Outcome after myocardial infarction without obstructive coronary artery disease

Maturation of Human iPSC-Derived Cardiac Microfiber with Electrical Stimulation Device

Here an electrical stimulation system is described for maturing microfiber-shaped cardiac tissue (cardiac microfibers, CMFs). The system enables stable culturing of CMFs with electrical stimulation by placing the tissue between electrodes. The electrical stimulation device provides an electric field covering whole CMFs within the stimulation area and can control the beating of the cardiac microfibers. In addition, CMFs under electrical stimulation with different frequencies are examined to evaluate the maturation levels by their sarcomere lengths, electrophysiological characteristics, and gene expression. Sarcomere elongation (14% increase compared to control) is observed at day 10, and a significant upregulation of electrodynamic properties such as gap junction protein alpha 1 (GJA1) and potassium inwardly rectifying channel subfamily J member 2 (KCNJ2) (maximum fourfold increase compared to control) is observed at day 30. These results suggest that electrically stimulated cultures can accelerate the maturation of microfiber-shaped cardiac tissues compared to those without electrical stimulation. This model will contribute to the pathological research of unexplained cardiac diseases and pharmacologic testing by stably constructing matured CMFs.

Sex differences in outcomes after acute coronary syndrome vary with age: a New Zealand national study

AIMS

This study investigated age-specific sex differences in short- and long-term clinical outcomes following hospitalization for a first-time acute coronary syndrome (ACS) in New Zealand (NZ).

METHODS AND RESULTS

Using linked national health datasets, people admitted to hospital for a first-time ACS between January 2010 and December 2016 were included. Analyses were stratified by sex and 10-year age groups. Logistic and Cox regression were used to assess in-hospital death and from discharge the primary outcome of time to first cardiovascular (CV) readmission or death and other secondary outcomes at 30 days and 2 years. Among 63 245 people (mean age 69 years, 40% women), women were older than men at the time of the ACS admission (mean age 73 vs. 66 years), with a higher comorbidity burden. Overall compared with men, women experienced higher rates of unadjusted in-hospital death (10% vs. 7%), 30-day (16% vs. 12%) and 2-year (44% vs. 34%) death, or CV readmission (all P < 0.001). Age group-specific analyses showed sex differences in outcomes varied with age, with younger women (<65 years) at higher risk than men and older women (≥85 years) at lower risk than men: unadjusted hazard ratio of 2-year death or CV readmission for women aged 18-44 years = 1.51 [95% confidence interval (CI) 1.21-1.84] and aged ≥85 years = 0.88 (95% CI 0.83-0.93). The increased risk for younger women was no longer significant after multivariable adjustment whereas the increased risk for older men remained.

CONCLUSION

Men and women admitted with first-time ACS have differing age and comorbidity profiles, resulting in contrasting age-specific sex differences in the risk of adverse outcomes between the youngest and oldest age groups.

Clinical outcomes of myocardial infarction with non-obstructive coronary arteries presenting with diabetic ketoacidosis: a propensity score-matched analysis

INTRODUCTION AND OBJECTIVE

There is a paucity of data on patients with myocardial infarction with nonobstructive coronary arteries (MINOCA) and a decompensated diabetic state, diabetic ketoacidosis (DKA). Therefore, we aimed to investigate the outcomes of patients with MINOCA presenting with or without DKA.

METHODS

We conducted this retrospective propensity score-matched analysis from January 1, 2015, to December 4, 2022. The patients with a principal admission diagnosis of ST-Elevation MI (STEMI) and discharge labeled as MINOCA (ICD-10-CM code 121.9) with DKA were analyzed. We performed a comparative analysis for MINOCA with and without DKA before and after propensity score matching for primary and secondary endpoints.

RESULTS

Three thousand five hundred sixty-three patients were analyzed, and 1150 (32.27%) presented with DKA, while 2413 (67.72%) presented as non-DKA. The DKA cohort had over two-fold mortality (5.56% vs. 1.19%; p = 0.024), reinfarction (5.82% vs. 1.45%; p = 0.021), stroke (4.43% vs. 1.36%; p = 0.035), heart failure (6.89% vs. 2.11%; p = 0.033), and cardiogenic shock (6.43% vs. 1.78%; p = 0.025) in a propensity score-matched analysis. There was an increased graded risk of MINOCA with DM (RR (95% CI): 0.50 (0.36-0.86; p = 0.023), DKA (RR (95% CI): 0.46 (0.24-0.67; p = 0.001), and other cardiovascular (CV) risk factors.

CONCLUSION

DKA complicates a portion of MINOCA and is associated with increased mortality and major adverse cardiovascular events (MACE).

Long term all-cause mortality after myocardial infarction with non-obstructed vs obstructed coronary artery disease: a meta-analysis of adjusted data

BACKGROUND

The difference in the long-term outcomes of myocardial infarction in patients with non-obstructed coronary arteries (MINOCA) and patients with myocardial infarction with obstructed coronary artery disease (MI-CAD) is not clear. The current study aimed to pool adjusted data to compare long-term outcomes of MINOCA vs MI-CAD.

METHODS

Electronic literature search of PubMed, Embase, CENTRAL, and Google Scholar databases was done for publications up to 18th June 2023. Only studies reporting multivariable-adjusted data with > 1 year of follow-up were included.

RESULTS

Sixteen studies met the inclusion criteria. Our meta-analysis revealed no statistically significant difference in the risk of all-cause mortality between MINOCA and MI-CAD patients (HR: 0.90 95% CI 0.68, 1.19 I2 = 94% p = 0.48). Analysis of the limited data showed a reduced combined risk of all-cause mortality and MI (HR: 0.54 95% CI 0.39, 0.76 I2 = 72% p = 0.003) and major adverse cardiac events (MACE) (HR: 0.66 95% CI 0.51, 0.84 I2 = 51% p = 0.0009) in patients with MINOCA vs MI-CAD, and no difference in the risk of cardiovascular mortality (HR: 0.81 95% CI 0.54, 1.22 I2 = 0% p = 0.31) and readmission between the two groups (HR: 0.85 95% CI 0.61, 1.19 I2 = 90% p = 0.35).

CONCLUSION

A pooled analysis of adjusted outcomes from the available studies indicated that MINOCA and MI-CAD patients have similar long-term all-cause mortality risk. Our conclusions on the risk of cardiovascular mortality, MACE and readmission rates need to be taken with caution due to a lack of adequate studies. Further research is needed to strengthen the evidence on this important subject.

Outcomes and Medical Therapy in Myocardial Infarction With Nonobstructive Coronary Arteries: A Systematic Review and Meta-Analysis

Myocardial infarction with nonobstructive coronary arteries (MINOCAs) is a disease that has been poorly characterized with unclear clinical and therapeutic outcomes. The association of medical therapy with cardiovascular outcomes in patients with MINOCA has been inadequately assessed. The purpose of this meta-analysis is to evaluate the association of MINOCA at risk of adverse cardiovascular outcomes as compared with myocardial infarction with coronary artery disease (MICAD) and the efficacy of medical therapy in reducing the risk of adverse outcomes. A literature search was conducted for studies reporting on the association of MINOCA at risk of adverse outcomes as compared with MICAD. A literature search was also conducted for studies reporting on the association of medical therapy at risk of adverse outcomes in patients with MINOCA. A total of 29 studies with 893,134 participants met inclusion criteria comparing MINOCA to MICAD. Patients with MINOCA had a significantly lower risk of adverse outcomes as compared with MICAD. Nine studies with 27,731 MINOCA patients met inclusion criteria for evaluating the utility of medical therapy. Medical therapy did not significantly reduce risk of MACE; however, there was a trend toward lower risk in patients treated with β blockers. In conclusion, our results suggest that MINOCA is associated with a lower risk of in-hospital and long-term adverse outcomes compared with MICAD. Standard medical therapy is not associated with a lower risk of adverse cardiovascular outcomes in patients with MINOCA. Additional high-quality studies are required to evaluate the utility of specific medication classes for the treatment of specific etiologies of MINOCA.

Medium-Term Prognostic Implications of Cardiac Magnetic Resonance Imaging in Patients With Myocardial Infarction With Nonobstructive Coronary Arteries (MINOCA): A Systematic Review and Meta-Analysis

BACKGROUND

This study aimed to evaluate the medium-term prognostic implications of cardiac magnetic resonance (CMR) imaging in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA).

METHODS

A systematic literature search of Embase, PubMed, and The Cochrane Library was performed. Eligible studies reported outcomes of CMR-assessed MINOCA with a mean follow-up period of >6 months. The primary endpoint was all-cause death. Secondary endpoints included cardiac death, reinfarction, and cardiovascular rehospitalisation. The pooled effect sizes with 95% confidence interval (CIs) were estimated using a random effect model.

RESULTS

A total of 3,050 patients from twenty-one studies were included in the meta-analysis. The prevalence of myocarditis, "true" myocardial infarction, Takotsubo cardiomyopathy, and normal CMR imaging was 36%, 25%, 14%, and 19%, respectively. Pooled data showed that the annualised event rates for all-cause mortality, cardiac mortality, reinfarction, and cardiovascular rehospitalisation were 1.01% (95% CI 0.59%-1.51%), 0.06% (95% CI 0.00%-0.39%), 0.68% (95% CI 0.18%-1.38%), and 5.67% (95% CI 3.11%-8.85%), respectively. Compared with patients with a diagnosis of myocarditis on CMR, patients with Takotsubo cardiomyopathy (RR 7.11; 95% CI 3.04-16.66) and "true" myocardial infarction (RR 3.82; 95% CI 1.65-8.86) were associated with a significantly higher risk of all-cause mortality, whereas a similar risk of all-cause mortality was observed in patients with normal imaging (RR 1.01; 95% CI 0.28-3.59). No association was found between CMR diagnoses and the risk of secondary endpoints in MINOCA.

CONCLUSIONS

In patients with MINOCA assessed by CMR, the overall absolute incidence rates of mortality and reinfarction were low. However, certain imaging diagnoses were associated with a higher risk of all-cause mortality, with most deaths attributed to non-cardiac causes. Additionally, these patients experienced a high burden of cardiovascular rehospitalisation.

REGISTRATION

PROSPERO (CRD42022323615).

Characteristics of patients with recurrent acute myocardial infarction after MINOCA

BACKGROUND

Myocardial infarction (MI) with non-obstructed coronary arteries (MINOCA) is an increasingly recognized condition with challenging management. Some MINOCA patients ultimately experience recurrent acute MI (re-AMI) during follow-up; however, clinical and angiographic factors predisposing to re-AMI are still poorly defined.

METHODS

In this retrospective multicenter cohort study we enrolled consecutive patients fulfilling diagnostic criteria of MINOCA according to the IV universal definition of myocardial infarction; characteristics of patients experiencing re-AMI during the follow-up were compared to a group of MINOCA patients without re-AMI.

RESULTS

54 patients (mean age 66 ± 13) experienced a subsequent re-AMI after MINOCA and follow-up was available in 44 (81%). Compared to MINOCA patients without re-AMI (n = 695), on first invasive coronary angiography (ICA) MINOCA patients with re-AMI showed less frequent angiographically normal coronaries (37 versus 53%, p = 0.032) and had a higher prevalence of atherosclerosis involving 3 vessels or left main stem (17% versus 8%, p = 0.049). Twenty-four patients (44%) with re-AMI underwent a new ICA: 25% had normal coronary arteries, 12.5% had mild luminal irregularities (<30%), 20.8% had moderate coronary atherosclerosis (30-49%), and 41.7% showed obstructive coronary atherosclerosis (≥50% stenosis). Among patients undergoing new ICA, atherosclerosis progression was observed in 11 (45.8%), 37.5% received revascularization, only 4.5% had low-density lipoprotein cholesterol (LDL_C) under 55 mg/dL and 33% experienced a new cardiovascular disease (CVD) event (death, AMI, heart failure, stroke) at subsequent follow-up.

CONCLUSIONS

In the present study, only a minority of MINOCA patients with re-AMI underwent a repeated ICA, nearly one out of two showed atherosclerosis progression, often requiring revascularization. Recommended LDL-C levels were achieved only in a minority of the cases, indicating a possible underestimation of CVD risk in this population.

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.

Comparison of Long-Term Outcomes of Patients With Myocardia Infarction (MI) With Non-obstructive Coronary Arteries and MI With Obstructive Coronary Arteries: A Systematic Review and Meta-Analysis

The aim of this study was to compare long-term outcomes in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA) and patients with myocardial infarction with obstructive coronary arteries (MIOCA). This meta-analysis was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The literature search was conducted in online databases including PubMed and Web of Science from 2010 onwards. Primary outcomes assessed in this meta-analysis included major adverse cardiovascular events (MACE) and all-cause mortality. Secondary outcomes included cardiovascular mortality and myocardial infarction. A total of 16 studies were included in the meta-analysis. Pooled analysis showed that the risk of MACE was higher in MIOCA patients (risk ratio (RR): 1.47, 95%CI: 1.43-1.52, p-value: 0.001) compared to MINOCA patients. Additionally, the risk of all-cause mortality was also significantly higher in MIOCA patients compared to MINOCA (RR: 1.33, 95%CI: 1.14-1.56, p-value: 0.001). Our findings also indicate that patients with MIOCA are at a significantly higher risk of recurrent myocardial infarction and cardiovascular-related mortality compared to patients with MINOCA. Overall, the insights gained from this meta-analysis have significant clinical implications, guiding decision-making in the management of patients with MINOCA.

MINOCA and INOCA: Role in Heart Failure

PURPOSE OF REVIEW

Infarction (MINOCA) and ischaemia (INOCA) with non-obstructive coronary disease are recent non-conventional presentations of coronary syndromes that are increasingly recognised in the clinical arena, particularly with the availability of new cardiovascular imaging techniques. Both are related to heart failure (HF). MINOCA is not associated with benign outcomes, and HF is among the most prevalent events. Regarding INOCA, microvascular dysfunction has also been found to associate with HF, particularly with preserved ejection fraction (HFpEF).

RECENT FINDINGS

Regardless of the several aetiologies underlying HF in MINOCA, it is likely related to LV dysfunction, where secondary prevention is not yet clearly established. Regarding INOCA, coronary microvascular ischaemia has been associated to endothelial dysfunction leading ultimately to diastolic dysfunction and HFpEF. MINOCA and INOCA are clearly related to HF. In both, there is a lack of studies on the identification of the risk factors for HF, diagnostic workup and, importantly, the appropriate primary and secondary prevention strategies.

Myocardial infarction with non-obstructive coronary arteries: Etiology, diagnosis, treatment and prognosis

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is responsible for 10% of myocardial infarctions. Previously, patients were thought to have good prognosis, but evidence-based management and treatment strategies were scarce. Today, researchers and physicians recognize MINOCA as a condition with non-trivial mortality and morbidity. Therapeutic strategies are highly dependent on the underlying disease mechanism in each patient. However, to reach a diagnosis of MINOCA, a multimodal approach is required and, even with an optimal work-up, the cause remains unknown in 8-25% of patients. Research has been growing and position papers from the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology have been published, and MINOCA has been included in the more recent ESC guidelines on myocardial infarction. Nonetheless, some clinicians still assume that the absence of coronary obstruction excludes the possibility of acute myocardial infarction. Therefore, in the present paper, we aim to compile and present the available data on the etiology, diagnosis, treatment, and prognosis of MINOCA.

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.

Sex differences in patients with acute coronary syndromes and non-obstructive coronary arteries: Presentation and outcome

BACKGROUND

A substantial number of patients present with a suspected ACS and non-obstructive coronary arteries; sex differences in these patients are not well understood. This study aims to evaluate the impact of sex on clinical presentation and outcome in patients with suspected acute coronary syndrome (ACS) and non-obstructive coronary arteries with a final diagnosis confirmed by cardiovascular magnetic resonance imaging (CMR).

METHODS

Consecutive patients with ACS and non-obstructive coronary arteries (n = 719) with an unclear cause from a single tertiary centre who were referred for CMR were included. The primary endpoint was all-cause mortality.

RESULTS

CMR was performed at a median time of 30 days after presentation and identified a diagnosis in 74% of patients. All-cause mortality was 9.5% over a median follow up of 4.9 years, with no significant difference between sexes (8.8% versus 10.1%; p = 0.456). Men were more likely to have non-ischaemic aetiology on CMR than women (55% v 41%, p < 0.001), but were equally likely to have an ischaemic cause (25% v 27%, p = 0.462). Age group (HR 1.58, p < 0.001) and LV ejection fraction (HR 0.98, p = 0.023) were independent predictors of mortality.

CONCLUSIONS

There is no difference in all-cause mortality between sexes in patients presenting with suspected ACS and non-obstructive coronary arteries.

Myocardial Infarction with Nonobstructive Coronary Arteries

Myocardial infarction with nonobstructive coronary arteries (MINOCA) is an important subtype of myocardial infarction (MI) that occurs in approximately 6-8% of patients with spontaneous MI who are referred for coronary angiography. MINOCA disproportionately affects women, but men are also affected. Pathogenesis is more variable than in MI with obstructive coronary artery disease (MI-CAD). Dominant mechanisms include atherosclerosis, thrombosis, and coronary artery spasm. Management of MINOCA varies based on the underlying mechanism of infarction. Therefore, systematic approaches to diagnosis are recommended. The combination of invasive coronary angiography, multivessel intracoronary imaging, provocative testing for coronary spasm, and cardiac magnetic resonance imaging provides the greatest diagnostic yield. Current clinical practice guidelines for the secondary prevention of MI are based largely on data from patients with MI-CAD. Thus, optimal medications after MINOCA are uncertain. Clinical trials focused on the treatment of patients with MINOCA are urgently needed to define optimal care.

Association of stress hyperglycemia ratio and poor long-term prognosis in patients with myocardial infarction with non-obstructive coronary arteries

BACKGROUND

Stress hyperglycemia ratio (SHR) is a novel biomarker of true acute hyperglycemia condition and is associated with a worse prognosis in patients with myocardial infarction (MI). However, the effects of SHR in the setting of MI with non-obstructive coronary arteries (MINOCA) have not been investigated. This study aimed to explore the association between SHR and long-term clinical outcomes among MINOCA patients.

METHODS

A total of 410 MINOCA patients were included in the final analysis of this study. The patients were divided into three groups based on the SHR tertiles: [SHR1 group (SHR ≤ 0.73), (n = 143); SHR2 group (SHR 0.73-0.84), n = 131; and SHR3 group (SHR ≥ 0.84), n = 136]. Follow-up for major adverse cardiovascular events (MACE) was conducted on all patients. Cox regression and Kaplan-Meier curve analysis were used to evaluate the relationship between SHR and MACE. The receiver operating curve (ROC) analysis was applied to obtain the optimal cut-off value of SHR for predicting clinical MACE.

RESULTS

A total of 92 patients developed MACE during the mean 34 months of follow-up. A significant increase in MACE was observed in the SHR3 group compared to the SHR1 and SHR2 groups (35.3% vs. 15.4% and 16.8%, respectively; P < 0.001). The Kaplan-Meier curves demonstrate that SHR3 patients had the highest MACE risk compared to SHR1 and SHR2 patients (log-rank P < 0.001). In addition, when both SHR tertiles and diabetes status were considered, those with SHR3 and diabetes had the highest hazard of MACE (log-rank P < 0.001). Multivariate Cox regression analysis showed that the SHR3 is associated with a 2.465-fold increase in the risk of MACE (adjusted HR, 2.465; 95% CI 1.461-4.159, P = 0.001). The ROC curve analysis showed that the optimal SHR cut-off value for predicting clinical MACE among MINOCA was 0.86.

CONCLUSION

Our data indicates, for the first time, that SHR is independently associated with poor long-term prognosis in patients suffering from MINOCA. The optimal SHR cut-off value for predicting clinical MACE among MINOCA patients was 0.86. These findings suggest that SHR may play a potential role in the cardiovascular risk stratification of the MINOCA population.

Myocardial Infarction With Non-obstructive Coronary Arteries: Risk Factors and Associated Comorbidities

Myocardial infarction with non-obstructive coronary arteries (MINOCA), despite a lower burden of coronary atherosclerosis, has a non-negligible prognostic impact. The label of MINOCA includes an array of different aetiologies and pathologic conditions, thus the identification of the underlying disease is crucial to patient management. Myocardial infarction with obstructive coronary artery disease and MINOCA share only some risk factors and comorbid conditions. While traditional cardiovascular risk factors have a lower prevalence in MINOCA patients, atypical ones—e.g., anxiety, depression, and autoimmune diseases—are much more frequent in this population. Other conditions—e.g., pregnancy, cancer, and anti-cancer therapy—can predispose to or even induce MINOCA through various mechanisms. The evidence of such risk factors for MINOCA is still scarce and contradicting, as no randomised controlled trials exist in this field. In our work, we performed a review of registries, clinical studies, and case reports of MINOCA, in order to summarise the available data and analyse its possibile pathogenic mechanisms.

Distribution Characteristics of ST-Segment Elevation Myocardial Infarction and Non-ST-Segment Elevation Myocardial Infarction Culprit Lesion in Acute Myocardial Infarction Patients Based on Coronary Angiography Diagnosis

This research was aimed at exploring the application value of coronary angiography (CAG) based on a convolutional neural network algorithm in analyzing the distribution characteristics of ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) culprit lesions in acute myocardial infarction (AMI) patients. Methods. Patients with AMI treated in hospital from June 2019 to December 2020 were selected as subjects. According to the results of an echocardiogram, the patients were divided into the STEMI group (44 cases) and the NSTEMI group (36 cases). All patients received CAG. All images were denoised and edge detected by a convolutional neural network algorithm. Then, the number of diseased vessels, the location of diseased vessels, and the degree of stenosis of diseased vessels in the two groups were compared and analyzed. Results. The number of patients with complete occlusion (3 cases vs. 12 cases) and collateral circulation (5 cases vs. 20 cases) in the NSTEMI group was significantly higher than that in the STEMI group, and the difference was statistically significant, P < 0.05. There was a statistically significant difference in the number of lesions between the distal LAD (1 case vs. 10 cases) and the distal LCX (4 cases vs. 11 cases), P < 0.05. There was a statistically significant difference in the number of patients with one lesion branch (1 vs. 18) and three lesion branches (25 vs. 12) between the two groups, P < 0.05. The image quality after the convolution neural network algorithm is significantly improved, and the lesion is more prominent. Conclusion. The convolutional neural network algorithm has good performance in DSA image processing of AMI patients. STEMI and NSTEMI as the starting point of AMI disease analysis to determine the treatment plan have high clinical application value. This work provided reference and basis for the application of the convolutional neural network algorithm and CAG in the analysis of the distribution characteristics of STEMI and NSTEMI culprit lesions in AMI patients.

Survival in Patients With Suspected Myocardial Infarction With Nonobstructive Coronary Arteries: A Comprehensive Systematic Review and Meta-Analysis From the MINOCA Global Collaboration

BACKGROUND

Suspected myocardial infarction (MI) with nonobstructive coronary arteries (MINOCA) occurs in ≈5% to 10% of patients with MI referred for coronary angiography. The prognosis of these patients may differ to those with MI and obstructive coronary artery disease (MI-CAD) and those without a MI (patients without known history of MI [No-MI]). The primary objective of this study is to evaluate the 12-month all-cause mortality of patients with MINOCA.

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the terms "MI," "nonobstructive," "angiography," and "prognosis" were searched in PubMed and Embase databases from inception to December 2018, including original, English language MINOCA studies with >100 consecutive patients. Publications with a heterogeneous cohort, unreported coronary stenosis, or exclusively focusing on MINOCA-mimicking conditions, were excluded. Unpublished data were obtained from the MINOCA Global Collaboration. Data were pooled and analyzed using Paule-Mandel, Hartung, Knapp, Sidik & Jonkman, or restricted maximum-likelihood random-effects meta-analysis methodology. Heterogeneity was assessed using Cochran's Q and I² statistics. The primary outcome was 12-month all-cause mortality in patients with MINOCA, with secondary comparisons to MI-CAD and No-MI.

RESULTS

The 23 eligible studies yielded 55 369 suspected MINOCA, 485 382 MI-CAD, and 33 074 No-MI. Pooled meta-analysis of 14 MINOCA studies accounting for 30 733 patients revealed an unadjusted 12-month all-cause mortality rate of 3.4% (95% CI, 2.6%-4.2%) and reinfarction (n=27 605; 10 studies) in 2.6% (95% CI, 1.7%-3.5%). MINOCA had a lower 12-month all-cause mortality than those with MI-CAD (3.3% [95% CI, 2.5%-4.1%] versus 5.6% [95% CI, 4.1%-7.0%]; odds ratio, 0.60 [95% CI, 0.52-0.70], P<0.001). In contrast, there was a statistically nonsignificant trend towards increased 12-month all-cause mortality in patients with MINOCA (2.6% [95% CI, 0%-5.9%]) compared with No-MI (0.7% [95% CI, 0.1%-1.3%]; odds ratio, 3.71 [95% CI, 0.58-23.61], P=0.09).

CONCLUSIONS

In the largest contemporary MINOCA meta-analysis to date, patients with suspected MINOCA had a favorable prognosis compared with MI-CAD, but statistically nonsignificant trend toward worse outcomes compared to those with No-MI. Registration: URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42020145356.

MIKB: A manually curated and comprehensive knowledge base for myocardial infarction

Myocardial infarction knowledge base (MIKB; http://www.sysbio.org.cn/mikb/; latest update: December 31, 2020) is an open-access and manually curated database dedicated to integrating knowledge about MI to improve the efficiency of translational MI research. MIKB is an updated and expanded version of our previous MI Risk Knowledge Base (MIRKB), which integrated MI-related risk factors and risk models for providing help in risk assessment or diagnostic prediction of MI. The updated MIRKB includes 9701 records with 2054 single factors, 209 combined factors, 243 risk models, 37 MI subtypes and 3406 interactions between single factors and MIs collected from 4817 research articles. The expanded functional module, i.e. MIGD, is a database including not only MI associated genetic variants, but also the other multi-omics factors and the annotations for their functional alterations. The goal of MIGD is to provide a multi-omics level understanding of the molecular pathogenesis of MI. MIGD includes 1782 omics factors, 28 MI subtypes and 2347 omics factor-MI interactions as well as 1253 genes and 6 chromosomal alterations collected from 2647 research articles. The functions of MI associated genes and their interaction with drugs were analyzed. MIKB will be continuously updated and optimized to provide precision and comprehensive knowledge for the study of heterogeneous and personalized MI.

Randomized Evaluation of Beta Blocker and ACE-Inhibitor/Angiotensin Receptor Blocker Treatment for Post Infarct Angina in Patients With Myocardial Infarction With Non-obstructive Coronary Arteries: A MINOCA-BAT Sub Study Rationale and Design

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) occurs in ~10% of all patients with acute myocardial infarction (AMI), with an over-representation amongst women. Remarkably, it is estimated that as many as 1 in 4 patients with MINOCA experience ongoing angina at 12 months despite having no flow-restricting stenoses in their epicardial arteries. This manuscript presents the rationale behind Randomized Evaluation of Beta Blocker and Angiotensin-converting enzyme inhibitors/Angiotensin Receptor Blocker Treatment (ACEI/ARB) for Post Infarct Angina in MINOCA patients-The MINOCA BAT post infarct angina sub study. Methods: This trial is a registry-based, randomized, parallel, open-label, multicenter trial with 2 × 2 factorial design. The primary aim is to determine whether oral beta blockade compared with no oral beta blockade, and ACEI/ARB compared with no ACEI/ARB, reduce post infarct angina in patients discharged after MINOCA without clinical signs of heart failure and with left ventricular ejection fraction ≥40%. A total of 664 patients will be randomized into four groups; (i) ACEI/ARB with beta blocker, (ii) beta blocker only, (iii) ACEI/ARB only, or (iv) neither ACEI/ARB nor beta blocker and followed for 12 months. Results: The trial is currently recruiting in Australia and Sweden. Fifty six patients have been recruited thus far. Both sexes were equally distributed (52% women and 48% men) and the mean age was 56.3 ± 9.9 years. Conclusions: It remains unclear whether conventional secondary preventive therapies are beneficial to MINOCA patients in regard to post infarct angina. Existing registry-based literature suggest cardioprotective agents are less likely to be used in MINOCA patients. Thus, results from this trial will provide insights for future treatment strategies and guidelines specific to MINOCA patients.

Comparing pharmacotherapy in MINOCA versus medically managed obstructive acute coronary syndrome

Most prior studies have compared myocardial infarction with non-obstructive coronary arteries (MINOCA), to obstructive acute coronary syndrome (ACS) often requiring revascularisation. However, these were subject to treatment bias given the significant differences in management. This study uniquely compares the management and outcomes of MINOCA patients with a medically managed obstructive ACS (M-ACS) population. We retrospectively analysed registry data for consecutive patients admitted to the Gold Coast University Hospital with ACS requiring coronary angiography and identified patients with MINOCA and M-ACS. Baseline characteristics, pharmacological therapy and in-hospital outcomes were compared. In hospital outcomes were composite NACE, heart failure, stroke and major bleeding. Multivariate regression analysis was also performed to identify independent predictors of MINOCA. Multivariate regression analysis was also performed to identify independent predictors of MINOCA. We identified 139 patients with MINOCA and 142 patients with medically managed obstructive ACS (M-ACS). Multivariate regression analysis also identified female sex and cancer as independent predictors of MINOCA with odds ratios of 5.57 and 3.01, respectively. MINOCA patients were significantly less likely to receive cardioprotective medications at admission and discharge, specifically aspirin, beta-blockers, ACE-I and statins, compared to those with M-ACS. While mortality was higher among M-ACS patients (0.0% vs. 3.6%; p = 0.03), no significant differences were noted for composite NACE, heart failure, stroke and major bleeding. MINOCA patients have similar outcomes to M-ACS. Despite this, we noted a discrepancy in the use of cardioprotective medications. We also identified female sex and cancer were independent predictors of MINOCA. This may represent a missed opportunity to prevent adverse events among patients with MINOCA. Large, randomised trials are required to provide more definitive evidence.

Does Sex Influence Outcomes in Myocardial Infarction With Nonobstructive Coronary Arteries?

We examined differences in clinical profiles, predictors, and outcomes among patients with myocardial infarction (MI) with nonobstructive coronary arteries (MINOCAs) by sex. Data of 259 (132 males and 127 females) patients with MINOCA were consecutively collected. The primary clinical end point was major adverse cardiovascular events (MACE), including cardiovascular death, nonfatal MI, stroke, heart failure, and angina rehospitalization. Female patients with MINOCA were likely to be older than male patients with higher non-ST elevation myocardial infarction rate. Total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels were higher in female patients while male patients were more likely to have a smoking history, greater ST elevation myocardial infarction rate, higher diastolic blood pressure, and more alcohol use. During the 2-year follow-up, the incidence of MACE in males and females was similar (18% vs 20.2%, respectively; P = .673). The multivariable predictors of MACE in the female group were age, hypertension, and left ventricular ejection fraction (LVEF), whereas diabetes, smoking, and LVEF were multivariable predictors of MACE in the male group. In conclusion, there were differences in the clinical profiles between sexes. Clinical outcome was similar between male and female patients with MINOCA, whereas predictive risk factors varied.

Sex Differences in the Incidence and Outcomes of Acute Myocardial Infarction in Spain, 2016-2018: A Matched-Pair Analysis

(1) Background: Our aim was to analyze the incidence, procedures, and in-hospital outcomes of myocardial infarction (MI) in Spain (2016-2018) according to sex. (2) Methods: We estimated the incidence of an ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI) according to sex using the Spanish National Hospital Discharge Database. A matched-pair analysis was used. (3) Results: MI was coded in 156,826 patients aged ≥18 years (111,842 men and 44,984 women). Men showed higher incidence rates (205.0 vs. 77.8 per 100,000; p < 0.001; IRR = 2.81(95%CI:2.78-2.84)). After matching, the use of coronary artery by-pass grafting (CABG) (1.0% vs. 0.7%; p < 0.001) and percutaneous coronary intervention (PCI) (57.8% vs. 52.3%; p < 0.001) was higher among men with an STEMI, whereas the in-hospital mortality (IHM) remained higher among women (11.2% vs. 10.1%; p < 0.001). Likewise, CABG (1.9% vs. 3.3%; p < 0.001) and PCI (33.8% vs. 41.9%; p < 0.001) were less often used among women with an NSTEMI, but no sex-related differences were found in IHM. After adjusting for confounders, IHM was more than twofold higher for both men and women with an STEMI than those with an NSTEMI. Women with an STEMI had a 21% higher mortality risk than men (OR = 1.21(95%CI:1.13-1.29). (4) Conclusion: Men had higher incidence rates of MI than women. Women underwent invasive procedures less often and had a higher IHM when admitted for an STEMI.

Prognostic Value of GRACE Risk Scores in Patients With Non-ST-Elevation Myocardial Infarction With Non-obstructive Coronary Arteries

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a special type of myocardial infarction (MI). The GRACE risk score is commonly used to predict major adverse cardiovascular events (MACE) in non-ST-elevation myocardial infarction patients, and the suitability of the GRACE risk score for prognostic stratification in patients with MINOCA remains uncertain. This study aimed to investigate whether the GRACE risk score is capable of predicting MACE in MINOCA patients with NSTE. We calculated the GRACE risk score for 340 consecutive MINOCA patients with NSTE. Patients were divided into a low-intermediate risk group (≤ 140, 48.8%) and a high risk group (>140, 51.2%) according to their GRACE risk scores. The clinical characteristics and outcomes of the patients were assessed. Patients in the high risk group tended to be older and to have more comorbidities. At the 1-year follow-up, the rate of cardiac death in the high risk group was significantly higher than that in the low-intermediate-risk group (p = 0.010). There was no significant difference in non-fatal MI, stroke, heart failure, or cardiovascular-related rehospitalization. The incidence of total MACE was significantly higher in patients with high GRACE risk scores than in patients with low GRACE risk scores (p = 0.006). ROC curve analysis showed that the GRACE risk score has moderate value in predicting MACE in NSTE-MINOCA patients. The area under the ROC curve was 0.710 (95% CI 0.625–0.796, P < 0.001). The GRACE risk score provides potentially valuable prognostic information on clinical outcome when applied to MINOCA patients with NSTE.

Randomized evaluation of beta blocker and ACE-inhibitor/angiotensin receptor blocker treatment in patients with myocardial infarction with non-obstructive coronary arteries (MINOCA-BAT): Rationale and design

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is common and occurs in 6-8% of all patients fulfilling the diagnostic criteria for acute myocardial infarction (AMI). This paper describes the rationale behind the trial 'Randomized Evaluation of Beta Blocker and ACE-Inhibitor/Angiotensin Receptor Blocker Treatment (ACEI/ARB) of MINOCA patients' (MINOCA-BAT) and the need to improve the secondary preventive treatment of MINOCA patients. METHODS: MINOCA-BAT is a registry-based, randomized, parallel, open-label, multicenter trial with 2:2 factorial design. The primary aim is to determine whether oral beta blockade compared with no oral beta blockade, and ACEI/ARB compared with no ACEI/ARB, reduce the composite endpoint of death of any cause, readmission because of AMI, ischemic stroke or heart failure in patients discharged after MINOCA without clinical signs of heart failure and with left ventricular ejection fraction ≥40%. A total of 3500 patients will be randomized into four groups; e.g. ACEI/ARB and beta blocker, beta blocker only, ACEI/ARB only and neither ACEI/ARB nor beta blocker, and followed for a mean of 4 years. SUMMARY: While patients with MINOCA have an increased risk of serious cardiovascular events and death, whether conventional secondary preventive therapies are beneficial has not been assessed in randomized trials. There is a limited basis for guideline recommendations in MINOCA. Furthermore, studies of routine clinical practice suggest that use of secondary prevention therapies in MINOCA varies considerably. Thus results from this trial may influence future treatment strategies and guidelines specific to MINOCA patients.

Pharmacological therapy for the prevention of cardiovascular events in patients with myocardial infarction with non-obstructed coronary arteries (MINOCA): Insights from a multicentre national registry

AIMS

To assess the effect of pharmacological therapy on long-term prognosis of patients with MINOCA.

METHODS AND RESULTS

In this retrospective multicentre cohort study involving 9 Hub Hospitals across Italy we enrolled consecutive patients 18 years and older with diagnosis of MINOCA discharged from 1st March 2012 to 31st March 2018. Data on baseline characteristics and pharmacological therapy at discharge (ACEI/ARB, angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists; ASA, acetylsalicylic acid; beta-blockers; CCB, calcium-channel blockers; DAPT, dual anti-platelet therapy; statins), were collected systematically. The primary endpoint (PE) of the study was a composite of all cause death or acute myocardial infarction or acute coronary syndrome or heart failure leading to hospitalization or stroke. A total of 621 patients were included (mean [SD] age 65.1 [13.9] years; 344 [55.4%] female), of whom 106 (17.1%) experienced PE, including 27 patients (4.3%) who died. Multivariable analysis, after correction for all baseline differences, showed a significant association between pharmacological therapy at discharge and an increased risk of PE for aspirin (HR[95%CI] = 2.47[1.05-5.78], adjusted p = 0.04), whereas beta-blockers were associated with a significant benefit (HR[95%CI] = 0.49 [0.31-0.79], adjusted p = 0.02).

CONCLUSION

The use of beta-blockers was significantly associated to a less frequent occurrence of adverse outcomes at long-term follow-up among patients with MINOCA, whereas ASA displayed a potentially harmful impact on prognosis. The findings in the study may be relevant for the design of future studies which should take into account possible heterogeneity among MINOCA patients.

Malignancy in patients with myocardial infarction and non-obstructive coronary arteries: A systematic review and meta-regression

BACKGROUND

The significance of malignancy in patients with myocardial infarction and non-obstructive coronary arteries (MINOCA) is poorly defined. This study aimed at determining the prevalence of malignancy and its association with long-term outcome in MINOCA.

METHODS

We searched the MEDLINE, EMBASE, and CENTRAL databases up to March 31, 2020 to identify studies reporting data on malignancy in full. We performed a random effects meta-analysis of proportions and assessed statistical heterogeneity using the I2 statistic and meta-regression analysis.

RESULTS

A total of 9 studies including 26,636 patients (11,910 men and 14,726 women) were selected for the meta-analysis. Of them, 655 patients (2.5%) had a diagnosis of malignancy at presentation. Comparison of presenting features and outcome between patients with MINOCA and patients with myocardial infarction and coronary artery disease (MI-CAD) showed that malignancy was significantly more common in the former as compared with the latter (p = 0.019). During a median follow-up of 39 months, 2,081 patients with MINOCA died (7.8%). Meta-regression analysis demonstrated that long-term mortality was associated with left ventricular ejection fraction (p = 0.0001; coefficient: -0.001; 95% CI: from -0.002 to 0.002), malignancy at presentation (p = 0.01; coefficient: 0.001; 95% CI: from -0.001 to 0.001), and use of beta-blockers during follow-up (p = 0.03; coefficient: 0.001; 95% CI: from -0.000 to 0.001).

CONCLUSION

This study shows that the prevalence of malignancy in patients with MINOCA is not trivial and is significantly greater than in patients with MI-CAD. Malignancy is significantly associated with an unfavorable long-term prognosis in MINOCA.

Myocarditis in Relation to Angiographic Findings in Patients With Provisional Diagnoses of MINOCA

OBJECTIVES

The aim of this study was to determine the prevalence of myocarditis among patients presenting with myocardial infarction with nonobstructive coronary arteries (MINOCA) in relation to the angiographic severity of nonobstructive coronary artery disease (CAD).

BACKGROUND

MINOCA represents about 6% of all cases of acute myocardial infarction. Myocarditis is a diagnosis that may be identified by cardiac magnetic resonance (CMR) imaging in patients with a provisional diagnosis of MINOCA.

METHODS

A systematic review was performed to identify studies reporting the results of CMR findings in MINOCA patients with nonobstructive CAD or normal coronary arteries. Study-level and individual patient data meta-analyses were performed using fixed- and random-effects methods.

RESULTS

Twenty-seven papers were included, with 2,921 patients with MINOCA; CMR findings were reported in 2,866 (98.1%). Myocarditis prevalence was 34.5% (95% confidence interval [CI]: 27.2% to 42.2%) overall and was numerically higher in studies that defined MINOCA as myocardial infarction with angiographically normal coronary arteries compared with a definition that permitted nonobstructive CAD (45.9% vs. 32.3%; p = 0.16). In a meta-analysis of individual patient data from 9 of the 27 studies, the pooled prevalence of CMR-confirmed myocarditis was greater in patients with angiographically normal coronary arteries than in those with nonobstructive CAD (51% [95% CI: 47% to 56%] vs. 23% [95% CI: 18% to 27%]; p < 0.001). Men and younger patients with MINOCA were more likely to have myocarditis. Angiographically normal coronary arteries were associated with increased odds of myocarditis after adjustment for age and sex (adjusted odds ratio: 2.30; 95% CI: 1.12 to 4.71; p = 0.023).

CONCLUSIONS

Patients with a provisional diagnosis of MINOCA are more likely to have CMR findings consistent with myocarditis if they have angiographically normal coronary arteries.

Sex Disparities in Myocardial Infarction: Biology or Bias?

Women have generally worse outcomes after myocardial infarction (MI) compared to men. The reasons for these disparities are multifactorial. At the beginning is the notion-widespread in the community and health care providers-that women are at low risk for MI. This can impact on primary prevention of cardiovascular disease in women, with lower use of preventative therapies and lifestyle counselling. It can also lead to delays in presentation in the event of an acute MI, both at the patient and health care provider level. This is of particular concern in the case of ST elevation MI (STEMI), where "time is muscle". Even after first medical contact, women with acute MI experience delays to diagnosis with less timely reperfusion and percutaneous coronary intervention (PCI). Compared to men, women are less likely to undergo invasive diagnostic testing or PCI. After being diagnosed with a STEMI, women receive less guideline-directed medical therapy and potent antiplatelets than men. The consequences of these discrepancies are significant-with higher mortality, major cardiovascular events and bleeding after MI in women compared to men. We review the sex disparities in pathophysiology, risk factors, presentation, diagnosis, treatment, and outcomes for acute MI, to answer the question: are they due to biology or bias, or both?

Myocardial Infarction with Nonobstructive Coronary Arteries (MINOCA): A Review of the Current Position

Myocardial infarction with nonobstructive coronary arteries (MINOCA) remains a puzzling clinical entity that is characterized by clinical evidence of myocardial infarction (MI) with normal or near-normal coronary arteries on angiography (stenosis <50%). Major advances in understanding this condition have been made in recent years. The precise pathogenesis is poorly understood and is being studied and examined further. Guidelines indicate that MINOCA is a group of heterogeneous diseases with different mechanisms of pathology. Since there are multiple possible pathological mechanisms, it is not certain that the classical secondary prevention and treatment strategy for MI with obstructive coronary artery disease (MI-CAD) is optimal for MINOCA patients. The prognosis and predictors for MINOCA patients remain unclear. Although the prognosis is slightly better for MINOCA patients than for MI-CAD patients, MINOCA isn't always benign. The aim of this paper was to review the literature and evaluate MINOCA epidemiology, clinical features, etiology, diagnosis, treatment, and prognosis.

MINOCA: The caveat of absence of coronary obstruction in myocardial infarction

AIMS

Whether patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) have better outcomes than patients with obstructive coronary artery disease remains contradictory. The current study focussed on the clinical profile and prognosis of MINOCA patients.

METHODS AND RESULTS

We performed a retrospective analysis of patients with acute coronary syndrome (ACS) admitted to the Isala hospital in Zwolle, the Netherlands, between 2006 and 2014. A total of 7693 patients were categorized into three groups: MINOCA, single-vessel obstructive ACS (SV-ACS), and multi-vessel obstructive ACS (MV-ACS). MINOCA patients (5.2% of the total population) were more likely to be female (51.5% vs. 30.3% and 26.0% in SV-ACS and MV-ACS, respectively, p < 0.001 for both). The prevalence of risk factors in the MINOCA group was in between the SV-ACS and MV-ACS groups. Logistic regression revealed a lower odds of dying in SV-ACS (odds ratio (OR) = 0.70 (p = 0.04)) and a similar odds in MV-ACS (OR = 0.88, p = 0.45) compared to MINOCA.

CONCLUSIONS

Patients with MINOCA show an 'intermediate' risk profile with mortality rates in between those of both ACS groups. Hence, MINOCA should be recognised as a potential risk factor for mortality, requiring adequate treatment and follow-up.

Diagnostic coronary angiography and percutaneous coronary intervention practices in New Zealand: The All New Zealand Acute Coronary Syndrome-Quality Improvement CathPCI registry 3-year study (ANZACS-QI 37)

BACKGROUND

Coronary heart disease remains one of the leading causes of mortality and morbidity in New Zealand (NZ) and globally. The All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) programme includes the CathPCI registry which records all those referred for diagnostic coronary angiography (DCA) and percutaneous coronary intervention (PCI) in NZ. We present the methods and three-years of data from the ANZACS-QI CathPCI registry.

METHODS

The data was extracted from the ANZACS QI CathPCI registry from 01/09/2014 to 24/09/2017. The ANZACS-QI data dictionary defines all the clinical, procedural and outcomes variables collected, and standard statistical analyses were applied.

RESULTS

40,870 patients underwent cardiac catheterisation, with a mean age of 65 years, and males making up 67% of the cohort. Indications included acute coronary syndrome 55%, angina with suspected stable coronary disease 28%, valve surgery workup 8%, planned PCI 3%, heart failure/cardiomyopathy 3%, arrhythmia 1% and other 2%. For those undergoing DCA alone, radial access was used in 85% and two-thirds had at least one major artery with >50% stenosis. PCI was performed in 39% of patients. Drug-eluting stents were used in 97%.

CONCLUSION

The CathPCI registry records the characteristics and outcomes of all patients undergoing DCA and PCI in NZ hospitals. As part of the ANZACS-QI programme the registry provides an important platform for quality improvement, research and to inform clinical practice.

Increases in early discharge following acute coronary syndrome hospitalisations and associated clinical outcomes in New Zealand between 2006 and 2015: ANZACS-QI-43 study

BACKGROUND

International guidelines recommend early discharge for uncomplicated acute coronary syndrome (ACS) patients within 3 days; however, there is a paucity of contemporary literature regarding the safety of this strategy.

AIMS

To report the trends in the proportion of ACS hospitalisations discharged within 3 days and their outcomes in New Zealand.

METHODS

ACS hospitalisations 2006-2015 using national routinely collected data were categorised by length of stay (LOS) into ≤3, 4-5 and >5 days, excluding deaths during the index admission. Trend analysis of death, cardiovascular and bleeding events and their composites (net adverse clinical events) at 30-day and 1-year post-discharge were performed using generalised linear mixed regression models adjusting for covariates by LOS subgroups.

RESULTS

Among 130 037 ACS hospitalisations, LOS ≤ 3 days increased from 32% in 2006 to 44% in 2016. This trend was observed for all demographics, ACS subtypes and management strategies. Event rates at 30 days and 1 year were the lowest for the LOS ≤3 days subgroup (all-cause mortality 1.6% and 9.1% respectively). Thirty-day and 1-year all-cause mortality rates were unchanged over time for this subgroup (adjusted odds ratio (95% confidence interval) of 1.011 (0.985-1.038) and 0.991 (0.979-1.003)), while net adverse clinical event rates significantly decreased (0.962 (0.950-0.973) and 0.972 (0.964-0.980) respectively).

CONCLUSION

There was a substantial increase in early discharge post-ACS over 10 years. These patients were associated with reduction in adverse clinical events up to 1 year and no increase in all-cause mortality. These findings from a comprehensive national register suggest that guideline recommendations on early discharge after uncomplicated ACS are safe and appropriate.

Myocardial infarction with non-obstructive coronary arteries as compared with myocardial infarction and obstructive coronary disease: outcomes in a Medicare population

AIMS

The prognosis of patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) is poorly understood. We examined major adverse cardiac events (MACE) defined as all-cause mortality, re-hospitalization for acute myocardial infarction (AMI), heart failure (HF), or stroke 12-months post-AMI in patients with MINOCA versus AMI patients with obstructive coronary artery disease (MICAD).

METHODS AND RESULTS

Multicentre, observational cohort study of patients with AMI (≥65 years) from the National Cardiovascular Data Registry CathPCI Registry (July 2009-December 2013) who underwent coronary angiography with linkage to the Centers for Medicare and Medicaid (CMS) claims data. Patients were classified as MICAD or MINOCA by the presence or absence of an epicardial vessel with ≥50% stenosis. The primary endpoint was MACE at 12 months, and secondary endpoints included the components of MACE over 12 months. Among 286 780 AMI admissions (276 522 unique patients), 16 849 (5.9%) had MINOCA. The 12-month rates of MACE (18.7% vs. 27.6%), mortality (12.3% vs. 16.7%), and re-hospitalization for AMI (1.3% vs. 6.1%) and HF (5.9% vs. 9.3%) were significantly lower for MINOCA vs. MICAD patients (P < 0.001), but was similar between MINOCA and MICAD patients for re-hospitalization for stroke (1.6% vs. 1.4%, P = 0.128). Following risk-adjustment, MINOCA patients had a 43% lower risk of MACE over 12 months (hazard ratio = 0.57, 95% confidence interval 0.55-0.59), in comparison to MICAD patients. This pattern was similar for adjusted risks of the MACE components.

CONCLUSION

This study confirms an unfavourable prognosis in elderly patients with MINOCA undergoing coronary angiography, with one in five patients with MINOCA suffering a major adverse event over 12 months.