A new study has confirmed that combining two different blood thinners doesn’t necessarily improve outcomes.
The new publication examined the minimal pros and the serious cons of combining a daily aspirin with a drug from the newer class of direct oral anticoagulants (DOACs) which include apixaban, dabigatran, edoxaban and rivaroxaban.
Patients were taking DOACs to prevent strokes from non-valvular atrial fibrillation or for the treatment of venous thromboembolic disease (deep vein thrombosis or pulmonary embolism). The included patients lacked another reason to take aspirin, such as a recent history of a heart attack or having had a heart valve replacement. One-third of those taking DOACs
“The patients on combination therapy were more likely to have bleeding events but they weren’t less likely to have a blood clot,” said lead author Jordan Schaefer, MD, an assistant professor of internal medicine and a haematologist at the University of Michigan. “Therefore, it’s important that patients ask their doctors if they should be taking aspirin when they are prescribed a direct oral anticoagulant.”
Combination therapy with an anticoagulant and an antiplatelet may be appropriate for people who have had a recent heart attack, recent coronary stent placement or bypass surgery, prior mechanical valve surgery or known peripheral artery disease, among other conditions, according to co-author Geoffrey Barnes, MD, MSc, an assistant professor of internal medicine and a vascular cardiologist at the Michigan Medicine Frankel Cardiovascular Center.
For the others, “combination therapy may not be happening intentionally; rather, the addition of aspirin might get overlooked because it’s not in any one specialist or general care provider’s territory,” Prof Barnes said.
There are many situations where an aspirin and DOAC combination has been insufficiently studied, and Prof Schaefer added that they are planning a larger, lengthier study since there were insufficient blood clots during the study to assess aspirin’s potential benefit.
Profs Schaefer and Barnes had also previously reported increased adverse outcomes for patients receiving both aspirin and warfarin, which is not a DOAC.
Source: Medical Xpress
Journal information: “Adverse Events Associated with the Addition of Aspirin to DOAC Therapy Without a Clear Indication,” JAMA Internal Medicine. DOI: 10.1001/jamainternmed.2021.1197
