Study Finds Latin American Heart Patients Receive Less Treatment than North Americans and are Nearly Twice as Likely to Die
BARCELONA, Spain - A new analysis of data gathered from an international drug study shows that patients in Latin America were treated with a more conservative approach and were nearly twice as likely to die within a month of being hospitalized for heart problems than were patients treated in North America.
The study also found that the Latin American patients received far fewer diagnostic procedures and only half as many angioplasties and cardiac bypass surgeries as did similar patients treated in the United States and Canada.
A team of international investigators, led by the Duke University Medical Center in Durham, N.C., prepared the findings for presentation at the annual meeting of the European Society of Cardiology.
Their analysis was done using information gathered on 585 patients treated at 72 hospitals in eight Latin American countries and 4,358 patients treated at 307 hospitals in the United States and Canada during a clinical trial called PURSUIT ("Platelet glycoprotein Iib/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy trial"). The study tested the use of Eptifibatide, a class of "super aspirin" drugs that help stop blood clots from forming. Patients were enrolled if they had chest pain or tests that indicated they were suffering from a heart attack or would probably soon have one.
"From what our study tells us, hospital physicians in Latin America take a much more conservative approach to treating patients with a heart attack than do doctors in North America, and this could be one of the factors associated with poorer patient survival," said the study's lead author, Dr. Mauricio Cohen, a cardiology fellow at the Duke Clinical Research Institute (DCRI).
He said that a "conservative" approach may reflect the way Latin American physicians are trained to treat heart patients. It is also possible that factors not captured in the PURSUIT trial's data, such as less sophisticated hospital facilities and staffing, may have played a role in the results of this investigation, researchers said.
Only 46 percent of Latin American patients in this study had a standard diagnostic procedure known as a cardiac catheterization, compared with 79 percent of North American patients, even though the proportion of hospitals with catheterization facilities was similar in both regions. A catheterization helps physicians pinpoint the location and extent of heart injury and is key to deciding on the best therapy for many patients, Cohen said.
The study also found that despite the lower number of invasive procedures performed in the Latin American countries, patients there were much more likely to be hospitalized in an intensive care unit than were North American patients (85 percent vs. 57 percent). This may point out an overuse of critical care beds, Cohen said.
The Latin American patients also stayed, on average, 10 days in the hospital compared with six days for North American patients. Researchers said this may be a result of the timing of catheterization in North America, where 80 percent of the procedures performed during the 30-day follow-up period of PURSUIT were performed during the first 96 hours after hospital admission, as opposed to Latin America where only 50 percent of the catheterizations were done during this period.
The differences in death rate cannot be explained by characteristics of the patients themselves, Cohen said, even though the Latin American patients who enrolled in the trial tended to be younger, shorter, weighed less and had fewer past heart procedures. "The presence and extent of coronary disease was similar in patients in the two regions," he said.
While the combined primary endpoint of the PURSUIT study - death or a heart attack at 30 days - was only slightly higher in Latin America, the difference was significant when death alone was considered - 6.8 percent of Latin American patients died compared with 3.6 percent of patients in North America.
Use of cardiac procedures differed significantly in the regions. In Latin America, 46.2 percent of patients had a diagnostic angiogram, 17.6 percent were given an angioplasty and almost 10.9 percent had heart bypass surgery. Those rates, respectively, for patients in North America were 79.4 percent, 33.6 percent, and 20.1 percent.
The use of cardiac medications differed slightly between the regions. In Latin America, patients were treated more often with ACE inhibitors and oral nitrates, and less often with heparin, lipid lowering agents and beta-blockers, which are known to improve outcomes after a heart attack.
This is the first study to compare the outcomes of heart attack patients in multiple Latin American countries - Mexico, Argentina, Venezuela, Colombia, Chile, Guatemala, Uruguay, and El Salvador - versus North America. The geographic variation of care found in PURSUIT highlights the need for further studies of practice patterns and outcomes in Latin America, researchers said. This may help identify the reasons for the differences in death rate after a heart attack.