Logistical reasons and slow recruitment

Myocardial infarction (MI) frequently recurs after non-ST elevation MI (NSTEMI) that may be related to insufficient vulnerable plaque identification using invasive coronary angiography. Furthermore, the natural behaviour of vulnerable plaques in NSTEMI over time and their relation with biomarkers need further exploration. More accurate identification and assessing long-term behaviour of vulnerable plaques may improve therapeutic strategies and clinical outcome. The investigators hypothesize that fully integrated 18Fluoride Sodium-Fluoride (18F-NaF) Positron Emission Tomography/Cardiac Magnetic Resonance imaging (PET/CMR) increases the ability to detect vulnerable plaques as compared to coronary angiography.

This prospective study in 33 consecutive patients with NSTEMI aims to:

1. Compare coronary vulnerable plaque detection between 18F-NaF PET/CMR and invasive coronary angiography,
2. Investigate the correlation of coronary vulnerable plaques using 18F-NaF PET with myocardial infarction using CMR, both at baseline and during follow-up,
3. Examine systemic arterial 18F-NaF-uptake using PET/CMR and their relation with systemic events (cerebrovascular accidents, transient ischemic attacks, or peripheral arterial disease), and
4. Examine the relation between vulnerable plaques and plasma biomarkers.

Inclusion Criteria:

• Prolonged symptoms suspected of cardiac origin (angina pectoris or angina equivalent), and presentation on the cardiac emergency department <24 hours after symptom onset
• Elevated levels of high-sensitivity troponin T (>14ng/L; initial blood sample at presentation or a second sample 3 hours after presentation)
• Only patients scheduled for invasive coronary angiography
• Age 18 years - 85 years
• Mentally competent
• Informed written consent

Exclusion Criteria:

• Conservatively managed patients who are not scheduled for invasive coronary angiography
• Refractory angina or on-going severe ischemia requiring immediate invasive coronary angiography
• Patients requiring invasive coronary angiography < 24 hours after admission
• Hemodynamic instability and cardiogenic shock (mean arterial pressure < 60 mmHg)
• Severe heart failure (Killip Class ≥ III)
• ST elevation myocardial infarction (ST-elevation in 2 contiguous leads: ≥0.2mV in men or ≥0.15 mV in women in leads V2-V3 and/or ≥0.1 mV in other leads or new left bundle branch block)
• Chest pain highly suggestive of non-cardiac origin (as judged by the cardiac emergency department physician/cardiologist):
• (Suspicion of) acute aortic dissection, acute pulmonary embolism, acute peri-myocarditis
• Life threatening arrhythmias on the cardiac emergency department or prior to presentation (sustained ventricular tachycardia, repetitive non-sustained ventricular tachycardia, ventricular fibrillation, sino-artial or atrio-ventricular block)
• Atrial fibrillation with ventricular rate ≥100 beats per minute (bpm)
• Tachycardia (≥100/bpm)
• Angina pectoris secondary to anaemia (<5.6 mmol/L), untreated hyperthyroidism, or severe hypertension (>200/110 mmHg)
• More than mild aortic and mitral valve calcification or stenosis by latest echocardiography
• Pregnancy
• Breast feeding women
• Life expectancy <2 years (malignancy, etc.)
• Refusal of data storage until 15 years after end of study
• Participation in another investigational study that has not reached its primary endpoint
• Contraindications to cardiac magnetic resonance imaging

Thirty-three patients, 18-85 years old and admitted with non-ST elevation myocardial infarction (NSTEMI). After informed consent, patients wil receive standard, guideline-based clinical care that includes invasive coronary angiography. Plasma biomaker will be sampled serially, and a comprehensive Sodium 18F-Fluoride Positron Emission Tomography/Cardiac Magnetic Resonance imaging (18F-NaF PET/CMR) will be performed at baseline (<72 hours) and at 6 months, or earlier when patients suffer recurrent myocardial infarction < 6months. Patients will be followed for one year during regular outpatient clinic visits.