Utilizing Fish Skin of Ikan Belida (Notopterus lopis) as a Source of Collagen: Production and Rheology Properties.

Collagen hydrogels have been extensively applied in biomedical applications. However, their mechanical properties are insufficient for such applications. Our previous study showed improved mechanical properties when collagen was blended with alginate. The current study aims to analyze the physico-chemical properties of collagen-alginate (CA) films such as swelling, porosity, denaturation temperature (Td), and rheology properties. Collagen was prepared from discarded fish skin of Ikan Belida (Notopterus lopis) that was derived from fish ball manufacturing industries and cross-linked with alginate from brown seaweed (Sargasum polycystum) of a local species as a means to benefit the downstream production of marine industries. CA hydrogels were fabricated with ratios (v/v) of 1:1, 1:4, 3:7, 4:1, and 7:3 respectively. FTIR spectrums of CA film showed an Amide I shift of 1636.12 cm-1 to 1634.64 cm-1, indicating collagen-alginate interactions. SEM images of CA films show a porous structure that varied from pure collagen. DSC analysis shows Td was improved from 61.26 °C (collagen) to 83.11 °C (CA 3:7). CA 4:1 swelled nearly 800% after 48 h, correlated with the of hydrogels porosity. Most CA demonstrated visco-elastic solid characteristics with greater storage modulus (G') than lost modulus (G″). Shear thinning and non-Newtonian behavior was observed in CA with 0.4% to 1.0% (w/v) CaCl2. CA hydrogels that were derived from discarded materials shows promising potential to serve as a wound dressing or ink for bio printing in the future.

Diabetes mellitus is independently associated with early stent thrombosis in patients undergoing drug eluting stent implantation: Analysis from the Victorian cardiac outcomes registry.

BACKGROUND: Diabetes mellitus (DM) is a predictor of restenosis and late stent thrombosis (ST) in patients undergoing percutaneous coronary intervention (PCI) with drug-eluting-stents (DES). Real-world data on rates of early ST is lacking. We compared clinical outcomes of patients with and without DM from the Victorian cardiac outcomes registry. METHODS: Consecutive patients undergoing PCI with DES were analyzed with primary outcome being ST at 30-days. Secondary outcomes including major adverse cardiovascular events (MACE) and all-cause mortality. RESULTS: Of 43,209 patients included, 9730 (22.5%) had DM. At 30 days, DM was independently associated with higher rates of early ST (0.7% vs. 0.5%) OR 1.41 (95% confidence interval; 1.05-1.87, p = 0.02), MACE (4.1% vs. 3.5%, p = 0.004) and mortality (1.9% vs. 1.5%, p = 0.01). Increased risk was not simply due to treatment. Patients with DM requiring insulin were equally affected in regard to MACE (4.7% vs. 3.9%, p = 0.069) and mortality (1.9%, vs. 1.8%, p = 0.746). On National Death Index linkage, patients with DM had increased all-cause mortality over five-year follow-up (OR 1.69 CI 1.55-1.83, p = < 0.001). CONCLUSION: In this large real-world-registry, DM was an independent predictor of early ST, MACE and mortality at 30 days. These data suggest additional therapeutic strategies are required to reduce the risk of early complications in patients with DM undergoing PCI with DES.

The assessment of intermediate coronary lesions using intracoronary imaging.

Intermediate coronary artery stenosis, defined as visual angiographic stenosis severity of between 30-70%, is present in up to one quarter of patients undergoing coronary angiography. Patients with this particular lesion subset represent a distinct clinical challenge, with operators often uncertain on the need for revascularization. Although international guidelines appropriately recommend physiological pressure-based assessment of these lesions utilizing either fractional flow reserve (FFR) or quantitative flow ratio (QFR), there are specific clinical scenarios and lesion subsets where the use of such indices may not be reliable. Intravascular imaging, mainly utilizing intravascular ultrasound (IVUS) and optical coherence tomography (OCT) represents an alternate and at times complementary diagnostic modality for the evaluation of intermediate coronary stenoses. Studies have attempted to validate these specific imaging measures with physiological markers of lesion-specific ischaemia with varied results. Intravascular imaging however also provides additional benefits that include portrayal of plaque morphology, guidance on stent implantation and sizing and may portend improved clinical outcomes. Looking forward, research in computational fluid dynamics now seeks to integrate both lesion-based physiology and anatomical assessment using intravascular imaging. This review will discuss the rationale and indications for the use of intravascular imaging assessment of intermediate lesions, while highlighting the current limitations and benefits to this approach.

LV systolic dysfunction stands to gain the most post transcatheter aortic valve implantation (TAVI).

Aims: We aimed to evaluate the extent of left ventricular (LV) recovery post transcatheter aortic valve implantation (TAVI) and its clinical predictors. Methods and results: This was a retrospective study on patients treated with TAVI from August 2008 to September 2017. Patients were sub-classified according to their baseline LV function as normal, mildly impaired, moderately impaired or severely impaired. Echo pre TAVI and early post TAVI were compared to assess LV function change. Predictors of LV function change were sought from univariate and multivariate ordinal logistic regression analyses. There were 662 patients included in this study. Nearly half of them, 323 patients (49%), had abnormal LV systolic dysfunction of various degrees. Of these, 193 (60%) showed LV function improvement post TAVI. Based on their pre-TAVI LV function, 55% of the mild LV dysfunction cohort, 62% of the moderate LV dysfunction cohort and 74% of the severe LV dysfunction cohort had LV function improvement post TAVI. Multivariate logistic regression analysis revealed baseline LV dysfunction as the only significant predictor of LV function improvement post TAVI. Conclusions: The majority of patients with baseline LV dysfunction had LV improvement post TAVI, more so those patients with severe LV dysfunction.

Biodegradable-Polymer Versus Polymer-Free Drug-Eluting Stents for the Treatment of Coronary Artery Disease.

BACKGROUND/PURPOSE: Biodegradable-polymer (BP) and polymer-free (PF) drug eluting stents (DES) were developed to reduce the risk of delayed arterial healing observed with durable-polymer (DP) platforms. Although trials demonstrate BP-DES and PF-DES are non-inferior to DP-DES, there is limited data directly comparing these technologies. We performed a meta-analysis to assess the efficacy and safety of BP-DES versus PF-DES for the treatment of coronary artery disease. METHODS/MATERIALS: Electronic searches were performed identifying randomized trials comparing BP-DES with PF-DES. Co-primary efficacy endpoints were target vessel revascularization (TVR), target lesion revascularization (TLR) and angiographic in-stent late lumen loss (LLL). Co-secondary safety endpoints were all-cause death, myocardial infarction (MI) and stent thrombosis (ST). RESULTS: Of 208 studies, 5 met inclusion criteria including 1975 patients. At mean follow-up (14 ±â€¯5 months), BP-DES were associated with significantly reduced rates of TVR (OR 0.58, 95%CI 0.37-0.92, p = 0.02), TLR (4.7% vs 9.5%) (OR 0.48, 95%CI 0.31-0.75, p = 0.001) and in-stent LLL (pooled mean difference -0.20 mm, 95%CI -0.24 to -0.16, p < 0.001). There was no difference in safety, including all-cause death (OR 1.24, 95%CI 0.68-2.28, p = 0.48), MI (OR 0.92, 95%CI 0.54-1.56, p = 0.75) or ST (OR 1.58, 95%CI 0.67-3.73, p = 0.30). CONCLUSIONS: These data suggests that BP-DES are more efficacious when compared with PF-DES for the treatment of CAD.

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.

Myocardial Infarction in the "Young": Risk Factors, Presentation, Management and Prognosis.

Myocardial infarction (MI) in the "young" is a significant problem, however there is scarcity of data on premature coronary heart disease (CHD) and MI in the "young". This may lead to under-appreciation of important differences that exist between "young" MI patients versus an older cohort. Traditional differences described in the risk factor profile of younger MI compared to older patients include a higher prevalence of smoking, family history of premature CHD and male gender. Recently, other potentially important differences have been described. Most "young" MI patients will present with non-ST elevation MI but the proportion presenting with ST-elevation MI is increasing. Coronary angiography usually reveals less extensive disease in "young" MI patients, which has implications for management. Short-term prognosis of "young" MI patients is better than for older patients, however contemporary data raises concerns regarding longer-term outcomes, particularly in those with reduced left ventricular systolic function. Here we review the differences in rate, risk factor profile, presentation, management and prognosis between "young" and older MI patients.

Percutaneous Coronary Intervention of an Anomalous Left Main Coronary Artery Arising from the Right Sinus of Valsalva.

Anomalous origination of a coronary artery from the opposite sinus of Valsalva is an uncommon congenital anomaly. Intervention for concurrent coronary artery disease is challenging due to the location of the ostia, the takeoff of the vessel as well as the course of the artery in question. It is also important, where possible, to exclude a "malignant" course as the most common adverse outcome from this anomaly is that of sudden cardiac death. Here we present a case of percutaneous coronary intervention in a patient with anomalous left main origination from the right coronary sinus of Valsalva and a brief discussion on the subject.

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.

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

INTRODUCTION: 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. METHODS: This was a retrospective study that included 347 consecutive patients who underwent CCTA at a tertiary university teaching hospital between 1 July 2009 and 20 September 2011. Analysis was performed comparing patient demographics, scan characteristics, radiation dose and image quality in two groups of patients in whom conventional Filtered Back Projection (FBP) or ASIR was used for image reconstruction. RESULTS: There were 238 patients in the FBP group and 109 patients in the ASIR group. There was no difference between the groups in the use of prospective gating, scan length or tube voltage. In ASIR group, significantly lower tube current was used compared with FBP group, 550 mA (450-600) vs. 650 mA (500-711.25) (median (interquartile range)), respectively, P < 0.001. There was 27% effective radiation dose reduction in the ASIR group compared with FBP group, 4.29 mSv (2.84-6.02) vs. 5.84 mSv (3.88-8.39) (median (interquartile range)), respectively, P < 0.001. Although ASIR was associated with increased image noise compared with FBP (39.93 ± 10.22 vs. 37.63 ± 18.79 (mean ± standard deviation), respectively, P < 0.001), it did not affect the signal intensity, signal-to-noise ratio, contrast-to-noise ratio or the diagnostic quality of CCTA. CONCLUSION: Application of ASIR reduces the radiation dose of CCTA without affecting the image quality.

Angiographic and clinical outcomes of stent postdilatation in ST-elevation myocardial infarction.

INTRODUCTION: Stent postdilatation is commonly performed to optimise stent deployment during percutaneous coronary intervention (PCI). However, it is controversial in the setting of acute myocardial infarction (AMI) due to the theoretically increased risk of thrombus embolization causing no-reflow. This study aimed to evaluate the immediate angiographic effects and long-term clinical outcomes of stent postdilatation in the setting of ST-elevation myocardial infarction (STEMI). METHODS: This was a single-centre retrospective observational study involving patients who presented with STEMI and received primary PCI, from July 2009 till June 2010. The angiographic endpoints were final TIMI coronary flow (TMF) and TIMI myocardial perfusion (TMP) score. The clinical endpoint was a composite endpoint of major adverse cardiac events (MACEs) i.e. AMI, target vessel revascularisation or cardiac death at one, six and twelve months after PCI. RESULTS: One hundred and sixty patients with a mean age of 62 years were included in this study. Seventy-one patients (44.4%) had stent postdilatation and 89 patients (55.6%) did not. Patient demographics, risk factors, clinical presentation and baseline angiographic and procedural characteristics, were similar among these two subgroups. There was also no significant difference in the proportions of patients achieving grade III in final TMF (60/71 vs. 74/89, respectively, p>0.05) and final TMP (52/71 vs. 64/89, respectively, p>0.05), as well as the MACE-free survival probability by Kaplan-Meier estimate (85.1% vs. 86.9%, p=0.95), between the two subgroups. CONCLUSION: Stent postdilatation does not seem to have any detrimental effects on patients' final angiographic results and long-term clinical outcomes, in the setting of STEMI.

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.

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. METHODS: This was a retrospective observational study involving 259 cases of coronary CTA on our registry from July 2004 to November 2006. All coronary CTA were performed with GE 16-slice CT and then GE 64-slice CT scanner in late 2006. A negative coronary CTA was defined as no single coronary segment with stenosis ≥50% based on American Heart Association 16-segment model. The end point of the study was defined as a composite of major cardiovascular events such as myocardial infarction, myocardial death or revascularisation. RESULTS: Seventy cases of 259 on the registry were diagnosed as negative studies. Mean follow-up period was 4.64 ± 0.6 years (range from 3.4 to 5.7 years). Of these negative studies, only one patient suffered from the end point during the follow-up. Thus, the negative predictive value of a negative coronary CTA for a long-term major cardiovascular event was 0.986 (95% confidence interval: 0.92-0.99). CONCLUSIONS: A negative coronary CTA in patients with a low or intermediate pretest probability for significant coronary artery disease predicts a low rate of major cardiovascular events within a 5-year period.

Adjunctive balloon dilatation after stent deployment: beneficial or deleterious?

The practice of adjunctive balloon post-dilatation is not consistent among interventionalists, particularly in the setting of acute myocardial infarction (AMI). There have been some concerns about the risks of adjunctive balloon post-dilatation, particularly in the setting of acute coronary syndrome (ACS). This review will examine the data on the angiographic and clinical effects, and the risks of adjunctive balloon post-dilatation of stents in the treatment of coronary artery disease.

Diagnostic and prognostic significance of plasma N-terminal-pro-brain natriuretic peptide in decompensated heart failure with preserved ejection fraction.

BACKGROUND: Preserved ventricular function is increasingly recognised in CHF. Although, NTpro-BNP is a well-established diagnostic marker in heart failure with impaired EF, its significance in heart failure with preserved EF is unclear. NT pro-BNP is secreted from the ventricular wall and plasma levels correlate to ventricular function. This study sought to determine the diagnostic and prognostic significance of plasma NTpro-BNP in patients with preserved EF heart failure. METHODS: We recruited 133 consecutive patients with decompensated HF. The primary end point was death or hospital readmission. RESULTS: Median (IQR) NTpro-BNP level at admission was elevated at 5043 ng/L (2693-10,784) and was significantly lower in preserved EF, 3569 ng/L (1707-6340) than in impaired EF, 6363 ng/L (3648-13,250) (P=0.001). Eight (6%) and 19 (14%) patients died after 1 and 6 months, respectively. In a regression analysis, worsening of NTpro-BNP levels after treatment was not predictive of mortality in heart failure with preserved EF (P=0.83). Levels at discharge correlated with readmission rates at 6 months in both groups, i.e. impaired (P=0.03) and preserved EF (P=0.02). CONCLUSION: NTpro-BNP is a reliable diagnostic marker of decompensation. However, in preserved EF heart failure, the plasma levels are significantly lower and a worsening in levels after treatment is not predictive of mortality.

Comparison of fluoroscopic coronary angiography and multi-slice coronary angiography in the characterization of anomalous coronary artery.

Anomalous coronary arteries with an inter-arterial course are associated with sudden cardiac death. We reported a study comparing the accuracy of fluoroscopic coronary angiography (FCA) with that of multi-slice computed tomography (MSCT) coronary angiography in determining the proximal course of anomalous coronary arteries. Twelve patients with thirteen anomalous coronary arteries had both FCA and MSCT coronary angiography were included in this study. Twelve cardiologists individually reviewed FCAs of anomalous coronary arteries and determined the proximal course of anomalous coronary arteries as retro-aortic, inter-arterial or ante-pulmonary. Their diagnoses were compared with MSCT coronary angiography which was regarded as the reference standard in this study. On MSCT coronary angiography, there were six anomalous left circumflex arteries with a retro-aortic course, five anomalous right coronary arteries and one anomalous left anterior descending artery with inter-arterial courses, and a single anomalous left main artery with an ante-pulmonary course. The percentage of correct diagnosis made by 12 cardiologists based on FCA findings was 93/156 or 60%. None of the cardiologists was correct in determining the proximal course of all anomalous coronary arteries. The median number of anomalous coronary arteries with their proximal courses correctly identified by the cardiologists was 7.5 (range 3-12). In conclusion, FCA was limited in delineating the proximal course of anomalous coronary arteries in comparison with MSCT coronary angiography.

CT coronary angiography predicts the outcome of percutaneous coronary intervention of chronic total occlusion.

BACKGROUND: The success rate of percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) is relatively low. Further evaluation of CTO lesion with CT coronary angiography (CT-CA) may help to better select patients that would benefit from percutaneous revascularization. We aimed to test the possible association between failed PCI and transluminal calcification of CTO as assessed by CT-CA. METHODS: Patients with CTO awaiting PCI were scanned with a 16-slice CT. A cardiologist and a radiologist assessed transluminal calcification of CTO lesions on CT images while an interventional cardiologist at a core laboratory assessed conventional variables of invasive fluoroscopic coronary angiography (FCA) associated with failed PCI of CTO. The significance of CT and FCA variables in association with failed PCI were analyzed. RESULTS: In a cohort of 39 patients with 43 CTO lesions, 24 lesions were successfully revascularized. Transluminal calcification > or =50% as assessed on CT-CA was strongly associated with failed PCI (odds ratio [OR] of PCI success = 0.10, 95% confidence interval [CI]: 0.02-0.47, P = 0.003). Blunt stump as seen on FCA was also associated with failed PCI (OR of PCI success = 0.24, 95% CI: 0.07-0.86, P = 0.029). There was no significant evidence to support that the duration of CTO, presence of side branch and bridging collaterals, and the absence of microchannels as assessed with FCA were associated with failed PCI. On multivariate analysis, transluminal calcification > or =50% on CT-CA was the only significant predictor of failed PCI. CONCLUSIONS: Heavy transluminal calcification as assessed with CT-CA is an independent predictor of failed PCI of CTO. CT-CA may have a role in the work-up of CTO patients prior to PCI.

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. METHODS: The present prospective observational study was undertaken in a university teaching hospital between November 2004 and December 2005. Participants were a convenience sample of patients admitted to hospital for investigation of chest pain with TIMI risk scores <3. Consenting patients underwent CT-CA within 48 h of presentation. Outcomes of interest were practicality (proportion of diagnostic quality scans obtained and preparation time for CT-CA), rate of serious adverse events, and accuracy at the patient level using selective coronary angiography as the reference standard. RESULTS: Thirty-four patients were recruited. Diagnostic quality scans were obtained in 26/34 or 76% of patients (four failed CT-CA and four non-diagnostic scans). The median CT preparation time was 1.9 h (range 0.17-4.0). No serious adverse events were found. Fourteen of those 26 patients with diagnostic CT-CA subsequently had selective coronary angiography, of which nine were positive. The sensitivity and specificity of CT-CA in identifying patients with significant coronary artery disease were 9/9 (100%; 95% confidence interval 72-100%) and 4/5 (80%; 95% confidence interval 28-100%), respectively. CONCLUSIONS: The majority of acute chest pain patients with low TIMI risk scores were successfully scanned with a 16-slice CT to produce CT-CA studies with good diagnostic quality and accuracy. No major adverse events were found. The place of CT-CA in diagnostic workup for chest pain remains to be defined.