Cardiovascular diseases (CVD) are diseases of the heart and the blood vessels (Figure 2) 18. It is known that cardiovascular diseases are multifactorial 18. The risk factors are high blood pressure, smoking, high blood cholesterol level, diabetes, depression 19 and family history 18. High blood low-density lipoprotein cholesterol levels are strongly associated with the risk of coronary heart disease but weakly with the risk of stroke 18. The coronary heart and cerebrovascular diseases are the CVD that cause the most death in adults worldwide 18.
CVD prevention is of a huge importance and the management should be multidisciplinary 20. The most known and considered as the best medical therapy includes CVD risk factor management: using pharmacological (antihypertensive, lipid-lowering, antithrombotic drugs and glucose level control for diabetic persons) and non- pharmacological measures (such as smoking cessation, healthy diet, weight loss and regular physical exercise) 20.
1. Coronary Heart Disease 18
In the industrialized countries, the coronary heart disease (CHD) (or ischemic heart disease), is the number one cause of death. In CHD, blood flow is reduced in one or more branches of the coronary arteries. This is due to atherosclerotic plaques protruding from the inner surface of the arteries thereby narrowing the lumen. The reduction of blood flow may result in angina pectoris (chest pain). The blood flow can also be blocked completely by a blood clot (thrombus). In this case, the heart muscle tissue is no longer provided with oxygen and nutrients. This may result in necrosis of the affected tissues (infarction) or even death. The atherosclerotic process starts with the lipid deposition and oxidation in the subendothelium of the arteries.
2. Cerebrovascular Disease 18
Cerebrovascular disease consists of two main forms: ischemic and hemorrhagic stroke. Ischemic stroke is caused by blockage of an artery in the brain by mechanisms similar to those in CHD. This is one of the most common types of stroke in North America and most of Europe. Hemorrhagic stroke is the most common type of stroke in Japan and China and is caused by the rupture of a blood vessel.
3. Peripheral Arterial Diseases
Peripheral arterial diseases (PAD) include all arterial diseases except for coronary arteries and aorta 20. Indeed, peripheral localizations, including the carotid and vertebral, upper extremities, mesenteric and renal arteries, affected mainly by atherosclerosis, are part of PAD 20. PAD must be distinguished from peripheral artery disease, which is a synonym for lower extremity artery disease (LEAD) 20.
The risk of PAD increase drastically with age and exposure to major cardiovascular risk factors including smoking, hypertension, dyslipidemia and diabetes 20. The therapeutic approach to patients with PAD include the management of specific symptoms of any localization and the risk related to a specific lesion, as well as the management of the increased risk to any CV event in these patients 20.
4. Rheumatic and Congenital Heart Diseases
Studies confirmed that heart diseases in children, especially rheumatic heart diseases (RHD), and congenital heart disease (CHD) are major health problems, in particular among children and young populations in developing countries (especially African and Asian) 4 5 6.
Indeed, it was reported that RHD are the main cause of acquired heart disease among young people worldwide 5 6. An underestimation of 15 million people suffering from RHD worldwide was reported, with 1.5% of this estimation dying every year 5. RHD are mainly caused by repeated acute rheumatic fever attacks following an infection by Group A Streptococci 5. Some studies mentioned that the prevention of RHD consist of the improvement of socio-economic conditions, primary prevention through antibiotic treatment of Group A Streptococci pharyngitis and secondary prevention of acute rheumatic fever recurrence by penicillin prophylaxis 5.
CHD is referring to the abnormalities in the heart’s structure or function that occur before birth (during embryogenesis). The incidence of CHD is about 19 to 75 per 1,000 live births. The dysregulation of heart development is the root of the disease 7. CHD affect most parts of the heart and can be divided into five sub-groups 7:
• Cyanotic heart disease: infants having cyanotic heart disease appear blue as a result of the mixing of oxygenated and deoxygenated blood
• Left-sided obstructive lesions: include hypoplastic left heart syndrome, mitral stenosis, aortic stenosis, aortic coarctation and interrupted aortic arch
• Septation defects: it affects septation of the atria, septation of the ventricles or formation of structures in the central part of the heart
• Bicuspid aortic valve (BAV)
• Patent ductus arteriosus
The most common congenital heart disease is BAV followed by septation defects 7. The mortality and morbidity rates depend on the severity of the congenital heart disease 7.
The prevalence of CHD varies between regions and countries due to genetic, environmental and epigenetic differences 5. It was reported that in Cameroon, 13% of patients with suspected cardiac pathologies (from 2 to 41 years old) were diagnosed with CHD 5. In Africa, 35% of heart failure in children were reported to be due to CHD 5. Improvements in in utero diagnosis and surgical techniques have improved the prospects for infants born with congenital heart diseases 7. Identification of the causative genes in inherited forms provided considerable knowledge 7. However, many issues still need to be addressed from biological and genetic points of views 7.
5. Deep Vein Thrombosis and Pulmonary Embolism
Deep vein thrombosis (DVT) and pulmonary embolism (PE) are collectively referred to as venous thromboembolism 8. The chronic sequelae of venous thromboembolism include post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension 9. Risk factors for venous thromboembolism can be hereditary or acquired (e.g. antithrombin deficiency, protein C deficiency, protein S deficiency, factor V Leiden, cigarette smoking, hypertension, diabetes, and obesity) 8 9. Most patients with venous thromboembolism can be treated with anticoagulants 8. It was reported that individuals who have a first episode of DVT or PE will have a recurrent event 8. DVT and PE represent the spectrum of one disease: thrombi form in deep veins in the calf and then propagate into the proximal veins, including and above the popliteal veins, from which they are more likely to embolize 9.
DVT mostly occurs in the legs, but can form on the arms, in the mesenteric and cerebral veins. It is considered as a complication of several inherited and acquired disorders but may also occur spontaneously 10 . It is often associated with factor V Leiden or prothrombin gene mutation 8. The pathophysiology of DVT involves damage to the vessel wall, slowing down of the blood flow and the increase in blood coagulability 10. The risk factors associated with DVT are age, cancer, surgery, immobilization, fractures, puerperium, paralysis, use of oral contraceptives and the antiphospholipid syndrome 10.
Despite advances in prophylaxis, diagnostic modalities and therapeutic options, PE remains the third most common cause of death from cardiovascular diseases after heart attack and stroke 8 9. PE most commonly originates from DVT of the legs, ranging from asymptomatic, incidentally discovered emboli to massive embolism causing immediate death 9. Acute pulmonary embolism can occur rapidly and unpredictably and may be difficult to diagnose 9. It was reported that patients treated for acute pulmonary embolism appear to be almost four times as likely to die of recurrent thromboembolism in the next year vs. patients treated for deep venous thrombosis (rate of death, 1.5% vs. 0.4%) 9. Studies showed that about 79% of patients who had PE have evidence of DVT in their legs 9. On the other hand, PE occurs in up to 50% of patients with proximal DVT 9.
Pulmonary embolism can be:
• Idiopathic, primary, and unprovoked: prognostic associated factors are: age (>65 years), long air travel associated thrombophilia, obesity, cigarette smoking, hypertension, metabolic syndrome and air pollution 8
• Secondary and provoked: prognostic associated factors are: immobilization, postoperative, trauma, oral contraceptives, pregnancy, postmenopausal hormonal replacement, cancer and acute medical illness 8
REFERENCES
1. Tijburg, L. B. M. et al. Tea Flavonoids and Cardiovascular Diseases : A Review. Crit. Rev. Food Sci. Nutr. 37, 771–785 (2009).
2. Kooy, K. Van Der, Hout, H. Van, Marwijk, H., Marten, H. & Stehouwer, C. Depression and the risk for cardiovascular diseases : systematic review and meta analysis. Int. J. Geriatr. Psychiatry 22, 613–626 (2007).
3. Aboyans, V. et al. 2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases , in collaboration with the European Society for Vascular Surgery (ESVS). Eur. Heart J. 39, 763–821 (2018).
4. Chaikitpinyo, A., Panamonta, M., Wongswadiwat, Y. & Weraarchakul, W. Rheumatic and congenital heart diseases among school children of Khon Kaen , Thailand : declining prevalence of rheumatic heart disease. Asian Biomed. 8, 645–650 (2014).
5. Zühlke, L., Mirabel, M. & Marijon, E. Congenital heart disease and rheumatic heart disease in Africa : recent advances and current priorities. Heart 99, 1554–1561 (2013).
6. Agarwal, B. L. Rheumatic heart disease unabated in developing countries. Lancet 910–911 (1981).
7. Bruneau, B. G. The developmental genetics of congenital heart disease. Nature 451, 943–948 (2008).
8. Goldhaber, S. Z. & Bounameaux, H. Pulmonary embolism and deep vein thrombosis. Lancet 379, 1835–46 (2012).
9. Tapson, V. F. Acute Pulmonary Embolism. N. Engl. J. Med. 358, 1037–1052 (2008).
10. Lensing, A. W. A., Prandoni, P., Prins, M. H. & Büller, H. R. Deep-vein thrombosis. Lancet 353, 479–485 (1999).