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Invasive functional assessment of MINOCA. MINOCA, myocardial infarction with non-obstructive coronary arteries; CAD, coronary artery disease; FFR, fractional flow reserve; NHPR, non-hyperaemic pressure ratios; CFR, coronary flow reserve; IMR, index of microvascular resistance.
Source publication
Myocardial infarction with non-obstructive coronary arteries (MINOCA) encompasses several pathophysiological mechanisms not yet fully understood. Among the latter, vasomotion abnormalities and coronary microvascular dysfunction (CMD) play a major role for both epidemiological and prognostic reasons. Despite current guidelines do not recommend routi...
Citations
... Tuy nhiên, số lượng bằng chứng liên quan đến đo lưu lượng và lưu lượng dữ trữ mạch vành cũng như vai trò và tác động lâm sàng trên bệnh nhân MINOCA hiện còn hạn chế và chưa được thiết lập [69]. ...
Nhồi máu cơ tim (NMCT) không có tắc nghẽn động mạch vành (Myocardial infarction with non - obstructive coronary arteries - MINOCA) là một thể bệnh của NMCT do nhiều nguyên nhân khác nhau, bao gồm do xơ vữa động mạch (vỡ mảng bám) và không do xơ vữa (bóc tách động mạch vành, co thắt động mạch vành, thuyên tắc động mạch vành, rối loạn chức năng vi mạch vành và mất cân bằng cung cầu oxy cơ tim) dẫn đến tổn thương cơ tim mà không phải do bệnh động mạch vành tắc nghẽn. Chẩn đoán MINOCA được thực hiện trong quá trình chụp động mạch vành sau NMCT cấp, trong đó không có hẹp ≥ 50% ở động mạch vành thủ phạm và không có bệnh lý hệ thống rõ ràng để giải thích cho biểu hiện sàng này. Tỷ lệ lưu hành của MINOCA dao động từ 1% đến 14% ở tất cả các trường hợp NMCT. Tiên lượng rất khác nhau, tùy thuộc vào nguyên nhân của MINOCA. Việc thất bại trong xác định nguyên nhân của MINOCA có thể dẫn đến việc điều trị cho những bệnh nhân này không được đầy đủ và phù hợp. Nguyên tắc chính trong việc quản lý hội chứng này là làm rõ các cơ chế bệnh sinh nhằm cá thể hóa điều trị. Bài tổng quan này nhằm nêu lên các hướng dẫn hiện tại về chẩn đoán và điều trị trên bệnh nhân MINOCA Abstract Myocardial infarction with non - obstructive coronary arteries (MINOCA) is a form of myocardial infarction with different causes, including atherosclerotic (coronary plaque disruption) and nonatherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and myocardial supply - demand mismatch) resulting in myocardial damage that is not due to obstructive coronary artery disease. The diagnosis of MINOCA is made during coronary angiography following acute MI, where there is no stenosis ≥ 50% present in an infarct - related epicardial artery and no overt systemic aetiology for the presentation. Its prevalence ranges between 1% and 14% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient - specific treatments. This overview aims to highlight current guidelines on diagnosis and treatment in MINOCA patients.
... Among others, these mechanisms include plaque activation, coronary embolism, spasm, spontaneous coronary dissection, inflammatory or infiltrative processes; a further peculiar entity sometimes included in MINOCA is represented by takotsubo syndrome [2]. In many of these clinical situations, alterations of the coronary microvascular function are considered to be a key player in determining myocardial injury [4]; nevertheless, due to the difficulty of assessing coronary microvascular function, conclusive studies on the association of coronary microvascular dysfunction (CMD) with MINOCA are lacking. However, recently novel angiography-based methods to assess CMD in all three coronary vessels have emerged [5][6][7]; these techniques may shed light into the pathophysiology of MINOCA, especially in forms with localized myocardial injury, similarly to what our group showed for patients with localized forms of stable ischemia with no obstructive coronary artery disease (INOCA) [5]. ...
... MINOCA, i.e., MI without significant obstructive coronary artery disease, is a frequent phenomenon in the cath laboratory and accounts for 5-7% of all MIs [3]. Its pathogenesis is still incompletely understood, but dysregulations in the function of the coronary microvasculature are suggested as a possible mechanism leading to this acute ischemia [4]. The role of CMD in MINOCA is, however, still poorly investigated, as measurements of the microvascular function normally require wire advancement and drug administration, increasing procedure duration and cost; furthermore, this invasive diagnostic modality may bear risks for the patients (especially in the setting of acute coronary syndromes). ...
Introduction
Myocardial infarction without obstructive coronary artery disease (MINOCA) is a heterogeneous clinical condition presenting with myocardial necrosis not due to an obstruction of a major coronary artery. Recently, a relevant role of coronary microvascular dysfunction (CMD) in the pathogenesis of MINOCA has been suggested; however, data on this are scarce. Particularly, it is unclear if CMD is equally present in all subtypes of MINOCA or differentially identifies one or more of these conditions. Therefore, the aim of this study was to assess CMD in all three coronary vessels of MINOCA patients, relating it with the clinical subtype.
Methods
We retrospectively assessed coronary microvascular function in all three coronary territories by means of angiography-based index of microvascular resistance (aIMR) in 92 patients (64 with working diagnosis of MINOCA, 28 control patients). To further assess the association of CMD with MINOCA subtypes, MINOCA patients were subdivided according to clinical data in coronary cause (n = 13), takotsubo (n = 13), infiltrative or inflammatory cardiomyopathy (n = 9) or unclear (n = 29).
Results
Patients with working diagnosis of MINOCA showed a significantly elevated average aIMR compared to control patients (30.5 ± 7.6 vs. 22.1 ± 5.9, p < 0.001) as a marker of a relevant CMD; these data were consistent in all vessels. Among MINOCA subtypes, no significant difference in average aIMR could be detected between patients with coronary cause (33.2 ± 6.6), takotsubo cardiomyopathy (29.2 ± 6.9), infiltrative or inflammatory cardiomyopathy (28.1 ± 6.8) or unclear cause (30.6 ± 8.5; p = 0.412). Interestingly, aIMR was significantly elevated in the coronary vessel supplying the diseased myocardium compared with other vessels (31.9 ± 11.4 vs. 27.8 ± 8.2, p = 0.049).
Conclusion
Coronary microvascular dysfunction is a hallmark of all MINOCA subtypes. This study adds to the pathophysiological understanding of MINOCA and sheds light into the role of CMD in MINOCA.
... While both compartments (epicardial and microvascular) contribute to the pathogenesis of MINOCA, there is intense talk recently with regard to the involvement of the microvascular compartment in clinical outcomes. Robust evidence supports a likely interplay of vasomotor defects and CMD in the pathophysiology, as well as the prognosis of MINOCA [5,13]. Although multiple diagnostic approaches have been elucidated to unravel the role of other underlying etiologies of MINOCA, there are still significant gaps in our present knowledge of the assessment of coronary microcirculation after MINOCA. ...
In the past decade, scientific and clinical research has provided a translational perspective on myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA). MINOCA is characterized by clinical documentation of an acute MI but angiography shows no significant coronary artery obstruction (stenosis <50%). The prevalence of MINOCA is estimated to range from approximately 6 to 10% among MI patients, and those with this condition have a poor prognosis, experiencing high rates of mortality, rehospitalization, and socioeconomic burden. MINOCA represents a major unmet need in cardiovascular medicine, with uncertain clinical management. It is a complex condition that can be caused by various factors, including atherosclerosis, plaque rupture, coronary vasospasm, and microvascular dysfunction. Effective management of MINOCA depends on identifying the underlying mechanism of the infarction, thus a systematic diagnostic approach is recommended. Contemporary data shows that a significant number of patients exhibit structural and functional abnormalities in coronary microcirculation, which is referred to as coronary microvascular dysfunction (CMD). CMD plays a crucial role in patients with signs and symptoms of myocardial ischemia and non-obstructive coronary artery stenosis, including MINOCA. Furthermore, conducting a thorough evaluation of coronary function can have significant prognostic and therapeutic implications, since personalized patient management strategies based on this assessment have been shown to improve symptoms and prognosis. Therefore, an accurate and timely diagnosis of CMD is essential for effective patient management, which can be achieved through various invasive and non-invasive methods. This review will discuss the pathophysiological understanding, current diagnostic techniques, and management strategies of patients with MINOCA and CMD.
... Myocardial infarction with non-obstructive coronary artery disease (MINOCA) has been described as a puzzling entity with multiple underlying mechanisms, including both epicardial and microvascular causes [84]. Therefore, the recently standardized diagnostic work-up for MINOCA suggested by the scientific statement of the American Heart Association assigned intravascular imaging a central role, particularly when plaque disruption, SCAD, or coronary thrombus/emboli are suspected [85]. ...
Since its ability to precisely characterized atherosclerotic plaque phenotypes, to tailor stent implantation, as well as to guide both complex percutaneous coronary interventions (PCI) and invasive diagnostic work-ups (e.g., spontaneous coronary dissections or myocardial infarction with non-obstructive arteries), the adoption of optical coherence tomography (OCT) was raised in the past decades in order to provide complementary information to the traditional angiography and to overcome its limitations. However, the impact of OCT on daily clinical practice is currently modest, firstly because of the lack of both standardized algorithms of PCI guidance and data from prospective clinical trials. Therefore, the aim of our narrative review is to provide a comprehensive overview of the basic OCT interpretation, to summarize the evidence supporting the OCT guidance procedures and applications, to discuss its current limitations, and to highlight the knowledge gaps that need to be filled with more robust evidence.
... Coronary microvascular dysfunction stems from impaired vasodilation, increased vasoconstriction, and abnormal remodeling of microcirculation, which alters the coronary flow reserve (CFR) in the absence of epicardial obstructive disease (76). Coronary microvascular dysfunction is often underdiagnosed because it requires invasive functional tests (77). The majority of studies assessing coronary microvascular dysfunction have been completed among patients with ischemia with no obstructive coronary arteries (INOCA), with a prevalence of up to 41% (78). ...
... CFR is assessed by the thermodilution or doppler flow velocity method in a hyperemic state using adenosine. CFR <2.0 is used to diagnose non-endothelial-dependent coronary microvascular dysfunction (77). Index of microvascular resistance (IMR) is another useful technique to assess coronary microvascular dysfunction by thermodilution with >25 used as the cut-off but is associated with lower sensitivity and specificity than CFR. ...
Myocardial infarction with non-obstructive coronary arteries (MINOCA) is evident in up to 15% of all acute myocardial infarctions (AMI) and disproportionally affects females. Despite younger age, female predominance, and fewer cardiovascular risk factors, MINOCA patients have a worse prognosis than patients without cardiovascular disease and a similar prognosis compared to patients with MI and obstructive coronary artery disease (CAD). MINOCA is a syndrome with a broad differential diagnosis that includes both ischemic [coronary artery plaque disruption, coronary vasospasm, coronary microvascular dysfunction, spontaneous coronary artery dissection (SCAD), and coronary embolism/thrombosis] and non-ischemic mechanisms (Takotsubo cardiomyopathy, myocarditis, and non-ischemic cardiomyopathy)—the latter called MINOCA mimickers. Therefore, a standardized approach that includes multimodality imaging, such as coronary intravascular imaging, cardiac magnetic resonance, and in selected cases, coronary reactivity testing, including provocation testing for coronary vasospasm, is necessary to determine underlying etiology and direct treatment. Herein, we review the prevalence, characteristics, prognosis, diagnosis, and treatment of MINOCA -a syndrome often overlooked.
... Although FFR has been traditionally considered an index of epicardial ischemia, it can be strongly influenced by the microvascular function and resistances, with a tendency toward an elevation of its values [40]. Nevertheless, in patients with microvascular dysfunction or myocardial infarction with non-obstructive coronary artery disease (MINOCA) and concomitant intermediate coronary lesions, FFR can help rule out type 1 MI epicardial ischemia [41,42]. ...
Simple visual estimation of coronary angiography is limited by several factors that can hinder the proper classification of coronary lesions. Fractional flow reserve (FFR) is the most widely used tool to perform a physiological evaluation of coronary stenoses. Compared to isolated angiography, FFR has been demonstrated to be more effective in selecting those lesions associated with myocardial ischemia and, accordingly, impaired outcomes. At the same time, deferring coronary intervention in those lesions that do not show ischemic FFR values has proven safe and not associated with adverse events. Despite a major randomized clinical trial (RCT) and several non-randomized studies showing that FFR-guided revascularization could be superior to isolated angiography in improving clinical outcomes, subsequent RCTs have reported conflicting results. In this review, we summarize the principles behind FFR and the data currently available in the literature, highlighting the main differences between randomized and non-randomized studies that investigated this topic.
... However, the body of evidence concerning coronary flow and flow reserve measurement among the MINOCA population is currently limited. Similarly, the role and the clinical implications of continuous thermodilution-derived indexes within MINOCA patients are not yet established [92]. ...
Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a heterogeneous group of conditions that include both atherosclerotic (coronary plaque disruption) and non-atherosclerotic (spontaneous coronary artery dissection, coronary artery spasm, coronary artery embolism, coronary microvascular dysfunction, and supply–demand mismatch) causes resulting in myocardial damage that is not due to obstructive coronary artery disease. Failure to identify the underlying cause may result in inadequate and inappropriate therapy in these patients. The cornerstone of managing MINOCA patients is to identify the underlying mechanism to achieve the target treatment. Intravascular imaging is able to identify different morphologic features of coronary plaques, while cardiac magnetic resonance is the gold standard for detection of myocardial infarction in the setting of MINOCA. In this review, we summarize the relevant clinical issues, contemporary diagnosis, and treatment options of MINOCA.
Introduction:
The pathophysiology of atherosclerosis and its acute complications, such as the Acute Coronary Syndromes (ACS), is continuously under investigation. Immunity and inflammation seem to play a pivotal role in promoting formation and grow of atherosclerotic plaques. At the same time, plaque rupture followed by both platelets' activation and coagulation cascade induction lead to intracoronary thrombus formation. Although these phenomena might be considered responsible of about 90% of ACS, in up to 5-10% of acute syndromes a non-obstructive coronary artery disease (MINOCA) might be documented. This paper gives an overview on athero-thrombosis and immuno-inflammation processes involved in ACS pathophysiology also emphasizing the pathological mechanisms potentially involved in MINOCA.
Areas covered:
The relationship between immuno-inflammation and atherothrombosis is continuously updated by recent findings. At the same time, pathophysiology of MINOCA still remains a partially unexplored field, stimulating the research of potential links between these two aspects of ACS pathophysiology.
Expert opinion:
Pathophysyiology of ACS has been extensively investigated; however, several grey areas still remain. MINOCA represents one of these areas. At the same time, many aspects of immune-inflammation processes are still unknown. Thus, research should be continued to shed a brighter light on both these sides of "ACS" moon.
