Hospital attendance and admission trends for cardiac diseases during the COVID-19 outbreak and lockdown in Greece.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) outbreak, along with implementation of lockdown and strict public movement restrictions, in Greece has affected hospital visits and admissions. We aimed to investigate trends of cardiac disease admissions during the outbreak of the pandemic and possible associations with the applied restrictive measures. STUDY DESIGN: This is a retrospective observational study. METHODS: Data for 4970 patients admitted via the cardiology emergency department (ED) across 3 large-volume urban hospitals in Athens and 2 regional/rural hospitals from February 3, 2020, up to April 12 were recorded. Data from the equivalent (for the COVID-19 outbreak) time period of 2019 and from the postlockdown time period were also collected. RESULTS: A falling trend of cardiology ED visits and hospital admissions was observed starting from the week when the restrictive measures due to COVID-19 were implemented. Compared with the pre-COVID-19 outbreak time period, acute coronary syndrome (ACS) [145 (29/week) vs. 60 (12/week), -59%, P < 0.001], ST elevation myocardial infarction [46 (9.2/week) vs. 21 (4.2/week), -54%, P = 0.002], and non-ST elevation ACS [99 cases (19.8/week) vs. 39 (7.8/week), -60% P < 0.001] were reduced at the COVID-19 outbreak time period. Reductions were also noted for heart failure worsening and arrhythmias. The ED visits in the postlockdown period were significantly higher than in the COVID-19 outbreak time period (1511 vs 660; P < 0.05). CONCLUSION: Our data show significant drops in cardiology visits and admissions during the COVID-19 outbreak time period. Whether this results from restrictive measures or depicts a true reduction of cardiac disease cases warrants further investigation.

PCSK9 and inflammatory biomarkers in the early post kidney transplantation period.

OBJECTIVE:   Various biomarkers have been studied in the early post-kidney transplantation (post-KTx) period in order to identify potential therapeutic targets for improving long-term graft survival. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a biomarker that has recently gained interest in cardiovascular disease but its role still remains to be defined post-KTx. PATIENTS AND METHODS: We prospectively evaluated the levels of PCSK9, interleukin (IL)-6, WBC and C-reactive protein in seventy-three hemodialysis patients undergoing KTx, at 3 time-points; pre-transplantation (day 0) and at 1 and 6-months post-KTx. All data were also analyzed according to donor-type (living or deceased) and compared with hemodialysis patients on transplant waiting list. RESULTS: At Day 0 there was no difference in WBC, CRP, IL-6 and PCSK9 levels between patients scheduled for transplantation and those who remained on hemodialysis. In transplanted patients WBC, CRP and IL-6 levels were significantly reduced early post-KTx [logIL-6 Day 0: 0.68 (0.33, 0.85) vs. 1-month: 0.57 (0.37, 0.75) vs. 6-months: 0.50 (0.32, 0.69) pg/ml, p=0.01], while PCSK9 levels were significantly increased (Day 0: 199.8±63.0 vs. 1-month: 276.2±79.4 vs. 6-months: 245.9±62.5 ng/ml, p<0.001). In contrast, no change of WBC, CRP, IL-6 and PCSK9 levels was observed in hemodialysis patients on follow-up (p=NS for all). Between living-donor and deceased-donor recipients, analysis showed reduced CRP and increased PCSK9 levels in both groups (p<0.05 for all), while IL-6 levels were reduced in living-donor and increased in deceased-donor recipients 1-month post-KTx. PCSK9 levels were not correlated with renal function, delayed graft function, rejection episodes or inflammatory biomarkers. CONCLUSIONS: PCSK9 levels were increased post-KTx independently from renal function and inflammatory biomarkers, in both living and deceased-donor recipients.

The effect of per os colchicine administration in combination with fenofibrate and N-acetylcysteine on triglyceride levels and the development of atherosclerotic lesions in cholesterol-fed rabbits.

OBJECTIVE: Atherosclerosis is a chronic inflammatory disease promoted by pro-inflammatory cytokines produced by NOD-, LRR- and pyrin domain-containing protein 3 (NLRP 3) inflammasome. Colchicine is an anti-inflammatory agent that inhibits inflammasome's action and stabilizes atherosclerotic lesions. N-acetylcysteine (NAC) reduces low-density lipoprotein (LDL) oxidation, metalloproteinase levels, and foam cell count and volume. Fenofibrate also has antioxidant, anti-inflammatory, and anticoagulant properties while also having a beneficial effect on the vasomotor function of the endothelium. The purpose of this study is to investigate the effect of per os colchicine administration in combination with fenofibrate and NAC on triglyceride levels and the development of atherosclerotic lesions in cholesterol-fed rabbits. MATERIALS AND METHODS: Twenty-eight male, 2 months old New Zealand White rabbits were separated into four groups and were fed with different types of diet for 7 weeks: standard, cholesterol 1% w/w, cholesterol 1% w/w plus colchicine 2 mg/kg body weight plus 250 mg/kg body weight/day fenofibrate, and cholesterol 1% w/w plus colchicine 2 mg/kg body weight plus 15 mg/kg body weight/day NAC. Blood samples were drawn from all animals. Lipid profiles were assessed, and interleukin 6 (IL-6) measurements were performed using an enzyme-linked immunosorbent assay (ELISA) kit. Histologic examination was performed on aorta specimens stained with eosin and hematoxylin. Aortic intimal thickness was evaluated using image analysis. RESULTS: Colchicine administration in combination with fenofibrate or NAC statistically significantly reduced the extent of atherosclerotic lesions in aortic preparations. Co-administration of colchicine with NAC has a stronger anti-atherogenic effect than the colchicine plus fenofibrate regimen. Triglerycide levels were decreased in the colchicine plus fenofibrate group and the colchicine plus NAC group at the end of the experiment (p < 0.05), whereas the Cholesterol group had increased levels. A favorable significant lower concentration of IL-6 was detected in the colchicine plus NAC group vs. the other groups. CONCLUSIONS: In an experimental rabbit model, it appears that colchicine statistically significantly reduces the development of atherosclerosis of the aorta, especially in combination with NAC. Colchicine, as an NLRP3 inflammasome inhibitor, and NAC, as an agent that directly targets IL-6 signaling, can reduce the inflammatory risk. Fenofibrate enhances the attenuating role of colchicine on triglyceride levels. Clinical studies should investigate whether similar effects can be observed in humans.

Endothelial dysfunction: potential clinical implications.

Vascular endothelium is responsible for the secretion of several substances exerting anti-atherogenic effects. Endothelial damage is also crucial for the progress of atherosclerosis and risk factors for atherosclerosis represent crucial factors associated with endothelial dysfunction. Studies have shown that patients with cardiovascular disease are characterized by impaired endothelial function (EF). Therefore, several agents have been proposed as potential modulators of EF. Most of the available approaches include pharmaceutical agents routinely used such as statins, angiotensin converting enzyme inhibitors, antioxidants, L-arginine, insulin sensitizers or others still under investigation such as tetrahydrobiopterin or folic acid (folate). Despite of the fact that there are several strategies aiming to improve endothelial dysfunction by enhancing nitric oxide bioavailability, it is still unclear whether they could be beneficial at a clinical level.

Cardiac allograft vasculopathy after heart transplantation: current prevention and treatment strategies.

OBJECTIVE: Cardiac allograft vasculopathy (CAV) is a leading cause of mortality in heart transplantation patients. Despite optimal immunosuppression therapy, the rate of CAV post-transplantation remains high. In this review, we gathered all recent studies as well as experimental evidence focusing on the prevention and treatment strategies regarding CAV after heart transplantation. MATERIALS AND METHODS: A complete literature survey was performed using the PubMed database search to gather available information regarding prevention and treatment strategies of CAV after heart transplantation. RESULTS: Several non-immune and immune factors have been linked to CAV such as ischemic reperfusion injury, metabolic disorders, cytomegalovirus infection, coronary endothelial dysfunction, injury and inflammation respectively. Serial coronary angiography combined with intravascular ultrasound is currently the method of choice for detecting early disease. Biomarkers and noninvasive imaging can also assist in the early identification of CAV. Treatment strategies such as mammalian target of rapamycin inhibitors proceed to grow, but prevention remains the objective. CONCLUSIONS: Early detection is the key to therapy management. It enables early identification and diagnosis of patients with CAV, who would gain the most from prompt treatment. Further investigation is needed to elucidate the multifactorial pathophysiological process of CAV, develop detection methods and find treatments that prevent or slow disease progression.

Flavonoids in atherosclerosis: an overview of their mechanisms of action.

Polyphenols are composed of a wide variety of molecules that are classified into several categories, according to their chemical type such as phenolic acids, flavonoids, stilbenes, and lignans. Many studies have proven the beneficial effects of flavonoids in atherosclerosis progression and cardiovascular disease. Dietary flavonoids reduce oxidative stress and exert anti-inflammatory actions. Moreover, flavonoids have the ability to avoid the thrombus formation, improve endothelial function, modify lipid levels and regulate glucose metabolism. In the context of this evidence in this review article we summarize the so far acquired knowledge of the most important mechanisms of action of flavonoids in atherosclerosis progression.

Ultrasound contrast agents: updated data on safety profile.

Contrast echocardiography represents a major technological advancement in the constantly evolving field of cardiovascular imaging. Over the last twenty years numerous studies have been published, illustrating the incremental value of contrast implementation into a variety of clinical scenarios. However, serious concerns have been raised about contrast safety profile, mainly based on postmarketing observational data and several animal studies. The latter have investigated contrast bio effects under experimental conditions that are not consistent with daily clinical practice. On the other hand, numerous clinical trials with large registries have proven otherwise. Not only contrast agents are efficient, but they also demonstrate a remarkable safety profile. So the question is: should we fear contrast utilization or should we consider them as an adjunctive and indispensable clinical tool for daily bedside practice?

Novel biomarkers assessing the calcium deposition in coronary artery disease.

Coronary atherosclerosis is the pathophysiologic background of coronary artery disease. Vascular calcification is an actively regulated form of calcified tissue metabolism and a common feature of coronary atherosclerotic plaques. Interestingly, systematic research has revealed that vascular mineralization, is also a strong and independent predictor of cardiovascular morbidity and mortality. Recently, several biomarkers, including osteopontin, fetuin-A, matrix-carboxyglutamic acid protein, pyrophosphates, bone morphogenetic proteins, leptin, osteoprotegerin have emerged as surrogate markers of coronary calcification. Furthermore, biomarkers of vascular calcification can be used as prognostic markers of coronary artery disease and can predict future cardiovascular events and mortality. Nevertheless, there is little knowledge on the usefulness of these biomarkers in evaluating the results of treatments targeting coronary artery disease. Within this context, the present review sets out to discuss the role of new biomarkers assessing calcium deposition in coronary arteries and their role in the prognosis, progression, and treatment of cardiovascular disease.

Adiponectin and cardiovascular disease: mechanisms and new therapeutic approaches.

Adiponectin is an abundant plasma protein secreted from adipocytes. Its role in energy homeostasis is well-known, including the regulation of hydrocarbons and lipids metabolism as well as the improvement of insulin resistance. It has been thought to be a key molecule in the development of type 2 diabetes mellitus and metabolic syndrome, which are epidemiological targets for preventing cardiovascular disease. In addition to beneficial metabolic effects, adiponectin seems to have anti-inflammatory, anti-atherosclerotic and vasoprotective actions. Furthermore, adiponectin affects signalling in myocardial cells and exerts beneficial actions on the heart after pressure overload and ischemia-reperfusion injury. The ability of adiponectin to reduce insulin resistance in conjunction with its antiinflammatory and cardioprotective properties makes this adipocytokine a promising therapeutic target. On clinical interest, agents that enhance endogenous adiponectin production or action have potential for the treatment of cardiovascular disease. Management strategies that increase adiponectin levels include weight reduction, Mediterranean diet, thiazolidinediones, antihypertensive and lipid lowering drugs. Current knowledge on the main actions of adiponectin and therapeutic approaches for cardiovascular disease is summarized in this review.

Assessment of acute coronary syndromes: focus on novel biomarkers.

Coronary artery disease (CAD) is the leading cause of mortality in Western Societies and several developing countries. Recent evidence suggests that most detrimental clinical manifestations of CAD, such as acute coronary syndromes (ACS), are the outcome of inflammatory processes that lead to plaque formation and rupture and eventually to ischemia and potentially myocardial necrosis. Neither of the traditionally used biomarkers is thought to be the gold standard in detection of myocardial ischemia or necrosis. A biomarker that could detect quite early the ischemic myocardium as well as define the risk of a future event with high sensitivity and specificity is still lacking. Several biomarkers, implicated in the pathogenesis and clinical evolution of atherosclerosis, have emerged as potent biomarkers for early detection of myocardial ischemia. In the current review, we summarize recent evidence of the most promising biomarkers and discuss their potential role in clinical practice in patients suffering from ACSs.

Biomarkers determining cardiovascular risk in patients with kidney disease.

Cardiovascular disease (CVD) remains the leading cause of premature death in patients with chronic kidney disease (CKD). Recent evidence suggests that the interaction of "classic" and "non-classic" cardiovascular risk factors is an important contributor in excessive and accelerated CVD in patients with CKD. Indeed, the imposing cardiovascular morbidity and mortality of CKD patients corresponds to a significant extent in endothelial dysfunction, inflammation, oxidative stress, vascular calcification and volume overload. In addition, the kidney's function decline is independently associated with CVD in patients with chronic kidney disease. Currently, there is a growing interest in the role of new biomarkers that are closely correlated with CVD in CKD population. In current review, we summarize the so far acquired knowledge of the most promising biomarkers and we discuss the major clinical correlations of novel risk factors and new biomarkers of CVD in CKD patients, their predictive value for future cardiovascular events and their use in the treatment monitoring of this population.

The role of microRNAs in cardiovascular disease.

Cardiovascular disease, which is multifactorial and can be influenced by a multitude of environmental and heritable risk factors, remains a major health problem, even though its pathophysiology is far from been elucidated. Discovered just over a decade ago, microRNAs comprise short, non-coding RNAs, which have evoked a great deal of interest, due to their importance for many aspects of homeostasis and disease. Hundreds of different microRNAs are constantly being reported in various organisms. According to a growing body of literature, they have been implicated in the regulation of human physiological processes. More specifically, miRNAs are expressed in the cardiovascular system and could have crucial roles in normal development and physiology, as well as in disease development. Furthermore, they have been shown to participate in cardiovascular disease pathogenesis including atherosclerosis, coronary artery disease, myocardial infarction, heart failure and cardiac arrhythmias. In contrast to our original thought, miRNAs exist in circulating blood and are relatively stable, thus, they could be proved useful as biomarkers in that state. Understanding the underlying mechanisms, in which these major regulatory gene families are implicated, will provide novel opportunities for diagnosis and therapy of cardiovascular diseases.

Predictive value of biomarkers in patients with heart failure.

Heart failure (HF) is a complex syndrome with high morbidity and mortality while, myocardial injury, hemodynamic overload, genetic, neurohormonal, inflammatory and biochemical factors are implicated in the development and progression of the disease. Interestingly, despite the development of several diagnostic tests, HF diagnosis remains clinical, based on symptoms and signs, while there is a poor relationship between symptoms and the prognosis of HF. Several biomarkers have recently been examined for their efficacy to predict outcome and assess prognosis of HF patients. The best studied for its prognostic ability sub-group of biomarkers is the neurohormones including the natriuretic peptides, the components of the renin-angiotensin-aldosterone system and the catecholamines. Others sub-groups of biomarkers include inflammatory and oxidative stress markers, extracellular matrix remodeling markers and myocardial injury markers (such as troponins I and T). Nevertheless, it is difficult to access a single biomarker fulfilling our need to evaluate prognosis and guiding treatment in acute or chronic HF patients, thus the predictive ability of combined biomarkers is recently under research. Therefore, further studies are needed to elucidate the clinical significance of these biomarkers. In the present review, we will discuss the usefulness and significance of potentials or established biomarkers in HF patients focusing on their ability to predict adverse events, morbidity and mortality.

Circulating endothelial progenitor cells as biomarkers for prediction of cardiovascular outcomes.

Experimental studies suggest that bone marrow-derived endothelial progenitor cells (EPCs) play an important role in the maintenance of endothelial integrity and hemostasis. The number of circulating EPC has been shown to be inversely correlated with cardiovascular risk factors and vascular function and to predict cardiovascular events independent of both traditional and non-traditional risk factors. Thus, EPCs provide a clinical advantage over the use of other biomarkers as their measurement is directly associated with endothelial function, and available evidence suggests that they are consistently and significantly associated with a spectrum of cardiovascular complications, such as acute coronary syndromes and coronary artery disease. However, many issues in the field of EPC isolation and identification, particularly in regards to the effective and unequivocal molecular characterization of these cells still remain unresolved. In addition, simple EPC counts do not adequately describe cardiovascular disease risk. This limitation is attributable to variation in the definition of EPCs, the number of existing cardiovascular risk factors in different patients as well as a difference in the interaction between EPCs and other hematopoietic progenitor, inflammatory cells or platelets.

Divergent anti-inflammatory effects of different oil acute consumption on healthy individuals.

BACKGROUND/OBJECTIVES: Inter-cellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and tumor necrosis factor-α (TNF-α), are implicated in atherogenesis. In addition, several types of oil as part of different types of diet are associated with the initiation of atherosclerosis and consequently with the risk of cardiovascular disease. However, the exact role of oil consumption on vascular inflammation remains unknown. In this parallel study, we assessed the acute effects of extra virgin olive oil, soy oil, corn oil and cod liver oil on circulating soluble(s) forms of adhesion molecules and TNF-α. SUBJECTS/METHODS: In all, 67 healthy volunteers were randomized to receive 50 ml of oil. Soluble forms of VCAM-1, ICAM-1 and TNF-α were measured by enzyme-linked immunosorbent assay at baseline and at 3 h post oil consumption. RESULTS: All types of oil had no significant effect on soluble VCAM-1 levels (P=nonsignificant (NS) for all). On the contrary, all oil types decreased ICAM-1 levels (P<0.01). Olive oil (P<0.05), soy oil and cod liver oil (P<0.01 for both) reduced TNF-α levels significantly, in contrast to corn oil, which induced a nonsignificant decrease (P=NS). Moreover, there was a significant correlation between the absolute change in ICAM-1 and TNF-α levels (ρ=0.379, P<0.05), but not between the absolute changes in VCAM-1 and TNF-α levels (ρ=0.019, P=NS). CONCLUSIONS: Acute consumption of all types of oil decreased significantly ICAM-1 levels. In addition, olive oil, soy oil and cod liver oil decreased significantly TNF-α levels. Moreover, the absolute change in TNF-α levels was correlated with the absolute change in ICAM-1 levels. These findings indicate that acute consumption of specific types of oil is associated with specific significant anti-inflammatory effects.

The role of the cytochrome P450 polymorphisms in clopidogrel efficacy and clinical utility.

Clopidogrel, an antiplatelet agent, prevents platelet aggregation by inhibiting the adenosine disphosphate (ADP) P2Y12 receptor, which is located on the platelet surface. Although dual antiplatelet therapy appears to be efficient, a considerable number of patients continue to experience adverse cardiovascular events, such as stent thrombosis. The percentage of low response to antiplatelet therapy varies from 4% to 30% of patients depending on the cut-off values. In addition, several factors such as poor absorption, drug-to-drug interactions, inadequate dosing, elevated body mass index, insulin resistance and the nature of acute coronary syndromes have been implicated in low clopidogrel response. Recently, studies have focused on the role of genetic polymorphisms encoding enzymes that participate in clopidogrel hepatic metabolism or receptors involved in intestinal absorption and ADP induced platelet aggregation, which may affect the percentage of platelet inhibition after clopidogrel administration. The management of clopidogrel resistance remains a controversial issue and additional studies are required to evaluate the safety and efficacy of increased loading of clopidogrel or replacement with other new antiplatelet agents such as prasugrel.

Circulating biomarkers for the diagnosis and prognosis of heart failure.

Despite substantial therapeutic advances, heart failure remains a syndrome associated with high morbidity and mortality. The management of heart failure remains challenging despite the recent different therapeutic advances. The emergence of cardiac biomarkers as increasingly effective clinical tools suggests the potential of a new approach to the management of patients with heart failure. A variety of circulating biomarkers of diagnostic and prognostic utility in heart failure is currently being studies in preclinical, observational and randomized prospective studies. Of the various candidate biomarkers, the greatest wealth of knowledge and clinical experience lies with the B-type naturetic peptides. However, because individual biomarkers may have limited sensitivity and specificity, a multi-marker approach, using combinations of different biomarkers that reflect different aspects of the pathophysiological milieu, would contribute to better risk stratification and optimization of therapy.

Interaction between cytokines and sCD40L in patients with stable and unstable coronary syndromes.

BACKGROUND: Evidence suggests that soluble CD40-ligand (sCD40L) is elevated in coronary artery disease (CAD) and is released from activated platelets during the acute myocardial infarction (AMI). Although sCD40L is part of immune response, the mechanisms regulating its release in different disease states remain unknown. MATERIALS AND METHODS: This study enrolled 596 subjects: 201 patients with stable CAD, 109 patients with AMI and 286 healthy controls. Circulating levels of sCD40L, interleukin-6 (IL-6), soluble vascular cell adhesion molecule-a (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Patients with AMI (n = 109) had higher levels of sCD40L and IL-6 compared to both CAD (n = 201) (P < 0.01) and controls (n = 286) (P < 0.01), while CAD also had higher levels of sCD40L and IL-6 compared to controls (P < 0.01). Similarly, sICAM-1 and sVCAM-1 levels were higher in CAD and AMI compared to controls (P < 0.05). IL-6 was the only parameter independently associated with sCD40L in healthy individuals [beta (SE):0.491(0.096), P = 0.0001]. However, in CAD or AMI, only diabetes mellitus [beta (SE): 2.689 (1.082), P = 0.044 and beta (SE): 10.406 (3.215), P = 0.002, respectively] and smoking [beta (SE): 3.470 (1.111), P = 0.002 and beta (SE): 9.694 (2.478), P = 0.0001, respectively] (but not IL-6), were independently associated with sCD40L levels. CONCLUSIONS: Both CAD and AMI are accompanied by increased levels of sCD40L in parallel with an elevation of proinflammatory cytokine IL-6 and adhesion molecules sVCAM-1 and sICAM-1. Diabetes mellitus and smoking (but not IL-6 or adhesion molecules) were the only factors independently associated with sCD40L levels in CAD and AMI patients.