Archive

Archive for October, 2015

Journal Club 21 October 2015

Paper

High-sensitivity cardiac troponin I at presentation in patients with suspected acute coronary syndrome: a cohort study

Presenter

SB

Summary

Summary

Background Suspected acute coronary syndrome is the commonest reason for emergency admission to hospital and is a large burden on health-care resources. Strategies to identify low-risk patients suitable for immediate discharge would have major benefits.

Methods

We did a prospective cohort study of 6304 consecutively enrolled patients with suspected acute coronary syndrome presenting to four secondary and tertiary care hospitals in Scotland. We measured plasma troponin concentrations at presentation using a high-sensitivity cardiac troponin I assay. In derivation and validation cohorts, we evaluated the negative predictive value of a range of troponin concentrations for the primary outcome of index myocardial infarction, or subsequent myocardial infarction or cardiac death at 30 days. This trial is registered with ClinicalTrials.gov (number NCT01852123).

Findings

782 (16%) of 4870 patients in the derivation cohort had index myocardial infarction, with a further 32 (1%) re-presenting with myocardial infarction and 75 (2%) cardiac deaths at 30 days. In patients without myocardial infarction at presentation, troponin concentrations were less than 5 ng/L in 2311 (61%) of 3799 patients, with a negative predictive value of 99·6% (95% CI 99·3–99·8) for the primary outcome. The negative predictive value was consistent across groups stratifi ed by age, sex, risk factors, and previous cardiovascular disease. In two independent
validation cohorts, troponin concentrations were less than 5 ng/L in 594 (56%) of 1061 patients, with an overall negative predictive value of 99·4% (98·8–99·9). At 1 year, these patients had a lower risk of myocardial infarction and cardiac death than did those with a troponin concentration of 5 ng/L or more (0·6% vs 3·3%; adjusted hazard ratio
0·41, 95% CI 0·21–0·80; p<0·0001).

Interpretation

Low plasma troponin concentrations identify two-thirds of patients at very low risk of cardiac events who could be discharged from hospital. Implementation of this approach could substantially reduce hospital admissions and have major benefi ts for both patients and health-care providers.

Supplementary Material

The editorial is available here.

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Updated AC/AHA STEMI Guidelines

The updated STEMI guidelines are available here.Note downgrading aspiration thrombectomy (no benefit in a number  of trials and possible systemic embolic hazard) and guarded incorporation multivessel PCI (PRAMI, CvLPRIT etc).

Categories: Uncategorized

ECMO, Hypothermia and Early Reperfusion in Refractory Cardiac Arrest

The use of ECMO in refractory cardiac arrest came up in discussion at Angiography meeting. This paper provided promising results. The abstract follows:

Introduction

Many patients who suffer cardiac arrest do not respond to standard cardiopulmonary
resuscitation. There is growing interest in utilizing veno-arterial extracorporeal membrane oxygenation assisted cardiopulmonary resuscitation (E-CPR) in the management of refractory cardiac arrest. We describe our preliminary experiences in establishing an E-CPR program for refractory cardiac arrest in Melbourne, Australia.

Methods

The CHEER trial (mechanical CPR, Hypothermia, ECMO and Early Reperfusion) is a single center,
prospective, observational study conducted at The Alfred Hospital. The CHEER protocol was developed for selected patients with refractory in-hospital and out-of-hospital cardiac arrest and involves mechanical CPR, rapid intravenous administration of 30 mL/kg of ice-cold saline to induce intra-arrest therapeutic hypothermia, percutaneous cannulation of the femoral artery and vein by two critical care physicians and commencement of veno-arterial ECMO. Subsequently, patients with suspected coronary artery occlusion are transferred to the cardiac catheterization laboratory for coronary angiography. Therapeutic hypothermia (33 ◦C) is maintained for 24 h in the intensive care unit.

Results

There were 26 patients eligible for the CHEER protocol (11 with OHCA, 15 with IHCA). The median
age was 52 (IQR 38–60) years. ECMO was established in 24 (92%), with a median time from collapse until initiation of ECMO of 56 (IQR 40–85) min. Percutaneous coronary intervention was performed on 11 (42%) and pulmonary embolectomy on 1 patient. Return of spontaneous circulation was achieved in 25 (96%) patients. Median duration of ECMO support was 2 (IQR 1–5) days, with 13/24 (54%) of patients successfully weaned from ECMO support. Survival to hospital discharge with full neurological recovery (CPC score 1) occurred in 14/26 (54%) patients.

Conclusions

A protocol including E-CPR instituted by critical care physicians for refractory cardiac arrest
which includes mechanical CPR, peri-arrest therapeutic hypothermia and ECMO is feasible and associated with a relatively high survival rate.

Categories: Uncategorized

Screening for Occult Cancer in Unprovoked Venous Thromboembolism

A useful paper to guide assessment of patients with unprovoked venous thromboembolism.

Summary

BACKGROUND

Venous thromboembolism may be the earliest sign of cancer. Currently, there is a
great diversity in practices regarding screening for occult cancer in a person who
has an unprovoked venous thromboembolism. We sought to assess the efficacy of
a screening strategy for occult cancer that included comprehensive computed tomography
(CT) of the abdomen and pelvis in patients who had a first unprovoked
venous thromboembolism.

METHODS

We conducted a multicenter, open-label, randomized, controlled trial in Canada.
Patients were randomly assigned to undergo limited occult-cancer screening (basic
blood testing, chest radiography, and screening for breast, cervical, and prostate
cancer) or limited occult-cancer screening in combination with CT. The primary
outcome measure was confirmed cancer that was missed by the screening strategy
and detected by the end of the 1-year follow-up period.

RESULTS

Of the 854 patients who underwent randomization, 33 (3.9%) had a new diagnosis
of occult cancer between randomization and the 1-year follow-up: 14 of the 431
patients (3.2%) in the limited-screening group and 19 of the 423 patients (4.5%)
in the limited-screening-plus-CT group (P = 0.28). In the primary outcome analysis,
4 occult cancers (29%) were missed by the limited screening strategy, whereas 5 (26%)
were missed by the strategy of limited screening plus CT (P = 1.0). There was no
significant difference between the two study groups in the mean time to a cancer
diagnosis (4.2 months in the limited-screening group and 4.0 months in the
limited-screening-plus-CT group, P = 0.88) or in cancer-related mortality (1.4% and
0.9%, P = 0.75).

CONCLUSIONS

The prevalence of occult cancer was low among patients with a first unprovoked
venous thromboembolism. Routine screening with CT of the abdomen and pelvis
did not provide a clinically significant benefit.

Categories: Uncategorized

Journal Club

Paper

Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease

Presenter

PS

Summary

BACKGROUND

In patients with coronary artery disease who receive metallic drug-eluting coronary
stents, adverse events such as late target-lesion failure may be related in part
to the persistent presence of the metallic stent frame in the coronary-vessel wall.
Bioresorbable vascular scaffolds have been developed to attempt to improve longterm
outcomes.

METHODS

In this large, multicenter, randomized trial, 2008 patients with stable or unstable
angina were randomly assigned in a 2:1 ratio to receive an everolimus-eluting
bioresorbable vascular (Absorb) scaffold (1322 patients) or an everolimus-eluting
cobalt–chromium (Xience) stent (686 patients). The primary end point, which was
tested for both noninferiority (margin, 4.5 percentage points for the risk difference)
and superiority, was target-lesion failure (cardiac death, target-vessel myocardial
infarction, or ischemia-driven target-lesion revascularization) at 1 year.

RESULTS

Target-lesion failure at 1 year occurred in 7.8% of patients in the Absorb group and
in 6.1% of patients in the Xience group (difference, 1.7 percentage points; 95%
confidence interval, −0.5 to 3.9; P = 0.007 for noninferiority and P = 0.16 for superiority).
There was no significant difference between the Absorb group and the
Xience group in rates of cardiac death (0.6% and 0.1%, respectively; P = 0.29), targetvessel
myocardial infarction (6.0% and 4.6%, respectively; P = 0.18), or ischemiadriven
target-lesion revascularization (3.0% and 2.5%, respectively; P = 0.50). Device
thrombosis within 1 year occurred in 1.5% of patients in the Absorb group and in
0.7% of patients in the Xience group (P = 0.13).

CONCLUSIONS

In this large-scale, randomized trial, treatment of noncomplex obstructive coronary
artery disease with an everolimus-eluting bioresorbable vascular scaffold, as compared
with an everolimus-eluting cobalt–chromium stent, was within the prespecified
margin for noninferiority with respect to target-lesion failure at 1 year.

Supplementary Material

ABSORB Japan trial
ABSORB China slides

Journal Club 7 October 2015

Paper

How changes to the Medicare Benefits Schedule could improve the practice of cardiology and save taxpayer money

Presenter

DC

Summary (modified from paper summary)

Rising health care costs above inflation are placing serious strains on the sustainability of the Australian Medicare system in its current structure.

The Medicare Benefits Schedule (MBS), which lists rebates payable to patients for private medical services provided on a fee-for-service basis, is the cornerstone of the Australian health care system.
Introduced in the 1980s, the MBS has changed little despite major advances in the evidence base for the practice of cardiology.

Changes to the MBS listings for four cardiac services are outlined: — invasive coronary angiography, computed tomography coronary angiography, stress testing and
percutaneous coronary intervention.

The assertions is that the proposed changes would improve the clinical practice of cardiology and save substantial amounts of taxpayer money.

Categories: Uncategorized

Journal Club 30 September 2015

Paper

Adaptive Servo-Ventilation for Central Sleep Apnea in Systolic Heart Failure

Presenter

JA

Summary

BACKGROUND

Central sleep apnea is associated with poor prognosis and death in patients with
heart failure. Adaptive servo-ventilation is a therapy that uses a noninvasive ventilator
to treat central sleep apnea by delivering servo-controlled inspiratory pressure
support on top of expiratory positive airway pressure. We investigated the effects
of adaptive servo-ventilation in patients who had heart failure with reduced ejection
fraction and predominantly central sleep apnea.

METHODS

We randomly assigned 1325 patients with a left ventricular ejection fraction of 45%
or less, an apnea–hypopnea index (AHI) of 15 or more events (occurrences of apnea
or hypopnea) per hour, and a predominance of central events to receive
guideline-based medical treatment with adaptive servo-ventilation or guidelinebased
medical treatment alone (control). The primary end point in the time-toevent
analysis was the first event of death from any cause, lifesaving cardiovascular
intervention (cardiac transplantation, implantation of a ventricular assist
device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock),
or unplanned hospitalization for worsening heart failure.

RESULTS

In the adaptive servo-ventilation group, the mean AHI at 12 months was 6.6 events
per hour. The incidence of the primary end point did not differ significantly between
the adaptive servo-ventilation group and the control group (54.1% and
50.8%, respectively; hazard ratio, 1.13; 95% confidence interval [CI], 0.97 to 1.31;
P = 0.10). All-cause mortality and cardiovascular mortality were significantly
higher in the adaptive servo-ventilation group than in the control group (hazard
ratio for death from any cause, 1.28; 95% CI, 1.06 to 1.55; P = 0.01; and hazard
ratio for cardiovascular death, 1.34; 95% CI, 1.09 to 1.65; P = 0.006).

CONCLUSIONS

Adaptive servo-ventilation had no significant effect on the primary end point in
patients who had heart failure with reduced ejection fraction and predominantly
central sleep apnea, but all-cause and cardiovascular mortality were both increased
with this therapy.

Supplementary Material

A copy of the CANPAP is available here.