Two Limitations of Subcutaneous Implantable Cardioverter Defibrillator in the Same Patient Warranting Its Explant.

BACKGROUND A subcutaneous implantable cardioverter defibrillator (S-ICD) is preferred over a transvenous implantable cardioverter defibrillator (TV-ICD) in selected cases owing to a lower rate of lead-related complications such as infections and venous thrombosis. However, the S-ICD has its own limitations, including inappropriate shocks due to oversensed events, and the inability to treat ventricular tachycardia (VT) below a heart rate of 170 beats per minutes (bpm). We present a patient case which showed manifestations of both of these limitations, warranting explant of the device. CASE REPORT A 50-year-old man with a history of nonischemic cardiomyopathy and VT had a S-ICD placed at an outside facility. However, he continued to have VT despite on anti-arrhythmic drugs and required recurrent S-ICD shocks. Device interrogation showed that he was intermittently receiving appropriate shocks for slower VT (with a heart rate ranging from 150 bpm to 160 bpm) due to oversensing of T waves. However, treatment was delayed for other VT episodes owing to appropriate sensing and the patient's heart rate being below the lowest detection zone for S-ICD. Due to slower VT cycle length and frequent oversensed events, the S-ICD was ultimately replaced by a TV-ICD system. CONCLUSIONS This case report emphasizes the importance of S-ICD pre-implant vector screening and the need for paying attention to VT cycle length to prevent inappropriate device shocks and/or delayed therapies.

Association between red blood cell distribution width and mortality and severity among patients with COVID-19: A systematic review and meta-analysis.

Emerging evidence has underscored the potential usefulness of red blood cell distribution width (RDW) measurement in predicting the mortality and disease severity of COVID-19. This study aimed to assess the association of the plasma RDW levels with adverse prognosis in COVID-19 patients. A comprehensive literature search from inception to September 2020 was performed to harvest original studies reporting RDW on admission and clinical outcomes among patients hospitalized with COVID-19. RDW levels were compared between cases (patients who died or developed more severe symptoms) and controls (patients who survived or developed less severe symptoms). A total of 14,866 subjects from 10 studies were included in the meta-analysis. Higher levels of RDW were associated with adverse outcomes in COVID-19 patients (mean differences = 0.72; 95% CI = 0.47-0.97; I2 = 89.51%). Deceased patients had higher levels of RDW compared to patients who survived (mean differences = 0.93; 95% CI = 0.63-1.23; I2 = 85.58%). Severely ill COVID-19 patients showed higher levels of RDW, as opposed to patients classified to have milder symptoms (mean differences = 0.61; 95% CI = 0.28-0.94; I2 = 82.18%). Elevated RDW levels were associated with adverse outcomes in COVID-19 patients. This finding warrants further research on whether RDW could be utilized as a simple and reliable biomarker for predicting COVID-19 severity and whether RDW is mechanistically linked with COVID-19 pathophysiology.

Extended Thromboprophylaxis With Betrixaban or Rivaroxaban for Acutely Ill Hospitalized Medical Patients: Meta-Analysis of Prespecified Subgroups.

BACKGROUND: Betrixaban and rivaroxaban are the direct anticoagulants approved in the United States for extended venous thromboembolism (VTE) prophylaxis among acutely ill medical patients. The efficacy and safety in specific subgroups remain unclear. METHODS: A meta-analysis of 3 randomized trials involving extended thromboprophylaxis with betrixaban or rivaroxaban versus enoxaparin for medically ill patients was performed to compare VTE (composite of asymptomatic proximal and symptomatic deep vein thrombosis, pulmonary embolism, or VTE-related death) and major bleeding in subgroups by baseline D-dimer, age, sex, and major medical illness on hospitalization. Risk difference (RD) was computed with the Mantel-Haenszel method by fitting a fixed-effect model. Heterogeneity of treatment effect across subgroups was examined using the nominal thresholds of P < 0.05 and I2 > 75%. RESULTS: Compared with enoxaparin, extended betrixaban or rivaroxaban reduced VTE (RD = -1.51% [95% CI, -2.32% to -0.69%]; P = 0.0003) without excess major bleeding (RD = 0.12% [-0.05% to 0.29%]; P = 0.16). A significant effect modification was observed in the subgroups by D-dimer (P = 0.004) and age (P = 0.04). Patients with D-dimer >2× upper limit of normal (ULN) experienced a greater VTE reduction (RD = -2.39% [-3.57% to -1.21%]; P < 0.0001) than those with ≤2×ULN (RD = -0.26% [-1.08% to 0.56%]; P = 0.53). Similarly, patients aged ≥75 years had a greater VTE reduction (RD = -2.29% [-3.49% to -1.09%]; P = 0.0002) than those aged <75 years (RD = -0.63% [-1.70% to 0.44%]; P = 0.25). Treatment effect was consistent across the remaining subgroups. CONCLUSIONS: A more favorable efficacy and comparable safety outcome associated with extended betrixaban or rivaroxaban were observed among medical inpatients with D-dimer >2×ULN or aged ≥75 years. D-dimer and advanced age may assist in decision-making on pharmacological thromboprophylaxis for hospitalized medical patients.

COVID-19: A double threat to takotsubo cardiomyopathy and spontaneous coronary artery dissection?

Coronavirus disease 2019 (COVID-19) is an ongoing pandemic that has affected millions of individuals worldwide. Prior studies suggest that COVID-19 may be associated with an increased risk for various cardiovascular disorders, such as myocardial injury, arrhythmia, acute coronary syndrome, and venous thromboembolism. Early reports of non-COVID-19 patients have described the concurrence of takotsubo cardiomyopathy (TTC) and spontaneous coronary artery dissection (SCAD). However, the interplay between COVID-19, TTC and SCAD has not been well established. We herein propose two sets of two-hit hypotheses for the development of SCAD and TTC in the context of COVID-19. The first two-hit hypothesis explains the development of SCAD, in which TTC-associated formation of vulnerable coronary substrate serves as the first hit (predisposing factor), and COVID-19-associated inflammation and vascular disruption serves as the second hit (precipitating factor). The second two-hit hypothesis is proposed to explain the development of TTC, in which SCAD-associated formation of vulnerable myocardial substrate serves as the first hit, and COVID-19-associated sympathetic overactivity serves as the second hit. Under this conceptual framework, COVID-19 poses a double threat for the development of SCAD (among patients with underlying TTC) as well as TTC (among patients with underlying SCAD), thereby forming a reciprocal causation. This hypothesis provides a rationale for the joint assessment of TTC and SCAD in COVID-19 patients with pertinent cardiovascular manifestations.

Venous Thromboembolism among Hospitalized Patients with COVID-19 Undergoing Thromboprophylaxis: A Systematic Review and Meta-Analysis.

BACKGROUND: Preliminary evidence indicates that prophylactic-dose thromboprophylaxis may be inadequate to control the increased risk of venous thromboembolism (VTE) in patients hospitalized for coronavirus disease 2019 (COVID-19) infection. Additionally, it remains unclear whether the D-dimer measurement is useful for VTE risk stratification among COVID-19 patients. This study aimed to offer benchmark data on the incidence of VTE and to examine the difference in D-dimer levels among anticoagulated COVID-19 patients with and without VTE incident. METHODS: A comprehensive literature review of PubMed from inception to May 2020 was performed for original studies that reported the frequency of VTE and death among COVID-19 patients who received thromboprophylaxis on hospitalization. The endpoints included VTE (a composite of pulmonary embolism (PE) or deep vein thrombosis (DVT)), PE, DVT, and mortality. RESULTS: A total of 11 cohort studies were included. Among hospitalized COVID-19 patients, 23.9% (95% confidence interval (CI), 16.2% to 33.7%; I2 = 93%) developed VTE despite anticoagulation. PE and DVT were detected in 11.6% (95% CI, 7.5% to 17.5%; I2 = 92%) and 11.9% (95% CI, 6.3% to 21.3%; I2 = 93%) of patients, respectively. Patients in the intensive care unit (ICU) had a higher risk for VTE (30.4% )95% CI, 19.6% to 43.9%)) than those in the ward (13.0% (95% CI, 5.9% to 26.3%)). The mortality was estimated at 21.3% (95% CI, 17.0% to 26.4%; I2 = 53%). COVID-19 patients who developed VTE had higher D-dimer levels than those who did not develop VTE (mean difference, 2.05 µg/mL; 95% CI, 0.30 to 3.80 µg/mL; P = 0.02). CONCLUSIONS: The heightened and heterogeneous risk of VTE in COVID-19 despite prophylactic anticoagulation calls into research on the pathogenesis of thromboembolic complications and strategy of thromboprophylaxis and risk stratification. Prominent elevation of D-dimer may be associated with VTE development and can be used to identify high-risk subsets.

Vehicle Make and Model Recognition using Bag of Expressions.

Vehicle make and model recognition (VMMR) is a key task for automated vehicular surveillance (AVS) and various intelligent transport system (ITS) applications. In this paper, we propose and study the suitability of the bag of expressions (BoE) approach for VMMR-based applications. The method includes neighborhood information in addition to visual words. BoE improves the existing power of a bag of words (BOW) approach, including occlusion handling, scale invariance and view independence. The proposed approach extracts features using a combination of different keypoint detectors and a Histogram of Oriented Gradients (HOG) descriptor. An optimized dictionary of expressions is formed using visual words acquired through k-means clustering. The histogram of expressions is created by computing the occurrences of each expression in the image. For classification, multiclass linear support vector machines (SVM) are trained over the BoE-based features representation. The approach has been evaluated by applying cross-validation tests on the publicly available National Taiwan Ocean University-Make and Model Recognition (NTOU-MMR) dataset, and experimental results show that it outperforms recent approaches for VMMR. With multiclass linear SVM classification, promising average accuracy and processing speed are obtained using a combination of keypoint detectors with HOG-based BoE description, making it applicable to real-time VMMR systems.

Spontaneous coronary artery dissection managed with a conservative or revascularization approach: a meta-analysis.

BACKGROUND: The optimal treatment approach for spontaneous coronary artery dissection (SCAD) remains unclear. OBJECTIVES: The study aims to compare in-hospital and long-term clinical outcomes of SCAD patients initially managed with medical therapy (conservative approach) versus percutaneous coronary intervention or coronary artery bypass grafting (revascularization approach) based on published data. METHODS: We identified relevant studies by performing a systematic search in the Ovid MEDLINE and Embase databases. Studies with N at least 10 that report in-hospital outcomes [death, myocardial infarction (MI) and revascularization] or long-term outcomes (death, MI, revascularization, SCAD recurrence, and heart failure) were included. Risk difference between conservative and revascularization approach was estimated with the inverse variance-weighted method in a fixed-effect or random-effect model. RESULTS: A total of 22 nonrandomized, observational studies were analyzed (N = 1435). Compared with the initial revascularization approach, the conservative approach was associated with a comparable risk of in-hospital outcomes [risk difference: death, -0.61% (95% confidence interval, -2.13-0.91%), P = 0.43; MI, -0.99% (-4.65-2.67%), P = 0.60; revascularization, -3.02% (-8.79-2.75%), P = 0.31] and long-term outcomes [death, -0.06% (-2.33-2.20%), P = 0.96; MI, 0.96% (-2.35-4.27%), P = 0.57; revascularization, -3.31% (-7.63-1.02%), P = 0.13; SCAD recurrence, 3.75% (-2.05-9.55%), P = 0.21; heart failure, -0.01% (-3.13-3.11%), P = 0.99]. There was no significant heterogeneity across these studies. CONCLUSION: Pooled results suggest that SCAD patients initially managed with a conservative strategy may have similar in-hospital and long-term outcomes compared with those who received revascularization in the absence of ongoing ischemia or left main artery involvement. More data from prospective studies are warranted to validate these findings.

Spontaneous coronary artery dissection and associated myocardial bridging: Current evidence from cohort study and case reports.

Spontaneous coronary artery dissection (SCAD) is a relatively uncommon and under-diagnosed disease characterized by the dissociation of intima and media of coronary artery wall due to an intimal tear or intramural hemorrhage. The exact pathophysiology of SCAD remains elusive and may involve multiple predisposing or precipitating factors including genetic abnormalities, inherited or acquired vasculopathies, hormonal influences, inflammation, intense exercise, emotional stress, and recreational drugs. Accruing reports, including five case reports and one cohort study, have recently addressed the concurrence of SCAD and myocardial bridging (MB), an anatomic variant in which a segment of the epicardial coronary descends and traverses in the myocardium. Among the patients with coexisting MB and SCAD, the left anterior descending artery was the only artery that harbors both pathologies, with SCAD locating either within the tunneled segment or distal to the MB. No other predisposing factors or precipitating stressors for SCAD were noted. It is hypothesized that the predilection for vasospasm, impaired endothelial function, and disturbed coronary flow dynamics associated with MB bridging could collectively contribute to the development of SCAD. Future studies are warranted to explore the mechanistic implications of MB in patients with SCAD.

Effect of intensive versus standard blood pressure control on major adverse cardiac events and serious adverse events: A bivariate analysis of randomized controlled trials.

BACKGROUND: Intensive blood pressure (BP) lowering may offer protective effects against major adverse cardiac event (MACE) but is also associated with a greater risk of a serious adverse event (SAE). The risk-benefit profile of intensive versus standard BP control has not been comprehensively assessed. METHODS: Four studies were identified from a systematic literature search for randomized controlled trials comparing intensive versus standard BP lowering that reported both MACE and SAE endpoints. A previously described statistical approach was applied to characterize the efficacy-safety tradeoff of BP control. The bivariate outcome was computed to quantitatively assess the net clinical benefit (NCB) of intensive BP lowering as compared to standard treatment, with positive values indicating increased risks and negative values indicating decreased risks. RESULTS: Data from the SPRINT trial demonstrated that intensive strategy was superior in MACE but inferior in SAE, thereby eroding the NCB (bivariate outcome: 0.33% [-0.50% to 1.21%]). Intensive strategy from the SPS3 trial fulfilled non-inferiority in both MACE and SAE but did not reach a favorable NCB (-1.31% [-2.25% to 0.01%]). The ACCORD trial suggested that intensive strategy was non-inferior in MACE but inferior in SAE (-0.19% [-0.79% to 1.37%]). Results from the VALISH trial were inconclusive for SAE but suggested non-inferiority in MACE (-1.19% [-3.24% to 0.68%]). CONCLUSIONS: Compared to the standard blood pressure target, pooled data from randomized controlled trials suggest that intensive strategy did not achieve a net clinical benefit when weighing the benefit of MACE reduction against the risk of SAE under the bivariate framework. ABBREVIATIONS: Blood pressure (BP), diastolic blood pressure (DBP), major adverse cardiac event (MACE), net clinical benefit (NCB), serious adverse event (SAE), systolic blood pressure (SBP).

Dual antithrombotic plus adjunctive antiinflammatory therapy to improve cardiovascular outcome in atrial fibrillation patients with concurrent acute coronary syndrome: A triple-pathway strategy.

The concurrence of atrial fibrillation and acute coronary syndrome poses a conundrum in the antithrombotic management as intensification of anticoagulation or antiplatelet therapy inevitably comes at the price of an increased bleeding risk. Various antithrombotic combinations have been attempted to prevent the recurrent cardiovascular events, however, there has been limited success in effective risk reduction for this high risk population. Given the overarching effect of interleukin 1ß-driven inflammation on the arrhythmogenesis, thrombogenesis, and hypercoagulability, we hypothesize that the triple-pathway strategy (i.e., incorporating antiinflammatory therapy into anticoagulant and antiplatelet therapy) would grant incremental cardiovascular benefits for atrial fibrillation patients with coexisting acute coronary syndrome and stent placement.

Intercellular adhesion molecule-1 in diabetic patients with and without microalbuminuria.

BACKGROUND: Nephropathy is a major complication of type 2 diabetes mellitus (T2DM) and is heralded by the insidious development of microalbuminuria (MA). It is suggested that the serum levels of Intercellular Adhesion Molecule-1 (ICAM-1) is correlated with diabetic nephropathy. In this cross-sectional study, we evaluated serum ICAM-1 level in diabetic patients with and without MA. METHODS: A total of 187 participants were enrolled and were classified into three groups including 40 healthy controls and 2 diabetic groups with (n = 59) or without MA (n = 88). Serum levels of ICAM-1, fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein cholesterol and C-reactive protein (CRP) were measured in all three groups. Statistical analyses were performed using the SPSS software. A P-value less than 0.05 was considered statistically significant. RESULTS: Serum levels of ICAM-1 were significantly higher in diabetic patients irrespective of MA. Moreover, ICAM-1 levels in patients with MA were significantly higher than patients without MA. Patients with MA had significantly higher age and blood pressure compared to those without MA (P = 0.001). Serum levels of ICAM-1 were significantly correlated with age and HbA1c. CONCLUSIONS: Overall, serum ICAM-1 levels were significantly higher in T2DM patients with MA and it may be associated with the severity of diabetic kidney disease.

Development and evaluation of cesarean section surgical training using computer-enhanced visual learning.

BACKGROUND: Skilled performance of cesarean deliveries is essential in obstetrics and gynecology residency. A computer-enhanced visual learning module (CEVL Cesarean) was developed to teach cesarean deliveries. METHODS: An online module presented cesarean deliveries as a series of components using text, audio, video and animation. First-year residents used CEVL Cesarean and were evaluated intra-operatively by trained raters, then provided feedback about surgical performance. Clinical outcomes were collected for approximately 50 cesarean deliveries for each resident. RESULTS: From 2010 to 2011, 12 first-year residents participated in the study. About 406 unique observed cesarean deliveries were analyzed. Procedures up to each resident's 70th case were analyzed by grouping cases in 10 s (cases 1-10 and 11-20), or deciles. Resident performance significantly improved by decile [χ(2)(6) = 47.56, p < 0.001]. When examining each resident's performance, surgical skill acquisition plateaued by cases 21-30. Procedural performance, independent of resident, also improved significantly by decile [χ(2)(6) = 186.95, p < 0.001], plateauing by decile 4 (cases 31-40). Throughout the observation period, operative time decreased by 3.84 min (p = 0.006). CONCLUSIONS: Pre-clinical teaching using computer-based modules for cesarean sections is feasible to develop. Novice surgeons required at least 30 procedures before performing the procedure competently. When residents performed competently, operative time and complications decreased.