|Year : 2017 | Volume
| Issue : 1 | Page : 9-14
Heart failure: Definition, classification, and pathophysiology – A mini-review
Saheed O Adebayo1, Taiwo O Olunuga1, Amina Durodola1, Okechukwu S Ogah2
1 Department of Internal Medicine, Cardiology Unit, Federal Medical Centre, Abeokuta, Nigeria
2 Department of Medicine, Division of Cardiology, University College Hospital, Ibadan, Nigeria
|Date of Web Publication||10-Mar-2017|
Okechukwu S Ogah
Department of Medicine, Division of Cardiology, University College Hospital, PMB 5116, Ibadan
Source of Support: None, Conflict of Interest: None
Heart failure is a clinical syndrome characterized by dyspnea, fatigue, and clinical signs of congestion leading to frequent hospitalizations, poor quality of life, and shortened life expectancy. It is a final common pathway to various cardiac conditions. It is a growing problem worldwide with serious consequences in Sub-Saharan Africa where it occurs at a younger age with limited resources to manage the condition. The incidence and prevalence vary worldwide. In this mini-review, we looked at the definition, classification, and pathophysiology of the condition.
Keywords: Cardiac failure, classification, definition, heart failure, pathophysiology
|How to cite this article:|
Adebayo SO, Olunuga TO, Durodola A, Ogah OS. Heart failure: Definition, classification, and pathophysiology – A mini-review. Nig J Cardiol 2017;14:9-14
|How to cite this URL:|
Adebayo SO, Olunuga TO, Durodola A, Ogah OS. Heart failure: Definition, classification, and pathophysiology – A mini-review. Nig J Cardiol [serial online] 2017 [cited 2018 Jan 17];14:9-14. Available from: http://www.nigjcardiol.org/text.asp?2017/14/1/9/201913
| Introduction|| |
Heart failure (HF) is a clinical syndrome characterized by dyspnea, fatigue, and clinical signs of congestion leading to frequent hospitalizations, poor quality of life, and shortened life expectancy. It is a final common pathway to various heart diseases. HF is a growing problem worldwide with serious consequences in Sub-Saharan Africa (SSA) where there is limited resources.,,
The incidence and prevalence of congestive HF vary worldwide. In the United States of America, the incidence is estimated as 500,000 new cases annually and prevalence of 5.1 million people., There is paucity of population-based data from developing countries including Nigeria.
Various studies from different regions of the country have documented etiology of HF with hypertension, cardiomyopathy, and rheumatic heart diseases (RHDs) as the leading causes.,,,,,,,,,,,
A recent report from the SSA Survey of HF revealed that acute HF in SSA appears to affect younger patients in the prime of their lives and is mainly caused by preventable and treatable causes such as hypertension (43.9%), dilated cardiomyopathy (DCM) (19.5%), and RHD (15%) among other causes.,
Despite advancements in medical, device-based, and surgical management of HF, outcome is still not encouraging even in Western countries. These could be attributed to aging population, delay in instituting evidence-based therapy as a result of misdiagnosis, poor application of therapy, nonavailability of therapy, comorbidities, complications, noncompliance with medications, lack of funds, and negative sociocultural beliefs of patients, especially in the developing world.
The clinical manifestation of HF significantly impairs the functional capability of the patients to varying degrees. This is usually assessed with symptoms and noninvasively with echocardiography. One of the widely employed methods is New York Heart Association (NYHA) classification which assesses the functional impairment and disease severity. It is a simple, quick, and easily administered but subjective assessment which has been widely used in routine clinical and research activities. It has good correlation with prognostic indices. Likewise, distance covered during 6 min walk test has also been employed to assess functional status. It is an objective measure of submaximal exercise capacity with good prognostic implications.,,,, In addition, left ventricular (LV) systolic function routinely determined with LV ejection fraction (EF), though correlates poorly with symptoms, has good prognostic and therapeutic significance.
In this minireview, we explore the definition, classification, and pathophysiology of HF.
Definitions of heart failure
HF is a complex clinical syndrome and as such many authors have put forward different definitions in the past [Table 1].
European Society of Cardiology in 2008 defined HF as “an abnormality of cardiac structure or function leading to failure of the heart to deliver oxygen at a rate commensurate with the requirements of the metabolizing tissues despite normal filling pressures (or only at the expense of increased filling pressures).” [Table 2] shows the major and minor criteria for the diagnosis of HF.
| Epidemiology and Classification|| |
HF is a burgeoning problem worldwide with more than 26 million people affected. The overall prevalence of HF in the adult population in developed countries is 1%–3% with exponential rise with age. It affects 6%–10% of people over the age of 65 years.
Although the relative incidence of HF is lower in women than men, women constitute at least half of the cases because of their longer life expectancy.
Population-based studies on the incidence and prevalence of HF in developing countries are evolving. It was estimated that cardiovascular (CV) diseases accounted for 7%–10% of all medical admissions to African hospitals and HF constitutes 3%–7% of these admissions.
Several studies have demonstrated that hypertension
/hypertensive heart disease, DCM, chronic RHDs, corpulmonale, and pericardial diseases constitute the major etiological factors of HF in Nigeria. [3,14-17,30-32]
In the Abeokuta HF registry, (a local registry of HF patients seen at Federal Medical Centre and Sacred Heart Hospital, both in Abeokuta) the mean age of 56 ± 15 years was reported, with women being older than men and an overall prevalence of 9% among all medical admissions.,,,
The most common etiology is hypertensive HF (66%), followed by DCM (12%), corpulmonale (8%), RHDs (3%), and pericardial diseases. Hypertension and cardiomyopathy are also the leading causes in Sagamu, Kano, and other parts of the country. [3, 16, 17, 30, 31]
With widespread availability of the echocardiography, HF is now routinely classified based on EF as HF with preserved EF (HFpEF: EF ≥50%), HF with reduced EF (HFrEF: EF ≤40%), and HF with mid-range EF (EF = 41%–49%).
There are no symptoms or signs that specifically distinguish between the three categories. However, the classification has good therapeutic importance as HFrEF has clear line of management with evidence-based disease modifying agents such as angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blockers (ARB), beta blockers (BBs), and aldosterone receptor blockers while the management of the HFpEF currently focuses on comorbidities, precipitants, and etiology as there is no treatment that convincingly improves the morbidity and mortality.,,
Patients with HFpEF are usually older, female, hypertensive with nondilated chambers while the counterpart with HFrEF is usually younger with progressive chamber dilatation and reduced stroke volume, majorly due to ischemic heart disease in Caucassians while hypertension accounts chiefly for the cases in Africans.,
Use of the disease modifying agents in our environment has been noted to be similar to what is obtainable in the Western world as depicted by various studies., However, digoxin use is significantly higher in our cohort. This may be attributed to its relative availability and affordability as compared to other inotropes and the prevalence of reduced systolic function.
The use of hydralazine/nitrates combination has also been documented to be low. This is largely due to lack of familiarity with the medications as well as lack of local studies to corroborate beneficial outcomes from the African-American HF study., The result of bitreatment with hydralazine/isosorbide dinitrate versus placebo on top of standard care in African patients admitted with acute HF (BAHEF trial) has just been released. The authors found that hydralazine/isosorbide combination showed nonstatistically significant benefit over placebo on secondary end points (change in dyspnea severity at day 7 or discharge, systolic blood pressure, weight, 6-min walk test distance at week 24, and echocardiographic cardiac size and function). There was no benefit on primary end point of death or readmission within 6 months.
As regards prognosis, Ogah et al. recently looked at the short-term outcomes after discharge in Abeokuta HF registry and found that the mortality was 4.2% at 30 days which increased to 7.5% at 6 months with patients with pericardial diseases having initial highest mortality. Factors associated with poor outcomes as noted by various authors in our environment include low EF, anemia, low blood pressure, low body mass index, impaired renal function, and rhythm disorders.,
Surprisingly, hyponatremia and hypokalemia were predictors of favorable outcomes from the report by Ogah et al. as opposed to what is known in Caucasians.,,,, This was attributed to better diuretic response in our cohort and possibly due to the fact that the pathophysiology of HF in blacks is less dependent on sodium. Likewise, obesity had been associated with favorable outcome in HF patients.,
On the other hand, higher rates of readmission within 6 months were noted in those with older age, lower body mass index, low literacy, presence of atrial fibrillation, renal dysfunction, and valvular dysfunction.
| Pathophysiology|| |
HF is a complex pathophysiologic condition in which complex compensatory mechanisms and adaptive changes come into play. No single model has been able to fully explain these pathophysiologic mechanisms. The clinical models described so far include cardiorenal, hemodynamic, and neurohumoral mechanisms. These mechanisms initially are able to restore CV function to a normal homeostatic range and the patient remains asymptomatic. However, the sustained activation of these systems can lead to end organ damage with worsening LV remodeling and subsequent cardiac decompensation.
These compensatory mechanisms include adrenergic nervous system activation, activation of renin-angiotensin-aldosterone system, cytokine system activation, increased myocardial contractility, and increased activation of vasodilatory molecules including atrial and brain natriuretic peptides, prostaglandins (PGE2 and PGI2), and nitric oxide that offsets the excessive peripheral vascular constriction.,
It is also established that genetic background, sex, age, and environment may influence these compensatory mechanisms. The resultant adaptive changes within the myocardium are collectively referred to as LV remodeling. The LV remodeling stems from alteration in myocyte biology, myocardial changes (myocardial loss, necrosis, apoptosis, and autophagy), alteration in extracellular matrix (matrix degradation and myocardial fibrosis), and alteration in LV chamber geometry (LV dilation, increase in LV sphericity, LV wall thinning and mitral valve incompetence).,
| Clinical Presentation|| |
The clinical features of HF have been classified into major and minor criteria according to the Framingham study [Table 3].
|Table 3: New York Heart Association functional classification of heart failure|
Click here to view
| Staging of Heart Failure|| |
There are different ways of staging severity of HF based on symptoms, functional capacity, and degree of structural cardiac damage.
NYHA is a widely used classification. It emphasizes the functional capacity of the patients. It is classified based on severity of symptoms and limitation of activities [Table 4].
|Table 4: Comparison of American College of Cardiology/American Heart Association and New York Heart Association classification of heart failure|
Click here to view
In the Abeokuta HF registry, majority of patients were in NYHA Class III (65.3%) followed by 20% of patients in Class IV and 14.7% in Class II. Karaye and Sani reported that 22.8% of their HF patients were in NYHA III and 77.2% were in NYHA IV.
The American College of Cardiology/American Heart Association has staged HF based on the presence of risk factors, degree of structural damage, and severity of symptoms into Stages A to D with specific interventions at each stage.,
- Stage A: At high risk for HF but without structural heart disease or symptoms of HF. For example, hypertensive patient without symptoms and cardiac structural damage. Therefore, intervention at this stage focuses on life style, health education, and optimal control of blood pressure and other comorbidities
- Stage B: Presence of structural heart disease but without symptoms or signs of HF, for example, asymptomatic hypertensive patient with LV hypertrophy or asymptomatic mitral valve prolapse. Therefore, intervention would be to reverse the damage, retard the progression, and prevent the development of HF in addition to the interventions for Stage A
- Stage C: Presence of structural heart disease with previous or current symptoms of HF, for example, hypertensive HF patient or symptomatic mitral valve prolapse. Interventions at this stage entail all measures under stage A and B, diuretics for fluid retention, use of ACEI or ARB, BB, aldosterone antagonist, digitalis, and in selected cases devices (biventricular pacing or implantable defibrillators)
- Stage D: Presence of refractory symptoms that require special interventions, for example, device-based treatment or cardiac transplantation.
| Conclusion|| |
HF is prevalent worldwide with variable etiology in the Western world compared to SSA. Use of the disease modifying agents in our environment has been noted to be similar to what is obtainable in the Western world but predictors of favorable outcomes were found not to be necessarily the same. There is therefore need for further studies on the similarities and differences in HF in different geographic locations including genomics.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Gary SF, Tang WH, Walsh RA. Pathophysiology of Heart Failure. In: Valentin Fuster RA, Harrington RA, editors. Hurst's The Heart. 13th
ed. 2011. p. 719-38.
Sliwa K, Mayosi BM. Recent advances in the epidemiology, pathogenesis and prognosis of acute heart failure and cardiomyopathy in Africa. Heart 2013;99:1317-22.
Ojji D, Stewart S, Ajayi S, Manmak M, Sliwa K. A predominance of hypertensive heart failure in the Abuja Heart Study cohort of urban Nigerians: A prospective clinical registry of 1515 de novo
cases. Eur J Heart Fail 2013;15:835-42.
Ntusi NB, Mayosi BM. Epidemiology of heart failure in Sub-Saharan Africa. Expert Rev Cardiovasc Ther 2009;7:169-80.
Hunt SA, Abraham WT, Chin MH, Feldman AM, Francis GS, Ganiats TG, et al.
ACC/AHA 2005 Guideline Update for the Diagnosis and Management of Chronic Heart Failure in the Adult: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Update the 2001 Guidelines for the Evaluation and Management of Heart Failure): Developed in collaboration with the American College of Chest Physicians and the International Society for Heart and Lung Transplantation: Endorsed by the Heart Rhythm Society. Circulation 2005;112:e154-235.
Hunt SA, Abraham WT, Chin MH, Feldman AM, Francis GS, Ganiats TG, et al
.2009 Focused update incorporated into the ACC/AHA 2005 Guidelines for the Diagnosis and Management of Heart Failure in Adults A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines Developed in Collaboration With the International Society for Heart and Lung Transplantation. J Am Coll Cardiol 2009;53:e1-90.
Amoah AG, Kallen C. Aetiology of heart failure as seen from a National Cardiac Referral Centre in Africa. Cardiology 2000;93:11-8.
Owusu I. Causes of heart failure as seen in Kumasi, Ghana. Internet J Third World Med 2007;5:1538-4646.
Ogah OS, Okpechi I, Chukwuonye II, Akinyemi JO, Onwubere BJ, Falase AO, et al.
Blood pressure, prevalence of hypertension and hypertension related complications in Nigerian Africans: A review. World J Cardiol 2012;4:327-40.
Damasceno A, Mayosi BM, Sani M, Ogah OS, Mondo C, Ojji D, et al.
The causes, treatment, and outcome of acute heart failure in 1006 Africans from 9 countries. Arch Intern Med 2012;172:1386-94.
Mayosi BM. Contemporary trends in the epidemiology and management of cardiomyopathy and pericarditis in Sub-Saharan Africa. Heart 2007;93:1176-83.
McMurray JJ, Stewart S. Epidemiology, aetiology, and prognosis of heart failure. Heart 2000;83:596-602.
Tantchou Tchoumi JC, Ambassa JC, Kingue S, Giamberti A, Cirri S, Frigiola A, et al.
Occurrence, aetiology and challenges in the management of congestive heart failure in Sub-Saharan Africa: Experience of the Cardiac Centre in Shisong, Cameroon. Pan Afr Med J 2011;8:11.
Antony KK. Pattern of cardiac failure in Northern Savanna Nigeria. Trop Geogr Med 1980;32:118-25.
Ladipo GO, Froude JR, Parry EH. Pattern of heart disease in adults of the Nigerian Savanna: A prospective clinical study. Afr J Med Med Sci 1977;6:185-92.
Onwuchekwa AC, Asekomeh GE. Pattern of heart failure in a Nigerian teaching hospital. Vasc Health Risk Manag 2009;5:745-50.
Ojji DB, Alfa J, Ajayi SO, Mamven MH, Falase AO. Pattern of heart failure in Abuja, Nigeria: An echocardiographic study. Cardiovasc J Afr 2009;20:349-52.
Holland R, Rechel B, Stepien K, Harvey I, Brooksby I. Patients' self-assessed functional status in heart failure by New York Heart Association class: A prognostic predictor of hospitalizations, quality of life and death. J Card Fail 2010;16:150-6.
Roul G, Germain P, Bareiss P. Does the 6-minute walk test predict the prognosis in patients with NYHA class II or III chronic heart failure? Am Heart J 1998;136:449-57.
Guimarães GV, Bellotti G, Bacal F, Mocelin A, Bocchi EA. Can the cardiopulmonary 6-minute walk test reproduce the usual activities of patients with heart failure? Arq Bras Cardiol 2002;78:553-60.
Adedoyin RA, Adeyanju SA, Balogun MO, Akintomide AO, Adebayo RA, Akinwusi PO, et al.
Assessment of exercise capacity in African patients with chronic heart failure using six minutes walk test. Int J Gen Med 2010;3:109-13.
Adedoyin RA, Adeyanju SA, Balogun MO, Adebayo RA, Akintomide AO, Akinwusi PO. Prediction of functional capacity during six-minute walk among patients with chronic heart failure. Niger J Clin Pract 2010;13:379-81.
] [Full text]
Cahalin LP, Mathier MA, Semigran MJ, Dec GW, DiSalvo TG. The six-minute walk test predicts peak oxygen uptake and survival in patients with advanced heart failure. Chest 1996;110:325-32.
Mann DL, Chakinala M. Heart failure and Cor pulmonale. In: Longo DL, Fauci AS, Kasper DL, et al.
, editors. Harrison's Principles of Internal Medicine. 18th
ed. 2012. p
Mann DL. Pathophysiology of Heart Failure. In: Bonow RO, Mann DL, Zipes DP, Libby P, editors. Brauward's Heart Disease: A Textbook Of Cardiovascular Medicine. 9th
ed. Philadelphia PA: 2012. p. 487-503.
McMurray JJ, Adamopoulos S, Anker SD, Auricchio A, Böhm M, Dickstein K, et al.
ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012 The Task Force for the Diagnosis and Treatment of Acute and Chronic Heart Failure 2012 of the European Society of Cardiology. Developed in Collaboration with the Heart Failure Association (HFA) of the ESC. Eur Heart J 2012;33:1787-847.
Yancy CW, Jessup M, Bozkurt B, Butler J, Casey DE, Drazner MH, et al
. 2013 ACCF/AHA guideline for the management of heart failure: A report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2013;62:e147-239.
Steinberg BA, Zhao X, Heidenreich PA, Peterson ED, Bhatt DL, Cannon CP, et al.
Trends in patients hospitalized with heart failure and preserved left ventricular ejection fraction: Prevalence, therapies, and outcomes. Circulation 2012;126:65-75.
Mosterd A, Hoes AW. Clinical epidemiology of heart failure. Heart 2007;93:1137-46.
Familoni O, Olunuga T, Olufemi B. A clinical study of pattern and factors affecting outcome in Nigerian patients with advanced heart failure. Cardiovasc J Afr 2007;18:308-11.
Karaye KM, Sani MU. Factors associated with poor prognosis among patients admitted with heart failure in a Nigerian tertiary medical centre: A cross-sectional study. BMC Cardiovasc Dis 2008;8:16-24.
Falase AO, Aje A, Ogah OS. Management of hypertension in Nigerians: Ad hoc or rational basis? Niger J Cardiol 2015;12:158.
Ogah O, Akinyemi R, Ogbodo E, Ogah F. Cardiac emergencies in a Nigerian hospital: Data from the Abeokuta heart disease registry. Niger J Cardiol 2013;10:14.
Ogah OS, Adegbite GD, Akinyemi RO, Adesina JO, Alabi AA, Udofia OI, et al.
Spectrum of heart diseases in a new cardiac service in Nigeria: An echocardiographic study of 1441 subjects in Abeokuta. BMC Res Notes 2008;1:98.
Ogah OS, Falase AO, Carrington M, Stewart S, Sliwa K, editors. Hypertensive heart failure in Nigerian Africans: Insights from the Abeokuta heart failure registry. J Clin Hypertens 2015;17:263-72.
Ogah OS, Stewart S, Falase AO, Akinyemi JO, Adegbite GD, Alabi AA, et al
. Contemporary profile of acute heart failure in Southern Nigeria: Data From the Abeokuta heart failure clinical registry. JACC Heart Fail 2014;2:250-9.
Ponikowski P, Voors AA, Anker SD, Bueno H, Cleland JG, Coats AJ, et al
. 2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure. Eur Heart J 2015. doi:10.1093/eurheartj/ehw128.
Oyati A, Danbauchi S. Diastolic Heart Failure: Are There Specific Bedside Clinical Markers for its Diagnosis? Ann of Afr Med 2006;4:96-8.
Shah SJ, Gheorghiade M. Heart failure with preserved ejection fraction: Treat now by treating comorbidities. JAMA 2008;300:431-3.
Bhuiyan T, Maurer MS. Heart failure with preserved ejection fraction: Persistent diagnosis, therapeutic enigma. Curr Cardiovasc Risk Rep 2011;5:440-9.
Adebayo AK, Adebiyi AA, Oladapo OO, Ogah OS, Aje A, Ojji DB, et al.
Characterisation of heart failure with normal ejection fraction in a tertiary hospital in Nigeria. BMC Cardiovasc Disord 2009;9:52.
Taylor AL, Ziesche S, Yancy C, Carson P, D'Agostino R Jr., Ferdinand K, et al.
Combination of isosorbide dinitrate and hydralazine in blacks with heart failure. N Engl J Med 2004;351:2049-57.
Taylor AL, Ziesche S, Yancy CW, Carson P, Ferdinand K, Taylor M, et al.
Early and sustained benefit on event-free survival and heart failure hospitalization from fixed-dose combination of isosorbide dinitrate/hydralazine: Consistency across subgroups in the African-American Heart Failure Trial. Circulation 2007;115:1747-53.
Sliwa K, Damasceno A, Davison BA, Mayosi BM, Sani MU, Ogah O, et al.
Bi treatment with hydralazine/nitrates vs. placebo in Africans admitted with acute HEart Failure (BA-HEF). Eur J Heart Fail 2016;18:1248-58.
Ogah OS, Stewart S, Falase AO, Akinyemi JO, Adegbite GD, Alabi AA, et al
. Short-term outcomes after hospital discharge in patients admitted with heart failure in Abeokuta, Nigeria: Data from the Abeokuta heart failure registry: Cardiovascular topic. Cardiovasc J Afr 2014;25:217-23.
Kearney MT, Fox KA, Lee AJ, Prescott RJ, Shah AM, Batin PD, et al.
Predicting death due to progressive heart failure in patients with mild-to-moderate chronic heart failure. J Am Coll Cardiol 2002;40:1801-8.
Kearney MT, Nolan J, Lee AJ, Brooksby PW, Prescott R, Shah AM, et al
. A prognostic index to predict long-term mortality in patients with mild to moderate chronic heart failure stabilised on angiotensin converting enzyme inhibitors. Eur J Heart Fail 2003;5:489-97.
Klein L, O'Connor CM, Leimberger JD, Gattis-Stough W, Piña IL, Felker GM, et al.
Lower serum sodium is associated with increased short-term mortality in hospitalized patients with worsening heart failure: Results from the Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations of Chronic Heart Failure (OPTIME-CHF) study. Circulation 2005;111:2454-60.
Lee WH, Packer M. Prognostic importance of serum sodium concentration and its modification by converting-enzyme inhibition in patients with severe chronic heart failure. Circulation 1986;73:257-67.
Oyedeji AT, Balogun MO, Akintomide AO, Sunmonu TA, Adebayo RA, Ajayi OE. The “obesity paradox” in Nigerians with heart failure. Ann Afr Med 2012;11:212-6.
] [Full text]
Chase PJ, Davis PG, Bensimhon DR. The obesity paradox in chronic heart failure: What does it mean? Curr Heart Fail Rep 2014;11:111-7.
Ogah OS, Stewart S, Falase AO, Akinyemi JO, Adegbite GD, Alabi AA, et al.
Predictors of rehospitalization in patients admitted with heart failure in Abeokuta, Nigeria: Data from the Abeokuta heart failure registry. J Card Fail 2014;20:833-40.
Mann DL. Mechanisms and models in heart failure: A combinatorial approach. Circulation 1999;100:999-1008.
Ho KK, Pinsky JL, Kannel WB, Levy D. The epidemiology of heart failure: The Framingham Study. J Am Coll Cardiol 1993;22 4 Suppl A: 6A-13A.
Karaye K, Sani M. Demographic and clinical characteristics of heart failure patients in a Nigerian Tertiary Health Centre. Nig J Basic Clin Sciences 2008;1:26-36.
[Table 1], [Table 2], [Table 3], [Table 4]