Coronary interventions

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

EuroIntervention 2021;17:569-575. DOI: 10.4244/EIJ-D-20-00853

Takumi Toya
Takumi Toya1,2, MD; Michel T. Corban1, MD; Ji Young Park1, MD, PhD; Ali Ahmad1, MD; Ilke Ӧzcan1, MD; Faten Sebaali1; Jaskanwal D.S. Sara1, MBChB; Rajiv Gulati1, MD, PhD; Lilach O. Lerman3, MD, PhD; Amir Lerman1, MD
1. Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA; 2. Division of Cardiology, National Defense Medical College, Tokorozawa, Saitama, Japan; 3. Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA

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.

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clinical researchother techniquerisk stratification
Coronary interventionsOther coronary interventions
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