Christos Kourek

• Doctor of Medicine
• Evangelismos Hospital

In humans, heart failure (HF) and cancer are among the leading causes of morbidity and mortality. A growing body of evidence highlights a bidirectional relationship between these conditions, underpinned by shared risk factors and overlapping pathophysiological pathways. This review aims to explore the emerging role of the intestinal microbiome as a...

Advanced heart failure (AHF) represents the terminal stage of heart failure (HF), characterized by persistent symptoms and functional limitations despite optimal guideline-directed medical therapy (GDMT). This review explores the clinical definition, pathophysiology, and therapeutic approaches for AHF. Characterized by severe symptoms, New York Hea...

Acute and chronic coronary artery disease (CAD) are interconnected, representing two facets of the same condition. Chronic CAD exhibits a dynamic nature, manifesting as stable or acute ischemia, or both. Myocardial ischemia can be transient and reversible. The genesis of CAD involves diverse anatomical and functional mechanisms, including endotheli...

Campylobacter jejuni, a common cause of gastroenteritis worldwide, has also been associated with rare extraintestinal infections, including myocarditis. We report a unique case of a 24-year-old male who presented with febrile diarrhea and acute chest pain. Diagnostic investigations revealed elevated cardiac troponin levels, normal electrocardiograp...

Background: Chronic kidney disease (CKD) and heart failure (HF) are interrelated conditions that exacerbate each other through mechanisms like fluid retention, neurohormonal activation, and inflammation. Red blood cell distribution width (RDW), a measure of red blood cell size variability, has emerged as a potential prognostic marker in HF. This st...

Background The use of continuous flow left ventricular assist device (CF-LVAD) has revolutionized the management of advanced heart failure. One of the major complications associated with its use is the risk of bleeding, especially in the early postoperative period. Early events of postoperative bleeding have been associated with higher morbidity an...

Myocardial cells and the extracellular matrix achieve their functions through the availability of energy. In fact, the mechanical and electrical properties of the heart are heavily dependent on the balance between energy production and consumption. The energy produced is utilized in various forms, including kinetic, dynamic, and thermal energy. Alt...

Heart failure is a complex syndrome and our understanding and therapeutic approach relies mostly on its phenotypic presentation. Notably, the heart is characterized as the most energy-consuming organ, being both a producer and consumer, in order to satisfy multiple cardiac functions: ion exchange, electromechanical coordination, excitation–contract...

Myocardial cells and extracellular matrix fulfil their goal thanks to the energetic availability. Indeed, mechanical and electrical properties of the heart are strongly depended on the energetic production-consumption equilibrium. The produced energy is used under several forms including kinetic, dynamic, thermal energy etc. Notably, as the time go...

Although the benefits of exercise training have been shown repeatedly in many studies, its relationship with the occurrence of atrial fibrillation (AF) in competitive athletes still remains controversial. In the present review, we sought to demonstrate a comprehensive report of the incidence, pathophysiology, and therapeutic approaches to AF in eli...

Ischemic stroke (IS) is a severe complication and leading cause of mortality in patients under extracorporeal membrane oxygenation (ECMO). The aim of our narrative review is to summarize the existing evidence and provide a deep examination of the diagnosis and treatment of acute ischemic stroke patients undergoing ECMO support. The incidence rate o...

Background/Objectives: Many clinical trials have shown beneficial effects of low-dose dopamine on renal function, diuresis and symptom relief, or cardiac function in hospitalized patients with acute decompensated heart failure (HF). The aim is to assess the neurohormonal effects and the effects on clinical outcomes of the addition of low-dose dopam...

Coronary heart disease and aortic stenosis are prevalent cardiovascular diseases worldwide, leading to morbidity and mortality. Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (SAVR) have therapeutic benefits, including improved postoperative quality of life (QoL) and enhanced patient functional capacity which are key i...

According to current knowledge, although the beneficial effects of regular exercise training are well recognized, there are conflicting data regarding its relation with the occurrence of atrial fibrillation (AF) in competitive athletes. The aim of this literature review was to demonstrate a comprehensive report of incidence, pathophysiology and man...

Cardiac amyloidosis is a progressive disease characterized by the buildup of amyloid fibrils in the extracellular space of the heart. It is divided in 2 main types, immunoglobulin light chain amyloidosis and transthyretin amyloidosis (ATTR), and ATTR amyloidosis is further divided in 2 subtypes, non-hereditary wild type ATTR and hereditary mutant v...

Simple Summary Evidence on cardiotoxicity prevention and treatment strategies in patients receiving anthracyclines or HER2 receptor inhibitors, vital treatments for breast cancer and hematologic malignancies, is quite a significant field of cardio-oncology. The present systematic review and meta-analysis investigated cardioprotective strategies in...

Background/Objectives: The aim of this study was to investigate the feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and thoroughly assess any potential adverse events. Methods: We conducted a prospective observational study assessing safety and feasibility, including 16...

Background/Objectives: The aim of this study was to examine the association between in-hospital initiation of sodium glucose co-transporter 2 inhibitors (SGLT2is) and outcomes in hospitalized heart failure (HHF) patients utilizing data from a Greek center. Methods: The present work was a single-center, retrospective, observational study of consecut...

Introduction Extra virgin olive oil (EVOO) polyphenols have antioxidant properties by reducing free radicals, and are also able to improve inflammatory and lipidemic profile of patients. Free radicals are involved in the oxidation of LDL cholesterol, which can be captured very efficiently by the antioxidative olive oil polyphenols. EVOO has also a...

Background: Pulmonary hypertension (PH) is a serious progressive disorder of the modern world, characterized by endothelial dysfunction and impaired vasoreactivity. Patients with PH usually present exercise intolerance from the very early stages and reduced exercise capacity. Exercise training has been shown to have beneficial effects in patients...

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. The purpose of this systematic review is to evaluate the effectiveness of exercise training on functional capacity and quality of life (QoL) in patients with RA. We performed a search in four databases, selecting clinical trials that included community or outp...

Background/Objectives: As heart failure (HF) patients face increased vulnerability to respiratory infections, optimizing pneumococcal and influenza vaccination coverage becomes pivotal for mitigating additional health risks and reducing hospitalizations, morbidity, and mortality rates within this population. In this specific subpopulation of patien...

Background/Objectives: The aim of this study was to investigate feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and assess thoroughly any potential adverse events. Methods: We conducted a safety and feasibility study including 16 ICU patients on ECMO support who were ad...

Background: Hepatopancreato and biliary (HPB) tumors represent some of the leading cancer-related causes of death worldwide, with the majority of patients undergoing surgery in the context of a multimodal treatment strategy. Consequently, the implementation of an accurate risk stratification tool is crucial to facilitate informed consent, along wit...

Chronic heart failure (HF) is a clinical syndrome with high morbidity and mortality worldwide. Cardiac rehabilitation (CR) is a medically supervised program designed to maintain or improve cardiovascular health of people living with HF, recommended by both American and European guidelines. A CR program consists of a multispecialty group including p...

Heart failure with reduced ejection fraction (HFrEF) is a complex clinical syndrome with significant morbidity and mortality and seems to be responsible for approximately 50% of heart failure cases and hospitalizations worldwide. First-line treatments of patients with HFrEF, according to the ESC and AHA guidelines, include β-blockers, angiotensin r...

Physical inactivity remains in high levels after cardiac surgery, reaching up to 50%. Patients present a significant loss of functional capacity, with prominent muscle weakness after cardiac surgery due to anesthesia, surgical incision, duration of cardiopulmonary bypass, and mechanical ventilation that affects their quality of life. These complica...

BACKGROUND Lack of mobilization and prolonged stay in the intensive care unit (ICU) are major factors resulting in the development of ICU-acquired muscle weakness (ICUAW). ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery, and may be a risk factor for prolonged duration of mechanical ventilat...

Inflammation is a major component of heart failure (HF), causing peripheral vasculopathy and cardiac remodeling. High levels of circulating inflammatory cytokines in HF patients have been well recognized. The hallmark of the inflammatory imbalance is the insufficient production of anti-inflammatory mediators, a condition that leads to dysregulated...

Spontaneous coronary artery dissection (SCAD) has been recognized as an important cause of acute coronary syndrome (ACS) in women ≤50 years old, and up to 43% of pregnancy-associated myocardial infarction. SCAD has a strong association with extra-coronary arteriopathies, including either more common entities such as dissections, intracranial or oth...

Lyophilized recombinant brain natriuretic peptide (BNP) is an exogenous peptide synthesized by artificial recombination technology, with a similar structure and similar physiological effects with the endogenous natriuretic peptide secreted by the human body. It’s main mechanism of action is to increase cyclic guanosine monophosphate by binding with...

Endothelial dysfunction and inflammation are common pathophysiological characteristics of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are recognized as useful markers of vascular damage and endothelial repair. The aim of this study was to investigate the effects of a cardiac rehabilitation program on EPCs and inflammatory profi...

Cardiac amyloidosis (CA) is a rare but potentially life-threatening disease in which misfolded proteins accumulate in the cardiac wall tissue. Heart rhythm disorders in CA, including supraventricular arrhythmias, conduction system disturbances, or ventricular arrhythmias, play a major role in CA morbidity and mortality, and thus require supplementa...

Purpose: Cardiovascular disease is commonly accompanied by renal dysfunction. Multimorbidity in hospitalized patients impacts unfavorably on prognosis and hospital stay. We aimed to illustrate the contemporary burden of cardiorenal morbidity across inpatient cardiology care in Greece. Methods: The Hellenic Cardiorenal Morbidity Snapshot (HECMOS)...

Background: Type 2 diabetes mellitus (T2DM) is a chronic metabolic syndrome characterized by insulin resistance and hyperglycemia that may lead to endothelial dysfunction, reduced functional capacity and exercise intolerance. Regular aerobic exercise has been promoted as the most beneficial non-pharmacological treatment of cardiovascular diseases....

Coronary artery aneurysms (CAAs) are rare anatomical disorders of the coronary arteries. Atherosclerosis and Kawasaki disease are the principal causes of CCAs, while other causes including genetic factors, inflammatory arterial diseases, connective tissue disorders, endothelial damage after cocaine use, iatrogenic complications after interventions...

Background Aerobic exercise, either continuous or high intensity interval training (HIIT), induces important benefits in chronic heart failure (CHF) patients. Resistance training has been also shown to be beneficial in CHF. However, data regarding combined aerobic exercise and muscle strength training is still limited. The aim of this study was to...

Spontaneous coronary artery dissection (SCAD) is a rare non-atherosclerotic cause of acute coronary syndromes defined as non-iatrogenic, non-traumatic separation of the coronary artery wall. The most common profile is a middle-aged woman between 44 and 53 years with few cardiovascular risk factors. SCAD is frequently linked with predisposing factor...

Background Cardiac graft failure may require repeat heart transplantation (HTx). Outcomes of patients that undergo repeat HTx have not been well described. Methods We compared patients that received repeat HTx with patients that received initial HTx by inquiring the United Network for Organ Sharing database between 2015–2021. The primary endpoint...

Background Available literature indicates the possible detrimental effect of gender mismatching on mortality in patients undergoing heart transplantion. Our objective was to examine the role of gender mismatching on mortality and graft rejection in patients undergoing heart transplantation in the US. Methods Data on adult patients January who unde...

Background Concerns about the impact of the new donor heart allocation system on post-transplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018. Methods Dat...

Background: Available literature indicates the possible detrimental effect of sex mismatching on mortality in patients undergoing heart transplantation. Our objective was to examine the role of sex and heart mass (PHM) mismatch on mortality and graft rejection in patients undergoing heart transplantation in the US. Methods: Data on adult patient...

Cardiotoxicity is a significant complication of chemotherapeutic agents in cancer patients. Cardiovascular incidents including LV dysfunction, heart failure (HF), severe arrhythmias, arterial hypertension, and death are associated with high morbidity and mortality. Risk stratification of cancer patients prior to initiation of chemotherapy is crucia...

Heart failure (HF) is a major public health issue worldwide with increased prevalence and a high number of hospitalizations. Patients with chronic HF and either reduced ejection fraction (HFrEF) or mildly reduced ejection fraction (HFmrEF) present vascular endothelial dysfunction and significantly decreased circulating levels of endothelial progeni...

Background: Concerns about the impact of the new donor heart allocation system on post-transplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018. Methods:...

Purpose: The purpose of this study was to investigate the effect of a cardiac rehabilitation program on the acute response on endothelial progenitor cells and circulating endothelial cells after maximal exercise in patients with chronic heart failure of different severity. Methods: Forty-four chronic heart failure patients were enrolled in a 36-...

The therapeutical advances in recent years in the field of oncology treatment have increased survival rates and improved the quality of life of oncology patients, thus turning cancer into a chronic disease. However, most of the new cancer treatments come at the expense of serious cardiovascular adverse events threatening the success story of these...

Aim: The present study investigates the effect of Strength Training addition in a High Intensity Interval Training (HIIT) program, on the inflammatory profile of chronic heart failure (CHF) patients. Materials and Methods: Forty-six CHF patients were randomized into the two different exercise rehabilitation groups. A patient group (control) perform...

Background Heart failure (HF) is a common cause of morbidity and mortality in older patients. Frailty is prevalent and complicates the course of HF. We sought to investigate the impact of frailty on HF outcomes. Methods Patients over 65 years old hospitalized with acute decompensated HF and mildly reduced or preserved EF, between September, 2017 a...

Throughout the last decades, newly developed chemotherapeutic agents and immunotherapies that target signaling pathways have provided patients with better prognoses, improved their quality of life and increased survival rates, thus converting cancer to a stable chronic disease. However, non-anthracycline cancer chemotherapy agents and immunotherapi...

The aim of this qualitative systematic review is to summarize and analyze the different modalities of exercise training and its potential effects in patients on extracorporeal membrane oxygenation (ECMO) support. ECMO is an outbreaking, life-saving technology of the last decades which is being used as a gold standard treatment in patients with seve...

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfu...

Background: Early mobilization of the Intensive Care Unit (ICU) patients improves muscle strength and functional capacity. It has been demonstrated that prevents Intensive Care Unit Acquired Weakness (ICUAW) and accelerates ICU discharge. However, data on mobilization early after cardiac surgery are inadequate. This study aimed to record early mobi...

Background: A high-cholesterol diet (HCD) induces vascular atherosclerosis through vascular inflammatory and immunological processes via TLRs. The aim of this study is to investigate the mRNA expression of TLRs and other noxious biomarkers expressing inflammation, fibrosis, apoptosis, and cardiac dysfunction in the rabbit myocardium during (a) high...

Background Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are also impaired. The purpose of the study was to assess the effect of a cardiac rehabilitation (CR) program on the increase of EPCs at rest and on the acute response after maximal exercise in...

Background: Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Patients with CHF are characterized by impaired vasodilation and inflammation of the vascular endothelium. They also have low levels of endothelial progenitor cells (EPCs). EPCs are bone marrow derived cells involved in endothel...

Background Chronic heart failure (CHF) remains a leading cause of morbidity and mortality and it is characterized by vascular endothelial dysfunction. During the last decades, endothelial progenitor cells (EPCs) are being used as an index of the endothelium restoration potential, therefore reflecting the vascular endothelial function. Exercise trai...

Background Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Endothelial progenitor cells (EPCs) are being used as an index of vascular endothelial function. Cardiac rehabilitation (CR) programs have been shown to stimulate the mobilization of EPCs in CHF patients. However, the effect of di...

Background In-hospital cardiac arrest is a major cause of death in European countries, and survival of patients remains low ranging from 20% to 25%. Aims The purpose of this study was to assess healthcare professionals’ knowledge on cardiopulmonary resuscitation among university hospitals in 12 European countries and correlate it with the return o...

Circulating or tissue-related biomarkers are of clinical value for risk stratification in patients with abdominal aortic aneurysms. Relaxin-2 (RL2) has been linked to the presence and size of arterial aneurysms, and to the extent of atherosclerosis in human subjects. Here, we assessed the expression levels of RL2 in aneurysmal (AA, n = 16) and athe...

Introduction Vascular endothelial dysfunction is an underlying pathophysiological feature of chronic heart failure (CHF). Exercise has been shown to stimulate the mobilization of endothelial progenitor cells (EPC) in healthy populations. EPC contribute to the regeneration of the inflammatory endothelium and promote neovascularization. Purpose The...

Objective: Acute effects of passive smoking on microcirculation have not been sufficiently studied. The aim of the present study was to detect microcirculatory alterations in healthy non-smokers after passive exposure to cigarette smoke, utilizing the Near Infrared Spectroscopy method combined with the vascular occlusion technique. Methods: Sixt...

Objective: To provide a comprehensive review summarizing the existing evidence on the association between nonalcoholic fatty liver disease (NAFLD) and hypertension (HT) independent of other components of metabolic syndrome. Methods: We searched the literature through Medline and the Cochrane Library for studies evaluating the relationship betwee...