The EuroPCR 2011 meeting, held May 17-20, in Paris, France, offered clinical trial results and new developments with the potential to impact interventional cardiology.
A prime example to emerge from this year's conference was a new imaging technique referred to as noninvasive fractional flow reserve (FFR), which uses computer calculations and standard imaging methods to create threedimensional images of the heart. The test can help determine whether a given blockage actually affects blood flow to the heart muscle without the use of harmful dyes or an invasive procedure.
Noninvasive FFR was this year's recipient of the EuroPCR Innovation Award based on findings from the DISCOVERFLOW trial. For the study, patients underwent both noninvasive FFR and computed tomographic (CT) angiography. The newer technique turned out to be even better than its competitor at diagnosing heart disease, suggesting patients may be able to undergo fewer invasive tests.
Maximizing Primary Angioplasty
A number of trials focused on how to improve existing treatments. In a substudy of the HEBE III trial, patients with severe heart attacks received a stent designed to capture stem cells that circulate in the body. Some patients also received a dose of the hormone erythropoietin at the time of stenting. Compared to those who did not receive the hormone, these patients were less likely to have renarrowed vessels at nine months and less likely to need repeat angioplasty at one year. However, researchers cautioned that it is unclear whether the stent or the drug made the difference.
Two other additive therapies showed promise for preserving heart muscle. In the ROMA trial of patients undergoing elective angioplasty, those who received the cholesterol-lowering drug rosuvastatin 24 hours before the procedure had less muscle tissue death and fewer major heart complications than patients who received standard therapy. Similarly, in the POSTCON II trial, patients who received exenatide, a drug typically given to treat type 2 diabetes, had more heart muscle salvaged after experiencing severe heart attacks than did those who received placebo.
On the other hand, another approach called postconditioning— cycles of balloon inflation and deflation in the first few minutes after angioplasty to restore blood flow—failed to be protective and even appeared to be harmful in the POST-AMI trial.
Demonstrating that technique matters, a study of Swedish patients from a large national registry found that those who underwent angioplasty via an artery in their wrist, rather than an artery in their groin, had a lower likelihood of death at 30 days and 1 year, fewer bleeding complications, and shorter hospital stays.
Good News for Drug-Eluting Balloons, New Stents
Drug-coated balloons also made an appearance at EuroPCR. In five-year combined results from the Paccocath ISR I and II randomized trials, patients whose previously opened arteries had begun to reclose were less likely to need repeat procedures after receiving angioplasty with a drug-coated balloon compared with a plain balloon. Death, heart attack, stroke, and stent-related blood clots were similar for the two technologies.
Analysis of patients in ISAR-TEST 3, ISAR-TEST 4, and LEADERS showed that at 3 years, a drugeluting stent with a polymer coating that is absorbed into the body reduced repeat procedures and halved the rate of blood clots compared with a standard drugeluting stent featuring a permanent polymer, although there was no difference in the combined risk of heart-related death or heart attack.
Taking on Challenging Patients, Complications
Antiplatelet therapy is a cornerstone in the management of patients with acute coronary syndromes or those undergoing angioplasty. In the RECLOSE 2-ACS trial, researchers targeted patients who did not respond adequately to the standard bloodthinning drug clopidogrel and attempted to give higher doses or shift them to a different drug known as ticlopidine. Regardless of these efforts, nonresponders still experienced higher long-term heart-related death and more stentrelated blood clots than those who responded adequately to the initial clopidogrel dose.
For the DIRECT trial, researchers studied the risk of a complication known as contrast-induced nephropathy, a kind of kidney damage that occurs in some patients in response to the dye used during heart X-rays, or angiography. The study offered both good and bad news: the complication was rare even in high-risk patients who already had impaired kidney function but neither of two dye agents hoped to reduce damage (iopromide or iodixanol), appeared particularly effective.
The CTO-1 trial, meanwhile, reported a new way to cross chronic blockages in patients undergoing angioplasty. Before treatment, researchers used bacteria-derived enzymes to soften up the blockages that had previously resisted treatment. The next day, these lesions were successfully crossed with a small wire and stented. Few complications occurred, and all stented arteries remained open at 3 months.
After angiography, vascular closure devices are often used to stop artery bleeding as quickly as possible. In the CLOSE-UP trial, treatment with one of these devices appeared more effective than manual pressure at the treatment site at reducing bruising while patients were in the hospital. Other outcomes were the same for both groups.
