ORCID Profile
0000-0002-7146-7105
Current Organisation
University of Leeds
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Publisher: Research Square Platform LLC
Date: 08-01-2021
DOI: 10.21203/RS.3.RS-131749/V1
Abstract: Objective: Prevention of recurrent stroke in patients with embolic stroke of undetermined source (ESUS) is challenging. The advent of safer anticoagulation in the form of direct oral anticoagulants (DOACs) has prompted exploration of prophylactic anticoagulation for all ESUS patients, rather than anticoagulating just those with documented atrial fibrillation (AF). However, recent trials have failed to demonstrate a clinical benefit, while observing increased bleeding. We modeled the economic impact of anticoagulating ESUS patients without documented AF across multiple geographies. Methods: CRYSTAL-AF trial data were used to assess ischaemic stroke event rates in ESUS patients confirmed AF-free after long-term monitoring. Anticipated bleeding event rates (including both minor and major bleeds) with aspirin, dabigatran 150 mg, and rivaroxaban 20 mg were sourced from published meta-analyses, whilst a 30% ischaemic stroke reduction for both DOACs was assumed. Cost data for clinical events and pharmaceuticals were collected from the local payer perspective. Results: Compared with aspirin, dabigatran and rivaroxaban resulted in 17.9 and 29.9 additional bleeding events per 100 patients over a patient’s lifetime, respectively. Despite incorporating into our model the proposed 30% reduction in ischaemic stroke risk, both DOACs were cost-additive over patient lifetime, as the costs of bleeding events and pharmaceuticals outweighed cost savings associated with the reduction in ischaemic strokes. DOACs added £5,953-£7,018 per patient (UK), €6,683-€7,368 (Netherlands), €4,933-€9,378 (Spain), AUD$5,353-6,539 (Australia) and $26,768-$32,259 (US) of payer cost depending on the agent prescribed. Additionally, in the U.S. patient pharmacy co-payments ranged from $1,716-$12,473 depending on agent and patient plan. In all settings, cost-savings could not be demonstrated even when the modelling assumed 100% protection from recurrent ischaemic strokes, due to the very low underlying risk of recurrent ischaemic stroke in this population (1.27 per 100 patient-years). Conclusions: Anticoagulation of non-AF patients may cause excess bleeds and add substantial costs for uncertain benefits, suggesting a personalised approach to anticoagulation in ESUS patients.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-11-2020
Publisher: Elsevier BV
Date: 11-2019
DOI: 10.1016/J.JCHF.2019.06.011
Abstract: This study sought to evaluate the effects of the Carillon device on mitral regurgitation severity and left ventricular remodeling. Functional mitral regurgitation (FMR) complicates heart failure with reduced ejection fraction and is associated with a poor prognosis. In this blinded, randomized, proof-of-concept, sham-controlled trial, 120 patients receiving optimal heart failure medical therapy were assigned to a coronary sinus-based mitral annular reduction approach for FMR or sham. The pre-specified primary endpoint was change in mitral regurgitant volume at 12 months, measured by quantitative echocardiography according to an intention-to-treat analysis. Patients (69.8 ± 9.5 years of age) were randomized to either the treatment (n = 87) or the sham-controlled (n = 33) arm. There were no significant differences in baseline characteristics between the groups. In the treatment group, 73 of 87 (84%) had the device implanted. The primary endpoint was met, with a statistically significant reduction in mitral regurgitant volume in the treatment group compared to the control group (decrease of 7.1 ml/beat [95% confidence interval [CI]: -11.7 to -2.5] vs. an increase of 3.3 ml/beat [95% CI: -6.0 to 12.6], respectively p = 0.049). Additionally, there was a significant reduction in left ventricular volumes in patients receiving the device versus those in the control group (left ventricular end-diastolic volume decrease of 10.4 ml [95% CI: -18.5 to -2.4] vs. an increase of 6.5 ml [95% CI: -5.1 to 18.2] p = 0.03 and left ventricular end-systolic volume decrease of 6.2 ml [95% CI: -12.8 to 0.4] vs. an increase of 6.1 ml [95% CI: -1.42 to 13.6] p = 0.04). The Carillon device significantly reduced mitral regurgitant volume and left ventricular volumes in symptomatic patients with functional mitral regurgitation receiving optimal medical therapy. (Carillon Mitral Contour System for Reducing Functional Mitral Regurgitation [REDUCE FMR] NCT02325830).
Publisher: Wiley
Date: 12-2019
DOI: 10.1002/EHF2.12526
Publisher: Massachusetts Medical Society
Date: 12-11-2009
Publisher: Wiley
Date: 22-06-2021
DOI: 10.1002/JOA3.12586
Abstract: Detection of atrial fibrillation (AF) is required to initiate oral anticoagulation (OAC) after cryptogenic stroke (CS). However, paroxysmal AF can be difficult to diagnose with short term cardiac monitoring. Taking an Australian payer perspective, we evaluated whether long‐term continuous monitoring for 3 years with an insertable cardiac monitor (ICM) is cost‐effective for preventing recurrent stroke in patients with CS. A lifetime Markov model was developed to simulate the follow‐up of patients, comparing long‐term continuous monitoring with an ICM to monitoring by conventional care. We used a linked evidence approach to estimate the rates of recurrent stroke when AF detection leads to initiation of OAC, as detected using ICM during the lifetime of the device or as detected using usual care. All diagnostic and patient management costs were modeled. Other model inputs were determined by literature review. Probabilistic sensitivity analysis (PSA) was undertaken to explore the effect of parameter uncertainty according to CHADS 2 score and OAC treatment effect. In the base‐case analysis, the model predicted an incremental cost‐effectiveness ratio (ICER) of A$29 570 per quality‐adjusted life year (QALY). Among CHADS 2 subgroups analyses, the ICER ranged from A$26 342/QALY (CHADS 2 = 6) to A$42 967/QALY (CHADS 2 = 2). PSA suggested that the probabilities of ICM strategy being cost‐effective were 53.4% and 78.7%, at thresholds of $30 000 (highly cost‐effective) and $50 000 per QALY (cost‐effective), respectively. Long‐term continuous monitoring with an ICM is a cost‐effective intervention to prevent recurrent stroke in patients following CS in the Australian context.
Publisher: SAGE Publications
Date: 06-01-2016
Abstract: Documentation of atrial fibrillation is required to initiate oral anticoagulation therapy for recurrent stroke prevention. Atrial fibrillation often goes undetected with traditional electrocardiogram monitoring techniques. We evaluated whether atrial fibrillation detection using continuous long-term monitoring with an insertable cardiac monitor is cost-effective for preventing recurrent stroke in patients with cryptogenic stroke, in comparison to the standard of care. A lifetime Markov model was developed to estimate the cost-effectiveness of insertable cardiac monitors from a UK National Health Service perspective using data from the randomized CRYSTAL-AF trial and other published literature. We also conducted scenario analyses (CHADS 2 score) and probabilistic sensitivity analyses. All costs and benefits were discounted at 3.5%. Monitoring cryptogenic stroke patients with an insertable cardiac monitor was associated with fewer recurrent strokes and increased quality-adjusted life years compared to the standard of care (7.37 vs 7.22). Stroke-related costs were reduced in insertable cardiac monitor patients, but overall costs remained higher than the standard of care (£19,631 vs £17,045). The incremental cost-effectiveness ratio was £17,175 per quality-adjusted life years gained, compared to standard of care in the base-case scenario, which is below established quality-adjusted life years willingness-to-pay thresholds. When warfarin replaced non-vitamin-K oral anticoagulants as the main anticoagulation therapy, the incremental cost-effectiveness ratio was £13,296 per quality-adjusted life years gained. Insertable cardiac monitors are a cost-effective diagnostic tool for the prevention of recurrent stroke in patients with cryptogenic stroke. The cost-effectiveness results have relevance for the UK and across value-based healthcare systems that assess costs relative to outcomes.
Publisher: Springer Science and Business Media LLC
Date: 31-03-2021
DOI: 10.1186/S12872-021-01967-X
Abstract: Prevention of recurrent stroke in patients with embolic stroke of undetermined source (ESUS) is challenging. The advent of safer anticoagulation in the form of direct oral anticoagulants (DOACs) has prompted exploration of prophylactic anticoagulation for all ESUS patients, rather than anticoagulating just those with documented atrial fibrillation (AF). However, recent trials have failed to demonstrate a clinical benefit, while observing increased bleeding. We modeled the economic impact of anticoagulating ESUS patients without documented AF across multiple geographies. CRYSTAL-AF trial data were used to assess ischaemic stroke event rates in ESUS patients confirmed AF-free after long-term monitoring. Anticipated bleeding event rates (including both minor and major bleeds) with aspirin, dabigatran 150 mg, and rivaroxaban 20 mg were sourced from published meta-analyses, whilst a 30% ischaemic stroke reduction for both DOACs was assumed. Cost data for clinical events and pharmaceuticals were collected from the local payer perspective. Compared with aspirin, dabigatran and rivaroxaban resulted in 17.9 and 29.9 additional bleeding events per 100 patients over a patient’s lifetime, respectively. Despite incorporating into our model the proposed 30% reduction in ischaemic stroke risk, both DOACs were cost-additive over patient lifetime, as the costs of bleeding events and pharmaceuticals outweighed cost savings associated with the reduction in ischaemic strokes. DOACs added £5953–£7018 per patient (UK), €6683–€7368 (Netherlands), €4933–€9378 (Spain), AUD$5353–6539 (Australia) and $26,768–$32,259 (US) of payer cost depending on the agent prescribed. Additionally, in the U.S. patient pharmacy co-payments ranged from $2468–$12,844 depending on agent and patient plan. In all settings, cost-savings could not be demonstrated even when the modelling assumed 100% protection from recurrent ischaemic strokes, due to the very low underlying risk of recurrent ischaemic stroke in this population (1.27 per 100 patient-years). Anticoagulation of non-AF patients may cause excess bleeds and add substantial costs for uncertain benefits, suggesting a personalised approach to anticoagulation in ESUS patients.
Publisher: Elsevier BV
Date: 06-2020
Publisher: American Physiological Society
Date: 07-2018
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Klaus Witte.