American College of Cardiology

** Shock implants better than drugs alone at preventing heart-rhythm death after heart attack

(ATLANTA)—About a tenth of heart attack patients left with poor heart function will die of heart-rhythm abnormalities within two years, despite the best available drug therapy. Whether survival can be improved by the addition of an implantable defibrillator, a small device that uses shocks or other tactics to correct abnormal rhythms, has long been an unanswered question—until now.

In the second Multicenter Automatic Defibrillator Trial (MADIT-II), implantation of a defibrillator in addition to medications was associated with a 31 percent better improvement in two-year survival than was drug therapy alone in patients with prior heart attack and poor heart function.

“The findings from this trial indicate a new prophylactic approach to reducing mortality in this large group of high-risk patients with a prior heart attack,” said Dr. Arthur J. Moss of the University of Rochester in New York. Dr. Moss is scheduled to present the results of MADIT-II here on Tuesday, March 19, at 8:30 a.m. at the American College of Cardiology 51st Annual Scientific Session.

“Definitive” trial tests novel vasodilator in patients with heart failure

(ATLANTA)—A pair of large, randomized international trials should decide whether a new class of artery-dilating drugs has a future as added therapy in patients with heart failure who are already on standard medications.

The two, identically designed ENABLE trials, one conducted in North America and the other in Europe, “represents the definitive trial of ‘endothelin antagonism,’ a novel neurohormonal approach to the treatment of congestive heart failure,” according to Dr. Milton Packer, of Columbia Presbyterian Medical Center in New York City. “ENABLE” stands for ENdothelin Antagonist Bosentan for Lowering cardiac Events in heart failure.

In the two trials, patients on conventional medications for moderate-to-severe heart failure were randomly assigned also to receive either a dummy placebo pill or bosentan, an oral endothelin-receptor antagonist. The drug seemed to help such patients in early small studies.

Some artery-dilating medications improve symptoms of heart failure by expanding blood vessels, which eases the heart’s blood-pumping workload. If treatment with bosentan is found to lower patients’ risk of death or of hospitalization due to their illness, it could “change the way physicians treat congestive heart failure,” said Dr. Packer.

Dr. Packer is scheduled to announce the results of ENABLE 1 and ENABLE 2 here on Tuesday, March 19, at 8:48 a.m. at the American College of Cardiology 51st Annual Scientific Session.

(ATLANTA)—Hospitals are seeing rising numbers of patients incapacitated by very severe or “end-stage” heart failure. With demand for heart transplants far outstripping the supply of donor hearts, implantable devices that help weakened hearts pump blood have been proposed as a long-term answer. A study has determined that it is possible to identify which patients with very severe heart failure will most benefit from such implants, which are called left ventricular assist devices, or LVADs.

The REMATCH trial had previously shown that an LVAD can significantly improve survival in patients with severe heart failure who are receiving the best available treatment with medications. Further analysis of patients in REMATCH, or Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart failure, suggests those already on a particular kind of drug therapy are the ones most likely to gain benefit from an LVAD.

About 70 percent of REMATCH patients had been receiving intravenous inotropic agents, drugs that strengthen the force of heart contractions, when they enrolled in the study. “Patients who required intravenous inotropic agents to support their circulation at trial enrollment had greater benefit from LVAD implantation than patients not on inotropic infusions,” said Dr. Lynne Warner Stevenson, of Brigham and Women’s Hospital in Boston.

Dr. Stevenson is scheduled to present the results of this REMATCH analysis here on Tuesday, March 19, at 9:06 a.m. at the American College of Cardiology 51st Annual Scientific Session.

(ATLANTA)—Shortness of breath is the primary symptom for more than two-thirds of patients who present to emergency departments, but identifying the cause can be difficult and time-consuming. Now a simple, bedside blood test has proven fast and highly accurate at singling out acute heart failure as the source.

“Given the worldwide epidemic of heart failure, the test should have a broad impact on the care of patients in emergency departments,” according to Dr. Peter A. McCullough, of the University of Missouri-Kansas City School of Medicine. The bedside test measures levels of B-type natriuretic peptide, or BNP, a protein-like molecule that is released from heart muscle cells in patients with heart failure.

In the Breathing Not Properly (BNP) Multinational Study of more than 1,500 patients with shortness of breath, the bedside test significantly improved on traditional diagnostic methods for heart failure.

“It is the only test for BNP approved by the U.S. Food and Drug Administration, and the only cardiac blood test for heart failure that can be performed within 15 minutes,” said Dr. McCullough. He is slated to present the study’s results here at 9:23 a.m. on Tuesday, March 19, at the American College of Cardiology 51st Annual Scientific Session.

(ATLANTA)—A user-friendly breath analyzer that measures the chemical byproducts of tissue rejection could make the process of monitoring heart transplant patients safer and less complicated.

After a heart transplant, the recipient’s immune system normally attacks the new organ as if it were a foreign invader. Such patients, therefore, must take powerful immunity-suppressing drugs and be carefully followed for signs of transplant rejection for their entire lives. Currently the best way to detect rejection is endomyocardial biopsy, a catheter procedure in which a small bit of tissue is snipped from inside the heart and retrieved for laboratory analysis. But physicians have been seeking a safer and simpler alternative to endomyocardial biopsy, which is limited in accuracy, expensive, and invasive and could lead to infections or abnormal heart rhythms, said Dr. Michael Phillips, of Menssana Research, Inc., in Fort Lee, N.Y.

In the HARDBALL study (Heart Allograft Rejection: Detection with Breath Alkanes in Low Levels), an easy-to-use breath analyzer that measures organic compounds released by the rejection process was tested on 539 heart transplant recipients who would soon undergo biopsy. It was found that patients for whom the breath test ruled out rejection could have safely avoided having the biopsy after all, said Dr. Phillips

“The breath test could more than halve the number of biopsies heart transplant patients must undergo. It could also reduce the number of complications arising from endomyocardial biopsy and the cost of health care for these patients,” said Dr. Phillips. He is slated to present the HARDBALL study, funded by the National Heart, Lung, and Blood Institute, here on Tuesday, March 19, at 9:41 a.m. at the American College of Cardiology 51st Annual Scientific Session.

The American College of Cardiology, a 28,000-member nonprofit professional medical society and teaching institution, is dedicated to fostering optimal cardiovascular care and disease prevention through professional education, promotion of research, leadership in development of standards and guidelines, and the formulation of health care policy.

** Denotes news conference. See the news conference schedule for more information.