Search Results (19)

The coronary no-reflow phenomenon remains a daunting and unresolved barrier during percutaneous coronary procedures, especially for acute coronary syndrome. Despite successful epicardial artery patency restoration, decreased microvascular perfusion leads to unfavorable outcomes such as ventricular remodeling, progression of heart failure, and increased mortality. This review provides a new, integrative informative perspective by combining multifactorial pathophysiology, which includes systemic inflammation, thrombogenicity, ischemia–reperfusion injury, and distal embolization, with advances in diagnostic imaging, such as cardiac magnetic resonance and computed tomography. Therapeutic options, including antithrombotic regimes, vasodilators, and mechanical adjuncts, are evaluated in the context of developing debates and unmet clinical needs. Importantly, we provide feasible future directions for artificial intelligence-based predictive modeling and targeted microvascular treatments. This comprehensive review fills a significant gap, aiming to inform personalized approaches and improve both short- and long-term outcomes in this high-risk patient population. Full article

Microvascular obstruction (MVO) accounts for up to 50% of patients diagnosed with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). The pathogenesis is multifactorial and includes myocardial ischemia, distal embolization, and ischemia–reperfusion injury, in a context of individual susceptibility. Its occurrence has been related to adverse outcomes. Despite an extensive body of research, no single pharmacological or interventional strategy has proven effectiveness. The inconclusive nature of the evidence can be attributed to lack of standardization among studies in terms of drugs used and their dosage, the variability in study designs, and the fact that available studies performed a decade ago feature reperfusion strategies and drugs used that differ significantly from the current standard of care. In this context, our review aims to discuss the pharmacological and interventional approaches to MVO. Full article

(1) Introduction: Distal coronary emboli occur in up to 15–30.5% of patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) and are associated with poor myocardial reperfusion in the territory of the infarct-related artery. The objective of this study was to analyze the possible laboratory, clinical and imaging indicators of distal coronary embolism detected with an angiography at the time of PCI with stent implantation for acute coronary syndrome (ACS). (2) Methods: This analysis included 137 patients with ACS. The levels of cardiac enzymes (creatine kinase [CK], muscle–brain fraction of CK, high-sensitivity troponin T [hsTnT]), inflammatory markers (high-sensitivity C-reactive protein, white blood cell counts), sex steroids (total 17β-estradiol, total testosterone, dehydroepiandrosterone sulfate [DHEA-S]), serum lipids and oxidized low-density lipoproteins (oxLDL) were measured and analyzed for their relationship with the incidence of distal coronary embolism at PCI. (3) Results: Slow coronary blood flow was detected in the coronary artery subject to intervention in 9.4% (n = 13) of patients. Triglyceride (TG), high-density lipoprotein (HDL), glucose and serum DHEA-S levels were found to be associated with distal coronary embolization and slow coronary flow at PCI with stenting (DHEA-S: 1.316, OR 1.044–1.659, p = 0.020; TG: 1.130, OR 0.990–1.300, p = 0.072; HDL: 2.326, OR 0.918–5.8977, p = 0.075; glucose: 1.130, OR 0.990–1.300, p = 0.072). In the multivariable model, only DHEA-S after PCI tended to indicate a risk of distal coronary embolism (DHEA-S: p = 0.071; TG: p = 0.339; glucose: p = 0.582; HDL: p = 0.502). (4) Conclusions: Patients with ACS with higher triglyceride levels are at risk of developing slow blood flow after percutaneous intervention with stent implantation. Elevated DHEA-S possibly reflects sympathoadrenal and hypothalamus–pituitary–adrenal hyperactivity associated with ACS and coronary intervention. Full article

Coronary microvascular obstruction and dysfunction (CMVO) frequently arise following primary percutaneous coronary intervention (PCI), particularly in individuals with myocardial infarction. Despite the restoration of epicardial blood flow, microvascular perfusion might still be compromised, resulting in negative clinical outcomes. CMVO is a complex condition resulting from a combination of ischemia, distal thrombotic embolization, reperfusion injury, and individual susceptibilities such as inflammation and endothelial dysfunction. The pathophysiological features of this condition include microvascular spasm, endothelial swelling, capillary plugging by leukocytes and platelets, and oxidative stress. Traditional angiographic assessments, such as Thrombolysis in Myocardial Infarction (TIMI) flow grade and myocardial blush grade, have limited sensitivity. Cardiac magnetic resonance imaging (CMR) stands as the gold standard for identifying CMVO, while the index of microvascular resistance (IMR) is a promising invasive option. Treatment approaches involve powerful antiplatelet drugs, anticoagulants, and supersaturated oxygen, yet no treatment has been definitively shown to reverse established CMVO. CMVO remains a significant therapeutic challenge in coronary artery disease management. Enhancing the comprehension of its core mechanisms is vital for the development of more effective and personalized treatment strategies. Full article

Coronary no-reflow (CNR) is the failure of blood to reperfuse ischemic myocardial tissue after restoration of the vasculature. CNR poses a significant clinical challenge in the treatment of patients with ST-segment elevation myocardial infarction (STEMI), as it increases mortality and the risk of major adverse cardiac events (MACEs). Myocardial ischemia with subsequent reperfusion results in severe damage to the cardiac microcirculation. The pathophysiological causes of CNR include cardiomyocyte vulnerability, capillary and endothelial damage, leukocyte activation, reactive oxygen species (ROS) production, and changes in microRNA profiles and related gene expression. The impact of percutaneous coronary intervention (PCI) on the occurrence of CNR cannot be overlooked, as it can provoke distal atherothrombotic embolization. Current standards of pharmacological therapy for CNR are confined to intracoronary vasodilators and antiplatelet agents. As our understanding of the pathogenesis of the CNR phenomenon improves, opportunities emerge for developing novel therapeutic strategies. The following literature review provides an overview of the pathophysiology of the no-reflow phenomenon (based on animal and preclinical studies), contemporary treatment trends, and current therapeutic approaches. Full article

Substantial evidence from previous clinical studies, randomized trials, and patient registries confirms the existence of significant differences in cardiac morphology, pathophysiology, prevalence of specific coronary artery disease (CAD), and clinical course of myocardial infarction (MI) between men and women. The aim of this review is to investigate the impact of sex or gender on the development and clinical course of MI, the mechanisms and features of left ventricular (LV) remodeling, and heart failure (HF). The main sex-related difference in post-MI LV remodeling is adverse LV dilatation in males versus concentric LV remodeling or concentric LV hypertrophy in females. In addition, women have a higher incidence of microvascular dysfunction, which manifests as impaired coronary flow reserve, distal embolism, and a higher prevalence of the no-reflow phenomenon. Consequently, impaired myocardial perfusion after MI is more common in women than in men. Regardless of age or other comorbidities, the incidence of reinfarction, hospitalization for HF, and mortality is significantly higher in females. There is therefore a “sex paradox”: despite the lower prevalence of obstructive CAD and HF with reduced ejection fraction (HFrEF), women have a higher mortality rate after MI. Different characteristics of the coronary network, such as plaque formation, microvascular dysfunction, and endothelial inflammation, as well as the prolonged time to optimal coronary flow restoration, secondary mitral regurgitation, and pulmonary vascular dysfunction, lead to a worse outcome in females. A better understanding of the mechanisms responsible for MI occurrence, LV remodeling, and HF in men and women would contribute to optimized patient therapy that would benefit both sexes. Full article

Coronary aneurysms are typically defined as sections of a coronary artery where the diameter is more than 1.5 times that of an adjacent normal segment. In rare circumstances, these aneurysms can become exceedingly large, leading to the classification of giant coronary artery aneurysms. Despite their occurrence, there is no clear consensus on the precise definition of giant coronary artery aneurysms, and their etiology remains somewhat ambiguous. Numerous potential causes have been suggested, with atherosclerosis being the most prevalent in adults, accounting for up to 50% of cases. In pediatric populations, Kawasaki disease and Takayasu arteritis are the primary causes. Although often discovered incidentally, coronary artery aneurysms can lead to severe complications. These complications include local thrombosis, distal embolization, rupture, and vasospasm, which can result in ischemia, heart failure, and arrhythmias. The optimal approach to medical, interventional, or surgical management of these aneurysms is still under debate and requires further clarification. This literature review aims to consolidate current knowledge regarding coronary artery aneurysms’ pathophysiology, emphasizing their definition, causes, complications, and treatment strategies. Recent research has begun to explore the molecular mechanisms involved in the formation and progression of coronary artery aneurysms. Various molecules, such as matrix metalloproteinases (MMPs), inflammatory cytokines, and growth factors, play crucial roles in the degradation of the extracellular matrix and the remodeling of vascular walls. Elevated levels of MMPs, particularly MMP-9, have been associated with the weakening of the arterial wall, contributing to aneurysm development. Inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1β and IL-6) have been implicated in promoting inflammatory responses that further degrade vascular integrity. Additionally, growth factors such as vascular endothelial growth factor (VEGF) may influence angiogenesis and vascular remodeling processes. Understanding these molecular pathways is essential for developing targeted therapies aimed at preventing the progression of coronary artery aneurysms and improving patient outcomes. Full article

Coronary artery aneurysm or ectasia (CAAE) is a term that includes both coronary artery ectasia (CAE) and coronary artery aneurysm (CAA), despite distinct phenotypes and definitions. This anomaly can be found in 0.15–5.3% of coronary angiography. CAE is a diffuse dilatation of the coronary artery at least 1.5 times wider than the diameter of the normal coronary artery in a patient with a length of over 20 mm or greater than one-third of the vessel. CAE can be further subdivided into diffuse and focal dilations by the number and the length of the dilated vessels. Histologically, it presents with extensive destruction of musculoelastic elements, marked degradation of collagen and elastic fibers, and disruption of the elastic lamina. Conversely, CAA is a focal lesion manifesting as focal dilatation, which can be fusiform (if the longitudinal diameter is greater than the transverse) or saccular (if the longitudinal diameter is smaller than the transverse). Giant CAA is defined as a 4-fold enlargement of the vessel diameter and is observed in only 0.02% of patients after coronary. An aneurysmal lesion can be either single or multiple. It can be either a congenital or acquired phenomenon. The pathophysiological mechanisms responsible for the formation of CAAE are not well understood. Atherosclerosis is the most common etiology of CAAE in adults, while Kawasaki disease is the most common in children. Other etiological factors include systemic connective tissue diseases, infectious diseases, vasculitis, congenital anomalies, genetic factors, and idiopathic CAA. Invasive assessment of CAAE is based on coronary angiography. Coronary computed tomography (CT) is a noninvasive method that enables accurate evaluation of aneurysm size and location. The most common complications are coronary spasm, local thrombosis, distal embolization, coronary artery rupture, and compression of adjacent structures by giant coronary aneurysms. The approach to each patient with CAAE should depend on the severity of symptoms, anatomical structure, size, and location of the aneurysm. Treatment methods should be carefully considered to avoid possible complications of CAAE. Simultaneously, we should not unnecessarily expose the patient to the risk of intervention or surgical treatment. Patients can be offered conservative or invasive treatment. However, there are still numerous controversies and ambiguities regarding the etiology, prognosis, and treatment of patients with coronary artery aneurysms. This study summarizes the current knowledge about this disease’s etiology, pathogenesis, and management. Full article

Optimal myocardial reperfusion during primary percutaneous coronary intervention (pPCI) is increasingly recognized to be beyond restoring epicardial coronary flow. Both invasive and non-invasive tools have highlighted the limitation of using this metric, and more efforts are focused towards achieving optimal reperfusion at the level of the microcirculation. Recent data highlighted the close relationship between thrombus burden and impaired microcirculation in patients presenting with ST-segment elevation myocardial infarction (STEMI). Moreover, distal embolization was an independent predictor of mortality in patients with STEMI. Likewise, the development of no-reflow phenomenon has been directly linked with worse clinical outcomes. Adjunctive thrombus aspiration during pPCI is intuitively intended to remove atherothrombotic material to mitigate the risk of distal embolization and the no-reflow phenomenon (NRP). However, prior trials on the use of thrombectomy during pPCI did not support its routine use, with comparable clinical endpoints to patients who underwent PCI alone. This article aims to review the existing literature highlighting the limitation on the use of thrombectomy and provide future insights into trials investigating the role of thrombectomy in contemporary pPCI. Full article

Background: Iatrogenic distal coronary artery perforation can be a life-threatening complication. While there are different dedicated devices for the embolization of distal perforations, there are scarce data about the embolization using the fragmented balloon catheter, the so-called cut balloon technique (CBT). Methods: We included consecutive patients with distal coronary perforations treated with CBT in four cardiac centers between 2017 and 2023. Clinical, angiographic and procedural characteristics as well as in-hospital outcomes were recorded. Results: Twenty-six patients (68% men, mean age: 71 ± 10.6 years) with 25 distal coronary perforations and one septal collateral perforation were included. Eleven patients (42%) had elective percutaneous coronary intervention, while fifteen patients (58%) were treated for acute coronary syndrome. The site of perforation was most frequently distributed in the left anterior descending artery (40%), followed by the circumflex artery (28%) and right coronary artery (24%). The diameter of balloons for CBT ranged from 1.5 to 4.0 mm, with most balloons (76%) being either 2.0 or 2.5 mm in diameter. Most balloons (88%) were previously used for lesion predilatation. The numbers of cut balloons needed to seal the perforation were 1, 2 and ≥3 in 48%, 20% and 32% of cases, respectively. The in-hospital prognosis was favorable, with cardiac tamponade requiring pericardiocentesis in only four (16%) patients. Neither emergency surgery nor cardiac death occurred. Conclusions: CBT is a safe, efficient and easy-to-implement technique for the embolization of coronary perforations. Most distal coronary perforations can be sealed with one or two fragments of cut balloons, obviating the need for additional devices. Full article

The use of saphenous vein grafts (SVGs) in the surgical management of obstructive coronary artery disease remains high despite a growing understanding of their limitations in longevity. In contemporary practice, approximately 95% of patients receive one SVG in addition to a left internal mammary artery (LIMA) graft. The precise patency rates for SVGs vary widely in the literature, with estimates of up to 61% failure rate at greater than 10 years of follow-up. SVGs are known to progressively degenerate over time and, even if they remain patent, demonstrate marked accelerated atherosclerosis. Multiple studies have demonstrated a marked acceleration of atherosclerosis in bypassed native coronary arteries compared to non-bypassed arteries, which predisposes to a high number of native chronic total occlusions (CTOs) and subsequent procedural challenges when managing graft failure. Patients with failing SVGs frequently require revascularisation to previously grafted territories, with estimates of 13% of CABG patients requiring an additional revascularisation procedure within 10 years. Redo CABG confers a significantly higher risk of in-hospital mortality and, as such, percutaneous coronary intervention (PCI) has become the favoured strategy for revascularisation in SVG failure. Percutaneous treatment of a degenerative SVG provides unique challenges secondary to a tendency for frequent superimposed thrombi on critical graft stenoses, friable lesions with marked potential for distal embolization and subsequent no-reflow phenomena, and high rates of peri-procedural myocardial infarction (MI). Furthermore, the rates of restenosis within SVG stents are disproportionately higher than native vessel PCI despite the advances in drug-eluting stent (DES) technology. The alternative to SVG PCI in failed grafts is PCI to the native vessel, ‘replacing’ the grafts and restoring patency within the previously grafted coronary artery, with or without occluding the donor graft. This strategy has additional challenges to de novo coronary artery PCI, however, due to the high burden of complex atherosclerotic lesion morphology, extensive coronary calcification, and the high incidence of CTO. Large patient cohort studies have reported worse short- and long-term outcomes with SVG PCI compared to native vessel PCI. The PROCTOR trial is a large and randomised control trial aimed at assessing the superiority of native vessel PCI versus vein graft PCI in patients with prior CABG awaiting results. This review article will explore the complexities of SVG failure and assess the contemporary evidence in guiding optimum percutaneous interventional strategy. Full article

Background: Direct stenting (DS) compared with conventional stenting (CS) after balloon predilatation may reduce distal embolization during percutaneous coronary intervention (PCI), thereby improving tissue reperfusion. In contrast, DS may increase the risk of stent underexpansion and target lesion failure. Methods: In this sub-study of the randomized COMPARE CRUSH trial (NCT03296540), we reviewed the efficacy of DS versus CS in a cohort of contemporary, pretreated ST-segment elevation myocardial infarction (STEMI) patients undergoing primary PCI. We compared DS versus CS, assessing (1) stent diameter in the culprit lesion, (2) thrombolysis in myocardial infarction (TIMI) flow in the infarct-related artery post-PCI and complete ST-segment resolution (STR) one-hour post-PCI, and (3) target lesion failure at one year. For proportional variables, propensity score weighting was applied to account for potential treatment selection bias. Results: This prespecified sub-study included 446 patients, of whom 189 (42%) were treated with DS. Stent diameters were comparable between groups (3.2 ± 0.5 vs. 3.2 ± 0.5 mm, p = 0.17). Post-PCI TIMI 3 flow and complete STR post-PCI rates were similar between groups (DS 93% vs. CS 90%, adjusted OR 1.16 [95% CI, 0.56–2.39], p = 0.69, and DS 72% vs. CS 58%, adjusted OR 1.29 [95% CI 0.77–2.16], p = 0.34, respectively). Moreover, target lesion failure rates at one year were comparable (DS 2% vs. 1%, adjusted OR 2.93 [95% CI 0.52–16.49], p = 0.22). Conclusion: In this contemporary pretreated STEMI cohort, we found no difference in early myocardial reperfusion outcomes between DS and CS. Moreover, DS seemed comparable to CS in terms of stent diameter and one-year vessel patency. Full article

Coronary no-reflow (CNR) is a frequent phenomenon that develops in patients with ST-segment elevation myocardial infarction (STEMI) following reperfusion therapy. CNR is highly dynamic, develops gradually (over hours) and persists for days to weeks after reperfusion. Microvascular obstruction (MVO) developing as a consequence of myocardial ischemia, distal embolization and reperfusion-related injury is the main pathophysiological mechanism of CNR. The frequency of CNR or MVO after primary PCI differs widely depending on the sensitivity of the tools used for diagnosis and timing of examination. Coronary angiography is readily available and most convenient to diagnose CNR but it is highly conservative and underestimates the true frequency of CNR. Cardiac magnetic resonance (CMR) imaging is the most sensitive method to diagnose MVO and CNR that provides information on the presence, localization and extent of MVO. CMR imaging detects intramyocardial hemorrhage and accurately estimates the infarct size. MVO and CNR markedly negate the benefits of reperfusion therapy and contribute to poor clinical outcomes including adverse remodeling of left ventricle, worsening or new congestive heart failure and reduced survival. Despite extensive research and the use of therapies that target almost all known pathophysiological mechanisms of CNR, no therapy has been found that prevents or reverses CNR and provides consistent clinical benefit in patients with STEMI undergoing reperfusion. Currently, the prevention or alleviation of MVO and CNR remain unmet goals in the therapy of STEMI that continue to be under intense research. Full article

In patients undergoing percutaneous coronary intervention, the second-generation drug-eluting stents (DES) are considered the gold standard of care for revascularization. By reducing neointimal hyperplasia, drug-eluting coronary stents decrease the need for repeat revascularizations compared with conventional coronary stents without an antiproliferative drug coating. It is important to note that early-generation DESs were associated with an increased risk of very late stent thrombosis, most likely due to delayed endothelialization or a delayed hypersensitivity reaction to the polymer. Studies have shown a lower risk of very late stent thrombosis with developing second-generation DESs with biocompatible and biodegradable polymers or without polymers altogether. In addition, research has indicated that thinner struts are associated with a reduced risk of intrastent restenosis and angiographic and clinical results. A DES with ultrathin struts (strut thickness of 70 µm) is more flexible, facilitates better tracking, and is more crossable than a conventional second-generation DES. The question is whether ultrathin eluting drug stents suit all kinds of lesions. Several authors have reported that improved coverage with less thrombus protrusion reduced the risk of distal embolization in patients with ST-elevation myocardial infarction (STEMI). Others have described that an ultrathin stent might recoil due to low radial strength. This could lead to residual stenosis and repeated revascularization of the artery. In CTO patients, the ultrathin stent failed to prove non-inferiority regarding in-segment late lumen loss and showed statistically higher rates of restenosis. Ultrathin-strut DESs with biodegradable polymers have limitations when treating calcified (or ostial) lesions and CTOs. However, they also possess certain advantages regarding deliverability (tight stenosis, tortuous lesions, high angulation, etc.), ease of use in bifurcation lesions, better endothelialization and vascular healing, and reducing stent thrombosis risk. In light of this, ultrathin-strut stents present a promising alternative to existing DESs of the second and third generation. The aims of the study are to compare ultrathin eluting stents with second- and third-generation conventional stents regarding procedural performance and outcomes based on different lesion types and specific populations. Full article

Coronary artery aneurysm (CAA) presenting as an ST-elevation myocardial infarction (STEMI) represents a clinical challenge due to the technical difficulties in the percutaneous management of this specific situation. Appropriate treatment for CAA depends on the precise clinical situation and consists of medical management, surgical resection, or/and stent placement. The high rate of complications during percutaneous intervention (distal thrombus embolization, no-reflow phenomenon, stent malposition, or dissection) makes emergent surgery a frequent situation in these cases. We present the case of a 50-year-old man with a STEMI due to thrombotic occlusion of CAA. Specific angiographic techniques and intracoronary imaging help with the percutaneous management of acute thrombotic occlusions in CAA, providing a less invasive approach than emergent surgery. Full article