Distinctive clinical traits of lupus-related myocarditis: a multicentre retrospective study

Abstract

Objectives: Cardiovascular involvement in systemic lupus erythematosus (SLE) is frequent, but little is known about possible distinctive traits of SLE-related myocarditis (myoSLE) in comparison with patients with SLE (onlySLE) or myocarditis alone (onlyMyo).

Methods: A retrospective analysis was performed comparing patients with myoSLE (n = 25) from three centres with consecutive patients with onlySLE (n = 279) and onlyMyo (n = 88). SLE patients were dichotomized by disease duration ≤1 vs >1 year into recent onlySLE/early myoSLE vs longstanding onlySLE/late myoSLE. Further stratification into disease duration of 1-5, 5-10 and >10 years was also performed. SLE disease activity index 2000 (SLEDAI-2K) was used to estimate disease activity. Myocarditis was diagnosed through biopsy or MRI.

Results: Women were significantly more frequent among myoSLE than among onlyMyo (72% vs 43%; P = 0.013). Compared with onlyMyo, myoSLE patients had a higher frequency of conduction abnormalities (22% vs 5%; P = 0.046) and presented with numerically higher frequencies of left ventricular function compromise (48% vs 30%), along with higher pro-brain natriuretic peptide levels. Inflammation markers were higher in myoSLE compared with onlyMyo and with patients with onlySLE with >10 years of disease duration. SLEDAI-2K was significantly higher in late myoSLE than in longstanding onlySLE. Antiphospholipid syndrome was more frequent in myoSLE than in onlySLE. Multivariate analysis showed an association among myoSLE, anti-β-2-glycoprotein I antibodies (aB2GPI, P = 0.014) and a higher number of involved British Isles Lupus Assessment Group domains in patient history (P = 0.003).

Conclusion: myoSLE has unique clinical traits compared with other forms of myocarditis and is associated with aB2GPI and a more severe SLE course.

Keywords: antiphospholipid antibodies; damage; long-term outcomes; myocarditis; systemic lupus erythematosus.

Figure 1.

Association between aB2GPI and development of myocarditis in SLE. Kaplan–Meyer survival curves showing the risk of developing myocarditis in patients with SLE stratified by their anti-β-2-glycoprotein I (aB2GPI) profile. In this analysis, patients with myoSLE were pooled with patients with onlySLE. Patients with SLE were dichotomized into patients with positive vs negative aB2GPI (aB2GPI⁺, aB2GPI⁻, respectively) and myocarditis was set as the failure event. HR: hazard ratio

Figure 2.

SLE features by disease duration groups. In this figure, patients with myoSLE (green–blue fade, first elements of each couple of data) and onlySLE (orange–light orange fade, second elements of each couple of data) are stratified by disease duration. (A–F) Boxplots showing the distribution of quantitative variables among groups. These variables include the SLE disease activity index 2000 version (SLEDAI-2K), the SLE International Collaborating Clinics/American College of Rheumatology damage index (SDI) along with ESR, CRP, complement C3 and C4 levels at time of assessment. (G) Bar chart showing the prevalence of positive ADNA at time of assessment. Patients with early manifestations (first couples of boxes and whiskers or bars) include patients with SLE duration within 1 year. The parameters of patients with late manifestations (late myoSLE or longstanding SLE) are represented by the second couples of boxes and whiskers or bars and are further subdivided into three classes corresponding to the following couples of boxes and whiskers. *P < 0.05, **P < 0.01. ADNA: anti-DNA; myoSLE: SLE-related myocarditis; onlyMyo: myocarditis alone