Novel role of cardiovascular MRI to contextualise tuberculous pericardial inflammation and oedema as predictors of constrictive pericarditis

Tuberculosis (TB) and human immunodeficiency virus/acquired immunodeficiency syndrome have reached epidemic proportions, particularly affecting vulnerable populations in low- and middle-income countries of sub-Saharan Africa. TB pericarditis is the commonest cardiac manifestation of TB and is the leading cause of constrictive pericarditis, a reversible (by surgical pericardiectomy) cause of diastolic heart failure in endemic areas. Unpacking the complex mechanisms underpinning constrictive haemodynamics in TB pericarditis has proven challenging, leaving various basic and clinical research questions unanswered. Subsequently, risk stratification strategies for constrictive outcomes have remained unsatisfactory. Unique pericardial tissue characteristics, as identified on cardiovascular magnetic resonance imaging, enable us to stage and quantify pericardial inflammation and may assist in identifying patients at higher risk of tissue remodelling and pericardial constriction, as well as predict the degree of disease reversibility, tailor medical therapy, and determine the ideal timing for surgical pericardiectomy.

P607Myocardial injury in systemic lupus erythematosus defined by cardiac magnetic resonance imaging: clinical and echocardiographic characteristics

Background

Lupus myocarditis (LM) occurs in 5–10% of patients with systemic lupus erythematosus (SLE). Subclinical myocardial inflammation is detected in 37% at post mortem. Echocardiographic strain analyses (speckle tracking [STE]) supports subclinical myocardial dysfunction in SLE. Tissue characterization by cardiac magnetic resonance (CMR) identifies myocardial inflammation, necrosis/fibrosis, detecting clinical and subclinical myocardial injury (MIN). It is the non-invasive diagnostic modality of choice for myocarditis (all types) based on the Lake Louise criteria (LLC). The utility of CMR is limited by cost (in resource limited settings) as well as intolerance of / contra-indications to CMR.

Purpose

Determine prevalence of MIN in SLE (as per LLC). Compare clinical and echocardiographic features of patients with and without MIN. Identify echocardiographic predictors of MIN.

Methods

A prospective crossectional study was done at Tygerberg Hospital, Western Cape, South Africa. Adult inpatients, fulfilling the 2012 classification criteria for SLE were screened for inclusion. Echocardiography (echo) included strain analyses (segmental and global [GLS]) through STE and regional function assessment (wall motion score (WMS)). Patients were grouped according to CMR evidence of MIN (absent LLC [AC]; single criterion [SC]; fulfilling LLC). Clinical, laboratory and echo parameters were compared between groups. Logistic regression and ROC were used to determine predictors of MIN.

Results

49/106 SLE patients screened were included (Figure 1). The median age was 27 years (IQR: 22–35) and 88% were female. 46.9% of patients had MIN (≥1 criterion): 12.2% fulfilled LLC and 34.7% had a SC. Demographic features, cardiac risk factors (including antiphospholipid syndrome) and renal disease were similar among groups. Compared to the AC group, SLE disease activity was higher in patients fulfilling LLC (p=0.022), but not in the SC group (p=0.813). A clinical and echo diagnosis of LM was made in all patients fulfilling LLC (p<0.001), in 17.6% of patients in the SC group (p=0.026) vs none in the AC group. Anti-DsDNA (p=0.054) and anti-B2GP1 (p=0.081) were more frequently positive in the SC vs AC group. The WMS was higher in LLC and SC groups (p=0.006; p=0.083) with mid and basal strain more impaired in patients with MIN (p=0.043; p=0.047). LVID and mid STE score (number of segments with impaired STE) combined was the best predictor of MIN (OR: 2.1; 95% CI: 1.2–3.5; p=0.008). The predictive model had an AUC of 0.791 (PPV: 81.8%; NPV: 86.4%).

Figure 1

Conclusion

CMR is limited by a high exclusion rate in SLE, mainly due to renal disease. CMR evidence of MIN is common in SLE, even in the absence of clinical myocardial dysfunction or high lupus activity. Impaired echo regional and global function occurs more frequently in patients with MIN. STE combined with LVID predicts the presence of MIN detected by CMR and has potential as a cost effective screening tool.

P3134Variations in anterior mitral valve leaflet restriction that may lead to the erroneous diagnosis of rheumatic heart disease

Introduction

Anterior mitral valve leaflet (AMVL) restriction is a prominent morphological feature of rheumatic heart disease (RHD). The World Heart Federation (WHF) criteria for echocardiographic diagnosis of RHD rely on the use of colloquial terms such as “dog-leg” to define AMVL restriction rather than a strict, reproducible definition. We recognise AMVL restriction when the tip of the leaflet is seen to point away from the interventricular septum and towards the posterior left ventricular (LV) wall at peak diastole in the parasternal long axis (PSLAX) view. This definition however risks inclusion of a finding commonly identified in our high-risk screening program (Echo in Africa- EIA) which demonstrates gradual AMVL bowing (so-called “slow-bow”) from the proximal to mid-leaflet but with free motion ('fluttering') of the tip during diastole. This is in contrast to RHD-related restriction which typically involves the distal AMVL tip only. We propose that the former is a normal variant of the AMVL and is unrelated to the RHD process, provided no concomitant morphological features of RHD are identified.

Purpose

Determine the prevalence of “slow-bow” AMVL restriction between two cohorts of schoolchildren with a documented high-and low-RHD prevalence.

Methods

Retrospective analysis of EIA data obtained from children (aged 13–18) attending two separate South African schools. The high-RHD prevalence school (HR) demonstrated a 0.8% rate of WHF “definite RHD”. The low-RHD prevalence school (LR) demonstrated no cases of WHF “definite RHD”. Cases of AMVL restriction were identified and classified according to the definitions provided above.

Results

A total of 941 screening studies (HR cohort n=577 /LR cohort n=364) were evaluated. 74 cases of AMVL restriction (12.82%, 95%, CI 10.34–15.80) were identified in the HR cohort of which 8 cases demonstrated AMVL-tip restriction (1.39%, 95%, CI 0.70–2.71) and 65 cases demonstrated “slow bow” (11.27%, 95%, CI 8.94–14.11). There were no cases of AMVL-tip restriction observed in the LR-cohort and 35 cases of “slow-bow”(9.62%, 95%, CI 7–13.08).

A. “Slow bow”; B. “Distal tip restriction”.

Conclusion

Our results support the hypothesis that “slow-bow” AMVL restriction is a common variant of the AMVL amongst South African school children and unrelated to the RHD process. Further research is required to investigate the exact mechanism underlying this form of AMVL restriction.

Acknowledgement/Funding

Edwards Lifescience EHM grant

Prominent inter-scallop separations of the posterior leaflet of the mitral valve: an important cause of 'pathological' mitral regurgitation

The 2012 World Heart Federation (WHF) criteria for echocardiographic diagnosis of rheumatic heart disease (RHD) identify that the finding of 'pathological' mitral regurgitation (MR) in a screened individual increases the likelihood of detecting underlying RHD. Cases of isolated "pathological MR are thus identified as 'borderline RHD'. A large-scale echocardiographic screening program (Echo in Africa) in South Africa has identified that inter-scallop separations of the posterior mitral valve leaflet (PMVL) can give rise to 'pathological' MR. The authors propose that this finding when associated with isolated 'pathological' MR is unrelated to the rheumatic disease process. In this case report, we present two examples of 'pathological' MR related to inter-scallop separation from the Echo in Africa image database. We provide additional screening tips to accurately identify this entity.

Screening for rheumatic heart disease: is a paradigm shift required?

This focused review presents a critical appraisal of the World Heart Federation criteria for the echocardiographic diagnosis of rheumatic heart disease (RHD) and its performance in African RHD screening programmes. It identifies various logistical and methodological problems that negatively influence the current guideline’s performance. The authors explore novel RHD screening methodology that could address some of these shortcomings and if proven to be of merit, would require a paradigm shift in the approach to the echocardiographic diagnosis of subclinical RHD.

Clinical features and outcome of lupus myocarditis in the Western Cape, South Africa

BACKGROUND

African American ethnicity is independently associated with lupus myocarditis compared with other ethnic groups. In the mixed racial population of the Western Cape, South Africa, no data exists on the clinical features/outcome of lupus myocarditis.

OBJECTIVES

The objective of this study was to give a comprehensive description of the clinical features and outcome of acute lupus myocarditis in a mixed racial population.

METHODS

Clinical records (between 2008 and 2014) of adult systemic lupus erythematosus (SLE) patients at a tertiary referral centre were retrospectively screened for a clinical and echocardiographic diagnosis of lupus myocarditis. Clinical features, laboratory results, management and outcome were described. Echocardiographic images stored in a digital archive were reanalysed including global and regional left ventricular function. A poor outcome was defined as lupus myocarditis related mortality or final left ventricular ejection fraction (LVEF) <40%.

RESULTS

Twenty-eight of 457 lupus patients (6.1%) met inclusion criteria: 92.9% were female and 89.3% were of mixed racial origin. Fifty-three per cent of patients presented within three months after being diagnosed with SLE. Seventy-five per cent had severely active disease (SLE disease activity index ≥ 12) and 67.9% of patients had concomitant lupus nephritis. Laboratory results included: lymphopenia (69%) and an increased aRNP (61.5%). Treatment included corticosteroids (96%) and cyclophosphamide (75%); 14% of patients required additional immunosuppression including rituximab. Diastolic dysfunction and regional wall motion abnormalities occurred in > 90% of patients. LVEF improved from 35% to 47% (p = 0.023) and wall motion score from 1.88 to 1.5 (p = 0.017) following treatment. Overall mortality was high (12/28): five patients (17.9%) died due to lupus myocarditis (bimodal pattern). Patients who died of lupus myocarditis had a longer duration of SLE (p = 0.045) and a lower absolute lymphocyte count (p = 0.041) at diagnosis. LVEF at diagnosis was lower in patients who died of lupus myocarditis (p = 0.099) and in those with a persistent LVEF < 40% (n = 5; p = 0.046).

CONCLUSIONS

This is the largest reported series on lupus myocarditis. The mixed racial population had a similar prevalence, but higher mortality compared with other ethnic groups (internationally published literature). Patients typically presented with high SLE disease activity and the majority had concomitant lupus nephritis. Lymphopenia and low LVEF at presentation were of prognostic significance, associated with lupus myocarditis related mortality or a persistent LVEF < 40%.