Does long-term dual antiplatelet therapy (DAPT) increase the risk of bleeding after a PCI?

This study looked at the outcomes of patients treated with single or double long-term antiplatelet therapy (APT) after a percutaneous coronary intervention (PCI) using second-generation drug-eluting stents (DES). It found that single APT (SAPT) resulted in a lower risk of bleeding compared to dual APT (DAPT). 

Coronary artery disease (CAD) refers to blockages in the blood vessels in the heart. CAD can deprive the heart of oxygen and result in a heart attack or death. CAD is treated by unblocking the blocked blood vessel. One way of doing this is by inserting a stent into the blocked vessel which acts as a scaffold to hold the vessel open. This procedure is called percutaneous coronary intervention (PCI). 

PCI often uses a type of stent called a drug-eluting stent (DES). DESs release a drug that slows the healing of the vessel to stop tissue from growing over the stent and blocking it again. However, slow healing can result in blood clot formation and this can also block the vessel. Treatment is therefore needed to stop the formation of clots. 

APT is used to stop clot formation. Usually, two APT drugs are used at the same time. This is called dual APT (DAPT).  When only one APT drug is used it is called single APT (SAPT). However, APT drugs increase the risk of bleeding. It is not clear which is the best APT protocol after PCI to prevent the risk of further blockages as well as prevent bleeding.

This study compared the results of 5 previous studies looking at APT after PCI. Overall, 32 145 patients were included. Patients were divided into two groups. Both groups received DAPT for 3 months. Group 1 further received DAPT for at least 12 months. Group 2 continued with SAPT with a P2Y12 inhibitor such as clopidogrel (Plavix), ticagrelor (Brilinta), or prasugrel (Effient) after the 3 months of DAPT.  Patients were monitored for signs of stent failure such as stent blockage, heart attack, or death. They were also monitored for episodes of bleeding.

Group 1 had a 37% higher risk of major bleeding compared to group 2. There were no differences in the rates of stent blockage, heart attack, stroke, or death between groups. 

This study showed that using short-term DAPT followed by long-term SAPT with a P2Y12 inhibitor was just as effective as long-term DAPT treatment while reducing the risk of bleeding following PCI.  

The studies analyzed had different protocols. The timing of aspirin interruption in short-term DAPT was different among studies. This might have influenced the results.