Real-time pulmonary artery pressure monitoring in heart failure patients: an updated cost-effectiveness analysis.

AIMS: Previous cost-effectiveness analysis suggests that CardioMEMS is cost-effective compared with usual care for patients with persistent New York Heart Association class III symptoms and at least one heart failure (HF) hospitalization within 12 months. The aim of the paper is to perform an update of the cost-effectiveness analysis of CardioMEMS using the most recent data from the published literature. METHODS AND RESULTS: A Microsoft Excel Markov model from a previous UK cost-effectiveness study of CardioMEMS was updated using the clinical effectiveness of pulmonary artery pressure (PAP)-guided treatment derived from the pivotal trials. The model included the device costs (and the implantation procedure and related complications), costs of remote monitoring, costs of HF-related hospitalizations, and costs of usual care. Quality-adjusted life years (QALYs) were estimated based on utilities from pivotal trials and published literature. Cost-effectiveness results were estimated as incremental cost per QALY gained of CardioMEMS compared with usual care. Scenario analyses were also performed using data from real-world studies that showed a significant decrease in HF-related hospitalizations. In the base case analysis over a time horizon of 10 years, PAP-guided HF therapy increased cost compared with usual care by £6337 (i.e. from £22 770 in usual care to £29 107 in PAP-guided HF therapy) and the QALYs per patient for usual care and PAP-guided patients were 2.62 and 2.94, respectively, reflecting an increase of 0.32 QALYs with PAP-guided treatment. The resultant incremental cost-effectiveness ratio (ICER), the ratio between incremental costs and the QALYs, is estimated at £19 761/QALY. Scenario analyses suggest that the ICER for CardioMEMS can range from being dominant to £27 910/QALY. Probabilistic sensitivity analyses suggested that PAP-guided HF therapy has 81.9% probability of being cost-effective at a threshold of £30 000/QALY. CONCLUSIONS: Our model suggests that CardioMEMS is likely to be cost-effective in the United Kingdom, at the currently considered thresholds of £20 000-30 000/QALY.

Economic value of narrow-band imaging versus white light endoscopy for the diagnosis and surveillance of Barrett's esophagus: Cost-consequence model.

Barrett's esophagus (BE) is an abnormality arising from gastroesophageal reflux disease that can progressively evolve into a sequence of dysplasia and adenocarcinoma. Progression of Barrett's esophagus into dysplasia is monitored with endoscopic surveillance. The current surveillance standard requests random biopsies plus targeted biopsies of suspicious lesions under white-light endoscopy, known as the Seattle protocol. Recently, published evidence has shown that narrow-band imaging (NBI) can guide targeted biopsies to identify dysplasia and reduce the need for random biopsies. We aimed to assess the health economic implications of adopting NBI-guided targeted biopsy vs. the Seattle protocol from a National Health Service England perspective. A decision tree model was developed to undertake a cost-consequence analysis. The model estimated total costs (i.e. staff and overheads; histopathology; adverse events; capital equipment) and clinical implications of monitoring a cohort of patients with known/suspected BE, on an annual basis. In the simulation, BE patients (N = 161,657 at Year 1; estimated annual increase: +20%) entered the model every year and underwent esophageal endoscopy. After 7 years, the adoption of NBI with targeted biopsies resulted in cost reduction of £458.0 mln vs. HD-WLE with random biopsies (overall costs: £1,966.2 mln and £2,424.2 mln, respectively). The incremental investment on capital equipment to upgrade hospitals with NBI (+£68.3 mln) was offset by savings due to the reduction of histological examinations (-£505.2 mln). Reduction of biopsies also determined savings for avoided adverse events (-£21.1 mln). In the base-case analysis, the two techniques had the same accuracy (number of correctly identified cases: 1.934 mln), but NBI was safer than HD-WLE. Budget impact analysis and cost-effectiveness analyses confirmed the findings of the cost-consequence analysis. In conclusion, NBI-guided targeted biopsies was a cost-saving strategy for NHS England, compared to current practice for detection of dysplasia in patients with BE, whilst maintaining at least comparable health outcomes for patients.

Economic Value of the Transurethral Resection in Saline System for Treatment of Benign Prostatic Hyperplasia in England and Wales: Systematic Review, Meta-analysis, and Cost-Consequence Model.

CONTEXT: Monopolar transurethral resection of the prostate (M-TURP) is the current UK surgical standard of care for benign prostatic hyperplasia, a condition estimated to affect >2 million men in the United Kingdom. Although M-TURP efficacy in prostate resection is established, potential perioperative complications and associated costs remain a concern. OBJECTIVE: To present up-to-date and robust evidence in support of bipolar transurethral resection in saline (TURis) as an alternative surgical option to M-TURP. EVIDENCE ACQUISITION: A systematic review (SR) of electronic databases (up to 2015) for randomised controlled trials (RCTs) comparing TURis with M-TURP was conducted, followed by evidence synthesis in the form of a meta-analysis of hospital stay, catheterisation time and procedure duration, transurethral resection (TUR) syndrome, blood transfusion, clot retention, and urethral strictures. An economic analysis was subsequently undertaken from the UK National Health Service hospital perspective with costs and resource use data from published sources. EVIDENCE SYNTHESIS: The SR identified 15 good-quality RCTs, of which 11 were used to inform the meta-analysis. TURis was associated with improved safety versus M-TURP, eliminating the risk of TUR syndrome and reducing the risk of blood transfusion and clot retention (relative risks: 0.34 and 0.43, respectively; p<0.05). TURis also reduced hospital stay (mean difference: 0.56 d; p<0.0001). The economic analysis indicated potential cost savings with TURis versus M-TURP of up to £204 per patient, with incremental equipment costs offset by savings from reduced hospital stay and fewer complications. CONCLUSIONS: The TURis system is associated with significant improvements in perioperative safety compared with M-TURP while ensuring equivalent clinical outcomes of prostate resection. The safety benefits identified may translate into cost savings for UK health services. PATIENT SUMMARY: Our review of bipolar transurethral resection in saline, the new prostate resection technique, indicates that it offers equal efficacy while reducing complications and length of hospital stay.

Economic value of narrow band imaging versus white light endoscopy for the characterization of diminutive polyps in the colon: systematic literature review and cost-consequence model.

AIMS: To demonstrate the economic implication of adopting narrow-band imaging (NBI) for the characterization of diminutive polyps in the colon from an English payer perspective. MATERIALS AND METHODS: A decision-tree model was undertaken to perform a cost-consequence and budget impact analysis from the NHS England perspective in the UK, over a 7-year time horizon. Clinical inputs came from the published literature (both randomized controlled trials and meta-analyses) identified through a systematic literature review, and cost inputs came from national list prices and unpublished internal market data. Deterministic sensitivity analysis (DSA) was conducted on the budget impact results to assess their robustness. RESULTS: Optical diagnosis with NBI offered cost savings vs white light endoscopy (WLE) over 7 years due to reductions in histological exams, resections, and associated adverse events, while having minimal impact on health outcomes. Budget impact analysis demonstrated annual cost savings of £141 192 057 over 7 years, with histological exams being the biggest cost driver. DSA showed these results to be robust, but most sensitive to the cost of tariff with and without biopsy, and the cost of histological exam. Break-even analysis to explore how changing the unit cost and number of biopsies per patient would change the budget impact found NBI consistently offered net savings, even if the cost of biopsy was £0. LIMITATIONS: Although every effort was made to ensure robustness of results, as with any model, there were some limitations including a lack of published data for certain clinical inputs and potential variation between model inputs and real-life cost and market share values. CONCLUSIONS: Optical diagnosis with NBI was found to be equally effective compared with the standard of care (WLE), while potentially enabling cost savings from the NHS England perspective.

Difference in percentage of ventricular pacing between two algorithms for minimizing ventricular pacing: results of the IDEAL RVP (Identify the Best Algorithm for Reducing Unnecessary Right Ventricular Pacing) study.

AIMS: Managed ventricular pacing (MVP) and Search AV+ are representative dual-chamber pacing algorithms for minimizing ventricular pacing (VP). This randomized, crossover study aimed to examine the difference in ability to reduce percentage of VP (%VP) between these two algorithms. METHODS AND RESULTS: Symptomatic bradyarrhythmia patients implanted with a pacemaker equipped with both algorithms (Adapta DR, Medtronic) were enrolled. The %VPs of the patients during two periods were compared: 1 month operation of either one of the two algorithms for each period. All patients were categorized into subgroups according to the atrioventricular block (AVB) status at baseline: no AVB (nAVB), first-degree AVB (1AVB), second-degree AVB (2AVB), episodic third-degree AVB (e3AVB), and persistent third-degree AVB (p3AVB). Data were available from 127 patients for the analysis. For all patient subgroups, except for p3AVB category, the median %VPs were lower during the MVP operation than those during the Search AV+ (nAVB: 0.2 vs. 0.8%, P < 0.0001; 1AVB: 2.3 vs. 27.4%, P = 0.001; 2AVB: 16.4% vs. 91.9%, P = 0.0052; e3AVB: 37.7% vs. 92.7%, P = 0.0003). CONCLUSION: Managed ventricular pacing algorithm, when compared with Search AV+, offers further %VP reduction in patients implanted with a dual-chamber pacemaker, except for patients diagnosed with persistent loss of atrioventricular conduction.

Quantitative assessment of dyssynchrony using ECG-gated SPECT myocardial perfusion imaging prior to and following cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) assists patients with advanced heart failure (HF) by improving left ventricular (LV) dyssynchrony, but there are significant numbers of non-responders, 1 reason being that the QRS duration is used as the only surrogate determinant of mechanical dyssynchrony, so an effective indicator of LV dyssynchrony is required. The present patient, who had HF, underwent CRT and showed clinical improvement with marked LV reverse remodeling. The regional contraction timing in the LV was assessed with software developed in an application on ECG-gated SPECT myocardial perfusion imaging that depicts the time-volume relationship of the segmented ventricular myocardium and the dispersion of time to end-systole as an expression of dyssynchrony. It was reduced in this patient following CRT. Discordance of systole in regional myocardial segments may present as mechanical dyssynchrony in the LV and could be used as an alternative to QRS duration. Quantitative assessment of dyssynchrony may be possible using this novel method, but further evaluation of the methodology is required.

Vectorcardiographic lead systems for the characterization of atrial fibrillation.

OBJECTIVE: The aim of the study was to design a vectorcardiographic lead system dedicated to the analysis of atrial fibrillation (AF). METHODS: Body surface potentials during AF were simulated by using a biophysical model of the human atria and thorax. The XYZ components of the equivalent dipole were derived from the Gabor-Nelson equations. These served as the gold standard while searching for an optimal orthogonal lead system for the estimation of the heart vector while using a limited number of electrode positions. Six electrode configurations and their dedicated transfer matrices were tested by using 10 different episodes of simulated AF and 25 different thorax geometries. RESULTS: Root-mean-square-based relative estimation error of the vectorcardiogram using the Frank electrodes was 0.39. An adaptation of 4 of the 9 electrode locations of the standard electrocardiogram, with 1 electrode moved to the back, reduced the error to 0.24. CONCLUSION: The Frank lead system is suboptimal for estimating the equivalent dipole components (VCG) during AF. Alternative electrode configurations should include at least 1 electrode on the back.

Adaptation of the standard 12-lead electrocardiogram system dedicated to the analysis of atrial fibrillation.

OBJECTIVE: The objective of the study was to design a lead system aimed at studying atrial fibrillation (AF), while being anchored to the standard 12-lead system. METHODS: The location of 4 of the 6 precordial electrodes was optimized while leaving the remaining 5 of the 9 electrodes of the standard 12-lead system in place. The analysis was based on episodes of 11 different variants of AF simulated by a biophysical model of the atria positioned inside an inhomogeneous thorax. The optimization criterion used was derived from the singular value decomposition of the data matrices. RESULTS: While maintaining VR, VL, VF, V1 and V4, the 4 new electrode positions increased the ratio of the eighth and the first singular values of the data matrices of the new configuration about 5-fold compared with that of the conventional electrode positions. CONCLUSION: The adapted lead system produces a more complete view on AF compared with that of the standard 12-lead system.

Atrial repolarization as observable during the PQ interval.

OBJECTIVE: We aimed to study the involvement of atrial repolarization in body surface potentials. METHODS: Electrocardiograms of healthy subjects were recorded using a 64-lead system. The data analysis focused on the PQ intervals while devoting special attention to the low-amplitude signals during the PQ segment: the segment from the end of the P wave until onset QRS. The data were analyzed by inspecting body surface potential maps and the XYZ signals of the vectorcardiogram. RESULTS: Standard P-wave features exhibited normal values. The local potential extremes were found at positions not sampled by the standard leads. The PQ segment was found to be not isoelectric, the time course of the potential distribution being very similar to that during the P wave but for a reversed polarity and about 3-fold lower magnitudes. CONCLUSION: The results demonstrate a significant involvement of atrial repolarization during the PQ interval and essentially discordant "atrial T waves," suggesting a small dispersion of atrial action potential durations.

Study of unipolar electrogram morphology in a computer model of atrial fibrillation.

INTRODUCTION: Electrograms exhibit a wide variety of morphologies during atrial fibrillation (AF). The basis of these time courses, however, is not completely understood. In this study, data from computer models were studied to relate features of the signals to the underlying dynamics and tissue substrate. METHODS AND RESULTS: A computer model of entire human atria with a gross fiber architecture based on histology and membrane kinetics based on the Courtemanche et al. atrial model was developed to simulate paced activation and simulated AF. Unipolar electrograms were computed using a current source approximation at 256 sites in right atrium, to simulate a mapping array. The results show the following: (1) In a homogeneous and isotropic tissue, the presence of highly asymmetric electrograms is rare (<2%), although there is a marked variability in amplitude and symmetry. (2) The introduction of anisotropy increases this variability in symmetry and amplitude of the, electrograms especially for propagation across fibers. The percentage of highly asymmetric electrograms increases to 12% to 15% for anisotropy ratios greater than 3:1. (3) Multiphasic and fractionated electrograms are rarely seen in the model with uniform properties but are more common (15%-17%) in a model including regions with abrupt changes in conductivity. Beat-to-beat variations in the occurrence of multiphasic signals are possible with fixed anatomic heterogeneity, due to beat-to-beat variations in the direction of the wavefront relative to the heterogeneity. CONCLUSION: Analysis of the amplitude and symmetry of unipolar atrial electrograms can provide information about the electrophysiologic substrate maintaining AF.