Coronary disease & ACSDiagnostic or prognostic study

Core Laboratory Comparison of Angiography-Derived Indexes of Microvascular Resistance vs Pressure-Wire IMR and Absolute Resistance

JACC Cardiovasc IntervPublished

  • Diagnostic accuracy study
  • core laboratory
  • blinded

Authors' conclusion

All 5 angio-IMR methods demonstrated poor diagnostic accuracy compared with PW-IMR and Rmicro, highlighting significant limitations in their clinical utility.

Study context

Population
Patients with angina and nonobstructive coronary arteries assessed for coronary microvascular dysfunction274 and 109 vessels
Comparison
Angio-IMR vs PW-IMR and Rmicro
  • PW-IMRn = 270reference
  • Rmicron = 42reference
Outcome
Per-vessel diagnostic performance of angio-IMR vs PW-IMR ≥25 and Rmicro ≥475 WU (ROC, Bland-Altman, confusion matrices)

Performance

As reported in the abstract

Diagnostic performance of angio-IMR
Test or modelAUC for PW-IMR ≥25 (all methods)Accuracy, method E, PW-IMR ≥25 (angio-IMR ≥25 threshold)Accuracy, method E, Rmicro ≥475 Wood units (WU) (angio-IMR ≥25 threshold)
Angio-IMR0.530 to 0.57661.4%62.0%
AUC for PW-IMR ≥25 not significant for any method
P > 0.05
3 of 5 methods overestimated PW-IMR (mean bias), all with large random errors
−20.72 to −26.36

Further findings

OutcomeAngio-IMRPW-IMRRmicro
Reference index valuesmedian 19.02 (IQR 12.79–28.08)median 387.50 (IQR 312.00–501.00) WU
PW-IMR ≥25Not reported in the abstract81 of 274 vessels (29.6%)Not reported in the abstract
Rmicro ≥475 WUNot reported in the abstractNot reported in the abstract33 of 109 vessels (30.3%)

Original publication

Core Laboratory Comparison of Angiography-Derived Indexes of Microvascular Resistance vs Pressure-Wire IMR and Absolute Resistance. JACC Cardiovasc Interv. Published 25 October 2025. doi:10.1016/j.jcin.2025.10.027

Summarised from the published abstract; every number is checked against it