Lp(a) levels play an important role in predicting subsequent ischemic events in patients with established coronary artery disease (CAD), especially those who underwent PCI. However, there are still no approved pharmacologic therapies that specifically target high Lp(a) levels.
DAPT consisting of aspirin and a P2Y12 receptor inhibitor represents the cornerstone of pharmacological treatment aimed at preventing thrombotic complications after PCI. Considering that Lp(a) has a prothrombotic effect through its inactive, plasminogen-like protease domain on apo(a), the investigators speculate that prolonged DAPT may have a beneficial effect on reducing future ischemic events in patients with elevated Lp(a) levels after PCI. Some observational studies revealed that DAPT > 1 year was significantly associated with lower risk of cardiovascular events compared with DAPT ≤ 1 year in patients with elevated Lp(a) levels who were event-free at 1 year after PCI with DES. However, the relative efficacy and safety of prolonged DAPT versus standard DAPT in this high-risk population has never been assessed in randomized controlled trials (RCTs).
The DAPT-Lp(a) trial is a multicenter, parallel-group, randomized controlled trial with blinded end-point evaluation. Consecutive patients with Lp(a) levels>30mg/dL who meet the inclusion criteria and none of the exclusion criteria will be randomized in a 1:1 fashion to 24-month DAPT group or 12-month DAPT group. The investigators hypothesise that, in patients with Lp(a) levels >30mg/dL who were event-free at 1 year after PCI with DES, 24-month DAPT is superior to 12-month DAPT with respect to major adverse cardiovascular and cerebrovascular events (primary end point), while it is non-inferior to 12-month DAPT with respect to net adverse clinical events (key secondary end point).
The investigators estimated that 3,300 patients would be needed to provide the necessary number of confirmed endpoints to test the study hypothesis. Patients will be followed up at 3, 6, 9, 12 months after randomization. All analyses will be performed according to the intention-to-treat (ITT) principle.