ST-segment elevation myocardial infarction heart of Charlotte one-year (STEMI HOC-1) study: a prospective study protocol.

BACKGROUND: ST-segment elevation myocardial infarction (STEMI) is a clinically distinguishable yet lethal sequela of ischaemic heart disease (IHD). In sub-Saharan Africa (SSA), death due to acute STEMI is increasing. In South Africa, there is a paucity of data available on the clinical outcomes of acute STEMI within one year for individuals treated in the public healthcare sector. This study primarily seeks to determine the one-year all-cause mortality rate of acute STEMI. The study also assesses the value of serum cardiac biomarkers of myocardial damage and serum uric acid in predicting all-cause mortality in STEMI. METHODS: This is a single-centre observational prospective cohort of all consecutive individuals presenting with an acute STEMI to the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) in Johannesburg, South Africa. Research data will be sourced on admission through electronic medical records, blood laboratory results and coronary angiography reports, and at follow-up through periodic telephonic interviews and standardised echocardiograms. At least 355 eligible participants will be continuously followed over one year, and clinical outcomes will be measured 30 days, three months, six months and one year after the index hospitalisation. DISCUSSION: This study provides insights into the demographic, risk factors and clinical profiles of individuals with STEMI in South Africa. Its findings may improve the risk stratification, prognostication, and therapeutic management of STEMI patients in our setting. By comparing the clinical outcomes between the different coronary reperfusion strategies, our results may guide clinicians in providing better patient treatment, particularly in sub-Saharan Africa, where access to percutaneous coronary intervention may be limited. Furthermore, the study offers insights into the routine use of baseline serum uric acid as a potential low-cost prognostic biomarker of all-cause mortality in STEMI. Finally, this study's findings may be of public health significance to local policymakers to aid in reinforcing primary prevention strategies and developing structured referral networks for timely coronary reperfusion of acute STEMI.

Clinical characteristics and one-year all-cause mortality outcomes in Africans with dilated cardiomyopathy.

AIMS: Dilated cardiomyopathy (DCM) is a common cause of heart failure in sub-Saharan Africa (SSA). The affected individuals present with new-onset heart failure with reduced ejection fraction and no identifiable primary or secondary aetiology. We aim to describe the clinical characteristics of participants with heart failure of unknown origin. METHODS: We screened 161 participants with heart failure of unknown origin and prospectively excluded primary and secondary causes of DCM. All study participants were subjected to laboratory biochemical testing, echocardiography, cardiovascular magnetic resonance (CMR) imaging and invasive coronary angiography. RESULTS: The study comprised 93 participants with a mean age of 47.5 SD 13.1 years. Forty-six (56.1%) participants had evidence of late gadolinium enhancement (LGE) on imaging, and LGE was visualised in the mid wall in 28 (61.0%) of these participants. After a median duration of 13.4 months [interquartile range (IQR): 8.8-28.9 months], 18 (19%) participants died. Non-survivors had a higher median left atrial volume index (44.9 mL/m2 (IQR: 34.4-58.7) compared to survivors [32.9 mL/m2 (IQR: 24.5-47.0), p = 0.017)]. The rate of all-cause rehospitalisation was 29.3%, of which 17 of the 22 re-hospitalisations were heart failure related. CONCLUSION: Dilated cardiomyopathy in Africans primarily affects young males. In our cohort, this disease was associated with an all-cause mortality of 19% in one year. In SSA, large multicenter studies are required to investigate this disease's pathogenesis and outcomes.

New Biomarkers and Their Potential Role in Heart Failure Treatment Optimisation-An African Perspective.

Heart failure is a clinical syndrome resulting from various cardiovascular diseases of different aetiologies and pathophysiology. These varying pathologies involve several complex mechanisms that lead to the activation of the neurohumoral system, inflammation, angiogenesis, apoptosis, fibrosis, and eventually adverse cardiac remodelling associated with a progressive decline in cardiac function. Once a diagnosis is made, the cardiac function has a gradual decline characterised by multiple hospital admissions. It is therefore imperative to identify patients at different stages of the heart failure continuum to better risk stratify and initiate optimal management strategies. Biomarkers may play a role in the diagnosis, prognostication, and monitoring response to treatment. This review discusses the epidemiology of heart failure and biomarkers commonly used in clinical practice such as natriuretic peptides and cardiac troponins. In addition, we provide a brief overview of novel biomarkers and genetic coding and non-coding biomarkers used in the management of patients with heart failure. We also discuss barriers that hinder the clinical application of novel biomarkers. Finally, we appraise the value of polygenic risk scoring, focusing on sub-Saharan Africa.

Ultrasound Hepatic Vein Ratios Are Associated With the Development of Acute Kidney Injury After Cardiac Surgery.

OBJECTIVE: The authors investigated the use of hepatic venous and right-heart ultrasound parameters in predicting cardiac surgery-associated acute kidney injury (AKI). DESIGN: This was a prospective, contextual, descriptive two-center study. Blood tests,clinical and ultrasound data were obtained preoperatively, and postoperative day one, and day four. The hepatic vein, inferior vena cava, and right-heart Doppler ultrasound parameters were obtained and analyzed. SETTING: The sites of the study were Johannesburg, South Africa, and Aarhus, Denmark. PARTICIPANTS: Adult patients who satisfied inclusion criteria, between August 2019 and January 2020, were included, with a total of 152 participants. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The median (interquartile range) age of patients was 68 (55-73) years, predominantly male, and the majority were hypertensive. Of 152 patients analyzed, 54 (35%) patients developed AKI. Among these, 37 (69%) were classified as Kidney Disease: Improving Global Outcomes (KDIGO) stage I, 11 (20%) as stage II, while six (11%) were stage III. Age (adjusted odds ratio [AOR] 1.05, 95% confidence interval [CI] 1.00-1.10 p = 0.031), The European System for Cardiac Operative Risk Evaluation (EuroSCORE) II (AOR 1.43, 95% CI 1.14-1.80, p = 0.005], and preoperative serum creatinine (AOR 1.04, 95% CI 1.01-1.08, p = 0.013) were predictive of AKI. Those who developed AKI had experienced longer cardiopulmonary bypass (CPB) times (p < 0.001). Preoperatively, hepatic vein S-wave measurements were significantly higher in patients with AKI (p < 0.05). On postoperative day one (D1), the hepatic vein flow ratios of patients with AKI were significantly decreased, driven by low S waves and high D waves, and accompanied by significantly elevated central venous pressure (CVP) levels. CVP levels on D1 postoperatively were predictive of AKI (AOR 1.31, 95% CI 1.11-1.55, p = 0.001). Measurements of right ventricular (RV) base, tricuspid annular plane excursion (TAPSE), and inferior vena cava were not associated with the development of AKI (p > 0.05). CONCLUSION: There was an association between the development of AKI and a decrease in hepatic flow ratios on D1, driven by low S-wave and high D-wave velocities. The presence of venous congestion was reflected by significantly elevated CVP values, which were independently associated with AKI on D1. RV base and TAPSE measurements were, however, not associated with AKI. These parameters may reflect perioperative circumstances, including prolonged CPB times and potential fluid management, which can be modified in this period.

Perioperative Doppler measurements of renal perfusion are associated with acute kidney injury in patients undergoing cardiac surgery.

Acute kidney injury (AKI) is a frequent and severe complication in cardiac surgery. Normal renal function is dependent on adequate renal perfusion, which may be altered in the perioperative period. Renal perfusion can be assessed with Doppler measurement. We aimed to determine the association between Doppler measurements of renal perfusion and the development of AKI. This was a prospective, observational study of 100 patients with ≥ one risk factor for postoperative AKI undergoing open-heart surgery. Doppler ultrasound examinations were performed before surgery and on the first and fourth postoperative day. AKI was defined according to the KDIGO criteria and subdivided into mild (KDIGO stage 1) and severe AKI (KDIGO stage 2 + 3). Thirty-three patients developed AKI, 25 developed mild and eight developed severe AKI. Abnormal renal venous flow pattern on the first postoperative day was significantly associated with the development of severe AKI (OR 8.54 (95% CI 1.01; 72.2), P = 0.046), as were portal pulsatility fraction (OR 1.07 (95% CI 1.02; 1.13), P = 0.005). Point-of-care Doppler ultrasound measurements of renal perfusion are associated with the development of AKI after cardiac surgery. Renal and portal Doppler ultrasonography can be used to identify patients at high risk or very low risk of AKI after cardiac surgery.

Prevalence and significance of isolated left ventricular non-compaction phenotype in normal black Africans using echocardiography.

BACKGROUND: Several large, prospective screening studies of predominantly Caucasian patients have suggested that hypertrabeculation may not necessarily be pathologic unless there is concomitant left ventricular (LV) dysfunction, LV dilatation, history of arrhythmia, family history, or characteristic gene mutations. This conundrum may be magnified in blacks, in whom hypertrabeculation and LV hypertrophy is more common. We therefore investigated the frequency of hypertrabeculation/isolated LV noncompaction (ILVNC) phenotype in normal black Africans and evaluated LV function using sensitive measures of deformation and twist. METHODS: Two hundred and fifty-three volunteers were recruited and evaluated according to strict inclusion and exclusion criteria. Their mean age was 36.3 ± 12.2 years. RESULTS: Trabeculations were found in 12 (4.74%) participants. Three (1.2%) subjects had ≥ 4 LV trabeculations. The LV apex was the most common anatomical site for the location of trabeculations. Subjects with trabeculations were more likely to be males of a younger age, and had greater LV end-diastolic and end-systolic parameters and lateral e'. However, 0.8% of the population fulfilled the Stollberger criteria, and none fulfilled the Jenni, Milwaukee, or Baragwanath criteria. All subjects in this study had normal rotation patterns with no differences in rotational parameters or net twist. CONCLUSIONS: Trabeculations may be found as a normal variant in black Africans. Assessing trabeculations alone may infer ILVNC; however, utilizing the more comprehensive ILVNC criteria enables differentiation of a possible LVNC phenotype. Normal individuals with hypertrabeculation have normal LV function and normal rotation patterns, with no differences in rotational parameters or net twist.

Echocardiographic Indices of the Left and Right Heart in a Normal Black African Population.

BACKGROUND: It is unknown whether ethnic differences occur with regard to right heart echocardiographic parameters. The aim of this study therefore was to establish normative values of left and right heart parameters in a black African population and to evaluate the effect of age and body mass index (BMI) on specific right ventricle (RV) parameters. METHODS: Two hundred fifty-three normal subjects were prospectively studied. A standardized echocardiographic examination was conducted with the RV focused view used to derive RV measurements. All left and right heart measurements were made in accordance with the American Society of Echocardiography 2015 chamber guideline recommendations. Right ventricle free wall strain was assessed using an RV focused apical four-chamber view. RESULTS: The average age was 36.3 ± 12.2 years, and 59% of patients were female. The mean left ventricular ejection fraction was 62.3% ± 5.7%. The RV linear measurements (RV base, 31.0 ± 4.5 mm; midcavity, 26.3 ± 5.8 mm) were not associated with sex, age, or BMI except for the RV length (64.6 ± 8.9 mm), which was greater in male patients. Tricuspid annular plane systolic excursion (TAPSE) was 21.7 ± 2.8 mm, fractional area change was 42.1% ± 5.5%, tricuspid annular peak systolic velocity RV S' was 12.1 ± 1.9 m/sec, and RV free wall strain was -31.5% ± 8.6%. Age and BMI were not associated with right atrial (RA) volumetric measurements, RV linear measurements, or any RV functional parameters except TAPSE and RV A', which increased with BMI. CONCLUSIONS: This study establishes normal left and right heart parameters in a black African population. Aging was not associated with RA or RV parameters except for RV E' and A'. BMI does not affect RA/RV measurements but may cause variability in TAPSE and RV A'.

Left atrial volume and strain parameters using echocardiography in a black population.

AIMS: Left atrial (LA) volume is an important predictor of morbidity and mortality in cardiovascular disease. Left atrial strain is a feasible technique for assessing LA function. The EchoNoRMAL study recently highlighted the possibility that ethnic-based differences may exist in LA size. There is a paucity of data regarding LA parameters in an African population. We sought to establish normative values for LA volumetric and strain parameters in a black population. METHODS AND RESULTS: This cross-sectional study comprised 120 individuals between 18 and 70 years of age. Left atrial volumes were measured by biplane Simpson's method, and strain parameters were measured using Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software. The mean age was 38.7 ± 12.8 years (50% male). Maximum LA volume indexed (LAVi), pre-atrial LAVi, and minimum LAVi were 19.7 ± 5.9, 12.2 ± 4.4, and 7.7 ± 3.2 mL/m2, respectively. Females had a higher LAVi compared with males (20.9 ± 6.3 vs. 18.6 ± 5.3 mL/m2, P = 0.04). Peak global longitudinal strain in the reservoir phase (ɛR) was 39.0 ± 8.3%, and the peak LA strain in the contractile phase (ɛCT) was -2.7 ± 2.5%. No gender differences were noted in ɛR. Body surface area, age, and weight were the main determinants of ɛR on multivariate linear regression analysis. CONCLUSION: The data reported in this study establish the normal reference values for phasic LA volumes and strain in a normal black population and serve as a platform for future studies.

Effects of age on left atrial volume and strain parameters using echocardiography in a normal black population.

OBJECTIVE: Normal cut-off values for left atrial (LA) size and function may be altered by aging and ethnic differences. No age-related reference values for LA volumetric measurements or LA strain exist in Africans. We aimed to establish normal age-appropriate values of LA size and function in black Africans. Additionally, we studied the correlation between age, LA strain and volumetric parameters. METHODS: In this prospective, cross-sectional study of 120 individuals (mean age 38.7 ± 12.8 years, 50% men), subjects were classified into four age groups: 18-29, 30-39, 40-49 and 50-70 years. LA volumes were measured by biplane Simpson's method, and Philips QLAB 9 (Amsterdam, The Netherlands) speckle-tracking software was used to measure LA peak strain in the reservoir (ƐR) and contractile phase (ƐCT). RESULTS: No significant differences in the maximum and minimum LAVi were noted among the four age categories (P = 0.1, P = 0.2). LA volumetric function assessment showed no difference in reservoir function between age groups (P > 0.05), conduit function decreased with advancing age (r = -0.3, P < 0.001) and booster function displayed a significant increase with age (LA active emptying volume index, P = 0.001). There was a significant decrease in LA ƐR (P < 0.0001) in the older age groups, whereas ƐCT remained unchanged (P = 0.27). CONCLUSION: Age-related changes in LA reservoir, conduit and contractile function in black Africans are similar to those observed in other populations, as was the trend of declining ƐR with advancing age. The preservation of ƐCT with increasing age requires further analysis.