[Application of photoplethysmography for atrial fibrillation in early warning, diagnosis and integrated management].

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Early diagnosis and effective management are important to reduce atrial fibrillation-related adverse events. Photoplethysmography (PPG) is often used to assist wearables for continuous electrocardiograph monitoring, which shows its unique value. The development of PPG has provided an innovative solution to AF management. Serial studies of mobile health technology for improving screening and optimized integrated care in atrial fibrillation have explored the application of PPG in screening, diagnosing, early warning, and integrated management in patients with AF. This review summarizes the latest progress of PPG analysis based on artificial intelligence technology and mobile health in AF field in recent years, as well as the limitations of current research and the focus of future research.

Diagnostic validation of smart wearable device embedded with single-lead electrocardiogram for arrhythmia detection.

Objective: To validate a single-lead electrocardiogram algorithm for identifying atrial fibrillation, atrial premature beats, ventricular premature beats, and sinus rhythm. Methods: A total of 656 subjects aged 19 to 94 years were enrolled. Participants were simultaneously tested with a wristwatch (Huawei Watch GT2 Pro, Huawei Technologies Co., Ltd, Shenzhen, China) and a 12-lead electrocardiogram for 3 minutes. A total of 1926 electrocardiogram signals from 628 subjects (282 men and 346 women) aged 19 to 94 years (median 64 years) were analyzed using an algorithm. Results: The numbers of subjects with atrial fibrillation, atrial premature beats, ventricular premature beats, and sinus rhythm were 129, 141, 107, and 251, respectively, and together they had a total of 1926 electrocardiogram signals. For the three-class classification system, the recall, precision, and F1 score were 97.6%, 96.5%, 97.0% for sinus rhythm; 96.7%, 96.9%, 96.8% for atrial fibrillation; and 92.8%, 94.2%, 93.5% for ectopic beats, respectively. The macro-F1 score of the three-class classification system was 95.8%. For the four-class classification system, the recall, precision, and F1 score were 97.6%, 96.5%, 97.0% for sinus rhythm; 96.7%, 96.9%, 96.8% for atrial fibrillation; 90.5%, 89.4%, 89.9% for atrial premature beats; and 86.1%, 89.6%, 87.8% for ventricular premature beats, respectively. The macro-F1 score of the four-class classification system was 92.9%. Conclusions: The single-lead electrocardiogram algorithm embedded into smart wearables demonstrated good performance in detecting atrial fibrillation, atrial/ventricular premature beats, and sinus rhythm, and thus would facilitate atrial fibrillation screening and management.

Structured Rehabilitation for Patients with Atrial Fibrillation Based on an Integrated Care Approach: Protocol for a Prospective, Observational Cohort Study.

Background: Guideline-recommended integrated care based on the ABC (Atrial fibrillation Better Care) pathway for "general" patients with atrial fibrillation (AF) improves clinical outcomes, as demonstrated in our prior mobile Atrial Fibrillation Application (mAFA)-II cluster randomized trial. The present study aims to investigate whether mAFA III-supported structured follow-up rehabilitation packages adapted to patient risk profiles and different treatment patterns (eg, for patients receiving drug treatment only, AF ablation, or left atrial appendage occlusion [LAAO]) will improve guideline adherence and reduce the risk of adverse cardiovascular events. Methods and Analysis: In this prospective, observational mAFA III pilot cohort study, patients with AF aged ≥ 18 years will be enrolled using the mAFA III App for self-management. Assuming an annual rate of composite outcome of "ischaemic stroke or systemic embolism, all-cause death and cardiovascular hospitalization" of 29.3% for non-ABC pathway compliance compared with 20.8% for ABC pathway compliance, at least 1475 patients would be needed to detect the outcome of the A, B and C components of the ABC pathway, assuming a withdrawal rate of 20% in the first year. The primary endpoint is adherence to guidelines regarding the A, B and C components of the ABC pathway. Ancillary analyses will be performed to determine the impact of the ABC pathway using smart technologies on the outcomes among the "high-risk" population (eg, ≥75 years old, with multimorbidities, with polypharmacy) and the application of artificial intelligence machine-learning AF risk prediction management in assessing AF recurrence. The individualised anticoagulants with AF burden will be monitored by smart devices. Trial Registration Number: ISRCTN13724416.

Natural Language Processing in a Clinical Decision Support System for the Identification of Venous Thromboembolism: Algorithm Development and Validation.

BACKGROUND: It remains unknown whether capturing data from electronic health records (EHRs) using natural language processing (NLP) can improve venous thromboembolism (VTE) detection in different clinical settings. OBJECTIVE: The aim of this study was to validate the NLP algorithm in a clinical decision support system for VTE risk assessment and integrated care (DeVTEcare) to identify VTEs from EHRs. METHODS: All inpatients aged ≥18 years in the Sixth Medical Center of the Chinese People's Liberation Army General Hospital from January 1 to December 31, 2021, were included as the validation cohort. The sensitivity, specificity, positive and negative likelihood ratios (LR+ and LR-, respectively), area under the receiver operating characteristic curve (AUC), and F1-scores along with their 95% CIs were used to analyze the performance of the NLP tool, with manual review of medical records as the reference standard for detecting deep vein thrombosis (DVT) and pulmonary embolism (PE). The primary end point was the performance of the NLP approach embedded into the EHR for VTE identification. The secondary end points were the performances to identify VTE among different hospital departments with different VTE risks. Subgroup analyses were performed among age, sex, and the study season. RESULTS: Among 30,152 patients (median age 56 [IQR 41-67] years; 14,247/30,152, 47.3% females), the prevalence of VTE, PE, and DVT was 2.1% (626/30,152), 0.6% (177/30,152), and 1.8% (532/30,152), respectively. The sensitivity, specificity, LR+, LR-, AUC, and F1-score of NLP-facilitated VTE detection were 89.9% (95% CI 87.3%-92.2%), 99.8% (95% CI 99.8%-99.9%), 483 (95% CI 370-629), 0.10 (95% CI 0.08-0.13), 0.95 (95% CI 0.94-0.96), and 0.90 (95% CI 0.90-0.91), respectively. Among departments of surgery, internal medicine, and intensive care units, the highest specificity (100% vs 99.7% vs 98.8%, respectively), LR+ (3202 vs 321 vs 77, respectively), and F1-score (0.95 vs 0.89 vs 0.92, respectively) were in the surgery department (all P<.001). Among low, intermediate, and high VTE risks in hospital departments, the low-risk department had the highest AUC (1.00 vs 0.94 vs 0.96, respectively) and F1-score (0.97 vs 0.90 vs 0.90, respectively) as well as the lowest LR- (0.00 vs 0.13 vs 0.08, respectively) (DeLong test for AUC; all P<.001). Subgroup analysis of the age, sex, and season demonstrated consistently good performance of VTE detection with >87% sensitivity and specificity and >89% AUC and F1-score. The NLP algorithm performed better among patients aged ≤65 years than among those aged >65 years (F1-score 0.93 vs 0.89, respectively; P<.001). CONCLUSIONS: The NLP algorithm in our DeVTEcare identified VTE well across different clinical settings, especially in patients in surgery units, departments with low-risk VTE, and patients aged ≤65 years. This algorithm can help to inform accurate in-hospital VTE rates and enhance risk-classified VTE integrated care in future research.

Conductive single-wall carbon nanotubes/extracellular matrix hybrid hydrogels promote the lineage-specific development of seeding cells for tissue repair through reconstructing an integrin-dependent niche.

BACKGROUND: The niche of tissue development in vivo involves the growth matrix, biophysical cues and cell-cell interactions. Although natural extracellular matrixes may provide good supporting for seeding cells in vitro, it is evitable to destroy biophysical cues during decellularization. Reconstructing the bioactivities of extracellular matrix-based scaffolds is essential for their usage in tissue repair. RESULTS: In the study, a hybrid hydrogel was developed by incorporating single-wall carbon nanotubes (SWCNTs) into heart-derived extracellular matrixes. Interestingly, insoluble SWCNTs were well dispersed in hybrid hydrogel solution via the interaction with extracellular matrix proteins. Importantly, an augmented integrin-dependent niche was reconstructed in the hybrid hydrogel, which could work like biophysical cues to activate integrin-related pathway of seeding cells. As supporting scaffolds in vitro, the hybrid hydrogels were observed to significantly promote seeding cell adhesion, differentiation, as well as structural and functional development towards mature cardiac tissues. As injectable carrier scaffolds in vivo, the hybrid hydrogels were then used to delivery stem cells for myocardial repair in rats. Similarly, significantly enhanced cardiac differentiation and maturation(12.5 ± 2.3% VS 32.8 ± 5%) of stem cells were detected in vivo, resulting in improved myocardial regeneration and repair. CONCLUSIONS: The study represented a simple and powerful approach for exploring bioactive scaffold to promote stem cell-based tissue repair.

Association of serum uric acid with mortality and cardiovascular outcomes in patients with hypertension: a meta-analysis.

Studies on the association of uric acid with mortality and cardiovascular outcomes in patients with hypertension have produced contradictory results. The objective of this meta-analysis was to evaluate the prognostic utility of uric acid in hypertensive patients. We comprehensively searched PubMed and Embase databases (until July 31, 2020) to identify eligible studies that reported the association of uric acid with mortality and cardiovascular outcomes in hypertensive patients. Outcome measures included cardiovascular or all-cause mortality, coronary artery disease (CAD), stroke, and major adverse cardiovascular events (MACEs). Eleven eligible studies of 49,800 hypertensive patients were identified. For patients with the highest than those with reference lower group of uric acid level, the pooled hazard ratio (HR) was 1.51 (95% confidence interval [CI] 1.12-2.02) for all-cause mortality, 1.68 (95% CI 1.28-2.20) for cardiovascular mortality, 1.31 (95% CI 1.10-1.55) for CAD, and 1.48 (95% CI 1.28-1.70) for MACEs. However, there was no significant association between elevated uric acid level and incident stroke in hypertensive patients. This meta-analysis indicates that elevated uric acid level is significantly associated with an increased risk of cardiovascular or all-cause mortality, CAD and MACEs in hypertensive patients. Hypertensive patients with highest uric acid level exhibited a tendency for reduced risk of stroke, but the difference is not significant.

Association Between Metabolic Syndrome and All-Cause Mortality in Patients with Acute Coronary Syndrome: A Meta-Analysis.

The association between metabolic syndrome (MetS) and survival outcome after acute coronary syndrome (ACS) remains controversial. This meta-analysis sought to examine the association of MetS with all-cause mortality among patients with ACS. Two authors independently searched PubMed and Embase databases (from their inception to June 27, 2020) for studies that examined the association of MetS with all-cause mortality among patients with ACS. Outcome measures were in-hospital mortality and all-cause mortality during the follow-up. A total of 10 studies involving 49 896 ACS patients were identified. Meta-analysis indicated that presence of MetS was associated with an increased risk of long-term all-cause mortality [risk ratio (RR) 1.25; 95% CI 1.15-1.36; n=9 studies] and in-hospital mortality (RR 2.35; 95% CI 1.40-3.95; n=2 studies), respectively. Sensitivity and subgroup analysis demonstrated the credibility of the value of MetS in predicting long-term all-cause mortality. MetS is associated with an increased risk of long-term all-cause mortality among patients with ACS. However, additional studies are required to investigate the association of MetS with in-hospital mortality.

Effects of carbon nanotube-mediated Caspase3 gene silencing on cardiomyocyte apoptosis and cardiac function during early acute myocardial infarction.

RNA interference (RNAi) technology can achieve efficient and specific silencing of Caspase3 gene expression, thus providing new options for anti-apoptosis treatment. However, delivering siRNA to specific cells and tissues in the body is a significant challenge. Therefore, we aim to construct a functionalized single-walled carbon nanotube (F-CNT) bound to siRNA from Caspase3. The obtained gene transfer carrier F-CNT-siCas3 not only demonstrated a good water solubility and biocompatibility, but also had a high transfection efficiency of up to 82%, which significantly downregulated the expression level of the Caspase3 gene miRNA and protein in primary cardiomyocytes. Furthermore, it was verified by in vivo experiments that Caspase3 gene silencing had obvious protective effects on myocardial cell apoptosis, ventricular remodeling, and cardiac function in Sprague-Dawley (SD) rats after coronary artery ligation. This study may provide an important theoretical basis for the application of F-CNT in vivo siRNA gene therapy to treat cardiovascular diseases.

Comparison of diagnostic accuracy of dual-axis rotational versus standard coronary angiography.

The data about the accuracy of dual-axis rotational coronary angiography (DARCA) in detecting coronary artery disease (CAD) is scare. This study aimed to compare the diagnostic accuracy of DARCA versus standard coronary angiography (SA). 70 patients with possible CAD underwent SA following by DARCA were prospectively enrolled. The primary endpoint was the non-inferiority comparison of the two modalities regarding diagnosis of CAD. Coronary lesion assessment, quantitative coronary angiography (QCA) analysis, and screening adequacy comparisons were performed. All images were analyzed by two independent reviewers except QCA analysis that was analyzed by the third independent reviewer. Radiation dose, contrast usage and procedural time were recorded. This trial is registered with ClinicalTrials.gov, Number NCT01776866. 63 of 70 patients were analyzed. DARCA was non-inferior to SA regarding the diagnosis of CAD (reviewer one-positive agreement: 100%, negative agreement: 100%, p = 1; p = 0.003 for non-inferiority; reviewer two-positive agreement: 96%, negative agreement: 95%, p = 1; p = 0.016 for non-inferiority). All reviewers showed good agreement between the two modalities for the diagnosis of CAD, coronary lesion assessment, QCA analysis, and screening adequacy, as reflected by kappa coefficients between 0.61 and 1.00. DARCA was associated with 41% reduction in radiation dose, 30% in contrast usage and 29% in procedure time (all p < 0.001). DARCA is clinically comparable to SA concerning the diagnostic accuracy for CAD, while markedly reduces radiation dose, contrast usage and procedure time.

Combining ECM Hydrogels of Cardiac Bioactivity with Stem Cells of High Cardiomyogenic Potential for Myocardial Repair.

Tissue engineering exploring the combination of scaffolds and seeding cells was proposed as a promising strategy for myocardial repair. However, the therapeutic outcomes varied greatly due to different selection of scaffolds and seeding cells. Herein, the potential of combining bioactive extracellular matrix (ECM) hydrogels and high cardiomyogenic seeding cells was explored for myocardial repair in vitro and in vivo. Temperature-sensitive ECM hydrogels were prepared from decellularized rat hearts, and cardiomyogenic seeding cells were isolated from brown adipose (brown adipose-derived stem cells (BADSCs)). The in vitro studies demonstrated that ECM hydrogel significantly supported the proliferation and cardiomyogenic differentiation of BADSCs. Importantly, the function and maturation of BADSC-derived cardiomyocytes were also promoted as evidenced by Ca2+ transient's measurement and protein marker expression. After myocardial transplantation, the combination of BADSCs and ECM hydrogels significantly preserved cardiac function and chamber geometry compared with BADSCs or ECM hydrogels alone. Meanwhile, the ECM hydrogel also enhanced BADSC engraftment and myocardial regeneration in vivo. These results indicated that heart-derived ECM hydrogels exerted significant influence on the fate of cardiomyogenic cells toward benefiting myocardial repair, which may explain the enhanced stem cell therapy by the scaffold. Collectively, it indicated that the combination of ECM hydrogel and the cardiomyogenic cells may represent a promising strategy for cardiac tissue engineering.

Antiplatelet Effect of Different Loading Doses of Ticagrelor in Patients With Non-ST-Elevation Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: The APELOT Trial.

BACKGROUND: We hypothesized that a high ticagrelor loading dose (LD) may improve platelet inhibition in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI). METHODS: This interventional multicentre open-label trial randomized 278 patients with NSTE-ACS to a high (360 mg) or conventional (180 mg) ticagrelor LD. The primary outcome was the platelet reactivity index (PRI) 1 hour after administration of the LD. Secondary outcomes included PRI at 0.5 hour, 1 hour, 8 hours, and 24 hours; periprocedural myocardial infarction (PMI); major cardiac adverse events; and bleeding events. RESULTS: Two hundred sixty-two patients completed the major end points. PRI was lower in the high-LD group than in the conventional-LD group at any time point (all, P < 0.05), including at 1 hour (12.2% vs 16.7%; P = 0.023). At 0.5 hour, the high-LD group showed a lower high-platelet reactivity rate (49.6% vs 60.2%; P = 0.013) and a higher low-platelet reactivity rate (24.8% vs 12.8%; P = 0.017) than did the conventional LD group. No significant differences in the bleeding rates were found between the 2 groups (14% vs 14.3%). Four cases of PMI and 1 death in each group, as well as 1 acute myocardial infarction in the conventional LD group, occurred. There was no stroke, target lesion revascularization, or target vessel revascularization. CONCLUSIONS: Doubling the ticagrelor LD achieved faster onset and greater platelet inhibition without an increase in adverse events in patients with NSTE-ACS undergoing PCI.

Five-year outcomes of ST-elevation myocardial infarction versus non-ST-elevation acute coronary syndrome treated with biodegradable polymer-coated sirolimus-eluting stents: Insights from the CREATE trial.

BACKGROUND: Long-term outcome of drug-eluting stents (DES) for ST-elevation myocardial infarction (STEMI) versus non-ST-elevation acute coronary syndrome (NSTE-ACS) remains unclear. This study sought to compare the long-term outcomes of biodegradable polymer-coated DES in patients with STEMI versus NSTE-ACS. METHODS: We explored a post hoc analysis of the 5-year outcome of the CREATE trial in the subgroup of patients with STEMI (n=318) versus NSTE-ACS (n=1223) who were implanted with biodegradable polymer-coated DES. The primary outcome was the rate of major adverse cardiac events (MACE) at 5 years. Clopidogrel and aspirin for 6 months followed by chronic aspirin therapy were recommended. RESULTS: STEMI patients showed a trend of increase in MACE (8.7% vs. 6.8%, log rank p=0.289) compared to NSTE-ACS patients at 5 years, and a greater risk of cardiac death (5.4% vs. 2.1%, log rank p=0.003), mainly driven by the higher cardiac death rate within the first month after stent placement (log rank p=0.003) and the last year of follow-up (log rank p=0.001). No significant difference in stent thrombosis was found between them (3.1% vs. 2.5%, log rank p=0.653). Prolonged clopidogrel therapy (>6 months) showed no effect on risk of MACE or stent thrombosis between the two groups (both p for interaction >0.1). CONCLUSIONS: STEMI patients have a higher risk of cardiac mortality compared with NSTE-ACS patients after biodegradable polymer-coated DES placement, primarily attribute to more cardiac deaths that happened within the first month after the event and the last year of follow-up.

Correlation between dual-axis rotational coronary angiography and intravascular ultrasound in a coronary lesion assessment.

The purpose of this study was to evaluate the accuracy of dual-axis rotational coronary angiography (DARCA) for coronary lesion assessment by directly comparing with intravascular ultrasound (IVUS). From October 2014 to December 2015, 40 patients (58 lesions) who had undergone both DARCA and IVUS were included in the image analysis. The minimum lumen diameter (MLD), lesion length, reference vessel diameter (RVD) and percent diameter stenosis at the same lesion, were identified and assessed. Significant correlation with IVUS was found for DARCA in either lesion length (r = 0.90, P < 0.001) or RVD (r = 0.81, P < 0.001) comparison. DARCA had fair correlation with IVUS for both MLD (r = 0.65, P < 0.001) and diameter stenosis (r = 0.48, P < 0.001). From the Bland-Altman plots, there was a good agreement between DARCA and IVUS regarding MLD (mean difference: -0.23 mm, 95 % limits of agreement: -0.96 to 0.50 mm) and RVD (mean difference: -0.15 mm, 95 % limits of agreement: -0.85 to 0.55 mm), while lesser agreement was found on lesion length (mean difference: -3.39 mm, 95 % limits of agreement: -12.63 to 5.85 mm) and diameter stenosis (mean difference: 4.82 %, 95 % limits of agreement: -17.05 to 26.68 %). There is an adequate correlation and agreement between DARCA and IVUS in coronary lesion assessment.

Design and Rationale of the APELOT Trial: A Randomized, Open-Label, Multicenter, Phase IV Study to Evaluate the Antiplatelet Effect of Different Loading Dose of Ticagrelor in Patients With Non-ST Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention.

Ticagrelor is a direct acting on the P2Y12 receptor blocker, which provides faster and greater platelet inhibition than clopidogrel. However, several studies suggested that in ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention (PCI), ticagrelor exhibits initial delay in the onset of antiplatelet action. Unlike ST-segment elevation myocardial infarction, in non-ST-segment elevation acute coronary syndrome (NSTE-ACS), management pathways are highly variable, and some patients may require surgery. Effect of higher loading dose (LD) of ticagrelor in patients with NSTE-ACS in providing faster and stronger inhibition of platelet aggregation is unknown and needs to be explored further.The AntiPlatelet Effect of different Loading dOse of Ticagrelor trial is an interventional, randomized, open-label, multicenter, phase IV trial designed to evaluate whether a high LD (360 mg) of ticagrelor compared with the conventional LD (180 mg) will result in a higher inhibition of platelet aggregation without increasing bleeding events in NSTE-ACS participants undergoing PCI.A total of 250 NSTE-ACS participants will be randomized to receive a ticagrelor LD (360 or 180 mg), followed by a maintenance dose of 90 mg twice a day (bid) starting 12 hours after the LD. The primary endpoint is platelet reactivity index measured by vasodilator-stimulated phosphoprotein phosphorylation 2 hours after the LD, and the secondary endpoints include occurrence of periprocedural myocardial infarction and bleeding events.The AntiPlatelet Effect of different Loading dOse of Ticagrelor trial will provide important information on the risks and benefits of a high LD (360 mg) of ticagrelor in achieving a faster and stronger platelet inhibition compared with the conventional LD (180 mg) in NSTE-ACS patients undergoing PCI.

Stent boost subtract imaging for the assessment of optimal stent deployment in coronary ostial lesion intervention: comparison with intravascular ultrasound.

Percutaneous coronary intervention (PCI) of ostial lesions is complex and is technically very demanding. Intravascular ultrasound (IVUS) is considered the gold standard method to guide PCI but has several limitations. Stent boost subtract (SBS) imaging is an enhancement of the radiologic edge of the stent by digital management of regular X-ray images. The purpose of this study was to determine the availability of stent enhancement with SBS during ostial PCI by comparison with IVUS.We investigated SBS and IVUS after stent implantation in 58 ostial lesions in 55 patients. SBS and IVUS were performed in all patients to obtain improved stent location and to detect optimal release and deployment. We defined the SBS and IVUS criteria for accuracy of stent location and adequate stent deployment. IVUS findings showed that stent location was generally good. The location was accurate in 48 (82.8%) and inadequate stent deployment was observed in 10 of 58 (17.2%). Eight SBS images showed inadequate stent expansion. SBS predicted inadequate findings of IVUS with 100% specificity and 80% sensitivity, while a significant positive correlation was observed between SBS-MSA and MSA by IVUS with a regression coefficient of 0.95.Imaging techniques have a primary role during ostial PCI. SBS is a simple and quick method that offers several advantages, enabling improved stent location, adequate stent expansion, and optimal apposition of the struts to the wall. SBS imaging could be conventionally used during ostial PCI, especially in centers where IVUS is not used routinely.

Dual-axis rotational coronary angiography can reduce peak skin dose and scattered dose: a phantom study.

The purpose of this study was to evaluate peak skin dose received by the patient and scattered dose to the operator during dual-axis rotational coronary angiography (DARCA), and to compare with those of standard coronary angiography (SA). An anthropomorphic phantom was used to simulate a patient undergoing diagnostic coronary angiography. Cine imaging was applied on the phantom for 2 s, 3 s, and 5 s in SA projections to mimic clinical situations with normal vessels, and uncomplicated and complicated coronary lesions. DARCA was performed in two curved trajectories around the phantom. During both SA and DARCA, peak skin dose was measured with thermoluminescent dosimeter arrays and scattered dose with a dosimeter at predefined height (approximately at the level of left eye) at the operator's location. Compared to SA, DARCA was found lower in both peak skin dose (range: 44%-82%, p < 0.001) and scattered dose (range: 40%-70%, p < 0.001). The maximal reductions were observed in the set mimicking complicated lesion examinations (82% reduction for peak skin dose, p < 0.001; 70% reduction for scattered dose, p < 0.001). DARCA reduces both peak skin dose and scattered dose in comparison to SA. The benefi t of radiation dose reduction could be especially signifi cant in complicated lesion examinations due to large reduction in X-ray exposure time. The use of DARCA could, therefore, be recommended in clinical practice to minimize radiation dose.

Comparison of radiation dose to operator between transradial and transfemoral coronary angiography with optimised radiation protection: a phantom study.

A growing concern in applying radial access in cardiac catheterisation is the increased operator radiation exposure. This study used an anthropomorphic phantom to simulate transradial and transfemoral coronary angiography with optimised radiation protection conditions. Operator radiation exposure was measured with thermoluminescent dosemeters at predefined locations. Compared with the femoral route, the radial route was associated with a dose decrease of 15 % at the operator's chest level with optimised radiation shielding. However, radiation exposure to the operator's hand remained significantly higher when applying radial access even with collective protective equipment used (by a factor of 2). Furthermore, the efficiency of operator radiation protection was found to be dependent on the tube incidence. Awareness should be raised about the significant increase of radiation exposure to operators' hands in transradial coronary angiography. Protection to reduce the dose level to the hands is necessary and should be further improved.

Impact of StentBoost subtract imaging on patient radiation exposure during percutaneous coronary intervention.

The purpose of this study was to assess the impact of StentBoost Subtract (SBS) imaging on patient radiation dose during percutaneous coronary intervention. Data were prospectively collected between February 2010 and November 2012 at a tertiary cardiac catheterization. All patients who had scheduled for coronary stent implantation performed by one expert interventional cardiologist with sufficient experience in SBS imaging and radiation protection, were included. The patients were divided into groups with or without SBS. A multiple linear regression analysis was used to determine the impact of SBS imaging on patient radiation dose. Of 712 patients screened, 414 patients were enrolled in the study (with SBS: n = 177, without SBS: n = 237). Although the DAP, fluoroscopy time and cine frames used in the group with SBS were significantly increased when compared with those used in the group without SBS (P < 0.05), multiple linear regression shows SBS imaging has no significant impact on patient radiation dose (P > 0.05). Multivariate predictors of patient radiation dose were the patients' BMI, B2/C lesions, number of stents placed and bifurcation stenting (P < 0.05). In selected patients, SBS imaging can be performed with comparable patient radiation dose, compared with plain fluoroscopic imaging. This may attribute to the operator's sufficient experience in SBS imaging and radiation protection.

Randomized study on the safety and efficacy of dual-axis rotational versus standard coronary angiography in.

BACKGROUND: Dual-axis rotational coronary angiography (DARCA) was developed as an innovative adaptation of rotational angiography (RA), but it requires a longer coronary injection compared to standard coronary angiography (SA). As the body of the average Chinese patient is smaller than that of most western patients, with the same contrast injection time, the risk of complications from the contrast agent is increased in this population. The purpose of this study was to assess the clinical safety and efficacy of DARCA in the diagnosis of coronary artery disease (CAD) in the Chinese population by directly comparing it to SA. METHODS: Two hundred Chinese patients were randomized to either the SA group (n = 100) or DARCA group (n = 100). Contrast utilization, radiation exposure and procedure time were recorded for each modalities. Blood pressure (BP), heart rate (HR) pre and post injection symptoms and any arrhythmias were recorded. RESULTS: Compared to the SA group, there was a 42% reduction in contrast utilization, 55% reduction in radiation exposure and a 31% shorter procedure time in the DARCA group. In both groups, there were slight declines in the systolic BP values in the left coronary artery (LCA) post injection (P < 0.01). Moreover, post injection HRs for the LCA were also reduced in the DARCA group (P < 0.01). But all of these changes were small, transient and without clinical importance. Only one patient (1%) in the DARCA group had an attack of ventricular tachycardia immediately post injection and it resolved by itself during LCA angiography. No arrhythmias occurred in the SA group. CONCLUSION: DARCA is a safe, efficient, and clinically comparable alternative to SA in the diagnosis of coronary artery disease in the Chinese population with less contrast utilized, which is less radiation exposure and a shorter procedure time than SA.