Long-term prognosis of patients presenting with ST-segment elevation myocardial infarction with no significant coronary artery disease (from the HORIZONS-AMI trial)

Intravascular imaging in the diagnosis and management of patients with suspected intracoronary pathologies: A CJC White Paper

Intravascular imaging has become an integral part of the diagnostic and management strategies for intracoronary pathologies. This White Paper summarizes current evidence and its implications on the use of intravascular imaging in interventional cardiology practice. The areas addressed are planning and optimization of percutaneous coronary intervention, management of stent failure, and evaluation of ambiguous coronary lesions and myocardial infarction with non-obstructive coronary disease (MINOCA). Findings are presented following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system in an expert consensus process involving a diverse Writing group and vetted by a Review group. Expert consensus was achieved around nine statements. Use of intravascular imaging in guiding percutaneous revascularization is supported by high quality evidence, particularly for lesions with increased risk of recurrent events or stent failure. Specific considerations for intravascular imaging guidance of intervention in left main lesions, chronic occlusion lesions as well as patients at high risk of contrast nephropathy are explored. Use of intravascular imaging to identify pathologies associated with stent failure and guide repeat intervention, resolve ambiguities in lesion assessment and establish diagnoses in patients presenting with MINOCA is supported by moderate to low quality evidence. Each topic is accompanied by clinical pointers to aid the practicing interventional cardiologist in implementation of the White paper findings. The findings of this White Paper will help to guide the utilization of intravascular imaging towards those situations in which the balance of efficacy, safety and cost are most optimal.

Sex differences in patients presenting with acute coronary syndrome: a state-of-the-art review

Cardiovascular conditions in the spectrum of acute coronary syndromes are characterized by sex differences with regard to pathophysiology, risk factors, clinical presentation, invasive and pharmacologic treatment, and outcomes. This review delves into these differences, including specific subsets like myocardial infarction with non-obstructed coronary arteries or Spontaneous Coronary Artery Dissection, and alternative diagnoses like Takotsubo cardiomyopathy or myocarditis. Moreover, practical considerations are enclosed, on how a sex-specific approach should be integrated in clinical practice: in fact, personal history should focus on female-specific risk factors, and hormonal status and hormonal therapy should be assessed. Moreover, physical and psychological stressors should be investigated, particularly in the event of Spontaneous Coronary Artery Dissection or Takotsubo cardiomyopathy.

Pathophysiology of Myocardial Infarction With Nonobstructive Coronary Artery Disease: A Contemporary Systematic Review

Background

Myocardial infarction with nonobstructive coronary artery disease (MINOCA) is defined as acute myocardial infarction (AMI) with angiographically nonobstructive coronary artery disease. MINOCA represents 6% of all AMI cases and is associated with increased mortality and morbidity. However, the wide array of pathophysiological factors and causes associated with MINOCA presents a diagnostic conundrum. Therefore, we conducted a contemporary systematic review of the pathophysiology of MINOCA.

Methods

A comprehensive systematic review of MINOCA was carried out through the utilization of the PubMed database. All systematic reviews, meta-analyses, randomized controlled trials, and cohort studies available in English or French that reported on the pathophysiology of MINOCA published after January 1, 2013 were retained.

Results

Of the 600 identified records, 80 records were retained. Central to the concept of MINOCA is the definition of AMI, characterized by the presence of myocardial damage reflected by elevated cardiac biomarkers in the setting of acute myocardial ischemia. As a result, a structured approach should be adopted to thoroughly assess and address clinically overlooked obstructive coronary artery disease, and cardiac and extracardiac mechanisms of myocyte injury. Once these options have been ruled out, a diagnosis of MINOCA can be established, and the appropriate multimodal assessment can be conducted to determine its specific underlying cause (plaque disruption, epicardial coronary vasospasm, coronary microvascular dysfunction, and coronary embolism and/or spontaneous coronary dissection or supply-demand mismatch).

Conclusions

Integrating a suitable definition of AMI and understanding the pathophysiological mechanisms of MINOCA are crucial to ensure an effective multimodal diagnostic evaluation and the provision of adequate tailored therapies.

Coronary microvascular dysfunction and myocardial infarction with non-obstructive coronary arteries: Where do we stand?

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.

Mortality in ST-Segment Elevation Myocardial Infarction With Nonobstructive Coronary Arteries and Mimickers

Importance

The clinical characteristics and prognosis of patients with ST-segment elevation myocardial infarction (STEMI) with nonobstructive coronaries (MINOCA) are largely unknown.

Objective

To assess differences in 5-year mortality in patients presenting with STEMI due to MINOCA and MINOCA mimickers as compared with obstructive disease.

Design, Setting, and Participants

A retrospective analysis of a prospective registry-based cohort study of consecutive STEMI activations at 3 regional Midwest STEMI programs. STEMI without a culprit artery and elevated troponin levels were categorized as MINOCA (absence of coronary artery stenosis >50% and confirmed or suspected coronary artery plaque disruption, epicardial coronary spasm, or coronary embolism/thrombosis) or MINOCA mimickers (takotsubo cardiomyopathy, myocarditis, or nonischemic cardiomyopathy). Data were analyzed from March 2003 to December 2020.

Main Outcomes and Measures

Adjusted Cox regression analysis was used to assess 5-year mortality risk in STEMI presenting with MINOCA and MINOCA mimickers in comparison with obstructive disease.

Results

Among 8560 consecutive patients with STEMI, mean (SD) age was 62 (14) years, 30% were female (2609 participants), and 94% were non-Hispanic White (4358 participants). The cohort included 8151 patients with STEMI due to obstructive disease (95.2%), 120 patients with MINOCA (1.4%), and 289 patients with MINOCA mimickers (3.8%). Patients were followed up for a median (IQR) of 7.1 (3.6-10.7) years. Patients with MINOCA and MINOCA mimickers were less likely to be discharged with cardiac medications compared with obstructive disease. At 5-year follow-up, mortality in STEMI presenting with obstructive disease (1228 participants [16%]) was similar to MINOCA (20 participants [18%]; χ21 = 1.1; log-rank P = .29) and MINOCA mimickers (52 participants [18%]; χ21 = 2.3; log-rank P = .13). In adjusted Cox regression analysis compared with obstructive disease, the 5-year mortality hazard risk was 1.93 times higher in MINOCA (95% CI, 1.06-3.53) and similar in MINOCA mimickers (HR, 1.08; 95% CI, 0.79-1.49).

Conclusions and Relevance

In this large multicenter cohort study of consecutive clinical patients with STEMI, presenting with MINOCA was associated with a higher risk of mortality than obstructive disease; the risk of mortality was similar in patients with MINOCA mimickers and obstructive disease. Further investigation is necessary to understand the pathophysiologic mechanisms involved in this high-risk STEMI population.

Coronary Vascular (DYS) Function and Invasive Physiology Assessment: Insights into Bolus and Continuous Thermodilution Methods

A considerable number of patients with angina or myocardial ischemia have no significant coronary artery disease on invasive angiography. In recent years, several steps towards a better comprehension of the pathophysiology of these conditions, angina or ischemia with non-obstructive coronary arteries (ANOCA/INOCA), have been made. Nevertheless, several gaps in knowledge still remain. This review is intended to provide a comprehensive overview of ANOCA and INOCA, with a particular focus on pathophysiology, recent diagnostic innovations, gaps in knowledge and treatment modalities.

Non-invasive coronary flow velocity reserve assessment predicts adverse outcome in women with unstable angina without obstructive coronary artery stenosis

Background

Evaluation of coronary flow velocity reserve (CFVR) is the physiological approach to assess the severity of coronary stenosis and microvascular dysfunction. Impaired CFVR occurs frequently in women with suspected or known coronary artery disease. The aim of this study was to assess the role of CFVR to predict long-term cardiovascular event rate in women with unstable angina (UA) without obstructive coronary artery stenosis.

Methods

CFVR in left anterior descending coronary artery was assessed by adenosine transthoracic echocardiograhy in 161 women admitted at our Department with UA and without obstructive coronary artery disease.

Results

During a mean FU of 32.5 ± 19.6 months, 53 cardiac events occurred: 6 nonfatal acute myocardial infarction, 22 UA, 7 coronary revascularization by percutaneous transluminal coronary angioplasty, 1 coronary bypass surgery, 3 ischemic stroke, and 8 episodes of congestive heart failure with preserved ejection fraction and 6 cardiac deaths. Using a ROC curve analysis, CFVR 2.14 was the best predictor of cardiac events and was considered as abnormal CFVR. Abnormal CFVR was associated with lower cardiac event-free survival (30 vs 80%, p < 0.0001). During FU, 70% of women with reduced CFVR had cardiac events whereas only 20% with normal CFVR (p = 0.0001). At multivariate Cox analysis, smoke habitus (p = 0.003), metabolic syndrome (p = 0.01), and CFVR (p < 0.0001) were significantly associated with cardiac events at FU.

Conclusion

Noninvasive CFVR provides an independent predictor of cardiovascular prognosis information in women with UA without obstructive coronary artery disease whereas, impaired CFVR seems to be associated with higher CV events at FU.

Characteristics and Long-term Mortality in Patients with ST-Segment Elevation Myocardial Infarction with Non-Obstructive Coronary Arteries (STE-MINOCA): A High Risk Cohort

Background

The prognosis of ST-segment elevation myocardial infarction with non-obstructive coronaries (STE-MINOCA) is largely unknown.

Methods

The objective of this study is to evaluate the prevalence, characteristics, and 5-year mortality of patients with STE-MINOCA compared to STEMI with coronary artery obstruction (STEMI-Obstruction) using a multicenter cohort of consecutive STEMI patients at 3 regional Midwest STEMI programs from 2003 to 2020. STE-MINOCA was defined based on (1) coronary stenosis < 60% by visual estimation, (2) ischemia with elevated troponin, and (3) no alternative diagnosis. STE-MINOCA was further classified based on American Heart Association (AHA) definition as AHA STE-MINOCA and AHA STE-MINOCA Mimicker.

Results

8,566 STEMI patients, including 420 (4.9%) STE-MINOCA (26.9% AHA STE-MINOCA and 73.1% AHA STE-MINOCA Mimicker) were followed for a median of 7.1 years. Compared to STEMI-Obstruction, STE-MINOCA were younger, more often female, had fewer cardiovascular risk factors, and were less likely to be discharged on cardiac medications. At five years, mortality was higher in STE-MINOCA compared with STEMI-Obstruction (18% vs. 15%, p=0.033). In propensity score-matched analysis, STE-MINOCA had a 1.4-fold (95% CI: 1.04-1.89, p=0.028) higher risk of 5-year all-cause mortality compared with STEMI-Obstruction. Furthermore, 5-year mortality risk was significantly higher in AHA STE-MINOCA Mimicker (19% vs. 15%, p=0.043) but similar in AHA STE-MINOCA (17% vs. 15%, p=0.42) compared with STEMI-Obstruction.

Conclusions

In this large multicenter STEMI cohort, nearly 5% of patients presented with STE-MINOCA. At five years, mortality approached 20% among patients with STE-MINOCA. Despite the lower risk profile, STE-MINOCA patients were at 40% higher risk of 5-year all-cause mortality compared with STEMI-Obstruction. Additionally, 5-year all-cause mortality risk was higher in AHA STE-MINOCA Mimicker but similar in AHA STE-MINOCA compared to STEMI-Obstruction.

Myocardial infarction with non-obstructive coronary arteries (MINOCA)

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.

Myocardial bridging is significantly associated to myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a common disorder characterized by the presence of clinical criteria for acute myocardial infarction in the absence of obstructive coronary artery disease on angiography. We aim to investigate the relationship between myocardial bridging (MB) and MINOCA.

METHODS AND RESULTS

An observational retrospective study was conducted on 15 036 patients who had been referred for coronary angiography and who fulfilled the Fourth Universal Definition of Myocardial Infarction. The study population was divided into ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients, from which we defined two main groups: the MINOCA group and the coronary artery disease (CAD) group. Statistical analyses were carried out by using SPSS, version 20. The prevalence of angiographic MB among the groups was significantly greater in the MINOCA group (2.9% vs. 0.8%). MINOCA accounted for 14.5% of spontaneous myocardial infarction, and the clinical presentation was more frequently NSTEMI rather than STEMI (84.3% vs. 15.7%). After adjusting for confounders, multivariate analyses showed a positive association between MB and MINOCA [odds ratio = 3.28, 95% CI (2.34; 4.61) P < 0.001]. Cardiovascular risk factors were less common in the MINOCA population, which was younger and more often female.

CONCLUSION

MB is a risk factor for MINOCA. Because MB prevalence differed significantly between the controls (CAD group) and cases (MINOCA group), which were positively associated to MB, it seems likely that MB would be a potential cause of MINOCA. Investigations for MB in MINOCA cases and especially in NSTEMI patients seem necessary.

Cardiac rehabilitation in women, challenges and opportunities

Cardiac rehabilitation(CR) has known proven benefits in reducing mortality related to cardiovascular disease (CVD), improving quality of life (QoL), and preventing CVD-related readmissions. Despite these known benefits, CR remains underutilized among women relative to men. Disparities exist at the level of referral, enrollment, and program completion. Much is left to be understood regarding the utility of CR in female-predominant CVD such as postpartum cardiomyopathy and Spontaneous Coronary Artery Dissection. This review identifies the benefits of CR for specific populations of women and elucidates on the barriers to CR. We also describe current recommendations to overcome barriers to CR in women.

The evolving role of cardiac imaging in patients with myocardial infarction and non-obstructive coronary arteries

Myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA) represents a heterogeneous clinical conundrum accounting for about 6%-8% of all acute MI who are referred for coronary angiography. Current guidelines and consensus documents recommend that these patients are appropriately diagnosed, uncovering the causes of MINOCA, so that specific therapies can be prescribed. Indeed, there are a variety of causes that can result in this clinical condition, and for this reason diagnostic cardiac imaging has an emerging critical role in the assessment of patients with suspected or confirmed MINOCA. In last years, different cardiac imaging techniques have been evaluated in this context, and the comprehension of their strengths and limitations is of the utmost importance for their effective use in clinical practice. Moreover, recent evidence is clearly suggesting that a multimodality cardiac imaging approach, combining different techniques, seems to be crucial for a proper management of MINOCA. However, great variability still exists in clinical practice in the management of patients with suspected MINOCA, also depending on the availability of diagnostic tools and local expertise. Herein, we review the current knowledge supporting the use of different cardiac imaging techniques in patients with MINOCA, underscoring the importance of a comprehensive multimodality cardiac imaging approach and proposing a practical diagnostic algorithm to properly identify and treat the specific causes of MINOCA, in order to improve prognosis and the quality of life in these patients.

Prognostic value of statin therapy in patients with myocardial infarction with nonobstructive coronary arteries (MINOCA): a meta-analysis

BACKGROUND

Given the complex aetiology and a limited amount of evidence, the medical treatment (including statin use) of myocardial infarction with non-obstructive coronary artery disease (MINOCA) remains uncertain. The objective of the present study was to evaluate the effect of statin therapy on major cardiovascular events (MACE) and mortality in MINOCA patients.

METHODS

A systematic review and meta-analysis of time-to-event outcomes were performed of studies of statin therapy on MINOCA patients, reporting data from MACE or mortality, after searching the PubMed/MEDLINE, Embase, Science Direct, Scopus, Google Scholar, and Cochrane databases. A fixed-effects meta-analysis model was then applied.

RESULTS

Six observational studies of statin therapy on MINOCA, involving a total of 11,171 patients, were identified and considered eligible for analysis (9129 subjects received statin therapy while 2042 patients were part of the respective control arms). Quantitative analysis (5 studies were included) showed that statin use was associated with lower mortality (HR: 0.65; 95% CI: 0.56-0.75, I²: 0%). Also, the meta-analysis showed that statin therapy was associated with a lower incidence of MACE (HR: 0.78; 95% CI: 0.69-0.88, I²:27%).

CONCLUSION

Our data suggest that in a population with MINOCA, the use of statin therapy results in significant reduction on MACE and mortality. These results must be confirmed in future clinical trials.

Role of cardiovascular magnetic resonance in the prognosis of patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

It is estimated that 5% to 10% of patients with myocardial infarction (MI) present with no obstructive coronary artery lesions. Until now, most studies have focused on acute coronary syndrome, including different clinical entities with a similar presentation encompassed under the term MINOCA (MI with non-obstructive coronary arteries). The aim of this study is to assess the prognosis of patients diagnosed with true infarction, confirmed by cardiovascular magnetic resonance (CMR), in the absence of significant coronary lesions.

METHODS

Prospective multicenter registry study, including 120 consecutive patients with a CMR-confirmed MI without obstructive coronary artery lesions. The primary clinical outcome was major adverse cardiovascular events (MACE: death, non-fatal infarction, stroke, or cardiac readmission), assessed over three years.

RESULTS

Seventy-six patients (63.3%) were admitted with a diagnosis of acute coronary syndrome, and 44 (36.6%) for other causes (mainly heart failure); the definitive diagnosis was established by CMR. Most patients (64.2%) were men, and the mean age was 58.8 ± 13.5 years. Patients presented with small infarcts: 83 (69.1%) showed late gadolinium enhancement (LGE) in one or two myocardial segments, mainly transmural (in 77.5% of patients) and with a preserved left ventricular ejection fraction (median 54.8%, interquartile range 37-62). The most frequent infarct location was inferolateral (n = 38, 31.7%). During follow-up, 43 patients (35.8%) experienced a MACE, including 9 (7.5%) who died. In multivariable analysis, LGE in two versus one myocardial segment doubled the risk of adverse cardiac events (hazard ratio [HR] 2.32, 95% confidence interval [CI] 0.97-5.83, p = 0.058). Involvement of three or more myocardial segments almost tripled the risk (HR 2.71, 95% CI 1.04-7.04, p = 0.040 respectively).

CONCLUSIONS

Patients with true MI but without significant coronary artery lesions predominantly had small infarcts. Myocardial 3-segment LGE involvement is associated with a significantly higher risk of adverse cardiac events.

Lesion characteristics and prognosis of acute coronary syndrome without angiographically significant coronary artery stenosis

AIMS

While patients with acute coronary syndrome (ACS) presenting with non-obstructive coronary artery disease (CAD) are at high risk for cardiovascular mortality and morbidity, detailed lesion characteristics are unclear. The aim of this study was to investigate the lesion characteristics and prognosis of ACS with non-obstructive CAD.

METHODS AND RESULTS

This study consisted of 82 consecutive ACS patients without obstructive CAD who underwent optical coherence tomography (OCT). Based on the presence of high-risk lesions (HL) in the culprit artery, we classified the patients into two groups: HL group and non-high-risk lesions (NHL) group. A systematic clinical follow-up was performed at our outpatient clinic for up to 24 months. Our endpoint was recurrence of ACS with obstructive CAD. OCT revealed that 42 (51.2%) of 82 patients had hidden HL in the culprit artery, including ruptured plaque (15.9%), calcified nodule (11.0%), spontaneous coronary artery dissection (8.5%), lone thrombus (8.5%), thin-cap fibroatheroma (6.1%), and plaque erosion (1.2%). During angiography, 5 (11.9%) HL patients complained of chest pain without ST elevation. Patients in the HL group had poorer prognoses than those in the other groups (P = 0.040).

CONCLUSION

Hidden high-risk lesions accompany ACS patients without obstructive CAD, resulting in poorer outcomes. Vascular injury itself might provoke acute chest pain.

OCT Findings in MINOCA

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.

Intracoronary optical coherence tomography: state of the art and future directions

Optical coherence tomography (OCT) has been increasingly utilised to guide percutaneous coronary intervention (PCI). Despite the diagnostic utility of OCT, facilitated by its high resolution, the impact of intracoronary OCT on clinical practice has thus far been limited. Difficulty in transitioning from intravascular ultrasound (IVUS), complex image interpretation, lack of a standardised algorithm for PCI guidance, and paucity of data from prospective clinical trials have contributed to the modest adoption. Herein, we provide a comprehensive up-do-date overview on the utility of OCT in coronary artery disease, including technical details, device set-up, simplified OCT image interpretation, recognition of the imaging artefacts, and an algorithmic approach for using OCT in PCI guidance. We discuss the utility of OCT in acute coronary syndromes, provide a summary of the clinical trial data, list the work in progress, and discuss the future directions.

Prevalence, Clinical Factors, and Outcomes Associated With Myocardial Infarction With Nonobstructive Coronary Artery

BACKGROUND

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is an underrecognized clinical problem in patients presenting with acute coronary syndrome. Various clinical disorders lead to MINOCA thus making treatment and diagnosis a challenge. We aimed to compare the clinical factors and outcomes of patients with MINOCA versus obstructive disease [myocardial infarction due to coronary artery disease (MI-CAD)] in a largely rural health system.

METHODS

Between May 1, 2009 and June 24, 2019, all consecutive ST-segment elevation myocardial infarction patients at Essentia Health were prospectively examined. We categorized patients into MI-CAD (obstructive plaque ≥ 50% with revascularization) or MINOCA (obstructive plaque < 50% with exclusion of other alternative cause). Outcomes included 30-day and 1-year all-cause mortality, 30-day all-cause readmission and 30-day cardiac readmission.

RESULTS

There were 2170 patients included in the study; 2097 (96.6 %) had MI-CAD and 73 (3.4%) met the definition of MINOCA. Within the MINOCA group, the 3 most common presentations were supply-demand mismatch (28.8%), spontaneous coronary artery dissection (9.6%), and other etiology (60.3%). Only 10 (13 %) MINOCA patients had cardiac magnetic resonance imaging studies obtained within 6 months. MINOCA patients were younger 61.6 versus 63.4 years with higher left ventricular function 51.6% versus 50.4% with less likelihood of prior myocardial infarction 4.1% versus 15.5% or congestive heart failure 2.7% versus 6.3% (P < 0.05). Compared with MI-CAD patients, MINOCA patients had similar 30-day mortality (7.1% vs. 8.2%; P = 0.70), 1-year mortality (10.4% vs. 8.2 %; P = 0.55), and 30-day cardiac readmission (8.7% vs. 9.6%; P = 0.29). MINOCA patients were less likely to be discharged on aspirin, betablockers, angiotensin-converting enzyme inhibitor/angiotensin receptor blockers, or statins (P < 0.05).

CONCLUSION

Though there was no difference in readmission and mortality between MINOCA and MI-CAD; use of secondary prevention medications and cardiac rehabilitation referral was low in MINOCA patients. Prospective studies will be relevant to assess effective medical therapy to improve outcomes in MINOCA patients.

Review Article--Clinical Overview of Myocardial Infarction Without Obstructive Coronary Artey Disease (MINOCA)

The term myocardial infarction with non-obstructive coronary arteries (MINOCA) applies to patients who have clinical evidence of AMI but coronary angiography reveals no coronary obstructions and an alternative diagnosis is not possible. It is a heterogenous group of disease. Its prognosis, predictors of mortality and optimum management is unclear. In this review, we present a disease overview for MINOCA including the clinical features, adopted definitions, prevalence, diagnosis, treatment, and prognosis.

Myocardial Infarction with Nonobstructive Coronary Artery Disease—Definition, Etiopathogenesis, Diagnosis, and Management

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is a complex clinical syndrome that is characterized by evidence of acute myocardial infarction in the absence of significant epicardial coronary artery disease on angiography. The term “MINOCA” encompasses a group of heterogeneous diseases with varying underlying mechanisms and each with its own pathophysiology. Overlooked plaque rupture or erosion and coronary vasospasm are the most common causes of MINOCA and can be diagnosed by routine intracoronary imaging and vasoreactivity testing, respectively. Coronary microvascular dysfunction is a less recognized, albeit an important cause of morbidity in patients presenting with MINOCA. Although MINOCA is a rare presentation of acute coronary syndrome, it is not a benign disorder and can have adverse consequences if untreated. In this article, we aim to review the pathogenesis, clinical characteristics, and finally propose a systematic approach in the diagnosis and management of patients with MINOCA.

Clinical and electrocardiographic features of patients with myocardial infarction with non-obstructive coronary artery disease (MINOCA)

AIMS

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is often an underdiagnosed and undertreated condition. This study aimed to evaluate clinical and ECG characteristics of MINOCA in a large cohort of patients admitted for acute coronary syndrome.

METHODS

All coronary angiograms performed at the University Heart Center in Zurich (Switzerland) between 2012 and 2016 were investigated. MINOCA was defined according to European Society of Cardiology guidelines and patients were divided into two groups, based on the presence or absence of coronary sclerosis at angiogram[nonobstructive coronary artery disease (noCAD) and normal coronary arteries (NCA)]), after exclusion of myocarditis and Takotsubo syndrome.

RESULTS

Out of 13 669 angiographic studies, 3695 were diagnosed with acute coronary syndrome; of these, 244 patients presented MINOCA (6.6%). Patients with noCAD were more likely to be older (67.9 vs. 59.2 years, P < 0.001) with higher prevalence of traditional cardiovascular risk factors (hypertension 64.1 vs. 41.2%, P = 0.002; diabetes 19.7 vs. 10.8%, P = 0.036; hypercholesterolemia 36.6 vs. 23.5%, P = 0.037). On surface ECG, anterior ST- segment elevation was more frequent in NCA patients (13.7 vs. 5.0%, P = 0.016). Secondary prevention therapy was significantly more prescribed in noCAD compared with NCA patients (acetylsalicylic acid 68.3 vs. 21.6%, P less than 0.001; statins 76.1 vs. 22.5%, P less than 0.001; angiotensin-converting enzyme inhibitor-AT1 blockers 51.4 vs. 31.3%, P = 0.006). One-year mortality was very low (0.4% for noCAD patients).

CONCLUSION

noCAD patients were older, with higher prevalence of cardiovascular risk factors and more frequently discharged with secondary prevention therapy. NCA patients presented more frequently anterior ST- segment elevation. Further diagnostic tests should be highly recommended to determine the underlying mechanism of MINOCA.

Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Interventions

This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful imaging features to identify culprit and vulnerable coronary plaque, which offers the interventional cardiologist guidance on when to adopt an intracoronary imaging-guided approach to the treatment of coronary artery disease and provides an appraisal of intravascular imaging-derived metrics to define the haemodynamic significance of coronary lesions.

A review of diagnosis, etiology, assessment, and management of patients with myocardial infarction in the absence of obstructive coronary artery disease

Myocardial infarction (MI) in the absence of obstructive coronary artery disease (MINOCA) is prevalent in around 5% of acute myocardial infarction (AMI) presentations. MINOCA is a heterogeneous entity with many different etiologies. It is important for health care providers to familiarize themselves with the disease process, presentation, and possible underlying causes in order to guide appropriate management strategies. In this article, the authors review the contemporary definition, etiologies and assessment, and management for AMI patients with MINOCA.

Clinical Characteristics, Treatments, and Outcomes of Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA): Results from a Multicenter National Registry

BACKGROUND

Diagnosis of myocardial infarction with non-obstructive coronary arteries (MINOCA) requires both clinical evidence of acute myocardial infarction (AMI) and demonstration of non-obstructive coronary arteries using angiography. We compared the clinical features, treatments, and three-year outcomes in patients with MINOCA and myocardial infarction with obstructive coronary artery disease (MI-CAD).

METHODS

We retrospectively analyzed data for 205,606 hospitalized patients with AMI. MINOCA was indicated as a working diagnosis in 6063 patients (2.94% of all AMI patients). For the control group we included 160,886 patients with MI-CAD. We evaluated the baseline characteristics, medication management options, outcomes, and readmission causes at 36 months follow-up.

RESULTS

Patients in the MINOCA group were younger. Females constituted a greater proportion of patients in the MINOCA group when compared to MI-CAD patients. STEMI during admission was diagnosed less frequently in the MINOCA group when compared to the MI-CAD group. All-cause mortality at 12 months was higher in the MINOCA group (10.94% vs. 9.54%, p < 0.001). At 36 months, there was no difference in the all-cause mortality rates (MINOCA 16.18% vs. MI-CAD 14.93%, p = 0.081). All-cause readmission rates were lower in the MINOCA group when compared to the MI-CAD group at both 12 months (45.19% vs. 54.33%, p < 0.001) and 36 months follow-up (56.42% vs. 66.66%, p < 0.001).

CONCLUSIONS

This is the first description of the clinical features, treatments, and three-year outcomes in a large population of Polish patients. The main finding of this study was a relatively low rate of MINOCA, with high rates of adverse events both at 12 and 36 months follow-up.

Clinical Outcomes and Predictors of ST-Elevation Versus Non-ST-Elevation Myocardial Infarction with Non-Obstructive Coronary Arteries

BACKGROUND

Myocardial infarction with nonobstructive coronary arteries (MINOCA) can be clinically categorized as ST-segment elevation (STE) and non-ST-segment elevation (NSTE), whose clinical prognosis are poorly understood. The aim of this study was to compare the clinical outcome and their predictors of patients with STE and NSTE in MINOCA population.

METHODS

A total of 265 patients with MINOCA (102 with STE, and 163 with NSTE) were consecutively collected. Clinical profile, prognosis, and predictors of all patients were assessed.

RESULTS

The proportion of patients with NSTE was greater than patients with STE in MINOCA population. Patients with NSTE were older and more likely to be female and had a higher incidence of atrial fibrillation. Both high density lipoprotein (HDL) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were higher in the NSTE group. Patients with STE were more likely to have a history of smoking and a higher diastolic blood pressure. During the 1-year follow up, there were no differences in the outcomes between the STE and NSTE groups, with no significant differences in mortality and a similar rate of major adverse cardiovascular events (MACE) (20.9% vs 19.3%, P = 0.767). The multivariable predictors of MACE in the NSTE groups were age, lower level of total cholesterol, hypertension, and smoking history, whereas reduced left ventricular ejection fraction, and diabetes mellitus were the multivariable predictors of major adverse cardiac events in the STE group.

CONCLUSIONS

There were differences in the clinical profile between STE and NSTE in the MINOCA population, whereas the outcomes during the 1-year follow up were similar. The STE and NSTE groups had different predictive factors for major adverse cardiac events.

Diagnostic work-up and therapeutic implications in MINOCA: need for a personalized approach

Myocardial infarction with non-obstructive coronary artery (MINOCA) disease represents a heterogeneous clinical conundrum accounting for about 6% of all acute myocardial infarction (MI) cases. Initially believed to be a benign condition, is now becoming clear that MINOCA is associated with a non-negligible risk of mortality, rehospitalization, disability and angina burden at follow-up, with high socioeconomic costs. To date, there are no prospective clinical trials in this population and cannot be assumed that benefits observed in patients suffering from MI with obstructive coronary artery disease may successfully translate to this syndrome. Herein, we comment on the importance of the multimodality assessment to properly identify and treat the specific causes of MINOCA, in order to improve prognosis and the quality of life in these patients.

Clinical features, sex differences and outcomes of myocardial infarction with nonobstructive coronary arteries: a registry analysis

INTRODUCTION

Clinical characteristics and outcomes of patients diagnosed with myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) remain largely unknown. Furthermore, we do not yet understand if women with MINOCA have worse outcomes similar to what has historically been observed with MI. The aims of the current study were to evaluate the (1) incidence of MINOCA in patients presenting with MI, (2) compare in-hospital outcomes of MINOCA and obstructive atherosclerotic coronary artery disease MI (OACD-MI), and (3) comparison of in-hospital clinical outcomes of patients with MINOCA stratified by sex.

METHODS AND RESULTS

In this observational study, we combined data from two large university hospitals from Canada and Australia. Clinical characteristics and in-hospital outcomes of MINOCA and OACD-MI were analyzed by matching these patients in a 1:1 ratio after selecting patients with OACD-MI by systematic random sampling. Clinical characteristics associated with MINOCA were identified through multivariate logistic regression. Primary outcome of interest was net adverse cardiovascular events (NACE) defined as death, heart failure, stroke, and major bleeding. The incidence rate of MINOCA was 9.5%. Women, absence of traditional cardiac risk factors, and absence of ST-deviations on ECG were associated with diagnosis of MINOCA on angiography. NACE (P = 0.0001), death (P = 0.019), stroke (P = 0.002), and heart failure (P = 0.001) were significantly lower in patients with MINOCA. Subgroup analysis of women and men diagnosed with MINOCA revealed similar in-hospital outcomes.

CONCLUSION

The incidence of MINOCA was 9.5%. Compared to OACD-MI, patients with MINOCA have less cardiac risk factors. In-hospital outcomes of patients diagnosed with MINOCA were better than OACD-MI.

Guidelines for the management of myocardial infarction/injury with non-obstructive coronary arteries (MINOCA): a position paper from the Dutch ACS working group

Patients with myocardial infarction and non-obstructive coronary arteries (MINOCA), defined as angiographic stenosis <50%, represent a conundrum given the many potential underlying aetiologies. Possible causes of MINOCA can be subdivided into coronary, myocardial and non-cardiac disorders. MINOCA is found in up to 14% of patients presenting with an acute coronary syndrome. Clinical outcomes including mortality, and functional and psychosocial status, are comparable to those of patients with myocardial infarction and obstructive coronary arteries. However, many uncertainties remain regarding the definition, clinical features and management of these patients. This position paper of the Dutch ACS working group of the Netherlands Society of Cardiology aims to stress the importance of considering MINOCA as a dynamic working diagnosis and to guide the clinician in the management of patients with MINOCA by proposing a clinical diagnostic algorithm.

Myocardial Infarction with Non-Obstructive Coronary Arteries: Contemporary Diagnostic and Management Approaches

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is diagnosed in the absence of anatomically significant stenoses (<50% of lumen diameter) on coronary angiography and characterized by heterogeneity of etiologic factors. Recently, the mechanisms of MINOCA as well as the performance of diagnostic algorithms and therapeutic strategies have been extensively studied. The purpose of this review is to reflect the current concepts regarding the etiology and pathogenesis of MINOCA, diagnostic work-up methods and individualized treatment approaches. The article covers contemporary epidemiologic data, demographic and clinical patients’ characteristics and principal causes of MINOCA. We discuss aspects of disease definition and classification of related conditions involving troponin increase in the presence of normal coronary arteries. The importance of management strategy personalization for individual patients is stressed alongside stratification of risks of recurrent cardiovascular events. This review reflects key points from international consensus statements published by leading experts and suggests promising directions for future research.

Patients with acute myocardial infarction and non-obstructive coronary arteries: safety and prognostic relevance of invasive coronary provocative tests

Aims

Functional alterations of epicardial coronary arteries or coronary microcirculation represent a frequent cause of myocardial infarction and non-obstructive coronary arteries (MINOCA). We aimed at assessing the prognostic value of intracoronary provocative tests in patients presenting with MINOCA and in which other causes of MINOCA have been excluded.

Methods and results

We prospectively evaluated patients with a diagnosis of MINOCA, excluding patients with aetiologies other than suspected coronary vasomotor abnormalities. Immediately after coronary angiography, an invasive provocative test using acetylcholine or ergonovine was performed. The incidence of death from any cause, cardiac death, and recurrence of acute coronary syndrome (ACS) was assessed at follow-up. We also assessed angina status using Seattle Angina Questionnaires (SAQ). We enrolled 80 consecutive patients [mean age 63.0 ± 10.7 years, 40 (50%) male]. Provocative test was positive in 37 (46.2%) patients without any complication. Among patients with a positive test, epicardial spasm was detected in 24 (64.9%) patients and microvascular spasm in 13 (35.1%) patients. After a median follow-up of 36.0 (range 12.0-60.0) months, patients with a positive test had a significantly higher occurrence of death from any cause [12 (32.4%) vs. 2 (4.7%); P = 0.002], cardiac death [7 (18.9%) vs. 0 (0.0%); P = 0.005], and readmission for ACS [10 (27.0%) vs. 3 (7.0%); P = 0.015] as well as a worse angina status as assessed by SAQ [Seattle score: 88.0 (33.0-100.0) vs. 100.0 (44.0-100.0); P = 0.001] when compared with patients with a negative test.

Conclusions

We demonstrate that in patients presenting with MINOCA and suspected coronary vasomotor abnormalities, a positive provocative test for spasm is safe and identifies a high-risk subset of patients.

Clinical use of intracoronary imaging. Part 2: acute coronary syndromes, ambiguous coronary angiography findings, and guiding interventional decision-making: an expert consensus document of the European Association of Percutaneous Cardiovascular Interventions

This consensus document is the second of two reports summarizing the views of an expert panel organized by the European Association of Percutaneous Cardiovascular Interventions (EAPCI) on the clinical use of intracoronary imaging including intravascular ultrasound (IVUS), optical coherence tomography (OCT), and near infrared spectroscopy (NIRS)-IVUS. Beyond guidance of stent selection and optimization of deployment, invasive imaging facilitates angiographic interpretation and may guide treatment in acute coronary syndrome. Intravascular imaging can provide additional important diagnostic information when confronted with angiographically ambiguous lesions and allows assessment of plaque morphology enabling identification of vulnerability characteristics. This second document focuses on useful imaging features to identify culprit and vulnerable coronary plaque, which offers the interventional cardiologist guidance on when to adopt an intracoronary imaging-guided approach to the treatment of coronary artery disease and provides an appraisal of intravascular imaging-derived metrics to define the haemodynamic significance of coronary lesions.

ST-segment elevation and cardiac magnetic resonance imaging findings in myocardial infarction with non-obstructive coronary arteries

PURPOSE

Patients with myocardial infarction and non-obstructive coronary arteries (MINOCA) may present with or without ST-elevation (STE) on the electrocardiogram (ECG). Previous studies have shown that STE was associated with higher risk of early mortality and long-term major adverse coronary events, and that cardiac magnetic resonance imaging (CMR) can help to determine whether the cause of a MINOCA presentation is ischemic or non-ischemic. We set out to determine the relationship between STE and CMR findings in patients presenting with MINOCA.

DESIGN

Patients who underwent CMR based on a provisional diagnosis of MINOCA were pooled from three prospective cohort studies: the multicenter Stockholm Myocardial Infarction with Normal Coronaries, a prospective University of Adelaide study, and a prospective NYU School of Medicine diagnostic imaging study. STE was defined as ≥1 mm in ≥2 contiguous leads.

RESULTS

Among 292 patients, average age was 57.0 years (±11.9), and 68% were female. Fifty-seven had STE, 231 had no STE and four had left bundle branch block. There was no difference between patients with vs. without STE in the likelihood of the CMR findings of infarction (21% vs. 18%), myocarditis (10% vs. 14%), left ventricular wall motion pattern consistent with takotsubo syndrome on CMR (16% vs. 14%).

CONCLUSION

STE on the presenting ECG was not associated with CMR findings in patients with a provisional diagnosis of MINOCA. Based on these findings, increased risk among MINOCA patients with STE does not appear to be related to variation in these CMR findings.

Morbidity and cause-specific mortality in first-time myocardial infarction with nonobstructive coronary arteries

BACKGROUND

Myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) is receiving increasing interest as a prognostically adverse entity distinct from myocardial infarction with significant coronary artery disease (MI-CAD). However, data are still limited regarding long-term cardiovascular morbidity and cause-specific mortality in MINOCA.

METHODS

This is a registry-based cohort study using data from patients admitted to Swedish coronary care units. We investigated various nonfatal outcomes (recurrent MI, hospitalization for heart failure or stroke) and fatal outcomes (cardiovascular, respiratory or cancer-related mortality) in 4069 patients without apparent acute cardiovascular disease, used as non-MI controls, 7266 patients with first-time MINOCA and 69 267 patients with first-time MI-CAD.

RESULTS

Almost all event rates (median follow-up 3.8 years) increased in a stepwise fashion across the three cohorts [rates of major adverse events (MAE; composite of all-cause mortality, recurrent MI, hospitalization for heart failure or stroke): n = 268 (6.6%), n = 1563 (21.5%), n = 17 777 (25.7%), respectively]. Compared to non-MI controls, MINOCA patients had an adjusted hazard ratio (HR) of 2.12 (95% confidence interval 1.84-2.43) regarding MAE. MINOCA patients had a substantial risk of cardiovascular mortality and the highest numerical risks of respiratory and cancer-related mortality. Male sex, previous heart failure and chronic obstructive pulmonary disease had a stronger prognostic impact in MINOCA than in MI-CAD. Female MINOCA patients with atrial fibrillation were at particular risk.

CONCLUSIONS

Patients with first-time MINOCA have a considerable risk of adverse events. This stresses the need for a comprehensive search of the cause of MINOCA, thorough treatment of underlying disease triggers and close follow-up.

Characteristics of patients with myocardial infarction with nonobstructive coronary arteries (MINOCA) from the ARIAM-SEMICYUC registry: development of a score for predicting MINOCA

Background

Acute myocardial infarction (AMI) with no evidence of relevant stenosis of the coronary artery, known as myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA), has a prevalence of up to 14%. The various causes of MINOCA lead to damage of the myocardium, and there are marked differences in diagnoses, prognoses, and treatments. Although the number of patients affected is considerable owing to the high prevalence of acute coronary syndrome (ACS), the causes of MINOCA have received little attention with the result that some patients may not receive appropriate treatment. Awareness of this disease among clinicians has started only to improve since the beginning of the current century. The aim of this study was to develop a score that enables patients with MINOCA to be distinguished from patients with MI with coronary artery disease (MI-CAD) and thus to facilitate appropriate diagnosis and therapy.

Patients and methods

A multicenter observational cohort study was designed. All patients aged ≥18 years from the ARIAM-SEMICYUC (Analysis of Delay in AMI-Spanish Society of Intensive Care Medicine and Coronary Unit) registry, diagnosed with AMI, and admitted to critical care units or coronary care units (CCUs) were included. Patients were classified into two groups: MINOCA, comprising patients with no significant lesions on angiography, and MI-CAD, comprising patients with lesions of the coronary artery tree.

Results

A score based on standard variables to assess the probability of MINOCA on admission was designed, showing a maximum value corresponding to a 40% probability of MINOCA. The discriminative power of the model was 0.756 (P-value for the Hosmer-Lemeshow test was >0.05). At 30-day follow-up, the mortality rate was higher for MI-CAD patients.

Conclusion

Patients with MINOCA constitute a population that differs from other patients with AMI. Their differential characteristics require a certain diagnostic effort to align therapy with the disease causing the ischemic event. This score could prove useful in establishing additional diagnostic procedures.

Predictors of poor clinical outcomes in patients with acute myocardial infarction and non-obstructed coronary arteries (MINOCA)

OBJECTIVE

To assess the characteristics and prognosis of patients with myocardial infarction and non-obstructed coronary arteries (MINOCA).

METHODS

MINOCA was defined as acute myocardial infarction (AMI) with angiographic coronary stenosis <50%.Cardiomyopathies and myocarditis were - a priori - excluded from the study. Stenoses <30% were considered normal coronary arteries (NCA); stenoses ≥30% but <50% were considered mild coronary artery disease (MCAD). Patients were subdivided in 3 groups: I) NCA (0 vessels; stenosis <30%); II) 1-2 vessels showing MCAD and III) MCAD in 3 vessels or the left main stem (LMS).

RESULTS

From January 2006 to December 2014, 7935 consecutive AMI patients were entered into our institutional database;150 (2%) were diagnosed as having MINOCA. At a median follow-up of 7.1 years the composite end-point (cardiovascular death, AMI or acute coronary syndrome, heart failure, stroke) occurred in 23 patients (17.4%). Survival analysis showed no differences between NCA versus MCAD (p = 0.781). When assessed by distribution of CAD, group III had a lower event-free survival compared to group I and group II, respectively 54 ± 14%, 83 ± 4% and 90 ± 5% (p = 0.001). In a multivariate model, only 3 vessel disease or LMS involvement (HR = 23.5, 95% CI 2.59-173.49, P = 0.001) and high C-reactive protein at hospital admission (HR = 1.47, 95% CI 1.06-2.07, P = 0.005) were significant predictors of the study composite endpoint.

CONCLUSIONS

In patients with MINOCA, the presence of NCA or 1-2 vessel MCAD was associated with better long-term clinical outcomes compared with patients with MCAD affecting 3 vessels or the LMS. Increased CRP concentrations on hospital admission were also a marker of worse clinical outcome during follow-up.

Outcome after myocardial infarction without obstructive coronary artery disease

OBJECTIVE

The medium-term outcome and cause of death in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) is not well characterised. The aim of this study was to compare mortality and rates of recurrent events in post myocardial infarction (MI) patients with obstructive coronary artery disease (CAD) and in patients with MINOCA compared with an age and sex-matched cohort without cardiovascular disease (CVD).

METHODS

We performed a national cohort study of consecutive patients undergoing coronary angiography for MI during 2 years between 2013 and 2015 from the All New Zealand Acute Coronary Syndrome-Quality Improvement (ANZACS QI) registry. MI patient registry data were linked anonymously to national hospitalisation and mortality records. Age and sex matched patients without known CVD formed the comparison group.

RESULTS

Of the 8305 patients with MI, 897 (10.8%) were classified as MINOCA. Compared with those without known CVD, the adjusted HRs for the primary outcome (all-cause death or recurrent non-fatal MI) were 7.81 (95% CI 6.64 to 9.19, p<0.0001) in those with obstructive CAD and 4.64 (95% CI 3.54 to 6.10, p<0.0001) in those with MINOCA. Kaplan-Meier all-cause mortality at 2 years was 7.9% for those with obstructive CAD, with nearly half being CVD deaths (3.6% CVD deaths and 4.5% non-CVD deaths, respectively). In contrast, MINOCA all-cause mortality was 4.9% with non-CVD death (4.5%) predominating.

CONCLUSIONS

MINOCA is common and has an adverse outcome rate approximately half than that of those with obstructive CAD. The predominant contributor to mortality is non-CVD death. The rate of events in MINOCA is significantly greater than the population without CVD.

Editor's Choice- Pathophysiology, diagnosis and management of MINOCA: an update

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a syndrome with different causes, characterised by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography. Its prevalence ranges between 5% and 25% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, cardiac enzymes, echocardiography, coronary angiography and left ventricular angiography represent the first level diagnostic investigations to identify the causes of MINOCA. Regional wall motion abnormalities at left ventricular angiography limited to a single epicardial coronary artery territory identify an 'epicardial pattern'whereas regional wall motion abnormalities extended beyond a single epicardial coronary artery territory identify a 'microvascular pattern'. The most common causes of MINOCA are represented by coronary plaque disease, coronary dissection, coronary artery spasm, coronary microvascular spasm, Takotsubo cardiomyopathy, myocarditis, coronary thromboembolism, other forms of type 2 myocardial infarction and MINOCA of uncertain aetiology. This review aims at summarising the diagnosis and management of MINOCA, according to the underlying physiopathology.

Patients with non-obstructive coronary artery disease admitted with acute myocardial infarction carry a better outcome compared to those with obstructive coronary artery disease

Background

The characterization of patients who have acute myocardial infarction (AMI) and insignificant coronary stenosis is unclear.

Aim

The present study aimed to investigate the clinical profile, in-hospital and 3-month outcome of AMI patients with insignificant coronary stenosis in comparison with those with significant disease.

Methods

This prospective observational study included 200 consecutive patients admitted with AMI. Group I (100 patients) included patients with insignificant CAD (all lesions <50% stenosis). Group II (100 patients) included patients with one or more lesions >70% stenosis. Patients with previous CABG were excluded. Patients with significant CAD had successful total revascularization.

Results

Patients with insignificant CAD were significantly younger (61 vs. 67 years, p < 0.001), more likely to be females (41% vs. 23%, p = 0.006), less likely to smoke (p = 0.006), less likely to have diabetes mellitus (p < 0.001), and less likely to have history of CAD (p = 0.042) or prior PCI (p = 0.037). They were also less likely to have typical anginal pain at presentation (61% vs 91%, p < 0.001), less likely to have heart failure at presentation (9% vs 30%, p < 0.001), less likely to have ischemic ST-segment changes on presentation (10% vs 46%, p < 0.001), lower peak troponin (p < 0.001) and CK-MB levels (p < 0.001), with lower LDL-C (p = 0.006), and higher HDL-C level (p = 0.020). They were less likely to be treated with b-blockers (p = 0.002), ACEI/ARBS (p = 0.007), and higher rates of calcium channel blocker therapy (p < 0.001). They had lower prevalence of major adverse clinical events at follow-up (readmission for ACS (p = 0.009), need for revascularization (p = 0.035), recurrent chest pain (p = 0.009), and cardiogenic shock (p = 0.029).

Conclusion

Patients with AMI and insignificant CAD have different clinical profile and outcome compared to those with significant disease.

Sex Differences in the Management and 5-Year Outcome of Young Patients (<55 Years) with Acute Coronary Syndromes

BACKGROUND

Young women are usually protected against coronary artery disease due to hormonal and risk-factor profile. Previous studies have suggested poorer outcome in women hospitalized with acute coronary syndrome as compared with men. However, when adjusted for age and other risk factors, this difference does not remain significant. We compared the risk profile and outcome between young (≤55 years) women and men admitted with acute coronary syndrome.

METHODS

We analyzed clinical characteristics, management strategies, and outcomes of men and women ≤55 years of age enrolled in the biennial Acute Coronary Syndrome Israeli Surveys between 2000 and 2013.

RESULTS

Among 11,536 patients enrolled, 3949 (34%) were ≤55 years old (407 women, 3542 men). Women were slightly older (48.9 ± 5.7 vs 48.3 ± 5.5, P = .007) and suffered more from diabetes (34% vs 24%) and hypertension (47% vs 37%, P <.001 for both). Rates of prior myocardial infarction were high in both sexes (18% vs 21%). Women presented less often with ST-elevation myocardial infarction (50% vs 57%, P = .007) and with typical chest pain (73% vs 80%, P = .004), and had higher rates of Global Registry of Acute Coronary Events (GRACE) score ≥140 (19% vs 12%, P = .007). After adjustment for GRACE score, diabetes, and enrollment year, women had a lower likelihood to undergo coronary angiography during hospitalization (odds ratio 0.6, P = .007). Female sex was independently associated with higher risk of in-hospital mortality (hazard ratio [HR] 4.1; 95% confidence interval [CI], 1.15-14.0), 30-day major adverse cardiac and cerebral events (HR 2.1; 95% CI, 1.31-3.36), and 5-year mortality (HR 1.96; 95% CI, 1.3-2.8).

CONCLUSIONS

Young women admitted with acute coronary syndrome are a unique high-risk group that presents a diagnostic challenge for clinicians. Women receive less invasive therapy during hospitalization and have worse in-hospital and long-term outcomes.