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Archive for October, 2013

Journal Club 23 October 2013

Paper

Feasibility of Single-Beat Full-Volume Capture Real-Time Three-Dimensional Echocardiography and Auto-Contouring Algorithm for Quantification of Left Ventricular Volume: Validation with Cardiac Magnetic Resonance Imaging

Presenter

SP

Summary

Background:

With recent developments in echocardiographic technology, a new system using real-time threedimensional
echocardiography (RT3DE) that allows single-beat acquisition of the entire volume of the left
ventricle and incorporates algorithms for automated border detection has been introduced. Provided that
these techniques are acceptably reliable, three-dimensional echocardiography may be much more useful
for clinical practice. The aim of this study was to evaluate the feasibility and accuracy of left ventricular (LV)
volume measurements by RT3DE using the single-beat full-volume capture technique.

Methods:

One hundred nine consecutive patients scheduled for cardiac magnetic resonance imaging and RT3DE
using the single-beat full-volume capture technique on the same day were recruited. LV end-systolic volume, enddiastolic
volume, and ejection fraction were measured using an auto-contouring algorithm from data acquired on
RT3DE.Thedatawerecomparedwiththe samemeasurementsobtainedusingcardiacmagnetic resonance imaging.
Results: Volume measurements on RT3DE with single-beat full-volume capture were feasible in 84% of patients.
Both interobserver and intraobserver variability of three-dimensional measurements of end-systolic
and end-diastolic volumes showed excellent agreement. Pearson’s correlation analysis showed a close correlation
of end-systolic and end-diastolic volumes between RT3DE and cardiac magnetic resonance imaging
(r = 0.94 and r = 0.91, respectively, P < .0001 for both). Bland-Altman analysis showed reasonable limits of
agreement. After application of the auto-contouring algorithm, the rate of successful auto-contouring (cases
requiring minimal man
ual corrections) was <50%.

Conclusions:

RT3DE using single-beat full-volume capture is an easy and reliable technique to assess LV volume
and systolic function in clinical practice. However, the image quality and low frame rate still limit its
application for dilated left ventricles, and the automated volume analysis program needs more development
to make it clinically efficacious.

Journal Club 16 October 2013

Paper

Predictors of normal coronary arteries at coronary angiography

Presenter

AB

Summary

Background

Coronary angiograms are important in the diagnostic workup of patients with suspected coronary artery
disease. However, little is known about the clinical predictors of normal angiograms and whether this rate varies across
different cardiac centers in Ontario.

Methods

We conducted a study using the Cardiac Care Network Variations in Revascularization Practice in Ontario
database of 2,718 patients undergoing an index cardiac catheterization for an indication of stable angina between April
2006 and March 2007 at one of 17 cardiac hospitals in Ontario. We determined predictors of normal coronary angiograms
(0% coronary stenosis) and compared rates of patients with normal catheterizations across centers.

Results

Overall, 41.9% of patients with stable angina had a normal catheterization. A multivariate model demonstrated
female gender to be the strongest predictor of a normal angiogram (odds ratio 3.55, 95% CI 2.93-4.28). In addition, atypical
ischemic symptoms or no symptoms, the absence of diabetes, hyperlipidemia, smoking history, peripheral vascular disease,
and angiography performed at a nonteaching site were associated with higher rates of normal catheterization. The rate of
normal angiograms studied varied from 18.4% to 76.9% across hospitals and was more common in community compared
with academic settings (47.1% vs 35.4%, P b .001).

Conclusions

The absence of traditional cardiac risk factors, female gender, and lack of typical angina symptoms are all
associated with a higher frequency of normal cardiac catheterizations. The wide variation in Ontario in the frequency of
normal angiograms in patients with stable angina suggests that there are opportunities to improve patient case selection.

ESC 2013 Update

A comprehensive ESC 2013 update by Dr. Atherton is available here.

Categories: Uncategorized Tags:

Journal Club 9 October 2013

Paper

Risk of Major Adverse Cardiac Events Following Noncardiac Surgery in Patients With Coronary Stents

Presenter

PJS

Summary

IMPORTANCE

Guidelines recommend delaying noncardiac surgery in patients after coronary
stent procedures for 1 year after drug-eluting stents (DES) and for 6 weeks after bare metal
stents (BMS). The evidence underlying these recommendations is limited and conflicting.
OBJECTIVE To determine risk factors for adverse cardiac events in patients undergoing
noncardiac surgery following coronary stent implantation.

DESIGN, SETTING, AND PARTICIPANTS

A national, retrospective cohort study of 41 989
Veterans Affairs (VA) and non-VA operations occurring in the 24 months after a coronary
stent implantation between 2000 and 2010. Nonlinear generalized additive models
examined the association between timing of surgery and stent type with major adverse
cardiac events (MACE) adjusting for patient, surgery, and cardiac risk factors. A nested
case-control study assessed the association between perioperative antiplatelet cessation and
MACE.

MAIN OUTCOMES AND MEASURES

A composite 30-dayMACE rate of all-cause mortality,
myocardial infarction, and cardiac revascularization.
RESULTS Within 24 months of 124 844 coronary stent implantations (47.6%DES, 52.4%
BMS), 28 029 patients (22.5%; 95%CI, 22.2%-22.7%) underwent noncardiac operations
resulting in 1980 MACE (4.7%; 95%CI, 4.5%-4.9%). Time between stent and surgery was
associated with MACE (<6 weeks, 11.6%; 6 weeks to 12-24 months, 3.5%; P < .001). MACE rate by stent type was 5.1%for BMS and 4.3%for DES
(P < .001). After adjustment, the 3 factors most strongly associated with MACE were
nonelective surgical admission (adjusted odds ratio [AOR], 4.77; 95%CI, 4.07-5.59), history
of myocardial infarction in the 6 months preceding surgery (AOR, 2.63; 95%CI, 2.32-2.98),
and revised cardiac risk index greater than 2 (AOR, 2.13; 95%CI, 1.85-2.44). Of the 12
variables in the model, timing of surgery ranked fifth in explanatory importance measured by
partial effects analysis. Stent type ranked last, and DES was not significantly associated with
MACE (AOR, 0.91; 95%CI, 0.83-1.01). After both BMS and DES placement, the risk of MACE
was stable at 6 months. A case-control analysis of 284 matched pairs found no association
between antiplatelet cessation and MACE (OR, 0.86; 95%CI, 0.57-1.29).

CONCLUSIONS AND RELEVANCE

Among patients undergoing noncardiac surgery within 2
years of coronary stent placement,MACE were associated with emergency surgery and
advanced cardiac disease but not stent type or timing of surgery beyond 6 months after stent
implantation. Guideline emphasis on stent type and surgical timing for both DES and BMS

Supplementary Material

The editorial is available here.

Journal Club 2 October 2013

Paper

Thrombus Aspiration during ST-Segment Elevation Myocardial Infarction

Presenter

YS

Summary

Background

The clinical effect of routine intracoronary thrombus aspiration before primary percutaneous
coronary intervention (PCI) in patients with ST-segment elevation myocardial
infarction (STEMI) is uncertain. We aimed to evaluate whether thrombus
aspiration reduces mortality.

Methods

We conducted a multicenter, prospective, randomized, controlled, open-label clinical
trial, with enrollment of patients from the national comprehensive Swedish
Coronary Angiography and Angioplasty Registry (SCAAR) and end points evaluated
through national registries. A total of 7244 patients with STEMI undergoing PCI were
randomly assigned to manual thrombus aspiration followed by PCI or to PCI only.
The primary end point was all-cause mortality at 30 days.

Results

No patients were lost to follow-up. Death from any cause occurred in 2.8% of the
patients in the thrombus-aspiration group (103 of 3621), as compared with 3.0% in
the PCI-only group (110 of 3623) (hazard ratio, 0.94; 95% confidence interval [CI],
0.72 to 1.22; P = 0.63). The rates of hospitalization for recurrent myocardial infarction
at 30 days were 0.5% and 0.9% in the two groups, respectively (hazard ratio,
0.61; 95% CI, 0.34 to 1.07; P = 0.09), and the rates of stent thrombosis were 0.2%
and 0.5%, respectively (hazard ratio, 0.47; 95% CI, 0.20 to 1.02; P = 0.06). There were
no significant differences between the groups with respect to the rate of stroke or
neurologic complications at the time of discharge (P = 0.87). The results were consistent
across all major prespecified subgroups, including subgroups defined according
to thrombus burden and coronary flow before PCI.

Conclusions

Routine thrombus aspiration before PCI as compared with PCI alone did not reduce
30-day mortality among patients with STEMI.