Current Cardiology Reviews - Volume 19, Issue 1, 2023

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been demonstrated as a major risk factor in inducing coronary stent thrombosis due to its propensity to create a pro-thrombotic state. This review explores the mechanisms that may contribute to the increased thrombosis risk seen in COVID-19. Furthermore, we discuss the patient and haematological factors that predispose to an increased risk of stent thrombosis, as well as the role of certain antiplatelet and anticoagulation therapies, including ticagrelor and enoxaparin, that may reduce the likelihood and severity of in-stent thrombosis, in SARS-CoV-2 infection. To counter the proinflammatory and pro-thrombotic state shown in COVID-19, anti-thrombotic therapy in the future may be optimised using point-of-care platelet inhibition testing and inflammation-modifying therapies. Large-scale randomised trials with long-term follow-up are increasingly necessary to assess the intersection of COVID-19 and stent optimisation as well as the reduction of stent thrombosis after drug-eluting stent (DES) implantation.

The laboratory methods for the determination of cardiac troponins (cTnI, cTnT) used nowadays are extremely diverse, which has a significant impact on our understanding of the biology and diagnostic the value of cTnI and cTnT as biomarkers. The main classification of methods for the determination of cTnI and cTnT is based on the sensitivity of the immunoassay. Low- and moderately sensitive detection methods are known to be relatively less sensitive, which leads to a relatively late confirmation of cardiomyocyte death. Due to the new highly sensitive methods used to determine cTnI and cTnT, designated as a highly or ultrasensitive immunoassays (hs-TnT and hs-TnT), we received new, revised data about the biology of cardiac troponin molecules. In particular, it became clear that they can be considered products of normal myocardium metabolism since hs-TnT and hs-TnT are detected in almost all healthy patients. It also turned out that hs-TnT and hs-TnT differ by gender (in men, troponin concentration in the blood is higher than in women), age (in elderly patients, the levels of troponins are higher than in young ones) and circadian cycles (morning concentrations of troponins are higher than in the evening). A large variety of methods for determining cTnI and cTnT, differing in their diagnostic capabilities, creates the need for tests to perform an unbiased assessment of the analytical characteristics of each method. This review focuses on the most pressing issues related to the discussion of the biological characteristics of cardiac troponin and the analytical characteristics of troponin immunoassays from a historical and contemporary point of view.

Aortic valve insufficiency (AI) describes the pathology of blood leaking through the aortic valve to the left ventricle during diastole and is classified as mild, moderate or severe according to the volume of regurgitating blood. Intervention is required in severe AI when the patient is symptomatic or when the left ventricular function is impaired. Aortic valve replacement has been considered the gold standard for decades for these patients, but several repair techniques have recently emerged that offer exceptional stability and long-term outcomes. The appropriate method of repair is selected based on the mechanism of AI and each patient’s anatomic variations. This review aims to describe different pathologies of AI based on its anatomy, along with the different surgical techniques of aortic repair and their reported results.

Background: Coronary bifurcation stenting constitutes 20% of all PCI performed. Given the extensive prevalence of bifurcation lesions, various techniques have sought to optimally stent the bifurcation to improve revascularization while also decreasing rates of stent thrombosis and lesion recurrence. Advanced techniques, such as planned two-stent approaches, have been shown to have improved outcomes but also require fluoroscopy and procedure time, posing an economic argument as well as a patient-outcome one. Objective: Because of the many strategies posited in the literature, it becomes essential to objectively evaluate evidence from randomized controlled trials and meta-analyses to help determine the optimal stenting strategy. Methods: We reviewed the clinical evidence on the efficacy of coronary bifurcation stenting. Results: In this paper, we review the most recent randomized controlled trials and meta-analyses on the efficacy of various stenting techniques and advances in stenting technologies published to gauge the current state of understanding and chart where the field is heading. Conclusion: Bifurcation stenting is a maturing problem in the field of interventional cardiology that is adapting to the needs of the patients and advances in technology.

The acute coronary syndrome is one of the commonest life-threatening illnesses. It encompasses the clinical spectrum of acute myocardial ischemia and includes unstable angina and acute myocardial infarction both with and without ST segment elevation. The acute coronary syndrome can be attributed to a significant hemodynamic insult that leads to atherosclerosis of the epicardial coronary arteries. The main causative risk factors, such as obesity, smoking, and alcohol intake, increase the burden of acute coronary syndrome. Owing to an increase in the utilization of antioxidants, the antioxidant capacity decreases concerning the scavenging of lipid peroxides. Moreover, the thyroid hormones are important regulators of the expression of cardiac genes, and many of the cardiac manifestations of thyroid dysfunction are associated with alterations in triiodothyronine- mediated gene expression. Cardiovascular signs and symptoms of thyroid disease are among the most acute clinically relevant findings that occur in combination with both hypothyroidism and hyperthyroidism. By understanding the cellular mechanism of the action of thyroid hormones on the heart and cardiovascular system, it is possible to explain rhythm disturbances and alterations in cardiac output, blood pressure, cardiac contractility, and vascular resistance that result from thyroid dysfunction. Oxidative stress is thereby induced, together with a decrease in antioxidant capacity for overcoming oxidative stress, which leads to endothelial dysfunction, subsequent atherosclerosis, and, ultimately, acute myocardial infarction. The implications for the identification of the effects of thyroid disease on acute myocardial infarction include the observation that restoration of normal thyroid function repeatedly reverses abnormalities in cardiovascular hemodynamics.

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable efficacy in treating highly refractory and relapsing hematological malignancies in pediatric and adult patients. However, this promising therapy is limited by severe and potentially life-threatening toxicities. Cytokine release syndrome (CRS) is the most commonly observed of these toxicities. The cardiovascular manifestations of CRS include tachycardia, hypotension, left ventricular dysfunction, arrhythmias, troponin elevation, cardiogenic shock, and pulmonary edema. Recent data suggest that cardiotoxicities may be transient and reversible in younger patients with few cardiac comorbidities; however, cardiotoxicities may be fatal in older patients with significant cardiac risk factors. The literature remains sparse regarding long-term cardiotoxicities associated with CAR-T cell therapy. Furthermore, consensus guidelines for monitoring and prevention of cardiotoxicities remain illdefined. Therefore, this review will detail the cardiovascular toxicities of CAR T-cell therapy seen in clinical trials and observational studies, summarize treatment approaches for CRS, outline the currently adopted surveillance protocols for CAR T-cell associated cardiotoxicity, and explore the future directions of research in this rapidly emerging field.

Background: There is a significant increase in morbidity and mortality in patients complicated by major bleeding following transcatheter aortic valve replacement (TAVR). It has become more challenging to manage such complications when the patient needs to be on anticoagulation or antiplatelet agent post-procedure to prevent thrombotic/embolic complications. Methods: We systematically reviewed all available randomized controlled trials and observational studies to identify incidence rates of gastrointestinal bleeding post-procedure. After performing a systematic search, a total of 8731 patients from 15 studies (5 RCTs and 10 non-RCTs) were included in this review. Results: The average rate of gastrointestinal bleeding during follow-up was 3.0% in randomized controlled trials and 1.9% among observational studies. Conclusion: Gastrointestinal bleeding has been noted to be higher in the RCTs as compared to observational studies. This review expands knowledge of current guidelines and possible management of patients undergoing TAVR.

Introduction: COVID-19 is often seen presenting with a myriad of signs and symptoms of multiorgan dysfunction including arterial dissection. Methods: Various theories have been proposed such as endothelial dysfunction triggered by hyperinflammatory response that results in rupture of atherosclerotic plaque and subsequent dissection. Results: However, the exact incidence is unknown and only case reports and case series have been published till date. Conclusion: Here we carried out a systematic analysis of published case reports/series related to dissection of the aorta, coronary, cerebral, vertebral, cervical, renal, and splanchnic arteries.

Purpose: This review aims to summarize and evaluate the most accurate machinelearning algorithm used to predict ischemic heart disease. Methods: This systematic review was performed following PRISMA guidelines. A comprehensive search was carried out using multiple databases such as Science Direct, PubMed\ MEDLINE, CINAHL, and IEEE explore. Results: Thirteen articles published between 2017 to 2021 were eligible for inclusion. Three themes were extracted: the commonly used algorithm to predict ischemic heart disease, the accuracy of algorithms to predict ischemic heart disease, and the clinical outcomes to improve the quality of care. All methods have utilized supervised and unsupervised machine-learning. Conclusion: Applying machine-learning is expected to assist clinicians in interpreting patients’ data and implementing optimal algorithms for their datasets. Furthermore, machine-learning can build evidence-based that supports health care providers to manage individual situations who need invasive procedures such as catheterizations.

Background: The development of atrioventricular bioprosthesis has witnessed an increasing drive toward clinical translation over the last few decades. A significant challenge in the clinical translation of an atrioventricular bioprosthesis from bench to bedside is the appropriate choice of a large animal model to test the safety and effectiveness of the device. Methods: We conducted a systematic review of pre-clinical in vivo studies that would enable us to synthesize a recommended framework. PRISMA (Preferred Reporting Items for Systematic Reviews and MetaAnalyses) guidelines were followed to identify and extract relevant articles. Results: Sheep was the most common choice of animal, with nine out of the 12 included studies being conducted on sheep. There were acute and chronic studies based on our search criteria. An average of ∼20 and 5 animals were used for chronic and acute studies. One out of three acute studies and eight out of nine chronic studies were on stented heart valve bioprosthesis. All analyses were conducted on the implantation of atrioventricular valves with trileaflet, except for one chronic study on unileaflet valves and one chronic and acute study on bileaflet valves. Conclusion: Understanding the variance in past pre-clinical study designs may increase the appropriate utilization of large animal models. This synthesized evidence provides a pre-clinical in vivo studies framework for future research on an atrioventricular bioprosthesis.

Background: We aimed to provide a comprehensive overview of existing gender differences in acute coronary syndrome (ACS), with respect to treatment delays, invasive management of ACS, and short and long-term mortality in patients with ACS. Methods: We defined 37 observational studies (OSs) and 21 randomized trials (RCTs) that best corresponded to our interests. OSs and RCTs were analyzed separately. Results: Women with ACS more often experienced delays in treatment compared to men (OR 1.43; 95% CI, 1.12-1.82) in RCTs. Female patients were less often treated invasively: RCTs (OR 0.87; 95% CI, 0.83-0.9), OSs: (OR 0.66; 95% CI, 0.63-0.68). Women had higher crude in-hospital mortality (OR 1.56; 95% CI, 1.53-1.59) and 30-day mortality (OR 1.71; 95% CI, 1.22-2.4) in OSs and (OR 2.74; 95% CI, 2.48-3.02) in RCTs. After adjustment for multiple covariates, gender difference was attenuated: in-hospital mortality (OR 1.19; 95% CI, 1.17-1.2), 30-day mortality (OR 1.18; 95% CI, 1.12-1.24) in OSs. Unadjusted long-term mortality in women was higher than in men (OR 1.41; 95% CI, 1.31-1.52) in RCTs and (OR 1.4; 95% CI, 1.3-1.5) in OSs. Conclusion: Women with ACS experience a delay in time to treatment more often than men. They are also less likely to be treated invasively. Females have shown worse crude short-and long-term all-cause mortality compared to males. However, after adjustment for multiple covariates, a less significant gender difference has been observed. Considering the difference between crude and adjusted mortality, we deem it reasonable to conduct further investigations on gender-related influence of particular risk factors on the outcomes of ACS.

Patients with posterior circulation ischemia due to vertebral artery stenosis account for 20 to 25% of ischemic strokes and have an increased risk of recurrent stroke. In patients treated with medical therapy alone, the risk of recurrence is particularly increased in the first few weeks after symptoms occur, with an annual stroke rate of 10 to 15%. Additionally, obstructive disease of the vertebrobasilar system carries a worse prognosis, with a 30% mortality at 2-years if managed medically without additional surgical or endovascular intervention. Percutaneous transluminal angioplasty and stenting of symptomatic vertebral artery stenosis are promising options widely used in clinical practice with good technical results; however, the improved clinical outcome has been examined in various clinical trials without a sufficient sample size to conclusively determine whether stenting is better than medical therapy. Surgical revascularization is an alternative approach for the treatment of symptomatic vertebral artery stenosis that carries a 10-20% mortality rate. Despite the advances in medical therapy and endovascular and surgical options, symptomatic vertebral artery stenosis continues to impose a high risk of stroke recurrence with associated high morbidity and mortality. This review aims to provide a focused update on the percutaneous treatment of vertebral artery stenosis, its appropriate diagnostic approach, and advances in medical therapies.