People who are taking low-dose aspirin to help their hearts benefit substantially if they continue to take it in the days prior to bypass surgery, a Mayo Clinic study indicates.
The researchers looked at more than 1,600 people who had bypass operations at the Mayo Clinic, and found that the in-hospital death rate for those who took aspirin in the five days before surgery was 1.7%, compared with 4.4% for those who did not take aspirin.
Some surgeons have patients stop taking aspirin before bypass surgery because of the fear of excessive bleeding. But the study found no increased incidence of re-operation because of internal bleeding, according to the lead author of the report, Dr. R. Scott Wright, a Mayo Clinic cardiologist.
The incidence of death and stroke was significantly lower in patients taking aspirin, Wright reports.' And in those who took aspirin, there was a reduced need for postoperative blood products."
The aspirin did what it was supposed to do prevent heart attacks and other cardiac events by making blood flow more freely, he explains.
"We know that many of the deaths that occur after the operation are due to ischemic heart disease," in which a coronary blood vessel is blocked, Wright says.
Although the study supports the findings of smaller studies done in other countries, the case for giving aspirin before bypass surgery is still not definitively proved, he says.
"This is level two evidence-an observational study," Wright says. 'A randomized trial is needed for definitive evidence. The data from this study would justify carrying out a randomized trial in patients getting bypass surgery."
The Case For Aspirin
"These new data from the Mayo Clinic certainly help support the case for using aspirin before surgery," says Dr. Eric Topol, chairman of the department of cardiovascular medicine at The Cleveland Clinic.
The case for using aspirin immediately after bypass surgery has been proven by a number of studies showing major benefits, Topol says, but there has been a debate about its use before surgery because the data has been mixed about whether aspirin creates a bleeding hazard.
The Mayo study shows that "the bleeding hazard doesn't appear to be in any way prohibitive," Topol says.
In practice, surgeons at The Cleveland Clinic generally continue aspirin therapy if the bypass patient has been taking it, he says. However, it is not yet standard procedure to start a patient on aspirin in the days before surgery, unless there are unusual circumstances, such as a high risk of a heart attack, Topol says.
"Patients who have heart disease and are not taking aspirin should ask themselves-and their doctors-''Why not?"' he adds