Lupus myocarditis: review of current diagnostic modalities and their application in clinical practice.

Lupus myocarditis (LM) is a potentially fatal manifestation of SLE, occurring in 5-10% of patients. Clinical manifestations may vary from an unexplained tachycardia to fulminant congestive cardiac failure (CCF). With no single clinical or imaging modality being diagnostic, a rational and practical approach to the patient presenting with possible LM is essential. Markers of myocyte injury (including troponin I and creatine kinase) may be unelevated and do not exclude a diagnosis of LM. Findings on ECG are non-specific but remain essential to exclude other causes of CCF such as an acute coronary syndrome or conduction disorders. Echocardiographic modalities including wall motion abnormalities and speckle tracking echocardiography may demonstrate regional and/or global left ventricular dysfunction and is more sensitive than conventional echocardiography, especially early in the course of LM. Cardiac magnetic resonance imaging (CMRI) is regarded as the non-invasive diagnostic modality of choice in myocarditis. While more sensitive and specific than echocardiography, CMRI has certain limitations in the context of SLE, including technical challenges in acutely unwell and uncooperative patients, contraindications to gadolinium use in the context of renal impairment (including lupus nephritis) and limited literature regarding the application of recommended diagnostic CMRI criteria in SLE. Both echocardiography as well as CMRI may detect subclinical myocardial dysfunction and/or injury of which the clinical significance remains uncertain. Considering these challenges, a combined decision-making approach by rheumatologists and cardiologists interpreting diagnostic test results within the clinical context of the patient is essential to ensure an accurate, early diagnosis of LM.

Outcome of clinical and subclinical myocardial injury in systemic lupus erythematosus - A prospective cohort study.

OBJECTIVES: To determine the outcome of subclinical lupus myocarditis (LM) over twelve months with regards to: mortality; incidence of clinical LM and change in imaging parameters (echocardiography and cardiac magnetic resonance [CMR]). To evaluate the impact of immunosuppression on CMR evidence of myocardial tissue injury. METHODS: SLE patients with and without CMR evidence of myocardial injury (as per 2009 Lake Louise criteria [LLC]) were included. Analysis at baseline and follow-up included: clinical evaluation, laboratory and imaging analyses (echocardiography and CMR). Clinical LM was defined as clinical features of LM supported by echocardiographic and/or biochemical evidence of myocardial dysfunction. Subclinical LM was defined as CMR myocardial injury without clinical LM. RESULTS: Forty-nine SLE patients were included with follow-up analyses (after 12 months) available in 36 patients. Twenty-five patients (51%) received intensified immunosuppressive therapy during follow-up for indications related to SLE. Disease activity (SLEDAI-2K) improved (p < 0.001) from 13 (median;IQR:9-20) to 7 (3-11). One patient without initial CMR evidence of myocardial injury developed clinical LM. Mortality (n = 10) and SLE clinical features were similar between patients with and without initial CMR myocardial injury. Echocardiographic left ventricular ejection fraction (LVEF) (p = 0.014), right ventricular function (p = 0.001) and wall motion abnormalities (p = 0.056) improved significantly but not strain analyses nor the left LV internal diameter index. CMR mass index (p = 0.011) and LVEF (p < 0.001) improved with follow-up but not parameters identifying myocardial tissue injury (LLC). A trend towards a reduction in the presence of CMR criteria was counterbalanced by persistence (n = 7) /development of new criteria (n = 11) in patients. Change in CMR mass index correlated with change in T2-weighted signal (myocardial oedema) (r = 386;p = 0.024). Intensified immunosuppressive therapy had no significant effect on CMR parameters. CONCLUSION: CMR evidence of subclinical LM persisted despite improved SLEDAI-2K, serological markers, cardiac function and CMR mass index. Subclinical LM did not progress to clinical LM and had no significant prognostic implications over 12 months. Immunosuppressive therapy did not have any significant effect on the presence of CMR evidence of myocardial tissue injury. Improvement in CMR mass index correlated with reduction in myocardial oedema and may be used to monitor SLE myocardial injury.

Serum cytokine levels associated with myocardial injury in systemic lupus erythematosus.

OBJECTIVES: To identify cytokines, markers of endothelial activation [soluble vascular cell adhesion molecule-1 (sVCAM-1)] and myocyte strain [soluble ST2 (sST2)] associated with myocardial injury (MInj) in SLE, classified by cardiac magnetic resonance (CMR) criteria. METHODS: CMR was performed on patients with SLE, identifying stages of MInj (inflammation and necrosis or fibrosis). Data captured included: clinical assessment, laboratory and serological analyses, cytokine (IL-1ß, IL-1Ra, IL-2, IL-6, IL-10, IL-17, IL-18, TNF-alpha), sVCAM-1 and sST2 levels. Cytokines were compared with regard to SLE features and evidence of CMR MInj. Predictors of CMR MInj were determined through regression analyses. RESULTS: Forty-one patients with high disease activity (SLEDAI-2K: 13; IQR: 3-17) were included. SLE features included: LN (n = 12), neurolupus (n = 6) and clinical lupus myocarditis (LM) (n = 6). Nineteen patients had CMR evidence of MInj. Patients with a SLEDAI-2K ≥ 12 had higher sVCAM-1 (P = 0.010) and sST2 (P = 0.032) levels. Neurolupus was associated with higher IL-1Ra (P = 0.038) and LN with lower IL-1Ra (P = 0.025) and sVCAM-1 (P = 0.036) levels. Higher IL-1Ra (P = 0.012), IL-17 (P = 0.045), IL-18 (P = 0.003), and sVCAM-1 (P = 0.062) levels were observed in patients with CMR MInj compared with those without. On multivariable logistic regression, IL-1Ra predicted CMR inflammation and fibrosis/necrosis (P < 0.005) while anti-Ro/SSA [odds ratio (OR): 1.197; P = 0.035] and the SLE damage index (OR: 4.064; P = 0.011) predicted fibrosis/necrosis. CONCLUSION: This is a novel description of associations between cytokines and SLE MInj. IL-18 and IL-1Ra were significantly higher in patients with MInj. IL-1Ra independently predicted different stages of CMR MInj. Exploration of the role of these cytokines in the pathogenesis of SLE MInj may promote targeted therapies for LM.

Myocardial injury in systemic lupus erythematosus according to cardiac magnetic resonance tissue characterization: clinical and echocardiographic features.

OBJECTIVES: To determine the prevalence of myocardial injury (MInj) in systemic lupus erythematosus (SLE) according to cardiac magnetic resonance (CMR) criteria. To compare clinical and echocardiographic features of patients with and without MInj and identify predictors of myocardial tissue characteristics according to CMR. METHODS: SLE inpatients underwent CMR screening for MInj based on the Lake Louise Criteria (LLC). Tissue characteristics included inflammation (increased T2-weighted signal or early gadolinium enhancement ratio (EGEr)) and necrosis or fibrosis (late gadolinium enhancement (LGE)). Echocardiographic parameters included left (left ventricular ejection fraction (LVEF)) and right ventricular function (tricuspid annular plane systolic excursion (TAPSE)), global longitudinal strain (GLS), wall motion score (WMSi) and left ventricular internal diameter index (LVIDi). Variables were compared with regards to the presence/absence of CMR criteria. Logistic regression identified variables predictive of CMR tissue characteristics. RESULTS: A hundred and six SLE patients were screened of whom 49 patients were included. Fifty-seven patients were excluded due to intolerance of or contraindication to CMR (27/57 due to renal impairment). Twenty-three patients had CMR evidence of MInj, of which 60.9% was subclinical. Inflammation occurred in 16/23 and necrosis/fibrosis in 12/23 patients. Patients with any evidence of MInj were more frequently anti-dsDNA positive (p = 0.026) and patients fulfilling LLC for myocarditis had higher SLE disease activity (p = 0.022). The LVIDi (p = 0.005), LVEF (p = 0.005) and TAPSE (p = 0.011) were more abnormal in patients with an increased EGEr, whereas WMSi (p = 0.002) and GLS (0.020) were more impaired in patients with LGE. On multivariable logistic regression analyses, TAPSE predicted inflammation (OR: 0.045, p = 0.006, CI: 0.005-0.415) and GLS predicted necrosis/fibrosis (OR: 1.329, p = 0.031, CI: 1.026-1.722). A model including lymphocyte count, TAPSE and LVIDi predicted an increased EGEr on CMR (receiver operating characteristic-curve analyses: area under the curve: 0.901, p < 0.001, sensitivity: 88.9%, specificity: 76.3%). CONCLUSIONS: CMR evidence of MInj frequently occurs in SLE and is often subclinical. The utility of CMR in SLE is limited by a high exclusion rate, mainly due to renal involvement. Models including echocardiographic parameters (TAPSE, LVIDi and GLS) are predictive of CMR myocardial injury. Echocardiography can be used as a cost-effective screening tool with a high negative predictive value, in particular when CMR is contraindicated or unavailable.

Speckle tracking echocardiography in acute lupus myocarditis: comparison to conventional echocardiography.

AIMS: Lupus myocarditis occurs in 5-10% of patients with systemic lupus erythematosus (SLE). No single feature is diagnostic of lupus myocarditis. Speckle tracking echocardiography (STE) can detect subclinical left ventricular dysfunction in SLE patients, with limited research on its utility in clinical lupus myocarditis. We report on STE in comparison to conventional echocardiography in patients with clinical lupus myocarditis. METHODS AND RESULTS: A retrospective study was done at a tertiary referral hospital in South Africa. SLE patients with lupus myocarditis were included and compared to healthy controls. Echocardiographic images were reanalyzed, including global longitudinal strain through STE. A poor echocardiographic outcome was defined as final left ventricular ejection fraction (LVEF) <40%. 28 SLE patients fulfilled the criteria. Global longitudinal strain correlated with global (LVEF: r = -0.808; P = 0.001) and regional (wall motion score: r = 0.715; P < 0.001) function. In patients presenting with a LVEF ≥50%, global longitudinal strain (P = 0.023), wall motion score (P = 0.005) and diastolic function (P = 0.004) were significantly impaired vs controls. Following treatment, LVEF (35-47% (P = 0.023)) and wall motion score (1.88-1.5 (P = 0.017)) improved but not global longitudinal strain. Initial LVEF (34%; P = 0.046) and global longitudinal strain (-9.5%; P = 0.095) were lower in patients with a final LVEF <40%. CONCLUSIONS: This is the first known report on STE in a series of patients with clinical lupus myocarditis. Global longitudinal strain correlated with regional and global left ventricular function. Global longitudinal strain, wall motion score and diastolic parameters may be more sensitive markers of lupus myocarditis in patients presenting with a preserved LVEF ≥50%. A poor initial LVEF and global longitudinal strain were associated with a persistent LVEF <40%. Echocardiography is a non-invasive tool with diagnostic and prognostic value in lupus myocarditis.