People
taking low-dose aspirin to help their hearts benefit substantially if they continue to take it in the days before they have
bypass surgery, a new Mayo Clinic study indicates. The researchers looked at
more than 1,600 people who had bypass operations at the Mayo Clinic between 2000 and 2002, and found that the in-hospital
death rate for those who took aspirin in the five days before surgery was 1.7 percent, compared to 4.4 percent for those who
didn't.
Some
surgeons have patients stop taking aspirin before the operation for fear of excessive bleeding. But the study found no increased
incidence of re-operation because of internal bleeding, said Dr. R. Scott Wright, the Mayo cardiologist who was the lead author
of the report in the Aug. 30 issue of Circulation. [Caution, FOR ALL NSAID: those who take more would have a bleeding problem. In small doses, too low for pain, the platelet reduction is minimal and thus little
effect upon bleeding—jk.]
"We
were pleased to find that the perioperative death rate was significantly lower, as well as cerebrovascular events [strokes],"
Wright said. "And in those who took aspirin, there was a reduced need for postoperative blood products. Aspirin prevents heart attacks and other cardiac events by making blood flow more freely,” he added. "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 said. But
although the study supports the findings of smaller studies done in other countries, the case for giving aspirin before bypass
surgery is not definitively proved, he said. "This is level 2 evidence, an observational
study," Wright said. "A randomized trial is needed for definitive evidence. The data from this study would justify carrying
out a randomized trial in patients getting bypass study."
"These
new data from the Mayo Clinic certainly help support the case for using aspirin before surgery," said 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 said,
but there has been a debate about its use before surgery because "the data has been a bit mixed about bleeding hazard and
graft success." The Mayo study shows that "the bleeding hazard doesn't appear
to be in any way prohibitive," Topol said. In practice, surgeons at the Cleveland
Clinic generally continue use of aspirin if the bypass patient already has been taking it, he said. But it is not yet standard
procedure to start a patient on aspirin in the days before surgery, unless there are unusual features, such as a high risk
of a heart attack, Topol said.
The
new report is another indicator of the value of aspirin in the treatment of heart disease, Wright said.
SOURCES:
R. Scott Wright, M.D., cardiologist, Mayo Clinic, Rochester, Minn; Eric Topol, M.D., chief, cardiovascular medicine, Cleveland
Clinic; Aug. 30, 2005, Circulation
This
study is not up as of 10/9/5 on the nih.gov website, but is in preparation for being published. However the news release on their website at http://www.mayoclinic.org/news2005-rst/3010.html?SUBMIT=Search, but the Mayo Clinic release was.
ROCHESTER, Minn. -- A new Mayo Clinic study provides further evidence of aspirin's
benefits for patients with heart disease and suggests they should continue taking it even in the days leading up to surgery.
"Aspirin reduces clotting of the blood, so it can help prevent a heart
attack or stroke by making it less likely a clot will form and block an already narrowed artery," explains R. Scott Wright,
M.D., the Mayo Clinic cardiologist who led the study. "However, many surgeons who are concerned about excessive bleeding due
to inadequate clotting have advised their patients to stop taking aspirin in the days before their operation. We designed
this study to provide guidance on whether continuing aspirin therapy in the days before surgery is beneficial or risky." [there is a very significant risk for those
taking more than the low does. Arthritic patients take on an average of 2 grams
(2,000 mg) of aspirin a day or of an NASID equivalent such as ibuprofen. With
such a does there is an acute bleed problem.jk]
The researchers collected data from 1,636 patients who had first-time coronary
artery bypass surgery at Mayo Clinic in 2000, 2001 and 2002. Patients were divided into two groups: those who had taken aspirin
within the five days before surgery (1,316 patients), and those who had not (320). Characteristics of the two groups were
similar, except patients in the aspirin group were more likely to have had a previous heart attack, while those not taking
aspirin were more likely to be on dialysis. All members of both groups received aspirin therapy following surgery, starting
six hours after their operation.
Results
The in-hospital mortality for the aspirin group (1.7 percent) was significantly
less than that for those not receiving aspirin (4.4 percent), and there was no increased risk of reoperation for excessive
internal bleeding.
The study results suggest a reduction in strokes and related events, but the
trend was not strong enough to be statistically significant.
"This is a very strong association of survival with taking aspirin in the days
leading up to surgery," says Dr. Wright. "The study further confirms aspirin's benefits for patients with known cardiovascular
disease. It also shows there is no increased risk of bleeding, which eliminates the main reason why physicians and surgeons
would ask patients to discontinue aspirin therapy. Patients with heart disease who are not taking aspirin should ask themselves
-- and their doctors -- 'Why not?'"
The findings are published this week in Circulation: Journal of the American
Heart Association. Other co-authors include Kevin Bybee, M.D., Brian Powell, M.D., Uma Valeti, M.D., A. Gabriela Rosales,
M.S., Stephen Kopecky, M.D., and Charles Mullany, M.B. M.S.
The study was funded by Mayo Clinic's Division of Cardiovascular Diseases.
Dr. Wright has previously received research grant support from Bayer Pharmaceuticals.
Monday, August 29, 2005
Mayo Clinic Study: Don't Stop Taking Aspirin Before
Heart Surgery