Correspondence Response to Letter Regarding Article, “Primary Coronary Microvascular Dysfunction: Clinical

We thank Dr Fearon for his interest in our review article on primary microvascular angina (MVA). We agree with him that invasive methods would provide more complete information about presence and characteristics of coronary microvascular dysfunction in patients with chest pain and normal coronary arteries. However, although small, the risk of serious adverse events with invasive tests cannot be regarded as absent,1,2 and it may raise particular concerns when considering the excellent outcome of patients with MVA3 and the lack of any evidence that invasive assessment of coronary microvascular dysfunction may predict major cardiac events (eg, cardiac death or acute myocardial infarc-tion) in these patients.2,4 Moreover, a reliable assessment of coronary microvascular dys-function can now be obtained noninvasively, an approach that, besides being safer, is also cheaper than invasive methods, which i