Fractional Flow Reserve or Intravascular Ultrasonography to Guide PCI (2-year follow-up results)

Reviewer: Dr Neşet Ali Savaş

Presentation:EUROPCR 2023

Background

In the multinational randomized trial of FLAVOR (NCT02673424), FFR guidance was not inferior to IVUS guidance in terms of 2-year clinical outcomes. µQFR based on Murray's law is a new method for rapid calculation of FFR from a single angiographic view. In the study; It was aimed to investigate the prognostic value of µQFR after PCI in predicting 2-year clinical outcomes in the FLAVOR population. The prognostic value of combined post-PCI µQFR and stent parameters in the IVUS-guided group was also investigated.

Method

In the FLAVOR study, a total of 831 vessels were treated in 801 patients with at least 1 PCI-treated vessel. 25 patients were excluded due to poor image quality. In the study, 806 vessels were examined in 777 patients with µQFR after PCI. 293 vessels in 283 patients in the FFR-guided group; In the IVUS-guided group, 494 patients and 513 vessels were examined. The stent, which was applied to 459 vessels in a total of 441 patients, was examined. Fifty-four patients with no or insufficient IVUS image after PCI were excluded. The 2-year target vessel failure was evaluated as a combination of cardiac death, target vessel MI, and TVR. µQFR and IVUS were analyzed in an academic core laboratory unaware of clinical data.

Results

In the study; The mean age of the patients was 65, 26% were female, and 59% had multi-vessel disease. The clinical presentation of 56% was stable angina. The mean pre-PCI Syntax score was 9. 63% of the patients had LAD, and 24% had RCA disease. An average of 1.2 stents with an average length of 28 mm and a diameter of 3 mm were used in the study. The optimal PCI ratio was 58%. In 2-year events classified according to µQFR after PCI; Patients with a Post PCI QFR ratio of 0.95-1 had significantly less TVF, TVR, TVMI. In the IVUS group, the stent length was 30.5 ± 13.8 mm, the MSA was 6.64 ± 2.19 mm2, the Post-PCI Max plaque load was 63.2 ± 7.6%, and the mean plaque load was 42.6 ± 7.1.

Interpretation

In patients randomized from the FLAVOR study to IVUS or FFR-guided PCI, post-PCI µQFR < 0.90 was associated with a higher 2-year TVF rate (6.1% vs. 2.7%, p = 0.028). For IVUS-guided PCI, the combined physiology and imaging estimate was 2 years TVF (25.0 vs 2.7%, p< 0.0001). In addition, stent overexpansion (5>mm) has been associated with worse clinical outcomes.