Research presented at EuroPCR 2014, held May 20-23 in Paris, France, offers both new ways to improve on current therapies and inventive approaches to treating challenging lesions and patient subsets.
Designers of the meeting focused on traditional late breaking trials as well as innovation. Several presentations featured new devices for treating mitral valve disease. A multicenter study assessed the Cardioband, a ring-like device implanted through a catheter to replace a defective mitral valve, and found the procedure to be safe and feasible with outcomes that researchers say rival surgery. An early human study of the D-shaped Tiara bioprosthesis also was positive. Furthermore, researchers presented data on the V-Wave device, which demonstrated a potential new approach to treating left heart failure, with patients seeing improvements in function and quality of life.
Global Cooperation Featured
Other presentations had creative takes on study design. The large, international CENTURY IItrial, which looked at patients slated for angioplasty with drug-eluting stents (DES), provided an example of how to streamline approval processes across regions. Patients were stratified according to whether or not they met requirements for DES use in Japan before being randomized to receive the Ultimaster stent, which releases the drug sirolimus from a biodegradable polymer, or the Xience stent, which releases the drug everolimus from a permanent polymer).
In more than 1,000 patients, Ultimaster was shown to match Xience at 9 months for the combined risk of heart-related death, heart attack, and the need for repeat treatment, both in the overall population and in the group of patients that matched Japanese regulatory requirements for DES use.
Evidence Base Grows for Recent Therapies
Transcatheter aortic valve replacement (TAVR) continued to generate headlines at EuroPCR. Initial 30-day data from theSapien 3trial demonstrated promising results with a new lower-profile valve and delivery system. The study observed low death and stroke rates and few complications associated with catheter entry.
In addition, theUK TAVI registryfound that nearly half of high-risk patients who undergo TAVR for severe aortic blockage live at least 5 years after the procedure, with long-term survival affected not by procedural and device factors but by patient characteristics.
TheIberian Registrydelivered good news on catheter-based closure of the left atrial appendage performed in Portugal and Spain. Most of the stroke protection derived from the treatment does not become apparent until 1 year after treatment, the study found. Moreover, bleeding rates are also lower than would be expected based on initial patient risk.
Various Approaches to Complicated Lesions Tested
Several late breaking trials took on bifurcations, the challenging subset of lesions that overlap into 2 different blood vessels. TheBABILONtrial compared a balloon that releases the drug paclitaxel with a stent that releases everolimus to treat these lesions. Using the balloon appears to double the amount that the vessel diameter shrinks between treatment and 9 months and to triple the need for a repeat procedure at 24 months, supporting the use of the stent in these cases.
In addition, 2trialslooked at stents designed specifically for bifurcation lesions. First, the COBRA study, randomly assigned 40 patients either to receive an Axxess stent as well as 2 Biomatrix DES—all of which release the drug biolimus A9 from a biodegradable polymer—or to undergo a technique using 2 Xience Prime stents in both the main and side branch of the lesion with overlap, called culotte stenting. At 9 months, both strategies had some positives: vessels of patients treated with the latter approach showed better healing, for example, but the vessels of those receiving the Axxess/Biomatrix combination remained more open.
Updated results from the Tryton Bifurcation Trial also were presented. The study compared a 2-stent strategy using the Tryton bare-metal stent (BMS) in the side branch and DES in the main vessel versus the accepted strategy of DES in the main vessel plus provisional side branch stenting. At 1 year, both techniques showed similar effectiveness and the Tryton stent did especially well at treating bifurcations with larger side branches.
Renal Denervation Revisited
Other analyses explored possible predictors of response to renal denervation, a procedure in which the renal arteries of patients with high blood pressure are treated with radiofrequency through a catheter to increase blood flow.
In SYMPLICITY HTN-3, positive predictors of improved office systolic blood pressure (BP) in the renal denervation arm included baseline office systolic BP, total number of procedural attempts, and drug adherence. But in those who received a sham procedure, response was predicted by baseline office systolic BP, African-American race, and alpha-1 blocker use. Vasodilator use, associated with an increase in BP, was the only negative predictor in the renal denervation group.
Moreover, analyses of the Global SYMPLICITY registry indicated that higher baseline office systolic BP and the presence of 2 or more other complications predicted overall response to renal denervation. Within a cohort of patients that mirrored the SYMPLICITY HTN-3 trial, predictors of response included higher number of procedural attempts, male sex, and higher initial office systolic BP, while greater numbers of baseline blood-pressure-lowering drugs were associated with non-response.
Challenging Disease Subsets Addressed
Two studies focused on disease in the arteries of the legs. Researchers analyzed data from a Japanese study to demonstrate that the polymer-free Zilver PTX stent, which releases the drug paclitaxel, is being used to treat progressively more challenging lesions while maintaining safety and efficacy. Another presentation provided more information about a new ultrasound system to enhance delivery of paclitaxel to these types of lesions.
In patients with severe heart attacks, theAPPOSITION IVtrial showed positive findings for the Stentys self-expanding stent, which releases sirolimus, compared with the balloon-expandable Resolute stent, which releases the drug zotarolimus. No differences were observed in vessel diameter between the stents just after the procedure. However, the self-expanding stent increased the diameter of vessels more than the balloon-expandable stent at both 4 and 9 months of follow-up.
Moreover, in theADEPTtrial, self-expanding BMS and stents that release paclitaxel fared equally well in patients who previously underwent bypass surgery yet developed new disease in a leg vein. The ability of physicians to complete the procedure was high for both groups, and no immediate differences were seen in lesion qualities after angioplasty. These results were maintained at 6 months.
Other Interventional News Presented
Also at EuroPCR 2014, astudylooking at the value of a combined noninvasive imaging technique derived from CT-scans found high accuracy in patients with suspected coronary artery disease.
Five-year findings from theNOBORI 2study showed that the Nobori stent, which releases biolimus A9, has good long-term clinical outcomes and very low rates of device-related adverse events. At 5 years, the combined risk of heart-related death, heart attack, and recurrent procedures was higher in more complex patients.
Finally, a subanalysis of theEUROMAXtrial showed that the blood thinner bivalirudin is better than heparin regardless of whether patients with severe heart attack do or do not receive glycoprotein IIb/IIIa inhibitors. Data from thePARISregistry showed that while the tendency to stop taking the antiplatelet drug clopidogrel differs between men and women, its ill effects stem more from patient characteristics than from sex differences in and of themselves.