The prognostic value of combined intracoronary pressure and blood flow velocity measurements after deferral of percutaneous coronary intervention.

OBJECTIVES

We evaluated deferral of PCI of intermediate coronary lesions (IL) using fractional (FFR) and coronary flow reserve (CFR) hyperemic stenosis resistance index (HSR) in patients with a negative or nondiagnostic and noninvasive stress tests.

BACKGROUND

Outcome after deferral of PCI of IL with discordant results between FFR and CFR is unknown.

METHODS

PCI was deferred in 186 IL (mean diameter stenosis: 52%). Patients were divided according to the results of FFR and CFR in group A; FFR >or= 0.75 and CFR >or= 2.0 (n = 129), group B; FFR >or= 0.75 and CFR 2.0 (n = 28), group C; FFR 0.75 and CFR >or= 2.0 (n = 23) and group D; FFR 0.75 and CFR 2.0 (n = 6). Patients were followed for one year to document major adverse cardiac events (MACE).

RESULTS

Nineteen MACEs (0 deaths, 4 myocardial infarctions, 1 CABG, and 14 PCIs) occurred during a follow up of 323 +/- 88 days. MACE rate was lowest (4.7%) when FFR, CFR, and HSR were normal. A higher MACE rate was observed when concordant abnormal (group D) or discordant results between FFR and CFR (group B and C) were compared to concordant normal values (group A, 33.3% vs. 19.7% vs. 5.4%, P = 0.008). Multivariate regression analysis showed a higher predictive power for HSR than for FFR and CFR.

CONCLUSIONS

Abnormal FFR or abnormal CFR was documented in 31% of intermediate coronary lesions. Deferral of PCI in this group was associated with a high MACE rate, which underscores the rationale of combined pressure and flow measurements providing a stenosis resistance index that is better suited for clinical decision making in these lesions.