Current Cardiology Reviews - Volume 19, Issue 6, 2023

Background: Prosthetic valve endocarditis can be difficult to diagnose and cause significant morbidity and mortality, especially when no culture data are available to guide therapy. Transthoracic and transesophageal echocardiograms, the studies of choice for initial endocarditis evaluation, can be less reliable due to artifact and post-surgical changes. Some less common forms of endocarditis may be difficult to culture and, due to their fastidious nature, may delay the identification of causative organisms. Given the lack of directed antimicrobial treatment, culturenegative prosthetic valve endocarditis is specifically difficult. A wide differential diagnosis is critical to make a timely diagnosis and initiate treatment. Case Presentation: We present a case of a patient presenting with dyspnea which was found to have culture-negative endocarditis requiring mitral and aortic valve replacement that ultimately was complicated with culture-negative prosthetic valve endocarditis. Identifying a culprit organism made appropriate and timely antimicrobial treatment difficult, ultimately resulting in the patient dying from endocarditis complications. Conclusion: A high index of suspicion is needed when managing infective endocarditis, especially when prosthetic valves are involved. Diagnostic accuracy of cultures and echocardiography may be reduced when dealing with prosthetic valve endocarditis; thus, alternative methods of diagnosis may be required to make a timely diagnosis of causative organisms.

Even before its role in platelet inhibition was fully characterized in the 1980s, aspirin had been incorporated into the cardiovascular disease care algorithm. Early trials examining its use in unstable angina and acute myocardial infarction revealed evidence of its protective role in the secondary prevention of atherosclerotic cardiovascular disease (ASCVD). Large trials assessing use in the primary prevention setting and optimal dosing regimens were studied in the late 1990s and early 2000s. As a cornerstone of cardiovascular care, aspirin was incorporated into primary and secondary ASCVD prevention guidelines in the United States and mechanical heart valve guidelines. However, in recent years, with significant advances in medical and interventional ASCVD therapies, scrutiny has been placed on the bleeding profile of aspirin, and guidelines have adapted to new evidence. Updates in primary prevention guidelines reserve aspirin only for patients at higher ASCVD risk and low bleeding risk - though questions remain in ASCVD risk assessment as risk-enhancing factors have proven difficult to incorporate on a population level. New thoughts regarding aspirin use in secondary prevention - especially with the concomitant use of anticoagulants - have altered recommendations as additional data accrued. Finally, a recommendation for aspirin and vitamin K antagonists with mechanical heart valves has been modified. Despite aspirin losing a foothold in cardiovascular care, new evidence has strengthened claims for its use in women at high risk for preeclampsia.

Acute myocardial infarction is an event of myocardial necrosis caused by unstable ischemic syndrome. Myocardial infarction (MI) occurs when blood stops flowing to the cardiac tissue or myocardium and the heart muscle gets damaged due to poor perfusion and reduced oxygen supply. Mitochondria can serve as the arbiter of cell fate in response to stress. Oxidative metabolism is the function of mitochondria within the cell. Cardiac cells being highly oxidative tissue generates about 90% of their energy through oxidative metabolism. In this review, we focused on the role of mitochondria in energy generation in myocytes as well as its consequences on heart cells causing cell damage. The role of mitochondrial dysfunction due to oxidative stress, production of reactive oxygen species, and anaerobic production of lactate as a failure of oxidative metabolism are also discussed.

Congenital left ventricular outflow obstruction represents a multilevel obstruction with several morphological forms. It can involve the subvalvular, valvar, or supravalvular portion of the aortic valve complex, and may coexist. Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital LVOT obstruction. Unlike transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging, it is not bounded by a small acoustic window, needs for anaesthesia or sedation, and metallic devices. Current generations of CT scanners with excellent spatial and temporal resolution, high pitch scanning, wide detector system, dose reduction algorithms, and advanced 3-dimensional postprocessing techniques provide a high-quality alternative to CMR or diagnostic cardiac catheterization. Radiologists performing CT in young children should be familiar with the advantages and disadvantages of CT and with the typical morphological imaging features of congenital left ventricular outflow obstruction.

Coronary artery anomalies (CAA) are a diverse group of congenital anomalies and are the second most common cause of sudden cardiac death in the young population after Hypertrophic Cardiomyopathy (HCM). Symptoms range from chest pain, syncope, or sudden cardiac arrest to completely asymptomatic. The prevalence of congenital coronary artery anomalies in the general population is estimated to be between 1% and 2%. CAA often gets underdiagnosed due to the lack of knowledge of the disease process. Approximately 5% of patients with acute myocardial infarction do not have atherosclerotic coronary artery disease or luminal narrowing due to other causes. Congenital coronary artery anomalies account for 50-60% of this 5% of patients. Most patients are asymptomatic for most of their lives, and chest pain is the most common symptom in symptomatic patients when referred for coronary angiography, typically when the diagnosis is typically made. The malignant coronary artery is a rare presentation of a coronary anomaly when associated with atherosclerotic coronary artery disease or valvular heart disease. Patients with symptoms of an abnormal coronary artery origin will receive medical treatment/observation, exercise restriction, coronary angioplasty with stent deployment, or surgical repair.

Myocardial ischemic injury is a primary cause of death among various cardiovascular disorders. The condition occurs due to an interrupted supply of blood and vital nutrients (necessary for normal cellular activities and viability) to the myocardium, eventually leading to damage. Restoration of blood supply to ischemic tissue is noted to cause even more lethal reperfusion injury. Various strategies, including some conditioning techniques, like preconditioning and postconditioning, have been developed to check the detrimental effects of reperfusion injury. Many endogenous substances have been proposed to act as initiators, mediators, and end effectors of these conditioning techniques. Substances, like adenosine, bradykinin, acetylcholine, angiotensin, norepinephrine, opioids, etc., have been reported to mediate cardioprotective activity. Among these agents, adenosine has been widely studied and suggested to have the most pronounced cardioprotective effects. The current review article highlights the role of adenosine signaling in the cardioprotective mechanism of conditioning techniques. The article also provides an insight into various clinical studies that substantiate the applicability of adenosine as a cardioprotective agent in myocardial reperfusion injury.

Cardiovascular disease remains a leading cause of death worldwide despite the use of available cardiovascular disease risk prediction tools. Identification of high-risk individuals via risk stratification and screening at sub-clinical stages, which may be offered by ocular screening, is important to prevent major adverse cardiac events. Retinal microvasculature has been widely researched for potential application in both diabetes and cardiovascular disease risk prediction. However, the conjunctival microvasculature as a tool for cardiovascular disease risk prediction remains largely unexplored. The purpose of this review is to evaluate the current cardiovascular risk assessment methods, identifying gaps in the literature that imaging of the ocular microcirculation may have the potential to fill. This review also explores the themes of machine learning, risk scores, biomarkers, medical imaging, and clinical risk factors. Cardiovascular risk classification varies based on the population assessed, the risk factors included, and the assessment methods. A more tailored, standardised and feasible approach to cardiovascular risk prediction that utilises technological and medical imaging advances, which may be offered by ocular imaging, is required to support cardiovascular disease prevention strategies and clinical guidelines.

This study quantified the effect of cold or heat exposure of ambient temperature on the alteration of well-known cardiac markers. A meta-analysis was performed using the PRISMA guidelines. Peer-reviewed studies on ambient temperature and cardiac biomarkers were retrieved from MEDLINE, ScienceDirect and Google Scholar from January 2000 to February 2022. The pooled effect sizes of ambient temperature on cardiac biomarkers c-reactive protein, soluble-cell adhesion-molecule-1, soluble-intercellular-adhesion-molecule-1, total cholesterol, low-densitylipoprotein, interleukin-6, B-type-Natriuretic-Peptide; systolic/diastolic blood pressure were quantified using a random-effects meta-analysis. A total of 26 articles were included in the metaanalysis after screening the titles, abstracts and full texts. The pooled results for a 1°C decrease of ambient temperature showed an increase of 0.31% (95% CI= 0.26 to 0.38) in cardiac biomarkers (p=0.00; I-squared=99.2%; Cochran’s Q=5636.8). In contrast, the pooled results for a 1°C increase in ambient temperature showed an increase of 2.03% (95% CI= 1.08 to 3.82) in cardiac biomarkers (p=0.00; I-squared=95.7%; Cochran’s Q=235.2). In the cardiovascular (CV) population, the percent increase in cardiac biomarkers levels due to a decrease/increase in ambient temperature was greater. This study showed the decrease/increase in ambient temperature has a direct correlation with the alterations in cardiac biomarkers. These findings are useful for managing temperatureassociated cardiovascular mortality.

Arrhythmias are an increasingly common cause of hospital admissions worldwide. Late detection of arrhythmias is associated with a significantly increased risk of cardiovascular complications. Early identification and management of life-threatening arrhythmias is paramount to reduce mortality. Wearable technologies are now widespread among the general population, providing a continuous output of healthcare data. However, this data are not routinely integrated into clinical practice. Here, we begin by outlining the current landscape in wearable technology for aiding arrhythmia detection; we then consider the clinical impact of wearable technology for both clinicians and patients; we further highlight the latest and emerging trials in wearable technology for arrhythmia detection and finally postulate the wider implications of the expansion of such cardiac devices.