AHA: Heart Failure Patients Oversold on ICD Survival Benefit


implantable cardioverter defibrillatorsCHICAGO, Nov. 12 -- Cardiologists may be overselling the life-saving ability of implantable cardioverter defibrillators (ICDs) to the point that many heart failure patients refuse to let the devices be turned off, even if it would be better to do so.

In a survey at Brigham and Women's Hospital in Boston, 36% of patients with ICDs said they would never agree to turn off the defibrillator function under any circumstance, reported Garrick C. Stewart, M.D., at the American Heart Association meeting here today.

More than half would want the device kept on even if they were receiving daily shocks. Most would keep the device on if they were dying of cancer, and every single one would keep it on even if they were struggling to breathe.

Low-risk heart failure patients who were surveyed vastly overestimated the number whose lives would be saved over five years.

More than 50% said that over five years ICDs would save the lives of 50 patients for every 100 patients who received the devices, which far exceeds the real rate of seven to eight lives saved for every 100 patients implanted, Dr. Stewart said.

When heart failure patients with ICDs were asked if they believed the ICD would save their life, 67% felt their own lives were likely to be saved by the devices, and 36% thought that had already happened.

Lynne Warner Stevenson, M.D., director of the Cardiomyopathy and Heart Failure Program at Brigham and Women's and senior author of the paper, said that this optimism about the life-saving ability of the device exists in the face of the stark reality that "heart failure is a progressive, fatal disease and most patients will die slow deaths, without the device ever firing."

When physicians express the benefit of ICDs as a percentage reduction in mortality "patients don't understand that it's a percent of percent. We believe it is always better to express benefit in terms of real numbers, real patients."

She said that ICDs gained true believers among both physicians and patients when the Sudden Cardiac Death in Heart Failure in Heart Failure Trial (SCD-HeFT) reported that ICDs reduced mortality by 23% compared with patients who received only best medical treatment.

The fact that the reduction in mortality was relative not absolute, has largely been lost in translation to daily clinical practice, she said.

They surveyed 104 heart failure patients treated at Brigham and Women's Hospital. All patients had ejection fraction of less than 35% with no history of prior fainting or cardiac arrest. "They were patients who had a low risk of actually requiring defibrillation," she said.

Nonetheless, 64% already had an ICD and those who didn't, wanted one Dr. Stevenson said.

Among the findings:

  • 77% of the heart failure patients overestimated the five-year survival benefit of ICDs.
  • Belief in the life-saving ability of ICDs was the same for patients with mild heart failure symptoms as it was for those with severe symptoms.
  • 36% of patients with ICDs said they would never agree to turn off the defibrillator function.
  • 55% said they would keep the device turned on even if they were receiving daily shocks.
  • 70% said they would keep it on if they were dying of cancer.
  • 100% said they would keep it on even if they were struggling to breathe.

As a result of these unrealistic expectations many patients don't avail themselves of the opportunity to access hospice services, Dr. Stevenson said.

In an effort to provide patients with more realistic information, Dr. Stevenson has now re-written the information used to inform patients about the risks and benefits of ICDs.

"We now tell a patient that if we put an ICD in 100 patients with heart disease like yours, over the next five years we would expect 30 patients will die anyway, seven to eight will be saved by the ICD, 10-20 will have a shock when they don't need a shock, five to 15 will have other complications, and the rest of the patients will never experience a shock from their devices," she said.

Robert O. Bonow, M.D., a professor of cardiology at Northwestern Feinberg School of Medicine in Chicago, and a past president of the AHA, agreed that using absolute risk expressed in terms of "real patients" is a more accurate way to discuss the risk and benefits of devices.

Asked whether this truth-in-advertising approach has reduced the ICD implant rate at Brigham and Women's, Dr. Stevenson said "we often get patients referred to use who have been told that an ICD will save their lives, which is the wrong message to give patients."

She said that about "a third of our patients do decide to get a device, about third are persuaded that they don't need one, and the rest usually say that they want to think it over."

Dr. Stevenson said that current estimates are that 200,000 ICDs will be implanted in the U.S. this year.

source - MedPageToday