Medicare Approves ICDs as Primary Prevention for Sudden Cardiac Arrest

February 5, 2005 - A new rule by the Centers for Medicare & Medicaid Services (CMS) on a device vice president Dick Cheney made famous should make Barnes-Jewish Hospital''s clinical cardiac electrophysiology lab busier in 2005.

In 2001, America learned about the Implantable Cardioverter Defibrillator (ICD) -- a palm-sized device implanted near the shoulder that electrically shocks a patient''s heart out of life-threatening arrhythmias -- when doctors implanted the device in Cheney because they believed he was at increased risk for developing a fatal heart rhythm based on the extent of damage to his left ventricle caused by a heart attack.

Under previous CMS rules, Medicare covered the device only for patients who were fortunate enough to survive a life-threatening ventricular arrhythmia or for patients like Cheney who were at risk based on the extent of heart damage caused by a previous heart attack.

However as of January 20, Medicare expanded primary prevention coverage for ICDs to include patients who have significant damage to their left ventricle from a heart attack or from other causes of heart muscle damage. Heart attacks are caused by a blockage in one or more of the heart''s arteries. Other causes of heart muscle damage include untreated hypertension, heart valve diseases, virus infections and toxic substances.

"Sudden cardiac arrest is the most common way people die of heart disease and it''s preventable with this device," says Michael Cain, MD, chief of cardiology and an electrophysiologist at the Washington University Heart Care Institute at Barnes-Jewish Hospital.

Physicians usually assess the extent of heart muscle damage by measuring the left ventricular ejection fraction or "EF". The normal ejection fraction is 60 to 70 percent and sudden cardiac arrest occurs from a lethal heart rhythm disorder that originates in the area of heart muscle damage.

"Our decisions about defibrillators are based on the ejection fraction," says Bruce Lindsay, MD, chief of electrophysiology at Barnes-Jewish Hospital and Washington University School of Medicine. "A person''s EF is the amount of blood the heart pumps out with each heart beat and when the ejection fraction gets down to less than 30 to 35 percent, the risk of a cardiac arrest increases substantially."

If a patient has a life-threatening ventricular arrhythmia, the ICD detects it in seconds and delivers a shock or rapid burst. So, if someone has a cardiac arrest on the street, the likelihood of being successfully resuscitated from a bystander doing CPR and transported to a hospital in time is 20 to 30 percent. Only a fraction of those who make it to the hospital are discharged alive. If cardiac arrest occurs in a patient with an ICD, the ICD will terminate the arrhythmia.

CMS''s decision is based on evidence from a recent study, Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), and three earlier studies that show people with heart failure but no history of heart attacks are just as susceptible to sudden cardiac arrest. SCD-HeFt followed more than 2,500 patients who had a left ventricular ejection fraction less than 30 percent for six years and showed that ICDs reduced mortality rates in this group of patients by 23 percent.

"This means CMS''s decision should improve death rates by 25 to 30 percent and when you apply that to the national average that''s several thousand lives a year," says Dr. Cain.

CMS estimates nearly 500,000 more Medicare recipients across the country would be eligible for an ICD, with at least 25,000 more Medicare patients nationwide expected to receive ICDs in the first year of coverage.

"We''ve implanted thousands of these devices since the mid-80s as a secondary treatment and by Medicare expanding that patient base we should see a substantial increase in the number of patients who will benefit from this life saving therapy," says Dr. Cain.

Washington University electrophysiologists at Barnes-Jewish Hospital have been implanting ICDs since 1985 and implant about 300 per year along with 250 pacemakers. The group was one of the first centers in the country to offer arrhythmia ablation procedures and one of the first to implant ICDs. In addition, the incidence of ICD infections at Barnes-Jewish Hospital is less than one percent, well below the national average.