Diagnostic and prognostic value of quantitative cardiac magnetic resonance imaging biomarkers in systemic lupus erythematosus: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to compare CMR imaging biomarkers between SLE patients and matched controls.

MATERIALS AND METHODS

Electronic databases were systematically searched from inception until November 2023. All studies reporting CMR imaging data in SLE patients were included. PRISMA guidelines were followed, and risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. CMR findings of SLE patients were compared to that of matched controls. Clinical features associated with CMR biomarkers were collected in a qualitative analysis.

RESULTS

A total of 64 studies were included in the systematic review pooling 3304 individuals including 1870 SLE patients. Of these, 19 case-control studies were included in the comparative meta-analysis (1576 individuals, including 884 SLE patients). Compared to controls, left ventricular (LV) ejection fraction (62% vs. 64%, p = 0.001) and indexed end-diastolic volume (77 vs. 72 mL/m2, p = 0.006) were significantly altered in SLE patients. Late gadolinium enhancement (LGE) extent was higher in SLE patients (LGE mass/total LV mass: 3.5% vs. 1.1%, p = 0.009). Native T1 and T2 relaxation times were significantly higher in SLE patients (native T1 [1.5 T]: 1005 vs. 982 ms, p = 0.02; native T1 [3 T]: 1267 vs. 1140 ms, p < 0.001; T2 [all fields]: 58 vs. 51 ms, p < 0.001). Three studies found an association between disease activity and increased T2 relaxation times. Two studies identified an association between clinical outcomes and CMR parameters.

CONCLUSIONS

While CMR-assessed ventricular function and volumes only slightly differed in SLE patients when compared to controls, myocardial tissue characterization parameters were significantly modified and associated with disease activity.

KEY POINTS

Question What are the diagnostic and prognostic values of cardiac magnetic resonance (CMR) quantitative parameters in systemic lupus erythematosus (SLE) patients? Findings Myocardial tissue characterization parameters are significantly altered in SLE patients and associated with disease activity. Clinical relevance CMR imaging demonstrates subclinical cardiac alterations in systemic lupus erythematosus patients. Additional studies are required to further demonstrate the prognostic value of CMR in SLE.

Myocardial fibrosis associates with lupus anticoagulant in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that carries increased risk of cardiovascular disease; however, the underlying pathophysiological mechanisms remain poorly understood. We aimed to investigate the prevalence and degree of myocardial fibrosis in SLE patients and associated disease characteristics. Forty-nine SLE patients (89% female, mean age 52 ± 13 years, median disease duration 19 (11-25) years) and 79 sex-and age-matched healthy controls were included. CMR with T1 mapping was performed on SLE patients and healthy controls. Fifty-one SLE patients received gadolinium contrast for the evaluation of late gadolinium enhancement (LGE) and extra cellular volume (ECV). Multiple linear regression analyses were performed to investigate the association between markers of myocardial fibrosis on CMR (LGE, T1, ECV) and SLE-related variables [clinical disease activity, lupus nephritis, chronic kidney disease, anti-cardiolipin and/or anti-beta-2 glycoprotein I antibodies, and lupus anticoagulant (LAC)] with adjustment for traditional risk factors. T1 values were elevated in SLE patients compared to healthy controls (1031 ± 36 ms vs. 1019 ± 25 ms, p = 0.01). LGE was present in 20% of SLE patients who received gadolinium contrast. On multivariable analysis, LAC was associated with LGE in SLE patients (β = 3.87, p = 0.02). Neither T1 nor ECV associated with SLE disease characteristics; however, there was a trend towards an association between LAC and T1 (β = 16.9, p = 0.08). SLE patients displayed signs of myocardial fibrosis on CMR that were associated with the presence of LAC. These findings support the pathophysiological understanding of LAC as a mediator of microvascular and subsequent myocardial dysfunction.

Cardiovascular magnetic resonance imaging in myocardial involvement of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that primarily affects young women. Myocardial involvement in SLE frequently occurs and it is rather challenging to make the diagnosis in current clinical settings, mainly due to the extensive clinical presentation of signs and symptoms. As a noninvasive imaging reference in diagnosing cardiomyopathy and myocarditis, cardiovascular magnetic resonance (CMR) imaging can provide new insight into myocardial abnormalities including inflammation, fibrosis, and microcirculation. Therefore, the main aim of this work was to systematically review the pathology, clinical features, and diagnosis, while illustrating the clinical role of CMR on myocardial involvement of SLE.

Pathophysiology of LV Remodeling Following STEMI: A Longitudinal Diffusion Tensor CMR Study

BACKGROUND

Adverse LV remodeling post-ST-segment elevation myocardial infarction (STEMI) is associated with a poor prognosis, but the underlying mechanisms are not fully understood. Diffusion tensor (DT)-cardiac magnetic resonance (CMR) allows in vivo characterization of myocardial architecture and provides unique mechanistic insight into pathophysiologic changes following myocardial infarction.

OBJECTIVES

This study evaluated the potential associations between DT-CMR performed soon after STEMI and long-term adverse left ventricular (LV) remodeling following STEMI.

METHODS

A total of 100 patients with STEMI underwent CMR at 5 days and 12 months post-reperfusion. The protocol included DT-CMR for assessing fractional anisotropy (FA), secondary eigenvector angle (E2A) and helix angle (HA), cine imaging for assessing LV volumes, and late gadolinium enhancement for calculating infarct and microvascular obstruction size. Adverse remodeling was defined as a 20% increase in LV end-diastolic volume at 12 months.

RESULTS

A total of 32 patients experienced adverse remodeling at 12 months. Compared with patients without adverse remodeling, they had lower FA (0.23 ± 0.03 vs 0.27 ± 0.04; P < 0.001), lower E2A (37 ± 6° vs 51 ± 7°; P < 0.001), and, on HA maps, a lower proportion of myocytes with right-handed orientation (RHM) (8% ± 5% vs 17% ± 9%; P < 0.001) in their acutely infarcted myocardium. On multivariable logistic regression analysis, infarct FA (odds ratio [OR]: <0.01; P = 0.014) and E2A (OR: 0.77; P = 0.001) were independent predictors of adverse LV remodeling after adjusting for left ventricular ejection fraction (LVEF) and infarct size. There were no significant changes in infarct FA, E2A, or RHM between the 2 scans.

CONCLUSIONS

Extensive cardiomyocyte disorganization (evidenced by low FA), acute loss of sheetlet angularity (evidenced by low E2A), and a greater loss of organization among cardiomyocytes with RHM, corresponding to the subendocardium, can be detected within 5 days post-STEMI. These changes persist post-injury, and low FA and E2A are independently associated with long-term adverse remodeling.

Characterization and clinical significance of biventricular mechanics in patients with systemic lupus erythematosus by 3T cardiovascular magnetic resonance tissue tracking

BACKGROUND

Detecting impaired left ventricle (LV) or right ventricle (RV) mechanics could aid in fully understanding the process of cardiac involvement in patients with systemic lupus erythematosus (SLE). This study aimed to evaluate biventricular strain parameters derived from cardiac magnetic resonance (CMR) tissue tracking in SLE patients and their association with other clinical variables.

METHODS

A group of 47 SLE patients and 27 healthy controls were enrolled and underwent CMR examination, including cine and late gadolinium enhancement (LGE) imaging. Aside from RV strain parameters in the radial direction, biventricular global peak strain and peak systolic/diastolic global strain rate in radial, circumferential, and longitudinal directions were assessed for each participant. Multivariate linear regression analysis was used to analyze the factors related to the biventricular strain parameters. Receiver operating characteristic (ROC) analysis was used to identify RV dysfunction.

RESULTS

Compared with the controls, part of the biventricular strain parameters in the SLE subgroup with preserved ejection fraction (EF) were impaired, which was more significant in the SLE subgroup with reduced EF (all P<0.05). The SLE patients with RV dysfunction (15/47) included patients with LV dysfunction (8/47). The RVEF was associated with impaired LV global peak strain and peak diastolic strain rate in the SLE patients (absolute value of β=0.406-0.715, all P<0.05). The LV LGE in SLE patients (12/47) was associated with LV global longitudinal peak strain and peak diastolic global longitudinal strain rate (β=0.378 and -0.342; all P<0.05). There were independent correlations between pulmonary arterial hypertension and RV global longitudinal peak strain, anti-ribonucleoprotein (RNP) antibody and RV global circumferential peak strain, and pericardial effusion and RV peak diastolic global circumferential strain rate, respectively (β=0.319, 0.359, and -0.285, respectively; all P<0.05). The LV global longitudinal peak strain had greater diagnostic accuracy for RV dysfunction RV dysfunction [area under curve (AUC): 0.933, cut-off value: -13.38%).

CONCLUSIONS

Biventricular strain parameters derived from CMR are sensitive markers of subclinical ventricular function impairment before EF reduction at an early stage of SLE. Biventricular strain analysis could be considered for inclusion in early cardiac functional assessment in SLE patients, particularly LV global longitudinal peak strain, which might assist in therapeutic decision-making and disease monitoring.

Diffusion-weighted imaging in hypertrophic cardiomyopathy: association with high T2-weighted signal intensity in addition to late gadolinium enhancement

Diffusion-weighted imaging (DWI) has been confirmed to be associated with late gadolinium enhancement (LGE) in hypertrophic cardiomyopathy (HCM). In this context, we aimed to study whether DWI could reflect the active tissue injury and edema information of HCM which were usually indicated by T2 weighted images. Forty HCM patients were examined using a 3.0 T magnetic resonance scanner. Cine, T2-weighted short tau inversion recovery (T2-STIR), DWI and LGE sequences were acquired. T1 mapping was also included to quantify the focal and diffuse fibrosis. Cardiac troponin I (cTnI) was tested to assess the recently myocardial injury. Student's t-test, Mann-Whitney U test, One-way analysis, Kruskal-Wallis analysis, the Spearman correlation analysis, and multivariable regression were used in this study. The apparent diffusion coefficient (ADC) was significantly elevated in the cTnI positive group (P = 0.01) and correlated with LGE (ρ = 0.312, P = 0.049) and HighT2 extent (ρ = 0.443, P = 0.004) in the global level. In the segmental analysis, the ADC significantly differentiated the segments with and without HighT2/LGE presence (P = 0.00). The average ADC values were higher in segments with HighT2 and LGE coexistence than in those with only LGE presence (P < 0.05). Multivariable regression indicated that segmental HighT2 and LGE were both contributing factors to the ADC values. In this study of HCM, we confirmed that ADC as a molecular diffusion parameter reflects the replacement fibrosis of myocardium. Moreover, it also reveals edema extent and its association with serum cTnI.

Novel insights into in-vivo diffusion tensor cardiovascular magnetic resonance using computational modeling and a histology-based virtual microstructure

Purpose

To develop histology‐informed simulations of diffusion tensor cardiovascular magnetic resonance (DT‐CMR) for typical in‐vivo pulse sequences and determine their sensitivity to changes in extra‐cellular space (ECS) and other microstructural parameters.

Methods

We synthesised the DT‐CMR signal from Monte Carlo random walk simulations. The virtual tissue was based on porcine histology. The cells were thickened and then shrunk to modify ECS. We also created idealised geometries using cuboids in regular arrangement, matching the extra‐cellular volume fraction (ECV) of 16–40%. The simulated voxel size was 2.8 × 2.8 × 8.0 mm³ for pulse sequences covering short and long diffusion times: Stejskal–Tanner pulsed‐gradient spin echo, second‐order motion‐compensated spin echo, and stimulated echo acquisition mode (STEAM), with clinically available gradient strengths.

Results

The primary diffusion tensor eigenvalue increases linearly with ECV at a similar rate for all simulated geometries. Mean diffusivity (MD) varies linearly, too, but is higher for the substrates with more uniformly distributed ECS. Fractional anisotropy (FA) for the histology‐based geometry is higher than the idealised geometry with low sensitivity to ECV, except for the long mixing time of the STEAM sequence. Varying the intra‐cellular diffusivity (D_IC) results in large changes of MD and FA. Varying extra‐cellular diffusivity or using stronger gradients has minor effects on FA. Uncertainties of the primary eigenvector orientation are reduced using STEAM.

Conclusions

We found that the distribution of ECS has a measurable impact on DT‐CMR parameters. The observed sensitivity of MD and FA to ECV and D_IC has potentially interesting applications for interpreting in‐vivo DT‐CMR parameters.