in lcSSc patients (r=0.353, p=0.008; r=0.484, p=0.011; r=0.113, p=0.559).The multiple regression analysis considering age and sex revealed that mid-ventricular septum native T1 was the independent predictor of E/e' in SSc patients (β=0.306, p=0.026), and dcSSc patients (β=0.553, p=0.007) but not in lcSSc patients (β=−0.282, p=0.105). The ROC curve for predicting E/e'≥14, cut-off value of native T1 in mid-ventricular septum was ≥1348.5msec (AUC 0.762; 95% CI 0.571–0.953; sensitivity 80.0%; specificity 68.1%). BNP was significantly higher in patients with native T1≥1348.5 msec compared with native T1<1348.5 (102.8±112.8 vs 45.7±55.7; p=0.014). The interobserver variability of CMR parametric mapping values was excellent in this study. Conclusion DcSSc patients showed higher native T1 and larger left and right atrial volume index of CMR than lcSSc patients, suggesting that DcSSc patients had more severe myocardial involvement and left ventricular diastolic dysfunction than lcSSc patients. Early detection of the high native T1 may predict the occurrence of cardiovascular events in the future. FUNDunding Acknowledgement Type of funding sources: None. Correlation between native T1 and BNP Correlation between native T1 and E/e'

ANALYSIS OF ECHOCARDIOGRAPHIC AND MRI ANATOMICAL CHARACTERISTICS AND HEMODYNAMIC CHARACTERISTICS OF LEFT VENTRICULAR OUTFLOW TRACT STENOSIS

Objective: To analyze the anatomical morphological and hemodynamic characteristics of left ventricular outflow tract stenosis (LVOTS) by echocardiography and MRI. Methods: The Echocardiography data of 112 patients with LVOTS were retrospectively analyzed by measuring the basal interventricular septal thickness (IVST-b), the left ventricle posterior wall thickness (LVPWT), and the peak pressure gradient of LVOTS, as well as by observing the characteristics of spectral pattern and the presence of systolic anterior motion of mitral valve leaflets. A Siemens 3.0T MRI scanner was used to scan the contrast-enhanced left ventricular (LV) volume of all cases. The obtained end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) of LV were compared with the Echocardiography results. Results: The 112 patients were divided into four groups: hypertrophic obstructive cardiomyopathy (Group I, 42 cases), hypertensive left ventricular hypertrophy (Group II, 40 cases), basal septal hypertrophy in the elderly (Group III, 21 cases), and the subaortic membrane (Group IV, 9 cases). The continuous wave (CW) Doppler characteristic of Groups I, II, and III was broadsword-shaped jet, and that of Group IV was equilateral triangle-like spectrum. The IVST-b, IVST-b/LVPWT ratio and peak pressure gradient of LVOTS of Group I was significantly higher than those in Groups II and III ([Formula: see text]). The LVPWT of the first three groups was slightly correlated with the LVOTS peak pressure gradient ([Formula: see text], respectively, [Formula: see text]). There were no statistically significant differences between Echocardiography and MRI results regarding the LV EDV, ESV, SV, and EF ([Formula: see text]), and no statistically significant differences were found between Echocardiography and MRI results regarding the myocardial thicknesses of septal, anterior, lateral, and inferior walls ([Formula: see text]). The Pearson’s correlation analysis demonstrated correlations between MRI and Echocardiography results for LV EDV, ESV, SV, and EF ([Formula: see text], 0.002, 0.009, and [Formula: see text], respectively). The MRI enhancement was shown as delayed enhancement in 52 cases, localized enhancement in 8 cases, diffuse enhancement in 6 cases, and transmural enhancement in 3 cases, with abnormal enhancement lesions distributed in the area of ventricular septum free wall junctions and ventricular septum. Conclusion: Using MRI to evaluate LV function of hypertrophic cardiomyopathy is reliable and accurate. MRI enhancement can be used for the quantitative measurement of myocardial fibrosis. Echocardiography can distinguish the stenosis types of LVOTS. The IVST-b and existence of SAM may be important anatomical characteristics determining the degree of dynamic stenosis, and MRI combined with Echocardiography can provide important detailed information.