Possible causes of heart attack without coronary artery blockages.

Not Applicable

Recruiting

• Conditions: Myocardial Infarction; Cardiovascular - Coronary heart disease

• Registration Number: ACTRN12618001533280
• Lead Sponsor: The University of Adelaide

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2018-09-13
• Last Update Posted: 5 January 2021

Recruitment & Eligibility

• Status: Recruiting
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

1) Patients presenting with the symptoms suggestive of acute non-ST elevation myocardial infarction (NSTEMI) will be approached to participate in this study.
2) Male/Female, Aged equal or above 18 years
3) Acute MI Criteria (Must meet both of the following criteria (a & b)
a) Troponin I or T level greater than the 99th percentile of the upper reference limit (URL)
b) No significant ST segment elevation in ECG
4) Coronary angiography diagnosis of non-obstructive coronary arteries ( less than 50% stenosis or completely normal arteries)

Exclusion Criteria

1) ST-segment elevation on ECG (ie: STEMI)
2) Thrombolytic therapy within 48 hours of diagnostic angiography.
3) Troponin elevation due to non-ischaemic causes identified prior to coronary angiography
4) Coronary angiography revealing obstructive coronary arteries (above or equal to 50% stenosis)
5) Severe valvular disease – including aortic stenosis (valve gradient more than 50mmHg) mitral regurgitation (regurgitation extending to pulmonary veins), mitral stenosis (valve are less than 1cm2)
6) Significant left ventricular dysfunction as documented by an ejection fraction less than 40%
7) Severe obstructive airways – any prior admission to ICU or general hospital admission in past 12 months for infective exacerbation of airways disease.
8) Active internal bleeding or history of hemorrhagic diathesis (including heparin-induced thrombocytopenia)
9) Major surgery (eg: CABG) or trauma within the previous 6 weeks
10) Non-English speaking
11) Pregnancy
12) Inability to provide informed consent (Compromised mental status, e.g., dementia, too ill)
13) Currently a prisoner
14) Contraindications to drugs and devices (Adenosine, GTN, OCT wire, Combo wire)

Study & Design

• Study Type: Observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To determine the prevalence of coronary microvascular dysfunction as determined by an abnormal HMR (HMR>1.9) in MINOCA patients, during their acute presentation.<br><br>The ComboWire is a steerable guidewire with a pressure transducer mounted proximal to the tip and a tip mounted ultrasound transducer. The ComboWire measures pressure and flow velocity when used with the ComboMap Instrument. HMR will be calculated as the ratio between hyperaemic mean distal pressure and hyperaemic average Doppler flow peak velocity (APV). The calculations will be driven from ComboMap system in a semi-automated manner.[In-Hospital]