Table 1

Mixed Pathophysiologies of Microvascular Angina and Function in 5,900 PETs

Criteria for Microvascular Angina
CFR ≤2.2CFR ≤2.2CFR >2.2High CFC§
Cases21 (0.4)83 (1.4)167 (2.8)174 (3)
Average maximum pixel CFR2.27 ± 0.52.48 ± 0.53.91 ± 1.13.74 ± 1.2
Microvascular functionImpairedImpairedGoodGood
Rel str per <0.7 for >10% LV9/21 (43)45/84 (54)53/167 (32)43/174 (25)
Female62393548
Risk factors or coronary CaYesYesYesYes
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/yr1%/yr0.8%/yr0.6%/yr0.4%/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.