Prognostic impact and clinical outcomes of coronary flow reserve and hyperaemic microvascular resistance

EuroIntervention. 2021 Sep 20;17(7):569-575. doi: 10.4244/EIJ-D-20-00853.

Abstract

Background: Most studies dichotomise indices of coronary microvascular function to assess their prognostic values.

Aims: We aimed to investigate whether coronary flow reserve (CFR) and hyperaemic microvascular resistance (HMR) as continua predict major adverse cardiovascular events (MACE), comprising all-cause death, myocardial infarction, revascularisation, and stroke in patients with ischaemia and non-obstructive coronary artery disease.

Methods: A total of 610 patients were included and followed up over a median of 8.0 years (199 individual MACE in 174 patients).

Results: Both CFR and HMR as continua predicted MACE with an odds ratio (OR) of 0.70 (per 1-unit increase, 95% confidence interval [CI]: 0.53, 0.92; p=0.01) and 1.63 (per 1 mmHg/cm/s, 95% CI: 1.20, 2.21; p=0.002), respectively. This relationship remained significant after adjustment for age and sex with an adjusted OR of 0.66 (per 1 unit increase, 95% CI: 0.49, 0.89; p=0.01) and 1.42 (per 1 mmHg/cm/s, 95% CI: 1.03, 1.94; p=0.03). HMR added prognostic value to CFR in predicting MACE (net reclassification index 0.17, 95% CI: 0.02, 0.31; p=0.03; integrated discrimination improvement 0.01, 95% CI: 0.0001, 0.02; p=0.046).

Conclusions: Both CFR and HMR as continuous variables predict future risk of MACE.

MeSH terms

  • Coronary Artery Disease* / diagnostic imaging
  • Fractional Flow Reserve, Myocardial*
  • Humans
  • Hyperemia*
  • Predictive Value of Tests
  • Prognosis
  • Risk Factors