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021$&2&$5',27+25$&,&&(17(5 Patient information Valvular heart disease Pathologies, diagnosis and treatment 1 Valvular heart disease The term valvular heart disease covers all diseases that affect the valves of the heart. Heart valves are soft tissue structures between the four heart cavities, two on the left (the mitral and aortic valves) and two on the right (the tricuspid and pulmonary valves). Their function is to prevent the blood flowing back into the cavity it came from. Sometimes, one or more of these valves fails to work properly because of one of two types of problem: • Valve stenosis (or narrowing) prevents the valve from opening fully which obstructs blood flow. • Valve regurgitation (or leaky valve or valve incompetence): when the valve cannot close properly, it allows blood to leak backwards. The same valve may be affected by both these problems simultaneously. Pulmonary valve (open) Mitral valve (closed) Tricuspid valve (closed) Aortic valve (open) Valvular heart disease 2 The most common forms of valvular heart disease These days, the most common valve problems in adults are aortic stenosis and mitral insufficiency. Other problems include aortic insufficiency, tricuspid insufficiency and mitral stenosis. Disease of the pulmonary valve is rare What are the causes? Causes vary according to the valve affected: • Age-related degeneration (aortic stenosis, mitral insufficiency and aortic insufficiency), • Acute rheumatic fever (mitral and tricuspid stenosis), a birth defect, • Infection, i.e. endocarditis (all valves), • Diseases that affect heart muscle (heart failure, myocardial infarction) can impair valve function. How does valvular heart disease develop? Without treatment, valvular heart disease tends to lead to dilatation of the atria or ventricles because of the extra work solicited from the heart. The symptoms are shortness of breath due to increased pressure in the lung (pulmonary oedema), faintness with loss of consciousness possible, palpitations and episodes of cardiac insufficiency. 2 How is valvular heart disease discovered? •S ymptoms: shortness of breath on exertion (and at a more advanced stage, at rest), angina pectoris, loss of consciousness (aortic stenosis), palpitations, pulmonary oedema, heart failure. • Auscultation: a murmur (stenosal or regurgitant), irregular heartbeat. Sometimes, the absence of symptoms is not in contradiction with the severity of the disease. • Accurate diagnosis depends on echocardiography using a probe either placed on the chest (transthoracic ultrasonography) or inside the oesophagus (trans-oesophageal ultrasonography with local anaesthesia). Echocardiography: - Confirms the diagnosis of valvular heart disease, be it stenosis or insufficiency, - Measures the surface area of the valve, - Estimates the severity of the problem, - Measures the pressure gradient across the valve, - Assesses the impact of the valvular disease on dilatation of the cavities and the ability of the heart muscle to contract. For further details, see the “Echocardiography” information sheet. The criteria used to determine if surgery is indicated are very precise and are based on well-defined measurements. Once it has been decided to operate, the check-up will be complemented with: • Coronary angiography In a preoperative check-up to investigate valvular heart disease, coronary angiography is an invasive examination that allows imaging all the coronary arteries and Valvular heart disease 3 identifying any areas that have been narrowed by atheromatous plaque. If necessary, the results can help with the decision about whether or not to treat coronary arteries. The examination is performed in a specially equipped radiology unit. This examination requires the injection of a contrast medium opaque to X-rays. This makes it possible to image all the coronary arteries. Like any invasive method, coronary angiography has risks. These are low but patients ought to be aware of them: • Allergic reaction. • Complications at the puncture point in the artery. • Cardiac and vascular complications. • CT scan (in some cases) In young patients, if perfectly normal coronary arteries are found during this examination, coronary angiography can be avoided. A CT scan can also give information about the shape and size of the aorta coming out of the heart when the aortic valve is involved (aortic aneurysm). For further details, see the “CT Scan” sheet. • Magnetic resonance imaging Serious complications are very rare: by way of reference, the results of a study of a large number of patients, published in a medical journal, found a risk of death of 0.8/1,000, a risk of neurological problems (notably paralysis) of 0.6/1,000 and a risk of myocardial infarction of 0.3/1,000. Other less severe complications were reported, with an incidence under 1%. For further details, see the “Coronary artery disease” sheet. Since 2002, this method has been used at the Monaco Cardio-Thoracic Center, to examine the heart muscle and detect fibrosis or evidence of past infarction. For further details, see the “MRI” sheet. 3 How is valvular heart disease treated today? After drug treatment, invasive therapy may be indicated, depending on the condition of the valves, the impact on heart muscle and the symptoms: • Surgical repair or valve replacement, • In certain conditions, a percutaneous procedure (Valvuloplasty of the mitral valve, or Transcatheter aortic valve implantation - TAVI) Surgical repair remains the reference treatment for valvular heart disease. 1 - Surgery Once it has been decided to operate, the surgical possibilities are: • Repair of the valve (the mitral, tricuspid or occasionally aortic valve), • Or replacement of the valve with either a mechanical or a biological prosthesis. Valvular heart disease 4 Valve repair Repair is the treatment of choice for mitral insufficiency, used whenever possible: • Commissurotomy (incision of fused commissures) is only carried out for mitral stenosis secondary to rheumatic fever if the valve is still flexible and the heart rate is regular (sinus rhythm), preferably in children and young women of child-bearing age. • Plastic repair of the mitral valve may be indicated for mitral insufficiency. In this type of procedure, the abnormality of the papillary muscle, valve or annulus is repaired, but the original valve is conserved (plastic surgery inside the heart). A prosthetic annulus is always implanted to correct deformation of the mitral opening. • Tricuspid valve repair for functional tricuspid insufficiency due to dilatation of the right ventricle. • In some cases of simple tricuspid insufficiency, genuine plastic surgery can repair the valve by enlarging it. • If there is an aneurysm of the ascending aorta, the aortic valve can sometimes be repaired. Valve replacement Prosthesis can be implanted in the orifice of the aortic or mitral valve and, less often, the tricuspid valve. Two or even three heart valves can be replaced. Whether or not to undertake replacement and choice of the type of prosthesis (mechanical or biological) are decided, in concert with the patient, on the basis of a series of different criteria: • The patient’s age, • Presence or absence of an irregular heartbeat necessitating anticoagulant therapy, • Advantages and risks of long-term anticoagulant treatment (anti-Vitamin K), • The condition of the heart muscle tissue, • The patient’s lifestyle. Mechanical valves consist of a cage made of a metal-carbon alloy with a base that can be fixed on the annulus of the valve, together with a mobile system, either a disk or flaps. Their advantage is solidity (Starr® valves implanted 30 years ago are still working perfectly). The disadvantage is that patients must take anticoagulant drugs all their lives; if these drugs are too powerful, there is a risk of bleeding and if they are not powerful enough, the risk is of thrombosis and embolism (clot formation). Biological valves or bioprostheses are made of a Dacron®-coated Two-flap mechanical valve metal frame holding three biological tissues, either from pigs or made from the pericardium of young cattle. The bioprosthesis has a metal ring lined with a silicone cushion which can be inserted on the annulus of the valve. New “stentless” bioprostheses no longer have a rigid ring and are mounted on flexible tissue in Dacron which cuts down mechanical stress and should prolong the device’s lifetime. The great advantage of bioprostheses is Bioprothesis that they preclude the need for lifelong anticoagulant treatment in the absence of complete arrhythmia. However, they may deteriorate after some fifteen years, necessitating a follow-up intervention. Bioprostheses are preferred in the elderly, in women who want to Stentless conceive a baby, and bioprosthesis especially in those in whom effective, closely monitored anticoagulant therapy is contraindicated or impossible. However, they can be used in physically active patients of under 50 with a heart in good condition, Valvular heart disease 5 who do not want long-term anticoagulant therapy and who accept the idea that a follow-up intervention may well be necessary after about fifteen years. The older the patient, the slower is the deterioration of bioprostheses. Before the intervention On admission, you should give the doctors and nurses all the medical documents that you have in your possession, including radiographs and the results of any stress and laboratory tests. You will undergo a biological check-up and the care-providing team will explain how to prepare for the operation (showering and mouth hygiene) to prevent infection. The region to be incised will be thoroughly depilated and disinfected. How will the operation proceed? With the patient under general anaesthetic, an incision (sternotomy) is usually made in the middle of the sternum or a mini-sternotomy (aortic valve). A heart-lung by-pass machine is used to circulate blood through the body and make it possible to work inside a “dry” heart. During the intervention, the heart muscle is protected by general and local hypothermia, and stopped by cardioplegia. The surgical procedure lasts about three or four hours (depending on the complexity of the case). Intensive care After surgery, patients spend about 48 hours in intensive care. Patients are put on assisted ventilation for the first few hours after which they are gradually taken off until the tracheal tube can be removed. Drugs are administered to relieve pain and fluids are infused intravenously to prevent dehydration. Temporary thoracic tubes are left in place for a few days to drain serum and blood from the operative site. A small percentage of patients will need a blood transfusion. Oral feeding is usually resumed the day after the operation. Discharge from intensive care After about 48 hours, most patients are allowed to get up and walk around. Regular sessions of physical therapy help with the recovery of functional independence and normal breathing. Patients’ ECGs are permanently monitored (remote monitoring). What are the risks of valve surgery? Like any kind of surgery, valve surgery is associated with some level of morbidity and mortality. The risk is assessed by the medical team (the cardiologist, surgeon and anaesthetist) on the basis of the state of the patient’s heart and general condition. Complications may onset during or immediately after the operation. Some are common like abnormal heart rate (arrhythmia, bradycardia) which might necessitate the implantation of a pacemaker. Others are rarer like postoperative infection (less than 2% in the experience of C.C.M.) or neurological complications (less than 1.5%). These risks will depend – as the patient and his/her family are told – on the specific features of the patient and the disease but they are far lower than the risk associated with spontaneous progression of the disease. This is why surgical treatment is proposed. Valvular heart disease 6 What happens when you are discharged from the Center? Long-term surveillance of patients with a replacement valve You will be discharged either to your own home or, more commonly, to a specialist convalescence facility (according to the patient’s condition and wishes). As a rule, physical recovery is rapid. Driving and sexual activity can be resumed as soon as consolidation of the sternum has been obtained. In most cases, replacement of the defective valve will result in significant improvement, especially less or no more shortness of breath on exercise. The main limitation to the resumption of normal activities is healing of the sternum. As with any broken bone, it may take 6 – 12 weeks to obtain definitive consolidation and, during this period, any activity that might put the rib cage under significant stress must be avoided. Return to work When a patient can go back to work will depend on his/her recuperative capacities and the levels of stress and physical activity associated with his/her job. Your surgeon and cardiologist will be able to help you decide when to return to work. Will I need physical therapy? A programme of cardiac rehabilitation can speed up recovery and help you get back to your normal daily activities sooner. In addition, you will be given advice and recommendations about lifestyle changes, covering diet, weight loss, physical exercise and sports. During this period, you will be told about anticoagulant therapy and what carrying an implant means. The cardiologist and the surgeon will help you match the rehabilitation programme to the condition of your heart and your overall state of health. Regular surveillance is indispensable by: • your general practitioner, • your cardiologist, • and your dentist. > You should see your general practitioner once every two or three months, to check: • The prosthesis by auscultation, • Anaemia, • Infection • Efficacy of the anticoagulant treatment. > You should be monitored by your cardiologist once every six months, including electrocardiography and echocardiography. If it is suspected that the prosthesis is not functioning properly, further investigation may be required (e.g. MRI). > You should see a dentist every six months without fail and prophylactic antibiotics ought to be taken before any dental procedure. Remember to tell your dentist this. “I am on anticoagulants”. Remember to tell your professional health care providers! Valvular heart disease 7 The anticoagulant drug The anticoagulant drug administered is an Anti-Vitamin K (Sintrom®, Préviscan®, Coumadine®…) : • Patients with an implanted mechanical valve have to take it all the time for the rest of their lives. • After mitral plastic surgery and the implantation of a biological prosthesis, it must be taken for three months. • If the patient has arrhythmia, anticoagulant therapy should be continued until the arrhythmia regresses. If a mechanical valve has been implanted, anticoagulant therapy must never be stopped for any reason. > The efficacy of anticoagulant therapy is monitored via International Normalised Ratio (INR) measurements: • between 2 and 3 if there is arrhythmia and after a plastic procedure or implantation of a biological prosthesis, • between 3 and 4 for a mechanical mitral valve. At the beginning of the course of treatment, INR is checked every 8 days, then every 15 days, and then every month until it appears to be stable. If it is unstable, it should be checked more often and it should also be checked a few days after the dosage of the Anti-Vitamin K is changed. Doses and laboratory test results should be recorded in an Anticoagulant Treatment Record. > Overdose may induce bleeding, e.g. prolonged bleeding from a shaving cut or after brushing of the teeth, easy bruising. INR should be checked with a view to reducing the dosage. > Some medications should be avoided because they either potentiate anticoagulant activity (tetracycline, aspirin, anti-inflammatory drugs) or inhibit it (barbiturates). > Intramuscular injection must be avoided in patients on anticoagulant therapy. > Some foodstuffs may modulate anticoagulant activity: • Do not eat more than one portion a day of foods rich in Vitamin K, e.g. tomatoes, lettuce, spinach, cabbage, broccoli and Brussels sprouts; • Limit alcohol consumption to 2 units a day. Prevention of infectious endocarditis Carriers of a prosthetic heart valve are susceptible to a serious complication in which bacteria colonise the implanted device; this is referred to as infectious endocarditis. This complication – which is always serious – manifests as chronic, low-level fever and can lead to damage to the valve. The source of the bacteria is often a dental infection. Thus, the danger of infectious endocarditis necessitates: > Watching out for any fever and notifying your doctor; > Assiduous treatment of any infection – dental, lung, throat, urinary tract, skin – even a minor one; > Prophylactic antibiotic coverage before any invasive procedure, such as dental care. Keep your dentist informed about your heart disease. > Rigorous mouth hygiene and teeth in perfect condition. Valvular heart disease 8 Although prosthetic valves are not perfect and require close surveillance, permanent anticoagulant treatment in many cases and special measures to prevent infectious endocarditis, they nevertheless let patients live and work normally as long as they are implanted in time, before the cardiac muscle tissue has sustained irreversible damage. 2 - Special cases Percutaneous treatment of the mitral valve To correct mitral stenosis following rheumatic fever in young patients in whom the valve is flexible and the heart rate regular, percutaneous treatment can often put off the need for surgery for several years. These cases are particular and limited in number. Candidates for this type of treatment will be given a special information sheet about this procedure. Percutaneous artificial aortic valve implantation This technique applies to patients with severe aortic narrowing who cannot be operated on or in whom surgery carries a high risk – usually the elderly or patients with a history of surgery in the past. Edwards-Sapien valve This alternative to surgery permits replacement of a defective aortic valve with a bioprosthesis using one of two methods: • cardiac catheterisation in which the artificial valve is transported to the heart via the femoral artery, • or implantation in a minimally invasive procedure, through a tiny opening in the chest over the apex of the heart below the left breast (a transapical approach). This technique is still being assessed and, according to current cardiology guidelines, it should only be considered for a given patient after two surgeons have decided that surgery is contraindicated. After deliberations between physicians and surgeons, candidates for this type of treatment will be given a special information sheet about the procedure. Dilatation of mitral valve Bibliography Société Française de Cardiologie Fédération Française de Cardiologie © MONACO CARDIO-THORACIC CENTER - december 2012