Diagnostic value of cardiovascular magnetic resonance in acute peripartum cardiomyopathy (PPCM)

Introduction

Peripartum cardiomyopathy (PPCM) is characterised by left ventricular (LV) dilatation and systolic dysfunction developing towards the end of pregnancy or in the first five months postpartum. Cardiovascular magnetic resonance (CMR) allows for comprehensive evaluation of myocardial structure, function, and tissue characteristics. There is a dearth of studies investigating utility of CMR in PPCM.

Purpose

To evaluate diagnostic benefit of multiparametric assessment of myocardial oedema, fibrotic burden, and strain impairment in PPCM using CMR.

Methods

Eighteen consenting women with newly diagnosed PPCM and 20 female, age-matched healthy controls (HCs) underwent CMR imaging on a 3T MR scanner. A comprehensive, contrast-enhanced CMR protocol was used including cines, native T1 and T2 mapping, myocardial strain analysis, and extracellular volume (ECV). Images were evaluated qualitatively and semi-quantitively for the presence of late gadolinium enhancement (LGE)

Results

Patients with PPCM (median age of 34.5 years [IQR 25–38]) presented with severely impaired LV ejection fraction (LVEF) of 31.4% (IQR 19.6–37.9) and reduced right ventricular (RV) ejection fraction (RVEF) of 37.2% (IQR 21.6–51.7). Global longitudinal strain (GLS) was significantly reduced in PPCM patients (−8.9% [IQR −10.8 to −5.6] vs. −19.7 [−21.9 to −16.3], p<0.001) compared to HCs. LGE was present in 13 (81.2%) PPCM patients and included linear or circumferential mid-wall, patchy and diffuse patterns (LGE mass 19.1g [IQR 15.0–26.5] vs. 11.4g [8.8–13.2] in HCs, p<0.001). Patients with PPCM had significantly higher T1 times (1369.3ms [IQR 1343.7–1409.7 vs. 1207.8ms [IQR 1194.8–1241.3], p<0.001) and ECV (36.5% [32.7–37.0] vs. 27.5 [26.3–28.5], p<0.001) compared to HCs. ECV, native T1 and T2 times did not differ between PPCM patients presenting with LVEF ≤35% and >35%. RV dysfunction (present in 61.1% of PPCM cohort) was associated with significantly higher ECV (37.0% [IQR 36.5–38.4] vs 33.4% [IQR 28.5–37.0], p=0.05 and higher T1 (1409.0ms [IQR 1349.0–1443.0] vs. 1311.3ms [IQR 1299.3–1369.3], p=0.015) compared to those with preserved RV function. LV fibrosis was not significantly different between PPCM patients with and without RV dysfunction. LGE mass correlated negatively with LVEF and RVEF (r=−0.540, p=0.001; r=−0.568, p<0.001), respectively. There was a strong positive correlation between LGE mass and native T1 (r=0.619, p<0.001), LGE mass and GLS (r=0.638, p<0.001) and moderate correlation with ECV (r=0.528, p=0.001) (Figure 1). Small, sub-centimetre pericardial effusions were noted in 83.3% of PPCM patients vs. 10% in HCs (p<0.001).

Conclusion

For the first time, we report a high prevalence of myocardial fibrosis in well-phenotyped patients with newly diagnosed PPCM. Increased LGE mass was associated with severe impairments in LV strain, LVEF and RVEF. RV dysfunction was associated with significantly higher ECV and native T1 times.

Funding Acknowledgement

Type of funding sources: None.

Rationale and design of the African Cardiomyopathy and Myocarditis Registry Program: The IMHOTEP study

BACKGROUND

Heart failure (HF), the dominant form of cardiovascular disease in Africans, is mainly due to hypertension, rheumatic heart disease and cardiomyopathy. Cardiomyopathies pose a great challenge because of poor prognosis and high prevalence in low- and middle-income countries (LMICs). Little is known about the etiology and outcome of cardiomyopathy in Africa. Specifically, the role of myocarditis and the genetic causes of cardiomyopathy are largely unidentified in Africans.

METHOD

The African Cardiomyopathy and Myocarditis Registry Program (the IMHOTEP study) is a pan-African multi-centre, hospital-based cohort study, designed with the primary aim of describing the clinical characteristics, genetic causes, prevalence, management and outcome of cardiomyopathy and myocarditis in children and adults. The secondary aim is to identify barriers to the implementation of evidence-based care and provide a platform for trials and other intervention studies to reduce morbidity and mortality in cardiomyopathy. The registry consists of a prospective cohort of newly diagnosed (i.e., incident) cases and a retrospective (i.e., prevalent) cohort of existing cases from participating centres. Patients with cardiomyopathy and myocarditis will be subjected to a standardized 3-stage diagnostic process. To date, 750 patients have been recruited into the multi-centre pilot phase of the study.

CONCLUSION

The IMHOTEP study will provide comprehensive and novel data on clinical features, genetic causes, prevalence and outcome of African children and adults with all forms of cardiomyopathy and myocarditis in Africa. Based on these findings, appropriate strategies for management and prevention of the cardiomyopathies in LMICs are likely to emerge.

Prognostic value of NT-proBNP for myocardial recovery in peripartum cardiomyopathy (PPCM)

Introduction

Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure worldwide. Although a significant number of women recover their left ventricular (LV) function within 12 months, some remain with persistently reduced systolic function.

Methods

Knowledge gaps exist on predictors of myocardial recovery in PPCM. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the only clinically established biomarker with diagnostic value in PPCM. We aimed to establish whether NT-proBNP could serve as a predictor of LV recovery in PPCM, as measured by LV end-diastolic volume (LVEDD) and LV ejection fraction (LVEF).

Results

This study of 35 women with PPCM (mean age 30.0 ± 5.9 years) had a median NT-proBNP of 834.7 pg/ml (IQR 571.2–1840.5) at baseline. Within the first year of follow-up, 51.4% of the cohort recovered their LV dimensions (LVEDD < 55 mm) and systolic function (LVEF > 50%). Women without LV recovery presented with higher NT-proBNP at baseline. Multivariable regression analyses demonstrated that NT-proBNP of ≥ 900 pg/ml at the time of diagnosis was predictive of failure to recover LVEDD (OR 0.22, 95% CI 0.05–0.95, P = 0.043) or LVEF (OR 0.20 [95% CI 0.04–0.89], p = 0.035) at follow-up.

Conclusions

We have demonstrated that NT-proBNP has a prognostic value in predicting LV recovery of patients with PPCM. Patients with NT-proBNP of ≥ 900 pg/ml were less likely to show any improvement in LVEF or LVEDD. Our findings have implications for clinical practice as patients with higher NT-proBNP might require more aggressive therapy and more intensive follow-up. Point-of-care NT-proBNP for diagnosis and risk stratification warrants further investigation.

Brief psychotherapy administered by non-specialised health workers to address risky substance use in patients with multidrug-resistant tuberculosis: a feasibility and acceptability study

BACKGROUND

Only 55% of multidrug-resistant tuberculosis (MDR-TB) cases worldwide complete treatment, with problem substance use a risk for default and treatment failure. Nevertheless, there is little research on psychotherapeutic interventions for reducing substance use amongst MDR-TB patients, in general, and on their delivery by non-specialist health workers in particular.

OBJECTIVES

To explore the feasibility and acceptability of a non-specialist health worker-delivered 4-session brief motivational interviewing and relapse prevention (MI-RP) intervention for problem substance use and to obtain preliminary data on the effects of this intervention on substance use severity, depressive symptoms, psychological distress and functional impairment at 3 months after hospital discharge.

METHODS

Between December 2015 and October 2016, consenting MDR-TB patients admitted to Brewelskloof Hospital who screened at moderate to severe risk for substance-related problems on the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) were enrolled, and a baseline questionnaire administered. In the 4 weeks prior to planned discharge, trained counsellors delivered the MI-RP intervention. The baseline questionnaire was re-administered 3 months post-discharge and qualitative interviews were conducted with a randomly selected sample of participants (n = 10).

RESULTS

Sixty patients were screened: 40 (66%) met inclusion criteria of which 39 (98%) were enrolled. Of the enrolled patients, 26 (67%) completed the counselling sessions and the final assessment. Qualitative interviews revealed participants' perceptions of the value of the intervention. From baseline to follow-up, patients reported reductions in substance use severity, symptoms of depression, distress and functional impairment.

CONCLUSION

In this feasibility study, participant retention in the study was moderate. We found preliminary evidence supporting the benefits of the intervention for reducing substance use and symptoms of psychological distress, supported by qualitative reports of patient experiences. Randomised studies are needed to demonstrate efficacy of this intervention before considering potential for wider implementation.

TRIAL REGISTRATION

South African National Clinical Trials Register ( DOH-27-0315-5007 ) on 01/04/2015 ( http://www.sanctr.gov.za ).

Prognostic value of NT-pro-BNP for myocardial recovery in peripartum cardiomyopathy

Background

Peripartum cardiomyopathy (PPCM) is an important cause of pregnancy-associated heart failure and occurs in women towards the end of pregnancy or within the first five months post-partum. Though PPCM is mostly associated with left ventricular (LV) recovery, many affected women develop chronic heart failure with persistently reduced LV ejection fraction (LVEF). Despite recent advances in the treatment of PPCM, clinical predictors of myocardial recovery remain sparse.

Purpose

N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is the only clinically established biomarker with diagnostic value in PPCM. However, its prognostic value for LV recovery in PPCM remains uncertain. We aimed to establish whether NT-pro-BNP could serve as a predictor of LV recovery in PPCM, and if so, which levels would help with such risk stratification.

Methods

Women with PPCM seen at the Cardiomyopathy Clinic at Groote Schuur Hospital were recruited between 2012 and 2018. Clinical details and echocardiographic features were recorded at baseline and follow-up, and NT-pro-BNP was measured at baseline. LV recovery was defined as an LVEF of ≥50% at 12-month follow-up.

Results

This cohort of 42 women with PPCM had a mean age of 29.3±5.8 years and median parity of 2 (IQR 1–4). Almost half (45.2%) presented with a NYHA functional class III/IV. The median systolic and diastolic blood pressures were 117mmHg (IQR 105–133) and 75mmHg (IQR 68–85) respectively. The median heart was 94bpm (IQR 74–103). At diagnosis, mean LVEF was 31.1±8.4% and LV end-diastolic dimension (EDD) of 59mm (IQR 53–64), which improved to LVEF 44.5%±14.5 (p=0.001) and LVEDD 53.6mm (p=0.007) at 1 year. Median NT-pro-BNP at presentation was 915.8pg/mL (IQR 613.6–2422.5). Patients presenting with sinus tachycardia (heart rate &gt;100 bpm) had significantly higher NT-pro-BNP values (1815 vs. 728pg/mL, p=0.009) at the time of diagnosis. At presentation, NT-pro-BNP tended to correlate with LVEDD (R 0.33, p=0.04) and was inversely correlated with LVEF (R −0.39, p=0.01). Whereas initial LVEDD and LVEF did not predict LV recovery at 1 year, NT-pro-BNP at the time of diagnosis had prognostic significance. Patients without LV recovery had a significantly higher NT-pro-BNP at diagnosis (1694.1pg/mL vs. 613.1pg/mL, p=0.02). As shown in Figure 1, NT-pro-BNP of &gt;900pg/mL was associated with lower probability of LV recovery (OR 0.19 [95% CI 0.05–0.73], p=0.018).

Conclusion

We show, for the first time, that NT-pro-BNP has a prognostic value for LV recovery in PPCM. NT-pro-BNP may be useful in the risk stratification in PPCM and may be used to recommend more intensive follow-up of patients who have a NT-pro-BNP &gt;900pg/mL at diagnosis.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): This study was supported by the South African Medical Research Council and National Research Foundation of South Africa.

MRSA bacteraemia complicating amphotericin B treatment of cryptococcal meningitis

Intravenous amphotericin B is a key component of the antifungal therapy for cryptococcal meningitis recommended in South African and international guidelines. Unfortunately, its use is associated with significant toxicity including deterioration in renal function, electrolyte disturbance, anaemia and infusion reactions. Chemical phlebitis is common following administration via peripheral cannulae. This can be complicated by bacterial infection, resulting in localised cellulitis or bacterial sepsis. Here we describe two patients with cryptococcal meningitis who developed methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia during, or shortly after treatment with amphotericin B. These cases illustrate the dangers of line-related sepsis in hospitalised individuals and some of the difficulties encountered during treatment of this condition.