|Criteria for Microvascular Angina∗|
|CFR ≤2.2∗||CFR ≤2.2†||CFR >2.2‡||High CFC§|
|Cases||21 (0.4)||83 (1.4)||167 (2.8)||174 (3)|
|Average maximum pixel CFR||2.27 ± 0.5||2.48 ± 0.5||3.91 ± 1.1||3.74 ± 1.2|
|Rel str per <0.7 for >10% LV‖||9/21 (43)||45/84 (54)||53/167 (32)||43/174 (25)|
|Risk factors or coronary Ca¶||Yes||Yes||Yes||Yes|
|MI or death over 9 yrs#||2/21 (9.5)||8/83 (9.6)||9/167 (5.4)||6/174 (3.5)|
|Approximate MI or death/yr||1%/yr||0.8%/yr||0.6%/yr||0.4%/yr|
Values are n (%), mean ± SD, n/N (%), or %, unless otherwise indicated.
CAD = coronary artery disease; CFC = coronary flow capacity; CFR = coronary flow reserve; LV = left ventricular; MESA = Multi-Ethnic Study of Atherosclerosis; MI = myocardial infarction; PET = positron emission tomography.
↵∗ Angina, no known CAD, global CFR ≤2.2, and no stress-induced relative defects defined as rest-to-stress change of >5% of LV with ≤60% of maximum activity.
↵† Angina, known CAD by angiogram, procedures, or events, but no stress-induced relative defects as defined in the preceding text.
↵‡ Angina, global CFR >2.2, no stress induced relative defects as defined in the preceding text, includes no known CAD and known CAD by angiogram, procedures, or events, but no stress-induced relative defects as defined in the preceding text.
↵§ Angina, high CFC >70% of the LV normal or minimally reduced CFC (CFR >2.4 and stress >1.8 ml/min/g).
↵‖ Fractional flow reserve as relative absolute stress perfusion PET reflecting low subendocardial perfusion. Rel str per = relative distribution of stress in ml/min/g expressed as a fraction of the maximum.
↵¶ MESA risk score >7%.
↵# Median follow-up 3.2 years.