Cost-effectiveness of population screening for aortic stenosis.

BACKGROUND AND AIMS: Aortic stenosis (AS) is a progressive disease predominantly affecting elderly patients that carries significant morbidity and mortality without aortic valve replacement, the only proven treatment. Our objective was to determine the cost-effectiveness of AS screening using transthoracic echocardiography (TTE) in a geriatric population from the perspective of the publicly funded healthcare system in Canada. METHODS: Markov models estimating the cost-effectiveness ratio (ICER) for AS screening with a one-time TTE were developed. The model included diagnosed and undiagnosed AS health states, hospitalizations, TAVR and post-TAVR health states. Primary analysis included screening at 70 and 80 years of age with intervention at symptom onset, with scenario analysis included for early intervention at the time of severe asymptomatic AS diagnosis. Monte Carlo simulation of 5000 replications was completed with a lifetime horizon and 1.5% discount for costs and outcomes. RESULTS: Screening for AS at the age of 70 years was associated with an ICER of $156,722 and screening at 80 years of age was associated with an ICER of $28,005, suggesting that screening at 80 years of age is cost-effective when willingness-to-pay per QALY is $50,000. Scenario analysis with early intervention was not cost-effective with an ICER of $142,157 at 70 years, and $124,651 at 80 years. CONCLUSION: Screening for AS at 80 years of age with a one-time TTE, in a Canadian population, improves quality of life and is cost-effective in a publicly funded healthcare system providing TAVR is reserved for symptomatic patients.

Diagnostic accuracy of point-of-care ultrasound with artificial intelligence-assisted assessment of left ventricular ejection fraction.

Focused cardiac ultrasound (FoCUS) is becoming standard practice in a wide spectrum of clinical settings. There is limited data evaluating the real-world use of FoCUS with artificial intelligence (AI). Our objective was to determine the accuracy of FoCUS AI-assisted left ventricular ejection fraction (LVEF) assessment and compare its accuracy between novice and experienced users. In this prospective, multicentre study, participants requiring a transthoracic echocardiogram (TTE) were recruited to have a FoCUS done by a novice or experienced user. The AI-assisted device calculated LVEF at the bedside, which was subsequently compared to TTE. 449 participants were enrolled with 424 studies included in the final analysis. The overall intraclass coefficient was 0.904, and 0.921 in the novice (n = 208) and 0.845 in the experienced (n = 216) cohorts. There was a significant bias of 0.73% towards TTE (p = 0.005) with a level of agreement of 11.2%. Categorical grading of LVEF severity had excellent agreement to TTE (weighted kappa = 0.83). The area under the curve (AUC) was 0.98 for identifying an abnormal LVEF (<50%) with a sensitivity of 92.8%, specificity of 92.3%, negative predictive value (NPV) of 0.97 and a positive predictive value (PPV) of 0.83. In identifying severe dysfunction (<30%) the AUC was 0.99 with a sensitivity of 78.1%, specificity of 98.0%, NPV of 0.98 and PPV of 0.76. Here we report that FoCUS AI-assisted LVEF assessments provide highly reproducible LVEF estimations in comparison to formal TTE. This finding was consistent among senior and novice echocardiographers suggesting applicability in a variety of clinical settings.

Contrast-free optical coherence tomography:Systematic evaluation of non-contrast media for intravascular assessment.

BACKGROUND: Coronary revascularization using imaging guidance is rapidly becoming the standard of care. Intravascular optical coherence tomography uses near-infrared light to obtain high resolution intravascular images. Standard optical coherence tomography imaging technique employs iodinated contrast dye to achieve the required blood clearance during acquisition. We sought to systematically evaluate the technical performance of saline as an alternative to iodinated contrast for intravascular optical coherence tomography assessment. METHODS AND RESULTS: We performed bench top optical coherence tomography analysis on nylon tubing with sequential contrast/saline dilutions to empirically derive adjustment coefficients. We then applied these coefficients in vivo in an established rabbit abdominal stenting model with both saline and contrast optical coherence tomography imaging. In this model, we assessed the impact of saline on both quantitative and qualitative vessel assessment. Nylon tubing assessment demonstrated a linear relationship between saline and contrast for both area and diameter. We then derived adjustment coefficients, allowing for accurate calculation of area and diameter when converting saline into both contrast and reference dimensions. In vivo studies confirmed reduced area with saline versus contrast [7.43 (5.67-8.36) mm2 versus 8.2 (6.34-9.39) mm2, p = 0.001] and diameter [3.08 mm versus 3.23 mm, p = 0.001]. Following correction, a strong relationship was achieved in vivo between saline and contrast in both area and diameter without compromising image quality, artefact, or strut assessment. CONCLUSION: Saline generates reduced dimensions compared to contrast during intravascular optical coherence tomography imaging. The relationship across physiologic coronary diameters is linear and can be corrected with high fidelity. Saline does not adversely impact image quality, artefact, or strut assessment.

Long-term mortality and costs following use of Impella® for mechanical circulatory support: a population-based cohort study.

PURPOSE: The Impella® device is a form of mechanical circulatory support (MCS) used in critically ill adults with cardiogenic shock. We sought to evaluate short- and long-term outcomes following the use of Impella, including mortality, healthcare utilization, and costs. METHODS: Population-based, retrospective cohort study of adult patients (≥ 16 yr) receiving Impella in Ontario, Canada (1 April 2012-31March 2019). We captured outcomes through linkage to health administrative databases. The primary outcome was mortality during hospitalization. Secondary outcomes included mortality at 30 days, 90 days, and one year following Impella insertion. We analyzed health system costs in Canadian dollars in the year following the date of the index admission, including the costs of inpatient admission. RESULTS: We included 162 patients. Mean (standard deviation) age was 59.2 (14.5) yr, and 73.5% of patients were male. Median [interquartile range (IQR)] time to Impella insertion from date of hospital admission was 2 [1-9] days. In-hospital mortality was 56.8%, and a significant proportion of patients were bridged to a ventricular assist device (67.9%). Mortality at one year was 61.7%. Among hospital survivors, only 38.6% were discharged home independently. Median [IQR] total cost in the year following admission among all patients was $88,397 [32,718-225,628], of which $66,529 [22,789-183,165] was attributed to inpatient care. CONCLUSIONS: In-hospital mortality among patients with cardiogenic shock receiving Impella is high, but with minimal increase at one year. While Impella patients accrued substantial costs, these largely reflected inpatient costs, and not costs incurred following hospital discharge.

RéSUMé: OBJECTIF: Le dispositif Impella® est un système d'assistance circulatoire mécanique utilisé chez les adultes en état critique souffrant d'un choc cardiogénique. Nous avons souhaité évaluer les issues à court et à long terme liées à l'utilisation de l'Impella, notamment la mortalité, l'utilisation des soins de santé et les coûts. MéTHODE: Nous avons réalisé une étude de cohorte rétrospective basée sur une population de patients adultes (≥ 16 ans) recevant un Impella en Ontario, au Canada (1er avril 2012­31 mars 2019). Nous avons saisi les données pertinentes à nos critères d'évaluation en créant des liens avec les bases de données administratives de santé. Le critère d'évaluation principal était la mortalité pendant l'hospitalisation. Les critères d'évaluation secondaires comportaient la mortalité à 30 jours, 90 jours et un an après l'insertion de l'Impella. Nous avons analysé les coûts pour le système de santé en dollars canadiens au cours de l'année suivant la date d'admission initiale, notamment les coûts hospitaliers. RéSULTATS: Nous avons inclus 162 patients. L'âge moyen (écart type) était de 59,2 (14,5) ans, et 73,5 % des patients étaient des hommes. Le temps médian [écart interquartile (ÉIQ)] jusqu'à insertion de l'Impella depuis l'admission à l'hôpital était de 2 [1­9] jours. La mortalité hospitalière était de 56,8 %, et un dispositif d'assistance ventriculaire a été implanté chez une importante proportion de patients (67,9 %). La mortalité à un an était de 61,7 %. Parmi les survivants hospitaliers, seuls 38,6 % ont reçu leur congé pour un retour indépendant à la maison. Le coût total médian [ÉIQ] pour l'année suivant l'admission parmi tous les patients était de 88 397 $ [32 718 ­ 225 628 $], dont 66 259 $ [22 789 ­ 183 165 $] étaient attribuables aux soins hospitaliers. CONCLUSION: La mortalité hospitalière parmi les patients en choc cardiogénique chez lesquels un Impella est installé est élevée, mais on n'observe qu'une augmentation minimale à un an. Alors que les patients ayant reçu un Impella ont engendré des coûts importants, ces coûts reflètent principalement les coûts hospitaliers et non les coûts encourus après le congé de l'hôpital.

A Shifting Paradigm: The Role of Focused Cardiac Ultrasound in Bedside Patient Assessment.

Transthoracic echocardiography is the standard of care in anatomic and functional cardiovascular assessment; however, focused cardiac ultrasound (FoCUS) performed with portable ultrasound equipment is increasingly being used as an adjunct to comprehensive history and physical examination. FoCUS assessments, unlike formal echocardiography, are intended to assist physicians in answering explicit clinical questions with a narrow differential diagnosis in real time. Over the past decade, a growing body of literature has repeatedly shown the value that FoCUS adds to clinical evaluation. Specifically, FoCUS improves point-of-care diagnostic accuracy, which in turn modifies treatment plans, decreases time to diagnosis, and reduces resource utilization. Although less robust, there is also evidence showing improvement in clinical outcomes. Based on this evidence, clinicians, training programs, and clinical societies have embraced FoCUS as a tool to complement bedside patient evaluation. Herein, we review the evidence for FoCUS in clinical practice, specifically evaluating the diagnostic accuracy, the impact on clinical decision-making, and the effect on clinical outcomes.

Evaluation of an in vitro coronary stent thrombosis model for preclinical assessment.

Stent thrombosis remains an infrequent but significant complication following percutaneous coronary intervention. Preclinical models to rapidly screen and validate therapeutic compounds for efficacy are lacking. Herein, we describe a reproducible, high throughput and cost-effective method to evaluate candidate therapeutics and devices for either treatment or propensity to develop stent thrombosis in an in vitro bench-top model. Increasing degree of stent malapposition (0.00 mm, 0.10 mm, 0.25 mm and 0.50 mm) was associated with increasing thrombosis and luminal area occlusion (4.1 ± 0.5%, 6.3 ± 0.5%, 19.7 ± 4.5%, and 92.6 ± 7.4%, p < 0.0001, respectively). Differences in stent design in the form of bare-metal, drug-eluting, and bioresorbable vascular scaffolds demonstrated differences in stent thrombus burden (14.7 ± 3.8% vs. 20.5 ± 3.1% vs. 86.8 ± 5.3%, p < 0.01, respectively). Finally, thrombus burden was significantly reduced when healthy blood samples were incubated with Heparin, ASA/Ticagrelor (DAPT), and Heparin+DAPT compared to control (DMSO) at 4.1 ± 0.6%, 6.9 ± 1.7%, 4.5 ± 1.2%, and 12.1 ± 1.8%, respectively (p < 0.01). The reported model produces high throughput reproducible thrombosis results across a spectrum of antithrombotic agents, stent design, and degrees of apposition. Importantly, performance recapitulates clinical observations of antiplatelet/antithrombotic regimens as well as device and deployment characteristics. Accordingly, this model may serve as a screening tool for candidate therapies in preclinical evaluation.

The Next Generation of Physician-Scientists: Adapting to Academic Cardiology in the 21st Century.

More than 3 decades ago, Wyngaarden and Gill first warned of the challenges facing physician-scientists in their seminal papers "The Clinical Investigator as an Endangered Species" and "The End of the Physician-Scientist." In the years since these papers were published, there has been expansion of stage I-II preclinical research focusing on discovery and exploratory studies. Expansion has often come at the expense of physician-scientists whose traditional role has been to bridge the gap between early preclinical research (stage I-II) and clinical trials (stage IV). Consequently, a paradigm shift has occurred, and increasing pressure has been placed on physician-scientists to choose between clinical practice and fundamental research. This shift is particularly concerning in the field of cardiovascular medicine, where the ubiquitous nature and clinical significance of cardiovascular disease make the role of the translational scientist essential. The challenges facing academic cardiologists have then further been amplified by the necessity not only to maintain clinical competence but also to maintain competence in highly technical fields with rapidly advancing technology. Potential solutions to these problems include increasing support from postgraduate training programs, increased participation of trainees in physician-scientist development programs, and recognition of the pivotal role physician-scientists play in translational research by funding agencies. Although the physician-scientist remains an endangered species, multifaceted solutions with a focus on collaboration among institutions, training programs, and funding agencies have the potential to maximize efficiency in biomedical research and successfully translate scientific discoveries from bench to bedside.

Photoplethysmography using a smartphone application for assessment of ulnar artery patency: a randomized clinical trial.

BACKGROUND: Radial artery access is commonly performed for coronary angiography and invasive hemodynamic monitoring. Despite limitations in diagnostic accuracy, the modified Allen test (manual occlusion of radial and ulnar arteries followed by release of the latter and assessment of palmar blush) is used routinely to evaluate the collateral circulation to the hand and, therefore, to determine patient eligibility for radial artery access. We sought to evaluate whether a smartphone application may provide a superior alternative to the modified Allen test. METHODS: We compared the modified Allen test with a smartphone heart rate-monitoring application (photoplethysmography readings detected using a smartphone camera lens placed on the patient's index finger) in patients undergoing a planned cardiac catheterization. Test order was randomly assigned in a 1:1 fashion. All patients then underwent conventional plethysmography of the index finger, followed by Doppler ultrasonography of the radial and ulnar arteries (the diagnostic standard). The primary outcome was diagnostic accuracy of the heart rate-monitoring application. RESULTS: Among 438 patients who were included in the study, we found that the heart rate-monitoring application had a superior diagnostic accuracy compared with the modified Allen test (91.8% v. 81.7%, p = 0.002), attributable to its greater specificity (93.0% v. 82.8%, p = 0.001). We also found that this application had greater diagnostic accuracy for assessment of radial or ulnar artery patency in the ipsilateral and contralateral wrist (94.0% v. 84.0%, p < 0.001). INTERPRETATION: A smartphone application used at the bedside was diagnostically superior to traditional physical examination for confirming ulnar patency before radial artery access. This study highlights the potential for smartphone-based diagnostics to aid in clinical decision-making at the patient's bedside. Trial registration: Clinicaltrials.gov, no. NCT02519491.

Safety and Efficacy of a Pharmacoinvasive Strategy in ST-Segment Elevation Myocardial Infarction: A Patient Population Study Comparing a Pharmacoinvasive Strategy With a Primary Percutaneous Coronary Intervention Strategy Within a Regional System.

OBJECTIVES: This study investigated the safety and efficacy of a pharmacoinvasive strategy compared with a primary percutaneous coronary intervention (PCI) strategy for ST-segment elevation myocardial infarction (STEMI) in the context of a real-world system. BACKGROUND: Primary PCI continues to be the optimal reperfusion therapy; however, in areas where PCI centers are not readily available, a pharmacoinvasive strategy has been proposed. METHODS: The University of Ottawa Heart Institute regional STEMI system provides a primary PCI strategy for patients presenting within a 90-km radius from the PCI center, and a pharmacoinvasive strategy for patients outside this limit. We included all confirmed STEMI patients between April 2009 and May 2011. The primary efficacy outcome was a composite of mortality, reinfarction, or stroke and the primary safety outcome was major bleeding. RESULTS: We identified 236 and 980 consecutive patients enrolled in pharmacoinvasive and primary PCI strategies, respectively. The median door-to-needle time was 31 min in the pharmacoinvasive group and the median door-to-balloon time was 95 min in the primary PCI group. In a multivariable model, there was no significant difference in the primary efficacy outcome (odds ratio: 1.54; p = 0.21); however, the propensity for more bleeding with a pharmacoinvasive strategy approached statistical significance (odds ratio: 2.02; p = 0.08). CONCLUSIONS: Within the context of a STEMI system, a pharmacoinvasive strategy was associated with similar rates of the composite of mortality, reinfarction, or stroke as compared with a primary PCI strategy; however, there was a propensity for more bleeding with a pharmacoinvasive strategy.

The Rapid Assessment of Competency in Echocardiography Scale: Validation of a Tool for Point-of-Care Ultrasound.

OBJECTIVES: Increased use of point-of-care ultrasound (US) requires the development of assessment tools that measure the competency of learners. In this study, we developed and tested a tool to assess the quality of point-of-care cardiac US studies performed by novices. METHODS: In phase 1, the Rapid Assessment of Competency in Echocardiography (RACE) scale was developed on the basis of structured interviews with subject matter experts; the tool was then piloted on a small series of US studies in phase 2. In phase 3, the tool was applied to a sample of 154 point-of-care US studies performed by 12 learners; each study was independently rated by 2 experts, with quantitative analysis subsequently performed. RESULTS: Evidence of the content validity of the RACE scale was supported by a consensus exercise, wherein experts agreed on the assessment dimensions and specific items that made up the RACE scale. The tool showed good inter-rater reliability. An analysis of inter-item correlations provided support for the internal structure of the scale, and the tool was able to discriminate between learners early in their point-of-care US learning and those who were more advanced in their training. CONCLUSIONS: The RACE scale provides a straightforward means to assess learner performance with minimal requirements for evaluator training. Our results support the conclusion that the tool is an effective means of making valid judgments regarding competency in point-of-care cardiac US.

Bivalirudin for primary percutaneous coronary interventions: outcome assessment in the Ottawa STEMI registry.

BACKGROUND: Data from randomized trials has demonstrated the superiority of bivalirudin to glycoprotein IIb/IIIa inhibitors plus heparin in patients undergoing primary percutaneous coronary intervention. Real-world performance of bivalirudin in primary percutaneous coronary intervention and the benefit of bivalirudin over heparin remain unknown in an era of routine dual antiplatelet therapy. METHODS AND RESULTS: From July 2004 to December 2010, 2317 consecutive patients were indexed in the University of Ottawa Heart Institute ST-segment-elevation myocardial infarction registry. During this period 748 patients received bivalirudin, 699 patients received glycoprotein IIb/IIIa inhibitors, and 676 patients received unfractionated heparin alone. The primary outcome was the rate of noncoronary artery bypass graft related thrombolysis in myocardial infarction major bleeding. Bivalirudin significantly reduced the primary outcome compared with heparin plus glycoprotein IIb/IIIa inhibitors (2.7% versus 7.3%, adjusted OR 2.96, 95% CI: 1.61-5.45, P<0.001) and the composite end point of death, stroke, reinfarction and major bleed (OR 1.66, 95% CI: 1.12-2.45, P=0.01). Compared with heparin alone, a reduction in major bleeds (OR 1.21, 95% CI: 0.60-2.44, P=0.59) or the composite end point (1.05, 95% CI: 0.68-1.63, P=0.83) with bivalirudin could not be demonstrated. Notably, major bleeding was associated with a 5-fold increase in the risk of mortality both in-hospital (3.5% versus 20.6%) and out to 180 days (5.6% versus 25.8%). CONCLUSIONS: Bivalirudin use compared with glycoprotein IIb/IIIa inhibitors plus heparin as an antithrombotic strategy in primary percutaneous coronary intervention results in less major bleeding in contemporary practice. A benefit of bivalirudin over heparin could not be established with this registry and requires additional investigations to either confirm or refute.