Controversies about heart failure treatment
In recent years, several controversies have moved to the forefront of treatment for heart failure.
Controversy #1: Anticoagulant medicines
Doctors sometimes notice that medicines used as treatment for one condition can also be helpful in treating another. Anticoagulant medicine is one example. The potential benefits and complications of anticoagulants are the root of the controversy on using it for people with heart failure.
What are anticoagulant medicines? Anticoagulants make your blood thinner and less likely to clot. Doctors have used anticoagulants for years for people who have had heart attacks. In people who have had a heart attack that affected the front wall of the heart (anterior MI), anticoagulants reduce the risk of forming a blood clot that could then break loose and cause a stroke or another heart attack. The most often-used anticoagulant is a medicine called warfarin (such as Coumadin).
How do anticoagulants help heart failure? In heart failure, your heart is not able to pump blood effectively. This often slows your blood flow down and prevents blood from moving through your muscle at a normal speed. This slower motion may cause blood to clump together and form small clots. These clots are extremely dangerous because they can travel to other areas of the body and block the flow of blood, causing a stroke or heart attack.
Warfarin has had mixed results when used to prevent blood clots from forming in people with heart failure. Some studies have found that it reduces the risk of clot formation; other studies show no benefit.
What's the problem with anticoagulants? Warfarin (and other anticoagulants) may cause significant bleeding. You could bleed freely for several hours even after a relatively minor injury or cut because warfarin makes it difficult for your blood to clot. As a result, it increases your risk of serious internal bleeding.
Most doctors agree that people with heart failure and the following conditions should take some type of blood thinner, such as warfarin:
- Atrial fibrillation
- A recent heart attack with damage to the front of the heart
- A mechanical heart valve replacement
- A blood clot in the heart
However, doctors do not agree on whether people with moderate to severe heart failure who have not had a blood clot problem should take a blood thinner.
Controversy #2: Antiarrhythmic agents
Some people with heart failure develop abnormal heart rhythms (arrhythmias). Arrhythmias can occur in either the upper heart chambers (atrial arrhythmia) or the lower, larger heart chambers (ventricular arrhythmia).
Three ventricular arrhythmias are fairly common in heart failure:
- Premature ventricular contractions (PVCs)
- Ventricular tachycardia
- Ventricular fibrillation
Doctors believe that ventricular tachycardia and ventricular fibrillation may be the reason why 30% to 70% of people with heart failure die suddenly after living with the condition for many years.
How do antiarrhythmic agents help heart failure? Some doctors believe that people with heart failure should take antiarrhythmic agents to prevent these deadly arrhythmias. Some of these medicines do appear to reduce the risk of ventricular tachycardia and fibrillation in people with heart failure.
What's the problem with antiarrhythmic agents? Three main issues further complicate treatment with antiarrhythmics:
- Some antiarrhythmic agents can make systolic heart failure worse.
- Drugs known as class I antiarrhythmics (such as quinidine, procainamide, and flecainide) have been shown to increase risk of death in people with heart failure.
- Despite their ability to prevent arrhythmias, no antiarrhythmic has actually been proven to lengthen the lifespan of people with heart failure. For example, in a recent study, amiodarone did not improve survival of people with heart failure.1
The possible side effects of antiarrhythmic agents must be compared with the possible benefits for people with heart failure who have never experienced an arrhythmia. Since antiarrhythmics have not been proven to increase the lifespan of people with heart failure, most doctors agree that the drugs should not be prescribed unless you have already experienced a serious arrhythmia.
An automatic implantable cardiac defibrillator (AICD) is a device that controls the heart rhythm and rate. An AICD may be implanted as an alternative or in addition to antiarrhythmic medicines such as amiodarone. A person must fulfill a number of criteria, such as having no other life-threatening illnesses, to get an AICD. For the appropriate people, doctors will likely use AICDs commonly in antiarrhythmic therapy. One study showed that AICDs are more effective at preventing death than amiodarone.1
Controversy #3: Pulmonary artery catheters
One result of heart failure is that blood backs up into your heart. This backup causes the pressure to increase throughout your heart and lungs.
What is a pulmonary artery catheter? Your doctor can measure the pressure inside your heart by using a special catheter that can be inserted in the intensive care unit or cardiac cath lab. Your doctor may thread a small tube (catheter) through a vein in your neck and into the main blood vessel that leads to your lung, known as the pulmonary artery. Once it has reached a point in the artery where it can't advance any farther, a balloon on the end of the catheter can be inflated to measure the pressure of blood inside your lungs beyond the catheter and to the left atrium within your heart. The catheter can also find out how much blood is being pumped with each contraction (cardiac output). The pulmonary artery catheter (PAC) can be left in your body for several hours or even days so that your doctor can monitor any changes in pressure within your heart after certain medicines are started.
How does a PAC help heart failure? It is important for your doctor to know the pressures inside your heart because high pressures often are signs of ineffective pumping by the heart. This information can be used to guide the choice of medicine to treat heart failure.
What's the problem with PACs? Some doctors feel that PACs are not needed because heart pressure can be estimated well enough by performing a thorough physical examination. These doctors think that it is not necessary to know the exact level of pressure within the heart and that other, less invasive tests can show how much blood is being pumped. In the ESCAPE trial, PACs did not affect mortality or the number of days a person with heart failure spent in a hospital.2
Use of a PAC may cause serious complications, including bloodstream infections, valve damage, bleeding inside the heart or lungs, and punctures of the heart or lung. Also, widespread use of PACs may be associated with an increased risk of death. In the ESCAPE trial, PACs increased the risk of infection, bleeding, and arrhythmia.2
Some doctors believe that information from a PAC is so useful in guiding treatment of heart failure that PACs should be used in everyone with moderate to severe heart failure. These supporters suggest that PACs are a huge help in choosing medicines and other interventions. Many doctors believe that the small risks associated with PACs are probably outweighed by the benefits of having an exact measurement of pressures inside the heart and lungs. However, results from the ESCAPE trial do not provide support for the routine use of PACs.
What do these controversies mean for me? Your doctor needs to consider everything about your health when treating your heart failure. This includes any other medical conditions you may have and how you may respond to treatment. Doctors and other health professionals sometimes disagree about certain aspects of treating heart failure. You should feel comfortable discussing each of these controversies with your doctor.
| Author: | Douglas Dana Robin Parks, MS | Last Updated: October 23, 2006 |
| Medical Review: | Adam Husney, MD - Family Medicine Caroline S. Rhoads, MD - Internal Medicine Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology | |
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