CLINICAL
NEWS JACC in a FLASH
Featured topics in the current and recent
issues of the JACC family of journals
‘Profound’ Overall Positive Effects
of Cardiac Rehab
Exercise-based cardiac rehab reduces
cardiovascular mortality while providing important data showing reductions in hospital admissions and improvement in quality of life, confirms
a study published Jan. 4 in JACC.
In this systematic review, researchers examined 63 studies with 14,486
patients with a follow-up of 12 months.
The exercise-based cardiac rehab
programs were usually delivered in a
supervised hospital- or center-based
setting, either exclusively or in combination with home exercise sessions.
The researchers found a reduction in cardiovascular mortality and
hospital admission with exercisebased cardiac rehab compared with
controls. There was no difference in
total mortality or the risk of fatal or
non-fatal myocardial infarction (MI),
coronary artery bypass grafting, or
percutaneous coronary intervention.
These outcomes were seen across trials regardless of patient case mix, the
nature of the cardiac rehab program,
and study characteristics.
A total of 20 studies assessed
health-related quality of life and 13
reported a higher level of quality of
life in one or more subscales following
exercise-based cardiac rehab compared
with controls; in five studies, there was
a higher level of quality of life in half
or more of the subscales. The researchers also found that exercise-based
cardiac rehab can be a cost-effective
use of health care resources.
However, the authors write that
“despite the observed improvements
in cardiovascular mortality, in a
context of contemporary coronary
heart disease medical treatments,
the opportunity for additional gains
in overall mortality with exercisebased cardiac rehab may be small.”
They add that their findings suggest
“that although cardiac rehab does not
improve coronary vascular function
or integrity, it does confer improved
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survival in patients post-MI.”
In a related editorial comment, Carl
J. Lavie, MD, and colleagues write that
these findings “[suggest] quite profound overall positive effects of cardiac
rehab programs, even if the impact on
total mortality has lessened.”
They add that there is considerable
evidence that the current model for
cardiac rehab delivery appears to be
neither financially viable nor sustainable. Additionally, despite the benefits
of cardiac rehab, only a fraction of
eligible patients are currently referred to, participate in, and complete
cardiac rehab programs. “Moving
These findings
“[suggest] quite
profound overall
positive effects
of cardiac rehab
programs, even
if the impact on
total mortality
has lessened.”
- Carl J. Lavie, et al.
forward, efforts must be made to
increase cardiac rehab program participation, which can be accomplished
by improving processes and flexibility
in the current model, creating and
implementing alternative cardiac
rehab approaches, and capitalizing on
recent technological advances.”
Automatic referral to cardiac rehab
has been adopted for many candidates,
but many patients do not attend. Endorsement from health care providers
and early initiation is important. Future
models for cardiac rehabilitation should
look beyond the current hospital-based
programs and include home-, internet-,
and community-based programs.
Lavie and colleagues conclude
that alternative secondary prevention models may help to reach a
larger patient population over an extended period of time. With changes, cardiac rehab “may transform its
impact from the individual to the
population level and re-establish, or
even improve upon, the previously
reported overall mortality benefits
of this intervention.”
Anderson L, Oldridge N, Thompson
DR, et al. JACC. 2015;doi:10.1016/j.
jacc.2015.10.044.
Obesity, Exercise,
Obstructive Sleep
Apnea: Are These
Modifiable Risk
Factors for AF?
The three pillars of atrial fibrillation
(AFib) management have long included anticoagulation, rhythm control,
and rate control. Now, a review paper
published Dec. 21 in JACC examines
the evidence supporting a fourth
pillar. Aggressive risk factor modification—especially weight loss—may
help in preventing AF as well as
manage and reduce complications in
patients with AF.
Over the last 5 years, studies
have established the close relationship between obesity and AF risk.
Body mass index (BMI) is included
in prediction models for new-onset
AF, and other adiposity measures
have also been associated with
increased AF risk. Increased BMI
is also associated with increased
left atrial size, which is associated
with higher risk of AF. Additionally ,
pericardial fat in obese individuals
is related to the presence, severity,
and post-ablation recurrence of AF,
independent of BMI. Finally, obesity
is a state of chronic systemic inflammation, which has a key role in the
occurrence of AF.
Recent studies have shown that
weight reduction has an important
role in AF management. Exercise
paired with a low-calorie diet has
shown to reduce the frequency of AF
episodes, reduce the duration of AF,
and lower the severity of symptoms.
After ablation procedures, weight
loss has demonstrated to reduce the
recurrence of AF.
Light to moderate exercise is
associated with a lower incidence in
AF compared with those who do not
exercise at all. However, this benefit
may not extend to high-intensity
exercise. In fact, studies have shown
a link between endurance exercise
and increased AF risk. Higher cardiorespiratory fitness is also associated
with a greater arrhythmia-free survival both with and without rhythmcontrol strategies. The authors write
that, given all of the cardiovascular
benefits of routine exercise, it is logical to recommend regular, moderate
exercise as part of AF prevention and
management.
Approximately half of AF patients
have obstructive sleep apnea (OSA)
and AF has a greater association
with OSA than BMI, hypertension,
and diabetes. Treatment of OSA is an
important component of AF management. According to the authors,
routine screening for OSA prior to the
use of a rhythm control strategy may
be warranted.
January 2016