Abstract
Rheumatic heart disease is mostly common in low-income or developing parts of the world, such as Sub-Saharan Africa, with a high morbidity and mortality rate. There are few data that are available in Chad on rheumatic heart disease. Our objective was to study the clinical, echocardiographic, therapeutic, and progressive aspects of rheumatic heart disease at the Renaissance University Hospital Center and the National Reference Teaching Hospital in N Djamena, Chad.
This was a prospective, multicenter and observational cohort study, covering a consecutive series of patients consulted and/or hospitalized for rheumatic heart disease, documented by an echocardiogram from January 2015 to January 2021.
Among the 4456 patients consulted and/or hospitalized, 398 cases of rheumatic heart disease (8.9%) were collected, and 364 patients had met the inclusion criteria. The mean age was 31.2 ± 14.4 years, and 193 patients (53%) were female. On admission, heart failure was present in 214 patients (58.8%), ischemic stroke in 10 patients (2.7%) and supraventricular arrhythmias such as atrial fibrillation in 94 patients (25.8%) and atrial flutter in 6 patients (1.6%). Mitral regurgitation was observed in 49.7% (n=181) of cases, aortic regurgitation in 33.2% (n=121), mitral stenosis in 31.3% (n=114), and aortic stenosis in 7.7% (n=28). At least two valvular disorders were combined in 48.4% of cases. A surgical intervention such as a heart valve replacement and/or valvuloplasty was performed in 80 patients (22.2%). At least one rehospitalization was noted in 56.9% of patients. Forty-two of the 150 patients free of heart failure at inclusion (28%) had experienced the first episode of decompensated heart failure during follow-up. On the other hand, in 119 patients (55.6%), it was the second episode of decompensated heart failure. Other progressive complications included atrial fibrillation (13.8%), thromboembolic complications (6.3%), infective endocarditis (6.0%) and prosthetic valve dysfunction (1.4%). Altogether, the mortality rate was 10.4%. It was 9.9% in non-operated patients compared to 12.5% in operated patients (p=0.49).
The present study shows that morbidity and mortality of rheumatic heart disease remain high in our context and often affect children, young adults, and women. Treatment is essentially based on cardiac surgery which is not available in Chad.
Author Contributions
Copyright© 2023
Dangwe Temoua Naibe, et al.
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Introduction
Rheumatic heart disease is mostly common in low-income or developing parts of the world, such as Sub-Saharan Africa, with a high morbidity and mortality, particularly in the population of those aged under 30 This was a prospective, multicenter and observational cohort study, carried out in the cardiology department of the National Reference Teaching Hospital Center, Renaissance University Hospital Center and the Good Samaritan University Hospital in N’Djamena, Chad. A consecutive series of patients were consulted and/or hospitalized for rheumatic heart disease and documented by an echocardiogram from January 2015 to January 2021. Patients aged 15 years and above were úuIgiven an informed consent to participate in the study. The diagnosis of rheumatic heart disease had been confirmed by a doppler echocardiography and the etiology of the rheumatic heart disease was also included. This etiological diagnosis was made considering a history of acute rheumatic fever and/or precordial abnormalities such as the presence of cardiac murmurs, but above all, it was based on the echocardiographic diagnostic criteria established by the World Heart Federation (WHF). This criteria considered the morphology of the valves, the subvalvular apparatus and the doppler ultrasound The variables studied were sociodemographic characteristics, clinical data during patient admission, electrical and echocardiographic data. The various medical and surgical therapies were also recorded. The evolving data concerned the various progressive complications (hemodynamic, rhythmic, thromboembolic, and infectious complications). The mortality study specified the different causes of death. These data relating to each patient were recorded on a previously established data collection sheet. These forms were completed by the doctors. Cardiac surgery, not available in Chad, was made possible for operated patients thanks to the regional program of the international non-governmental organization (NGO) “EMERGENCY” . The NGO runs from 2007 the free of charge Salam Centre for cardiac Surgery based in Khartoum, Sudan threating patients coming from 24 African countries. The evaluation of the severity of valvular lesions, systolic dysfunction of the left ventricle (LVEF ≤ 50%) and dilatation of the left ventricle (DTDLV ≥ 55 mm) was carried out by referring to the recommendations of the European Society of Cardiology ( ESC), American Heart Association (AHA) and American College of Cardiology (ACC) on the management of patients with valvular heart disease Patient consent was obtained. However, a patient’s refusal to participate in the study did not affect their subsequent care. The confidentiality of the data collected was guaranteed.
Results
Among the 4456 patients consulted and/or hospitalized, 398 cases of rheumatic heart disease (8.9%) were collected, while 364 patients percentage met the inclusion criteria. The mean age was 31.2 ± 14.4 years, and 193 patients (53.1%) were females. The 112 patients (30.8%) resided in rural areas and 200 patients (54.9%) that are not educated. The reasons for consultations were dyspnea on exertion (78%), palpitations (69.8%) and precordialgia (40.9%). On admission, heart failure was present in 214 patients (58.8%) and neurological deficit was present in 10 patients (2.7%). Impaired renal function (GFR <60 ml/min) was found in 93 patients (25.5%). On admission electrocardiogram, atrial hypertrophy and left ventricular hypertrophy were found in 42.6% (n=155) and 53.3% (n=194) of cases, respectively. The electrocardiogram also recorded a supraventricular tachycardia disorder such the atrial fibrillation in 25.8% of cases (n=94). Cardiac ultrasound revealed one valvular involvement in 152 patients (41.8%) and two valvular involvements in 58.2% of cases. Mitral valve regurgitation was observed in 49.7% of cases (n=181), aortic valve regurgitation in 33.2% of cases (n=121), mitral valve stenosis in 31.3% of cases (n=114) and aortic valve stenosis in 7.7% of cases (n=28). In 67 patients (18%) mitral valve regurgitation was associated with aortic valve insufficiency and 39 patients (11%) had mitral valve disease. The mean left ventricular end-diastolic diameter (LVEDD) was measured at 54.4 ±13.1 mm and dilatation of the LV (LVEDD >55mm) was noted in 50% of cases. The mean left ventricular ejection fraction (LVEF) was calculated at 59.1 ± 10.6% and a moderate alteration of the LVEF (≤ 45%) was noted in 49 patients (13%). The distribution of valvular diseases and other ultrasound parameters are presented in MVR : Mitral valve regurgitation, MVS : Mitral valve stenosis, AVR : Aortic valve regurgitation, AVS : Aortic valve stenosis, LVEDD : Left Left ventriculaire end-diastolic diameter, LVESD: Left ventricular end-systolic diameter, LVEF: Left ventricular ejection fraction, LATD : Left atrial tranverse diameter, RVSP : Right ventricular systolic pressure. A high proportion of patients were under standard medical treatment for heart failure with 87.1% of patients on loop diuretics, beta blockers (65.7%), aldosterone inhibitors (38.5%) and angiotensin converting enzyme inhibitor or angiotensin II receptor antagonist (42.5%). Oral anticoagulant treatment mainly based on vitamin K antagonists was used in 187 patients (51.4%) and secondary prophylaxis based on penicillin was used in 146 patients (40.1%). Surgical intervention was performed in 80 patients (22%). ( VKA : Vitamine K antagonist After a mean follow-up time of 25.4 ± 13.8 months, 56.9% of patients had been rehospitalized at least once for a cardiovascular cause. During follow-up, the rate of heart failure increased in 256 patients (70,3%) versus 214 patients (58,8%) on admission. On the other hand, in 119 patients (55.6%), there was a recurrence of a decompensated heart failure. Other progressive complications included atrial fibrillation (13.8%), cardiac thromboembolism (6.3%), infective endocarditis (6.0%) and prosthesis dysfunction (1.4%). The mortality rate was 10.4% (n=38). It was 9.9% in non-operated patients (n=28) compared to 12.5% in operated patients (n=10) (p=0.49).
Age (years)
31.2±14.4
15-24
161 (44.2)
25-34
84 (23.1)
35-44
57 (15.7)
45-54
42 (11.5)
≥ 55
20 (5.5)
Gender
Male
171 (47)
Female
193 (53)
Rural residence
112 (30.8)
Educational level
None
200 (54.9)
Primary school
17 (4.7)
Secondary school
81 (22.3)
University graduate
66 (18.1)
History of recurrent angina
66 (18.1)
Symptoms
Dyspnea
284 (78)
Palpitations
254 (60.8)
Precorialgia
149 (40.9)
Cough
110 (30.2)
Heart failure
214 (58.8)
Focal neurologic deficit
10 (2.7)
Left atrial hypertrophy
155 (42.6)
Left ventricular hypertrophy
194 (53.3)
Atrial fibrillation
94 (25.8)
Atrial flutter
7 (1.9)
Focal atrial tachycardia
4 (1.1)
Echocardiographic Parameter
Valvular lesions
All cases
MVR
MVS
AVR
AVS
Total cases
364 (100%)
181(50%)
114(31%)
121(33%)
28(8%)
Systolic function and dimensionc
Mean LVEDD (mm)
54 ± 13
58 ± 12
49 ± 13
59 ± 13
55 ± 13
LVEDD > 55 mm
183 (50%)
112 (62%)
32 (28%)
73 (60%)
13 (46%)
Mean LVESD (mm)
36 ± 12
39 ± 12
32 ± 12
40 ± 12
37 ± 11
LVESD > 45mm
65 (18%)
40 (22%)
10 (9%)
35 (29%)
6 (21%)
Mean LVEF (%)
59 ± 11
59 ± 11
59 ± 9
57 ± 12
54 ± 14
LVEF ≤ 45%
49 (13%)
27 (15%)
10 (9%)
27 (22%)
7 (25%)
Mean LATD (mm)
48±13
51 ± 12
49 ± 12
47 ± 13
40 ± 114
LATD > 50 mm
164 (45%)
89 (49%)
60 (53%)
52 (43%)
9 (32%)
Mean RVSP (mmHg)
52±23
55 ± 21
62 ± 27
48 ± 20
42 ± 20
RVSP > 35 mmHg
250 (69%)
149 (82%)
90 (79%)
85 (70%)
14 (50%)
Valvular regurgitation (mild, moderate, severe)
Mitral valve (%)
181(49,7)
15: 35: 50%
7: 10: 4%
11: 14: 12%
3: 1: 2%
Aortic valve (%)
121(33,2)
25: 21: 10%
16: 12: 4%
38: 41: 21%
2: 7: 4%
Tricuspid valve (%)
90 (24,7)
24: 40: 9%
12: 22: 7%
13: 12: 4%
2: 5: 2%
Oral anticoagulants (VKA)
187 (51.4)
Amiodaron
68 (18.7)
Aldosterone inhibitor
140 (38.5)
Beta blocker
239 (65.7)
Loop diuretics
317 (87.1)
Digoxin
17 (4.7)
Nitrate derivatives
9 (2.5)
Angiotensin converting enzyme inhibitor/ Angiotensin II receptor antagonist
Benzathin penicillin
146 (40.1)
Heart valve surgery
80 (22)
Mechanical prosthesis in valve replacement surgery
62 (17)
Valvular plasty
36 (9.9)
Mean follow-up times (months)
25.4
Cardiology readmission
207 (56.9)
Progressive complications
First episode of heart failure
42 (28)
Recurrence of heart failure
119 (55.6)
Atrial fibrillation
40 (13.8)
Thromboembolic complication
23 (6.3)
Infective endocarditis
22 (6.0)
Prosthesis dysfunction
5 (1.4)
Major bleeding
10 (2.7)
Death
38 (10.4)
Non-operated patients
28 (9.9)
Operated patients
10 (12.5)
Discussion
This prospective, multicenter and observational cohort study allowed us to clarify the epidemiology of rheumatic heart disease in our context. The context is marked by the predominance of poverty, malnutrition, promiscuity, and poor access to education and healthcare structures. These elements are major factors contributing to the occurrence of acute rheumatic fever (ARF) and hence rheumatic heart disease. The prevalence of rheumatic heart disease was relatively high, which was 8.9% of the admissions in our series. This corroborates the work of Naibe et al. This study also made it possible to describe the sociodemographic characteristics of our patients. These were young patients with an average age of 31.2 years, mainly female (53%) and not educated (54.9%). These results were consistent with many previous studies The clinical profile reflected on the evolution of an advanced stage of the disease. Most patients had moderate to severe valvular damage with a LV dilatation in half of the patients and an increase in pulmonary pressures in 69% of the cases. These patients had a very high risk of developing a cardiovascular complication. Heart failure was thus present in 58.8% patients on admission, confirming the crucial role of rheumatic heart disease in the etiopathogenesis of heart failure in Chad and sub-Saharan Africa The management of patients with rheumatic heart disease represents a real challenge for cardiologists in our context, marked by the inaccessibility of reconstructive surgery for valvular heart disease In our study, vitamin K antagonist (VKA) were instituted in 51.4% of patients. Which is lower than the 70% VKA rate reported by Zuhlke et al anticoagulation when indicated in our context is relatively low and maintenance of the International Normalized Ratio (INR) within the target range is poor. Many factors contribute to this, namely the geographical and financial inaccessibility for many patients for the INR biological test (all the laboratories concerned are only located in the capital, N Djamena) and the low level of education of patients regarding the management of their VKA treatment. Strategies to popularize INR examinations as well as better patient education are necessary given the high prevalence of thromboembolic and hemorrhagic complications linked to the use of VKA. In developing countries, rheumatic heart disease remains the major cause of cardiovascular death in children and young adults
Conclusion
The present study shows that morbidity and mortality of rheumatic heart disease remain high in our context and often affect children, young adults and women. Treatment is essentially based on cardiac surgery which is not available in Chad.