Ischemic heart disease is currently a leading cause of morbidity and mortality in the US 1 In recent decades, impressive advancements have been made in the diagnosis and treatment of coronary artery disease (CAD). Morbidity and mortality from CAD and its related complications, unfortunately, remain high in part due to the increasing prevalence of obesity and type 2 diabetes. Nuclear cardiovascular imaging is a major player in the diagnosis and management of CAD. Myocardial perfusion imaging (MPI) in particular, fills an important role in its diagnosis, especially in patients of intermediate risk based on tradition risk factors, as well as assessment of risk for cardiac death or acute ischemic events in those with established disease. With its wide availability as well as wealth of data backing its utility, single photon emission computed tomography (SPECT) has been the dominant myocardial perfusion imaging modality used for the diagnosis of CAD as well as risk stratification of patients with known disease. However, positron emission tomography (PET)-based MPI (Figures ?(Figures11 and ?and2)2) has increasing evidence to show its diagnostic utility and additive prognostic value.

  • PET is an effective imaging modality for the diagnosis of coronary artery disease as well as assessing prognosis in patients with known disease.

  • PET is the most sensitive modality to assess myocardial viability and provides an important tool in assessing the benefit of revascularization in patients with ischemic cardiomyopathy.

  • Several exciting additions including molecular imaging and introduction of new imaging tracers are likely to increase the future use of cardiac PET

  • PET myocardial perfusion imaging (MPI) is a powerful tool in the diagnosis of coronary artery disease and assessing prognosis for those with known disease. There is evidence showing its superior diagnostic and prognostic potential compared to conventional SPECT MPI in patients with coronary disease.

  • Information from myocardial blood flows allow early detection of coronary disease in certain groups of patients at high risk of CAD, such as diabetics and postmenopausal women.

  • PET MPI can produce higher image quality and interpretive certainty compared to SPECT MPI, and studies are done in less time with less radiation exposure to patients.

  • Due to short half-life of the tracer, 82Rb PET MPI studies cannot be done with exercise.

  • Patients referred for MPI and unable to exercise should be considered for PET. This is especially true for obese patients whose body habitus may be problematic with other MPI modalities.

  • PET is also useful for assessment of myocardial viability in patients with ischemic cardiomyopathy.

  • Exciting opportunities are arising in molecular imaging which may increase the use of PET imaging for ischemic heart disease in the future.

Compared to conventional SPECT myocardial perfusion imaging, PET provides superior accuracy in the diagnosis of coronary artery disease, and with the incorporation of myocardial blood flow and coronary flow reserve it adds value in assessing prognosis for patients with established coronary and microvascular disease. Further, with exciting developments in new PET radiotracers, advances in molecular imaging, and progress in hybrid imaging with CT or MRI, PET based imaging will continue to play a prominent role in evaluation of ischemic heart disease.

 

Keywords

Coronary flow reserve,molecular imaging,myocardial perfusion imaging,myocardial viability,PET/CTA hybrid imaging

Source

Kevin Chen, MD,1 Edward J. Miller, MD PhD,1 and Mehran M. Sadeghi, MD1,2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6426655/