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Archive for the ‘Cardiac Imaging’ Category

Area: Height Ratio in Patients With Proximal Ascending Aortic Dilation and Trileaflet Aortic Valve

Masri et al report an observational longitudinal study of patients with proximal dilation of the ascending aorta and trileaflet aortic valves. The authors report the relationship between ascending aortic area to height ration (as assessed by CT or MRI) and clinical outcome.

Abstract

BACKGROUND:

In patients with a dilated proximal ascending aorta
and trileaflet aortic valve, we aimed to assess (1) factors independently
associated with increased long-term mortality and (2) the incremental
prognostic utility of indexing aortic root to patient height.

METHODS:

We studied consecutive patients with a dilated aortic root (≥4
cm) that underwent echocardiography and gated contrast-enhanced thoracic
aortic computed tomography or magnetic resonance angiography between
2003 and 2007. A ratio of aortic root area over height was calculated
(cm2/m) on tomography, and a cutoff of 10 cm2/m was chosen as abnormal,
on the basis of previous reports. All-cause death was recorded.

RESULTS:

The cohort comprised 771 patients (63 years [interquartile range,
53–71], 87% men, 85% hypertension, 51% hyperlipidemia, 56% smokers).
Inherited aortopathies, moderate to severe aortic regurgitation, and severe
aortic stenosis were seen in 7%, 18%, and 2%, whereas 91% and 54% were
on β-blockers and angiotensin-converting enzyme inhibitors, respectively.
Aortic root area/height ratio was ≥10 cm2/m in 24%. The Society of
Thoracic Surgeons score and right ventricular systolic pressure were 3.3±3
and 31±7 mm Hg, respectively. At 7.8 years (interquartile range, 6.6–8.9),
280 (36%) patients underwent aortic surgery (76% within 1 year) and 130
(17%) died (1% in-hospital postoperative mortality). A lower proportion of
patients in the surgical (versus nonsurgical) group died (13% versus 19%,
P<0.01). On multivariable Cox proportional hazard analysis, aortic root area/
height ratio (hazard ratio, 4.04; 95% confidence interval [CI], 2.69–6.231)
was associated with death, whereas aortic surgery (hazard ratio, 0.47;
95% CI, 0.27–0.81) was associated with improved survival (both P<0.01).
For longer-term mortality, the addition of aortic root area/height ratio ≥10
cm2/m to a clinical model (Society of Thoracic Surgeons score, inherited
aortopathies, hypertension, hyperlipidemia, medications, aortic regurgitation,
and right ventricular systolic pressure), increased the c-statistic from 0.57
(95% CI, 0.35–0.77) to 0.65 (95% CI, 0.52–0.73) and net reclassification
index from 0.17 (95% CI, 0.02–0.31) to 0.23 (95% CI, 0.04–0.34), both
P<0.01. Of the 327 patients with aortic root diameter between 4.5 and 5.5
cm, 44% had an abnormal aortic root area/height ratio, of which 78% died.

CONCLUSIONs:

In patients with dilated aortic root and trileaflet aortic
valve, a ratio of aortic root area to height provides independent and
improved stratification for prediction of death.

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Molecular Signature of Acute Myocardial infarction

An Eric Topol tweet provided public access to a very interesting paper. Candidate genes from circulating endothelial cells were identified and comparison between AMI and healthy controls. The model developed was then tested in a replication/validation set.

mami01mami02mami03

Journal Club 6 May 2015

Paper

Prognostic capabilities of coronary computed tomographic
angiography before non-cardiac surgery: prospective cohort study

Presenter

KK

Summary

Objectives

To determine if coronary computed tomographic
angiography enhances prediction of perioperative risk
in patients before non-cardiac surgery and to assess
the preoperative coronary anatomy in patients who
experience a myocardial infarction after non-cardiac
surgery.

Design

Prospective cohort study.
Setting
12 centers in eight countries.
Participants
955 patients with, or at risk of, atherosclerotic disease
who underwent non-cardiac surgery.

Interventions

Coronary computed tomographic angiography was
performed preoperatively; clinicians were blinded to
the results unless left main disease was suspected.
Results were classified as normal, non-obstructive
(<50% stenosis), obstructive (one or two vessels with
≥50% stenosis), or extensive obstructive (≥50%
stenosis in two vessels including the proximal left
anterior descending artery, three vessels, or left main).

Main outcome measure

Composite of cardiovascular death and non-fatal
myocardial infarction within 30 days after surgery
(primary outcome). This was the dependent variable in
Cox regression. The independent variables were scores
on the revised cardiac risk index and findings on
coronary computed tomographic angiography.

Results

The primary outcome occurred in 74 patients (8%). The
model that included both scores on the revised cardiac
risk index and findings on coronary computed
tomographic angiography showed that coronary
computed tomographic angiography provided
independent prognostic information (P=0.014;
C index=0.66). The adjusted hazard ratios were 1.51 (95%
confidence interval 0.45 to 5.10) for non-obstructive
disease; 2.05 (0.62 to 6.74) for obstructive disease; and
3.76 (1.12 to 12.62) for extensive obstructive disease. For
the model with coronary computed tomographic
angiography compared with the model based on the
revised cardiac risk index alone, with 30 day risk
categories of 15% for the primary
outcome, the results of risk reclassification indicate that
in a sample of 1000 patients that coronary computed
tomographic angiography would have resulted
appropriately in 17 net patients receiving a higher risk
estimation among the 77 patients who would have
experienced the primary outcome (P<0.001). Coronary
computed tomographic angiography, however, would
have resulted inappropriately in 98 net patients
receiving a higher risk estimation, among the 923
patients who would not have experienced the primary
outcome (P<0.001). Among patients who had a
perioperative myocardial infarction, preoperative
coronary anatomy showed extensive obstructive disease
in 31% (22/71), obstructive disease in 41% (29/71),
non-obstructive disease in 24% (17/71), and normal
findings in 4% (3/71).

Conclusions

Though findings on coronary computed tomographic
angiography can improve estimation of risk for
patients who will experience perioperative
cardiovascular death or myocardial infarction, findings
are more than five times as likely to lead to an
inappropriate overestimation of risk among patients
who will not experience these outcomes. Perioperative
myocardial infarction occurs across the spectrum of
coronary artery disease, suggesting that there could be
several pathophysiologic mechanisms.

Journal Club 4 Decembe 2013

Paper

Optimized Prognostic Score for Coronary Computed Tomographic Angiography Results From the CONFIRM Registry (COronary CT Angiography EvaluatioN For Clinical Outcomes: An InteRnational Multicenter Registry)

Presenter

JFY

Summary

Objectives

The aim of this study was to analyze the predictive value of coronary computed tomography angiography (CCTA) and
to model and validate an optimized score for prognosis of 2-year survival on the basis of a patient population with
suspected coronary artery disease (CAD).
Background Coronary computed tomography angiography carries important prognostic information in addition to the detection of
obstructive CAD. But it is still unclear how the results of CCTA should be interpreted in the context of clinical risk
predictors.

Methods

The analysis is based on a test sample of 17,793 patients and a validation sample of 2,506 patients, all with
suspected CAD, from the international CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes: An
InteRnational Multicenter) registry. On the basis of CCTA data and clinical risk scores, an optimized score was
modeled. The endpoint was all-cause mortality.

Results

During a median follow-up of 2.3 years, 347 patients died. The best CCTA parameter for prediction of mortality was
the number of proximal segments with mixed or calcified plaques (C-index 0.64, p 50% (C-index 0.56, p ¼ 0.002). In an optimized score including both
parameters, CCTA significantly improved overall risk prediction beyond National Cholesterol Education Program
Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III)
score as best clinical score. According to this score, a proximal segment with either a mixed or calcified plaque or
a stenosis >50% is equivalent to a 5-year increase in age or the risk of smoking.

Conclusions

In CCTA, both plaque burden and stenosis, particularly in proximal segments, carry incremental prognostic value. A
prognostic score on the basis of this data can improve risk prediction beyond clinical risk scores.

Supplementary Related Material

Editorial by Dr. J. Younger
Template of risk score
CT aggregate plaque volume to assess hemodynamic significance of intermediate lesions

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.

Aortopathy

Some recent papers in Heart Lung and Circulation are hyperlinked below.

 

aortopathy_01

aortopathy_02

aortopathy_03

 

Journal Club 8 August 2012

Paper

Coronary CT Angiography versus Standard Evaluation in Acute Chest Pain

Presenter

JFY

Summary (abstract from paper)

Background

It is unclear whether an evaluation incorporating coronary computed tomographic
angiography (CCTA) is more effective than standard evaluation in the emergency
department in patients with symptoms suggestive of acute coronary syndromes.

Methods

In this multicenter trial, we randomly assigned patients 40 to 74 years of age with
symptoms suggestive of acute coronary syndromes but without ischemic electrocardiographic
changes or an initial positive troponin test to early CCTA or to standard
evaluation in the emergency department on weekdays during daylight hours between
April 2010 and January 2012. The primary end point was length of stay in the hospital.
Secondary end points included rates of discharge from the emergency department,
major adverse cardiovascular events at 28 days, and cumulative costs. Safety
end points were undetected acute coronary syndromes.

Results

The rate of acute coronary syndromes among 1000 patients with a mean (±SD) age
of 54±8 years (47% women) was 8%. After early CCTA, as compared with standard
evaluation, the mean length of stay in the hospital was reduced by 7.6 hours
(P<0.001) and more patients were discharged directly from the emergency department
(47% vs. 12%, P<0.001). There were no undetected acute coronary syndromes
and no significant differences in major adverse cardiovascular events at 28 days.
After CCTA, there was more downstream testing and higher radiation exposure.
The cumulative mean cost of care was similar in the CCTA group and the standardevaluation
group ($4,289 and $4,060, respectively; P = 0.65).

Conclusions

In patients in the emergency department with symptoms suggestive of acute
coronary syndromes, incorporating CCTA into a triage strategy improved the efficiency
of clinical decision making, as compared with a standard evaluation in the
emergency department, but it resulted in an increase in downstream testing and
radiation exposure with no decrease in the overall costs of care.

Comments

There was general discussion around different diagnostic algorithms, definitions of acceptable risk, various accelerated diagnostic protocols, radiation exposure and stochastic risk (esp. cumulative exposures and ‘vulnerable’ group). [Cardiology and Emergency Physician input]

The editorial is available here