Why You May Need This Two-Drug Combo After Stenting
Love them or hate them, these drugs help prevent blood clots inside stents.
If you have a drug-eluting stent (DES), the combination of two common antiplatelet drugs is lessening the chance that a heart attack-causing blood clot will form inside the stent. The drug regimen, known as dual-antiplatelet therapy, or DAPT, includes low-dose aspirin plus clopidogrel (Plavix™), ticagrelor (Brilinta™) or prasugrel (Effient™).
Whether you hate taking drugs or love the protection against heart attack DAPT provides, there is no doubt that DAPT plays a major role in making stenting a viable alternative to bypass surgery for the prevention or treatment of heart attack.
But just when it’s safe to stop DAPT has not been fully resolved.
“It’s complex, because medications that prevent clots can cause unwanted bleeding. Every patient who gets a DES must take DAPT for a while, but the regimen must be individualized for each patient,” says Cleveland Clinic cardiologist Stephen Ellis, MD.
The timing depends, in part, on whether or not you have had a heart attack.
DAPT After Heart Attack
Heart-attack patients are inherently prone to developing blood clots and need long-term protection.
“The data are strong that they should be on DAPT for a year or longer. Some may stay on DAPT two or three years, depending on their bleeding risk,” says Dr. Ellis.
Factors that increase the risk of bleeding include smoking, diabetes and renal failure.
Two trials of DAPT in heart-attack patients showed that prasugrel and ticagrelor were superior to clopidogrel, when used with aspirin. But they are also more expensive and cause more bleeding. “It is common to use one of these drugs for a month before switching to clopidogrel,” says Dr. Ellis.
No Heart Attack? DAPT Optional
When stenting is used to prevent a heart attack, aspirin plus clopidogrel is the gold standard. However, there is no gold standard for length of therapy: Guidelines leave it to the physician’s discretion.
“Using DAPT for one year is common, but not standard. Clinical trials performed in Europe have shown six months of DAPT to be as good as 12,” says Dr. Ellis.
“In this country, DAPT is often shortened to six months, and current trials are evaluating three months. One reason the length of DAPT can be successfully shortened is that modern DES are less prone to developing clots,” he adds.
Stopping DAPT for Surgery
Because DAPT increases the risk of bleeding, it must be stopped during surgical procedures. “Even if your physician plans for you to take DAPT for one year, after six months it may be reasonable to stop the clopidogrel or other agent, but not the aspirin, for a week before a surgical procedure, then restart it a few days after the bleeding risk from surgery has diminished,” says Dr. Ellis.
Will DAPT Disappear?
Does the gradual shortening of DAPT from years to months mean that someday it may not be necessary at all? Dr. Ellis doesn’t think so.
“I can see maybe reducing it to four to six weeks after stenting, but not discontinuing it entirely. It’s too important,” he says.