Classical and endogen type of coronary microvascular dysfunction and potential association with cardiovascular events...

Background To investigate a potential association of Positron Emission Tomography (PET)-determined classical and endogen type of coronary microvascular dysfunction (CMD) and cardiovascular outcome in cardio-metabolic disease.Methods We consecutively enrolled 287 symptomatic patients with normal pharmacological stress and rest myocardial perfusion on ¹³N-ammonia PET/CT. ¹³N-ammonia PET/CT concurrently assessed myocardial flow reserve (MFR). normal coronary microvascular function (nCMF) was defined by a MFR of ≥ 2.0, while an abnormal MFR of < 2.0 signified CMD. Patients were then sub-grouped nCMF with classical type (group 1) or endogen type (group 2) and CMD with classical type (group 3) and endogen type (group 4), respectively. Major adverse cardiovascular events (cardiovascular death, acute coronary syndrome, myocardial infarction, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, or ischemic stroke) were assessed as clinical outcome parameters over a mean follow-up of 2.52 ± 1.31years.Results During follow-up, 15 of 287 patients (5%) suffered cardiovascular events. Six of the group 1 patients developed a cerebral stroke. In group 2, 3, and 4, cardiovascular events occurred in 0, 8 (four cardiovascular death, three coronary angioplasty), and 1 (one ischemic) patient, respectively (p ≤ 0.0001, univariate by log-rank test). Patients in group 3 demonstrated a significantly higher incidence of cardiovascular events compared to group 1, 2 and 4, respectively (p = 0.004, log-rank test). On multivariate analysis, only diabetes mellitus remained independently associated with cardiovascular events (p < 0.0001, multivariate by Cox regression model).Conclusions The classical but not necessarily the endogen type of CMD is potentially associated with an increased risk of developing cardiovascular events in a cardiometabolic disease population. Graphical abstract.