24 research outputs found
Using deep learning to optimize the prostate MRI protocol by assessing the diagnostic efficacy of MRI sequences
Purpose: To explore diagnostic deep learning for optimizing the prostate MRI protocol by assessing the diagnostic efficacy of MRI sequences. Method: This retrospective study included 840 patients with a biparametric prostate MRI scan. The MRI protocol included a T2-weighted image, three DWI sequences (b50, b400, and b800 s/mm2), a calculated ADC map, and a calculated b1400 sequence. Two accelerated MRI protocols were simulated, using only two acquired b-values to calculate the ADC and b1400. Deep learning models were trained to detect prostate cancer lesions on accelerated and full protocols. The diagnostic performances of the protocols were compared on the patient-level with the area under the receiver operating characteristic (AUROC), using DeLong's test, and on the lesion-level with the partial area under the free response operating characteristic (pAUFROC), using a permutation test. Validation of the results was performed among expert radiologists. Results: No significant differences in diagnostic performance were found between the accelerated protocols and the full bpMRI baseline. Omitting b800 reduced 53% DWI scan time, with a performance difference of + 0.01 AUROC (p = 0.20) and â0.03 pAUFROC (p = 0.45). Omitting b400 reduced 32% DWI scan time, with a performance difference of â0.01 AUROC (p = 0.65) and + 0.01 pAUFROC (p = 0.73). Multiple expert radiologists underlined the findings. Conclusions: This study shows that deep learning can assess the diagnostic efficacy of MRI sequences by comparing prostate MRI protocols on diagnostic accuracy. Omitting either the b400 or the b800 DWI sequence can optimize the prostate MRI protocol by reducing scan time without compromising diagnostic quality.</p
Mycobacterium chelonae, an âatypicalâ cause of an LVAD driveline infection
We describe the first patient with a left ventricular assist device (LVAD) driveline infection caused by Mycobacterium chelonae presenting with persistent infection despite conventional antibiotics. Treatment was successful with surgical debridement, driveline exit relocation, and a 4-month period of antibiotics. In the case of a culture-negative LVAD driveline infection, non-tuberculous mycobacteria should be considered. This case illustrates tha
Incidence of end-stage renal disease after heart transplantation and effect of its treatment on survival
Aims: Many heart transplant recipients will develop end-stage renal disease in the post-operative course. The aim of this study was to identify the long-term incidence of end-stage renal disease, determine its risk factors, and investigate what subsequent therapy was associated with the best survival. Methods and results: A retrospective, single-centre study was performed in all adult heart transplant patients from 1984 to 2016. Risk factors for end-stage renal disease were analysed by means of multivariable regression analysis and survival by means of KaplanâMeier. Of 685 heart transplant recipients, 71 were excluded: 64 were under 18 years of age and seven were re-transplantations. During a median follow-up of 8.6 years, 121 (19.7%) patients developed end-stage renal disease: 22 received conservative therapy, 80 were treated with dialysis (46 haemodialysis and 34 peritoneal dialysis), and 19 received a kidney transplant. Development of end-stage renal disease (examined as a time-dependent variable) inferred a hazard ratio of 6.45 (95% confidence interval 4.87â8.54, P < 0.001) for mortality. Tacrolimus-based therapy decreased, and acute kidney injury requiring renal replacement therapy increased the risk for end-stage renal disease development (hazard ratio 0.40, 95% confidence interval 0.26â0.62, P < 0.001, and hazard ratio 4.18, 95% confidence interval 2.30â7.59, P < 0.001, respectively). Kidney transplantation was associated with the best median survival compared with dialysis or conservative therapy: 6.4 vs. 2.2 vs. 0.3 years (P < 0.0001), respectively, after end-stage renal disease development. Conclusions: End-stage renal disease is a frequent complication after heart transplant and is associated with poor survival. Kidney transplantation resulted in the longest survival of patients with end-stage renal disease
The Association Between Cytomegalovirus Infection and Cardiac Allograft Vasculopathy in the Era of Antiviral Valganciclovir Prophylaxis
Background. Previous studies on the association between cytomegalovirus (CMV) infection and cardiac allograft vasculopathy (CAV) were conducted on patients transplanted in the prevalganciclovir prophylaxis era. The aim of our study is
to evaluate this relation in heart transplantation (HTx) recipients treated according to current prophylactic and immunosuppressive regimens. Methods. This single-center retrospective study included all consecutive adult patients that underwent
HTx between January 1, 2000, and May 31, 2018. Clinically relevant CMV infection was defined as either plasma CMV
DNAemia â„ 1000 IU/mL with/without clinical symptoms or <1000 IU/mL with symptoms. The primary endpoint was first
manifestation of CAV diagnosed by coronary angiography. For statistical analysis, the cause-specific hazard regression
model was applied, with clinically relevant CMV infection and any CMV infection as time-dependent variables. Results. In
total, 260 patients were included in the analysis. The median (interquartile range) follow-up was 7.88 (4.21â12.04) years.
During the follow-up, clinically relevant CMV infection was diagnosed in 96 (37%) patients and CAV in 149 (57%) patients.
In the multivariate regression analysis, independent predictors of CAV were: number of rejection episodes (cause-specific
hazard ratio [95% confidence interval]: 1.18 [1.04-1.34], P = 0.01), hypertension (1.61 [1.11-2.34], P = 0.01), treatment with
mycophenolate mofetil (0.68 [0.47-0.97], P = 0.03). No significant association was observed between CMV infection and
CAV, except for patients who experienced a breakthrough CMV infection (n = 24) during prophylaxis (1.94 [1.11-3.40], P =
0.02). Conclusions. In the era of contemporary immunosuppression and valganciclovir prophylaxis, a signifi
Heart failure and promotion of physical activity before and after cardiac rehabilitation (HF-aPProACH):a study protocol
Abstract Aims Lifestyle changes, such as increasing physical activity (PA), are a cornerstone of treatment of patients with chronic heart failure (HF). However, improving PA in HF patients is challenging, and low participation rates for cardiac rehabilitation (CR) as well as relapse to low PA levels after CR are major issues. We designed a randomized controlled trial to investigate if PA monitoring with motivational feedback before and after centreâbased CR in HF patients with reduced ejection fraction (HFrEF) will lead to a clinically meaningful increase in physical fitness. Methods and results A randomized controlled trial will be conducted in a sample of 180 HFrEF patients (New York Heart Association Class II/III) who are referred to 12âweek standard CR. Patients will be randomized (2:1) to (1) standard of care (SoC) plus wearing a PA monitoring device (Fitbit Charge 3) with personalized step goals, feedback and motivation or (2) SoC only. The intervention lasts ±7 months: 4â5 weeks before CR, 12 weeks during CR and 12 weeks after CR. Measurements will take place at three time points. The primary endpoint is the change in the distance in 6âmin walking test (6MWT) over the entire study period. Other endpoints include step count, grip strength, quality of life and allâcause mortality or hospitalization. Conclusions HFâaPProACH will provide novel information on the effectiveness of remote PA stimulation and feedback before, during and after standard CR using a commercially available device to improve physical fitness in HFrEF patients
Pharmacological inhibition of TBK1/IKKΔ blunts immunopathology in a murine model of SARS-CoV-2 infection
TANK-binding kinase 1 (TBK1) is a key signalling component in the pro-duction of type-I interferons, which have essential antiviral activities,including against SARS-CoV-2. TBK1, and its homologue IÎșB kinase-Δ (IKKΔ), can also induce pro-inflammatory responses that contribute to pathogen clearance. While initially protective, sustained engagement of type-I interferons is associated with damaging hyper-inflammation found in severe COVID-19 patients. The contribution of TBK1/IKKΔ signalling to these responses is unknown. Here we find that the small molecule idronoxil inhibits TBK1/IKKΔ signalling through destabilisation of TBK1/IKKΔ protein complexes. Treatment with idronoxil, or the small molecule inhibitor MRT67307, suppresses TBK1/IKKΔ signalling and attenuates cellular and molecular lung inflammation in SARS-CoV-2-challenged mice. Our findings additionally demonstrate that engagement of STING is not the major driver of these inflammatory responses and establish a critical role for TBK1/IKKΔ signalling in SARS-CoV-2 hyper inflammation
Routine clinical cardiovascular magnetic resonance in paediatric and adult congenital heart disease: patients, protocols, questions asked and contributions made
<p>Abstract</p> <p>Background</p> <p>Cardiovascular Magnetic Resonance (CMR) of patients with congenital heart disease (CHD) has become routine clinical practice. However, existing CMR protocols focus predominantly on patients with ischemic heart disease, and information is limited on the types of patient with CHD who benefit from CMR investigation, and in what ways. Therefore the aim of this study was to answer the questions: What type of patients were studied by CMR in a centre specializing in paediatric and adult CHD management? What questions were asked, which protocols were used and were the questions successfully answered? To answer these questions, we conducted a cohort study of all 362 patients that received routine clinical CMR during 2007 at the Department of Paediatric Cardiology and Congenital Heart Disease at the Deutsches Herzzentrum MĂŒnchen.</p> <p>Results</p> <p>Underlying diagnosis was in 33% Fallot's tetralogy, 17% aortic coarctation, 8% Ebstein's disease, 6% Marfan's disease, 4% single ventricle with Fontan-like circulation, and 32% others. Median age was 26 years (7 days â 75 years). Ventricular volumes were assessed in 67% of the patients; flow in 74%; unknown anatomy only in 9%; specific individual morphology of known anatomy in 83%; myocardial fibrosis in 8%; stress-induced myocardial perfusion defects in 1%. Only in 3% of the cases the question could not be fully answered.</p> <p>Conclusion</p> <p>Contrary to common belief, routine CMR of patients with CHD was not requested to address global anatomical questions so much as to clarify specific questions of morphology and function of known anatomy. The CMR protocols used differed markedly from those widely used in patients with ischemic heart disease.</p
Serial Coronary Imaging of Early Atherosclerosis Development in Fast-Food-Fed Diabetic and Nondiabetic Swine
Patients with diabetes mellitus (DM) are at increased risk for atherosclerosis-related events compared to non-DM (NDM) patients. With an expected worldwide epidemic of DM, early detection of anatomic and functional coronary atherosclerotic changes is gaining attention. To improve our understanding of early atherosclerosis development, we studied a swine model that gradually developed coronary atherosclerosis. Interestingly, optical coherence tomography, near-infrared spectroscopy (NIRS), vascular function, and histology demonstrated no differences between development of early atherosclerosis in fast-food-fed (FF) DM swine and that in FF-NDM swine. Coronary computed tomography angiography did not detect early atherosclerosis, but optical coherence tomography and near-infrared spectroscopy demonstrated coronary atherosclerosis development in FF-DM and FF-NDM swine