Introduction

The impacts of non-communicable diseases (NCDs) are particularly devastating in poor and vulnerable populations [1]. NCDs currently cause more deaths than all other causes combined and is projected to increase from 38 million in 2012 to 52 million by 2030 [2]. Nearly three quarters of all NCD deaths occur in low- and middle-income countries. NCD deaths will increase by 17% over the next ten years and the greatest increase will be seen in the African region [2]. In Ethiopia, the recent NCD deaths are estimated at around 42% with cardiovascular diseases are the predominant cause of morbidity and mortality [3–5].

Cardiovascular disease remains the leading NCDs related cause of death in the world. Approximately 80% of all cardiovascular-related deaths occur in low and middle income countries and at a younger age in comparison to high-income countries [6]. Africa is home to for over 1 billion people, and is a major contributor to the global burden of CVD [7,8]. In 2013, an estimated 1 million deaths were attributable to CVD in sub-Saharan Africa alone [7,9]. CVD-related deaths contributed to 38% of all non-communicable disease-related deaths in Africa, reflecting the growing threat of both non-communicable disease and CVD [9]. The understanding of adults about CVD and its risk factors including hypertension and diabetes is low in developing countries. More than half of adults in sub-Saharan Africa have poor knowledge of CVD [10,11]. Similarly, in Ethiopia the knowledge of cardiovascular risk factors among CVD patients was unsatisfactory, and about half of the patients have suboptimal knowledge [12]. In another study, 52% of Ethiopian hypertensive patients on follow up have poor basic knowledge of hypertension, and about 60% of them have poor practice towards control of hypertension [13]. Patient noncompliance is also one of the most difficult challenges in the healthcare sector and therefore, it is vital to enhance patients’ awareness and knowledge about the complications and benefits of cardiovascular medications [14].

A cardiovascular spectrum study in Addis Ababa has revealed the five most common cardiovascular diseases such as valvular heart disease (62%), hypertension (14.7%), cerebrovascular disease (11.5%), congenital heart disease (8.5%), and ischemic heart disease (IHD) (6.8%) [15]. Another outpatient CVD spectrum study also demonstrated that RHD was the common cause of cardiovascular disease followed by HHD and cardiomyopathy [16]. Similar study in the cardiac follow up clinic of Jimma Specialized Hospital showed that rheumatic heart disease was the leading cause of cardiac illness (32.8%), followed by hypertensive heart disease (24.2%), cardiomyopathy(20.2%), arrhythmia(13.5%) and cor-pulmonale(3.8%) [17]. However, there is an increasing trend of hypertensive heart disease in the subsequent periods replacing the place of valvular heart diseases.

A recent outpatient study conducted in Northern Ethiopia revealed that Hypertensive heart disease was the predominant etiologic diagnosis of cardiovascular disease followed by rheumatic heart disease [18]. In this study, hypertensive heart disease has markedly surpassed rheumatic heart disease as the leading heart disease which might be due to the high proportion of hypertension (62.3%) among the CVD patients in the area [18]. In another African studies hypertension was also the main causes of heart failure (21.3%), followed by rheumatic heart diseases (20.1%), cardiomyopathy(16.8%), coronary artery disease(10%), and congenital heart disease (9.8%) [19]. Different studies have demonstrated that much of the population risk of CVD is attributable to modifiable traditional risk factors, including hypertension, diabetes mellitus, dyslipidemia, smoking, lack of physical activity, and psychosocial factors [6,20]. These risk factors account for 61% of CVD deaths globally and alleviating exposure to these risk factors would improve global life expectancy by almost 5 years [21]. In Ethiopia, there is a paucity of data regarding CVDs and their risk factors, making accurate estimation of burden in terms of the morbidity and mortality of CVDs extremely difficult. This study will therefore provide relevant data regarding the recent magnitude as well as spectrum of cardiovascular admission and its outcome among medical patients in St. Paul specialized hospital, Addis Ababa.

Methods

Results

Socio-demographic characteristics of the study population

From the annual medical admissions of 1,165 patients to st. Paul Hospital Millennium Medical College from 1^st of January 2010 up to 1^st of January 2021, the total cardiovascular admissions constituted 30.3%(353). Majority of the study subjects were females (60%(213)). Addis Ababa together with Oromia regional state constituted 90% of total cardiovascular admissions to St. Paul Hospital Millennium Medical College during the study period (Table 1). The minimum age among the cardiovascular admissions was 15years and the maximum age was 86years with the mean and median ages were 48.9 and 50years, respectively. The overall cardiovascular illness increased almost steeply with increasing age(p = 0.001). However, further disease stratification showed that Rheumatic valvular heart diseases(CRVHD) and vascular diseases including deep vein thrombosis (DVT), pulmonary thromboembolism (PTE) and cerebral venous thrombosis (CVT) were more common in the younger age and proportionally decreased as age advances(p = 0.001) (Fig 1).

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 1. The associations of major cardiovascular diseases with increasing age.

p<0.001.

https://doi.org/10.1371/journal.pone.0267527.g001

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. Socio-demographic characteristics of cardiovascular admissions.

https://doi.org/10.1371/journal.pone.0267527.t001

Spectrum of cardiovascular diseases and associated risk factors.

The spectrum of major cardiovascular diseases was scrutinized according to the ICD-10 classification of diseases [22] and most of the patients had two or more cardiovascular diagnoses. From all cardiovascular admissions, about 60%(212) of patients had advanced congestive heart failure (NYHA class III and class IV) (Table 2). The advanced congestive heart failure (CHF) had multiple underlying etiologies, and also multiple precipitating factors including hypertension(35%(74)), lung infection(pneumonia) (34%(72)), drug discontinuation (25.5%(54)), and arrhythmia (23.6%(50)) predominantly atrial fibrillation with fast ventricular response(Afib with FVR).

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. Spectrum of major cardiovascular Diseases in St. Paul Hospital Millennium Medical College.

https://doi.org/10.1371/journal.pone.0267527.t002

Hypertensive heart disease (HHD) constituted for 41.4%(146) of the total CVD diagnosis as well as the leading etiologic cause of advanced heart failure. Its prevalence increased with increasing age (p<0.001). HHD was more predominant among urban residents than rural ones ((63%(92) Vs 37%(54), p = 0.001)). Valvular heart diseases (both rheumatic and degenerative valvular heart diseases combined) accounted for about 34.5% of all advanced cardiac failure cases and 20.5% (73) of all the cardiovascular admissions as shown in the Table 2.

Chronic rheumatic valvular heart diseases(CRVHD) was more predominant in patients coming from outside of Addis Ababa compared to residents of Addis Ababa(82.8%(53) Vs 17.1%(11)(p = 0.001). Echocardiography proven isolated MS and MS with MR constituted 26%(19) and 27.5%(20) of all valvular heart diseases, respectively. The proportion of degenerative valvular heart diseases increased with advancing ages (p = 0.01) whereas rheumatic heart diseases decreased as age increased (p = 0.01). Ischemic heart disease (IHD) accounted for 12.2%(43) of all CVD admissions. Its prevalence has significantly increased with age and males had higher proportion than females(p = 0.001). IHD was more common in residents of Addis Ababa than those who came from out of Addis Ababa but the difference was not significant (p = 0.2). IHD was significantly associated with hypertension and diabetes (p = 0.001, each). From all IHD patients, 90.24% had hypertension with 13.5% had good hypertension control, 59.5% had poor hypertension control, and 27% were newly diagnosed hypertension. Similarly, 41.5% of IHD patients had diabetes mellitus with 41.5% had good glycemic control, 35.3% had poor glycemic control and 17.6% were newly diagnosed T2DM. About 11%(40) of CVD admissions had pulmonary heart disease(PHD) with over 42% of them were attributed to COPD and the remaining were due to chronic PTE and post-TB fibrosis. PHD was more common in patients who came from Addis Ababa than those coming outside of Addis Ababa but the difference was not significant (p = 0.053). Females constituted over two-third of patients diagnosed with dilated cardiomyopathy and peripartal cardiomyopathy accounted for 26.5%(p = 0.01).

Vascular diseases (VasD) were the most common cause of cardiovascular diseases next to CHF and HHD. It accounted for about a quarter of cardiovascular diagnosis and females constituted about two-third of the cases. DVT was the leading vascular cause accounting for 44%(37) followed by PTE of about 30%(25). Peripheral arterial disease (PAD) and cerebral venous thrombosis(CVT) accounted for 15.5%(13) and 9.5%(8) of vascular disease admissions, respectively. Pregnancy and related conditions such as caesarian section and puerperium (30.6%(26)); major surgery and prolonged immobilization for medical illnesses(28.2%(24)); and active cancers(11.7%(10)) were the major risk factors of venous thrombo-embolism(VTE). Hypertension and diabetes were significantly associated with PAD(p = 0.001, each). Hypertension was documented as a risk factor in about 85% of patients with PAD followed by diabetes mellitus and chronic kidney disease, each of which were implicated as a risk factor in 25% of cases of PAD. The cumulative rate of vascular diseases have significantly decreased as the age of the patients increased(p = 0.01) (Fig 1).

Cerebrovascular accident (stroke) accounted for about 20%(71) of total annual cardiovascular admission with hemorrhagic stroke constituted about 17% and ischemic stroke for the remaining 83% of the total stroke patients. Of all ischemic stroke, cardioembolic stroke accounted for 32.2%. From all the atherothrombotic ischemic stroke groups, 7.5% had hemorrhagic transformation during the course of hospital stay. Stroke was predominant in residents of Addis Ababa than those who came outside of Addis Ababa although the difference was not statistically significant (p = 0.07) but it increased with increasing age(p = 0.001) (Fig 1). There was no variation of stroke distribution between males and females (male = 45% and female = 55%, p = 0.09). Hypertension was the leading risk factor for stroke, followed by atrial fibrillation (Fig 2). All patients with hemorrhagic stroke had hypertension and 75% of them had long standing uncontrolled hypertension whereas the remaining 25% had newly diagnosed hypertension. Similarly, 97.5% of atherothrombotic ischemic stroke(non-cardio-embolic) patients had hypertension with 61.5% of them had uncontrolled hypertension whereas about 38% had newly diagnosed hypertension after the current presentation. About one-third of atherothrombotic ischemic stroke patients had diabetes. Atrial fibrillation accounted for 73.7% of cardioembolic stroke admissions with 71.5% of CRVHD patients and 60% of DCMP patients had atrial fibrillation.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 2. Major risk factors of stroke among admitted patients in St Paul Hospital Millennium Medical College.

https://doi.org/10.1371/journal.pone.0267527.g002

Hypertension and diabetes control among the cardiovascular admissions.

Of all the 353 annual cardiovascular admissions, 47.6%(168) patients had history of hypertension. Hypertension was prevalent in patients from Addis Ababa than patients who came outside of Addis Ababa ((63.7%(107) Vs 36.3%(61), p = 0.001)). The minimum duration of hypertension ranged from newly diagnosed hypertension up to the maximum of 30 years. Only 20% of patients had good hypertension control (BP<140/90mmHg) with adherence to the medications and have frequent follow up whereas 46.6% of patients had poor hypertension control (BP≥140/90mmHg) who were either not adherent to or discontinued their pharmacologic therapy by themselves. About 35% of hypertensive patients were newly diagnosed during their current admission. The control of hypertension in patients from Addis Ababa was significantly better than patients coming outside of Addis Ababa (p = 0.001). The proportion of diabetes mellitus(DM) among the cardiovascular admissions was 17.6%(62) and significantly prevalent in patients from Addis Ababa than those out of Addis Abbaba ((74.1%(46) Vs 25.8%(16), p = 0.001)). The duration of DM history ranged from newly diagnosed DM up to 25 years. About 40% of DM patients had ’’good’’ DM control with mean FBS≤130mg/dl and/or A1C<7% whereas 46.8% had ’’poor’’ DM control (mean FBS>130mg/dl and/or A1C>7%). The control of diabetes in patients from Addis Ababa was significantly better than those coming outside of Addis Ababa (p = 0.001).

Outcomes of cardiovascular disease admissions

Among patients with CVD admissions, the minimum hospital stay was one day and the maximum was 80 days with the average hospital stay was 12days. About 57%(201) of cardiovascular admissions were discharged from the hospital with improvement, 10%(36) were discharged with the same condition(most were stroke patients with dense hemiplegia and also stage-D CHF patients), and 4.5% (16) were left against medical advice. The in-hospital mortality rate among the cardiovascular admission was 24.3%(86) with the predominated immediate cause of death being sepsis with septic shock(25.6%) followed by fatal arrhythmia (19.8%), brain herniation (15%), massive PTE (14%), and cardiogenic shock (11.6%) (Table 3).

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 3. Major causes of death among cardiovascular admissions in St Paul Hospital.

https://doi.org/10.1371/journal.pone.0267527.t003

Discussion

The epidemic of cardiovascular disease (CVD) is a global phenomenon, and the magnitude of its burden is alarmingly increasing in the developing world including Ethiopia [6]. In the current study which involved all the annual medical admissions of 1,165 patients at St. Paul Hospital Millennium Medical College, the total cardiovascular admission constituted 30.3%. The present burden of cardiovascular causes of medical admission was in agreement with the previous studies [25]. However, the previous studies considered hypertension as a separate exclusive CVD diagnosis but in this study hypertension was considered as a CVD risk factor and hypertensive heart disease was an exclusive diagnosis as per the International Disease Classification(ICD-10) [22]. The present finding is also in tandem with the cardiovascular admission of 31% among all medical admission in the Nigerian Teaching hospital [26]. However, the current rate of CVD admission is much greater than 17.5% of CVD admission in Asella Referal Hospital [27]. This difference might be due to large proportion of urban residence in our study dominated by cardiovascular risk factors including hypertension and diabetes unlike the former area where infectious causes of admission accounted for close to 50% [27].

Most of the CVD patients (60%) were admitted with the clinical diagnosis of advanced congestive heart failure (CHF) (NYHA class III and IV). This high rate of CHF in the current study is in agreement with other Ethiopian studies [25,28]. Surprisingly, apart from hypertension and pneumonia, over a quarter of CHF patients had associated history of drug discontinuation as a precipitating factor eventually worsening their heart failure condition. Therefore, healthcare providers should also equally focus on health education including adherence to the medical therapy in addition to prescribing the pharmacologic agents based on the appropriate diagnosis.

Hypertensive heart disease (HHD) was the second predominant diagnosis constituting for 41% of overall cardiovascular admission and also the leading cause of heart failure followed by rheumatic valvular heart disease(RVHD) which constituted for about 18% of all CVD. In most of the previous studies involving both inpatient and outpatient follow up clinics, VHD was considered to be the leading cause of CVD in general and cardiac diseases in particular [17,18,25,27–29]. This increased burden of HHD shown in the current study, however, is consistent with other recent studies in Ethiopia [18]. The high proportion of hypertension (about 48%) among our CVD patients also supports the high rate of HHD. Compared to rural dwellers, HHD in the current study was predominant in urban residents(p = 0.01). It may be partly due to an increasing urbanization and westernization of diet in the present metropolitan area coupled with better health care availability allaying the risk factors for rheumatic valvular heart disease (RVHD). RVHD in the current study is dominant in patients coming from rural area than the residents of Addis Ababa(p = 0.001). Rural predominance of RVHD is consistent with previous studies [16–18]. This could partly be justified by the early treatment of upper respiratory tract infection and better access to health care in urban residents. RVHD in the present study was also predominant in females (p = 0.001) and it is in agreement with previous studies [16,17]. Ischemic heart disease (IHD) and dilated cardiomyopathy(DCMP) were other causes of cardiac diseases constituting for 12.2%, and 9.6% of annual CVD admissions, respectively and their burden increased with increasing age(p = 0.01). These findings are in agreement with other national studies [16,18,28]. The tall of ischemic heart disease is significant when the current rate of 12,200 per 100,000 is compared with the data of 7,400 per 100,000 in 2014 [15]. The risk of IHD was associated with Hypertension and Diabetes mellitus (p = 0.001, each) and is in agreement with similar studies [15].

Cerebrovascular accident (CVA) or stroke accounted for 20% of annual CVD admissions with ischemic stroke being the predominant sub-type(83%), and hemorrhagic stroke constituted the remaining 17%. This finding is consistent with the well-established global data and some of Ethiopian studies where Ischemic stroke is the dominant sub-type [15,30–32]. However, the current finding is not in agreement with some of the Ethiopian data in which hemorrhagic stroke was reported to be the dominant subtype [33–35]. The exaggerated hemorrhagic stroke compared to ischemic stroke which was reported in a number of studies in Ethiopia mandates further scrutiny. In this study, hypertension was present in 74% of patients with stroke. All hemorrhagic stroke patients had hypertension and 75% of them had long standing uncontrolled hypertension whereas the remaining 25% had newly diagnosed hypertension. This finding is in agreement with other similar studies [30,33,36]. Since one-third of our ischemic stroke patients had pre-existing atrial fibrillation (AFib) and AFib significantly raises the likelihood of stroke, effective preventive therapy is critical and should be one of the key management priorities [14]. Furthermore, 97.5% of atherothrombotic(non-cardioembolic) ischemic stroke patients had hypertension as a major risk factor where 61% of them had uncontrolled hypertension and 38% of them had newly diagnosed or untreated hypertension. This finding is also in conformity with other studies [30,33,36]. Therefore, poor screening, poor follow up and adherence against CVD risk factors including hypertension, makes it imperative to re-evaluate our management practices, so as to establish a consolidated approach involving the relevant stakeholders. For countries of poor economy including ours, prevention is much cheaper and profitable than the complex and costly managements of the subsequent CVD diseases and their complications. Therefore, timely screening for the cardiovascular risk factors as well as early identification of complications utilizing various approaches including technology of telemedicine could be an efficient, and cost effective method [37].

Hypertension, in the current study, was found to be the dominant risk factor for cardiovascular diseases where about 48% of CVD patients had hypertension. However, this finding is higher than some of the previous reports of hypertension burden among the CVD patients in Ethiopia [15,16,17,25,38] but much lower than the 62% as shown in the study conducted in Gondar Referral Hospital [18]. Our finding is also consistent with the overall increasing trends of atherosclerotic CVD burden in the recent decades with hypertension being a significant risk factor [18,39]. The worrisome finding was that only 20% of our patients with longstanding hypertension had good hypertension control whereas about 47% of patients had poor hypertension control who were either not adherent to or discontinued their antihypertensive therapies by themselves. Furthermore, 35.2% of hypertensive patients were newly diagnosed or told to have raised blood pressure in the past but not on therapy or follow up. This poor hypertension control is consistent with other studies [40,41] and warrants timely intervention. Similarly, from all CVD patients with long standing diabetes mellitus, only 40.3% had good glycemic control whereas 46.8% had poor glycemic control and poor follow up. About 13% of diabetes was newly diagnosed type-2 diabetes after they were admitted for the current cardiovascular illness. These findings are consistent with other studies in Ethiopia [42,43] but much better than the 20% of good glycemic control at Tikur Anbessa Specialized Hospital [24]. Despite the rising cost of newer cardiovascular drugs are challenging the drug adherence in the settings with poor economies, some of the older, cheaper and effective agents can still be easily available to serve as a backbone and drug of first choice [44] so as to improve the drug adherence.

Vascular diseases including deep venous thrombosis (DVT), pulmonary thromboembolism (PTE), peripheral arterial disease (PAD), and cerebral venous thrombosis (CVT) were common in the present study area and all together constituted about 24% of all the annual CVD admissions. DVT was the leading cause of vascular admission (44%), followed by PTE(30%), PAD(15.5%) and CVT (9.5%), respectively. The current vascular disease burden is much higher than the previous cardiovascular spectrum studies [15,16,18] which involved the outpatients, unlike the admitted patients who have higher risk factors [45,46]. Major risk contributors of venous thromboembolism (VTE) were pregnancy and its related conditions such as puerperium and cesarean section (30.6%), major surgery and prolonged immobilization for medical illnesses (28.2%), and active cancers (11.7%). The higher burden of DVT, younger age and female predominance, major risks (pregnancy and puerperium, prolonged immobility and malignancy) documented in the current study are consistent with previous studies in Addis Ababa Hospitals [45,46]. The high rate of VTE, including massive PTE as one of the major immediate cause of death (Table 3), may be partly due to lack of comprehensive guideline based venous thromboembolism (VTE) prophylaxis consistent with the degree of risk factors. The Ethiopian custom of prolonged bed rest (immobility) during puerperium might have also exacerbated the existing procoagulant risks. Hypertension was a risk factor in about 85% of patients with PAD followed by diabetes mellitus (25%). This is consistent with the association of uncontrolled hypertension and diabetes with atherosclerotic CVD diseases including PAD [38]. Therefore, such findings mandate comprehensive approach to develop proper CVD risk assessment and disease control.

The mean duration of hospital stay in the current study was 12days with the minimum hospital stay was one day and the maximum was 80 days. This result is comparable with the average of 12.33days of hospital stay for medical admission [25] and 11.14days for stroke admissions at St. Paul hospital [34] but less than the 14.4days of total hospital stay at Asella referral hospital [27]. There were 57% of CVD patients discharged with improvement and in-hospital mortality rate was 24.3%. These findings are comparable to the previous St. Paul hospital reports of in-hospital death rate of 24.2% and discharge rate with improvement of 66% among the medical admissions [25]. Despite the current mortality rate is lower than the 25% documented among the cardiovascular admissions in Addis Ababa [28] and the 30% mortality rate among stroke admissions in St. Paul Teaching hospital [34], it is higher than the 12.2% among cardiovascular admissions in Nigeria [26]. Sepsis with septic shock was the leading immediate cause of death in about a quarter of deaths among CVD admissions, followed by fatal arrhythmia, brain herniation, massive PTE and cardiogenic shock in 20%, 15% and 14%, respectively. Consistent with our study, infectious disease was also the leading cause of mortality among medical admissions studied previously [25,27]. Therefore, comprehensive work is needed to improve impatient medical care in addition to CVD risk assessment, and disease control.

Acknowledgments

The author acknowledges St Paul Hospital Millennium Medical College for provision of some financial support. The author is also grateful to all data collectors for their scientific contribution and data clerks for their supported to access the patient charts.