Biolimus-eluting vs. bare-metal stents: what are the long-term benefits after a heart attack?

This study investigated the long-term effectiveness of biolimus-eluting stents (BES) versus bare-metal stents (BMS) to treat heart attacks.

They found that BES was linked to a reduced risk of major cardiac events (MACE) after 5 years.

Myocardial infarction (MI) or heart attack is a serious cardiac event. It is caused by reduced blood flow to the heart. A stent can be used to restore blood flow after a heart attack. A stent is surgically placed in the coronary artery. This is a minimally invasive procedure. While placing the stent, the blockage can be removed. Stents can improve blood flow to the heart long-term. Some stents are made with metal only. These are called bare-metal stents (BMS). 

Newer stents have been developed with additional functions. Some stents are coated with substances called polymers. These polymers are natural substances that can carry drugs or chemicals. Biolimus-eluting stent (BES) is an example of this. BES is coated with a compound called umirolimus (UML). UML has anti-inflammatory properties. Inflammation can increase the risk of heart attack. It is unclear if BES is more effective than BMS long-term. 

This study included 1100 patients that had either BMS (550) or BES (550) after a heart attack. The authors performed follow-up 5 years after the procedure. The main outcome of interest was the rate of major adverse cardiac events (MACE). This included heart attacks, stroke or death. Ultrasound studies were performed in some patients. This was to assess any blockages in the artery. The rates of target lesion revascularization (TLR) were also compared. TLR is a secondary procedure to restore blood flow if a stent fails. 

The risk of MACE was 44% lower after BES at the 5-year follow-up. The risk of another MI was 56% lower after BES. The risk of TLR due to reduced blood flow was 59% lower after BES. BES was well-tolerated and the almost complete healing of the artery was observed in BES patients.  

The authors concluded that BES was linked to a reduced risk of MACE after 5 years.

Patients in this trial were not randomly assigned to the groups. Newer, thinner stents are also available. It remains to be seen if BES will be the best option for patients after a heart attack.