K. Soon

New scanning technique using Adaptive Statistical Iterative Reconstruction (ASIR) significantly reduced the radiation dose of cardiac CT.

The aims of our study were to evaluate the effect of application of Adaptive Statistical Iterative Reconstruction (ASIR) algorithm on the radiation dose of coronary computed tomography angiography (CCTA) and its effects on image quality of CCTA and to evaluate the effects of various patient and CT scanning factors on the radiation dose of CCTA.

External Validation of the GRACE Freedom from Events Score

AIM Acute coronary syndrome (ACS) is a common life-threatening condition but the majority of patients are at low risk of acute adverse events. In 2005, the GRACE Freedom-from-Event score (GFFES) was developed to identify patients with a low risk of adverse in-hospital events. Our aim was to externally validate this score. METHODS A prospective observational cohort of patients was admitted to a cardiology service with admission diagnoses of chest pain, unstable angina or myocardial infarction (MI). Clinical and investigational data were collected. Defined major adverse cardiac events (MACE) were death, new MI, stroke, acute pulmonary oedema, cardiac arrest or sustained ventricular tachycardia, high degree atrioventricular block, cardiogenic shock, pacemaker or intra-aortic balloon pump insertion, assisted ventilation or new acute renal failure occurring during the index admission. The primary outcome of interest was the predictive performance of the GFFES for MACE, by ROC curve and clinical performance analysis. RESULTS 238 patients were studied; median age 67, 56.7% were male. Seventy-eight patients (32.8%) were classified as low risk by the score (GFFES score≥287). There were no MACE in the low risk group. The AUC for predictive performance of the GFFES was 0.74 (95% CI 0.62-0.86). Sensitivity was 100% (95% CI 71.7-100%), specificity 34.7% (95% CI 28.5-41.3%) and negative predictive value 100% (95% CI 94.2-100%). CONCLUSION In this single site prospective validation, GFFES showed good discrimination, sensitivity and negative predictive value. It may be a useful tool for assigning patients to appropriate levels of care based on risk.

Practicality, safety and accuracy of computed tomography coronary angiography in the evaluation of low TIMI-risk score chest pain patients: A pilot study

Objectives:  The present pilot study aimed to assess the practicality, safety and accuracy of performing CT coronary angiography (CT‐CA) in the evaluation of acute chest pain of patients with low thrombolysis in myocardial infarction (TIMI) risk scores.

Non‐invasive multislice computed tomography coronary angiography for imaging coronary arteries, stents and bypass grafts

Multislice computed tomography (MSCT) is evolving rapidly and available data suggest that MSCT coronary angiography may be a reliable and accurate non‐invasive imaging modality of coronary arteries. Current generations of MSCT scanners have high sensitivity and specificity for diagnosing native coronary artery disease and coronary bypass graft occlusion. The performance of MSCT in the evaluation of stent patency is still being assessed. In comparison with conventional selective coronary angiography (SCA), MSCT is non‐invasive, cheaper and it has the advantages of imaging plaque compositions as well as assessment of luminal patency. Nevertheless, the role of MSCT in the management of coronary artery disease is yet to be fully defined.

External validation of the GRACE Freedom from Events score in an emergency department ‘rule out ACS’ chest pain cohort

follow-up. 1076 patients were included. Demographic and clinical features are shown in Table 1. 157 patients (14.6%) had a final diagnosis of MI. 14 patients (1.3%, 95% CI 0.8–2.2%) suffered a MACE. 721 patients (67%, 95% CI 64.1–69.8%) were classifi ed as low risk by the GFFES. Area under the ROC curve (AUC) for prediction of MACE at 30 days was 0.8 (95% CI 0.72–0. 89) (Fig. 1). Sensitivity was 92.8% (95% CI 64.2–99.6%), specificity was 67.8% (95% CI 64.9–70.6%) and NPV was 99.9% (95% CI 99.1–100%). The one patient that was missed at the published cut-off was a 40-year-old male with known CAD and a previous episode of AF who had negative serial biomarkers and developed a further episode of AF in thefollow-up period. Nopatienthad MI,cardiac arrest or death. 286 patients were admitted to a cardiology service (26.5%, 95% CI 24– 29.3%). Of these 132 had a low risk GFFES (46.2%, 95% CI 40.5–51.9%). One patient in this group (0.8%, 95% CI 0.1–4.2%) suffered a MACE at 30 days — the previously described patient with an episode of AF.

Multislice CT to evaluate coronary stent patency: a case report.

This is a case report on the ability of 16‐slice computed tomography in assessing the patency of coronary stent and diagnosing an asymptomatic stenotic lesion with soft plaque morphology. These findings were confirmed with a selective coronary angiography. Identification of lesion morphology facilitated our decision on prophylactic and direct stenting to the lesion.

Screening for asymptomatic coronary heart disease in the young ‘at risk’ population: Who and how?

Deaths due to coronary heart disease (CHD) remain high worldwide, despite recent achievements. An effective screening strategy may improve outcomes further if implemented in a high or ‘at risk’ cohort. Asymptomatic CHD in the young maybe underappreciated and applying an effective screening strategy to a young cohort may lead to improved outcomes due to significant socioeconomic impact from the consequences of CHD in this sub-group. A positive family history of CHD, which is known to be associated with an increased risk of future myocardial events, could aid in identifying the ‘at risk’ young cohort. Traditional cardiovascular risk scoring systems are in wide use but lack the sensitivity or specificity required to estimate risk in an individual. Rather their use is limited to predicting population attributable risk. Functional studies such as exercise stress tests are readily available and cost effective but do not have the required sensitivity required to suggest their use as part of a screening protocol. Coronary CT angiography has been demonstrated to have high sensitivity for the detection of CHD and therefore may be suitable for screening purposes but there are concerns regarding radiation exposure. Here we review the evidence for the use of potential screening strategies and the suitability of using such strategies to estimate risk of CHD in a young ‘at risk’ population.

Non-ST Elevation Myocardial Infarction with Occluded Artery and its Clinical Implications

BACKGROUND This study aimed to determine the prevalence and differences between Non-ST elevation Myocardial Infarction (NSTEMI) with an occluded culprit artery (NSTEMIOA) and NSTEMI with a patent culprit artery (NSTEMIPA). METHODS We conducted a retrospective observational study on NSTEMI patients admitted between 01/01/2010 to 30/06/2010. The inclusion criteria were diagnosis of NSTEMI and inpatient coronary angiogram. Patients were followed up for 12 months. The primary endpoints of interest were the differentiating characteristics between NSTEMIOA and NSTEMIOA. The secondary endpoints of interest were clinical outcomes in 12 months and the effect of delay in percutaneous coronary intervention on the extent of myocardial damage. RESULTS Of 143 NSTEMI patients, 34 (24%) patients had NSTEMIOA. NSTEMIOA patients had higher rates of hypercholesterolaemia (85.3% vs. 64.2%, p=0.015), ST-depression abnormality on ECGs (32.4% vs. 11.9%, p=0.008), multi-vessel disease on coronary angiogram (76.5% vs. 48.6%, p=0.004) and LV dysfunction on echo (75% vs 48%, p=0.016). At 12 months post-discharge, there was a trend of higher heart failure rate in NSTEMIOA subgroup but otherwise no difference between the two cohorts in death, myocardial infarction, revascularisation, arrhythmia, and re-admission for angina. There was no correlation between the peak CK level and the timing of percutaneous revascularisation in both cohorts. CONCLUSIONS A quarter of NSTEMI patients had an occluded culprit coronary artery. They were more likely to have hypercholesterolaemia, ECG abnormalities, multi-vessel disease and LV dysfunction.

Negative coronary CT angiography for chest pain assessment predicts low event rate in 5 years

Introduction: Coronary CT angiography (CTA) is becoming a popular investigation for chest pain. A negative coronary CTA is known to have a good negative predictive value for major adverse cardiovascular events in short term. The data on the long‐term outcomes of negative coronary CTA are lacking. We aim to investigate the long‐term prognostic value of negative coronary CTA in the evaluation of chest pain.

Prevalence of Asymptomatic Coronary Heart Disease in the Siblings of Young Myocardial Infarction Patients as Detected by Coronary Computer Tomography Angiography: A Pilot Study

BACKGROUND There is little data on the prevalence of coronary heart disease (CHD) in the young. The study aimed to estimate the prevalence of asymptomatic CHD in siblings of young patients with myocardial infarction (MI) using coronary computed tomography angiography (CCTA). METHODS Prospective observational data was collected on siblings of patients aged ≤55 years presenting with acute MI and having coronary stenosis ≥50% on invasive coronary angiography in at least one epicardial coronary artery. Inclusion criteria included ages 30-55 and 30-60 years for males and females respectively. Outcome of interest was obstructive CHD by coronary computer tomography angiography (CCTA), which was defined by either moderate (50-69% stenosis) and/or severe (≥70% stenosis). RESULTS Fifty participants were studied of whom 20 (40%) were male. Thirty (60%) were current or ex-smokers, 4 (8%) had diabetes, 8 (16%) had hypertension and 26 (52%) had dyslipidaemia. Obstructive CHD by CCTA was detected in 9 (18%, 95% CI 9%-31%) participants and 3 (6%, 95% CI 1%-17%) participants were found to have severe luminal stenosis. The median radiation dose was 3.9 (IQR 0.9) mSv. CONCLUSIONS Approximately a fifth of siblings of young MI patients were found to have asymptomatic but obstructive CHD detected on CCTA of which one third was severe. This is a group in whom screening for CHD warrants further investigation.