WHAT IS HEART FAILURE?

UNDERSTANDING HEART FAILURE

A progressive and complex disease

Heart failure is a progressive and complex disease initially effecting the heart muscle itself, however, the impact is eventually on all organs and tissues of the body. Initially, a person with heart failure may detect little or no change to their normal activities, or overall health, and may not be immediately recognized or diagnosed by a doctor.

Once diagnosed, there is no permanent cure for heart failure, although drug therapy has been shown to slow the rate of deterioration of the heart muscle. Over several years the condition worsens and the amount of blood pumped from the failing heart to the organs and tissues is reduced.

At this stage the patient becomes physically weaker, and capacity for most normal activity is limited by ‘shortness of breath’ caused by poor blood flow to the lungs.

The heart physically changes, becoming larger in overall size with thinner muscle walls, a process which tries to keep blow flow as high as possible, which is called ‘compensation’.

This continues for years until the heart can no longer compensate, when the patient is usually admitted to a hospital for specialist care by staff, drugs and equipment.

The patient is kept in hospital until the condition of the heart muscle, and of other organs such as the kidneys and lungs are is improved, and the heart can once again compensate. After one or two of these decompensation events the patient is considered to be in the final phase of the heart failure as a disease and is usually advised of the options for future care.

THE ULTIMATE SCENARIO

Transplants and other innovations

The failing heart can be replaced by a heart removed from another human who is dying, or has recently died, in a procedure called transplantation. Heart transplantation has a high rate of success, and patients with new hearts can live for many years with a very good quality of life.

However, heart transplantation is not available to all end stage heart failure patient’s due to the number of suitable hearts available, and also their own medical condition. Heart transplantation is not a perfect cure for heart failure as the recipient must take medication to prevent their immune system from rejecting the new heart.

Over the past thirty years alternatives to transplantation have developed which involve the implantation of mechanical pumps to either replace or assist the failing heart. A total artificial heart (TAH) replaces the pumping chambers of the failing heart when a patient is not suitable for a heart transplant or a transplant is not available. The number of TAHs implanted annually is low, partly due to the cost of the equipment and the complexity of managing the patient’s return to daily life, it is however, an alternative.

The alternative is a smaller rotary pump which is implanted in the pumping chamber of the failing heart, this is called a Left Ventricular Assist Device (LVAD). LVADs are implanted in thousands of patients worldwide and have the potential to support patients for over 10 years with a good quality of life.

Sometimes the quality of life of LVAD patients is limited by complications such as bleeding and blood clotting events which require rehospitalization.

Calon is developing the MiniVAD™ to reduce the occurrence of these complications.