Assessment of valve regurgitation severity via contrastive learning and multi-view video integration.

Objective. This paper presents a novel approach for addressing the intricate task of diagnosing aortic valve regurgitation (AR), a valvular disease characterized by blood leakage due to incompetence of the valve closure. Conventional diagnostic techniques require detailed evaluations of multi-modal clinical data, frequently resulting in labor-intensive and time-consuming procedures that are vulnerable to varying subjective assessment of regurgitation severity.Approach. In our research, we introduce the multi-view video contrastive network, designed to leverage multiple color Doppler imaging inputs for multi-view video processing. We leverage supervised contrastive learning as a strategic approach to tackle class imbalance and enhance the effectiveness of our feature representation learning. Specifically, we introduce a contrastive learning framework to enhance representation learning within the embedding space through inter-patient and intra-patient contrastive loss terms.Main results. We conducted extensive experiments using an in-house dataset comprising 250 echocardiography video series. Our results exhibit a substantial improvement in diagnostic accuracy for AR compared to state-of-the-art methods in terms of accuracy by 9.60%, precision by 8.67%, recall by 9.01%, andF1-score by 8.92%. These results emphasize the capacity of our approach to provide a more precise and efficient method for evaluating the severity of AR.Significance. The proposed model could quickly and accurately make decisions about the severity of AR, potentially serving as a useful prescreening tool.

Optimising Preeclampsia First-Trimester Screening Using Three Parameters.

OBJECTIVE: To evaluate the performance of first-trimester preeclampsia-screening algorithm in predicting preeclampsia (PE). STUDY DESIGN: Observational study. Place and Duration of the Study: Department of Obstetrics and Gynaecology, Combined Military Hospitals (CMH) Lahore, Pakistan, between 1st January and 31st August 2022. METHODOLOGY: Data of 100 women of any parity aged 18-35 years at gestational age < 13 weeks based on the last menstrual period (LMP), was analysed. First trimester Fetal Medicine Foundation (FMF) screening algorithm for preeclampsia was used entering maternal characteristics, mean arterial pressure and uterine pulsatility index only, for risk calculation. Patients were followed up till delivery for the development of preeclampsia and fetomaternal outcomes. Clinical characteristics of women with and without preeclampsia were compared using the Chi-square and independent samples t-test. RESULTS: The mean age of patients was 29.29±4.56 years and 60% were nullipara. Seventy-eight patients were placed in the low-risk category and 22 patients were in the high-risk category according to the FMF algorithm. Preeclampsia developed in 13 patients. For a risk cut-off of 1 in 100, the FMF algorithm showed a detection rate of 38% with diagnostic accuracy of 75% and a false positive rate (FPR) of 20%. CONCLUSION: Although the performance of adapted FMF algorithm to predict preeclampsia gestational was low, it was found superior to prediction by maternal risk factors alone. Adjustment for additional factors or ethnicity-specific values may help in further improvement of detection rate. KEY WORDS: Blood pressure, Biomarkers, Biological markers, Preeclampsia, Risk assessment.

Current Status of Radionuclide Imaging of Transthyretin Cardiac Amyloidosis.

Cardiac single photon emission computed tomography using 99mTc-bone avid tracers allows for an accurate noninvasive diagnosis of transthyretin (ATTR) cardiac amyloidosis, a historically underdiagnosed disease. This imaging is recommended in select populations who demonstrate clinical and imaging features of infiltrative cardiomyopathy. It is imperative to concomitantly assess for light chain (AL) cardiac amyloidosis independent of radionuclide scintigraphy for timely management of AL amyloidosis, a deadly disease requiring urgent therapy. Clinical judgement is also key and in some select scenarios an endomyocardial biopsy may be needed even after a noninvasive evaluation.

Cluster Randomized Trial Examining the Impact of Automated Best Practice Alert on Rates of Implantable Defibrillator Therapy.

Background Implantable cardioverter-defibrillators (ICDs) are indicated in patients with left ventricular ejection fraction ≤35%, but many eligible patients do not receive this therapy. In this cluster randomized trial, we investigated the impact of a best practice alert (BPA) through the electronic health records on the rates of electrophysiology referrals, ICD implantations, and all-cause mortality in severe cardiomyopathy patients. Methods and Results Providers in the Heart and Vascular Institute (n=106) and in General Internal Medicine (n=89) were randomized to receive or not receive a BPA recommending consideration for ICD implantation. Patients belonging to the BPA and no BPA groups of providers were followed to the end points of electrophysiology referrals, ICD implantations, and all-cause mortality. Between 2013 and 2015, patients with reduced left ventricular ejection fraction were managed by 93 providers in the BPA (n=997 patients) and 102 providers in the no BPA (n=909 patients) groups. Patients in the 2 groups had comparable baseline characteristics. After a median follow-up of 36 months, 638 (33%) patients were referred to electrophysiology, 536 (27%) received an ICD, and 445 (23%) died. Patients in the BPA group were more likely to be referred to electrophysiology (hazard ratio=1.23; P=0.026), to receive ICD therapy (hazard ratio=1.35; P=0.006), and exhibited a trend towards slightly lower mortality (hazard ratio=0.85; P=0.091). Conclusions Delivering a BPA through the electronic health record recommending to providers consideration of ICD implantation when the left ventricular ejection fraction is ≤35% improves the rates of electrophysiology referrals and ICD therapy in patients with severe left ventricular dysfunction.

Transcatheter closure of patent foramen ovale following cryptogenic stroke: An updated meta-analysis of randomized controlled trials.

BACKGROUND: Transcatheter closure of patent foramen ovale (PFO) after cryptogenic stroke has long been a contentious issue. Herein, we pool aggregate data examining safety and efficacy of transcatheter closure of PFO compared with medical therapy following initial cryptogenic stroke. METHODS: We searched for randomized clinical trials (RCT) that compared device closure with medical management and reported on subsequent stroke and adverse events. Stroke was considered as the primary efficacy endpoint, whereas bleeding and atrial fibrillation were considered primary safety endpoints. Data were pooled by the random effects model and I2 was used to assess heterogeneity. RESULTS: A total of 5 RCT investigating 3630 patients met inclusion criteria. Pooled analysis revealed that device closure compared to medical management was associated with a significant reduction in stroke (RR=0.3, 95% CI=0.02-0.57). There was, however, a significant increase in atrial arrhythmias with device therapy (RR=4.8, 95% CI=2.2-10.7). We found no increase in bleeding (RR=0.80, 95% CI=0.5-1.4), death (RR=0.76, 95% CI=0.3-1.99) or "any adverse events" (RR=1.02, 95% CI=0.85-1.23) with device therapy. Sub-group analysis revealed that device closure significantly reduced the incidence of the composite primary endpoint among patients who had moderate to large shunt sizes (RR=0.22, 95% CI=0.02-0.42). CONCLUSIONS: Transcatheter closure is associated with a significant reduction in the risk of stroke compared to medical management at the expense of an increased risk of atrial arrhythmias.

Predictors and outcomes of lead extraction requiring a bailout femoral approach: Data from 2 high-volume centers.

BACKGROUND: Lead extraction (LE) infrequently requires the use of the "bailout" femoral approach. Predictors and outcomes of femoral extraction are not well characterized. OBJECTIVE: The aim of this study was to determine the predictors of need for femoral LE and its outcomes. METHODS: Consecutive patients who underwent LE at our centers were identified. Baseline demographic characteristics, procedural outcomes, and clinical outcomes were ascertained by medical record review. Patients were stratified into 2 groups on the basis of the need for femoral extraction. RESULTS: A total of 1080 patients underwent LE, of whom 50 (4.63%) required femoral extraction. Patients requiring femoral extraction were more likely to have leads with longer dwell time (9.5 ± 6.0 years vs 5.7 ± 4.3 years; P < .001), to have more leads extracted per procedure (2.0 ± 1.0 vs 1.7 ± 0.9; P = .003), and to have infection as an indication for extraction (72% vs 37.2%; P < .001). Procedural and clinical success was lower in the femoral extraction group than in the nonfemoral group (58% and 76% vs 94.7% and 97.9 %, respectively; P < .001). Major periprocedural complications (0% vs 1.3%; P = 1.0) and periprocedural mortality (0% vs 0.8%; P = 1.0) were similar between the 2 groups. CONCLUSION: In this study, femoral extraction was needed in ~5% of LEs. Longer lead dwell time, higher number of leads extracted per procedure, and the presence of infection predicted the need for femoral extraction. Procedural success of femoral extraction was low, highlighting the fact that this approach is mostly used as a bailout strategy and thus selects for more challenging cases.

Is it time to replace propranolol with carvedilol for portal hypertension?

Beta-adrenergic receptor antagonists (ß-blockers) have been well established for use in portal hypertension for more than three decades. Different Non-selective ß-blockers like propranolol, nadolol, timolol, atenolol, metoprolol and carvedilol have been in clinical practice in patients with cirrhosis. Carvedilol has proven 2-4 times more potent than propranolol as a beta-receptor blocker in trials conducted testing its efficacy for heart failure. Whether the same effect extends to its potency in the reduction of portal venous pressures is a topic of on-going debate. The aim of this review is to compare the hemodynamic and clinical effects of carvedilol with propranolol, and attempt assess whether carvedilol can be used instead of propranolol in patients with cirrhosis. Carvedilol is a promising agent among the beta blockers of recent time that has shown significant effects in portal hypertension hemodynamics. It has also demonstrated an effective profile in its clinical application specifically for the prevention of variceal bleeding. Carvedilol has more potent desired physiological effects when compared to Propranolol. However, it is uncertain at the present juncture whether the improvement in hemodynamics also translates into a decreased rate of disease progression and complications when compared to propranolol. Currently Carvedilol shows promise as a therapy for portal hypertension but more clinical trials need to be carried out before we can consider it as a superior option and a replacement for propranolol.

Vivax malaria and chloroquine resistance: a neglected disease as an emerging threat.

In Pakistan, Plasmodium vivax contributes to major malaria burden. In this case, a pregnant woman presented with P. vivax infection and which was not cleared by chloroquine, despite adequate treatment. This is probably the first confirmed case of chloroquine-resistant vivax from Pakistan, where severe malaria due to P. vivax is already an emerging problem.

Combination approaches to potentiate immune response after photodynamic therapy for cancer.

Photodynamic therapy (PDT) has been used as a cancer therapy for forty years but has not advanced to a mainstream cancer treatment. Although it has been shown to be an efficient way to destroy local tumors by a combination of non-toxic dyes and harmless visible light, it is its additional effects in mediating the stimulation of the host immune system that gives PDT great potential to become more widely used. Although the stimulation of tumor-specific cytotoxic T-cells that can destroy distant tumor deposits after PDT has been reported in some animal models, it remains the exception rather than the rule. This realization has prompted several investigators to test various combination approaches that could potentiate the immune recognition of tumor antigens that have been released after PDT. This review will cover these combination approaches using immunostimulants including various microbial preparations that activate Toll-like receptors and other receptors for pathogen-associated molecular patterns, cytokines growth factors, and approaches that target regulatory T-cells. We believe that by understanding the methods employed by tumors to evade immune response and neutralizing them, more precise ways of potentiating PDT-induced immunity can be devised.