Coronary disease & ACSCohort study

Multicenter Evaluation of Myocardial Flow Reserve as a Prognostic Marker for Mortality in 13 N-Ammonia Positron Emission Tomography (PET) Myocardial Perfusion Imaging

Circ Cardiovasc ImagingPublished

  • Multicenter registry cohort
  • 5 sites
  • REFINE PET registry

Authors' conclusion

In this large multicenter cohort, MFR derived from 13 N-ammonia PET myocardial perfusion imaging is a strong, independent predictor of all-cause mortality, even in patients with normal perfusion. An MFR of ≤2 identifies elevated risk, while higher values are associated with improved survival. These findings support the routine integration of MFR to enhance risk stratification in patients with suspected or known coronary artery disease.

Study context

Population
Patients with suspected or known coronary artery disease who underwent 13 N-ammonia PET myocardial perfusion imagingpatients included, median follow-up 3.8 years
Participants
6,277 patients
Exposure
Patients with myocardial flow reserve (MFR) ≤2 vs those with MFR >2
  • MFR ≤2n = 1,895
  • MFR >2n = 4,382reference
Outcome
All-cause mortality
Follow-up
Median 3.8 years

Main finding

As reported in the abstract

Hazard ratio

2.70

95% CI 2.41–3.03

P < 0.001

Events by group

MFR ≤2 vs MFR >2
hazard ratio 2.70 (95% CI 2.41–3.03); P < 0.001

Observational data: associations, not effects.

Further findings

Outcomehazard ratio (95% CI)P value
All-cause mortality among patients with no perfusion defects (subgroup) · multivariable2.36 (1.93–2.89)P < 0.001

Annualized all-cause mortality rates by MFR and summed stress score

Range
1.7 to 15.8

Mortality risk across increasing MFR deciles

Hazard ratio range, decreasing across increasing deciles
2.73 (95% CI, 2.39-3.11) to 0.35 (95% CI, 0.25-0.49)

Original publication

Multicenter Evaluation of Myocardial Flow Reserve as a Prognostic Marker for Mortality in 13 N-Ammonia PET Myocardial Perfusion Imaging. Circ Cardiovasc Imaging. Published 30 January 2026. doi:10.1161/circimaging.125.018729

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