Point-of-care NT-proBNP for the screening of PREGnancy-related Heart Failure – the PREG-HF study

Introduction

Cardiovascular disease is an important cause of maternal mortality worldwide. However, diagnosing heart failure (HF) during pregnancy remains challenging. Patients with HF present with symptoms that are often attributed to the physiological changes of pregnancy. Although the measurement of natriuretic peptides (such as NT-proBNP) has been recommended as a cost-effective screening test for HF, its value in predicting underlying structural heart disease on echocardiography during pregnancy is unclear.

Purpose

To evaluate the accuracy of point-of-care (POC) NT-proBNP to predict echocardiographic evidence of structural heart disease in pregnant women.

Methods

All consecutive consenting pregnant women with symptoms of HF (New York Heart Association functional class [NYHA FC] II–IV), who underwent echocardiography at Groote Schuur Hospital (a tertiary hospital in South Africa) between 1 March 2021 and 15 March 2022 were recruited and compared with asymptomatic pregnant women (NYHA FC I). Demographic and obstetric data were collected, as well as clinical and echocardiographic parameters. POC NT-proBNP was measured; a receiver operating characteristic (ROC) curve was used to determine the level of NT-proBNP that would have the best predictive value for detecting structural heart disease on echocardiography.

Results

We included 121 women with a median age of 31.3 years (IQR 24.9–36.4) and a median gravidity of 3 (2–4), mostly in their third trimester of pregnancy (75.2%). Symptomatic women (66.1%) presented mainly with dyspnoea (92.5%) and fatigue (73.8%). Most common signs of HF were peripheral oedema (46.8%), jugular venous distension (17.7%) and pulmonary crackles (17.7%). Overall, the median POC NT-proBNP was 98pg/ml (60–506) but was not statistically different between symptomatic and asymptomatic participants. However, NT-proBNP levels were significantly elevated in those with left ventricular (LV) dilatation (376 [86–744] vs 65 [60–191], p=0.001), left atrial enlargement (395 [65–744] vs 60 [59–108], p<0.001), LV systolic dysfunction (510 [113–1668] vs 65 [60–210], p<0.001), diastolic dysfunction (300 [77–1450] vs 78 [60–257], p=0.031), mitral regurgitation (167 [60–672] vs 78 [60–243], p=0.038) and pericardial effusion (440 [81–1031] vs 71 [60–243], p=0.011) (Figure 1). An NT-proBNP of <200pg/ml had the highest negative predictive value (83%) to rule out structural heart disease (AUC 0.68 [0.59–0.77]). Patients with NT-proBNP of ≥200pg/ml were at increased risk of having echocardiographic evidence of structural heart disease (diagnostic odds ratio 4.9 [95% confidence interval 2.0–11.7]).

Conclusion

In this cohort of pregnant women with symptoms suggestive of HF, POC NT-proBNP identified those with structural heart disease with acceptable discrimination. POC NT-proBNP testing might be particularly useful as a screening test in settings where pregnant women do not readily have access to echocardiography.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): World Heart Federation Salim Yusuf Emerging Leaders Programme

Cardiorespiratory fitness and electroanatomical remodelling in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial fibrillation (AF) is the most common clinically-relevant arrhythmia. Its initiation and maintenance is linked to the presence cardiovascular risk factors such as hypertension and obesity. Higher cardiorespiratory fitness (CRF) has been associated with a better prognosis. However, specific electroanatomical features associated with baseline CRF have not been described. 

Purpose

Compare electroanatomical substrate across exercise capacity levels in patients with AF

Methods

Patients referred for de novo AF radiofrequency ablation at the Centre for Heart Rhythm Disorders from August 2017 until June 2020 were screened for inclusion and CRF was evaluated in metabolic equivalents (METs) by a symptom-limited maximal treadmill exercise test using the standard Bruce protocol prior to ablation. Predicted CRF was calculated based on established equations and patients were categorized according to the percentage of predicted CRF achieved; low (<85%), adequate (85-100%) and high (>100%). Total mean and regional peak-to-peak bipolar voltages, percent of low voltage areas (% LVA), conduction velocity (CV) and percent of complex fractionated electrograms (% CFE) in sinus rhythm were compared across groups. 

Results

There were no between-group differences in baseline characteristics, medication use or echocardiographic features. Total mean voltage was significantly lower in the low CRF group compared to both adequate and high CRF. Compared to the high CRF group, roof (3.25 ± 1.2 mV vs 1.9 ± 1.3 mV, p < 0.05), posterior (3.8 ± 1.8 mV vs 1.7 ± 0.9 mV, p < 0.001) and inferior mean voltages (3.4 ± 2 mV vs 1.6 ± 0.7 mV, p < 0.05) were significantly lower in the low CRF group (figure 1A). Furthermore, compared with the adequate CRF group, mean voltages were significantly lower in the posterior (3.7 ± 1.5 mV vs 1.7 ± 0.9 mV, p < 0.001), inferior (3.4 ± 1 mV vs 1.6 ± 0.7 mV, p < 0.001) and lateral (4.2 ± 2.2 mV vs 2.1 ± 1.4 mV, p < 0.05) walls of the low CRF group. Anterior and septal mean voltages were not significantly different across CRF groups (P for trend = 0.07, 0.3 and 0.15, respectively). Conduction velocities were not significantly different across groups. The inferior %LVA was significantly higher in the low CRF (5.6 ± 6%) compared to adequate CRF group (23 ± 18%) (p < 0.05) (figure 1B). Total and regional % CFE was higher in the low CRF compared to adequate and high CRF.

Conclusion

Participants in the lower baseline CRF category showed significant reductions in regional voltages along with higher fractionation with preserved conduction velocities. Research on the effect of physical activity and CRF on left atrial arrhythmogenic substrate is required.

Abstract Figure. Global and regional mV and % LVA by CRF

Sickle cell retinopathy and other chronic complications of sickle cell anemia: A clinical study of 84 Sub-Saharan African cases (Cameroon)

OBJECTIVE

Sickle retinopathy is a severe complication of sickle cell disease than can lead to blindness. We aim to describe the epidemiology of sickle retinopathy in homozygous sickle cell (SS) African patients and to analyze its association with non-ophthalmologic disease complications of sickle cell anemia.

METHODS

We conducted a nested study within the CADRE cohort in Cameroon. Eighty-four consecutive SS outpatients, aged 10 years and older, with no visual symptoms, underwent an ophthalmologic examination. Mean age was 23±10 years. Clinical and biological features were compared between patients with and without sickle retinopathy. We compared the prevalence of the clinical complications and main biological characteristics in patients with and without sickle retinopathy using a univariate logistic regression. The same analysis was used to compare the patients with non-proliferative sickle retinopathy to those with proliferative sickle retinopathy. Statistical analyses were done using the R software (version 3.1.2).

RESULTS

Fifty-two patients (62%) displayed sickle retinopathy, among them 23 (27%) had a non-proliferative sickle retinopathy, and 29 (35%) had proliferative sickle retinopathy. Patients with proliferative sickle cell retinopathy had a mean age of 28±11 years. Sickle retinopathy was associated with higher hemoglobin level (P=0.047) and fewer leg ulcers (P=0.018). Proliferative SR was associated with increasing age (P=0.008) and male sex (P=0.025) independently of the hemoglobin level.

CONCLUSIONS

Sickle retinopathy is particularly frequent in sub-Saharan sickle cell SS patients, which advocates for early systematic screening.

Epidemiology of venous thromboembolism in Africa: a systematic review

Essentials Venous thromboembolism (VTE) is among the three main causes of cardiovascular disease worldwide. This review is the first to summarize the epidemiology of VTE in African populations. The prevalence of VTE in Africa is high following surgery, in pregnancy and post-partum. At least one quarter of patients at risk of VTE in Africa are not receiving prophylaxis.

SUMMARY

Background Venous thromboembolism (VTE) is among the three leading causes of cardiovascular disease worldwide. Despite its high burden, there has been no previous study summarizing the epidemiology of VTE in African populations. Hence, we conducted this systematic review to determine the prevalence, incidence and mortality associated with VTE, and to evaluate the use of VTE prophylaxis in Africa. Methods We searched PubMed, Scopus and African Journals Online to identify articles published on VTE in Africa from inception to November 19, 2016, without language restriction. The reference list of eligible articles were further scrutinized to identify potential additional studies. Results Overall, we included 21 studies. The great majority of the studies yielded a moderate risk of bias. The prevalence of deep vein thrombosis (DVT) varied between 2.4% and 9.6% in postoperative patients, and between 380 and 448 per 100 000 births per year in pregnant and postpartum women. The prevalence of pulmonary embolism (PE) in medical patients varied between 0.14% and 61.5%, with a mortality rate of PE between 40% and 69.5%. The case-fatality rate after surgery was 60%. Overall, 31.7-75% of the patients were at risk of VTE, and between 34.2% and 96.5% of these received VTE prophylaxis. Conclusion The prevalence of VTE and associated mortality are high following surgery, and in pregnant and postpartum women in Africa. At least one-quarter of patients who are at risk for VTE in Africa are not receiving prophylaxis. These results are generated from studies with small sample size, highlighting an urgent need for well-designed studies with larger sample size to evaluate the true burden of VTE in Africa.

Ketosis-prone atypical diabetes in Cameroonian people with hyperglycaemic crisis: frequency, clinical and metabolic phenotypes

AIM

It is unclear whether ketosis-prone diabetes is a specific type or a subtype of Type 2 diabetes. We aimed to describe the clinical and metabolic features of ketosis-prone diabetes in a sub-Saharan population.

METHODS

We consecutively enrolled and characterized 173 people with non-autoimmune diabetes admitted for hyperglycaemic crisis at the Yaoundé Central Hospital, Cameroon. Blood samples were collected for fasting glucose, HbA_1c , lipid profile and C-peptide assays with insulin resistance and secretion estimation by homeostasis model assessment. People were classified as having Type 2 diabetes (n = 124) or ketosis-prone diabetes (n = 49). Ketosis-prone diabetes was sub-classified as new-onset ketotic phase (n = 34) or non-ketotic phase (n = 15).

RESULTS

Ketosis-prone diabetes was found in 28.3% of the hyperglycaemic crises. Age at diabetes diagnosis was comparable in Type 2 and ketosis-prone diabetes [48 ± 14 vs 47 ± 11 years; P = 0.13] with a similar sex distribution. Overall BMI was 27.7 ± 13.4 kg/m² and was ≥ 25 kg/m² in 55.8% of those taking part, however, 73.5% of those with ketosis-prone diabetes reported weight loss of > 5% at diagnosis. Blood pressure and lipid profile were comparable in both types. Ketosis-prone diabetes in the ketotic phase was characterized by lower insulin secretion and higher serum triglycerides compared with non-ketotic ketosis prone and Type 2 diabetes. Type 2 and ketosis prone diabetes in the non-ketotic phase were comparable in terms of lipid profile, blood pressure, waist-to-hip ratio, BMI and fat mass, insulin secretion and insulin resistance indices.

CONCLUSIONS

Ketosis-prone diabetes is likely to be a subtype of Type 2 diabetes with the potential to develop acute insulinopenic episodes.