Saturday, April 1, 2023
ACC 2012 Research Highlights
The American College of Cardiology (ACC) 2012 Scientific Sessions took place in Chicago, Illinois, from March 24-27, 2012. Key trials presented at the sessions include:
TRA 2°P -- TIMI 50: Possible future for vorapaxar in patients with prior myocardial infarction (MI)
PARTNER A: Paravalvular leaks linked with higher mortality at 2 years in TAVI trial
STAMPEDE: Bariatric surgery is better than standard diabetes treatment in obese patients
ROMICAT II/ACRIN-PA: CT-first acute coronary syndrome (ACS) strategy matches current practice and safely discharges more patients
EINSTEIN-PE: Rivaroxaban equals standard therapy, halves major bleeding
ASCERT: Coronary artery bypass graft (CABG) vs percutaneous coronary intervention (PCI): Lower mortality with surgery
ISSUE-3: DDD pacing can help suppress asystolic neurally mediated syncope (NMS)
C-PORT E: 9-month results: Elective PCI doesn't need surgical safety net
CORONARY: Off-pump and on-pump CABG give similar short-term outcomes
Mendelian RCT: Lowering low-density lipoprotein (LDL) cholesterol early in life has the potential to reduce coronary heart disease
Possible future for vorapaxar in patients with prior MI
Full results of the TRA 2°P -- TIMI 50 study suggest that the novel antiplatelet agent vorapaxar seems to have a net clinical benefit in selected secondary-prevention patients. Patients who did best on the drug were those with a prior MI and no history of stroke or transient ischemic attack and who weighed more than 60 kg. But many observers expressed concerns about the bleeding risk with the drug, with suggestions that it may not be suitable for general availability. The top-line results of the trial, announced earlier this year, reported that vorapaxar, which blocks the protease-activated receptor 1 on platelets, was successful in reducing the primary ischemic endpoint of the study, but at the cost of increased bleeding, including intracranial hemorrhage.
"There are definitely some important -- even practice-changing -- messages from this trial. The most compelling benefits were seen in the subgroup of patients with previous MI, where we saw a 20% reduction in the primary endpoint of cardiovascular death/MI/stroke," said lead study investigator David Morrow.
Paravalvular leaks linked with higher mortality at 2 years in TAVI trial
Paravalvular leaks -- a phenomenon virtually unheard of in the era of surgical valve replacement -- were propelled into the limelight at the ACC 2012 Scientific Sessions, with the presentation of 2-year results from the PARTNER A transcatheter aortic-valve intervention trial. At 2 years, rates of death from any cause did not statistically differ between transcatheter aortic-valve replacement (TAVR) and surgical valve replacement, but paravalvular regurgitation was more common after TAVR than surgery. Strikingly, even mild paravalvular regurgitation was associated with increased late mortality.
"This is an important observation, but I would put it in perspective. If you look at overall mortality between surgery and TAVR, the rates are identical, and in no subgroup is overall mortality different," said Dr. Martin Leon (Columbia University, New York, New York). "We're thinking that paravalvular leak can be treated or prevented, and there's clear evidence that there was valve undersizing in PARTNER that we think can be corrected using postdilatation if done selectively and carefully. If you can reduce the incidence of paravalvular leak down to 'none or trace,' you could potentially reduce mortality by half."
Bariatric surgery is better than standard diabetes treatment in obese patients
In the STAMPEDE trial, 150 obese patients (body mass index 27-43 kg/m2) with uncontrolled type 2 diabetes were randomly assigned to receive medical therapy, Roux-en-Y gastric bypass (RYGB), or sleeve gastrectomy. Mean age was 49 years, and mean A1c was 9.2%. The main study outcome of A1c of 6.0% or less after 12 months of treatment was met by 12% of the medical therapy group, 42% of the RYGB group (P = .002 vs medical therapy), and 37% of the sleeve gastrectomy group (P = .008 vs medical therapy). Although glycemic control improved in all 3 groups, improvements were significantly greater in the surgical groups, as was weight loss and improvement in insulin resistance.
"There was quite a large difference between the surgical and medical group in terms of the success rate," said Dr. Philip Schauer. "All of the gastric bypass patients who reached an A1c of 6.0% or less did so without any medication; they were weaned off all antidiabetic agents, including insulin, to reach that target." They were also able to reduce use of cardiovascular medication, he noted. "That's as close to a definition of remission that you can get. And the sleeve gastrectomy group was pretty close as well."
CT-first ACS strategy matches current practice and safely discharges more patients
The coronary CT angiography (CCTA)-based strategy for screening patients with chest pain in the emergency department is safe and reduces overall patient time in the hospital. ROMICAT II results show that costs are about the same overall as the current standard approach. According to the results of ACRIN-PA, CCTA screening also allows more patients without ACS to be discharged safely than does standard screening practice.
"The reason we do all of this testing is because we want to drive the miss rate below 1%. The reason we want to drive the miss rate below 1% is obvious, but what is not obvious is that there are gobs and gobs and gobs of clinical studies of 10,000 to 20,000 [patients] that show that when we use clinical judgment alone, we stink. We can use judgment to drive the miss rate down to about 5%, but going from that 5% to less than 1% cannot possibly be done just with clinical judgment," said ACRIN-PA co-investigator and emergency physician Dr. Judd Hollander (University of Pennsylvania, Philadelphia).
Rivaroxaban equals standard therapy, halves major bleeding
According to the results of EINSTEIN-PE, the new oral anticoagulant rivaroxaban is at least as effective for the treatment of pulmonary embolism as the standard therapy of injected low-molecular-weight heparin followed by warfarin. The study was reported at the ACC 2012 Scientific Sessions and simultaneously published online in New England Journal of Medicine.
"We want to make life easier," said Dr. Harry Büller, noting that many physicians and patients hate the monitoring that is required with warfarin and similar agents. "Pulmonary embolism is a disease that occurs in all ages, and therefore having a strategy with a pill and no monitoring is, I believe, a small revolution."
CABG vs PCI: Lower mortality with surgery
Adjusted 4-year all-cause mortality was about 20% lower after CABG than after PCI in an observational study of about 190,000 patients in the United States who underwent nonemergent revascularization for 2- or 3-vessel coronary disease. Mortality at 1 year was similar for the 2 procedures. Based on data from patients older than 65 years in 2 large society-sponsored databases, the analysis used several methods to control for risk levels and other influences on outcomes. It found that the long-term advantage for CABG was independent of age, sex, diabetes, renal function, and lung disease and was evident "even among patients whose propensity scores were most consistent with selection for PCI."
"That was one of the major surprises in the study. We really thought we'd find subsets of patients that would benefit from surgery and other subsets that would benefit from percutaneous intervention," said surgeon Dr. Fred H. Edwards (University of Florida, Jacksonville), co-principal investigator of the trial with Dr. Weintraub. "And much to our surprise, all of the subsets showed a survival advantage for surgery."
DDD pacing can help suppress asystolic NMS
Contrary to previous clinical trials that suggested otherwise, pacemaker therapy can cut the risk for fainting spells in patients with demonstrated asystolic NMS, according to the investigators of ISSUE-3, a randomized, controlled trial. Pacing therapy succeeded in their trial at least in part because unlike in the other trials, patients were required to have demonstrated asystolic NMS at implantable loop-recorder screening, said principal investigator Dr. Michele Brignole (Ospedali del Tigullio, Lavagna, Italy). The trial was conducted at 29 centers in Canada and Western Europe.
"The point is that in these patients, there has been no [treatment] with proven efficacy for this form [of syncope] before this trial," said Dr. Brignole. With the results of ISSUE-3, according to Dr. Brignole, "the efficacy of pacing is established" without the need for replication in further trials.
The Heart of Innovation Featured Learning DestinationTM
The Heart of Innovation explored the evolution of the standard of care for coronary artery disease and heart failure caused by valvular disease through the lenses of 4 main areas: personalized medicine, technobiology, minimally invasive therapies, and physician/patient engagement.
Topics covered included:
• Insights into how genetic research is rapidly transforming ways to prevent, diagnose, and treat patients;
• How revolutionary ideas, such as growing heart valves, are being transformed into real possibilities, thanks to strides in stem-cell research;
• How such innovations as mobile apps are changing the relationship between cardiologists and patients; and
• The newest minimally invasive techniques, implantable devices, multimodality imaging, dose-reduction solutions, and robotic surgical tools.
As part of the presentation, the Thought Leader Theater featured presentations and panel discussions from world-renowned physicians, scientists, and academics on topics from these 4 areas.
9-month results: Elective PCI doesn't need surgical safety net
C-PORT E, a 9-month randomized trial, compared elective PCI at centers without and with on-site cardiac surgery. Results suggest that patients fare about the same, regardless of whether PCI has the surgical safety net. At 9 months, the composite rates of death from any cause, Q-wave MI, and target-vessel revascularization were 12.1% without on-site surgery and 11.2% with backup surgery in this noninferiority trial. Previously reported 6-week mortality was 0.9% and 1.0%, respectively, which also met the trial's criterion for noninferiority.
"In C-PORT, we didn't perceive angioplasty as a procedure that occurs [just] in the cardiac cath lab. We thought of it as a strategy of care for coronary artery disease, with the hospital component of that strategy implemented in the emergency room, the cardiac cath lab, the coronary care unit, and in any step-down unit to which the patient may be transferred," said Dr. Thomas Aversano.
Off-pump and on-pump CABG give similar short-term outcomes
CORONARY, the largest study ever to compare off-pump and on-pump CABG, has shown no significant difference in 30-day results for the primary endpoint. Some differences in secondary endpoints may drive decisions on an individual basis until long-term results are available, suggests lead investigator Dr. André Lamy.
"Our study should settle the current controversy surrounding off-pump surgery," said Dr. Lamy. "The recent results suggesting worse outcomes with this approach were probably due to inexperienced surgeons. As off-pump [surgery] is more technically challenging, you need to be more experienced for this approach, but if the surgeon is comfortable with off-pump [surgery], the results seem to be good."
Lowering LDL cholesterol early in life has the potential to reduce coronary heart disease
Mendelian, a randomized, controlled trial, suggests that lowering LDL cholesterol early in life has the potential to reduce coronary heart disease to a far greater extent than starting treatment later in life -- the current standard practice. To estimate the clinical benefit of lowering LDL cholesterol early in life, study investigators used 9 single nucleotide polymorphisms (SNPs) from 6 genes associated with lower LDL cholesterol levels as a proxy for a treatment that causes this lowering beginning at birth. All 9 SNPs were associated with a consistent 54% reduction in the risk for the primary endpoint (a composite of cardiovascular death, MI, and coronary revascularization) for each 1-mmol/L (38.7-mg/dL) lower lifetime exposure to LDL cholesterol.
"We are not suggesting that everyone take statins from childhood -- rather, that lowering LDL through more attention to healthy diet and exercise from a young age could make a big difference to public health," commented lead author Dr. Brian Ference.
Credits and disclosures
Editor:
Shelley Wood
Managing Editor, heartwire
theheart.org
Kelowna, British Columbia, Canada
Disclosure: Shelley Wood has disclosed no relevant financial relationships.
Contributors:
Steven Rourke
Manager, Editorial Programming
theheart.org
Montreal, Quebec, Canada
Disclosure: Steven Rourke has disclosed no relevant financial relationships.
Maria Turner
Freelance writer
Montreal, Quebec, Canada
Disclosure: Maria Turner has disclosed no relevant financial relationships.
Journalists:
Sue Hughes
theheart.org
London, United Kingdom
Disclosure: Sue Hughes has disclosed no relevant financial relationships.
Reed Miller
theheart.org
State College, Pennsylvania
Disclosure: Reed Miller has disclosed no relevant financial relationships.
Lisa Nainggolan
theheart.org
London, United Kingdom
Disclosure: Lisa Nainggolan has disclosed no relevant financial relationships.
Michael O'Riordan
theheart.org
Toronto, Ontario, Canada
Disclosure: Michael O'Riordan has disclosed no relevant financial relationships.
Steve Stiles
theheart.org
Fremont, California
Disclosure: Steve Stiles has disclosed no relevant financial relationships.
