ORLANDO, FLA. -- After analyzing data of more than 56,000 U.S. patients who arrive at emergency rooms with heart attack symptoms, researchers from a Duke University Medical Center-led patient registry have found that almost two out of three patients did not receive a class of clot-inhibiting drugs within the first 24 hours of symptoms, despite the fact that clinical trials that have proven that the drugs save lives.
The drugs in question, known as glycoprotein (GP) IIb/IIIa inhibitors, are agents that block receptors on blood platelets preventing them from forming clots. Large multi-center trials have proven the inhibitors' effectiveness in preventing deaths in patients with chest pain if administered within 24 hours of being seen in the hospital.
The scientists' analysis of current hospital practices in the U.S. also revealed that other proven drug therapies, as well as the early treatment by a cardiologist and the aggressive use of invasive procedures such as angioplasty, are also underutilized. Improving the usage of all these evidence-based therapies can help reduce the mortality rates for these patients, the researchers said.
The results of the current analysis were presented today by James Hoekstra, M.D., chairman of the department of emergency medicine at Wake Forest University School of Medicine, Winston-Salem, N.C., at the 76th annual scientific session of the American Heart Association.
"Acting quickly with therapies that have been shown to be effective can save lives," Hoekstra said. "The ultimate goal for improving patient outcome is to use protocol-driven care. If we stick with the guidelines and utilize all the proven therapies within the first 24 hours, our patients will do better."
For their analysis, the Duke team consulted the nationwide quality improvement initiative dubbed CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes with Early Implementation of the ACC and AHA Guidelines). CRUSADE is coordinated by the Duke Clinical Research Institute, with Duke cardiologists Eric Peterson, M.D., and Matthew Roe, M.D., serving as principal investigators.
Since 2000, CRUSADE has been gathering clinical data from more than 400 U.S. hospitals. The program provides regular feedback to hospitals with the ultimate goal of improving adherence to treatment guidelines established by the American Heart Association (AHA) and the American College of Cardiology (ACC).
In their analysis of the medical data of 56,264 patients in the CRUSADE registry who received GP IIb/IIIa inhibitors between January 2001 and June 2003, the researchers found that only 36 percent received the drug within the first 24 hours. For those who received the drug early, the in-hospital death rate was 2.7 percent, compared to 4.7 percent for those who didn't.
Interestingly, the patients who did not receive this medication within the first 24 hours tended to be older, to have additional health problems, and to have more cardiovascular disease, said the scientists.
"This is one of the paradoxes that we see in medicine, that the patients who would benefit the most from an effective therapy are not receiving it," Peterson said. "Evidence from CRUSADE and other national efforts has consistently demonstrated that proven therapies are not being used as often as they should, with the GP IIb/IIIa inhibitors having the lowest usage."
Hoekstra said that the patients who did the best were treated aggressively as soon as possible.
"As soon as the patient is identified, we need to treat aggressively with the whole package -- heparin, aspirin, beta-blockers, GP IIb/IIIa inhibitors and catheterization if appropriate," Hoekstra said. "The timeline of care for these patients is critical. In the old days, many of these patients would be sent from the emergency department to the cardiac care unit to 'cool off' for a few days.
"Now we know that the key is to start these protocols that have been proven effective right away in the emergency room," Hoekstra continued.
CRUSADE continuously gathers data on treatments for patients with non-ST-segment elevation MI and unstable angina (collectively known as non-ST-segment elevation acute coronary syndromes - NSTE ACS).
While similar studies have been conducted on patients suffering from acute ST-segment elevation MI, CRUSADE targets a different, but just as important, group of high-risk heart patients. CRUSADE patients will typically arrive at emergency rooms with chest pain (angina), but often will not have telltale signs of an MI on the initial electrocardiogram and may only be diagnosed with a heart attack when the results of initial troponin testing are reported a few hours later.
Ultimately, CRUSADE aims to include more than 100,000 high-risk NSTE ACS patients. It is the first study to collect this kind of data on so many patients with the goal of actually changing practice patterns and improving clinical outcomes, the researchers said.
"Efforts such as CRUSADE can help us better understand which patients are not receiving appropriate care," Peterson continued. "With this knowledge, perhaps we can then start to remove the barriers keeping patients from receiving proven care."
A clue to the treatment deficit was provided by the results of a survey of 330 of the more than 400 hospitals participating in CRUSADE, said Peterson. The survey revealed that only 31 percent of the hospitals' emergency departments had formal protocol for the use of GP IIb/IIIa inhibitors, and that only 21 percent of emergency room physicians routinely administered the drug without a cardiology consultation.
"The survey indicates that emergency room physicians did not feel empowered to begin this treatment without the go-ahead from a cardiologist," Peterson said. "It is very much analogous to the early days of thrombolytic therapy - it took some time for emergency room and primary care physicians to feel comfortable using these drugs."
CRUSADE is funded by Millennium Pharmaceuticals, Cambridge, Mass., Schering-Plough Corp., Kenilworth, N.J., Bristol-Myers Squibb, N.Y., and Sanofi Pharmaceuticals, N.Y.