Efficacy of Short Duration Dual Therapy for Transient Ischemic Attack and Minor Stroke

Mark J. Alberts, MD, FAHA, FAAN, Co-Physician-in-Chief, Ayer Neuroscience Institute; Chief of Neurology, Hartford Hospital; Professor of Neurology, University of Connecticut, reviewed recent research on the treatment of transient ischemic attack (TIA) and minor stroke during a virtual presentation for Neurology Week.

There are close to 800,000 new or recurrent strokes yearly in the US, with 85% of strokes being ischemic and at least 30% being minor. There are at least 500,000 transient ischemic attacks yearly in the US, which can put patients at risk of stroke and other cardiovascular events.

“Interventions to reduce the risk of recurrent events will have a significant impact on public health and patient outcomes,” Dr Alberts said.

A large TIA/minor stroke registry observed patients from 21 counties with transient ischemic attack or minor stroke within 7 days of enrollment over a course of 5 years.  Results showed that cardiovascular events continued throughout the 5 years, with half occurring in the first year and half occurring in year 2 to 5. Improved risk factor control may reduce the number of events in later years.

An analysis of 12 trials and a total of 15,778 patients mapped the impact of aspirin versus the local control on early recurrent stroke following transient ischemic attack and ischemic stroke.

In the first six weeks, patients in the aspirin receiving group had less bad outcomes.

“The greatest impact is in the first 5 to 10 days of therapy, or first two weeks, where the hazard ratio really falls significantly with aspirin compared to control,” Alberts said.

Following the early days of therapy, the difference between aspirin and local control becomes insignificant. Results of the analysis show that using aspirin compared to standard therapy in the first 10 days can be effective at limiting outcomes such as non-disabling ischemic stroke and disabling or fatal ischemic stroke. 

Dr Alberts spoke to the prospective randomized MATCH study, comparing aspirin alone to aspirin paired with clopidogrel among patients with recent stroke or transient ischemic attack receiving 18 months of therapy.

The primary endpoints were composite of ischemic stroke, myocardial infarction, vascular death, and rehospitalization. Dual therapy showed a 1% absolute risk reduction on the primary endpoint, and no benefit was found for long-term dual therapy.

A similar dual antiplatelet trial, POINT, compared aspirin alone to aspirin paired with clopidogrel on patients receiving therapy for 3 months. Results showed that dual therapy reduced subsequent ischemic events but caused risk of major bleeding.

Among other trials, Dr Alberts mentioned the COMPASS trial, which randomized patients with stable coronary artery disease and peripheral artery disease into aspirin vs rivaroxaban or rivaroxaban paired with aspirin. Results showed that the combination therapy was safer than rivaroxaban alone for composite of stroke, myocardial infarction, or vascular death.

Based on his review of research, Dr Alberts concluded that there is an enhanced efficacy with dual AP therapy, though more bleeding events occur.

He suggested that shorter duration dual therapy appears to be the safer, best option.

Even shorter durations of dual therapy could offer a safe alternative, Dr Alberts said.

“Shorter duration appears to be a very good option, because the shorter you're given the dual therapy, somewhat lower is the risk for bleeding events,” he concluded. “Could even shorter therapy, less than 30 days, like 7 to 10 days offer a safer alternative? We don't know, but it's certainly a testable hypothesis.”

—Erin McGuinness

Alberts, J Updates on Antithrombotic Stroke Prevention Strategies. Presented at Neurology Week 2021; July 14-18. Virtual.