Myocardial ischemia represents a state of reduced coronary perfusion with oxygenated blood, insufficient to meet the metabolic demands of the myocardium. Both acute and chronic ischemia trigger a cascade of cellular events that lead to disturbances in ionic balance, mitochondrial function and energy metabolism. During ischemia, cardiomyocytes (CMs) shift from aerobic to anaerobic metabolism, resulting in adenosine triphosphate (ATP) depletion, loss of ionic homeostasis and calcium (Ca2+) overload that activate proteases, phospholipases and membrane damage. Reperfusion restores oxygen supply and prevents irreversible necrosis but paradoxically initiates additional injury in marginally viable myocardium. The reoxygenation phase induces excessive production of reactive oxygen species (ROS), endothelial dysfunction and a strong inflammatory response mediated by neutrophils, platelets and cytokines. Mitochondrial dysfunction and opening of the mitochondrial permeability transition pore (mPTP) further amplify oxidative stress and inflammation and trigger apoptosis and necroptosis. Understanding these intertwined cellular and molecular mechanisms remains essential for identifying novel therapeutic targets aimed at reducing reperfusion injury and improving myocardial recovery after ischemic events.
Coronary atherosclerosis in patients with diabetes mellitus is the most significant pathophysiological mechanism responsible for ischemic heart disease. Atherosclerosis in diabetes is premature, more diffuse, and more progressive, and it affects more coronary blood vessels compared to non-diabetics. Atherosclerosis begins with endothelial dysfunction, continues with the formation of fatty streaks in the intima of coronary arteries, and ends with the appearance of an atherosclerotic plaque that expands centrifugally and remodels the coronary artery. If the atherosclerotic plaque is injured, a thrombus forms at the site of the damage, which can lead to vessel occlusion and potentially fatal consequences. Diabetes mellitus and atherosclerosis are connected through several pathological pathways. Among the most significant factors that lead to atherosclerosis in diabetics are hyperglycemia, insulin resistance, oxidative stress, dyslipidemia, and chronic inflammation. Chronic inflammation is currently considered one of the most important factors in the development of atherosclerosis. However, to date, no adequate anti-inflammatory therapeutic measures have been found to prevent the progression of the atherosclerotic process, and they remain a subject of ongoing research. In this review, we summarize the most significant pathophysiological mechanisms that link atherosclerosis and diabetes mellitus.
Background and Objectives: Cardiac tamponade is managed through echo- or fluoroscopy-guided percutaneous pericardiocentesis. The European Society of Cardiology’s Working Group on Myocardial and Pericardial Diseases proposed a triage strategy for these patients. This study evaluated the triage score and compared the safety and efficacy of fluoroscopy- versus echo-guided procedures without additional visualization control. Materials and Methods: This prospective observational study included 71 patients with cardiac tamponade from February 2021 to June 2022. Pericardiocentesis was performed using fluoroscopy or echo guidance based on clinical assessment and catheterization laboratory availability, without the additional control of needle/guidewire position or ECG monitoring. Patients were followed for three months. Results: The study included 71 patients (52.1% female, mean age 59.7 ± 15.7 years). Malignancy was the most common comorbidity (59.2%). Echo criteria led to urgent procedures in 47.9%, with subcostal access used most often (60.6%), particularly in fluoroscopy-guided procedures (93.8%, p = 0.003). The success rate was 97.1%, with minor complications in 14% of patients. Diabetes and malignancy predicted complications regardless of access site or guiding method. The triage score did not affect complication rates or short-term mortality. Conclusions: Fluoroscopy- and echo-guided pericardiocentesis without additional visualization control showed no difference in safety or efficacy. Delaying the procedure for patients with a triage score ≥6, or performing it early for those with a low score, did not impact complication rates or mortality, which were more influenced by the progression of the underlying disease.
Coronary artery vasospasm (CAV) is a transient, reversible constriction of the epicardial coronary arteries that reduces coronary blood flow and may cause myocardial ischemia. Despite its clinical significance, CAV remains underdiagnosed and can present as chest pain, acute coronary syndrome, malignant arrhythmias or sudden cardiac death. Vasospasm may occur in both angiographically normal coronary arteries and at sites of pre-existing atherosclerotic stenosis. The pathophysiology of CAV is multifactorial and involves vascular smooth muscle cells (VSMCs) hyperreactivity, endothelial dysfunction, chronic inflammation and autonomic dysregulation. VSMCs contraction is mediated by phosphorylation of the myosin light chain (MLC) through calcium (Ca2+)/calmodulin-dependent myosin light chain kinase (MLCK), while relaxation is regulated by myosin light chain phosphatase (MLCP). Increased intracellular Ca2+ levels and enhanced Ca2+ sensitivity contribute to excessive vasoconstriction. Rho-kinase (ROCK) plays a pivotal role in sustained vasospasm by inhibiting MLCP, thereby promoting prolonged smooth muscle contraction. Endothelial dysfunction contributes to CAV by disrupting normal vascular tone regulation, largely as a result of decreased nitric oxide (NO) mediated vasodilation. Chronic low-grade inflammation and oxidative stress exacerbate both endothelial dysfunction and VSMCs contraction. Understanding these molecular mechanisms is essential for identifying novel therapeutic targets. Emerging treatment strategies, including ROCK inhibitors, endothelin receptor antagonists and anti-inflammatory agents, may improve outcomes in patients with refractory CAV.