Heart disease is the leading cause of death in America and it's also a major driver of health care costs.

A study by researchers at the University of Pennsylvania and the Philadelphia VA Medical Center found that newer medical devices are a major reason why heart care costs are rising dramatically. The researchers examined Medicare claims on patients between the ages of 65 and 84 with coronary artery disease and congestive heart failure from 2003 through 2006.

The study found that the inflation-adjusted cost of care for patients with heart disease rose from $12,160 in 2003 to $12,721 in 2006, a 4.6 percent increase. The average cost of care for heart failure patients rose from $17,153 in 2003 to $18,371 in 2006, a 7.1 percent inflation-adjusted increase.

While those numbers seem relatively modest, the impact of medical devices was significant and the cumulative cost of the new technology was huge.

The total cost increase attributed to new drug-coated stents – tiny wire scaffolds to prop open clogged heart arteries – was $3.3 billion. That was 73 percent of the total growth in the cost of caring for coronary artery disease among these Medicare beneficiaries.

And so-called implantable cardioverter defibrillators (ICDs) – devices that shock the hearts of patients back into correct rhythm – added $774 million to the cost of heart failure care among these Medicare patients. ICDs accounted for 15 percent of the total annual growth in the cost of heart failure among Medicare beneficiaries between 2003 and 2006, the study found.

The study was presented on Thursday, May 20 at the American Heart Association's Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke 2010 Scientific Sessions in Washington, D.C.