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Aims Coronary flow reserve (CFR) assessment has proven clinical utility, but Doppler-based methods are sensitive to noise and operator bias, limiting their clinical applicability. The objective of the study is to expand the adoption of invasive Doppler CFR, through the development of artificial intelligence (AI) algorithms to automatically quantify coronary Doppler quality and track flow velocity. Methods and results A neural network was trained on images extracted from coronary Doppler flow recordings to score signal quality and derive values for coronary flow velocity and CFR. The outputs were independently validated against expert consensus. Artificial intelligence successfully quantified Doppler signal quality, with high agreement with expert consensus (Spearman’s rho: 0.94), and within individual experts. Artificial intelligence automatically tracked flow velocity with superior numerical agreement against experts, when compared with the current console algorithm [AI flow vs. expert flow bias −1.68 cm/s, 95% confidence interval (CI) −2.13 to −1.23 cm/s, P < 0.001 with limits of agreement (LOA) −4.03 to 0.68 cm/s; console flow vs. expert flow bias −2.63 cm/s, 95% CI −3.74 to −1.52, P < 0.001, 95% LOA −8.45 to −3.19 cm/s]. Artificial intelligence yielded more precise CFR values [median absolute difference (MAD) against expert CFR: 4.0% for AI and 7.4% for console]. Artificial intelligence tracked lower-quality Doppler signals with lower variability (MAD against expert CFR 8.3% for AI and 16.7% for console). Conclusion An AI-based system, trained by experts and independently validated, could assign a quality score to Doppler traces and derive coronary flow velocity and CFR. By making Doppler CFR more automated, precise, and operator-independent, AI could expand the clinical applicability of coronary microvascular assessment.

There have been no studies comparing clinical outcomes of physiology-guided revascularization in patients with unprotected left main coronary disease (ULMD) between percutaneous coronary intervention (PCI) vs. coronary artery bypass grafting (CABG). The aim of this study was to assess the long-term clinical outcomes between PCI and CABG of patients with physiologically significant ULMD. From an international multicenter registry of ULMD patients interrogated with instantaneous wave-free ratio (iFR), we analyzed data from 151 patients (85 PCI vs. 66 CABG) who underwent revascularization according to the cutoff value of iFR ≤ 0.89. Propensity score matching was employed to adjust for baseline clinical characteristics. The primary endpoint was a composite of all-cause death, non-fatal myocardial infarction, and ischemia-driven target lesion revascularization. The secondary endpoints were the individual components of the primary endpoint. Mean age was 66.6 (± 9.2) years, 79.2% male. Mean SYNTAX score was 22.6 (± 8.4) and median iFR was 0.83 (IQR 0.74–0.87). After performing propensity score matching analysis, 48 patients treated with CABG were matched to those who underwent PCI. At a median follow-up period of 2.8 years, the primary endpoint occurred in 8.3% in PCI group and 20.8% in CABG group, respectively (HR 3.80; 95% CI 1.04–13.9; p = 0.043). There was no difference in each component of the primary event (p > 0.05 for all). Within the present study, iFR-guided PCI was associated with lower cardiovascular events rate in patients with ULMD and intermediate SYNTAX score, as compared to CABG. Graphical abstract State-of-the-art PCI vs. CABG for ULMD. Study design and primary endpoint in patients with physiologically significant ULMD. MACE was defined as the composite of all-cause death, non-fatal myocardial infarction, and target lesion revascularization. The blue line denotes the PCI arm, and the red line denotes the CABG arm. PCI was associated with significantly lower risk of MACE than CABG. CABG: coronary artery bypass grafting; iFR: instantaneous wave-free ratio; MACE: major adverse cardiovascular events; PCI: percutaneous coronary intervention; ULMD: unprotected left main coronary artery disease.

AimsAdditional randomized clinical trial (RCT) data comparing transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) is available, including longer term follow-up. A meta-analysis comparing TAVI to SAVR was performed. A pragmatic risk classification was applied, partitioning lower-risk and higher-risk patients.Methods and resultsThe main endpoints were death, strokes, and the composite of death or disabling stroke, occurring at 1 year (early) or after 1 year (later). A random-effects meta-analysis was performed. Eight RCTs with 8698 patients were included. In lower-risk patients, at 1 year, the risk of death was lower after TAVI compared with SAVR [relative risk (RR) 0.67; 95% confidence interval (CI) 0.47 to 0.96, P = 0.031], as was death or disabling stroke (RR 0.68; 95% CI 0.50 to 0.92, P = 0.014). There were no differences in strokes. After 1 year, in lower-risk patients, there were no significant differences in all main outcomes. In higher-risk patients, there were no significant differences in main outcomes. New-onset atrial fibrillation, major bleeding, and acute kidney injury occurred less after TAVI; new pacemakers, vascular complications, and paravalvular leak occurred more after TAVI.ConclusionIn lower-risk patients, there was an early mortality reduction with TAVI, but no differences after later follow-up. There was also an early reduction in the composite of death or disabling stroke, with no difference at later follow-up. There were no significant differences for higher-risk patients. Informed therapy decisions may be more dependent on the temporality of events or secondary endpoints than the long-term occurrence of main clinical outcomes.

Despite the now routine integration of invasive physiologic systems into coronary catheter laboratories worldwide, it remains critical that all operators maintain a sound understanding of the fundamental physiologic basis for coronary pressure assessment. More specifically, performing operators should be well informed regarding the basis for hyperemic (ie, fractional flow reserve) and nonhyperemic (ie, instantaneous wave-free ratio and other nonhyperemic pressure ratio) coronary pressure assessment. In this article, we provide readers a comprehensive history charting the inception, development, and validation of hyperemic and nonhyperemic coronary pressure assessment.

Objectives: This study developed a neural network to perform automated pressure waveform analysis and allow real-time accurate identification of damping. Background: Damping of aortic pressure during coronary angiography must be identified to avoid serious complications and make accurate coronary physiology measurements. There are currently no automated methods to do this, and so identification of damping requires constant monitoring, which is prone to human error. Methods: The neural network was trained and tested versus core laboratory expert opinions derived from 2 separate datasets. A total of 5,709 aortic pressure waveforms of individual heart beats were extracted and classified. The study developed a recurrent convolutional neural network to classify beats as either normal, showing damping, or artifactual. Accuracies were reported using the opinions of 2 independent core laboratories. Results: The neural network was 99.4% accurate (95% confidence interval: 98.8% to 99.6%) at classifying beats from the testing dataset when judged against the opinions of the internal core laboratory. It was 98.7% accurate (95% confidence interval: 98.0% to 99.2%) when judged against the opinions of an external core laboratory not involved in neural network training. The neural network was 100% sensitive, with no beats classified as damped misclassified, with a specificity of 99.8%. The positive predictive and negative predictive values were 98.1% and 99.5%. The 2 core laboratories agreed more closely with the neural network than with each other. Conclusions: Arterial waveform analysis using neural networks allows rapid and accurate identification of damping. This demonstrates how machine learning can assist with patient safety and the quality control of procedures.

Objectives The aim of this study was to assess the long-term clinical outcomes of patients with left main coronary artery (LM) stenosis in whom treatment strategy was based on the instantaneous wave-free ratio (iFR). Background The overall safety of iFR to guide revascularization decision making in patients with stable coronary artery disease has been established. However, no study has examined the safety of deferral of revascularization of LM disease on the basis of iFR. Methods This multicenter observational study included 314 patients in whom LM stenosis was deferred (n = 163 [51.9%]) or revascularized (n = 151 [48.1%]) according to the iFR cutoff ≤0.89. The primary endpoint was a composite of all-cause death, nonfatal myocardial infarction, and ischemia-driven target lesion revascularization. The secondary endpoints were each individual component of the primary endpoint and also cardiac death. Results At a median follow-up period of 30 months, the primary endpoint occurred in 15 patients (9.2%) in the deferred group and 22 patients (14.6%) in the revascularized group (hazard ratio: 1.45; 95% confidence interval: 0.75 to 2.81; p = 0.26), indicating no evidence of a significant difference between the 2 groups. For the secondary endpoints, findings in the iFR-based deferral and revascularization groups were as follows: all-cause death, 3.7% versus 4.6%; cardiac death, 1.2% versus 2.0%; nonfatal myocardial infarction, 2.5% versus 5.3%; and target lesion revascularization, 4.3% versus 5.3% (p > 0.05 for all). Conclusions Deferral of revascularization of LM stenosis on the basis of iFR appears to be safe, with similar long-term outcomes to those in patients in whom LM revascularization was performed according to iFR values.

This study developed a neural network to perform automated pressure waveform analysis and allow real-time accurate identification of damping.Damping of aortic pressure during coronary angiography must be identified to avoid serious complications and make accurate coronary physiology measurements. There are currently no automated methods to do this, and so identification of damping requires constant monitoring, which is prone to human error.The neural network was trained and tested versus core laboratory expert opinions derived from 2 separate datasets. A total of 5,709 aortic pressure waveforms of individual heart beats were extracted and classified. The study developed a recurrent convolutional neural network to classify beats as either normal, showing damping, or artifactual. Accuracies were reported using the opinions of 2 independent core laboratories.The neural network was 99.4% accurate (95% confidence interval: 98.8% to 99.6%) at classifying beats from the testing dataset when judged against the opinions of the internal core laboratory. It was 98.7% accurate (95% confidence interval: 98.0% to 99.2%) when judged against the opinions of an external core laboratory not involved in neural network training. The neural network was 100% sensitive, with no beats classified as damped misclassified, with a specificity of 99.8%. The positive predictive and negative predictive values were 98.1% and 99.5%. The 2 core laboratories agreed more closely with the neural network than with each other.Arterial waveform analysis using neural networks allows rapid and accurate identification of damping. This demonstrates how machine learning can assist with patient safety and the quality control of procedures.

Background Patients presenting with ST-elevation myocardial infarction commonly have multi-vessel coronary artery disease. After the culprit artery is treated, the optimal treatment strategy for the residual disease is not yet defined. Large observational studies suggest that treatment of residual disease should be deferred but smaller randomised controlled trials (RCTs) suggest multi-vessel primary percutaneous coronary intervention (MV-PPCI) at the time of STEMI is safe. We examine if allocation bias of high-risk patients could explain the conflicting results between observational studies and RCTs and aim to resolve the paradox between the two. Methods A meta-analysis of registries comparing culprit-only PPCI to MV-PPCI was performed. We then determined if high-risk patients were more likely to be allocated to MV-PPCI. A meta-regression was performed to determine if any allocation bias of high-risk patients could explain the difference in outcomes between therapies. Results 47,717 patients (19 studies) were eligible. MV-PPCI had higher mortality than culprit-only PPCI (OR 1.59, 95% CI 1.12 to 2.24, p=0.03). However, higher risk patients were more likely to be allocated to MV-PPCI (OR 1.45, 95% CI 1.18 to 1.78, p=0.0005). When this was accounted for, there was no difference in mortality between culprit-only PPCI and MV-PPCI (OR 0.99, 95% CI 0.69 to 1.41, p=0.94). Discussion Clinicians preferentially allocate higher-risk patients to MV-PPCI at the time of STEMI, resulting in observational studies reporting higher mortality with this strategy. When this is accounted for, these large observational studies in ‘real world' patients support the conclusion of the smaller RCTs in the field: MV-PPCI has equivalent mortality to a culprit-only approach.

This paper reports the development, validation, and public availability of a new neural network-based system which attempts to identify the manufacturer and even the model group of a pacemaker or defibrillator from a chest radiograph.Medical staff often need to determine the model of a pacemaker or defibrillator (cardiac rhythm device) quickly and accurately. Current approaches involve comparing a device's radiographic appearance with a manual flow chart.In this study, radiographic images of 1,676 devices, comprising 45 models from 5 manufacturers were extracted. A convolutional neural network was developed to classify the images, using a training set of 1,451 images. The testing set contained an additional 225 images consisting of 5 examples of each model. The network's ability to identify the manufacturer of a device was compared with that of cardiologists, using a published flowchart.The neural network was 99.6% (95% confidence interval [CI]: 97.5% to 100.0%) accurate in identifying the manufacturer of a device from a radiograph and 96.4% (95% CI: 93.1% to 98.5%) accurate in identifying the model group. Among 5 cardiologists who used the flowchart, median identification of manufacturer accuracy was 72.0% (range 62.2% to 88.9%), and model group identification was not possible. The network's ability to identify the manufacturer of the devices was significantly superior to that of all the cardiologists (p 0.0001 compared with the median human identification; p 0.0001 compared with the best human identification).A neural network can accurately identify the manufacturer and even model group of a cardiac rhythm device from a radiograph and exceeds human performance. This system may speed up the diagnosis and treatment of patients with cardiac rhythm devices, and it is publicly accessible online.

BACKGROUND: Recently, the therapeutic benefits of percutaneous coronary intervention (PCI) have been challenged in patients with stable coronary artery disease (SCD). OBJECTIVES: The authors examined the impact of PCI on exercise responses in the coronary circulation, the microcirculation, and systemic hemodynamics in patients with SCD. METHODS: A total of 21 patients (mean age 60.3 ± 8.4 years) with SCD and single-vessel coronary stenosis underwent cardiac catheterization. Pre-PCI, patients exercised on a supine ergometer until rate-limiting angina or exhaustion. Simultaneous trans-stenotic coronary pressure-flow measurements were made throughout exercise. Post-PCI, this process was repeated. Physiological parameters, rate-limiting symptoms, and exercise performance were compared between pre-PCI and post-PCI exercise cycles. RESULTS: PCI reduced ischemia as documented by fractional flow reserve value (pre-PCI 0.59 ± 0.18 to post-PCI 0.91 ± 0.07), instantaneous wave-free ratio value (pre-PCI 0.61 ± 0.27 to post-PCI 0.96 ± 0.05) and coronary flow reserve value (pre-PCI 1.7 ± 0.7 to post-PCI 3.1 ± 1.0; p < 0.001 for all). PCI increased peak-exercise average peak coronary flow velocity (p < 0.0001), coronary perfusion pressure (distal coronary pressure; p < 0.0001), systolic blood pressure (p = 0.01), accelerating wave energy (p < 0.001), and myocardial workload (rate-pressure product; p < 0.01). These changes observed immediately following PCI resulted from the abolition of stenosis resistance (p < 0.0001). PCI was also associated with an immediate improvement in exercise time (+67 s; 95% confidence interval: 31 to 102 s; p

BackgroundThis exploratory study investigates the feasibility for observing and evaluating intraoperative communication practices using simulation techniques. Complex procedures are increasingly performed on patients under local anaesthesia, where patients are fully conscious. Interventional cardiac procedures are one such example where patients have reported high levels of anxiety undergoing procedures. Although communication styles can serve to alleviate patient anxiety during interventions, leading to a better patient experience, there has been little observational research on communication, while patient perspectives in intraoperative contexts have been underexplored.MethodsIn this mixed-methods study, observational analysis was conducted on 20 video-recorded simulated scenarios, featuring physician operators (of varied experience levels), communication and interactions with a simulated patient (trained actor), in a controlled and highly realistic catheter laboratory setting. Two independent raters and the simulated patient embedded in scenarios retrospectively rated physician communication styles and interactions with the patient via four key parameters. Patient perspectives of communication were further explored via a quantitative measure of anxiety and semistructured qualitative interviews.ResultsWhile independent ratings of physician–patient communications demonstrated few discernible differences according to physicians’ experience level, patient ratings were consistently higher for experienced physicians and lower for novice physicians for the four interaction styles. Furthermore, the patient’s anxiety scores were differentiable according to operators’ experience level. Thematic analysis provided further insights into how patient perspectives, including affective dimensions are characterised, and how physician interactions can amplify or attenuate feelings of anxiety through tone of voice, continuity in communication during the procedure, communicating while multitasking and connecting with the patient.ConclusionsOur findings indicate underlying patient assumptions about physicians’ experience levels, intraoperative communication styles and impact on anxiety. While observational methods can be applied to simulated intraoperative clinical contexts, evaluation techniques such as observational rating tools need to incorporate patient perspectives about undergoing conscious surgery.

The authors sought to compare the diagnostic performance of fractional flow reserve (FFR), instantaneous wave-free ratio (iFR), and resting distal coronary artery pressure/aortic pressure (Pd/Pa) usingThe diagnostic performance of invasive physiological indices was reported to be different according to the reference to define the presence of myocardial ischemia.A total of 115 consecutive patients with left anterior descending artery stenosis who underwent bothAll invasive physiological indices correlated with CFR and RFR (all p values 0.001). The overall diagnostic accuracies of FFR, iFR, and resting Pd/Pa were not different for CFR 2.0 (FFR 69.6%, iFR 73.9%, and resting Pd/Pa 70.4%) and RFR 0.75 (FFR 73.9%, iFR 71.3%, and resting Pd/Pa 74.8%). Discrimination and reclassification abilities of invasive physiological indices were comparable for CFR. For RFR, FFR showed better discrimination and reclassification ability than resting indices (IDI = 0.170 and category-free NRI = 0.971 for iFR; IDI = 0.183 and category-free NRI = 1.058 for resting Pd/Pa; all p values 0.001).The diagnostic performance of invasive physiological indices showed no differences in the prediction of myocardial ischemia defined by CFR. Using RFR as a reference, FFR showed a better discrimination and reclassification ability than resting indices.

BackgroundPreparing middle grades students to be successful in the 21st century has long been the goal of the middle school movement. For students to be successful, it is imperative that they receive an education that goes beyond basic instruction in reading, writing, and mathematics to include opportunities for them to use their unique abilities to solve real-world problems, work collaboratively, and deepen their knowledge base in a safe, supportive, and nurturing environment.In recent years, middle schools have been criticized and accused of replacing academic rigor with identity development. In the report Mayhem in the Middle: How Middle Schools have Failed America-and How to Make Them Work, Cheri Pierson Yecke (2005) stated, "Middle schoolism is based on pseudo-scientific theories and downplays academic achievement. The middle school movement advances the notion that academic achievement should take a back seat to such ends as self-exploration, socialization, and group learning" (p. ii). Other organizations and councils with a long history of focusing on middle level education have been proponents of rigorous academic programs for middle level students (i.e., Carnegie Council on Adolescent Development, 1989; Jackson & Davis, 2000; National Forum to Accelerate Middle-Grades Reform, 2006b; National Middle School Association, 2003), while continuing to address the social, emotional, and physical needs of these adolescents. This study acknowledges the middle school movement has both proponents and critics but that both positions seek a relatively similar goal-an excellent educational experience for all middle level students.In an effort to heighten the sense of urgency concerning the need for high-performing middle schools, the National Forum to Accelerate Middle- Grades Reform launched the national Schools to Watch (STW) program to recognize middle level schools that are on a trajectory toward academic excellence, developmental responsiveness, and social equity (National Forum to Accelerate Middle-Grades Reform, 2006b). Since its inception, the National Forum's Schools to Watch program has expanded to include state-level recognition programs. This study explored the relationship between schools recognized as a Kentucky School to Watch (KSTW) and the implementation of the tenets of the middle school concept as outlined in This We Believe (NMSA, 2003), a commonly accepted standard for effective middle level education. Though they are separate entities, the visions for effective middle schools espoused by the National Forum and the National Middle School Association (NMSA) are similar. Because Kentucky's Schools to Watch were evaluated using the criteria established by the National Forum to Accelerate Middle-Grades Reform, using the same criteria to evaluate other schools would be unfairly biased against schools that have not applied for the Kentucky School to Watch designation. To avoid this bias, This We Believe was used as the conceptual framework for this research. Using survey data and data available through the Kentucky Department of Education, the researchers examined Kentucky Schools to Watch from two perspectives and sought to:* Compare the perceived level of middle school implementation between schools designated a Kentucky School to Watch and Kentucky middle schools that have not earned this designation* Compare the levels of academic achievement between schools designated a Kentucky School to Watch and those that have not earned this designation.This study addresses two key research questions outlined by National Middle School Association's A 21st Century Research Agenda (1997): (1) What is the depth and breadth of implementation of middle level education programs, policies, and practices necessary to bring about various levels of change? (2) What are the direct and indirect effects of middle school programs, policies, and practice on student achievement? Having this information helps validate the use of the Schools to Watch criteria as a means of middle school program evaluation and staff development. …

As a result of the pressures of educational reform and high-stakes assessment, some schools run the risk of foregoing active, student-centered learning activities for building test-taking skills and the memorization of discrete facts (Gredler, 1999; Jackson & Davis, 2000). Coupled with the additional pressure to fulfill the expectations of No Child Left Behind (NCLB), educators may feel the need to abandon the tenets of the middle school philosophy for more teacher-centered instructional approaches. Since the enactment of the Kentucky Education Reform Act (KERA) in 1990, schools and teachers have been accountable for the achievement of students and implementation of the state’s assessment standards. Using the responses of 216 educators from 17 middle schools in Northern Kentucky, this descriptive study explores middle grade teachers’ perceptions of how high-stakes testing and state accountability standards influence instructional strategies utilized in the classroom. Results indicate that though teachers acknowledge the importance of including active and student-centered strategies on a consistent basis, the state tests seem to drive the curriculum and warrant more teacher-focused instructional methods—lecture, worksheets, and whole-class discussion. In addition, recommendations are offered to improve instructional practice, enhance middle grades teacher preparation programs, and guide future research.