Incremental Value of Aortomitral Continuity Calcification for Risk Assessment after Transcatheter Aortic Valve Replacement.

PURPOSE: To investigate the association of aortomitral continuity calcification (AMCC) with all-cause mortality, postprocedural paravalvular leak (PVL), and prolonged hospital stay in patients undergoing transcatheter aortic valve replacement (TAVR). MATERIALS AND METHODS: The authors retrospectively evaluated 329 patients who underwent TAVR between March 2013 and March 2016. AMCC, aortic valve calcification (AVC), and coronary artery calcification (CAC) were quantified by using preprocedural CT. Pre-procedural Society of Thoracic Surgeons (STS) score was recorded. Associations between baseline AMCC, AVC, and CAC and 1-year mortality, PVL, and hospital stay longer than 7 days were analyzed. RESULTS: The median follow-up was 415 days (interquartiles, 344-727 days). After 1 year, 46 of the 329 patients (14%) died and 52 (16%) were hospitalized for more than 7 days. Of the 326 patients who underwent postprocedural echocardiography, 147 (45%) had postprocedural PVL. The CAC score (hazard ratio: 1.11 per 500 points) and AMCC mass (hazard ratio: 1.13 per 500 mg) were associated with 1-year mortality. AVC mass (odds ratio: 1.93 per 100 mg) was associated with postprocedural PVL. Only the STS score was associated with prolonged hospital stay (odds ratio: 1.19 per point). CONCLUSION: AMCC is associated with mortality within 1 year after TAVR and substantially improves individual risk classification when added to a model consisting of STS score and AVC mass only.Supplemental material is available for this article.© RSNA, 2019See also the commentary by Brown and Leipsic in this issue.

Cost-effectiveness modelling in diagnostic imaging: a stepwise approach.

UNLABELLED: Diagnostic imaging (DI) is the fastest growing sector in medical expenditures and takes a central role in medical decision-making. The increasing number of various and new imaging technologies induces a growing demand for cost-effectiveness analysis (CEA) in imaging technology assessment. In this article we provide a comprehensive framework of direct and indirect effects that should be considered for CEA in DI, suitable for all imaging modalities. We describe and explain the methodology of decision analytic modelling in six steps aiming to transfer theory of CEA to clinical research by demonstrating key principles of CEA in a practical approach. We thereby provide radiologists with an introduction to the tools necessary to perform and interpret CEA as part of their research and clinical practice. KEY POINTS: • DI influences medical decision making, affecting both costs and health outcome. • This article provides a comprehensive framework for CEA in DI. • A six-step methodology for conducting and interpreting cost-effectiveness modelling is proposed.

Radiation exposure of abdominal cone beam computed tomography.

PURPOSE: To evaluate patients radiation exposure of abdominal C-arm cone beam computed tomography (CBCT). METHODS: This prospective study was approved by the institutional review board; written, informed consent was waived. Radiation exposure of abdominal CBCT was evaluated in 40 patients who underwent CBCT during endovascular interventions. Dose area product (DAP) of CBCT was documented and effective dose (ED) was estimated based on organ doses using dedicated Monte Carlo simulation software with consideration of X-ray field location and patients' individual body weight and height. Weight-dependent ED per DAP conversion factors were calculated. CBCT radiation dose was compared to radiation dose of procedural fluoroscopy. CBCT dose-related risk for cancer was assessed. RESULTS: Mean ED of abdominal CBCT was 4.3 mSv (95 % confidence interval [CI] 3.9; 4.8 mSv, range 1.1-7.4 mSv). ED was significantly higher in the upper than in the lower abdomen (p = 0.003) and increased with patients' weight (r = 0.55, slope = 0.045 mSv/kg, p < 0.001). Radiation exposure of CBCT corresponded to the radiation exposure of on average 7.2 fluoroscopy minutes (95 % CI 5.5; 8.8 min) in the same region of interest. Lifetime risk of exposure related cancer death was 0.033 % or less depending on age and weight. CONCLUSIONS: Mean ED of abdominal CBCT was 4.3 mSv depending on X-ray field location and body weight.

Cost-effectiveness of CTA, MRA and DSA in patients with non-traumatic subarachnoid haemorrhage.

OBJECTIVES: Intra-arterial digital subtraction angiography (DSA), magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) are imaging modalities used for diagnostic work-up of non-traumatic subarachnoid haemorrhage. The aim of our study was to compare the cost-effectiveness of MRA, DSA and CTA in the first year after the bleed. METHODS: A decision model was used to calculate costs and benefits (in quality-adjusted life-years [QALYs]) that accrued to cohorts of 1,000 patients. Costs and characteristics of diagnostic tests, therapy, patients' quality of life and associated costs were respected. The diagnostic strategy with highest QALYs and lowest costs was considered most cost-effective. RESULTS: DSA was the most effective diagnostic option, yielding on average 0.6039 QALYs (95 % CI, 0.5761-0.6327) per patient, followed by CTA 0.5983 QALYs (95 % CI, 0.5704-0.6278) and MRA 0.5947 QALYs (95 % CI, 0.5674-0.6237). Cost was lowest for DSA (39,808 ; 95 % CI, 37,182-42,663), followed by CTA (40,748 ; 95 % CI, 37,937-43,831) and MRA (41,814 ; 95 % CI, 38,730-45,146). A strategy of CTA followed by DSA if CTA was negative or coiling deemed not feasible, was as effective as DSA alone at average costs of 39,767 (95 % CI, 36,903-42,402). CONCLUSION: A combined strategy of CTA and DSA was found to be the most cost-effective diagnostic approach. MAIN MESSAGES: • We defined a standard model for cost-effectiveness analysis in diagnostic imaging. • Comparing total 1-year health costs and benefits, CTA is superior to MRA. • A strategy of combining CTA and DSA was found to be the most cost-effective diagnostic approach.