Using optical coherence tomography (OCT)-to guide percutaneous coronary intervention (PCI) is associated with a lower occurrence of major adverse cardiac events (MACE) or significant angina in patients with angiographically-intermediate coronary lesions (AICL) than fractional flow reserve (FFR)-guidance. However, FFR guided PCI is associated with a higher rate of medical management and lower costs.
Co-principal investigator Francesco Burzotta (Fondazione Policlinico Universitario A Gemelli IRCCS, and Università Cattolica del Sacro Cuore, Rome, Italy) presented the findings from the FORZA study at a late-breaking trials session at the Transcatheter Therapeutics Scientific Symposium (TCT 2019; 24–29 September, San Francisco, USA). The data were also simultaneously published in JACC: Cardiovascular Interventions.
Burzotta described the decision about whether to treat or conservatively manage patients with angiographically intermediate coronary lesions as “a major clinical issue in our daily practice”.
“A large body of evidence suggests that a functional evaluation using FFR is able to accurately identify lesions to be treated. Data regarding the possible value of OCT in the selection of lesions to be treated are lacking. When treating a lesion, the value of OCT to optimise the PCI result is increasingly established, while data for FFR are scarce.”
FORZA (Fractional flow reserve versus optical coherence tomography to guide revascularisation of intermediate coronary stenosis) was a single centre, investigator driven, non-sponsored, prospective, randomised trial that aimed to compare the clinical and economic impact of OCT-guidance and FFR-guidance in the management of patients with angiographically intermediate coronary lesions.
Patients with ≥one lesion were randomised 1:1 to FFR or OCT guidance. In the FFR arm, the cutoff for intervention with PCI was FFR ≤0.8, and it aimed to achieve a post-PCI FFR of ≥0.9. If FFR was >0.8, patients received optimal medical therapy. In the OCT arm, PCI was performed if the area of stenosis was ≥75%, or if it was between 50% and 75% with either a minimal lumen area <2.5 mm2 or plaque rupture. PCI aimed at minimising major stent malapposition, major stent underexpansion, or major edge dissection. Patients who did not undergo OCT-guided PCI received optimal medical therapy.
Angina was evaluated using the Seattle Angina Questionnaire (SAQ), and major adverse cardiac events (MACE) and cost were assessed. The predefined primary combined endpoint was MACE or significant angina (defined as SAQ frequency scale <90) at 13-months. Secondary endpoints were cost per patient, rate of medically managed patients, MACE, and target vessel failure at 13 months. The hypothesis of the study was that OCT was superior to FFR, and sample size was calculated on the basis that OCT could reduce the occurrence of the primary endpoint by 50%.
Patients baseline characteristics showed no major differences between the two randomised groups, Burzotta told delegates, underlining that “there was a significantly higher rate of patients initially managed by optimal medical therapy with FFR; there was a higher use of contrast [media], stents, and balloons with OCT, and a lower rate of acute kidney injury with FFR, and no patient had haemodialysis.”
In all, 350 patients with 446 angiographically intermediate coronary lesions were enrolled (176 randomised to FFR and 174 to OCT). The primary endpoint of MACE or significant angina at 13-months occurred in 14.8% patients in the FFR arm, and in 8% of the OCT arm (p=0.048). This result was driven by a lower occurrence of all primary endpoint components that was not statistically significant: all-cause death FFR 1.7% vs. OCT 1.1% (p=0.66); non-fatal myocardial infarction 2.8% vs 0.6%, respectively (p=0.098); target vessel revarscularisation 4.5% for FFR vs 2.3% for OCT (p=0.247); and significant angina (SAQ <90) 6.7 FFR vs. 4.8 OCT (p=0.495).
The total cost was significantly lower (p<0.001) with FFR: estimated mean cost per patient was €2,578 for FFR vs €3,750 for OCT (p<0.001); rates of medically managed patients were significantly higher (p<0.001) with FFR (62.5%) in comparison to OCT (44.8%). Rates of target vessel failure were 7.4% for FFR vs 2.3% for OCT (p=0.027).
At TCT 2019, Burzotta concluded: “In patients with intermediate coronary lesions suitable for invasive evaluation by both OCT or FFR, the selection of OCT is safe, causes an initially higher number of PCIs, but is associated with lower occurrence of the combined endpoint of MACE or significant angina after 13 months. However, the selection of FFR is associated with a higher rate of medically managed patients and lower costs up to 13 months.”
Writing in JACC Cardiovascular Interventions, Burzotta, Antonio Maria Leone (Fondazione Policlinico Universitario A Gemelli IRCCS, Rome, Italy) et al outlined the limitations, which included the small sample size and that the primary composite endpoint of comprised occurrence of angina represents a weak endpoint. In addition, they say, patients and physicians were not blinded, “and this (especially in the presence of untreated lesions) may determine management biases, especially for target vessel revascularisation and medical treatment. In particular, the significantly lower rate of dual antiplatelet therapy and the trend to lower rate of statin therapy in the FFR arm may have led to a significant disadvantage with respect to medical therapy.”
Consequently, they say, the results observed do not allow any firm conclusions to be drawn, and Burzotta, Leone and colleagues call for further evaluations of the implications associated with the different management strategies of patients with angiographically intermediate coronary lesions.