Even Seniors Over Age 75 Benefit from Implantable
Defibrillators; May Reduce Death Risk 30%
One of first studies to focus on senior citizens and
ICDs finds older people are good candidates for ICDs to prevent death
from arrhythmias; but benefit diminishes when age combined with multiple
disease conditions
Feb. 18, 2009 - Implantable cardioverter
defibrillators (ICDs) can improve survival in patients with heart damage
even those in their 70s according to research reported in the
current issue of Circulation: Cardiovascular Quality and Outcomes.
Implanted ICDs reduced the risk of dying by 30
percent in patients younger than 65 years old, 65 to 74, and 75 and
older, said Paul Chan, M.D., M.Sc., lead author of the study and
assistant professor at the Mid-America Heart Institute and the
University of Missouri in Kansas City.
FDA has drug in priority review; approves first
ablation catheters for the treatment of atrial fibrillation, which
affects mainly senior citizens over age 65
Although ICDs have been known to reduce mortality
in primary prevention patients with left ventricular systolic
dysfunction, recent studies have questioned their overall role in
clinical practice, especially in older patients and those with major
comorbid (more than one illness) conditions, according to the
researchers.
Patients who have damaged heart muscle that results
in diminished pumping action - called left ventricular systolic
dysfunction - are candidates for ICDs to prevent death from
life-threatening arrhythmias. The tiny devices are implanted under the
skin and connected to the heart muscle by electrodes. An ICD
automatically shocks the heart back into normal rhythm when the ICD
detects life-threatening rhythms.
Previous studies of ICDs have been conducted in
patients who are primarily younger than 75, and who have few
complications such as diabetes, chronic obstructive lung disease or a
history of stroke.
This primary prevention study recruited 986
consecutive patients who had diminished left ventricular function
meaning the pumping chamber of the heart was functioning at no more than
35 percent of capacity. Patients were treated from March 2001 though
June 2005 and followed through March 2007.
Researchers compared outcomes of 500 patients who
received ICDs to those who didnt receive the devices. The median age of
patients was 67. This was about seven years older than participants in
an earlier study that investigated the use of ICDs in patients with
heart failure (the SCD-HeFT trial) and about three years older than
participants in a study that reported on the use of ICDs in patients who
had heart attacks (the MADIT-2 trial).
Researchers said theirs was one of the first
studies to examine whether the benefits of ICDs from controlled clinical
trials apply to real-world patients. Their study was also the first to
examine a clinically well-characterized primary prevention group with
patients of both ischemic and non-ischemic causes of heart damage with
more than three years of follow-up.
We sought to determine the effectiveness of ICDs
in real-world patients who are older and have multiple co-existing
illnesses, Chan said.
Overall, 238 deaths occurred 130 (26.7 percent)
in the non-ICD group and 108 (21.6 percent) in the ICD group. Of these,
116 were attributed to arrhythmia 67 (13.7 percent) in the non-ICD
group and 49 (9.8 percent) in the ICD group.
The ICD reduced all-cause mortality by 30 percent
compared with patients who didnt receive ICDs, Chan said. The use of
ICDs in general practice reduced mortality similar to the levels seen in
clinical trials. And, the use of ICDs in older patients and patients
with comorbidities reduced mortality both in relative and absolute
terms.
When researchers studied patients age 75 or older,
they found that the level of survival benefit remained intact. But the
benefit diminished when age was combined with multiple disease
conditions.
The caveat, Chan said, was that cost effectiveness
estimates for ICD therapy in this study population depended upon both
the degree and the number of comorbidities. Chan and his colleagues
also reported in the paper cost-effectiveness estimates for the use of
ICD therapy by age and comorbidity subgroups.
The study was limited because of the relatively few
patients in their 80s. I feel comfortable applying the findings to
septuagenarians, but we continue to have limited data on ICD use among
octogenarians, Chan said.
Co-authors are Brahmajee K. Nallamothu, M.D.,
M.P.H.; John A. Spertus, M.D., M.P.H.; Frederick A. Masoudi, M.D.,
M.S.P.H; Cheryl Bartone, B.S., M.P.H.; Dean J. Kereiakes, M.D.; and
Theodore Chow, M.D. Individual author disclosures can be found on the
manuscript.
Feb. 18, 2009 - Implantable cardioverter
defibrillators (ICDs) can improve survival in patients with heart damage
even those in their 70s according to research reported in the
current issue of Circulation: Cardiovascular Quality and Outcomes.
Previous studies of ICDs have been conducted in
patients who are primarily younger than 75, and who have few
complications such as diabetes, chronic obstructive lung disease or a
history of stroke.