Search

Introduction: Sleep deprivation impacts clinical performance. However, literature is conflicting, with insufficient focus on patient outcomes. The aim of this study was to assess if patient satisfaction and prescription errors in outpatient clinics were adversely affected when consulting post-call versus non-post-call registrars. Methods: This prospective, quantitative study was set in a large teaching hospital in Singapore. Between November 2015 and February 2016, patients from clinics run by a registrar after 24-hour shift were recruited to post-call group. Patients from non-post-call clinics run by the same registrar were controls. Outcome measures were patient satisfaction, using 5-item 4-point Likert scale questionnaire, and prescribing error rate, defined as number of errors over number of orders. Differences were analysed using chi-squared test. Results: 103 of 106 (97%) patients in 9 post-call clinics and 93 of 105 (90%) patients in 9 non-post-call clinics were recruited. Questionnaire completion rate was 99%. 536 and 526 prescriptions were ordered in post-call and non-post-call groups, respectively. Percentage of top-box responses (greatest satisfaction) was higher in post-call group overall (79.3% versus 62.4%, p

Abstract Background Stress cardiovascular magnetic resonance (CMR) offers assessment of ventricular function, myocardial perfusion and viability in a single examination to detect coronary artery disease (CAD). We developed an in-scanner exercise stress CMR (ExCMR) protocol using supine cycle ergometer and aimed to examine the diagnostic value of a multiparametric approach in patients with suspected CAD, compared with invasive fractional flow reserve (FFR) as the reference gold standard. Methods In this single-centre prospective study, patients who had symptoms of angina and at least one cardiovascular disease risk factor underwent both ExCMR and invasive angiography with FFR. Rest-based left ventricular function (ejection fraction, regional wall motion abnormalities), tissue characteristics and exercise stress-derived (perfusion defects, inducible regional wall motion abnormalities and peak exercise cardiac index percentile-rank) CMR parameters were evaluated in the study. Results In the 60 recruited patients with intermediate CAD risk, 50% had haemodynamically significant CAD based on FFR. Of all the CMR parameters assessed, the late gadolinium enhancement, stress-inducible regional wall motion abnormalities, perfusion defects and peak exercise cardiac index percentile-rank were independently associated with FFR-positive CAD. Indeed, this multiparametric approach offered the highest incremental diagnostic value compared to a clinical risk model (χ 2 for the diagnosis of FFR-positive increased from 7.6 to 55.9; P

The aim of this study was to evaluate a new analytical method for calculating non-invasive fractional flow reserve (FFRAM) to diagnose ischemic coronary lesions. Patients with suspected or known coronary artery disease (CAD) who underwent computed tomography coronary angiography (CTCA) and invasive coronary angiography (ICA) with FFR measurements from two sites were prospectively recruited. Obstructive CAD was defined as diameter stenosis (DS) ≥50% on CTCA or ICA. FFRAM was derived from CTCA images and anatomical features using analytical method and was compared with computational fluid dynamics (CFD)-based FFR (FFRB) and invasive ICA-based FFR. FFRAM, FFRB, and invasive FFR ≤ 0.80 defined ischemia. A total of 108 participants (mean age 60, range: 30–83 years, 75% men) with 169 stenosed coronary arteries were analyzed. The per-vessel accuracy, sensitivity, specificity, and positive predictive and negative predictive values were, respectively, 81, 75, 86, 81, and 82% for FFRAM and 87, 88, 86, 83, and 90% for FFRB. The area under the receiver operating characteristics curve for FFRAM (0.89 and 0.87) and FFRB (0.90 and 0.86) were higher than both CTCA- and ICA-derived DS (all p < 0.0001) on per-vessel and per-patient bases for discriminating ischemic lesions. The computational time for FFRAM was much shorter than FFRB (2.2 ± 0.9 min vs. 48 ± 36 min, excluding image acquisition and segmentation). FFRAM calculated from a novel and expeditious non-CFD approach possesses a comparable diagnostic performance to CFD-derived FFRB, with a significantly shorter computational time.

Invasive fractional flow reserve (FFR) is recommended to guide stent deployment. We previously introduced a non-invasive FFR calculation (FFRB) based on computed tomography coronary angiography (CTCA) with reduced-order computational fluid dynamics (CFD) and resistance boundary conditions. Current study aimed to assess the feasibility and accuracy of FFRB for predicting coronary hemodynamics before and after stenting, with invasive FFR as the reference. Twenty-five patients who had undergone CTCA were prospectively enrolled before invasive coronary angiography (ICA) and FFR-guided percutaneous coronary intervention (PCI) on 30 coronary vessels. Using reduced-order CFD with novel boundary conditions on three-dimensional (3D) patient-specific anatomic models reconstructed from CTCA, we calculated FFRB before and after virtual stenting. The latter simulated PCI by clipping stenotic segments from the 3D coronary models and replacing them with segments to mimic the deployed coronary stents. Pre- and post-virtual stenting FFRB were compared with FFR measured pre- and post-PCI by investigators blinded to FFRB results. Among 30 coronary lesions, pre-stenting FFRB (mean 0.69 ± 0.12) and FFR (mean 0.67 ± 0.13) exhibited good correlation (r = 0.86, p < 0.001) and agreement [mean difference 0.024, 95% limits of agreement (LoA): −0.11, 0.15]. Similarly, post-stenting FFRB (mean 0.84 ± 0.10) and FFR (mean 0.86 ± 0.08) exhibited fair correlation (r = 0.50, p < 0.001) and good agreement (mean difference 0.024, 95% LoA: −0.20, 0.16). The accuracy of FFRB for identifying post-stenting ischemic lesions (FFR ≤ 0.8) (residual ischemia) was 87% (sensitivity 80%, specificity 88%). Our novel FFRB, based on CTCA with reduced-order CFD and resistance boundary conditions, accurately predicts the hemodynamic effects of stenting which may serve as a tool in PCI planning.

Proper inlet boundary conditions are essential for accurate computational fluid dynamics (CFD) modeling. We developed methodology to derive noninvasive FFRB using CFD and computed tomography coronary angiography (CTCA) images. This study aims to assess the influence of brachial mean blood pressure (MBP) and total coronary inflow on FFRB computation. Twenty-two patients underwent both CTCA and FFR measurements. Total coronary flow was computed from left ventricular mass (LVM) measured from CTCA. A total of 286 CFD simulations were run by varying MBP and LVM at 70, 80, 90, 100, 110, 120, and 130% of the measured values. FFRB increased with incrementally higher input values of MBP: 0.78 ± 0.12, 0.80 ± 0.11, 0.82 ± 0.10, 0.84 ± 0.09, 0.85 ± 0.08, 0.86 ± 0.08, and 0.87 ± 0.07, respectively. Conversely, FFRB decreased with incrementally higher inputs value of LVM: 0.86 ± 0.08, 0.85 ± 0.08, 0.84 ± 0.09, 0.84 ± 0.09, 0.83 ± 0.10, 0.83 ± 0.10, and 0.82 ± 0.10, respectively. Noninvasive FFRB calculated using measured MBP and LVM on a total of 30 vessels was 0.84 ± 0.09 and correlated well with invasive FFR (0.83 ± 0.09) (r = 0.92, P < 0.001). Positive association was observed between FFRB and MBP input values (mmHg) and negative association between FFRB and LVM values (g). Respective slopes were 0.0016 and −0.005, respectively, suggesting potential application of FFRB in a clinical setting. Inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions. NEW & NOTEWORTHY While brachial mean blood pressure (MBP) and left ventricular mass (LVM) measured from CTCA are the two CFD simulation input parameters, their effects on noninvasive fractional flow reserve (FFRB) have not been systematically investigated. We demonstrate that inaccurate MBP and LVM inputs differing from patient-specific values could result in misclassification of borderline ischemic lesions. This is important in the clinical application of noninvasive FFR in coronary artery disease diagnosis. [ABSTRACT FROM AUTHOR]

Background: Resident attrition is costly but literature studying the motivations behind it in obstetrics and gynaecology (OBGYN) is lacking. Objectives: We aimed to study the relationship between prior specialty-appropriate work experience and risk of attrition amongst OBGYN residents in Singapore, and identify factors placing residents at greater risk of attrition. Methods: This nationwide mixed methods case control study studied all OBGYN residents in Singapore for the 2011 and 2012 intakes. A pre-piloted questionnaire was used to identify work experience and risk factors related to resident attrition. Structured interviews were conducted with a subgroup of participants chosen for diversity of educational background, work experience, and position towards residency. Results: 28 of 33 (84.8%) eligible residents participated in this study. Female (40.9% vs. 0%), married (50.0% vs. 22.2%) and Singaporean (38.1% vs.14.3%) residents more often considered attrition from training. Those accepted into residency after graduation were 33% less likely to have considered leaving. No statistical difference was observed between residents with prior work experience and those without (38.9% vs. 20.0%, p=0.417). All interviewees believed that prior experience informs expectations and eases initial learning. Low job satisfaction related to mismatched expectations was the most quoted reason for considering attrition. 85.7% of interviewed residents were concerned about competing work and family demands. Conclusions: Lack of specialty-appropriate work experience contributes to misinformed training expectations and increased attrition risk. Residents who have considered attrition may still desire career longevity in their specialty. Reduction in mismatched expectations promises to improve job satisfaction and translate to career longevity. [ABSTRACT FROM AUTHOR]

Aims: Near-infrared spectroscopy (NIRS) has been employed to assess the composition of the atherosclerotic plaques in native coronary arteries. However, little is known about the detection of neoatherosclerosis by NIRS in in-stent restenosis (ISR). The aim of the study was to assess the relationship between the distribution of lipid determined by NIRS and morphology of ISR on optical coherence tomography (OCT). Methods and results: We performed both NIRS and OCT in 39 drug-eluting stents with ISR. Values of lipid-core burden index (LCBI) derived by NIRS were compared with the OCT-derived thickness of the fibrous cap covering neoatherosclerotic lesions. A total of 22 (49%) in-stent neointimas were identified as lipid rich by both NIRS and OCT. There was good agreement between OCT and NIRS in identifying lipid within in-stent neointima (kappa = 0.60, 95% CI: 0.34-0.86). OCT identified thin-cap neoatheromas (TCNA) (<65 µm) in 12 stents (23%). The minimal cap thickness of in-stent neoatherosclerotic plaque measured by OCT correlated with the maxLCBI4mm (maximal LCBI per 4 mm) within the stent (r = -0.77, P< 0.01). Moreover, maxLCBI4mm was able to accurately predict TCNA with a cut-off value of >144. Conclusion: NIRS correlates with OCT identification of lipids in stented vessels and is able to predict the presence of thin fibrous cap neoatheroma. [ABSTRACT FROM AUTHOR]