Variation in use of technology among vascular access specialists: an analysis of the PICC1 survey.

BACKGROUND: While the use of technologies such as ultrasound and electrocardiographic (ECG) guidance systems to place peripherally inserted central catheters (PICCs) has grown, little is known about the clinicians who use these tools or their work settings. METHODS: Using data from a national survey of vascular access specialists, we identified technology users as PICC inserters that: (a) use ultrasound to find a suitable vein for catheter placement; (b) measure catheter-to-vein ratio; and (c) use ECG for PICC placement. Individual and organizational-level characteristics between technology users versus non-users were assessed. Bivariable comparisons were made using Chi-squared or Fisher's exact tests; two-sided alpha with p<0.05 was considered statistically significant. RESULTS: Of the 2762 PICC inserters who accessed the survey, 1518 (55%) provided information regarding technology use. Technology users reported greater experience than non-technology users, with a higher percentage stating they had placed >1000 PICCs (55% vs. 45%, p<0.001). A significantly greater percentage of technology users also reported being certified in vascular access by an external agency than non-technology users (75% vs. 63%, p<0.001). Technology users were more often part of vascular access teams with ≥10 members compared to non-technology users (35% vs. 22%, p<0.001). Some practices also varied between the two groups: for example, use of certain securement devices and dressings differed between technology users and non-users (p<0.001). CONCLUSIONS: Technology use by vascular access clinicians while placing PICCs is associated with clinician characteristics, work setting and practice factors. Understanding whether such differences influence clinical care or patient outcomes appears necessary.

Preventing sudden death of athletes with electrocardiographic screening: what is the absolute benefit and how much will it cost?

OBJECTIVES: This study sought to estimate the costs of a national electrocardiographic (ECG) screening of athletes in the United States and the number of lives that would be saved by that program. BACKGROUND: A single study from Italy suggests that mandatory ECG screening of athletes reduces their risk of sudden cardiac death. Based on that study, ECG screening of athletes is endorsed by the European Society of Cardiology, though not by the American Heart Association. The widespread application of ECG screening remains controversial because the absolute reduction of sudden cardiac death risk provided, and its economic ramifications, have not been studied in detail. METHODS: A cost-projection model was based on the Italian study, replicating its data in terms of athlete characteristics and physician performance. The size of the screening-eligible population was estimated from data provided by the National Collegiate Athletic Association and the National Federation of State High School Associations. The costs of diagnostic tests were obtained from Medicare reimbursement rates. RESULTS: A 20-year program of ECG screening of young competitive athletes in the United States would cost between $51 and $69 billion and could be expected to save 4,813 lives. Accordingly, the cost per life saved is likely to range between $10.6 and $14.4 million. CONCLUSIONS: Our cost-projection model suggests that replicating the Italian strategy of ECG screening in the United States would result in enormous costs per life saved.

Patterns and predictors of stress testing modality after percutaneous coronary stenting: data from the NCDR(®).

OBJECTIVES: We evaluated temporal trends and geographic variation in choice of stress testing modality after percutaneous coronary intervention (PCI), as well as associations between modality and procedure use after testing. BACKGROUND: Stress testing is frequently performed post-PCI, but the choices among available modalities (electrocardiography only, nuclear, or echocardiography; pharmacological or exercise stress) and consequences of such choices are not well characterized. METHODS: CathPCI Registry(®) data were linked with identifiable Medicare claims to capture stress testing use between 60 and 365 days post-PCI and procedures within 90 days after testing. Testing rates and modality used were modeled on the basis of patient, procedure, and PCI facility factors, calendar quarter, and Census Divisions using Poisson and logistic regression. Post-test procedure use was assessed using Gray's test. RESULTS: Among 284,971 patients, the overall stress testing rate after PCI was 53.1 per 100 person-years. Testing rates declined from 59.3 in quarter 1 (2006) to 47.1 in quarter 4 (2008), but the relative use of modalities changed little. Among exercise testing recipients, adjusted proportions receiving electrocardiography-only testing varied from 6.8% to 22.8% across Census Divisions; and among exercise testing recipients having an imaging test, the proportion receiving echocardiography (versus nuclear) varied from 9.4% to 34.1%. Post-test procedure use varied among modalities; exercise electrocardiography-only testing was associated with more subsequent stress testing (13.7% vs. 2.9%; p < 0.001), but less catheterization (7.4% vs. 14.1%; p < 0.001) than imaging-based tests. CONCLUSIONS: Modest reductions in stress testing after PCI occurring between 2006 and 2008 cannot be ascribed to trends in use of any single modality. Additional research should assess whether this trend represents better patient selection for testing or administrative policies (e.g., restricted access for patients with legitimate testing needs). Geographic variation in utilization of stress modalities and differences in downstream procedure use among modalities suggest a need to identify optimal use of the different test modalities in individual patients.

Implantable cardioverter defibrillator algorithms: status review in terms of computational cost.

In recent decades, implantable cardioverter defibrillators (ICDs) have improved substantially, becoming the treatment of choice for patients at high risk of life-threatening arrhythmias. Nevertheless, inappropriate shock therapy for non-ventricular arrhythmias is still a problem. Extending the ICD battery lifetime demands very low power consumption, which is obtained at very low microprocessor clock frequencies. Currently, some high-performance algorithms remain beyond the computational capabilities of ICDs. Future ICDs with higher computing power will permit the implementation of computationally intensive algorithms, enhancing the discrimination performance and preventing inappropriate shock therapies. An ICD algorithm status review is presented from the point of view of signal processing techniques and their computational costs. Several examples of discrimination algorithms with increasing computational cost are analyzed. Whereas some of them are already used in commercial ICDs, other algorithms cannot be implemented yet in current ICDs. A solution based on dynamic adaptation of microprocessor power consumption to meet algorithm computational requirements is proposed. This solution allows implementation of complex discrimination algorithms in ICDs without significantly increasing the power consumption.

Assessment of the classification capability of prediction and approximation methods for HRV analysis.

The goal of this paper is to examine the classification capabilities of various prediction and approximation methods and suggest which are most likely to be suitable for the clinical setting. Various prediction and approximation methods are applied in order to detect and extract those which provide the better differentiation between control and patient data, as well as members of different age groups. The prediction methods are local linear prediction, local exponential prediction, the delay times method, autoregressive prediction and neural networks. Approximation is computed with local linear approximation, least squares approximation, neural networks and the wavelet transform. These methods are chosen since each has a different physical basis and thus extracts and uses time series information in a different way.

New approaches to the assessment of left ventricular hypertrophy.

In hypertension, Left ventricular hypertrophy is initially a useful compensatory process that represents an adaptation to increased ventricular wall stress; however, it is also the first step toward the development of overt clinical disease. For this reason most international guidelines recommend the assessment of cardiac target organ damage in hypertensive patients for cardiovascular risk stratification. It is therefore of great importance to keep in mind the strengths and weakness of the different available methods for LVH assessment.Several methods are currently available for the assessment of LVH; however the various techniques differ in cost, availability, sensitivity and specificity. Due to its wide availability and its low cost, eLectrocardiography should be part of all routine assessment of subjects with high blood pressure; however, despite its good specificity, the sensitivity for LVH detection is low. Several other methods have been proposed for LVH detection. Cardiac magnetic resonance imaging allows 3D reconstruction of the heart with high spatial resolution; however its main limitation is represented by the relatively low availability and by its costs. Echocardiography certainly represents a valuable method for the detection of LVH in hypertensive patients, due to its wide availability and its relatively low cost. The main limitations of the technique are represented by the lower spatial resolution and reproducibility in comparison with magnetic resonance. The development of new matrix-array transducers and new software for 3D reconstruction with echocardiography make this approach particularly promising for the future; in the meantime, standard echocardiography, widely available and with low cost, will probably remain the most used tool for the evaluation of left ventricular structure and function in hypertension.

P wave assessment: state of the art update.

Diagnostic (mapping) and therapeutic (ablation, pacing) advances have provided insight into atrial depolarization processes and new developments in P wave analysis. Information about interatrial pathways is important to the understanding of interatrial conduction delay. A standardized method for P wave analysis is necessary for the development of a clinical role for management of patients with paroxysmal atrial fibrillation using signal-averaged P wave analysis and P wave dispersion. Algorithms for predicting localization of ectopic P waves may facilitate catheter ablation. P wave changes due to pacing at different atrial sites may be useful for permanent pacing for prevention of atrial fibrillation. Introduction of these developments into clinical practice should allow better prevention and treatment of atrial arrhythmias and could have considerable impact in view of their high frequency especially in the older population.

Telemetry monitoring in acute and critical care.

With the expansion of higher acuity patients in noncritical care areas, the perceived need for arrhythmia monitoring has also escalated. For institutions pursuing this expansion, many factors must be kept in mind, including patient criteria for telemetry initiation and discontinuation, staff competency of ECG interpretation, safety, technology required, usability, and cost effectiveness. All of these issues must be addressed according to the individual institution's needs and the needs of the patient populations they serve.