Recovering Homography from Camera Captured Documents using Convolutional Neural Networks

Removing perspective distortion from hand held camera captured document images is one of the primitive tasks in document analysis, but unfortunately, no such method exists that can reliably remove the perspective distortion from document images automatically. In this paper, we propose a convolutional neural network based method for recovering homography from hand-held camera captured documents. Our proposed method works independent of document's underlying content and is trained end-to-end in a fully automatic way. Specifically, this paper makes following three contributions: Firstly, we introduce a large scale synthetic dataset for recovering homography from documents images captured under different geometric and photometric transformations; secondly, we show that a generic convolutional neural network based architecture can be successfully used for regressing the corners positions of documents captured under wild settings; thirdly, we show that L1 loss can be reliably used for corners regression. Our proposed method gives state-of-the-art performance on the tested datasets, and has potential to become an integral part of document analysis pipeline.Comment: 10 pages, 8 figure

Does Heterogeneity Exist in Treatment Associations With Renin–Angiotensin–System Inhibitors or Beta-blockers According to Phenotype Clusters in Heart Failure with Preserved Ejection Fraction?

BACKGROUND: We explored the association between use of renin–angiotensin system inhibitors and beta-blockers, with mortality/morbidity in 5 previously identified clusters of patients with heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: We analyzed 20,980 patients with HFpEF from the Swedish HF registry, phenotyped into young–low comorbidity burden (12%), atrial fibrillation–hypertensive (32%), older–atrial fibrillation (24%), obese–diabetic (15%), and a cardiorenal cluster (17%). In Cox proportional hazard models with inverse probability weighting, there was no heterogeneity in the association between renin–angiotensin system inhibitor use and cluster membership for any of the outcomes: cardiovascular (CV) mortality, all-cause mortality, HF hospitalisation, CV hospitalisation, or non-CV hospitalisation. In contrast, we found a statistical interaction between beta-blocker use and cluster membership for all-cause mortality (P = .03) and non-CV hospitalisation (P = .001). In the young–low comorbidity burden and atrial fibrillation–hypertensive cluster, beta-blocker use was associated with statistically significant lower all-cause mortality and non-CV hospitalisation and in the obese–diabetic cluster beta-blocker use was only associated with a statistically significant lower non-CV hospitalisation. The interaction between beta-blocker use and cluster membership for all-cause mortality could potentially be driven by patients with improved EF. However, patient numbers were diminished when excluding those with improved EF and the direction of the associations remained similar. CONCLUSIONS: In patients with HFpEF, the association with all-cause mortality and non-CV hospitalisation was heterogeneous across clusters for beta-blockers. It remains to be elucidated how heterogeneity in HFpEF could influence personalized medicine and future clinical trial design

Drug-resistant genotypes and multi-clonality in Plasmodium falciparum analysed by direct genome sequencing from peripheral blood of malaria patients.

Naturally acquired blood-stage infections of the malaria parasite Plasmodium falciparum typically harbour multiple haploid clones. The apparent number of clones observed in any single infection depends on the diversity of the polymorphic markers used for the analysis, and the relative abundance of rare clones, which frequently fail to be detected among PCR products derived from numerically dominant clones. However, minority clones are of clinical interest as they may harbour genes conferring drug resistance, leading to enhanced survival after treatment and the possibility of subsequent therapeutic failure. We deployed new generation sequencing to derive genome data for five non-propagated parasite isolates taken directly from 4 different patients treated for clinical malaria in a UK hospital. Analysis of depth of coverage and length of sequence intervals between paired reads identified both previously described and novel gene deletions and amplifications. Full-length sequence data was extracted for 6 loci considered to be under selection by antimalarial drugs, and both known and previously unknown amino acid substitutions were identified. Full mitochondrial genomes were extracted from the sequencing data for each isolate, and these are compared against a panel of polymorphic sites derived from published or unpublished but publicly available data. Finally, genome-wide analysis of clone multiplicity was performed, and the number of infecting parasite clones estimated for each isolate. Each patient harboured at least 3 clones of P. falciparum by this analysis, consistent with results obtained with conventional PCR analysis of polymorphic merozoite antigen loci. We conclude that genome sequencing of peripheral blood P. falciparum taken directly from malaria patients provides high quality data useful for drug resistance studies, genomic structural analyses and population genetics, and also robustly represents clonal multiplicity

Trajectories in New York Heart Association functional class in heart failure across the ejection fraction spectrum: data from the Swedish Heart Failure Registry.

AIMS: To investigate incidence, predictors and prognostic implications of longitudinal New York Heart Association (NYHA) class changes (i.e. improving or worsening vs. stable NYHA class) in heart failure (HF) across the ejection fraction (EF) spectrum. METHODS AND RESULTS: From the Swedish HF Registry, 13 535 patients with EF and ≥2 NYHA class assessments were considered. Multivariable multinomial regressions were fitted to identify the independent predictors of NYHA change. Over a 1-year follow-up, 69% of patients had stable, 17% improved, and 14% worsened NYHA class. Follow-up in specialty care predicted improving NYHA class, whereas an in-hospital patient registration, lower EF, renal disease, lower mean arterial pressure, older age, and longer HF duration predicted worsening. The association between NYHA change and subsequent outcomes was assessed with multivariable Cox models. When adjusting for the NYHA class at baseline, improving NYHA class was independently associated with lower while worsening with higher risk of all-cause and cardiovascular mortality, and first HF hospitalization. After adjustment for the NYHA class at follow-up, NYHA class change did not predict morbidity/mortality. NYHA class assessment at baseline and follow-up predicted morbidity/mortality on top of the changes. Results were consistent across the EF spectrum. CONCLUSION: In a large real-world HF population, NYHA class trajectories predicted morbidity/mortality after extensive adjustments. However, the prognostic role was entirely explained by the resulting NYHA class, i.e. the follow-up value. Our results highlight that considering one-time NYHA class assessment, rather than trajectories, might be the preferable approach in clinical practice and for clinical trial design

Association between dosing and combination use of medications and outcomes in heart failure with reduced ejection fraction: data from the Swedish Heart Failure Registry.

AIMS: To assess the association between combination, dose and use of current guideline-recommended target doses (TD) of renin-angiotensin system inhibitors (RASi), angiotensin receptor-neprilysin inhibitors (ARNi) and β-blockers, and outcomes in a large and unselected contemporary cohort of patients with heart failure (HF) and reduced ejection fraction. METHODS AND RESULTS: Overall, 17 809 outpatients registered in the Swedish Heart Failure Registry (SwedeHF) from May 2000 to December 2018, with ejection fraction <40% and duration of HF ≥90 days were selected. Primary outcome was a composite of time to cardiovascular death and first HF hospitalization. Compared with no use of RASi or ARNi, the adjusted hazard ratio (HR) (95% confidence interval [CI]) was 0.83 (0.76-0.91) with <50% of TD, 0.78 (0.71-0.86) with 50%-99%, and 0.73 (0.67-0.80) with ≥100% of TD. Compared with no use of β-blockers, the adjusted HR (95% CI) was 0.86 (0.76-0.91), 0.81 (0.74-0.89) and 0.74 (0.68-0.82) with <50%, 50%-99% and ≥100% of TD, respectively. Patients receiving both an angiotensin-converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB)/ARNi and a β-blocker at 50%-99% of TD had a lower adjusted risk of the primary outcome compared with patients only receiving one drug, i.e. ACEi/ARB/ARNi or β-blocker, even if this was at ≥100% of TD. CONCLUSION: Heart failure with reduced ejection fraction patients using higher doses of RASi or ARNi and β-blockers had lower risk of cardiovascular death or HF hospitalization. Use of two drug classes at 50%-99% of TD dose was associated with lower risk than one drug class at 100% of TD

Digoxin use in contemporary heart failure with reduced ejection fraction: an analysis from the Swedish Heart Failure Registry.

AIMS: Digoxin is included in some heart failure (HF) guidelines but controversy persists about the true role for and impact of treatment with this drug, particularly in the absence of atrial fibrillation (AF). The aim of this study was to assess the association between clinical characteristics and digoxin use and between digoxin use and mortality/morbidity in a large, contemporary cohort of patients with HF with reduced ejection fraction (HFrEF) stratified by history of AF. METHODS AND RESULTS: Patients with HFrEF (EF < 40%) enrolled in the Swedish HF registry between 2005 and 2018 were analysed. The independent association between digoxin use and patient characteristics was assessed by logistic regression, and between digoxin use and outcomes [composite of all-cause mortality or HF hospitalization (HFH), all-cause mortality, and HFH] by Cox regressions in a 1:1 propensity score matched population. Digoxin use was analysed at baseline and as a time-dependent variable. Of 42 456 patients with HFrEF, 16% received digoxin, 29% in the AF group and 2.8% in the non-AF group. The main independent predictors of use were advanced HF, higher heart rate, history of AF, preserved renal function, and concomitant use of beta blockers. Digoxin use was associated with lower risk of all-cause death/HFH [hazard ratio (HR): 0.95; 95% confidence interval (CI): 0.91-0.99] in AF, but with higher risk in non-AF (HR: 1.24; 95% CI: 1.09-1.43). Consistent results were observed when digoxin use was analysed as a time-dependent variable. CONCLUSION: The great majority of digoxin users had a history of AF. Digoxin use was associated with lower mortality/morbidity in patients with AF, but with higher mortality/morbidity in patients without AF

Patient profile and outcomes associated with follow-up in specialty vs. primary care in heart failure.

AIMS: Factors influencing follow-up referral decisions and their prognostic implications are poorly investigated in patients with heart failure (HF) with reduced (HFrEF), mildly reduced (HFmrEF), and preserved (HFpEF) ejection fraction (EF). We assessed (i) the proportion of, (ii) independent predictors of, and (iii) outcomes associated with follow-up in specialty vs. primary care across the EF spectrum. METHODS AND RESULTS: We analysed 75 518 patients from the large and nationwide Swedish HF registry between 2000-2018. Multivariable logistic regression models were fitted to identify the independent predictors of planned follow-up in specialty vs. primary care, and multivariable Cox models to assess the association between follow-up type and outcomes. In this nationwide registry, 48 115 (64%) patients were planned for follow-up in specialty and 27 403 (36%) in primary care. The median age was 76 [interquartile range (IQR) 67-83] years and 27 546 (36.5%) patients were female. Key independent predictors of planned follow-up in specialty care included optimized HF care, that is follow-up in a nurse-led HF clinic [odds ratio (OR) 4.60, 95% confidence interval (95% CI) 4.41-4.79], use of HF devices (OR 3.99, 95% CI 3.62-4.40), beta-blockers (OR 1.39, 95% CI 1.32-1.47), renin-angiotensin system/angiotensin-receptor-neprilysin inhibitors (OR 1.21, 95% CI 1.15-1.27), and mineralocorticoid receptor antagonists (OR 1.31, 95% CI 1.26-1.37); and more severe HF, that is higher NT-proBNP (OR 1.13, 95% CI 1.06-1.20) and NYHA class (OR 1.13, 95% CI 1.08-1.19). Factors associated with lower likelihood of follow-up in specialty care included older age (OR 0.29, 95% CI 0.28-0.30), female sex (OR 0.89, 95% CI 0.86-0.93), lower income (OR 0.79, 95% CI 0.76-0.82) and educational level (OR 0.77, 95% CI 0.73-0.81), higher EF [HFmrEF (OR 0.65, 95% CI 0.62-0.68) and HFpEF (OR 0.56, 95% CI 0.53-0.58) vs. HFrEF], and higher comorbidity burden, such as presence of kidney disease (OR 0.91, 95% CI 0.87-0.95), atrial fibrillation (OR 0.85, 95% CI 0.81-0.89), and diabetes mellitus (OR 0.92, 95% CI 0.88-0.96). A planned follow-up in specialty care was independently associated with lower risk of all-cause [hazard ratio (HR) 0.78, 95% CI 0.76-0.80] and cardiovascular death (HR 0.76, 95% CI 0.73-0.78) across the EF spectrum, but not of HF hospitalization (HR 1.06, 95% CI 1.03-1.10). CONCLUSIONS: In a large nationwide HF population, referral to specialty care was linked with male sex, younger age, lower EF, lower comorbidity burden, better socioeconomic environment and optimized HF care, and associated with better survival across the EF spectrum. Our findings highlight the need for greater and more equal access to HF specialty care and improved quality of primary care

Use of and association between heart failure pharmacological treatments and outcomes in obese versus non-obese patients with heart failure with reduced ejection fraction: data from the Swedish Heart Failure Registry.

AIMS: To investigate the use of guideline-directed medical therapies (GDMT) and associated outcomes in obese (body mass index ≥30 kg/m2 ) versus non-obese patients with heart failure (HF) with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Patients with HFrEF from the Swedish HF Registry were included. Of 16 116 patients, 24% were obese. In obese versus non-obese patients, use of treatments was 91% versus 86% for renin-angiotensin system inhibitors (RASi)/angiotensin receptor-neprilysin inhibitors (ARNi), 94% versus 91% for beta-blockers, 53% versus 43% for mineralocorticoid receptor antagonists. Obesity was shown to be independently associated with more likely use of each treatment, triple combination therapy, and the achievement of target dose by multivariable logistic regressions. Multivariable Cox regressions showed use of RASi/ARNi and beta-blockers being independently associated with lower risk of all-cause/cardiovascular death regardless of obesity, although, when considering competing risks, a lower risk of cardiovascular death with RASi/ARNi in obese versus non-obese patients was observed. RASi/ARNi were associated with lower risk of HF hospitalization in obese but not in non-obese patients, whereas beta-blockers were not associated with the risk of HF hospitalization regardless of obesity. At the competing risk analysis, RASi/ARNi use was associated with higher risk of HF hospitalization regardless of obesity. CONCLUSION: Obese patients were more likely to receive optimal treatments after adjustment for factors affecting tolerability, suggesting that perceived beyond actual tolerance issues limit GDMT implementation. RASi/ARNi and beta-blockers were associated with lower mortality regardless of obesity, with a greater association between RASi/ARNi and lower cardiovascular death in obese versus non-obese patients when considering competing risk