Over the past 50 years, the numerous available pharmacological, surgical and instrumental therapies have been shown to improve symptoms, prevent or resolve complications, and increase survival and quality of life for the majority of patients with cardiomyopathy
In any case, the choice of therapy varies from individual to individual. The choice must be made by an experienced cardiologist, based on the symptoms and evaluation of numerous elements, including age, symptoms, ECG, ventricular function and especially the specific underlying disease that caused the cardiomyopathy.
Particular attention should be paid to the combinations of several drugs, due to their side effects which can be accentuated.
Drugs and devices commonly used in the therapy of Cardiomyopathies are listed here.
It is usually prescribed to regulate heart rate and blood pressure, reduce symptoms, prevent complications, such as arrhythmias and disease progression.
Beta-blockers slow the heartbeat and reduce its contraction force, but at the same time protect the heart, especially if it is dysfunctional. In medical practice they are also widely used for other types of heart disease and for arterial hypertension. Their dosage must be established on the basis of various factors, mainly heart rate, which must be maintained during the day between 50 and 65 beats per minute; if the heart rate is excessively slow (below 50 beats per minute) it is advisable to contact the cardiologist again.
In HCM they contribute to reducing angina, theshortness of breath, palpitations and particularly, obstruction. In DCM they have been used for over 30 years, with excellent results, especially in patients with a relatively high heart rate of over 80 beats per minute.
One of the main contraindications is cardiac asthma or asthmatic bronchitis, but also psoriasis and cold intolerance of hands and feet (e.g. chilblains).
There are many types of beta-blockers, with different effects based on dosage and potency. Due to their specific characteristics, Bisoprolol or Carvedilol is preferably used for DCM and patients with heart failure, Nadolol is preferably used for HCM, Atenolol for arterial hypertension.
Diltiazem and Verapamil are calcium channel blockers that are now rarely used in HCM to reduce angina. They have little effect on the obstruction. When combined with beta-blockers they can cause an excessive slowing of the heart rhythm and their effects must therefore be carefully monitored.
For patients with paroxysmal or permanent Atrial fibrillation (AF) and patients with large LV dilatation or ventricular aneurysm, anticoagulant drugs are indicated, in order to prevent thrombus formation. Vitamin K antagonist drugs ("Coumadin" or "Sintrom” brand names) need monitoring of the dosage and effectiveness by measuring the INR value, which must be between 2 and 3, every 20-30 days and more often if values are very variable.
For over 10 years, new oral anticoagulants have also been used (NAOC: Dabigatran, Rivaroxaban, Apixaban, Edoxaban) equally effective, which do not require INR monitoring, have a significantly higher cost and have severe limitations to be prescribed by the NHS.
When there is heart failure, even of a mild degree, there is an indication for diuretic drugs, which increase the leakage of accumulated liquids, with the emission of large amounts of urine.
The use of diuretics can reduce sodium and potassium levels, which should be periodically monitored.
(ACE inhibitors, Angiotensin inhibitors Sartans, Neprilysin inhibitors ARNI)
For many years these drugs have been used successfully in decompensation therapy. Dosages are variable. Much attention must be paid to the simultaneous adequate intake of fluids (water, juices, etc.) in order to avoid significant lowering of blood pressure (hypotension). They are contraindicated in obstructive HCM, even if the patient has associated arterial hypertension.
These drugs (Spironolactone, Canrenoate and Eplerenone) have the function of avoiding the reduction of potassium levels, which may promote even threatening arrhythmias.
Their combination with vasodilator drugs requires careful monitoring of potassium.
It is a selective inhibitor of the late sodium current, which has shown remarkable anti-ischemic efficacy in patients with coronary artery disease. In addition to the anti-ischemic effect, Ranolazine showed a good antiarrhythmic effect, documented in some patients with HCM and in laboratory studies on heart cells extracted during myectomy surgery. It is used to control symptoms of angina at rest in non-obstructive HCM.
Amiodarone is the most widely used antiarrhythmic drug in HCM, especially after the age of XNUMX. It is very effective in controlling arrhythmia, both atrial (AF) and ventricular (SVT) although it has low efficacy in preventing cardiac arrest and sudden death. However, it has several potential side effects, including hypersensitivity of the skin to sunlight, so it is necessary to either avoid sun exposure or use a high protection sunscreen. Also, periodic monitoring of thyroid hormones (FTXNUMX and TSH), should be carried out every 4, maximum 6 months, to identify a reduction (hypothyroidism) or an increase (hyperthyroidism) in thyroid function.
Amiodarone can be combined with beta-blocking drugs, but heart rate should be carefully monitored to avoid excessive slowing of the heart rate (bradycardia), unless there are pacemakers or TV-ICD.
When using Amiodarone, potassium values should always be above 4 mEq / L.
Other antiarrhythmic drugs used, more rarely, are Sotalol, Propafenone e flecainide, but their effects must be carefully monitored. These drugs should never be combined with Amiodarone.
The therapy Antiarrhythmic therapy in patients with cardiomyopathy must be decided by an experienced cardiologist and its positive or negative and / or potentially harmful effects must be carefully evaluated.
Cardioversion of arrhythmias
Atrial Fibrillation (AF) and the far more serious episodes of Sustained ventricular tachycardia (SVT) or Ventricular fibrillation (VF) can be interrupted with an electric discharge to the chest with restoration of the sinus rhythm, by means of an External defibrillator, under transient anesthesia, or by an Implantable defibrillator (ICD).
The discharge of the External defibrillator is almost always effective in restoring normal rhythm; it is essentially risk-free, with the necessary precautions.
Specific medical therapy
Hypertrophic Obstructive Cardiomyopathy
Disopyramide is a drug, initially used as an antiarrhythmic, which may be useful in controlling obstruction in HCM, often in combination with Beta-blockers. It can improve symptoms, at least temporarily. Its effectiveness is greater in elderly people.
Mavacamten is a new drug, still being tested, which modulates the contraction force of the heart cells, reducing the activation of myosin. Preliminary results seem to indicate good efficacy in obstructive HCM.
When obstructive HCM is present, certain medications are contraindicated: Vasodilators, digitalis derivatives, and diuretics, which can increase the obstruction.
For about 20 years it has been possible to intravenously administer the enzyme α-galactosidase every 2 weeks, more effective especially in the non-advanced stages of the disease and at an adequate dosage (XNUMX mg / kg). For some years now, oral therapy has also been available with "Migalastat”, to be taken daily and used when the enzymatic activity is only reduced and not absent. Several new therapies are also being studied, including gene therapy.
Until a year ago, therapy was only aimed at reducing symptoms and avoiding events.
In Transthyretin ATTR Amyloidosis, both genetic and "senile", the efficacy of a new drug has recently been demonstrated ("Tafamidis”), which acts by stabilizing the amyloid substance deposited between heart cells, slowing the accumulation and progression of the disease.