Shelley Wood

March 29, 2011

March 29, 2011 (New Orleans, Louisiana) — Think small: depending on how a host of big trials turn out, "less is more" may end up being the major lesson from this year's American College of Cardiology (ACC) 2011 Scientific Sessions/i2 Summit, which is dominated by tiny devices and less invasive approaches. The line-up of trials is also downsized this year--17 studies spread over four sessions, compared with the groaning table at last year's meeting, featuring 25 trials spread over five separate sessions.

Dominating the terrain as it did at last year's TCT meeting is the PARTNER trial, allotted the whole of the first late-breaking clinical-trials session, starting Sunday at 9 am. The first of two trial presentations is the long-awaited cohort A results, comparing 12-month outcomes among nearly 700 patients randomized to either aortic-valve surgery or to transcatheter aortic-valve implantation (TAVI). Unlike PARTNER cohort B, which compared outcomes in patients who were ineligible for surgery treated with either TAVI or best medical therapy (with or without balloon valvuloplasty), cohort A is enrolling patients who are suitable for surgery. The primary end point is one-year survival, with the study designed to demonstrate that TAVI is noninferior to surgery. Dr Craig Smith (Columbia University, New York, NY) will present the cohort A findings Sunday at 9:15.

Of note, in what may be a hint at the kind of results cohort A will deliver, Smith's presentation actually follows a taped TAVI case, presented by Dr E Murat Tuzcu (Cleveland Clinic, OH). Contacted by heartwire Monday, Tuzcu confirmed that the taped case involves a "cohort A"-type subject, a high-risk patient eligible for surgery, which raises the question of whether the ACC/i2 Summit program chairs would spotlight a taped case of a patient in whom the procedure being studied was ultimately shown to be inferior to or less safe than surgery.

In the second part of this TAVI-centric late-breaking session is a "lifetime cost-effectiveness" analysis from cohort B, the final piece of the puzzle following the quality-of-life data presented at last year's AHA meeting.

Speaking with members of the media during a telebriefing yesterday, ACC president Dr Ralph Brindis, ACC 2011 cochair Dr Edward McNulty, and i2 Summit chair Dr David Moliterno made it clear that PARTNER is, far and away, the star attraction at this year's meeting, with McNulty stressing the "tremendous interest" across cardiology specializations in the question of whether the dramatic mortality reductions seen in cohort B patients undergoing TAVI could be extended to patients who already have surgery as a treatment option.

Other Late-Breakers

On Monday, the first of two late-breaking clinical-trials sessions continues to probe the role of surgery in modern-day care, including further follow-up from trials that debuted at previous major meetings. These include the "hypothesis-one" results from STICH, comparing CABG and best medical therapy in patients with congestive heart failure and severe LV dysfunction, and two-year results from the EVEREST II study using the percutaneous MitraClip vs surgery for mitral-valve disease. One-year results from EVEREST II, presented at last year's ACC meeting, were promising, McNulty observed to the press, but added: "There were some concerns regarding durability, so there is a lot of interest in whether these results stand the test of time."

Also on the CABG front are five-year results comparing radial artery versus saphenous vein patency from the RAPS study and the PRECOMBAT findings, comparing surgery and drug-eluting stents (DES) for left-main disease.

Stents and PCI then dominate the second late-breaking clinical-trials session on Monday, starting at 10:45, with results from two DES trials (RESOLUTE and PLATINUM) and a study of DES in saphenous vein grafts, ISAR-CABG. One of the most anticipated presentations of this year's ACC also debuts in this session, the RIVAL trial, comparing radial vs femoral access for coronary angiography and interventions in ACS patients. Brindis, in fact, singled out RIVAL as having the biggest potential for an impact on cardiology practice, after PARTNER, depending on the findings. Rounding out this session is a contrast-nephropathy prevention trial, REMEDIAL II, involving randomization to optimal management (sodium bicarbonate and N-acetylcysteine) or the "RenalGuard" system--a "real-time measurement and matched fluid-replacement device," based on the premise that high urine output can protect patients with renal dysfunction undergoing PCI.

The fourth and final late-breaking trials session, starting Tuesday at 8 am, offers something, finally, for the folks with little or no interest in medical devices. Leading off the session is the MAGELLAN trial of rivaroxaban vs enoxaparin for prevention of venous thromboembolism (VTE). Next up are two Japanese hypertension trials: the first, OSCAR, comparing a high-dose angiotensin II receptor blocker (ARB), olmesartan 40 mg, with a combination of olmesartan 20 mg plus a calcium-channel blocker in high-risk, elderly hypertensive patients. The second, NAGOYA HEART, is testing valsartan and amlodipine in hypertensive patients with glucose intolerance.

Rounding out the session is the phase 2b PROTECTION-AMI study, testing a novel isozyme-selective delta protein kinase C inhibitor designed to reduce ischemia and reperfusion injury following AMI, and EXCELLENT, a randomized comparison of six-month vs 12-month dual antiplatelet therapy following DES implantation.

Beyond the Big-Tent Trials

Outside the late-breakers, the 2011 ACC/i2 Summit program also offers a single session entitled "Featured Clinical Research." One of these sessions presents results from the trial of the Rheos device, which raised eyebrows last year when preliminary data from this study were yanked at the last minute from the program at the American Society of Hypertension (ASH) meeting, even though the results had already been discussed with the press. As reported by heartwire later in the summer, a data safety and monitoring board told the company that one of the pivotal trial's end points was unlikely to be met, so the future of the device was in question. The title of the presentation at ACC, however, suggests that baroreflex activation therapy "sustainably lowers BP."

Also featured in this session is a trial on LV lead placement in the TARGET study, a presentation on reduced anticoagulation for a mechanical heart valve, and a prospective, randomized, multicenter trial on patient follow-up, stratified by N-terminal pro-brain-type natriuretic peptide (NT-proBNP), in outpatient HF clinics.

A "hot-button" topic highlighted during Monday's media briefing was PCI appropriateness, an issue that has been in the limelight following investigations of cardiologists in Maryland, Philadelphia, and elsewhere. On Tuesday at 8 am, Dr Paul Chan (St Luke's Mid-America Heart Institute, Kansas City, MO) and colleagues are presenting a nationwide review of 500 000 PCIs included in the NCDR CathPCI Registry, documenting what proportion of procedures done in the US are appropriate or inappropriate, based on "appropriate-use" consensus documents.

While the number of "late-breaking" and "featured" trials is slightly less this year, McNulty told the press that the overall tally of original oral abstracts in the program is actually up by 10% over last year. Moliterno noted that there will be a number of live and taped cases throughout the i2 Summit program, but that the thrust of the meeting is to bring general cardiologists and interventionalists closer together, with presentations that appeal across multiple disciplines.