A Study to Analyze the Role of Sympathetic Nervous System in Spontaneous Coronary Artery Dissection

Study Overview
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Brief Summary
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The purpose of this research is to compare sympathetic function (flight or fight system) and arterial health including structure and mechanics of participants with history of spontaneous coronary artery dissection (SCAD) to age and sex matched control participants.

Official Title
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Role of the Neurovascular System in Spontaneous Coronary Artery Dissection (SCAD)

Conditions
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Spontaneous Coronary Artery Dissection, Healthy

Intervention / Treatment
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* Other: Arterial Tonometry
* Diagnostic Test: Echocardiogram
* Diagnostic Test: Carotid Ultrasounds
* Diagnostic Test: Elastography
* Other: Ankle-Brachial Index
* Other: Microneurography with sympathoexcitatory maneuvers


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For SCAD patients: history of SCAD as confirmed by coronary angiography or cardiac computed tomography angiography For controls: no cardiac disease history Exclusion Criteria: Pregnancy Known or suspected unstable cardiac condition within 4 weeks of the study Active treatment with anticoagulation or dual antiplatelet therapy Prisoner

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Health Services Research
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Spontaneous coronary artery dissection (SCAD) group<br>Subject with a history of SCAD will undergo a series of diagnostic studies to assess neurovascular function. | Other: Arterial Tonometry<br>* We will measure arterial stiffness using arterial tonometry.<br>Diagnostic Test: Echocardiogram<br>* We will collect limited ultrasound images of the heart.<br>Diagnostic Test: Carotid Ultrasounds<br>* We will perform ultrasound imaging of the carotid artery.<br>Diagnostic Test: Elastography<br>* We will measure the elastic properties of the arteries using elastography.<br>Other: Ankle-Brachial Index<br>* We will measure the ankle-brachial index to assess peripheral artery blood flow.<br>Other: Microneurography with sympathoexcitatory maneuvers<br>* We will measure sympathetic nerve activity at rest and in response to isometric handgrip, mental stress test, cold pressor test, Valsalva maneuvers.<br>|
| Other: Healthy Control Group<br>Healthy subjects will undergo a series of diagnostic studies to assess neurovascular function. | Other: Arterial Tonometry<br>* We will measure arterial stiffness using arterial tonometry.<br>Diagnostic Test: Echocardiogram<br>* We will collect limited ultrasound images of the heart.<br>Diagnostic Test: Carotid Ultrasounds<br>* We will perform ultrasound imaging of the carotid artery.<br>Diagnostic Test: Elastography<br>* We will measure the elastic properties of the arteries using elastography.<br>Other: Ankle-Brachial Index<br>* We will measure the ankle-brachial index to assess peripheral artery blood flow.<br>Other: Microneurography with sympathoexcitatory maneuvers<br>* We will measure sympathetic nerve activity at rest and in response to isometric handgrip, mental stress test, cold pressor test, Valsalva maneuvers.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial thickness | Measured by carotid ultrasound intimal media thickness reporting in mm | Baseline | 
| Arterial stiffness | Measured by carotid ultrasound pulse wave velocity reporting in m/s | Baseline | 
| Baroreflex sensitivity | The slope between heart rate and blood pressure at rest and during the Valsalva Maneuver (ms/mmHg) | Baseline | 
| Sympathetic response to stress | Blood pressure or muscle sympathetic nerve activity response to sympathoexcitatory stressors (mm/Hg or bursts/min). | Baseline |