NEW YORK (Reuters Health) – Patients who have a transient ischemic attack (TIA) or stroke while they’re on aspirin may have better vascular health and avoid future strokes if they add or switch to another antiplatelet agent within days, a new meta-analysis suggests.
“If what the data seem to show are true, they are very important and tell us that, if patients who come to the hospital with a stroke are already taking aspirin, it might be better for them to leave the hospital on a different antiplatelet drug or on a combination of antiplatelet drugs,” Dr. David E. Thaler of Tufts University School of Medicine in Boston, Massachusetts, told Reuters Health.
“Thinning the blood works for preventing strokes; thinning the blood more might work better. Dual antiplatelet therapy clearly has a stronger antithrombotic effect. And if we think an antithrombotic effect is beneficial for stroke prevention, that would make sense,” he said in a phone interview.
“The cost of increased anti-thrombotic effect is increased bleeding, but according to this meta-analysis, on balance there wasn’t enough increased bleeding to outweigh what the authors perceived to be a benefit,” added Dr. Thaler, who was not involved in the study.
As reported online July 12 in Stroke, researchers led by Dr. Meng Lee of Chang Gung Memorial Hospital in Chiayi, Taiwan, searched major medical databases to identify randomized trials and cohort studies involving patients who were on aspirin at the time they had a TIA or ischemic stroke.
The authors selected five studies involving 8,723 patients. Overall, four studies used clopidogrel and one study used ticagrelor. In pooled results, compared with aspirin monotherapy, adding or switching to another antiplatelet agent was associated with decreased risk of major adverse cardiovascular events (hazard ratio, 0.68; 95% confidence interval, 0.54 to 0.85) and recurrent strokes (hazard ratio, 0.70; 95% confidence interval, 0.54 to 0.92).
Each strategy of adding and switching to another antiplatelet drug benefitted the patient more than continuing aspirin monotherapy. Studies that began treatment within days of the TIA or stroke showed more consistent evidence of benefit.
Dr. Fadi B. Nahab of Emory University in Atlanta, Georgia, told Reuters Health in an email, “This is important, as medical providers may simply take a TIA or ischemic stroke patient on aspirin 81mg daily and increase the dose to 325mg daily, thinking that this dose change will reduce the patient’s risk of recurrent stroke. These results question that approach.”
“The findings are not surprising because an ischemic stroke or TIA is most often caused by a thrombotic or embolic event. If aspirin use did not prevent the original TIA or ischemic stroke, it would be intuitive to think that utilizing the same aspirin regimen would not be effective to prevent a recurrent cardiovascular event,” Dr. Nahab, who also was not involved in the study, explained.
Dr. Nahab cautioned that one potential weakness of the study is that the level of adherence to each antiplatelet regimen used in the various trials is not stated, and he noted that other cardiovascular studies have shown that the most common cause of ‘aspirin failure’ is actually non-adherence to a daily aspirin regimen.
Also, the study does not address whether switching to a different antiplatelet drug is more or less effective than adding an antiplatelet to aspirin, he said.
“This paper is not definitive but is provocative,” Dr. Thaler said. “This is not a randomized trial designed specifically to look at this question. It is, though, a very clever and well-done meta-analysis of existing data. If the data are true, these results may change clinical practice.”
This meta-analysis is important because a clinical trial that would best ask this question would be difficult to conduct due to the small number of patients who have a stroke while they are already taking aspirin, he explained.
“Stroke is not a disease, it’s the endpoint of many other diseases,” Dr. Thaler noted. “I want to caution people not to think about and evaluate stroke patients too simplistically. Stroke has many causes and we need to identify the cause and target our therapies as best as possible.”
“Every patient deserves individualized treatment,” he advised. “Though these data are helpful, they shouldn’t be seen as a way to avoid investigating patients and their individual stroke mechanisms.”
The authors were not able to respond to requests for comment.
Grants from the Ministry of Science and Technology and Chang Gung Memorial Hospital, both of Taiwan, funded the study.
SOURCE: http://bit.ly/2vCdRS8
Stroke 2017.
Tidak ada komentar:
Posting Komentar