Spectrum of cardiovascular diseases at a referral tertiary care hospital in Somalia, Mogadishu: an echocardiographic study

Cardiovascular diseases (CVDs) are the leading cause of death worldwide [1]. The frequency, treatment options, subgroups including congenital heart diseases (CHDs) and rheumatic heart disease (RHD), and outcomes have been well documented in developed countries so far. There are, however, still serious concerns regarding the quality and reliability of available data in low-middle income countries. According to the World Health Organization, CVDs are the second most common cause of overall mortality in Africa. Further supporting this conclusion, 1.2 million people worldwide died from CVDs in 2015 [2]. Of note, CHDs was significantly related to poor cardiovascular outcome among young children and adolescents living in Africa [3]. Meanwhile, difficulties caused by deficiencies in genetic testing and/or advanced imaging methods may cause the diagnosis to be missed or delayed. However, unlike CHDs, which have a relatively similar distribution all over the world, RHD resulting from damage to the heart valves caused by one or more episodes of rheumatic fever is naturally preventable and also another important contributor to morbidity and mortality in low-middle income countries [4]. Furthermore, RHD remains a devastating impact on the health system and is associated with approximately 300,000 deaths globally and loss of > 10 million disability-adjusted life years [5].

Even though echocardiography is an easy-to-use, cost-effective, non-invasive, and reliable ultrasound-based modality, its use in many parts of Africa is still highly limited [6]. Therefore, there is a lack of reliable data on diagnosis, follow-up, treatment, and prevention of CVDs in those regions. Moreover, this drawback is considered to be a crucial and noteworthy challenge in reducing preventable non-communicable diseases in low-middle-income countries. To this end, the present study sought to address the frequency and pattern of CVDs assessed by echocardiographic examinations in Mogadishu, the capital of Somalia.

Out of the study population, 646 (56.7%) were male, the median age was 60 (IQR; 42–70) years and 113 (9.9%) were children. Children were more likely to be female (p = 0.045). Overall, HHD was found to be the most common comorbidity (n:454, 39.8%), followed by VHD (n:395, 34.6%), HFrEF (n:351, 30.8%), and IHD (n:278, 24.4%). RHD was detected in 84 (7.4%) patients. Males tended to have older age, higher rates of diabetes mellitus, HHD, IHD, HFrEF, and DCM, whereas females had more frequent RHD (p < 0.05, for all). While the number of patients with tuberculosis was 202 (17.7%), constrictive pericarditis was diagnosed for various reasons in 9 (0.8%). Detailed demographic characteristics of the study population are listed in Table 1. In subgroup analysis, CHDs were statistically more common in children than in adults (n:102, 90.3% vs n:49, 4.8%, p < 0.001). On the other hand, HHD, IHD, HFrEF, VHD, and DCM were detected at higher rates in adults (p < 0.05, for all) (Additional file 1). The most observed age range among patients with RHD was 16–30 years (n:34, 40.5%), followed by 31–45 years (n:26, 31%), and 0–15 years (n:13, 15.5%) (Fig. 2).

Median EF in the entire population was 60% (IQR: 40–65) and lower in males than in females [55 (35–60) vs 60 (55–65), p < 0.001]. There were 182 (15.9%) subjects with grade II-IV diastolic dysfunction. Overall, 59 (5.2%) subjects had severe valvular pathology (regurgitation/stenosis) in at least one valve, while 336 (29.5%) had mild to moderate valve pathology in at least one valve. Mitral insufficiency (n:541, 47.5%) was detected as the most frequent VHD, followed by aortic insufficiency (n:437, 38.3%), and tricuspid insufficiency (n:264, 23.2%) and mitral valve stenosis (n:39, 3.4%) was the least common VHD (Table 2). On the other hand, 151 (13.2%) patients had CHDs, of whom 23 (15.2%) were cyanotic CHDs. The most frequent CHD was atrial septal defect (ASD) (n:37, 3.2%), followed by ventricular septal defect (VSD) (n:26, 2.3%) and patent ductus arteriosus (PDA) (n:25, 2.2%) (Fig. 3a). ASD was observed to be more common in females, whereas VSD and PDA had a similar frequency across genders (Fig. 3b). When we analyzed the age distribution of participants with CHDs, the most frequent age group was 0–15 years (67.5%), followed by 16–30 years (19.2%) (Table 3).

To the best of our knowledge, this is the first echocardiographic study to comprehensively evaluate such a large cohort of patients in Somalia. Given inadequate healthcare services in Somalia, which is an active war zone, we consider that this study is of high value. In our investigation, HHD was the most frequent comorbidity (39.8%), followed by VHD (34.6%), HFrEF (30.8%), and IHD (24.4%), RHD (7.4%). Additionally, 13.2%, the majority of whom were children, of the study population were diagnosed with CHDs, with the most common being ASD, VSD, and PDA, respectively.

Somalia's total population is estimated at 15.4 million, of whom about 4.5 million are children under the age of 14. Health institutions in Somalia often provide rather limited facilities for individuals with chronic illnesses and those in need of advanced care and unfortunately, no tertiary healthcare centers exist in Mogadishu and surrounding provinces, except for the region where this study was conducted. All these deficiencies prevent timely diagnosis by appropriate detection modalities, increasing the likelihood of poor outcomes in such populations. Moreover, delayed hospital admission, advanced maternal age, high rates of consanguineous marriage, and the presence of many infectious diseases that have not been eradicated nationwide may result in an increased incidence and prevalence of both acquired and congenital heart diseases. Yet, unfortunately, there are very few studies in the literature reporting the risk factors, profile, and echocardiographic characteristics of the African population. For instance, in an echocardiographic study conducted in Nigeria, Ogah et al. [20] determined HHD in 56.7% of the patients. In another echocardiographic study, Raphael et al. [21] evaluated 815 adults and 59 children aged ≤ 15 years and reported that normal echocardiographic findings were detected in only 44% of the patients and that the most common comorbidities were HHD (41%), VHD (18%), coronary artery disease (18%), and peripartum cardiomyopathy (7%) in adults, while CHDs in children (34%). In our study, HHD was also the most common co-morbidity (39.8%), which could be related to the excessive salt consumption by habitants in the region and also to some other factors such as difficult and delayed diagnosis, inadequate medication, and loss to follow-up.

Despite the decrease in the incidence of rheumatic fever/RHD over the last few decades, it remains one of the leading acquired health problems, especially in low-middle income countries [22]. In an investigation on patients with structural and functional valve abnormalities, 24% of the subjects had a valvular abnormality, with the most frequent abnormality being mitral valve insufficiency (59%), and approximately one-third (36%) of the patients were diagnosed with RHD [23]. In the present study, the most frequent valvular abnormality was mitral insufficiency (47.5%), consistent with the former, and a high rate of RHD was diagnosed. Additionally, the relationship between severe VHD and mortality has been demonstrated [24, 25], regardless of the cause, and it is very important to determine the severity of VHD in terms of both follow-up and treatment options. Precisely in this regard, despite not having follow-up records, we have revealed severe valve pathology (insufficiency/stenosis) in 5.2% of the study population with abnormal echocardiographic findings, which is significant data that should be addressed in order to reduce the poor outcome in the region. As noted above, RHD is a very important health problem that needs to be thoroughly addressed in many African countries, including Somalia, mostly due to inadequate healthcare. Also, it is an inevitable requirement to improve healthcare systems and patient follow-up to reduce the incidence of RHD associated with autoimmune pathophysiology.

The prevalence of CHDs is relatively similar worldwide, ranging from 4 to 85 per 1000 births [4, 26, 27]. Although VSD is generally the most common CHDs, studies with a higher frequency of ASD have also been reported, which is compatible with ours [28, 29]. This discordance may be related to the following conditions; (1) inter-regional genetic variation, (2) the overwhelming majority of the participants in our study population is adults and we acknowledge that some small VSDs might close spontaneously with age, and (3) diagnosis by transthoracic echocardiography alone may cause some VSDs to be overlooked. Besides, factors such as excessive use of herbal medicines, alcohol-cigarette consumption, inadequate control of chronic diseases, and the insufficient number of vaccination doses against infectious diseases may be associated with the high prevalence of CHDs in Somalia [30]. Nowadays, with the support of advances in technology and industry, the prevalence of CHDs in adulthood, also called adult congenital heart diseases, has increased steadily in developed countries, whereas in countries with limited resources such as Somalia, only a small proportion of patients with CHDs, particularly in the “complex” subgroup, can reach adulthood, mainly due to deaths from major adverse cardiovascular events and related infections. Similarly, in our study, we concluded that 67.5% of individuals with CHDs were 15 years of age or younger.

As might be predicted, our study intends to raise public awareness rather than introduce innovation or examine a relationship. In this sense, the study will partially fill the data gap in Somalia, which is a war zone. Also, the presence of high rates of HHD, CHDs, and VHD reported in the study sheds light on the points to be improved in the healthcare system so that limited opportunities could be directed to the right areas. Most importantly, the serious lack of accurate diagnosis, treatment, follow-up, and data recording stages in the design and implementation phase have made the current study very difficult and may adversely affect the continuity and planning of other researches in the future. Therefore, we find it clinically crucial to articulate this challenge.

In the present study, we found that HHD was the most common comorbidity (39.8%), followed by VHD (34.6%), HFrEF (30.8%), and IHD (24.4%). In addition, the most frequent valvular disease was mitral insufficiency (47.5%) and the most common CHD was ASD (3.2%). Further comprehensive studies with prospective design are warranted to improve inadequate healthcare services and raise public awareness and cultural knowledge in Somalia, a war zone where financial and healthcare opportunities are highly limited.