One of the primary goals for treating coronary artery disease is to keep the patient's blocked vessels open. In what has become a common procedure for removing blockages, a small balloon at the end of a catheter is inserted in the coronary arteries and inflated, compressing the atherosclerotic plaque so that blood flow can be restored. This procedure is called a percutaneous transluminal coronary angioplasty, or PTCA.
To decrease the risk of restenosis, or the reformation of a blockage at the site of the angioplasty, over half of PTCAs also involve the insertion of a slotted, stainless steel tube, called a stent, to keep the vessel open. Several studies have shown the need for subsequent revascularization procedures to be reduced with the use of stents. That's pretty good news when one considers that coronary heart disease is the cause of 20% of all deaths annually.
In addition, new drugs have been developed that inhibit blood clotting by binding with glycoprotein IIb/IIIa receptors, which represses the pile-up of platelets. ReoPro was approved for this purpose in 1994 and studies have found it reduces the risk of death for PTCA patients. However, most of those patients do not receive ReoPro due to its prohibitive cost--nearly $1,500 per treatment.
Two other GP IIb/IIIa inhibitors, Aggrastat and Integrilin, were approved in 1998. They are moderately less expensive than ReoPro.
In another of Solucient's ongoing series of clinical research studies, researchers examined the use of stents and GP IIb/IIIa inhibitors for PTCA patients to determine what hospitals were more likely to use these treatments and with what results. They discovered that hospitals that have made the 100 Top list have superior PTCA outcomes, in terms of lower rates for subsequent revascularization procedures, than institutions that didn't make the list.
Furthermore, Solucient's study shows that the rates of use of stents and the drugs ReoPro, Aggrastat and Integrilin among 100 Top Hospital winners and nonwinners are remarkably different, despite the fact that these are the treatments recommended for PTCA patients by leading heart specialists.
"The reason the American College of Cardiology and others recommend the use of stents and these drugs is that science shows there will be better outcomes for patients if they receive them," says Dave Foster, epidemiologist and assistant vice president of research at Solucient. "Yet, when we go into the real world, it's not always occurring. What we want to find out is, how does efficacy in terms of a clinical trial setting correspond with effectiveness in the real world?"
The answer is that the best hospitals are more likely to use stents and ReaPro and the new drugs, Foster says. They also have lower rates for subsequent revascularization procedures than nonwinners.
There is a stepwise increase in the adjusted likelihood of receiving a coronary artery stent based on the number of years a hospital has won the national 100 Top Hospitals award. All winners were 4% more likely to use stents than nonwinners and hospitals who received the award two or more years were 6% more likely to use them. The likelihood of stent use over peer hospitals jumped to 21% for three-year or more winners and was 36% at hospitals that have won the honor four or more years.
For PTCA patients who received GP IIb/IIIa inhibitors, similar results were discovered. The likelihood of receiving ReaPro was highest among winners who received the 100 Top Hospital honor three or more times, followed by one- or two-year winners, and was lowest in the reference group, the study found. Patients in top-performing hospitals were more likely to receive one of the drugs in PTCAs where no stent was used. The reverse was true for patients at the peer hospitals.
Even though top hospitals used these expensive technologies more than nonwinners, the Solucient study found they maintained lower costs than the reference facilities. Three-year and more winners had average adjusted PTCA charges of $24,483 while reference hospitals
The stent portion of the study includes data from 29,145 patients at 1,065 hospitals, using the 5% HCFA Standard Analytical Files for 1996 through 1998. To analyze the use of GP IIb/IIIa inhibitors, Solucient researchers used 1998 International Classification of Clinical Services data from 59 hospitals, including 28 top 100 winners.
"It's nice to extrapolate the scientific findings to find similar real-world patterns," Foster says. "The question is: Why are there such variances in these practices?"