Summary
Background
The burden of sudden unexplained death in sub-Saharan Africa is unknown.
Aim
The aim of this study is to establish the epidemiology of sudden cardiac death in Cameroon.
Methods
The Douala sudden unexplained death (Douala-SUD) study is a prospective, multiple-source, community-based surveillance of all cases of unexpected death (< 24 hours from onset of symptoms) occurring in victims aged > 15 years. After approval from institutional boards, all deaths occurring in residents of four areas of Douala city will be checked for circumstances of death and past medical history. Subjects who die naturally will be further investigated. Unexpected death victims will be checked for detailed demographic, clinical, electrocardiographic, echocardiographic and biological records. Autopsy background and genetic analysis (postmortem or in first relatives if the young victim is aged < 40 years) will be performed as far as possible. Finally, the use of cardiopulmonary resuscitation efforts during the timeframe of sudden cardiac arrest will also be evaluated.
Conclusion
The Douala-SUD study will provide comprehensive, contemporary data on the epidemiology of sudden unexplained and cardiac death in sub-Saharan Africa and will help in the development of strategies to prevent and manage cardiac arrest in Cameroon as well as in other sub-Saharan countries.
Résumé
Contexte
Les données sur la fréquence de la mort subite cardiaque en Afrique subsaharienne sont parcellaires et peu robustes.
Objectif
L’objectif de cette étude est d’établir l’épidémiologie de la mort subite cardiaque au Cameroun.
Méthodes
L’étude Douala-SUD est une enquête prospective, multi-site, observationnelle et communautaire, colligeant tous les décès par arrêt cardiaque brutal, inattendu (moins de 24 heures après le début des symptômes), chez les sujets de plus de 15 ans vivant dans 4 aires de santé de certains districts de la ville de Douala. Après approbation des comités d’éthique locaux, tous les décès survenant dans lesdites aires géographiques vont être analysés afin de déterminer leurs circonstances de survenue ainsi que le passé médical des victimes. Tous les décès naturels et inattendus vont être davantage investigués. Leurs données démographiques, cliniques, électrocardiographiques, échocardiographiques et biologiques vont être colligées. Les autopsies cardiaques et l’analyse génétique post-mortem ou des familles de victimes jeunes (< 40 ans) vont être réalisées dans la mesure du possible. Enfin, la propension à réaliser les manœuvres de ressuscitation cardiopulmonaire va également être évaluée.
Conclusion
L’étude Douala-SUD va améliorer la compréhension de l’épidémiologie de la mort subite inexpliquée et cardiaque en Afrique subsaharienne. Par conséquent, elle sera une valeur ajoutée pour le développement des stratégies de politiques de santé publique pour la prévention et la prise en charge des arrêts cardiaques au Cameroun et dans la sous-région d’Afrique subsaharienne.
Background
The overwhelming proportion of sudden death is of cardiac origin . Sudden cardiac death (SCD) is an unexpected death from cardiac causes occurring within a short time period in a person without any prior condition that would appear fatal . Studies assessing risk predictors of SCD have been performed in community-based cohorts and have shown that definitions can be standardized and systematic circumstantial and clinical evidence can be obtained and used to maximize accuracy in identifying the SCD phenotype . Therefore, Fishman et al. developed a unified definition for SCD that can be used to ascertain the SCD phenotype in community-based cohort studies as well as in investigations conducted in the general population. An ‘established SCD’ is an unexpected death without obvious extracardiac cause, occurring with a rapid witnessed collapse or, if unwitnessed, occurring within 1 hour after the onset of symptoms. A ‘probable SCD’ is an unexpected death without obvious extracardiac cause, which occurred within the previous 24 hours. In any situation, the death should not occur in the setting of a prior terminal condition, such as a malignancy that is not in remission or end-stage chronic obstructive lung disease. The term ‘sudden cardiac arrest’ (SCA) is used to describe SCD cases in which specific resuscitation records are available or the individual has survived the cardiac arrest event .
Up to half of all cases of cardiac death are attributable to SCD . It is estimated that more than 3.7 million lives per year are lost to SCD worldwide, including 250,000 to 300,000 in the USA . In the USA and Europe, the annual incidence of SCD ranges from 50 to 100 per 100,000 in the general population . In Asia, the incidence of SCD has been reported to range from 37 to 43 per 100,000 person-years . SCD is mainly caused by coronary artery disease (CAD) . Although cases of SCA due to CAD and other causes have been reported in the black African population , these studies had mainly a cross-sectional, retrospective design ( Table 1 ). The lack of diagnostic tools to rule out inherited arrhythmogenic aetiologies leads to miss diagnosis as well as to misdiagnosis . National public health policies regarding detection, prevention and treatment of non-communicable diseases (NCDs) are inconsistent, mainly due to lack of epidemiological data .
| Case | Main disease | Authors | Title | Country | Type of publication | Journal, year | Size ( n ) |
|---|---|---|---|---|---|---|---|
| 1 | BrS | Bonny et al. | Brugada syndrome in pure black Africans | Ivory Coast, Benin, DR of Congo | Article | Journal of Cardiovascular Electrophysiology, 2008 | 6 |
| 2 | BrS | Ouali et al. | Clinical and electrophysiological profile of Brugada syndrome in the Tunisian population | Tunisia | Article | Pacing and Clinical Electrophysiology, 2011 | 24 |
| 3 | HCM | Hiam et al. | Mort subite du sportif au Sénégal : étude rétrospective sur 8 ans | Senegal | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 5 |
| 4 | IHD | Rotimi et al. | Sudden unexpected death from cardiac causes in Nigerians: a review of 50 autopsied cases | Nigeria | Article | International Journal of Cardiology, 1998 | 50 |
| 5 | Paediatric sample | Arthur et al. | Sudden deaths: cardiac and non-cardiac in children in Accra | Ghana | Article | West African Journal of Medicine, 1995 | 16 |
| 6 | CAD and RHD | Schneider et al. | Causes of sudden death in Addis Ababa, Ethiopia | Ethiopia | Article | Ethiopian Medical Journal, 2001 | 63 |
| 7 | Unknown | Houenassi et al. | Aspect epidémiologiques de la mort subite dans la ville de Parakou | Benin | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 23 |
| 8 | Multiple causes (CAD, DCM, LQTS, RHD) | Talle et al. | SCD in sub-Saharan Africa: a 12-month review in the University of Maiduguri Teaching Hospital, Nigeria | Nigeria | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 17 |
| 9 | Multiple causes (DCM, CAD, RHD) | Thiam et al. | La mort subite cardio-vasculaire au Sénégal : étude rétrospective sur 7 ans | Senegal | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 235 |
| 10 | LQTS | Leye et al. | QT long congenital syncopal évocateur de syndrome de Jervell Lange Nielsen | Senegal | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 1 |
| 11 | NCCM | Kamotho et al. | A rare presentation of non-compaction cardiomyopathy in Kenya | Kenya | Abstract | PASCAR Conference, Dakar; 15–20 May, 2013 | 1 |
| 12 | ARVD/C | Kouakam | Syncope in a black African with arrhythmogenic right ventricular dysplasia | Cameroon | Unpublished data | Unpublished data | 1 |
| 13 | Hypertensive CM (mainly) | Akinwusi et al. | Pattern of sudden death at Ladoke Akintola University of Technology Teaching Hospital, Osogbo, South West Nigeria | Nigeria | Article | Vascular Health and Risk Management, 2013 | ∼16 |
The Douala sudden unexplained death (Douala-SUD) study is a collaborative study that aims to collect comprehensive data on the prevalence and incidence of unexplained premature deaths in Cameroon, disease and patient characteristics, mechanisms of cardiac arrest and survival rate in the setting of underuse of cardiopulmonary resuscitation programmes.
Methods
Study design
Study population
This is a prospective, multiple-source, community-based, cohort surveillance of all cases of sudden and unexpected death in the city of Douala.
Objectives
The specific objectives of the registry are as follows:
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to estimate the incidence of SCD in the city of Douala;
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to characterize all unexplained premature deaths;
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to evaluate the extent of the use of cardiopulmonary resuscitation efforts in this remote community area;
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to evaluate outcomes of survivors of SCA.
Study eligibility
To be eligible, subjects must be a resident of the administrative area (district) included in the study registry and the district must have an updated population census. Subjects can be included if they are a person who has experienced an unexpected sudden natural death or a victim of cardiac arrest who has been resuscitated. Subjects will be excluded if they are aged ≤ 15 years or if consent has been refused by the subject (if resuscitated) or by the family.
Data collection
Run-in period
In eight of 57 health areas constituting all six Health Districts of the city of Douala, investigators conducted a pilot survey to determine the trend of sudden death and evaluate the adherence of each health area team to the effective collection of data during a 6-month run-in period. The choice of these eight health areas was based on the selection of areas with > 30,000 inhabitants as the first step and random sampling among them as the second step.
Main study period
Two health areas were excluded for inaccurate data collection and two others were randomly disqualified as we had previously decided to conduct the survey in fewer than four areas. The mode of randomization aimed to include no more than one health area per health district. Finally, investigators retained four health areas representing four of six health districts of Douala ( Table 2 ). Thus, the sampling of 240,384 inhabitants will be monitored prospectively. All administrative staff and the community healthcare committee – the so-called ‘comité de santé’ (COSA; Table 2 ) – of each health area will be a key component of the research team, helping to identify each case of death in the area of concern.
