CLINICAL
NEWS JACC in a FLASH
Featured topics in the current and recent
issues of the JACC family of journals
Relationship Between Infarct Size
and Outcomes After PCI
In patients undergoing percutaneous coronary intervention (PCI), infarct size is strongly associated with
all-cause mortality and hospitalization for heart failure (HF) within 1
year, according to findings recently
published in JACC.
In a patient-level pooled analysis
of 10 randomized trials of PCI in
ST-segment elevation myocardial
infarction (STEMI) conducted by
Gregg W. Stone, MD, and colleagues,
2,632 patients with STEMI underwent infarct size assessment within 1
month. Infarct size was assessed by
cardiac magnetic resonance (CMR)
in 7 studies (1,889 patients, 78.1% of
the total) and by single photon emission computed tomography (SPECT)
in 3 studies (743 patients, 28.2% of
the total). The median time to infarct
size measurement was 4 days.
The median infarct size—or
percent of left ventricular myocardial mass—was 17.9%. Estimated
1-year rates of all-cause mortality,
reinfarction, and HF hospitalization
after study entry were 2.2%, 2.5%
and 2.6%, respectively. These rela-
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tionships were similar for infarct
size measured by CMR and SPECT.
Infarct size was a strong predictor of
all-cause mortality, hospitalization for
HF, and the composite occurrence of
all-cause mortality or hospitalization
for HF, but not for reinfarction. These
findings were similar in patients
without prior myocardial infarction.
The relationship between infarct size
and all-cause mortality or hospitalization for HF was consistent across
most subgroups, but was somewhat
stronger in patients with anterior
compared to non-anterior infarcts.
“Infarct size, measured by CMR
or technetium-99m sestamibi SPECT
within 1 month after primary PCI,
is strongly associated with all-cause
mortality and hospitalization for HF
within 1 year,” the study authors
note. “Infarct size may, therefore,
be useful as an endpoint in clinical
trials and as an important prognostic
measure when caring for patients
with STEMI.”
Raymond J. Gibbons, MD,
and Philip Araoz, MD, assess the
study’s strengths and weakness in
an accompanying editorial. Among
the strengths: the fact that it is a
patient-level study and that the data
are drawn from randomized trials of
primary PCI. Many of the weakness
identified by Gibbons and Araoz are
also acknowledged in the study itself.
For example, a majority of the patients had anterior infarcts, which are
larger, increasing the value of infarct
size measurement. There were also
only a “modest” number of endpoints
in the study and the authors were not
able to consider collateral flow and
ejection fraction in their analysis.
Gibbons and Araoz conclude that
the work by Stone, et al, “adds to the
scientific evidence confirming the
prognostic significance of measurements of infarct size by CMR or
SPECT prior to discharge.” They suggest that “clinicians should consider
whether infarct size will improve
their management of STEMI patients
by better identifying those with large
infarcts who should have late ejection fraction ass essment to determine
their eligibility for implantable cardioverter defibrillator placement.”
Stone GW, Selker HP, Thiele H, et al. J Am
Coll Cardiol. 2016;67(14):1674-83.
More Evidence for
Use of Bleedingavoidance
Strategies
Variations in post-percutaneous
coronary intervention (PCI) bleeding rates should not necessarily
be used as a performance measure
because a significant portion of these
variations are unexplained, asserts
a recent study published in JACC:
Cardiovascular Interventions.
Using data from ACC’s CathPCI
Registry®, researchers examined
records from almost 2.5 million procedures at 1,358 sites between 2009
and 2013 to determine whether
combinations of bleeding avoidance
strategies—use of the radial artery
for access during PCI, administering
the blood thinner bivalirudin, and
sealing off the point of access with
a vascular closure device—had an
impact on bleeding totals.
Throughout the study period,
125,361 bleeding events were observed. Overall, there was significant
variation in bleeding rates among
hospitals, ranging from 2.6% to 9.3%.
Approximately 70% of this variation
could not be attributed to any specific cause, while patient factors were
identified as the cause for 20% and use
of radial access and bivalirudin was
attributed to 7.8%.
Consistent with previous research,
the study also demonstrated the risktreatment paradox—when patients
who need an intervention the most
receive it the least frequently. Data
showed that patients receiving bleeding avoidance strategies had a predicted bleeding risk of 3.2%, compared
with a predicted bleeding risk of 4.5%
among those not receiving these strategies. Patients who had the procedure
done with radial access had less bleeding than those who did not (5% vs.
11.2%). Bivalirudin therapy was used
less frequently among patients who experienced bleeding (43.8% vs. 59.4%)
and vascular closure devices were used
at lower rates (32.9% vs. 42.4%).
The study “underscores the need
for consistent application of appropriate bleeding avoidance strategies (BAS)
in all patients,” said lead author Amit
N. Vora, MD, MPH, “especially those
at particularly high risk for bleeding
complications following PCI.” Vora noted that when hospitals used bleeding
avoidance strategies in more than 85%
of patients, bleeding rates were lower.
Given these results, Vora suggests that
broadening the use of these strategies
in all patients can not only overcome
the risk-treatment paradox but may
also be a way to reduce variation in
hospital bleeding rates.
Additionally, Vora, et al. recommend “further analyses to determine
the causes of variation in bleeding fol-
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