Coronary microvascular disease: coronary flow reserve and the complementary role of positron emission tomography and angiography.

We present the case of a woman in her 30s with chronic residual chest pain accompanied by dyspnoea on exertion despite multiple evaluations and cardiac testing over a period of nearly 14 years. Ultimately, she underwent N-13 Ammonia positron emission tomography (PET) myocardial perfusion imaging, which demonstrated mild three-vessel microvascular disease. Coronary microvascular disease (CMD) plays a major role in determining myocardial ischaemia in many cardiovascular conditions. The diagnosis relies on indirect measurement of coronary flow reserve (CFR), which may be evaluated both invasively and non-invasively. Assessing CFR not only allows for successful diagnosis of CMD but holds powerful prognostic value for cardiovascular mortality. PET myocardial perfusion imaging is a complementary tool to coronary angiography to achieve diagnosis in a non-invasive, highly accurate and reproducible manner.