In patients with acute coronary syndrome who have undergone PCI, abbreviated dual antiplatelet therapy (DAPT) appears to improve the balance between bleeding and ischaemic risk, although uncertainty remains over the optimal timing of aspirin discontinuation, researchers report.
Interventional cardiologists have faced a trade-off in trying to balance bleeding and ischaemic risks, including stent thrombosis, when managing patients post-PCI. Recent research suggests that both follow different trajectories over time.
Yet the sweet spot for stopping aspirin remains more nuanced.
The review included more than 34,000 patients randomised to short DAPT followed by P2Y12 or standard 12-month DAPT treatment.
The findings indicate that early discontinuation of aspirin and continuing a P2Y12 inhibitor (generally ticagrelor or clopidogrel) reduced net adverse clinical events (NACE), largely by cutting major bleeding, without resulting in excess major adverse cardiovascular events (MACE).
The researchers used pairwise and network meta-analyses to directly and indirectly compare short DAPT (aspirin-free, less than one month, one month and three months), each followed by P2Y12 inhibitor monotherapy with 12-month DAPT.
The study’s primary endpoint was study-defined NACE, a composite of bleeding and ischaemic outcomes, while secondary outcomes included major bleeding and study-defined MACE.
Short DAPT followed by P2Y12 inhibitor monotherapy reduced NACE compared with standard DAPT (risk ratio (RR) 0.77), driven primarily by major bleeding (RR 0.46). In network meta-analyses, all individual short DAPT strategies followed by P2Y12 monotherapy, except aspirin-free, reduced NACE, with no significant difference between them.
Three-month DAPT, meanwhile, consistently ranked favourable for MACE and individual ischaemic endpoints. However, there were no statistically significant differences between the individual short-DAPT strategies.
At the same time, discontinuation of aspirin within one month ranked highest for NACE.
“Although a brief period of DAPT appears warranted after ACS, the optimal timing of aspirin discontinuation remains uncertain,” the investigators wrote.
“While earlier aspirin discontinuation may be associated with greater clinical benefit owing to reduced bleeding, three-month DAPT may be associated with more favourable ischaemic outcomes, underscoring the importance of individualising DAPT duration according to bleeding and ischaemic risk.”
Within the paired comparisons, short DAPT reduced NACE at 12 months compared with standard DAPT (RR 0.77). In the network meta-analyses, researchers found significant reductions in NACE with DAPT of less than one month, one month and three months, but not with the aspirin-free strategy.
“Of note, early aspirin discontinuation in abbreviated DAPT strategies did not increase the risk of MACE or other ischaemic outcomes, in line with previous meta-analyses,” they wrote.
“However, in multiple sensitivity analyses, the aspirin-free strategy was associated with a higher risk of MACE when compared with regimens including at least 1 month of DAPT. Notably, the aspirin-free strategy was tested in only one RCT.
In general, the researchers noted, DAPT strategies followed by P2Y12 inhibitor monotherapy reduced NACE compared with standard DAPT, mainly driven by reduced bleeding. The benefit related to NACE was seen when aspirin was discontinued at <1–3 months, with the <1 month strategy ranking highest for net clinical benefit.
They added, however, that “given the absence of significant differences between individual short DAPT strategies, this ranking should be interpreted cautiously and no specific timing of aspirin discontinuation after short DAPT can be considered clearly superior.”
Full study findings are published in Heart [link here].