Implantable Cardiac Monitor to Detect Atrial Fibrillation in Patients With MINOCA

Study Overview
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Brief Summary
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Myocardial infarction with non-obstructive coronary arteries (MINOCA) (i.e.<50% stenoses) on coronary angiography) is an underappreciated clinical entity concerning 5-6% of patients with acute myocardial infarction. Approximately 50% of these patients remain without appropriate diagnosis and treatment. The MINOCA study aims at systematically assessing the frequency of underlying pathologies of MINOCA and outcomes with a multidisciplinary etiologic work-up and follow-up of 5 years including, for the first time, an implantable cardiac monitor (ICM) to assess the frequency of atrial fibrillation as underlying cause for MINOCA.

Detailed Description
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Approximately 5-6% of patients with acute myocardial infarction (AMI) have myocardial infarction with non-obstructive coronary arteries (MINOCA) (i.e.<50% stenoses) on coronary angiography and up to 50% of these patients remain without appropriate diagnosis and treatment. A multidisciplinary etiologic work-up of MINOCA has recently been proposed by international consensus documents. The present study aims for a structured scientific data collection from a full guideline-based work-up after MINOCA and follow-up of 5 years to assess clinical outcomes. Untreated atrial fibrillation is a potentially neglected underlying cause of MINOCA. As implantable cardiac monitors (ICM) can detect atrial fibrillation with high accuracy, the aim of this study is, for the first time, to assess the occurrence of first diagnosed atrial fibrillation with the use of ICM in patients with MINOCA. To allow for an all-comers data collection, patients with contraindication(s) to ICM implantation will be enrolled into the non-ICM group to assess the frequency of underlying causes of MINOCA and clinical outcomes throughout 5 years.

Official Title
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Implantable Cardiac Monitor to Detect Atrial Fibrillation in Patients With MINOCA

Conditions
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MINOCA, Atrial Fibrillation

Intervention / Treatment
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* Device: CONFIRM Rx implantable cardiac rhythm monitor (Abbott)
* Diagnostic Test: Systematic etiologic work-up for underlying causes of MINOCA


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria ICM group ≥18 years of age Written informed consent Acute myocardial infarction (AMI) type 1 in accordance with the 4th universal definition of myocardial infarction Non-obstructive coronary arteries on angiography defined as the absence of coronary artery stenoses ≥50% in any potential infarct-related artery No clinically overt specific cause for the acute presentation Subendocardial or transmural late gadolinum enhancement (LGE) consistent with an ischemic etiology on cardiac magnetic resonance imaging (CMR) No clear underlying cause of MINOCA and therefore increased probability of atrial fibrillation Exclusion Criteria ICM group: Known atrial fibrillation or atrial flutter History of atrial fibrillation or atrial flutter ablation Known coronary artery disease Previous MI Previous percutaneous coronary intervention (PCI) Previous coronary artery bypass grafting (CABG) Contraindications to CMR (i.e. non-MR-compatible implantable cardiac device, glomerular filtration rate (GFR) <30 ml/min) Contraindications to ICM implantation Clear underlying cause of MINOCA before ICM implantation Inclusion Criteria non-ICM group: ≥18 years of age Written informed consent AMI type 1 in accordance with the 4th universal definition of myocardial infarction Non-obstructive coronary arteries on angiography defined as the absence of coronary artery stenoses ≥50% in any potential infarct-related artery No clinically overt specific cause for the acute presentation Subendocardial or transmural LGE consistent with an ischemic etiology on CMR Exclusion Criteria non-ICM group: Known coronary artery disease Previous MI Previous PCI Previous CABG Contraindications to CMR (i.e. non-MR-compatible implantable cardiac device, GFR <30 ml/min)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ICM group<br>Patients eligible for ICM implantation for screening of atrial fibrillation | Device: CONFIRM Rx implantable cardiac rhythm monitor (Abbott)<br>* Implantation of CONFIRM Rx ICM<br>Diagnostic Test: Systematic etiologic work-up for underlying causes of MINOCA<br>* Intracoronary optical coherence tomography, cardiac magnetic resonance imaging, transesophageal echocardiography, vasospasm testing, thrombophilia screening, Holter ECG (only non-ICM group)<br>|
| Non-ICM group<br>Patients ineligible for ICM implantation due to 1) refusal, 2) contraindication, or 3) clear underlying cause of MINOCA before ICM implantation. | Diagnostic Test: Systematic etiologic work-up for underlying causes of MINOCA<br>* Intracoronary optical coherence tomography, cardiac magnetic resonance imaging, transesophageal echocardiography, vasospasm testing, thrombophilia screening, Holter ECG (only non-ICM group)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ICM group: Atrial fibrillation | The occurrence of first diagnosed atrial fibrillation in patients with MINOCA according to ICM | 1 year | 
| Non-ICM group: Frequency of underlying causes of MINOCA | The frequency of underlying causes of MINOCA (i.e. plaque rupture, plaque erosion, coronary thrombus, coronary dissection, eruptive calcific nodule, coronary spasm (including microvascular dysfunction), coronary thromboembolism due to intra- or extracardiac sources of thrombi (including thromboembolism in the context of a persistent foramen ovale (PFO)), atrial fibrillation according to 3 7-day-Holter-ECGs, other sources of coronary embolism (e.g. vegetations, complex aortic plaques), and arterial thrombophilia | 1 year | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ICM group: Time to first diagnosed atrial fibrillation | Time to first occurrence of atrial fibrillation according to ICM |  2 years (battery end of life or explantation of ICM) | 
| ICM group: Time to different durations of first diagnosed atrial fibrillation | Time to first diagnosis of atrial fibrillation (lasting ≥30 seconds; ≥6 minutes; ≥1 hour; ≥ 24 hour) |  2 years (battery end of life or explantation of ICM) | 
| ICM group: Atrial fibrillation burden | Time spent in atrial fibrillation divided by total rhythm monitoring time x100 (%) |  2 years (battery end of life or explantation of ICM) | 
| ICM group: First diagnosis of atrial fibrillation, stroke or death | Time to composite of first diagnosis of atrial fibrillation, stroke or death | 1 year | 
| ICM group: Other brady- or tachyarrhythmias | The incidence and time to first occurrence of other brady- or tachyarrhythmias |  2 years (battery end of life or explantation of ICM) | 
| ICM group: Predictive value of CMR parameters for atrial fibrillation | Predictive value of atrial parameters of CMR imaging for the diagnosis of atrial fibrillation |  2 years (battery end of life or explantation of ICM) | 
| ICM group: Frequency of non atrial fibrillation related etiologies of MINOCA | The frequency of non atrial fibrillation related etiologies of MINOCA (i.e. plaque rupture, plaque erosion, coronary thrombus, coronary dissection, eruptive calcific nodule, coronary spasm (including microvascular dysfunction), coronary thromboembolism due to other intra- or extracardiac sources of thrombi not related to atrial fibrillation (including thromboembolism in the context PFO), other sources of coronary embolism (e.g. vegetations, complex aortic plaques), and arterial thrombophilia | 1 year | 
| Both groups: Clinical outcomes | The occurrence of all-cause death, cardiac death, myocardial infarction, coronary revascularization, stroke, transitory ischemic attack, deep vein thrombosis, pulmonary embolism, and systemic arterial thromboembolism | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Implantable cardiac monitor