None listed
Conditions
Brief summary
The aim of this study is to compare invasive (meaning it is done from inside the body) assessment of blood flow through the large and small arteries of the heart to the heart muscle (via angiography) and a single proton emission computed tomography with low dose CT (SPECT/CT) scan assessing the same thing. This is because SPECT/CT assessment of blood flow to the heart through small arteries is a relatively new technology that we would like use more if the results of this study deem it to be accurate. Presently it is difficult to assess whether there are abnormalities of the small arteries of the heart, which is a common cause of chest pain in people who are diagnosed as having “normal coronary arteries”. The only way to do this currently is with an invasive test, using special pressure wires to measure blood flow in the small arteries. This would mean that patients with chest pain could have a SPECT/CT scan alone rather than an angiogram (requiring a procedure with inherent risks) to investigate their symptoms. Involvement in this study involves addition of a pressure wire test to the normal heart angiogram procedure, along with a SPECT/CT scan. Additionally, participants will be checked in on at 1 and 12 months following their tests to assess their progress, whether they have had any heart problems, how their symptoms are, and whether they have had any further tests or diagnoses. This will all help to assess how useful the SPECT/CT scan will be in the future.
Interventions
The study aims to assess the correlation between single proton emission computed tomography/computed tomography (SPECT/CT) myocardial flow reserve with invasive coronary flow reserve in patients with both normal coronary angiography and intermediate lesions (intermediate lesions are those with 50-70% stenosis severity) on coronary angiography warranting further investigation.
Patients will be recruited immediately prior to coronary angiography indicated for the investigation of ischaemic chest p
The study aims to assess the correlation between single proton emission computed tomography/computed tomography (SPECT/CT) myocardial flow reserve with invasive coronary flow reserve in patients with both normal coronary angiography and intermediate lesions (intermediate lesions are those with 50-70% stenosis severity) on coronary angiography warranting further investigation. Patients will be recruited immediately prior to coronary angiography indicated for the investigation of ischaemic chest pain and either (1) normal epicardial vessels but symptoms suggestive of myocardial ischaemia, or (2) abnormal single epicardial vessel on coronary angiography with lesions of indeterminate significance warranting further evaluation with functional investigations prior to a decision regarding percutaneous revascularisation. The aim will be to recruit 20 patients in each group. Patients in group 1 will have invasive coronary flow reserve (CFR)/index of microvascular resistance (IMR) measures in their left anterior descending and right coronary arteries. Patients in group 2 will have fractional flow reserve (FFR), CFR and IMR performed in the vessel containing the lesion along with the non-culprit vessel (left anterior descending or right coronary artery). All patients will then have SPECT/CT scans within 7 days of their coronary angiogram, with assessment of SPECT-coronary flow reserve. The CFR, IMR and FFR assessments will be performed as a 10-15 minute additional assessment as part of their clinically indicated coronary angiogram which takes place as a day procedure. The CFR and IMR assessments are specific to the study, the FFR would be performed as part of clinical practice. These assessments will be performed according to protocols used by local hospital cardiologists for all such assesments in clinical and research studies. The SPECT/CT scan will require an additional 1-2 hour visit to the hospital. It is an additional assessment which would not routinely be performed for these patients but which may provide additional clinically relevant information. The SPECT/CT scan will be performed according to local hospital protocol. The correlation between these investigations will be assessed. Additionally, patients will be contacted at 30 days and 12 months by the study investigators to enquire about outcomes, particularly major adverse cardiac events; ongoing symptoms attributable to myocardial ischaemia; and further investigations/diagnoses made subsequent to the invasive and SPECT myocardial flow reserve studies.
Sponsors
Abbott Vascular
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Patients referred for coronary angiography for investigation of ischaemic chest pain. Inclusion criteria for group 1 is that they have normal epicardial vessels (<30% diameter stenosis) who will undergo invasive coronary flow reserve (CFR) and index of microvascular resistance (IMR) at the time of coronary angiogram. Inclusion criteria for group 2 is that they have a moderate-severe lesion on coronary angiogram in either the RCA or LAD, who will undergo fractional flow reserve (FFR), CFR and IMR in both the culprit and non-culprit vessel.
Exclusion criteria
- Patients with a rise in high-sensitivity troponin I in concert with their ischaemic symptoms - Pregnant and breastfeeding women, due to the radiation exposure inherent to this study - Patients with allergies to iodine contrast - Patients with contraindications to adenosine including: asthma/bronchospasm, greater than first degree heart block or sick sinus syndrome without a pacemaker, symptomatic aortic stenosis or hypertrophic cardiomyopathy, hypotension (SBP < 90 mmHg), unstable angina, cerebral ischaemia or current dipyridamole medication use. - Patients with previous evidence of myocardial infarction (such as history of STEMI, NSTEMI) or baseline perfusion abnormalities on SPECT to suggest previous myocardial infarction given it may impact the measurements of FFR/CFR/IMR).
Outcome results
None listed