The Pandemic of Coronary Artery Disease in the Sub-Saharan Africa: What Clinicians Need to Know.

PURPOSE OF REVIEW: Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality globally with an accelerated increase in CVD­related death in Africa and other low­middle­income countries. This review is aimed at highlighting the burden of coronary artery disease CAD, its peculiarities as well as challenges of management in sub-Saharan Africa. RECENT FINDINGS: Recent data revealed a shift from high incidence of CVDs associated with poverty and malnutrition (such as rheumatic heart disease) initially, which are now falling, to rising incidence of other non-communicable CVDs (such as hypertension, coronary artery disease (CAD), and heart failure). Africa disproportionately bears the brunt of CVD burden and has one of the highest risks of dying from non-communicable diseases (NCDs) worldwide, which is projected to supersede communicable diseases in the future. Previous studies have shown that CAD was rare among Africans. Those studies conducted in Africa in the 1940s-1960s reported that Black Africans were almost immune to developing CAD and were even thought to have specific genetic make-up protecting them from CAD. However, the continent is now experiencing a steady rise in the prevalence of CAD associated with severe disease burden, compared to other regions of the world. The changes seen have been attributed to the current epidemiological transition with increase in CVD risk factors that are poorly controlled, lack of awareness as well as the poor health facilities to tackle the menace of the disease. The Global Burden of Disease (GBD) estimates have also shown that over the past three decades the highest contribution to CVD burden in Africa is attributed to atherosclerotic diseases, with 71.4, 37.7, and 154% increases in the burden of ischemic heart disease, stroke, and peripheral artery disease respectively. There is a steady increase of CAD prevalence in Africa as a result of increase in CV risk factors. Hypertension, obesity, diabetes, dyslipidemia, and cigarette smoking are the rapidly rising risk factors for CAD on the continent. Africa also faces challenges in diagnosis and management of CAD. There is need for increased public and health personnel awareness on prevention and control of commonly identifiable risk factors, provision of prehospital emergency services, and provision of modern therapeutic facilities for treatment of CAD including reperfusion therapy. These are priority areas where efforts could be intensified in the future with potential to improve the current rate of progress of the disease on the continent.

Hypertension and its complications are also common in low-resource specialty clinics.

The spectrum of cardiovascular diseases in an outpatient low-resource rural specialty tertiary center is not well documented. The study aimed to determine the spectrum of cardiovascular diseases in this setting. We analyzed the medical records of 748 patients with complete data between June 1 and December 31, 2017. The mean age was 49.11 ± 14.47 years. The females were younger than the males (46.21 ± 14.78 vs. 53.64 ± 13.29 p value < 0.001). Hypertensive heart disease was the most common disorder (416 cases, 55.6%). Two hundred and five patients had heart failure (49.28%), while peripartum cardiomyopathy occurred in 8.33%. Seventy-five patients had valvular heart disease, 68% due to rheumatic heart disease.

Disparities in clinical features and outcomes of peripartum cardiomyopathy in high versus low prevalent regions in Nigeria.

AIMS: The prospective, multicentre Peripartum Cardiomyopathy in Nigeria (PEACE) registry originally demonstrated a high prevalence of peripartum cardiomyopathy (PPCM) among patients originating from Kano, North-West Nigeria. In a post hoc analysis, we sought to determine if this phenomenon was characterized by a differential case profile and outcome among PPCM cases originating elsewhere. METHODS AND RESULTS: Overall, 199 (81.6%) of a total 244 PPCM patients were recruited from three sites in Kano, compared with 45 patients (18.4%) from 11 widely dispersed centres across Nigeria. Presence and extent of ventricular myocardial remodelling during follow-up, relative to baseline status, were assessed by echocardiography. During median 17 months follow-up, Kano patients demonstrated significantly better myocardial reverse remodelling than patients from other sites. Overall, 50.6% of patients from Kano versus 28.6% from other regions were asymptomatic (P = 0.029) at study completion, with an accompanying difference in all-cause mortality (17.6% vs. 22.2% respectively, P = 0.523) not reaching statistical significance. Alternatively, 135/191 (84.9%) of Kano patients had selenium deficiency (<70 µg/L), and 46/135 (34.1%) of them received oral selenium supplementation. Critically, those that received selenium supplementation demonstrated better survival (6.5% vs. 21.2%; P = 0.025), but the supplement did not have significant impact on myocardial remodelling. CONCLUSIONS: This study has shown important non-racial regional disparities in the clinical features and outcomes of PPCM patients in Nigeria, that might partly be explained by selenium supplementation.

Evaluation of segmental mandibular resection without microvascular reconstruction in patients affected by medication-related osteonecrosis of the jaw: a systematic review.

Medication-related osteonecrosis of the jaw (MRONJ) is a severe condition that affects the jaw in patients exposed to specific drugs. More often it has been described in association with bisphosphonates (BP), but nowadays it has been observed with the use of other medications, such as denosumab (a RANK ligand inhibitor and monoclonal antibody agent) and antiangiogenic drugs. Managing the condition has unfortunately proven difficult and still remains a major challenge for clinicians and surgeons. The aim of this systematic review was to identify and analyse the evidence on mandibular segmental resection in patients with advanced MRONJ. A multi-database (PubMed, MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials) systematic search was performed. Any type of study on human patients treated with antiresorptive and antiangiogenic drugs was considered. The primary aim was to understand the success of mandibular segmental resection in the short, medium, and long term, and to understand its effects before, during, and after the operation. The search yielded 11 studies that were eligible for analysis with a total of 67 patients. Of the 11 studies, seven reported no complications, and overall, postoperative complications were seen in 16 cases. Recurrence of osteonecrosis was reported in one study. The most common postoperative complication was removal of hardware (n = 11). The mean (SD) follow-up time for eight studies was 35.57 (17.73) months. According to the limited data available in the literature, mandibular segmental resection is a viable treatment that has been used successfully in patients with various stages of MRONJ. The data show a relatively high percentage of recurrence. Additional data based on a larger cohort of patients or case-control studies are necessary to justify routine use of this type of intervention in patients affected by the condition.

Clinical Features and Outcomes of Peripartum Cardiomyopathy in Nigeria.

BACKGROUND: Nigeria has the highest incidence of peripartum cardiomyopathy (PPCM) in the world. However, data on PPCM-related outcomes are limited. OBJECTIVES: The purpose of this study was to examine the clinical profile, myocardial remodeling, and survival of patients with PPCM in Nigeria. METHODS: This study consecutively recruited 244 PPCM patients (median 7 months postpartum) at 14 sites in Nigeria and applied structured follow-up for a median of 17 months (interquartile range: 14 to 20 months). Left ventricular reverse remodeling (LVRR) was defined as the composite of left ventricular (LV) end-diastolic dimension <33 mm/m2 and absolute increase in left ventricular ejection fraction (LVEF) ≥10%. LV full recovery was defined as LVEF ≥55%. RESULTS: Overall, 45 (18.7%) patients died during follow-up. Maternal age <20 years (hazard ratio [HR]: 2.40; 95% confidence interval (CI): 1.27 to 4.54), hypotension (HR: 1.87; 95% CI: 1.02 to 3.43), tachycardia (HR: 2.38; 95% CI: 1.05 to 5.43), and LVEF <25% at baseline (HR: 2.11; 95% CI: 1.12 to 3.95) independently predicted mortality. Obesity (HR: 0.16; 95% CI: 0.04 to 0.55) and regular use of beta-blockers at 6-month follow-up (HR: 0.20; 95% CI: 0.09 to 0.41) were independently associated with reduced risk for mortality. In total, 48 patients (24.1%) achieved LVRR and 45 (22.6%) achieved LV full recovery. LVEF <25% at baseline (HR: 0.66; 95% CI: 0.47 to 0.92) and regular use of beta-blockers at 6-month follow-up (HR: 1.62; 95% CI: 1.17 to 2.25) independently determined the risk for LV full recovery. Progressive reverse remodeling of all cardiac chambers was observed. In total, 18 patients (7.4%) were hospitalized during the study. CONCLUSIONS: This is the largest study of PPCM in Africa. Consistent with late presentations, the mortality rate was high, whereas frequencies of LVRR and LV full recovery were low. Several variables predicted poor outcomes, and regular use of beta-blockers correlated with late survival and LV functional recovery.

The Charging Events in Contact-Separation Electrification.

Contact electrification (CE)-charging of surfaces that are contacted and separated, is a common phenomenon, however it is not completely understood yet. Recent studies using surface imaging techniques and chemical analysis revealed a 'spatial' bipolar distribution of charges at the nano dimension, which made a paradigm shift in the field. However, such analyses can only provide information about the charges that remained on the surface after the separation, providing limited information about the actual course of the CE event. Tapping common polymers and metal surfaces to each other and detecting the electrical potential produced on these surfaces 'in-situ' in individual events of contact and separation, we show that, charges are generated and transferred between the surfaces in both events; the measured potential is bipolar in contact and unipolar in separation. We show, the 'contact-charges' on the surfaces are indeed the net charges that results after the separation process, and a large contribution to tribocharge harvesting comes, in fact, from the electrostatic induction resulting from the generated CE charges. Our results refine the mechanism of CE providing information for rethinking the conventional ranking of materials' charging abilities, charge harvesting, and charge prevention.

Avascular necrosis in sickle cell (homozygous S) patients: predictive clinical and laboratory indices.

BACKGROUND: Pathogenetic mechanism as well as laboratory and clinical correlates of osteonecrosis in sickle cell have not been fully investigated. The aim of this study is to investigate the predictive value of the steady state white cell and platelet count as well as the frequency of bone pain crisis per annum to detect sickle cell patients who will eventually develop avascular necrosis (AVN). PATIENTS AND METHODS: A 5 year retrospective analysis of 122 homozygous S (HbSS) patients, aged 6-49 years (mean age 24.7 ± 7 years), out of which 16 patients (13.1%) had developed AVN within the years under review. RESULTS: The prevalence of AVN in sickle cell patients was determined to be 13.1 per 1000. The steady state white cell count, platelet count, frequency of bone pain crisis and hematocrit, was compared in patients that develop AVN and those who had not over the period. Only the steady state platelet count was found to differ significantly ( P = 0.011) between these two patient groups and to correlate positively (Pearson correlation coefficient = -0.251) with development of AVN. The hematocrit, white cell count, and frequency of bone pain crisis were found neither to differ significantly nor correlate with the development of AVN. CONCLUSION: In conclusion, patients with a raised steady state platelet count may have a higher tendency to develop AVN and may require closer orthopedic review and prophylactic intervention.

Serum lipid profile and correlates in newly presenting Nigerians with arterial hypertension.

BACKGROUND: Arterial hypertension and dyslipidemia are modifiable cardiovascular risk factors. The multiplicative effect of these risk factors may worsen the atherogenic index of an individual. The objective of this study was to determine the pattern and prevalence of dyslipidemia in newly presenting Nigerians with arterial hypertension, as well as determine some of its correlates. METHODS: This cross-sectional study compared 115 newly presenting, age- and sex-matched individuals with arterial hypertension with 115 normotensive individuals. Fasting lipids, total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and fasting plasma glucose were estimated. RESULTS: Patients with arterial hypertension had higher body mass index (t=7.64; P=0.000), TC (t=2.95; P=0.006), and HDL-C (t=-5.18; P=0.000). The most common dyslipidemia was low HDL-C, found in both the hypertensive (44.3%) and normotensive (20.9%) patients. The prevalence of dyslipidemia in hypertensives and controls was 64% and 39%, respectively. In hypertensive patients, TC correlated positively to diastolic blood pressure (r=0.218; P=0.0019). Other positive correlates include LDL-C and age (r=0.217; P=0.020) and fasting plasma glucose (r=0.202; P=0.030) and body mass index (r=0.209; P=0.025). Among normotensive controls, TC correlated positively with LDL-C (r=0.63; P=0.000) but correlated negatively with tri glycerides (r=-0.30; P=0.001). CONCLUSION: Lipid abnormalities are common in newly presenting Nigerians with arterial hypertension. Screening of these risk factors, promotion of healthy lifestyle, and the institution of therapy is desirable to reduce their multiplicative effects.

Elimination of permanent injuries to the inferior alveolar nerve following surgical intervention of the "high risk" third molar.

We aimed to find out whether improved preoperative assessment and surgical planning with cone beam computed tomography (CT) could reduce damage to the inferior alveolar nerve when high risk impacted mandibular third molars are extracted. We recorded the presence or absence of postoperative neuropathy after extraction of 200 lower third molars in 185 patients (where cone beam CT had shown contact between the nerve and root) after treatment in the oral surgery department of King's College Hospital. All patients had had cone beam CT of the teeth after panoramic radiography had indicated increased risk of injury to the nerve during extraction. Experienced oral surgeons did all the operations and postoperative reviews. Patients reported temporary alteration of sensation after operation in 12% of teeth but it resolved in all cases and no patient reported permanent loss of sensation. Permanent sensory disturbance in the distribution of the inferior alveolar nerve after third molars have been removed can be eliminated in high risk cases if operations are planned carefully (including cone beam CT), and the procedure is done by a skilled surgeon who has an appreciation of the anatomy of the nerve and roots, and an insight into the mechanical effect of their surgical manipulation. The incidence of permanent neurosensory dysfunction in this study was zero even though all teeth were intimately related to the inferior alveolar canal.

Relationship between left ventricular diastolic function and geometric patterns in Nigerians with newly diagnosed systemic hypertension.

BACKGROUND: It is not known whether abnormalities of left ventricular diastolic function are influenced by the various cardiac geometric patterns in Nigerians with newly diagnosed systemic hypertension. OBJECTIVE: To evaluate the relationship between the parameters of left ventricular diastolic function and the geometric patterns in this group of patients. METHODS: Two-dimensional, guided M-mode echocardiography including Doppler was performed in 150 consecutive, newly diagnosed hypertensive individuals and normotensive controls aged between 35 and 74 years. Left ventricular mass index and relative wall thickness were used to classify the hypertensive individuals into four geometric patterns, and the pulsed-wave Doppler parameters obtained were used to categorise the abnormalities of diastolic function. RESULTS: Four left ventricular geometric patterns were identified: 23 (15.3%) had normal left ventricle geometry, 33 (22%) had concentric remodelling, 37 (24.7%) were found to have eccentric hypertrophy, and concentric hypertrophy occurred in 57 (38%) of the hypertensive individuals. Left ventricular diastolic dysfunction occurred more in hypertensives with concentric left ventricular geometric pattern. Increased left ventricular mass index and relative wall thickness were found to be associated with the mitral E-wave, E/A ratio and pulmonary venous flow S-wave in the hypertensives (p < 0.001). CONCLUSION: In newly diagnosed Nigerian hypertensives, the abnormalities in left ventricular diastolic function varied between the different left ventricular geometric patterns, being worst in those with concentric geometry.

Relationship between left ventricular diastolic function and geometric patterns in Nigerians with newly diagnosed systemic hypertension

Background: It is not known whether abnormalities of left ventricular diastolic function are influenced by the various cardiac geometric patterns in Nigerians with newly diagnosed systemic hypertension. Objective: To evaluate the relationship between the parameters of left ventricular diastolic function and the geometric patterns in this group of patients. Methods: Two-dimensional; guided M-mode echocardiography including Doppler was performed in 150 consecutive; newly diagnosed hypertensive individuals and normotensive controls aged between 35 and 74 years. Left ventricular mass index and relative wall thickness were used to classify the hypertensive individuals into four geometric patterns; and the pulsed-wave Doppler parameters obtained were used to categorise the abnormalities of diastolic function. Results: Four left ventricular geometric patterns were identified : 23 (15.3) had normal left ventricle geometry; 33 (22) had concentric remodelling; 37 (24.7) were found to have eccentric hypertrophy; and concentric hypertrophy occurred in 57 (38) of the hypertensive individuals. Left ventricular diastolic dysfunction occurred more in hypertensives with concentric left ventricular geometric pattern.Increased left ventricular mass index and relative wall thickness were found to be associated with the mitral E-wave; E/A ratio and pulmonary venous flow S-wave in the hypertensives (p 0.001). Conclusion: In newly diagnosed Nigerian hypertensives; the abnormalities in left ventricular diastolic function varied between the different left ventricular geometric patterns; being worst in those with concentric geometry

Na(+)-requiring mechanisms modulate capacitation and acrosomal exocytosis in mouse spermatozoa.

Mouse spermatozoa require extracellular Na+ for both capacitation and acrosomal exocytosis, but the minimum concentrations differ widely: > 1 < or = 25 mmol Na+ l-1 will support capacitation, but > 125 mmol Na+ l-1 is needed for acrosomal exocytosis in capacitated cells. Our conclusions are based on evidence obtained from sperm cells preincubated in iso-osmotic media with differing concentrations of Na+ and then analysed for occurrence of the acrosome reaction, capacitation-related changes in chlortetracycline (CTC) fluorescence and in vitro fertilization. The modified Tyrode's medium used as the control medium in these experiments contained 150 mmol Na+ l-1 and supported full sperm function. At least some of the Na+ needs to be internalized to promote the functional changes, as evidenced by the ability of the monovalent cation ionophore monensin to accelerate capacitation and trigger acrosomal exocytosis in control medium. However, in low Na+ (25 mmol l-1) medium, monensin could only modulate the transition to the capacitated state, assessed with CTC, indicating that higher concentrations of extracellular Na+ are required for initiation of acrosomal exocytosis. We suggest that changes in the composition of the female reproductive tract fluids serve to control expression of sperm functional potential. Before ovulation in the mouse, sufficient Na+ and Ca2+ are present to promote capacitation. However, the Na+ concentration is marginal for support of acrosomal exocytosis and the relatively high K+ reinforces an inhibition of exocytosis. At ovulation, the release of follicular fluid would increase the Na+ and decrease the K+ concentrations, thereby permitting full expression of fertilizing potential. Possible mechanisms that might be involved in the Na(+)-related responses, including a Na(+)-Ca2+ exchanger, a Na(+)-K+ ATPase and a Na(+)-H+ exchanger, were also investigated. If a Na(+)-Ca2+ exchanger has a role to play, it is not during capacitation per se. Incubation of sperm cells in high Na+, low Ca2+ (90 mumol CaCl2 l-1) medium that supports capacitation, followed by introduction of monensin, which would have promoted an influx of Na+ and could have, in turn, activated a Na+ out, Ca2+ in response, did not accelerate transition to the capacitated state (B pattern of CTC fluorescence). In contrast, it is possible that a Na(+)-K+ ATPase may play a role during capacitation. Incubation of suspensions in control medium plus ouabain, which would inhibit the ATPase, significantly accelerated the transition from the incapacitated to the capacitated state, although it did not trigger acrosomal exocytosis.(ABSTRACT TRUNCATED AT 400 WORDS)