AHA.15: Using intravascular ultrasound in stent implantation improves cardiac outcomes

After one year, patients with long coronary lesions who were implanted with an intravascular ultrasound-guided everolimus-eluting stent had a significantly lower rate of major adverse cardiac events compared with those implanted with an angiography-guided stent.

Lead researcher Sung-Jin Hong, MD, of Sanggye Paik Hospital and Inje University in Seoul, Korea, published their results online in JAMA on Nov. 10. The findings were simultaneously presented at the American Heart Association Scientific Sessions.

The researchers mentioned that previous studies found that the prevalence of in-stent restenosis and stent thrombosis after PCI in patients with long coronary lesions was higher than in patients with short-length coronary lesions. However, they also noted no randomized trials had evaluated the clinical usefulness of intravascular ultrasound for second generation drug-eluting stents.

This trial, known as IVUS-XPL (Impact of Intravascular Ultrasound Guidance on Outcomes of Xience Prime Stents in Long Lesion), enrolled 1,400 patients with typical chest pain or evidence of myocardial ischemia between October 2010 and July 2014 at 20 centers in Korea.

The mean age was 64, and 69 percent of patients were men.

Patients were implanted with an everolimus-eluting stent (Xience prime, Abbott Vascular) for long coronary lesions and randomized to receive intravascular ultrasound-guided or angiographic-guided stent implantation immediately after their pre-PCI angiogram. The researchers defined long coronary lesions as at least 28 mm in length.

One year after the procedures, major adverse cardiac events occurred in 2.9 percent of patients undergoing intravascular ultrasound-guided stent implantation and 5.8 percent of patients in the angiographic-guided group.

The researchers defined major adverse cardiac events as cardiac death, target lesion-related MI and ischemia-driven target lesion revascularization (TLR).

Cardiac death occurred in three patients in the intravascular ultrasound-guided group and five patients in the angiographic-guided group, while ischemia-driven TLR occurred in 17 and 33 patients, respectively. One patient in the angiographic-guided group also had target lesion-related MI.

There were no significant differences in cardiac death and target lesion-related MI between the groups, although significantly more patients in the angiographic-guided group had ischemia-driven TLR.

Further, the researchers noted that the use of intravascular ultrasound was associated with a 2.9 percent absolute reduction and 48 percent relative reduction in the risk of major adverse cardiac events.

A post hoc analysis of patients in the intravascular ultrasound-guided group found 4.6 percent of patients who did not meet the intravascular ultrasound criteria and 1.5 percent of patients who met the intravascular ultrasound criteria had a major adverse cardiac event.

The researchers noted a few limitations, including that there are no established criteria for intravascular ultrasound criteria after PCI. They also mentioned angiography-guided procedures may not have been exclusive of the intravascular ultrasound technique because physicians in the study were proficient in both approaches.

In addition, they wrote that the overall event rate for major adverse cardiac events was lower than they expected. Before the trial, they anticipated an event rate of 7 percent in the angiography-guided group.