Pharmacotherapy and revascularization strategies of peripheral artery disease

The global epidemiological transition of atherosclerotic vascular diseases is witnessing a rapid redistribution of its burden, shifting from high-income to low- and middle-income countries. With a wide clinical spectrum, spanning from intermittent claudication to more complex critical limb threatening ischemia, nonhealing ulcers, gangrene as well as acute limb ischemia, peripheral artery disease is often faced with the challenges of under-diagnosis and under-treatment despite its high prevalence. The management of peripheral arterial disease in patients with multiple comorbidities presents a formidable challenge and remains a pressing global health concern. In this review, we aim to provide an in-depth overview of the pathophysiology of peripheral artery disease and explore evidence-based management strategies encompassing pharmacological, lifestyle, interventional, and surgical approaches. By addressing these challenges, the review contributes to a better understanding of the evolving landscape of peripheral artery disease, offering insights into effective and holistic management strategies.

AABB recommends restrictive RBC transfusions for hospitalized adults and children

SOURCE CITATION

Carson JL, Stanworth SJ, Guyatt G, et al. Red blood cell transfusion: 2023 AABB international guidelines. JAMA. 2023;330:1892-1902. 37824153.

Direct Oral Anticoagulants: An Overview of Indications, Pharmacokinetics, Comorbidities, and Perioperative Management

Direct oral anticoagulants (DOACs) have catalyzed a significant paradigm shift in the landscape of anticoagulant therapy, emerging as pivotal agents for the prevention of stroke in atrial fibrillation and venous thromboembolism. Although the absolute advantages of DOACs over vitamin K antagonists (VKAs) may appear modest, clinical guidelines advocate for their preference across various indications, attributing this endorsement to their ease of administration and heightened safety. DOACs find application in preventing and treating diverse cardiovascular conditions. With the progressive expansion of DOAC utility, clinicians encounter intricate decisions concerning the selection of appropriate agents, determination of optimal treatment duration, and utilization within specialized patient subgroups. Extensive evidence has substantiated the noninferiority or superiority of DOACs compared with VKAs in both prophylaxis and treatment of thromboembolic events. Notably, routine monitoring to evaluate treatment efficacy is not mandated for DOACs; however, they exhibit interactions with co-administered drugs and exert influence on functional coagulation assessments. This review aims to synthesize existing literature, encompassing the delineation of appropriate clinical indications, tailored employment in patients with specific concurrent conditions, needs in monitoring parameters, seamless transitions during shifts between anticoagulant regimens, and a glimpse into forthcoming perspectives in this evolving field.

Genetic and Molecular Mechanisms in Brugada Syndrome

Brugada syndrome is a rare hereditary arrhythmia disorder characterized by a distinctive electrocardiogram pattern and an elevated risk of ventricular arrhythmias and sudden cardiac death in young adults. Despite recent advances, it remains a complex condition, encompassing mechanisms, genetics, diagnosis, arrhythmia risk stratification, and management. The underlying electrophysiological mechanism of Brugada syndrome requires further investigation, with current theories focusing on abnormalities in repolarization, depolarization, and current-load match. The genetic basis of the syndrome is strong, with mutations found in genes encoding subunits of cardiac sodium, potassium, and calcium channels, as well as genes involved in channel trafficking and regulation. While the initial discovery of mutations in the SCN5A gene provided valuable insights, Brugada syndrome is now recognized as a multifactorial disease influenced by several loci and environmental factors, challenging the traditional autosomal dominant inheritance model. This comprehensive review aims to provide a current understanding of Brugada syndrome, focusing on its pathophysiology, genetic mechanisms, and novel models of risk stratification. Advancements in these areas hold the potential to facilitate earlier diagnosis, improve risk assessments, and enable more targeted therapeutic interventions.

Experimental drugs for supraventricular tachycardia: an analysis of early phase clinical trials

INTRODUCTION

Supraventricular tachycardias (SVT) are a diverse group of commonly encountered arrhythmias arising at or above the atrioventricular (AV) node. Conventional anti-arrhythmic medications are restricted by extensive side-effect profiles and limited efficacy. Catheter ablation has emerged as a first-line therapy for many arrhythmias but is not a suitable option for all patients. This has prompted the exploration of novel pharmacological approaches targeting specific molecular mechanisms of SVT.

AREAS COVERED

This review article aims to summarize recent advancements in pharmacological therapeutics for SVT and their clinical implications. The understanding of molecular mechanisms underlying these arrhythmias, particularly atrial fibrillation, has opened up new possibilities for targeted interventions. Beyond the manipulation of ion channels and membrane potentials, pharmacotherapy now focuses on upstream targets such as inflammation, oxidative stress, and structural remodeling. This review strives to provide a comprehensive overview of recent advancements in pharmacological therapeutics directed at the management of SVT. We begin by providing a brief summary of the mechanisms and management of commonly encountered SVT before delving into individual agents, which in turn are stratified based on their molecular treatment targets.

EXPERT OPINION

The evolving landscape of pharmacologic therapy offers hope for more personalized and tailored interventions in the management of SVT.

Prognostic significance of incorporating exercise tissue doppler mitral annular early diastolic velocity in exercise diastolic dysfunction assessment

BACKGROUND

The existing algorithm for defining exercise-induced diastolic dysfunction incorporates resting e' velocity as a surrogate of myocardial relaxation. The additive prognostic value of incorporating post-exercise e' velocity in definition of exercise-induced diastolic dysfunction is poorly studied.

AIM

To define the additive prognostic value of post-exercise e' septal velocity in the assessment of exercise-induced diastolic dysfunction compared to the traditional approach.

METHODS

This retrospective study included 1409 patients undergoing exercise treadmill echocardiography with available full set of diastolic variables. Doppler measures of diastolic function included resting septal e' velocity, post-exercise septal e' velocity, post-exercise E/e' ratio, and post-exercise tricuspid regurgitant jet velocity. Approaches incorporating resting septal e' velocity and post-exercise septal e' velocity were compared in defining exercise-induced diastolic dysfunction, and for association with adverse cardiovascular outcomes.

RESULTS

The mean age of study subjects was 56.3 ± 16.5 years and 791 (56%) patients were women. A total of 524 patients had disagreement between resting and post exercise septal e' velocities, and these values showed only weak agreement (kappa statistics: .28, P = .02). All categories of the traditional exercise-induced DD approach incorporating resting septal e' velocity witnessed reclassification when exercise septal e' velocity was used. When both approaches were compared, increased event rates were only evident when both approaches agreed on exercise-induced diastolic dysfunction (HR: 1.92, P < .001, 95% CI: 1.37-2.69). This association persisted after multivariable adjustment and propensity score matching for covariates.

CONCLUSION

Incorporation of post-exercise e' velocity into the set of variables defining exercise-induced diastolic dysfunction can improve the prognostic utility of diastolic function assessment.

Drug Reaction With Eosinophilia and Systemic Symptoms-Associated Perimyocarditis After Initiation of Anti-tuberculosis Therapy: A Case Report

A 34-year-old female who was recently placed on anti-tuberculosis medication with rifampin, isoniazid, pyrazinamide, and levofloxacin therapy for suspected tuberculosis reinfection presented with subjective fevers, rash, and generalized fatigue. Labs showed signs of end-organ damage with eosinophilia and leukocytosis. One day later, the patient became hypotensive with a worsening fever, and an electrocardiogram showed new diffuse ST segment elevations with an elevated troponin. An echocardiogram revealed a reduction in ejection fraction with diffuse hypokinesis, and cardiac magnetic resonance imaging (MRI) showed circumferential myocardial edema with subepicardial and pericardial inflammation. Prompt diagnosis of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome using the European Registry of Severe Cutaneous Adverse Reaction (RegiSCAR) criteria and discontinuation of therapy was initiated. Due to the hemodynamic instability of the patient, the patient was started on systemic corticosteroids and cyclosporine, with the improvement of her symptoms and rash. A skin biopsy was performed, which revealed perivascular lymphocytic dermatitis, consistent with DRESS syndrome. As the patient's ejection fraction improved spontaneously with corticosteroids, the patient was discharged with oral corticosteroids, and a repeat echocardiogram showed full recovery of ejection fraction. Perimyocarditis is a rare complication of DRESS syndrome that is associated with degranulation and the release of cytotoxic agents into myocardial cells. Early discontinuation of offending agents and initiation of corticosteroids are essential to rapid recovery of ejection fraction and improved clinical outcomes. Multimodality imaging, including MRI, should be used to confirm perimyocardial involvement and guide the necessity for mechanical support or transplant. Further research should be on the mortality of DRESS syndrome with and without myocardial involvement, with an increased emphasis on cardiac evaluation in DRESS syndrome.

Postural Orthostatic Tachycardia Syndrome in COVID-19: A Contemporary Review of Mechanisms, Clinical Course and Management

The long-term implications of COVID-19 have garnered increasing interest in recent months, with Long-COVID impacting over 65 million individuals worldwide. Postural orthostatic tachycardia syndrome (POTS) has emerged as an important component of the Long-COVID umbrella, estimated to affect between 2 and 14% of survivors. POTS remains very challenging to diagnose and manage - this review aims to provide a brief overview of POTS as a whole and goes on to summarize the available literature pertaining to POTS in the setting of COVID-19. We provide a review of available clinical reports, outline proposed pathophysiological mechanisms and end with a brief note on management considerations.

Diastolic stress echocardiography in patients with normal resting diastolic function: prognostic utility in presence and absence of myocardial ischemia

Background

Abnormal diastolic response to exercise is reportedly associated with worse cardiovascular events. However, this has not been well studied in patients with normal diastolic function at rest.

Purpose

We sought to study diastolic response to exercise in patients referred for exercise stress echocardiography (ExE) and to explore its association with adverse outcomes in the presence and absence of exercise-induced myocardial ischemia.

Methods

In a retrospective study, patients referred for ExE to assess myocardial ischemia between April 2017 and December 2018 were enrolled. Patients were included if they had guideline-defined normal diastolic function at rest and availability of a full set of post exercise diastolic variables (post exercise tissue Doppler derived septal mitral annular early diastolic velocity (e'), ratio of pulsed Doppler derived mitral forward flow early diastolic velocity (E) over e' (E/e') and continuous wave Doppler derived maximum tricuspid regurgitation velocity (TRV)). The patients were followed for a median of 3.4 years for the occurrence of composite death, acute coronary syndrome, cardiac hospitalization, and need of follow-up ischemia testing. Abnormal exercise diastolic variables were defined as e' &lt;7 cm/s, E/e' &gt;15, and TRV &gt;2.8 m/s.

Results

We studied 492 patients [age: 55.7±12.9 year, 268 (54%) women, EF: 61±5.8%]. Mean achieved metabolic equivalents of tasks (METs) was 9.7±3.1, and a total of 49 (10%) patients had evidence of exercise-induced ischemia. At rest, mean left atrial volume index was 25.4±12 ml, e' was 8±2 cm/s, E/e' was 9.5±2.4, and TRV was 2.1±0.44 m/s. Post exercise e' was 10±3 cm/s [&lt;7cm/s in 63 (13%)], E/e' was 11.1±3.9 [&gt;15 in 95 (19%)], and TRV was 2.37±0.68 m/s [&gt;2.8 m/s in 152 (31%)]. Ischemic ExE was found to be strongly associated with the outcome (HR: 4.46, 95% CI: 2.8 to 7.1, p&lt;0.001). In addition, all diastolic variables predicted the outcome in isolation if they were abnormal (e': 2.28, 95% CI: 1.4 to 3.7, p=0.001, E/e': 1.81; 95% CI: 1.15 to 2.84, p=0.01; TRV: 1.58, 95% CI: 1.17 to 2.13, p=0.003). When combined, however, association with the outcome was seen only when 2 or 3 of these variables were abnormal simultaneously (Figure 1A). When patients were stratified by ischemia and abnormal diastolic variables (figure 1B), patients with 2 or 3 abnormal variables were more likely to experience the outcome compared to patients with 0 or 1 abnormal variables in both absence of ischemia (p&lt;0.001) and presence of ischemia (p=0.016). The stratified groups were different in their clinical and exercise profiles, with worse profiles in patients with both ischemia and 2 or 3 abnormal variables, and best profiles in patients with no ischemia and 0 or 1 abnormal variables.

Conclusions

In patients referred for ExE to assess ischemia with normal baseline diastolic function, exercise can unmask abnormal diastolic properties and stratify patients' risk regardless of the overt myocardial ischemia.

Funding Acknowledgement

Type of funding sources: None.

Early diagnostic markers in predicting the severity of dengue disease

The aim of the present study was to determine whether the serum ferritin, the biomarker of an acute phase reactant and the gall bladder wall edema, an early indicator of capillary leakage can predict the severity of dengue fever. This study included 131 patients, who were between the age group of 18–80 years. The patients presented to our department with an acute illness, within the first four days of high temperature. The statistical analysis of this study was performed by using the Chi-square and independent Student’s t tests. The diagnostic markers are considered statistically significant, if the serum ferritin level is higher than 500 ng/ml and the gall bladder wall thickness is more than 3 mm. The present study observed that, 39 patients (89%) who had severe dengue (n = 44) revealed a significant gall bladder wall thickening, and this correlation was significant statistically (p < 0.000). It was also observed that, the ferritin levels have a highly significant positive correlation with the severity of dengue. The severe dengue patients had a mean ferritin level of 9125.34 μg/l, whereas the non-severe group had 4271 μg/l. This comparison was also statistically significant, as the p value was 0.003. We report that the serum ferritin levels have a highly significant positive correlation with the severity of dengue. The gall bladder wall edema during the third and fourth day of the illness was also associated with severe dengue. However, diffuse gall bladder wall thickening and high serum ferritin levels are also reported in various other conditions and their exact cause have to be determined by the correlation of associated clinical findings and imaging features.

Risk Assessment for Diabetes Mellitus by Using Indian Diabetes Risk Score Among Office Workers of Health Institutions of South India

BACKGROUND

Diabetes mellitus (DM) is one of the non-communicable diseases plaguing the world and contributes a major part to the total disease burden. Diabetes has been prevalent in all countries throughout the years, with the majority of diabetics living in low- and middle-income countries. Madras Diabetes Research Foundation developed the Indian Diabetes Risk Score (IDRS), a simple and cost-effective method to assess the chances of developing diabetes.

OBJECTIVES

To assess the diabetes risk profile of office workers using IDRS and to determine the proportion of individual risk factors of diabetes among the participants.

METHODS

This cross sectional study included 94 non-diabetic office workers working in two health care institutions situated in coastal South India. Data was collected by a study questionnaire consisting of three sections. Section A included details related to participant characteristics, Section B included anthropometric measurements, and Section C consisted of the Indian Diabetes Risk Score. The collected data were coded and entered into Statistical Package for Social Sciences.

RESULTS

The mean age of the study participants was 40.88 (±9.761) years, and the mean BMI was 23.8 (±3.6) kg/m2. Majority (n=65, 67%) of the study participants did not have a family history of diabetes. One-third of the study participants had IDRS ≥ 60, which allocated them in the high risk category for type 2 diabetes (n=34, 35.1%).

CONCLUSION

It has been conclusively shown from the study that most of the office workers have moderate to high risk of developing diabetes and are also overweight or obese.

Occupation Hazards - Pattern, Awareness and Preventive Measures among Welders from an Unorganized Sector in India

INTRODUCTION

Welding is an occupation associated with tremendous physical and chemical hazards. In spite of the risk involved, usage of Personal Protective Gears (PPGs) among welders in developing countries has been reported to be poor, due to their limited awareness of occupational hazards.

AIM

To assess morbidity pattern, awareness of occupational hazards and usage practices of protective gears among welders.

MATERIALS AND METHODS

Cross-sectional study was conducted at welding sites from unorganized sector situated in and around Mangalore. A total of 155 welders chosen randomly from as many sites were interviewed at their workplace using a pilot tested structured interview schedule with both closed and open ended questions. Clinical examination of the participant and inspection of the work site was also done by the investigators. Statistical analysis used for analysis was Chi-Square test, unpaired t-test and ANOVA test.

RESULTS

Working >8 hours a day was reported by 30 (19.4%) welders. Overcrowding was present at 10.3%, ventilation status was inadequate at 6.9% and exhaust ventilation was not present at 25.9% sites. Awareness about occupational health hazards associated with welding was present among 97(62.6%) welders. Periodicity of medical examination was associated with awareness of occupational hazards among welders (p=0.032). First aid kit was present at 60 (38.7%) sites. The most common morbidity over the past year was wounds 119 (76.8%). Non-usage of most essential protective gears such as face shields, masks or eye goggles was seen among 18 (11.6%) welders. Mean number of morbidities over the past one month was found to be more, in those welders doing continuous work of ≥6 hours (p=0.05), at sites with overcrowding (p=0.002) and at sites where >10 welders work together (p=0.031).

CONCLUSION

The period prevalence of morbidity was high among the welders surveyed. Ignorance of health hazards associated with occupation and non-usage of protective gears was reported by number of them. Therefore, health education and safety policies need to be strengthened at welding sites.

Mitochondrial vitamin B12-binding proteins in patients with inborn errors of cobalamin metabolism

Inborn errors of vitamin B12 (cobalamin, Cbl) metabolism are autosomal recessive disorders and have been classified into nine distinct complementation classes (cblA-cblH and mut). Disorders affecting methylcobalamin metabolism cause megaloblastic anemia, which may be accompanied by leukopenia and thrombocytopenia, and a variety of neurological problems. Disorders affecting adenosylcobalamin cause methylmalonic acidemia and metabolic acidosis. Previous studies have shown that cobalamin binds to two enzymes in humans: methylmalonyl-CoA mutase in mitochondria and methionine synthase in the cytosol. In this study, cobalamin binding patterns were analyzed in crude mitochondrial fractions obtained from both control and patient fibroblasts that had been incubated with [57Co]cyanocobalamin. Crude mitochondrial fractions from control fibroblasts confirmed that the majority of [57Co]Cbl eluted with methylmalonyl-CoA mutase. However, in six of the nine disorders, at least one previously unidentified mitochondrial cobalamin binding protein was observed to bind [57Co]Cbl. The proportion of [57Co]Cbl that binds, is increased compared to controls when a deficiency in either adenosylcobalamin synthesis or utilization prevents binding to methylmalonyl-CoA mutase. Furthermore, unique cobalamin binding profiles emerged demonstrating how known mutations in these patients affect cobalamin binding to as yet unidentified proteins.