Design of load-aware resource allocation for heterogeneous fog computing systems.

The execution of delay-aware applications can be effectively handled by various computing paradigms, including the fog computing, edge computing, and cloudlets. Cloud computing offers services in a centralized way through a cloud server. On the contrary, the fog computing paradigm offers services in a dispersed manner providing services and computational facilities near the end devices. Due to the distributed provision of resources by the fog paradigm, this architecture is suitable for large-scale implementation of applications. Furthermore, fog computing offers a reduction in delay and network load as compared to cloud architecture. Resource distribution and load balancing are always important tasks in deploying efficient systems. In this research, we have proposed heuristic-based approach that achieves a reduction in network consumption and delays by efficiently utilizing fog resources according to the load generated by the clusters of edge nodes. The proposed algorithm considers the magnitude of data produced at the edge clusters while allocating the fog resources. The results of the evaluations performed on different scales confirm the efficacy of the proposed approach in achieving optimal performance.

Coronary flow capacity and survival prediction after revascularization: physiological basis and clinical implications.

BACKGROUND AND AIMS: Coronary flow capacity (CFC) is associated with an observed 10-year survival probability for individual patients before and after actual revascularization for comparison to virtual hypothetical ideal complete revascularization. METHODS: Stress myocardial perfusion (mL/min/g) and coronary flow reserve (CFR) per pixel were quantified in 6979 coronary artery disease (CAD) subjects using Rb-82 positron emission tomography (PET) for CFC maps of artery-specific size-severity abnormalities expressed as percent left ventricle with prospective follow-up to define survival probability per-decade as fraction of 1.0. RESULTS: Severely reduced CFC in 6979 subjects predicted low survival probability that improved by 42% after revascularization compared with no revascularization for comparable severity (P = .0015). For 283 pre-and-post-procedure PET pairs, severely reduced regional CFC-associated survival probability improved heterogeneously after revascularization (P < .001), more so after bypass surgery than percutaneous coronary interventions (P < .001) but normalized in only 5.7%; non-severe baseline CFC or survival probability did not improve compared with severe CFC (P = .00001). Observed CFC-associated survival probability after actual revascularization was lower than virtual ideal hypothetical complete post-revascularization survival probability due to residual CAD or failed revascularization (P < .001) unrelated to gender or microvascular dysfunction. Severely reduced CFC in 2552 post-revascularization subjects associated with low survival probability also improved after repeat revascularization compared with no repeat procedures (P = .025). CONCLUSIONS: Severely reduced CFC and associated observed survival probability improved after first and repeat revascularization compared with no revascularization for comparable CFC severity. Non-severe CFC showed no benefit. Discordance between observed actual and virtual hypothetical post-revascularization survival probability revealed residual CAD or failed revascularization.

Percutaneous revascularization for the treatment of refractory digital ischemia in systemic sclerosis.

Objective: The objective of this study is to explore the role of adjunctive percutaneous revascularization of the hand in the management of patients with systemic sclerosis-associated refractory digital ischemia. Methods: We present our initial experience of using percutaneous upper extremity interventions to treat patients with systemic sclerosis and symptomatic Raynaud's phenomenon who presented with either refractory digital ischemia or non-healing ulcers. We discuss patient characteristics, procedural findings, and short-term clinical outcomes of these interventions. Results: We performed 14 interventions in 6 patients with non-healing digital ulcers or refractory ischemia secondary to systemic sclerosis. Angioplasty was performed at or below the wrist in conjunction with intravenous prostaglandin therapy, started prior to or immediately after the revascularization procedure. All patients experienced symptomatic relief and demonstrated accelerated wound healing. Two patients required an additional procedure to treat recurrent ischemia (without new ulceration) in the treated digit. Three of the patients underwent multiple procedures during the study period to treat new ischemic lesions or Raynaud's phenomenon symptoms, highlighting the progressive nature of the vascular occlusions in systemic sclerosis. There were no adverse events related to the interventions. Conclusions: Our retrospective analysis suggests that percutaneous revascularization in combination with vasodilator therapy in systemic sclerosis-associated digital ischemia is safe and can facilitate the healing of long-standing ulcers. Its role in the management of refractory digital ischemia in patients with systemic sclerosis should be explored further.

Total Percutaneous Revascularization of the Hand to Treat Refractory Digital Ischemia in Advanced Systemic Sclerosis.

We present the case of a young woman with systemic sclerosis (SSc) and refractory digital ulceration who was successfully treated with percutaneous revascularization of chronically occluded ulnar and radial arteries. To our knowledge, this is the first detailed report of limb salvage in SSc-induced hand ischemia in which contemporary endovascular techniques were used. (Level of Difficulty: Advanced.).

In-Hospital Outcomes and Trends of Endovascular Intervention vs Surgical Revascularization in Octogenarians With Peripheral Artery Disease.

It is unknown whether endovascular intervention (EVI) is associated with superior outcomes when compared with surgical revascularization in octogenarian. National Inpatient Sample (NIS) database was used to compare the outcomes of limb revascularization in octogenarians who had surgical revascularization versus EVI. The NIS database's information on PAD patients ≥80-year-old who underwent limb revascularization between 2002 and 2014 included 394,504 octogenarian patients, of which 184,926 underwent surgical revascularization (46.9%) and 209,578 underwent EVI (53.1%). Multivariate analysis was performed to examine in-hospital outcomes. Trend over time in limb revascularization utilization was examined using Cochrane-Armitage test. EVI group had lower odds of in-hospital mortality (adjusted odds ratio [aOR]: 0.61 [95% CI: 0.58 to 0.63], myocardial infarction (aOR: 0.84 [95% CI: 0.81 to 0.87]), stroke (aOR: 0.93 [95% CI: 0.89 to 0.96]), acute kidney injury (aOR: 0.79 [95% CI: 0.77 to 0.81]), and limb amputation (aOR: 0.77 [95% CI: 0.74 to 0.79]) compared with surgical group (p < 0.001 for all). EVI group had higher risk of bleeding (aOR: 1.20 [95% CI: 1.18 to 1.23]) and vascular complications (3.2% vs 2.7%, aOR: 1.25 [95% CI: 1.19 to 1.30]) compared with surgical group (p < 0.001 for all). Within study period, EVI utilization increased in octogenarian patients from 2.6% to 8.9% (ptrend < 0.001); whereas use of surgical revascularization decreased from 11.6% to 5.2% (ptrend < 0.001). In conclusion, the utilization of EVI in octogenarians is increasing, and associated with lower risk of in-hospital mortality and adverse cardiovascular and limb outcomes as compared with surgical revascularization.

Decreasing Rates of Acute Kidney Injury After Percutaneous Coronary Interventions Through Education and Standardized Order Sets in a Large Tertiary Teaching Center.

Acute kidney injury (AKI) is a common complication of percutaneous coronary interventions (PCI), and it is associated with increased morbidity, mortality, and healthcare costs. Post-PCI AKI is a major quality outcome measured by the National Cardiovascular Data Registry for hospitals that perform PCI. We report the experience of a large, tertiary center with high standardized, post-PCI AKI rates in which we implemented multilevel interventions that included: (1) a multidisciplinary education module for all personnel involved in care of patients undergoing cardiac angiography, (2) a standardized electronic medical record based preprocedure hydration protocol order set for patients undergoing cardiac angiography, and (3) a hydration task list to be completed by the care team the evening before the procedure or prior to admission. All this resulted in a constant decrease of the post-PCI AKI rates in remarkable magnitude, significantly stronger than the national tendency, demonstrating a center-specific behavior.

Association of Risk of Dementia With Direct Oral Anticoagulants Versus Warfarin Use in Patients With Non-valvular Atrial Fibrillation: A Systematic Review and Meta-analysis.

ABSTRACT: Atrial fibrillation (AF) is associated with an increased risk of dementia. Studies have shown the beneficial effects of anticoagulants in preventing dementia in this population. However, evidence around the use of direct oral anticoagulants (DOACs) versus warfarin in AF-related dementia prevention remains sparse. This systematic review and meta-analysis aimed to evaluate the use of DOACs versus warfarin in dementia prevention in this population. MEDLINE, EMBASE, PsycINFO, and the CENTRAL databases were systematically searched from its inception until May 2020. Nine studies (n = 611,069) were included for quantitative meta-analysis. DOACs use was associated with a lower risk of composite dementia outcomes compared with warfarin use [odds ratio (OR) 0.56, 95% confidence interval (CI) 0.34-0.94, P = 0.03]. No significant difference was found in subtypes of dementia (vascular dementia, Alzheimer's disease, and cognitive disorder) between both groups. No significant difference in the risk of composite dementia outcomes between the dabigatran and warfarin groups (OR 0.97, 95% CI 0.88-1.08, P = 0.61). Apixaban (OR 0.58, 95% CI 0.50-0.67, P < 0.00001) and rivaroxaban (OR 0.67, 95% CI 0.61-0.75, P < 0.00001) use were both associated with a significantly lower risk of composite dementia outcomes compared with warfarin use. Findings need to be interpreted with caution because of low certainty of evidence. In conclusion, this systematic review and meta-analysis of 9 comparative studies demonstrated the superiority of DOACs over warfarin in prevention of dementia in AF. Future prospective trials with adequate follow-up period are warranted to ascertain its causal relationship.

Comparison of In-Hospital Outcomes in Patients Having Limb-Revascularization With Versus Without Atrial Fibrillation.

The impact of atrial fibrillation (AF) on clinical outcomes among patients with peripheral artery disease (PAD) who undergo limb revascularization procedures is not well understood. We aim to compare in-hospital outcomes for patients with and without AF who underwent limb revascularization. We identified patients with PAD aged ≥18 years that underwent limb revascularization using endovascular or surgical approaches in the National Inpatient Sample between 2002 and 2014. Multivariate logistic regression analysis was performed to examine in-hospital outcomes. A total of 2,283,568 patients underwent limb revascularization during the study duration and 294,469 (12.9%) had AF. Patients with AF were older (mean age 76.1 ± 10.0 years), more likely to be women and white, compared with non-AF group. Among patients who had surgical revascularization, AF was associated with a higher rates of in-hospital mortality (6.4% vs 2.5%, adjusted odds ratio [aOR]: 1.09 [95% confidence interval {CI}: 1.05 to 1.12]) and major amputation (5.2% vs 3.8%, aOR: 1.05 [95% CI: 1.02 to 1.08]), compared with non-AF group. Among patients who had endovascular intervention (EVI), AF was associated with a higher rates of in-hospital mortality (3.8% vs 1.6%, aOR: 1.29 [95% CI: 1.24 to 1.33]) and major amputation (5.2% vs 3.9%, aOR: 1.07 [95% CI: 1.04 to 1.10]), compared with non-AF group. Within study period, EVI utilization increased in patients with and without AF (Ptrend <0.001); whereas, surgical revascularization utilization decreased in patients with and without AF (Ptrend <0.001). In conclusion, among patients with PAD who undergo limb revascularization, AF appears to be associated with poor in-hospital outcomes.

The cardiac arrest survival score: A predictive algorithm for in-hospital mortality after out-of-hospital cardiac arrest.

BACKGROUND: Out-of-hospital cardiac arrest (OHCA) is associated with high mortality. Current methods for predicting mortality post-arrest require data unavailable at the time of initial medical contact. We created and validated a risk prediction model for patients experiencing OHCA who achieved return of spontaneous circulation (ROSC) which relies only on objective information routinely obtained at first medical contact. METHODS: We performed a retrospective evaluation of 14,892 OHCA patients in a large metropolitan cardiac arrest registry, of which 3952 patients had usable data. This population was divided into a derivation cohort (n = 2,635) and a verification cohort (n = 1,317) in a 2:1 ratio. Backward stepwise logistic regression was used to identify baseline factors independently associated with death after sustained ROSC in the derivation cohort. The cardiac arrest survival score (CASS) was created from the model and its association with in-hospital mortality was examined in both the derivation and verification cohorts. RESULTS: Baseline characteristics of the derivation and verification cohorts were not different. The final CASS model included age >75 years (odds ratio [OR] = 1.61, confidence interval [CI][1.30-1.99], p < 0.001), unwitnessed arrest (OR = 1.95, CI[1.58-2.40], p < 0.001), home arrest (OR = 1.28, CI[1.07-1.53], p = 0.008), absence of bystander CPR (OR = 1.35, CI[1.12-1.64], p = 0.003), and non-shockable initial rhythm (OR = 3.81, CI[3.19-4.56], p < 0.001). The area under the curve for the model derivation and model verification cohorts were 0.7172 and 0.7081, respectively. CONCLUSION: CASS accurately predicts mortality in OHCA patients. The model uses only binary, objective clinical data routinely obtained at first medical contact. Early risk stratification may allow identification of more patients in whom timely and aggressive invasive management may improve outcomes.

Outcomes of Acute Myocardial Infarction in Patients with Influenza and Other Viral Respiratory Infections.

BACKGROUND: Acute influenza infection can trigger acute myocardial infarction, however, outcome of patients with acute myocardial infarction during influenza infection is largely unknown. METHODS: Patients ≥18 years old with ST-elevation and non-ST-elevation myocardial infarction during January 2013-December 2014 were identified using the National Inpatient Sample. The clinical outcomes were compared among patients who had no respiratory infection to the ones with influenza and other viral respiratory infections using propensity score-matched analysis. RESULTS: Of 1,884,985 admissions for acute myocardial infarction, acute influenza and other viral infections were diagnosed in 9,885 and 11,485 patients, respectively, accounting for 1.1% of patients. Acute myocardial infarction patients with concomitant influenza infection had a worse outcome than those with acute myocardial infarction alone, in terms of in-hospital case fatality rate, development of shock, acute respiratory failure, acute kidney injury, and higher rate of blood transfusion after propensity scores. The length of stay is also significantly longer in influenza patients with acute myocardial infarction, compared with patients with acute myocardial infarction alone. However, patients who developed acute myocardial infarction during other viral respiratory infection have a higher rate of acute respiratory failure but overall lower mortality rate, and are less likely to develop shock or require blood transfusion after propensity match. Despite presenting with acute myocardial infarction, less than one-fourth of patients with concomitant influenza infection underwent coronary angiography, but more than half (51.4%) required revascularization. CONCLUSION: Influenza infection is associated with worse outcomes in acute myocardial infarction patients, and patients were less likely to receive further evaluation with invasive coronary angiography.

Fulminant Vascular and Cardiac Toxicity Associated with Tyrosine Kinase Inhibitor Sorafenib.

The use of vascular endothelial growth factor inhibitors such as sorafenib is limited by a risk of severe cardiovascular toxicity. A 28-year-old man with acute myeloid leukemia treated with prednisone, tacrolimus, and sorafenib following stem cell transplantation presented with severe bilateral lower extremity claudication. The patient was discharged against medical advice prior to finalizing a cardiovascular evaluation, but returned 1 week later with signs suggestive of septic shock. Laboratory tests revealed troponin I of 12.63 ng/mL, BNP of 1690 pg/mL, and negative infectious workup. Electrocardiogram showed sinus tachycardia and new pathologic Q waves in the anterior leads. Coronary angiography revealed severe multivessel coronary artery disease. Peripheral angiography revealed severely diseased left anterior and posterior tibial arteries, tibioperoneal trunk, and peroneal artery, and subtotal occlusion of the right posterior tibial artery. Multiple coronary and peripheral drug-eluting stents were implanted. An intra-aortic balloon pump was placed. Cardiac magnetic resonance imaging revealed chronic left ventricular infarction with some viability, 17% ejection fraction, and left ventricular mural thrombi. The patient opted for medical management. Persistent symptoms 9 months later led to repeat angiography, showing total occlusion of the second obtuse marginal artery due to in-stent restenosis with proximal stent fracture, and chronic total occlusion of the right internal iliac artery extending to the pudendal branch. Cardiac positron emission tomography/computed tomography viability study demonstrated viable myocardium, deeming revascularization appropriate. Symptom resolution was obtained with no recurrences. Sorafenib-associated vasculopathy may follow a fulminant course. Multimodality cardiovascular imaging is essential for optimal management.

Reversed Pulsus Paradoxus in Right Ventricular Failure.

Reversed pulsus paradoxus was first described in 1973 as a rise in peak systolic pressure on inspiration in patients with idiopathic hypertrophic subaortic stenosis or isorhythmic ventricular rhythm and in patients with left ventricular systolic dysfunction on positive pressure ventilation. Positive pressure ventilation, for example, may impel blood from the pulmonary capillaries and venules into the left atrium. This may increase left ventricular preload and accelerate ventricular emptying, which in turn may cause the systolic arterial pressure to rise during inspiration. We observed this phenomenon in a patient with a large pericardial effusion, right ventricular failure, and pulmonary arterial hypertension, and we noted the lack of echocardiographic features of tamponade in the presence of right ventricular hypertrophy and pulmonary hypertension. This case report discusses the subsequent occurrence of acute congestive heart failure after pericardiocentesis.

The Society of Thoracic Surgery Risk Score as a Predictor of 30-Day Mortality in Transcatheter vs Surgical Aortic Valve Replacement: A Single-Center Experience and its Implications for the Development of a TAVR Risk-Prediction Model.

BACKGROUND: The Society of Thoracic Surgery (STS) risk score serves as an important determinant of eligibility for transcatheter aortic valve replacement (TAVR). The STS score's validity for predicting TAVR mortality, however, is incompletely understood. This study compares the STS score's discriminatory power for TAVR mortality as compared with surgical aortic valve replacement (SAVR) mortality. METHODS: A retrospective analysis of STS score and 30-day mortality for TAVR patients (n = 426) and SAVR patients (n = 297) at a single institution was performed. The performance of the STS score was evaluated from the standpoint of discriminatory power. The predictive ability of STS for 30-day mortality was detected by generation of receiver operator characteristic (ROC) curves. RESULTS: The STS score possesses predictive ability for 30-day SAVR mortality with an area under the ROC curve of 0.791 (95% confidence interval [CI], 0.690-0.893). The STS score also possesses predictive ability for 30-day TAVR mortality with an area under the ROC curve of 0.674 (95% CI, 0.541-0.807). When stratifying TAVR by access route, the STS score for transfemoral TAVR provides an area under the ROC curve of 0.789 (95% CI, 0.569-1.000). There is not a statistically significant difference in predictive ability between SAVR and TAVR. CONCLUSION: The STS score possesses predictive value for 30-day mortality in both SAVR and TAVR. Although not designed for TAVR, the STS score may provide some insight into TAVR mortality, and therefore serves as an appropriate model for efforts to develop a TAVR-specific risk prediction instrument.