Aspirin Alone After TAVR Supported by Meta-analysis

Among patients undergoing TAVR for severe symptomatic aortic stenosis who do not require anticoagulation, aspirin monotherapy seems to be a better antithrombotic approach than dual antiplatelet therapy (DAPT), a meta-analysis of recent RCTs shows.

Pooled results from four trials, including the recently reported POPular TAVI (cohort A), demonstrate that aspirin alone is associated with a lower risk of clinically significant bleeding (HR 0.49; 95% CI 0.32-0.75), with a number needed to treat of 19, according to researchers led by Mohammed Osman, MD, and Moinuddin Syed, MD (West Virginia University School of Medicine, Morgantown, WV).

Type of antiplatelet therapy was not associated with risks of all-cause mortality or stroke, they report in correspondence published online recently in the American Journal of Cardiology.

Current US guidelines recommend using DAPT with aspirin and clopidogrel for 3 to 6 months after TAVR, followed by lifelong aspirin, in patients who are not on anticoagulation; European guidelines similarly recommend DAPT early after the procedure.

It’s thought that will reduce the risk of thromboembolic events while the valve endothelializes, but “we don’t have any data to back that assumption in this kind of population,” Osman noted to TCTMD, adding that the guidance is based not on randomized studies of patients undergoing TAVR but on prior experience with coronary stenting. There are some RCTs—including POPular TAVI—that have demonstrated that using dual versus single antiplatelet therapy increases bleeding without any reduction in ischemic events.

Because those trials were not powered for ischemic endpoints, Osman, Syed, and colleagues decided to perform a meta-analysis to further explore the issue. They identified four trials with a total of 1,086 patients (mean age 80 years; 44% women) and a mean duration of follow-up of 7 months:

• POPular TAVI (cohort A): 665 patients
• ARTE: 222 patients
• SAT-TAVI: 120 patients
• Ussia et al: 79 patients

Compared with DAPT, aspirin monotherapy was associated with half the risk of clinically significant bleeding, a composite of major, life-threatening, or disabling bleeding according to VARC criteria. This endpoint was significantly lower with aspirin alone in POPular TAVI and ARTE, with point estimates in the same direction in the other two trials.

There were no differences between DAPT and aspirin alone for all-cause mortality (HR 1.00; 95% CI 0.62-1.62) or stroke (HR 1.05; 95% CI 0.58-1.90), similar to the results of each of the included trials.

Asked why there wouldn’t be a reduction in thromboembolic risk with more-potent antiplatelet therapy, Osman pointed out that patients undergoing TAVR are inherently different from those undergoing coronary stenting. They tend to be older and to have more comorbidities, placing them at higher risk for bleeding.

Though the meta-analysis was limited in that it was performed with study-level—and not patient-level—data, Osman said there is probably enough evidence now to change recommendations around post-TAVR antithrombotic therapy, particularly after the release of the POPular TAVI results. “I think in the next iteration of the guideline, they will definitely consider the findings from that trial,” he said.