CHAPTER 13
Hypertensive heart failure
Dike Bevis Ojji1, Mahmoud Sani2, Anastase Dzudie3, and Okechukwu Samuel Ogah4
1 University of Abuja Teaching Hospital, Abuja, Nigeria
2 Bayero University Kano/Aminu Kano Teaching Hospital, Kano, Nigeria
3 Hospital General de Douala, Douala, Littoral, Cameroon
4 University College Hospital, Ibadan, Oyo, Nigeria
13.0 Introduction
In this chapter we describe three different studies (one from Soweto, South Africa, and the other two from Nigeria) examining the clinical spectrum and consequences of hypertension and hypertensive HF in the African context. As already outlined in Chapter 4, given elevated BP levels observed across the continent, hypertension may well pose the largest threat to the future health of the African population as it effectively combats infectious disease and increases its overall economic wealth. These studies (with comparison across two study findings) provide an important insight into the contemporary and likely future burden of hypertensive HF in sub-Saharan Africa.
13.1 Clinical consequences and challenges of hypertension in urban-dwelling black Africans
Stewart S, Libhaber E, Carrington MJ, Damasceno A, Abbasi H, Hansen C, Wilkinson D, Silwa K. The clinical consequences and challenges of hypertension in urban-dwelling black Africans: Insights from the Heart of Soweto Study. International Journal of Cardiology 2011; 146(1):22–27. [79]
13.1.1 Study background
At the time of this study (derived from the Heart of Soweto Study described in more detail in Chapter 6) it was noted that although data describing the broad pattern of hypertension in LMIC and sub-Saharan Africa are readily available [80], there are few studies examining the clinical consequences of undiagnosed/untreated and/or controlled hypertension in this context. In order to minimize the emergence of noncommunicable forms of CVD, it is critical to understand the consequences of undetected and untreated hypertension in vulnerable communities in urban sub-Saharan Africa. During 2006, the clinical spectrum of CVD and its risk factors were reported in prevalent and incident cases of heart disease as part of the Heart of Soweto Study [22,81] (see Chapter 6 for full details). In patients of African ancestry, hypertension was diagnosed in more than half of the patients and was frequently associated with advanced forms of heart disease. Overall, hypertension was revealed as the most common diagnosis in the cohort [30].
13.1.2 Study aims
The primary aim of this study was to examine the clinical consequences of hypertension as manifested in advanced presentations of hypertensive heart disease in the setting of an urban African population in whom both epidemiological transition and a poor awareness and response to noncommunicable forms of heart disease might play an important role in generating a substantial health burden.
13.1.3 Study methods
13.1.3.1 Patient enrollment
The Heart of Soweto Study methods have been described in greater detail in Chapter 6. For these analyses, all de novo presentations to the Cardiology Unit of the Chris Hani Baragwanath Hospital in Soweto in the year 2006 that were of African ancestry and clinically diagnosed with hypertension were included. Of the total of 897 de novo patients with hypertension, 761 (84.8%) were of African ancestry and were included in the study [22]. Included patients comprised emergency patients who were referred directly to the Cardiology Unit with recognized CVD, those referred externally from local primary care clinics for more definitive examination and treatment, and those referred internally to the Cardiology Unit on an inpatient and outpatient basis. The clinical spectrum of study patients, therefore, ranged from those with uncomplicated hypertension being treated with combination antihypertensive therapy to first-ever diagnosed patients with advanced hypertensive heart disease yet to receive definitive treatment.
13.1.4 Study findings
13.1.4.1 Demographic and clinical characteristics
The study cohort included 482 (63.3%) women who were of a similar age profile (typically middle aged) to their male counterparts (mean age of 58.5 ± 14.9 years versus 58.0 ± 15.6 years). Overall, 168 (22.1%) patients reported a family history of CVD, with more women reporting the risk factor than men (OR 1.63, 95% CI 1.20–2.23: p = 0.001). Men were more likely to have a cardiovascular risk factor other than hypertension (OR 1.86, 95% CI 1.29–2.69: p = 0.001) and to smoke cigarettes (OR 4.72, 95% CI 3.44–6.45: p < 0.0001). However, women were more likely to be obese (OR 2.66, 95% CI 1.83–3.86: p < 0.001). As shown in Figure 13.1, HF was found to be more common among men (n = 166 [59.5%] versus n = 244 [50.1%]; p = 0.018), as well as renal disease (n = 30 [10.8%] versus n = 39 [8.1%]; p = 0.001). Overall there were minor sex differences with regard to structural valve disease, CAD, stroke, diabetes, and HIV infection.
Figure 13.1 Comorbidities among study participants according to sex.
13.1.4.2 BP profile and management
BP profiles varied according to stage of treatment and presentation status. In total, 350 (46%) patients had a BP of ≥140/90 mm Hg and were considered to be hypertensive, while there was a weak association between systolic BP and age which was slightly stronger in men (p < 0.001) than in women (p = 0.042). Patients without progressive CVD presented with a significantly lower systolic (135 ± 27 versus 144 ± 28 mm Hg; p < 0.0001) but not diastolic BP. When presenting to the Cardiology Unit, it was found that 473 (62%) patients were currently on active antihypertensive therapy; the most commonly prescribed antihypertensive agents were calcium channel antagonists (20%), aldosterone inhibitor (20%), beta blockers (25%), ACE inhibitors (39%), and loop diuretics (49%). Overall, 384 (81.2%) patients were prescribed combination therapy, and 211 (44.6%) prescribed triple therapy. Combination therapy was associated with lower systolic BP (133 ± 29 versus 140 ± 28 mm Hg: p = 0.034) and diastolic BP (74 ± 17 versus 78 ± 16 mm Hg; p = 0.052). Those prescribed an aldosterone inhibitor (systolic BP 133 ± 24 versus 142 ± 30 mm Hg) or an ACE inhibitor (134 ± 27 versus 141 ± 29/74 ± 16 versus 79 ± 16 mm Hg: p < 0.001) had significantly lower BP profiles.
13.1.4.3 Hypertensive HF and other advanced forms of heart disease
Overall, 494 (65%) patients presented with progressive cardiovascular forms comprising a combination of stroke (3.3%), CAD (6.2%), renal disease (9.1%), anemia (11%), and most strikingly, hypertensive HF (54%). Echocardiography demonstrated that an additional 98 (13%) patients had abnormal valvular function. Overall, more than half (59%) of these were attributable to underlying structural valve disease. In addition, 258 (41%) patients displayed evidence of mildly impaired renal dysfunction and 150 (24%) had moderate to severe renal dysfunction indicative of progressive end organ damage. Although women were more likely than men to present with clinical symptoms, they were less likely to be diagnosed with renal disease (OR 0.47, 95% CI 0.30–0.73: p = 0.001), and/or to present with HF (OR 0.85, 95% CI 0.75–0.97: p = 0.018). Men were more likely to present with abnormal valvular function (OR 1.42, 95% CI 1.00–2.03: p = 0.046).
13.1.4.4 Cardiac function
In total, 103 (24%) patients presented with evidence of RHF on ECG, 163 (24%) with diastolic dysfunction, 158 (24%) with moderate to severe systolic dysfunction, and 264 (39%) with LVH. Men displayed a significantly lower LVEF and larger LV dimensions, which increased their chance of presenting with impaired systolic function (OR 2.13, 95% CI 1.50–3.00; p < 0.0001). Although there were minimal sex differences in LVH, women were less likely to present with any form of 12-lead ECG change (OR 0.57, 95% CI 0.36–0.88). The likelihood of presenting with concurrent systolic dysfunction and hypertension increased as patients grew older, in men, in those who smoked cigarettes, and in those with an elevated diastolic BP and heart rate. However, the likelihood of presenting with concurrent systolic dysfunction decreased with increasing systolic BP.
13.1.5 Study interpretation
This study prospectively analyzed the characteristics and consequences of hypertension in 761 urban-dwelling individuals of African ancestry presenting to a tertiary care center during 2006 [22]. In total, approximately 40% of patients presented with LVH and approximately 60% had previously undiagnosed heart and vascular disease [80]. These striking results were unfortunately consistent with the disturbingly low detection, treatment, and control levels of hypertension in Soweto and other parts of sub-Saharan Africa [80]. The findings confirm the importance of focusing on hypertension as a major contributor to avoidable noncommunicable heart disease—particularly in the form of hypertensive HF. Despite not providing a complete understanding of the history of hypertension leading to progressive heart disease in this African community, these data offer important insights for prevention strategies. The early signs of a hypertensive heart disease epidemic have been uncovered and will result in an escalating burden if primary and secondary prevention is not applied on a systematic basis. Fortunately, hypertension is readily detectable and can be controlled with inexpensive treatments [82,83]. Regardless of the population studied, hypertension is crucial to the subsequent vulnerability to and development of HF (particularly in the clinical context of LVH), although the pathways to HF are many and varied; further, the progression from concentric LVH to HF has not yet been recorded in Africa. Overall, 54% of the total study population presented with low to normal BP and advanced forms of heart disease. Consistent with previous reports [84], reasonably low levels of diagnosed anemia and renal disease were revealed. However, more than half of the patients had a combination of mild (41%) or moderate-to-severe (24%) renal dysfunction, and this was undoubtedly linked to their hypertension status as a marker of progressive end-organ damage.
13.1.6 Study limitations
There were a number of limitations noted in the study. First, not all hypertension patients in Soweto are managed by the Cardiology Unit at the Chris Hani Baragwanath Hospital, as patients of African ancestry rarely use private health care facilities, and it is possible that many patients were missed. Finally, clinical data were not captured for all patients in this study and therefore relied on clinical diagnosis.
13.1.7 Study conclusions
Previous findings from urban-dwelling areas in sub-Saharan Africa have demonstrated an increase in the prevalence of hypertension due to epidemiologic transition [80,85]. Overall, this study revealed that progressive forms of heart disease were a factor of undetected and untreated hypertension, most notably hypertensive HF. This observation was strengthened in later analyses of de novo presentations captured by the Heart of Soweto Study over a more prolonged period [86]. As an initial warning, these data reinforced the need to develop and implement cost-effective prevention, screening and management programs in African communities to decrease the risk of developing hypertension in the first instance and to reduce the incidence of more advanced forms of heart disease (most notably hypertensive HF) in those already affected.
13.2 A predominance of hypertensive HF in the Abuja Heart Society cohort of urban Nigerians: A prospective clinical registry of 1,515 de novo cases
Ojji D, Stewart S, Ajayi S, Manmak M, Silwa K. A predominance of hypertensive heart failure in the Abuja Heart Society cohort of urban Nigerians: a prospective clinical registry of 1515 de novo cases. European Journal of Heart Failure 2013; 15(8):835–42. [87]
13.2.1 Study background
There have been substantive changes in global disease patterns, with non-communicable diseases emerging as a major cause of morbidity and mortality, due to the shift in epidemiological and demographical health determinants in LMIC [88,89]. Significantly, CVD is now more likely to occur in adults in sub-Saharan Africa than in residents of high-income countries [90]. Unfortunately, data on patterns of heart disease in sub-Saharan Africa remain limited, due to the continued underestimation of the future threat posed by the emergence of CVD and the concurrent emphasis on communicable diseases such as malaria and HIV/AIDS [90]. To our knowledge, the last available research on forms of heart disease in Nigeria was published in the 1970s.
13.2.2 Study aims
The aim of this study was to examine the pattern of heart disease in Abuja, Nigeria, one of the fastest growing and populous cities in Nigeria, as well as to compare the results with similar data obtained from the Heart of Soweto Study in South Africa.
13.2.3 Study methods
13.2.3.1 Patient enrollment
During the period April 2006 to April 2010, every consecutive patient referred for the first time to the Cardiology Unit of the University of Abuja Teaching Hospital was examined. Overall, 1,586 patients were enrolled; of these, 71 patients were excluded from the study as they did not present any signs or symptoms of CVD, leaving a total of 1,515 study patients. All patients provided informed consent before enrollment in the study.
13.2.4 Study findings
As shown in Table 13.1, women patients were more likely than men to present as obese (OR 1.78, 95% CI 1.20–2.34), with hypertension (OR 1.96, 95% CI 1.26–2.65), and with palpitations (OR 1.68, 95% CI 1.41–2.42). Alternatively, men were older (2 years); were more likely to present with diabetes (OR 1.77, CI 1.25–2.37), HF (OR 1.61, 95% CI 1.19–2.32), or stroke (OR 1.62, 95% CI 1.18–2.20); and were more likely to report cigarette smoking (OR 1.95, 95% CI 1.83–2.65).
Table 13.1 Patients’ demographic and clinical characteristics.
| Women (n = 768) | Men (n = 747) | Total (n = 1,515) | |
| Demographic characteristic | |||
| Age (years) | 48.1 ± 14.2 | 49.9 ± 13.0 | 49.0 ± 13.7 |
| Family history of CVD | 33 (4.3%) | 43 (5.8%) | 76 (5.0%) |
| History of cigarette smoking | 96 (1.1%) | 106 (14.2%) | 115 (7.6%) |
| Clinical characteristic | |||
| Hypertension | 586 (76.3%) | 397 (53.1%) | 983 (64.9%) |
| Dyslipidemia | 108/445 (24.3%) | 96/476 (20.2%) | 205/913 (22.5%) |
| BMI > 30 (kg/m2) | 263 (34.2%) | 136 (18.2%) | 409 (27.0%) |
| Fasting blood sugar | 5.5 ± 2.6 | 5.7 ± 2.7 | 5.6 ± 2.6 |
| Multiple risk factors | 72 (9.4%) | 110 (14.7%) | 182 (12.0%) |
| Heart rate (beats/min) | 85.5 ± 18.3 | 80.2 ± 17.2 | 82.9 ± 18.3 |
| Systolic BP (mm Hg) | 136.1 ± 27.2 | 138.1 ± 28.5 | 137.1 ± 27.9 |
| Diastolic BP (mm Hg) | 86.5 ± 16.3 | 89.3 ± 17.6 | 87.9 ± 17.0 |
| Structural valvular disease | 22 (2.9%) | 33 (4.4%) | 55 (3.6%) |
| HF | 261 (34.0%) | 214 (28.6%) | 475 (31.4%) |
| CAD | 0 (0%) | 3 (0.4%) | 3 (0.2%) |
| Type 2 diabetes | 40 (5.2%) | 73 (9.8%) | 113 (7.5%) |
| Stroke | 22 (2.9%) | 50 (6.7%) | 72 (4.8%) |
| HIV infection | 7 (0.91%) | 10 (1.3%) | 17 (1.1%) |
| Anemia | 51 (6.6%) | 30 (4.0%) | 81 (5.3%) |
| Renal disease | 329 (42.8%) | 328 (43.9%) | 657 (43.4%) |
| eGFR (mL/min/1.73 m2) | 86.9 ± 53.8 | 84.9 ± 46.3 | 85.5 ± 50.1 |
| Chest pain/angina | 153 (19.9%) | 147 (19.7%) | 300 (19.8%) |
| NHYA Class II/III-IV | 30/92 | 27/76 | 57/168 |
| Edema | 389 (50.7%) | 377 (50.5%) | 766 (50.6%) |
| Palpitations | 314 (40.9%) | 219 (29.3%) | 533 (35.2%) |
As also shown in Figure 13.2, HF was found in 475 (31.1%) patients, with the most common cause of HF being hypertension (60.6%), followed by idiopathic dilated CMO (12%), rheumatic valvular disease (8.6%), and PPCMO (5.3%). Overall, there were no sex differences with regard to ECG presentation; however, echocardiographic findings showed that men were more likely than women to have larger ventricles and a lower mean LVEF.
Figure 13.2 Pattern of HF in study patients.
13.2.4.1 Comparisons to the Heart of Soweto Study
When comparing results from the Heart of Soweto Study to the findings of this study (Table 13.2), it was found that Soweto patients mainly comprised women (62%), were 2 to 3 years older, and reported a greater number of multiple risk factors (58.6% versus 12%) than the Abuja patients. They also displayed higher rates of cigarette smoking (41.5% versus 7.6%), HFpEF (23.4% versus 5.7%), LV systolic dysfunction (26.1% versus 17.6%), angina/chest pain (28.3% versus 19.8%), anemia (9.8% versus 5.3%), renal dysfunction (7.2% versus 5.9%), bundle branch block on 12-lead ECG (7.9% versus 5.1%), HIV infection (4.7% versus 1.1%), AF (6.4% versus 3.9%), and type 2 diabetes (10.4% versus 7.5%) when compared with the Abuja patients. However, the Abuja patients exhibited higher levels of hypercholesterolemia (22.5% versus 10%) and edema (50.6% versus 31%) relative to the Soweto patients.
Table 13.2 Patients’ demographic and clinical characteristics according to the Abuja cohort and the Soweto cohort.
| Abuja Cohort (n = 1,515) | Soweto Cohort (n = 1,593) | |
| Demographic characteristic | ||
| Age (years) | 49.0 ± 13.7 | 52.8 ± 17.1 |
| Clinical characteristics | ||
| History of CVD | 76 (5.0%) | 405 (25.4%) |
| Cigarette smoking | 115 (7.6%) | 661 (41.5%) |
| Hypercholesterolemia | 205 (22.5%) | 159 (10.0%) |
| Multiple risk factors | 182 (12.0%) | 933 (58.6%) |
| Type 2 diabetes | 113 (7.5%) | 165 (10.4%) |
| Bundle branch block on ECG | 68 (5.1%) | 124 (7.9%) |
| Heart rate (beats/min) | 82.9 ± 18.3 | 86.0 ± 21.8 |
| Systolic BP (mm Hg) | 137.1 ± 27.9 | 130.0 ± 27.1 |
| Diastolic BP (mm Hg) | 87.9 ± 17.0 | 73.0 ± 16.6 |
| HFpEF | 87 (5.7%) | 373 (23.4%) |
| LVEF | 64.8 ± 20.6 | 53.0 ± 17.4 |
| LV systolic dysfunction | 266 (17.6%) | 415 (26.1%) |
| AF | 52 (3.9%) | 102 (6.4%) |
| Anemia | 81 (5.3%) | 156 (9.8%) |
| Renal dysfunction | 90 (5.9%) | 115 (7.2%) |
| HIV infection | 17 (1.1%) | 74 (4.7%) |
| Angina/chest pain | 300 (19.8%) | 451 (28.3%) |
| NYHA Class III or IV | 168 (11.1%) | 486 (30.5%) |
| Edema | 766 (50.6%) | 494 (31.0%) |
13.2.5 Study interpretation
Overall, this Nigerian study revealed hypertension as the primary diagnosis in more than half of the study patients (more women than men) presenting at the Cardiology Unit of the University of Abuja Teaching Hospital. This finding was consistent with the results of the Heart of Soweto Study, where 64% of women and 36% of men presented newly diagnosed forms of CVD. As hypothesized, hypertension and hypertensive HF (with associated LVH) were the most common primary diagnoses, confirming previous observations that hypertension and its clinical consequences are common among those of African ancestry relative to other races. Abuja women were more likely than men to present with a primary diagnosis of hypertension, hypertensive LVH, obesity, palpitations, and anemia. However, men were more likely to report cigarette smoking and to present with type 2 diabetes, HF, and history of stroke. Consistent with these observations, men had larger LV parameters and worse LV systolic function. The study sites selected in the Abuja study as well as the Heart of Soweto Study offer true representations of the community’s spectrum of heart disease and provide indicators of more progressive heart disease cases. Higher levels of edema (indicative of congestion) and systolic and diastolic BP levels were found in Abuja; this can be explained by the sample’s comprising only patients of African ancestry, while the Soweto cohort included different racial groups. Previous studies have reported a higher rate of fluid retention in cardiovascular patients of African ancestry compared to Asians and Caucasians, due to differences in salt-sensitive activation of the renin-angiotensin system [91]. Soweto patients displayed a higher prevalence of CAD when compared with the Abuja patients, attributable to a higher rate of risk factors such as cigarette smoking (41% versus 7.5%), type 2 diabetes (10.0% versus 7.5%), and perhaps HIV infection (5.0% versus 1.1%)—see Chapter 10. Hypertensive HF, RHF, and HF due to idiopathic dilated CMO were the three most common forms of HF in this study cohort. These results resembled those of the Heart of Soweto Study, with the exception of the finding of right-sided HF secondary to cor pulmonale as the third most common form of HF. In the Abuja study, right-sided HF occurred in 2.5% of the patients, contrasting with 27% in the Heart of Soweto patients. The higher prevalence of cor pulmonale and RHF in Soweto patients can likely be explained by a higher rate of smoking (41% versus 7.5%), more exposure to industrial pollutants, and a higher altitude of residence (see Chapter 15). The hypertension prevalence among the Abuja patients was 61%, consistent with previous reports [33,91], although slightly higher than the 53% prevalence reported in the Heart of Soweto Study (see Chapter 6). The prevalence of cigarette smoking (7.6%), hypercholesterolemia (22.5%), and type 2 diabetes (7.5%) in the Abuja study were lower than in Western communities, indicating a disease pattern in true transition. Overall, a significant proportion of Abuja patients were symptomatic on presentation, and the late presentation of HF patients explains the increasing rates of morbidity and mortality observed in this population.
13.2.6 Study limitations
As this study was conducted in a tertiary care facility, patients with milder forms of CVD may have been missed; therefore, the study data may underrepresent the Abuja population. In addition, Abuja patients may have approached other tertiary care facilities and have therefore not been captured.
13.2.7 Study conclusions
In conclusion, the most common cause of de novo HF presentations in Abuja, Nigeria, was hypertension, a finding that supports those of the earlier Heart of Soweto Study. These findings indicate the need for wider-ranging strategies to prevent, treat, and control the number of adults affected by hypertension and its clinical consequences, most notably hypertensive HF.
13.3 Hypertensive HF in Nigerian Africans
Ogah O, Sliwa K, Akinyemi J, Falase A, Stewart S. Hypertensive heart failure in Nigerian Africans: insights from the Abeokuta Heart Failure Registry. Journal of Clinical Hypertension 2015; 17(4):263–72. [92]
13.3.1 Study background
Hypertension is strongly associated with cardiovascular-related morbidity and mortality and is accountable for 7.5 million deaths worldwide [78,93,94]. Previous studies have demonstrated that the majority of these deaths occur in young to middle-aged individuals in developing countries and that hypertension is expected to rise by 89% in sub-Saharan Africa, compared to 24% in other countries [78,95]. Despite decreasing in many developed countries, mean systolic BP levels are on the rise in developing countries [93]. Given these findings and hypertension’s status as the most common risk factor for heart disease in Nigeria, the scarcity of education, treatment, and management for hypertension and the associated increasing burden of hypertension-related complications are a serious concern [16,29,74,87,96,97].
13.3.2 Study aims
The aim of the study was to investigate the demographic and clinical characteristics and clinical outcomes among patients with hypertensive HF in Abeokuta, Nigeria.
13.3.3 Study methods
As described in greater detail in Chapter 12, as part of the Abeokuta HF Registry, a total of 452 HF patients were admitted to the Federal Medical Centre Abeokuta. Of these, 355 (78.5%) were known hypertensive heart disease cases (35 patients being excluded due to insufficient BP data). Patients were followed up at 1, 3, and 6 months to determine their well-being, medication prescription, rehospitalization history, and/or survival status.
13.3.4 Study findings
As shown in Table 13.3, women were more likely to be older, uneducated, and unemployed, while men were more likely to reside in a rural area. The majority of the cardiovascular risk factors and comorbidities were more prevalent in men, with the exception of asthma and arthritis, which were more frequent in women. Women were more likely to be overweight and obese, with a slightly longer length of admission and a higher pulse rate.
Table 13.3 Patients’ demographic and clinical characteristics.
| Women (n = 136) | Men (n = 184) | All (n = 320) | |
| Demographic characteristics | |||
| Age (years) | 60.6 ± 14.5 | 58.4 ± 12.4 | 59.3 ± 13.4 |
| Rural resident | 37 (27.2%) | 48 (26.1%) | 85 (26.6%) |
| Uneducated | 49 (51.6%) | 36 (27.1%) | 85 (37.3%) |
| Cardiovascular risk factors and comorbidities | |||
| Family history of CVD | 7 (5.1%) | 13 (7.1%) | 20 (6.3%) |
| Cigarette smoker | 7 (5.1%) | 53 (28.8%) | 60 (18.7%) |
| Type 2 diabetes | 17 (12.5%) | 22 (12.0%) | 39 (12.2%) |
| BMI (kg/m2) | 24.5 ± 5.7 | 24.0 ± 5.0 | 24.2 ± 5.3 |
| Asthma | 4 (2.9%) | 3 (1.6%) | 7 (2.2%) |
| COPD | 2 (1.5%) | 6 (3.3%) | 8 (2.5%) |
| HIV infection | 1 (1.5%) | 3 (3.4%) | 4 (2.7%) |
| Clinical and laboratory characteristics | |||
| NYHA class | |||
| II | 21 (15.4%) | 36 (19.6%) | 57 (17.8%) |
| III | 92 (67.6%) | 109 (59.2%) | 201 (62.8%) |
| IV | 23 (16.95) | 39 (21.2%) | 62 (19.4%) |
| Signs and symptoms | |||
| Heart rate (beats/min) | 94.7 ± 18.7 | 97.4 ± 19.1 | 96.2 ± 18.9 |
| Systolic BP (mm Hg) | 143.0 ± 19.4 | 143.8 ± 32.9 | 143.5 ± 32.1 |
| Diastolic BP (mm Hg) | 89.6 ± 19.4 | 91.1 ± 21.5 | 90.5 ± 20.6 |
| Basal crepitation | 110 (80.9%) | 160 (87.0%) | 270 (84.4%) |
| Hepatomegaly | 85 (62.5%) | 116 (63.0%) | 210 (62.8%) |
| Leg edema | 102 (75.0%) | 140 (76.1%) | 242 (75.6%) |
| Nocturnal cough | 126 (92.6%) | 166 (90.2%) | 292 (91.3%) |
| Paroxysmal nocturnal dyspnea | 111 (81.6%) | 157 (82.1%) | 262 (81.9%) |
| Raised Jugular Venous Pressure | 82 (60.3%) | 128 (69.6%) | 210 (65.6%) |
| Third heart sound | 92 (67.6%) | 115 (62.5%) | 207 (64.7%) |
| Laboratory findings | |||
| Fasting glucose (mg/dL) | 113.3 ± 56.2 | 113.4 ± 47.6 | 113.3 ± 51.2 |
| Total cholesterol (mg/dL) | 174.7 ± 68.6 | 162.9 ± 76.7 | 166.2 ± 74.1 |
| eGFR | 93.8 ± 50.7 | 95.2 ± 52.6 | 94.6 ± 51.7 |
As shown in Table 13.4, women were more likely to present with impaired systolic function and evidence of LV dysfunction (including fractional shortening and abnormal LV filling patterns/geometry). In contrast, men were more likely to present with abnormalities in aortic root diameter, AF, longer QTc, LVH on 12-lead ECG (with strain patterns), and evidence of LV remodeling, including greater LV mass, interventricular septal wall thickness in diastole, and interventricular septal wall thickness in systole.
Table 13.4 Patients’ 12-lead ECG and echocardiography findings.
| Women (n = 136) | Men (n = 184) | All (n = 320) | |
| Aortic root diameter (cm) | 2.90 ± 0.39 | 3.24 ± 0.50 | 3.10 ± 0.50 |
| AF | 18 (13.2%) | 23 (12.5%) | 41 (12.8%) |
| Corrected QT (ms) | 450.3 ± 35.5 | 457.5 ± 35.5 | 454.8 ± 35.4 |
| LVH on 12-lead ECG | 136 (100%) | 173 (94.3%) | 309 (96.5%) |
| ECG LVH with strain pattern | 49 (36.4%) | 87 (47.2%) | 138 (43.0%) |
| LVEF (%) | 44.5 ± 16.3 | 41.8 ± 16.6 | 42.9 ± 16.5 |
| Fractional shortening (%) | 18.7 ± 8.6 | 17.4 ± 8.7 | 17.9 ± 8.7 |
| LV mass index (g/ht) | 81.1 ± 28.0 | 96.7 ± 41.8 | 90.4 ± 37.7 |
| Interventricular septal wall thickness in diastole (cm) | 1.28 ± 0.29 | 1.40 ± 0.41 | 1.35 ± 0.37 |
| Interventricular septal wall thickness in systole (cm) | 1.48 ± 034 | 1.67 ± 0.55 | 1.60 ± 0.85 |
| LV internal diameter in diastole (cm) | 5.08 ± 1.40 | 5.84 ± 1.47 | 5.52 ± 1.49 |
| Left atrial area | 24.8 ± 7.36 | 27.7 ± 8.3 | 26.6 ± 8.1 |
| LV filling pattern (n = 262) | |||
| Systolic HF | 59.1% | 69.9% | 182 (69.5%) |
| Diastolic HF | 40.9% | 30.1% | 96 (36.6%) |
| Impaired relaxation | 27.2% | 26.4% | 70 (26.7%) |
| Moderate-to-severe aortic regurgitation | 46.7% | 43% | 125 (47.7%) |
| Moderate-to-severe MR | 80.3% | 78% | 207 (79.0%) |
| Moderate-to-severe tricuspid regurgitation | 63.9% | 58.2% | 159 (60.7%) |
| Pseudo-normalized filling | 45.6% | 45.3% | 119 (45.4%) |
| Restrictive filling | 27.2% | 28.3% | 73 (27.9%) |
| LV geometry (n = 263) | |||
| Concentric hypertrophy | 41.7% | 43.2% | 42.6 |
| Concentric remodelling | 12.0% | 3.9% | 19 (7.2%) |
| E/A ratio | 1.95 ± 1.35 | 2.11 ± 1.52 | 2.05 ± 1.45 |
| Eccentric hypertrophy | 42.6% | 48.4% | 121 (46.0%) |
| Mitral A-wave | 0.57 ± 0.28 | 0.50 ± 0.23 | 0.53 ± 0.25 |
| Mitral E-wave | 0.85 ± 0.32 | 0.80 ± 0.28 | 0.82 ± 0.29 |
| Normal geometry | 3.7% | 4.5% | 11 (4.2%) |
| LV internal diameter systole (cm) | 4.15 ± 1.31 | 4.86 ± 1.43 | 4.57 ± 1.49 |
| LV mass (g) | 283.9 ± 100.4 | 376.4 ± 140.8 | 338.4 ± 133.6 |
| LV posterior wall thickness diastole (cm) | 1.15 ± 0.35 | 1.22 ± 0.30 | 1.19 ± 0.36 |
| LV posterior wall thickness systole (cm) | 1.65 ± 0.37 | 1.66 ± 0.38 | 1.65 ± 0.37 |
| QRS duration (ms) | 104.4 ± 25.5 | 113.1 ± 23.9 | 109.8 ± 24.7 |
| QT interval (ms) | 358.8 ± 54.6 | 368.5 ± 36.6 | 364.8 ± 44.3 |
| Relative wall thickness | 0.47 ± 0.15 | 0.44 ± 0.15 | 0.45 ± 0.15 |
13.3.4.1 Treatment patterns
Overall, 319 (99.1%) patients were prescribed an ACE inhibitor/angiotensin II receptor blockers, 278 (86.9%) a loop diuretic, 260 (81.3%) spironolactone, 234 (73.1%) digoxin, 98 (30.6%) a calcium channel blocker, 49 (15.3%) hydralazine/isosorbide, 25 (7.8%) a thiazide diuretic, and only 9 (2.7%) a beta blocker.
13.3.4.2 Health outcomes
Median length of stay was 9 days and was similar for men and women. In-hospital case-fatality was 3.4% and 3.8% for men and women, respectively. Thereafter, 30-, 90-, and 180-day case-fatality was 0.9% (95% CI 0.2–3.5), 3.5% (95% CI 1.7–7.3), and 11.7% (95% CI 7.8–17.5), respectively. Rehospitalization rates at 30 days, 90 days, and 180 days were 4.2% (95% CI 2.3–7.6), 5.6% (95% CI, 3.3–9.5), and 7.3% (95% CI 4.5–11.7), respectively. Compared with patients who survived at 180 days, those who died were more likely to be NYHA Class III or IV (86.7% versus 38.7%, p < .001), to have lower systolic BP (130.7 ± 20.9 mmHg versus 144.1 ± 32.4 mm Hg, p = .030), lower diastolic BP (80.0 ± 13.7 versus 89.3 ± 18.9, p = .044), lower pulse pressure (42.7 ± 13.3 mm Hg versus 53.5 ± 12.1 mm Hg, p = .009), and a higher serum creatinine (2.2 ± 2.6 versus 1.2 ± 1.0, p = .005). After multiple logistic regression analysis, only serum creatinine was an independent predictor of mortality at 180 days (adjusted OR, 1.76; 95% CI 1.17–2.64). The only significant difference in rehospitalization status was serum potassium level (higher in those readmitted to hospital).
13.3.5 Study interpretation
This study was the first study on hypertensive HF in Nigeria. The condition was found to be particularly prevalent in middle-aged individuals, with only 46% of the study patients being aged >60 years. Patterns of severe LV remodeling, comorbid conditions, and frequent functional valvular dysfunction were particularly frequent in de novo HF patients. As observed earlier in this chapter, late presentation to tertiary care could explain the alarmingly high prevalence of hypertensive HF, as individuals with elevated BP levels are frequently unaware of their condition and can sustain organ damage without preventive treatment. A high proportion of patients were prescribed spironolactone, or ACE inhibitor/angiotensin II receptor blockers therapy, but use of hydralazine/isosorbide and beta blockers was low, perhaps due to disease severity, edema, or low BP levels at presentation, or poverty (as patients pay out of pocket). The low rates of stroke in Nigeria relative to those observed in developed countries may be partially due to the fact that most individuals at risk of stroke secondary to untreated hypertension develop hypertensive HF first and die before they experience a stroke. Such competing risks are complex and require further investigation. In comparison with European and North American cohorts with HF, the overall demographic and clinical profile (in addition to associated mortality and morbidity rates) of the current cohort highlights some similarities but many profound differences. The predominance of hypertensive HF, late presentations, and the age of those affected are crucial factors in considering what evidence should be applied to improve health outcomes in this context. Overall, these findings highlight a gap in our knowledge of the burden of HF. They provide an opportunity for future interventions to focus on educating the Nigerian population as well as training the physicians in local medical clinics to combat hypertension and hypertensive heart disease, a similar opportunity being evident throughout the African continent.
13.3.6 Study limitations
As this study was conducted in a tertiary care facility, it may not have captured all HF cases in the population. Biomarkers in this study were not assessed due to cost constraints. Finally, some of the newer parameters for assessing diastolic function were not used in this study.
13.3.7 Study conclusions
In conclusion, Nigerians who develop hypertensive HF experience high economic loss and disability-adjusted life-years, as they are commonly in their most productive years from a social and economic perspective. Late presentations are common among individuals with elevated BP levels due to lack of awareness and/or education. Nigerian communities should be educated in hypertensive HF prevention, early detection, treatment, and management.