CLINICAL
NEWS JOURNAL WRAP
Kim Eagle, MD, and the editors of ACC.org’s Journal Scans,
present relevant articles taken from various journals.
Studies Examine CostEffectiveness and Accuracy of
New Cholesterol Guidelines
The 2013 ACC/American Heart
Association cholesterol treatment
guidelines are associated with greater
accuracy and efficiency in identifying
increased risk of incident cardiovascular disease (CVD) events and presence
of subclinical coronary artery disease,
particularly in those at intermediate
risk, according to a study published
July 14 in the Journal of the American
Medical Association. A separate study,
also published in JAMA, verified that
the current 10-year atherosclerotic
cardiovascular disease (ASCVD) risk
threshold within the guidelines accomplished these goals with an acceptable
cost-effectiveness.
In a longitudinal community-based
cohort study on Guideline-Based Statin
Eligibility, Coronary Artery Calcification and Cardiovascular Events,
researchers observed participants
drawn from the offspring and thirdgeneration cohorts of the Framingham
Heart Study. Participants underwent
multi-detector computed tomography
for coronary artery calcification (CAC)
between 2002 and 2005, and were
followed up for a median 9.4 years for
incident CVD.
Results found that of the 2,345
statin-naïve participants, 39% were
statin eligible under the ACC/AHA
guidelines’ statin eligibility criteria
compared with 14% under the ATP
III guidelines. Participants who were
statin eligible according to ACC/AHA
guidelines also had increased hazard
ratios for incident CVD (6.8), compared to ATP III (3.1). Newly statineligible patients had an incident CVD
rate of 5.7%. Researchers also noted
that participants with CAC were more
likely to be statin eligible by ACC/AHA
guidelines than by ATP III. “In this
community-based primary prevention
cohort, we demonstrate the risk of
incident CVD among statin-eligible vs.
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noneligible participants is significantly
higher when applying the ACC/AHA
guidelines’ statin eligibility criteria
compared with the ATP III guidelines,”
the study authors write. “This finding
is consistent across subgroups and
particularly important in participants
at CVD risk.”
In the separate study looking at
the cost-effectiveness of 10-year risk
thresholds for the initiation of statin
therapy, researchers used a microsimulation model in which hypothetical
individuals from a representative U.S.
population, ranging in from 40 to 75
years of age, received statin treatment,
experienced ASCVD events and died
from ACSVD-related or non-ASCVDrelated causes based on ASCVD
natural histo ry and statin treatment
parameters. The analysis found that
the resulting health benefits of the
10-year risk threshold of 7.5% + currently used in the ACC/AHA guidelines were worth the additional costs
required in their achievement (with an
incremental cost-effectiveness ration
lower than the conservative $50,000/
quality-adjusted life-year threshold).
The research also suggests that more
lenient ASCVD risk thresholds of 3.0%
to 4.0% + represented cost-effective options. In addition to cost-effectiveness,
a projected shift from the 7.5% threshold to 3.0% to 4.0% + was associated
with an estimated additional 125,000
to 160,000 CVD events averted.
Moving forward, the study authors
suggest that future research should
consider a risk-benefit analysis focused
on costs and potential adverse effects of
statins, especially in patients with prediabetes and in lower-risk patients, in
order to provide a complete assessment
of the effects of the change in statin
eligibility guidelines on the health care
system. Additionally, researchers and
physicians should continue to analyze
the cost-effectiveness versus the number of ASCVD events prevented within
varying thresholds in order to further
the success of existing guidelines.
“Based on available evidence, including the two reports in this issue of
JAMA, answers to the questions of in
whom and how regarding cholesterol
lowering are now more clear than they
were just 18 months ago,” writes Philip
Greenland, MD, of the Northwestern
University Feinberg School of Medicine,
Chicago, and Senior Editor of JAMA,
and Michael S. Lauer, MD, of the National Heart, Lung, and Blood Institute.
“There is no longer any question as to
whether to offer treatment with statins
for patients for primary prevention, and
there should now be fewer questions
about how to treat and in whom. Rather, the next phase of research should
be directed at better ways of applying
lifestyle and drug treatments to the millions, and possibly billions, worldwide
who could potentially benefit from
a cost-effective approach to primary
prevention of ASCVD.”
Pursnani A, Massaro JM, D’Agostino RB, Sr,
et al. JAMA. 2015;314(2):134-41.
Pandya A, Sy S, Cho S, et al. JAMA.
2015;314(2):142-50.
Alcohol Consumption Causes Damage
to Older Hearts
Alcohol consumption may damage
older hearts, especially in women,
according to a recent study published
in Circulation: Cardiovascular Imaging.
While previous studies have shown
the moderate alcohol intake can be
both beneficial and detrimental to the
heart, none have examined the potential risks or benefits to cardiovascular
mechanisms.
The study assessed the association
between alcohol intake and cardiac
structure and function in elderly men
and women in the community-based
Atherosclerosis Risk in Communities
(ARIC) study, an ongoing, prospective
observational study. A total of 4,466
participants (2,685 women and 1,781
men) with a mean age of 76±5 years
were examined.
Alcohol consumption was measured by an interviewer-administered
questionnaire during each of the five
follow-up visits. Participants were
asked if they currently or had ever
been drinkers and current drinkers
were asked how often they drank
wine, beer, or liquor per week, and
then were classified into four categories according to their alcohol consumption at the last visit: nondrinkers,
drinkers of ≤7, ≥7-14, and ≥14 drinks
per week. Researchers also estimated
cumulative average alcohol intake
using data from all visits. Participants
underwent transthoracic echocardiography to measure left ventricular (LV)
dimension, wall thickness, anteriorposterior left atrial (LA) dimension,
and out-flow tract diameter.
Increasing alcohol intake was
associated with larger LV diastolic
and systolic diameter and larger LA
diameter in both men and women.
With increasing alcohol consumption,
men saw greater LV mass, higher E/E’
ratio and tricuspid annulus peak systolic velocity, and a tendency for larger
right ventricular (RV) diastolic area.
Women experienced lower LV ejection
fraction and propensity toward peak
longitudinal LV strain and increased
time to peak longitudinal LV strain.
No significant increase in LV volumes
was observed in either men or women.
With increased alcohol intake, there
was a larger LV end-diastolic diameter
and LV mass. There was also a reduction in LV wall thickness and a higher
prevalence of LV hypertrophy in men.
Women demonstrated worse LV and
RV function for any degree of alcohol
consumption compared with men.
The researchers, led by Alexandra Gonçalves, MD, PhD, suggest
the differing effects of alcohol could
be a result of women absorbing and
metabolizing alcohol differently than
men. They also note that “women
Continued on page 25
August 2015