Etat des lieux de la prise en charge des syndromes coronariens aigus en Afrique sub-Saharienne : Résultats des cinq dernières années révélant une situation alarmante à Yaoundé, Cameroun.

 

CN NGANOU-GNINDJIO^1,2,*, JR NKECK¹, AT TCHOUANLONG³, DB ESSAMA¹, AP MENANGA^1,4

 

 

RESUME

 

Contexte et Objectif : Afin de réduire le fardeau des maladies cardiovasculaires dans les pays à revenus faibles ou intermédiaires, il est crucial de faire régulièrement un état des lieux sur l’épidémiologie et la prise en charge notamment. L’objectif de notre travail était de décrire le niveau de prise en charge des patients atteints de syndromes coronariens aigus (SCA) au Cameroun, micro-écosystème de l’Afrique sub-Saharienne.

Méthodes : Dans une étude transversale et multicentrique à collecte de données rétrospective, nous avons examiné les dossiers médicaux d’adultes traités pour SCA dans trois hôpitaux de référence de la ville de Yaoundé (capitale du Cameroun) entre janvier 2016 et juin 2020. Les données recueillies étaient les paramètres sociodémographiques, cliniques, biologiques et électrocardiographiques pertinents, ainsi que thérapeutiques et le pronostic.

Résultats : Les SCA représentaient respectivement 2,51 % et 1,21 % des consultations d’urgence et des hospitalisations dans les services de cardiologie. L’examen des cas confirmés révèle que l’âge moyen est   de 60,8 ±13,6 ans. La prédominance est masculine avec  (61 %).  L’hypertension artérielle (80,4 %) et le mode de vie sédentaire (67,4 %) étaient les facteurs de risque cardiovasculaires prédominants. Par ailleurs, 17,5 % des patients avaient un événement cardiovasculaire antérieur. Concernant la présentation clinique, l’angine de poitrine était retrouvée dans 71.7%des cas, les stades I et II de Killip dans 84.8% des cas, et l’infarctus du myocarde avec un sus décalage du segment ST dans 54% des cas. Le transfert à l’hôpital était dans 54,3% des cas au moyen d’un véhicule personnel, au cours d’un délai moyen de 24 ±35,9 heures. Seuls 7/25 des patients présentant une indication pour la thrombolyse l’ont reçue. Six patients (13 %) ont été référés pour angiographie coronaire, à 418 km de Yaoundé. Le taux de complications était de 54,3 %, principalement, d’ordres hémodynamiques et rythmiques dans 37% et 26% des cas, respectivement. La mortalité intra-hospitalière était de 13 %.

Conclusion : La situation de la prise en charge des SCA au Cameroun est alarmante. Il  est urgent d’améliorer le système de soins de santé afin de faire face au fardeau croissant des maladies cardiovasculaires, notamment celui des SCA.

 

 

MOTS CLES

 

Syndromes coronariens aigus; Épidémiologie; Traitement; Yaoundé-Cameroun.

 

 

 

SUMMARY

 

Background and Aims: On the way to reduce the burden of cardiovascular diseases in Low and Middle-Income Countries, it is crucial to update their epidemiology and state of management regularly. We aimed to describe the state of care of patients with acute coronary syndromes (ACSs) in Cameroon, a micro-ecosystem of sub-Saharan Africa.

Methods: In a cross-sectional and multicentric study, we reviewed the clinical records of adults treated for ACS in three referral hospitals in Yaoundé (Cameroon’s capital) between January 2016 and June 2020. Data collected were sociodemographic, relevant clinical, biological and electrocardiographic signs, as well as management and prognosis.

Results: ACSs represented 2.51% and 1.21% of emergency consultations and cardiology hospitalizations, respectively. The review of confirmed cases reveals: mean age of 60.8 ±13.6 years, 61% males, hypertension (80.4%) and sedentary lifestyle (67.4%) as predominant cardiovascular risk factors, 17.5% with a previous cardiovascular event. Clinically, the presentation was typical angina in 71.7%, Killip stages I or II in 84.8%, and ST-segment Elevation Myocardial Infarction in 54%. Transfer to the hospital was most often done by personal vehicle (54.3%), with average time management of 24 ±35.9 hours. Only 7/25 patients with an indication for thrombolysis received it. Six patients (13%) were referred for coronary angiography, 418 km from Yaoundé. The complication rate was 54.3%, mainly hemodynamic (37%) and rhythms disorders (26%). The in-hospital mortality was 13%.

Conclusion: The state of care for ACS in Cameroon is alarming. There is an urgent need to improve the health care system to address the growing burden of cardiovascular diseases, especially in the case of ACS.

 

 

 

KEY WORDS

Acute coronary syndromes; Epidemiology; Management; Yaounde-Cameroon.

 

 

 

1.Internal Medicine and Specialties Department, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon.

2. Cardiology department, Yaoundé Central Hospital, Yaoundé, Cameroon.

3. Higher Institute of Health Sciences, Université des Montagnes, Bangangté, Cameroon.

4. Internal Medicine department, Yaoundé General Hospital, Yaoundé, Cameroon.

 

 

Adresse pour correspondance 

Chris Nadège Nganou-Gnindjio, MD

Phone number: +237 698214610

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

FMSB/ University of Yaoundé 1, Cameroon

 

 

INTRODUCTION

 

 

Sub-Saharan Africa (SSA) has already witnessed the transition in adults’ etiological causes of death from communicable to non-communicable diseases (NCDs). According to the World Health Organization (WHO), cardiovascular diseases (CVDs) are currently the leading cause of death in Africa as well as the rest of the world, with one million deaths in 2013 [1,2].  Acute coronary syndrome (ACS), once considered a rare event in SSA, is nowadays, with the increase of cardiovascular risk factors in this population, a frequent cause of disability and mortality [3, 4]. The prognosis of patients affected by ACS is even worse in countries where access to health facilities is limited, financial resources are insufficient, health insurance is lacking, hospitals are insufficiently equipped, and preventive medicine is missing [5]; this is the case of Cameroon as well as many other SSA countries. To face the high burden of ACSs, it is important to regularly evaluate the state of management of the disease and formulate appropriate recommendations to improve practices and be useful in other low and middle-income countries (LMICs). In the present study, we reviewed the management of patients with ACSs received in referral hospitals of Yaoundé, Cameroon, for the five past years (2016-2020) and suggested contemporary insights that we believe will serve to improve the situation of LMICs in the face of this increasing prevalence of CVDs.

 

 

METHODS

 

Study design and Setting

 

It was a cross-sectional and multicentric study; carry out from January 01, 2020, to June 31, 2020, in three referrals hospitals in Yaoundé: Yaoundé Emergency Centre (YEC), Yaoundé General Hospital (YGH), and Yaoundé Central Hospital (YCH).

Data were collected retrospectively over four years, from January 01, 2016, to December 31, 2019, and prospectively over six months, from January 01, 2020, to June 31, 2020, on clinical files.

 

Participants

 

We have included any records of patients aged 18 years or older diagnosed with an ACS according to the European Society of Cardiology (ESC) recommendations, based on their clinical presentation, electrocardiogram, and cardiac-specific biomarkers (troponin I). For the case analysis, we only retained records of patients with a confirmed diagnosis of ACS.

 

Sample size estimation

 

The sample size was estimated at 44 participants using the Cochran (1965:75) formula, with 95% power, 0.05 margin of error, and ACS prevalence (3.02%) obtained from the study of Boombhi et al. in 2016[6].

 

Data measurement

 

Data collected were sociodemographic (age, gender, profession, residence (urban or rural), level of education and marital status), clinical characteristics (signs, cardiovascular risk factors, comorbidities, body mass index, blood pressure) and the relevant paraclinical results (ECG, troponin levels, blood sugar level, blood urea nitrogen, creatinemia, and cardiac ultrasound parameters). We also reported management data: transfer of the patient to the hospital, time to management, procedures performed, survival, and complications up to discharge and at one month of follow-up.

 

Definition of terms

 

Blood pressure was classified according to the European Society of Hypertension/ESC Guidelines [7]. The severity of myocardial infarction was staged by Killip’s classification [8].Altered left ventricular ejection fraction (LVEF) on cardiac ultrasound was defined as less than 50%. The Glomerular Filtration Rate was calculated using the Modification of Diet in Renal Diseases formula.

 

Ethics approval and consent to participate

 

The study was approved by the Institutional Ethics Committee of the Université des Montagnes (Cameroon) ref N° 2020/130/UdM/PR/CIE. We have obtained the administrative authorization for research from all the hospitals that were concerned. And all subjects provided written informed consent in accordance to the Helsinki Declaration.

 

Statistical analysis

 

Data were analysed using Microsoft Excel 2010 and SPSS version 23.0. Quantitative variables are presented by their means and standard deviation, while qualitative variables are presented with their effective and proportions.

 

RESULTATS

 

 

From January 2016 to June 2020, we recorded 125 cases of ACS at the YEC out of 5008 consultations, which made a prevalence of 2.51% at the emergency. In the cardiology departments of the YCH and the YGH, we identified 40 cases out of 3667 hospitalizations, which made a prevalence of 1.21%. Due to poor medical record management, many records were not found (72, 43.6%). Of those retrieved, a large majority did not have the required information to confirm ACS diagnosis. We, therefore, included only the records of patients with a confirmed diagnosis (46).

 

Baseline characteristics of the sample

 

26 (61%) were male in the study sample, and the sex ratio was 1.56. The population’s average age was 60.8 ±13.65 years (58.39 ±11.6 years for men and 64.56 ±15.6 years for women). As presented in Table 1, the most represented age groups were [60; 69 years [(30.4%) and [50; 59 years [(28.3%). The majority of participants were urban residents (91.3%), married (73.9%), retired (34.8%), or employed in civil servant (37%), with a minimal secondary educational level (65.2%). The predominant CVD risk factors were: hypertension (80.4%), sedentary lifestyle (67.4%), obesity (BMI≥30kg/m²; 39.1%), and type 2 diabetes (32.6%). Respectively 8 (17.5%) and 4 (8.7%) participants had already had a cardiovascular and cerebrovascular event.

 

Clinical presentation of ACS

 

Chest pain was present in 89.1%, with 71.7% of typical angina pain. Rest dyspnoea was the second most common sign (30.4%). Blood pressure was elevated in 74% of cases. Killip stages I and II were predominant in 52.2% and 32.6%, respectively. On ECG, sinus rhythm was recorded in 84.6% of the cases; 54% of the participants had STEMI, while 28% and 18% had NSTEMI and unstable angina. Q-wave was found in association with STEMI in 13 (28.3%) participants and isolated in 26.1% of the cases, indicating an old myocardial infarction. The ECG abnormalities found were predominantly in the anteroseptal (41.3%) and inferior (23.9%) territories. On echocardiography, 50% had an alteration in the LVEF, and 67.6% had hypo/akinesia. See Table 2.

 

Management of ACS

 

Table 3 shows that most patients came directly from their residence (60.1%), while 39.1% were referred from a health facility for better care. The most common means of transport was the non-medical automobile (54.3%). Only 5 (10.9%) participants were transported by ambulance. The average time between the onset of symptoms and treatment was 24.02 (±35.95) hours; only 28.3% had started treatment within 6 hours of the beginning of symptoms.

Of 25 patients on who thrombolysis was indicated, only 7 (28%) received it. The molecules used were streptokinase (6/7) and alteplase (1/7). Six patients (13%) were evacuated for coronary angiography with angioplasty at the Shisong Interventional Cardiology Centre, located in Kumbo, North-West Region, and 418 km from Yaoundé (450 minutes by road).

The other drugs prescribed were antiplatelet agents (100%), anticoagulants (89.1%), statins (78.2%), beta-blockers (65.2%), and analgesics: (43.5%), and proton pump inhibitors (71.7%).

 

Prognosis of ACS

 

The rate of complications in our study was 54.3%. The in-hospital mortality was 13%. The cumulative mortality at one month was 15.2%. Hemodynamic complications, including congestive heart failure and cardiogenic shock, accounted for 37%. Rhythms disorders accounted for 26%, while conduction disorders were retrieved in 13.03% of participants (Table 3).

 

 

DISCUSSION

 

We aimed to reassess the current situation in Cameroon concerning the management of ACS. In the present study, we found a prevalence of 2.51% in YEC and a prevalence of 1.21% in the cardiology department YCH and YGH, confirming the hypothesis of epidemiological growth of this condition, which still shares the same epidemiological characteristics in terms of predominant sex (male), age (above 50 years) and other risk factors. In 1997, Kingue et al. found a prevalence of 0.96% in the YCH. At the same period in Douala, Kotto et al. did not find any CAD in his series of patients hospitalized in cardiology, noting the exploration difficulties [9, 10]. This increase in prevalence can be explained by the rise in classical cardiovascular risk factors, including hypertension, diabetes, sedentary lifestyle, and obesity, whose prevalence is rising in Cameroon, affecting more young [11]. These modifiable risk factors should lead to long-term epidemiological interventions to reduce the incidence of CVD. In addition, we have experienced the improvement in diagnostic strategies of ACS in the country, and the life expectancy has risen, especially for patients with chronic diseases whose treatment favours an increase in cardiovascular risks, such as Human Immunodeficiency Virus infection [12].This rise in ACS prevalence is not specific to Cameroonians, and other African countries are notably subject to this phenomenon [13, 14].

With the increase in the incidence of ACSs, it is even more essential to look at the state of management to guide public health interventions. In our study, we found an alarming situation on several levels. Firstly, pre-hospital care is lacking, with the transfer of patients done in most cases by non-medical means. This can be explained by a lack of medicalized ambulances, a lack of information for the population, and a cruel deficit in the organization and emergency management in the pre-hospital phase. Secondly, the time required for management is excessive (24 hours in the mean), with a lack of respect for timing, even within hospitals, making emergency reperfusion strategies difficult. Finally, the means of management in hospitals are limited, particularly for reperfusion measures, due to a technical platform that is often inadequate, coupled with a lack of financial means of patients given the absence of health coverage in our current context. In Yaoundé, the absence of an interventional cardiology centre made thrombolysis the only reperfusion treatment available in the emergency. Of 25 patients with an indication for thrombolysis (ST+ infarcts), only seven had received it. The limitation to the use of thrombolysis was mainly the long delay between the onset of symptoms and management—secondly, the accessibility of this treatment given the high cost of thrombolytics. Streptokinase was the most commonly used thrombolytic (six out of seven cases) and was the only available, 75000 FCFA ~2x the Guaranteed Minimum Inter-Occupational Wage considering its lower price than the latest generations. Coulibaly et al. in Mali in 2015 and Kabore et al. in 2012 in Burkina Faso found even lower rates of thrombolysis use (respectively 0.87% and 4.63%) and with similar reasons, namely long treatment times and the high cost of thrombolytics [15,16]. In western countries, where the management circuit is clearly defined with mobile pre-hospital units, they experience much higher rates of timely reperfusion, reducing management delays [17]. Six patients were medically evacuated to the Shisong Interventional Cardiology Centre in the northwest. Two had salvage angioplasties (after failed thrombolysis), and the other four were deferred after a few days of hospitalization. This low rate of percutaneous transluminal coronary angioplasty is explained by the absence of an interventional cardiology centre in the capital, making primary angioplasties impossible within the first 24 hours of the onset of symptoms. The closure of the Shisong interventional cardiology centre in 2018 and the high price of this procedure add on the difficulties to realize it.

We have also reported a high rate of morbidity (54%) and mortality (13%), although this is similar to the data of other African authors in hospitals of the same category [15,16]. The most frequent complications in the acute phase are hemodynamic disorders (37%) and rhythm disorders (26%), requiring adequate management. However, given the long delay in management since the angina pain felt to the transfer of the patient to the hospital, it is not excluded that this mortality is not reflective  of  reality,  given  that complications such as sudden death, which is frequent in the acute phase of ACS, may occur at home and not be recorded. Therefore, it is essential to improve the current system and propose some basic elements based on the identified problems. (1) Inform the population and health care providers of the immediate steps to take in case of symptoms suggestive of ACS. (2) To improve outpatient management of cardiovascular emergencies. (3) To effectively implement universal health coverage. (4) To provide capacity and equipment to the referral hospitals to improve the existing technical platform. We also have to take the example of other LMICs like India [18].

To summarize, the state of care for ACS in Cameroon is alarming. The results of our study are disquieting and should alert the health authorities to take rapid and effective measures to deal with this ever-increasing condition.

 

Limitations

 

First of all, the small size of the final sample (46), given that we retained only patients with a confirmed diagnosis of acute coronary syndrome based on elements contained in the medical records. Secondly, the lack of information concerning the pre-hospital phase, the intra-hospital management delays not being available, and the long-term survival. All this raises the need for multicentre cohort studies to provide more information and target epidemiological intervention strategies.

 

CONCLUSION

 

The state of care for ACS in Cameroon is alarming. There is an urgent need to improve health care delivery to address the growing burden of cardiovascular diseases in general and acute coronary syndromes in particular.

 

Table 1

Baseline characteristics of patients with acute coronary syndrome in Yaoundé.

 

 

                           CVDs: Cardiovascular Diseases; CAD:  Coronary Artery Diseases.

 

 

Table 2

 Clinical presentation of patients with acute coronary syndrome in Yaoundé.

 

 

GFR: Glomerular Filtration Rate; ACS: Acute Coronary Syndrome; LBBB: Left Bundle Branch Block;

LVEF: Left Ventricular Ejection Fraction.

 

 

Table 3

Management of patients with acute coronary syndrome

 

                            PCI: per cutaneous coronarography; LMWH: Low Molecular Weight Heparin.

 

 

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