FFR-SEARCH Study Investigates Relationship of Post-PCI FFR and 30-Day Outcomes
May 1, 2019–Findings on routine fractional flow reserve (FFR) measurement after percutaneous coronary intervention (PCI) in the FFR-SEARCH study were published by Rutger J. van Bommel, MD, et al in Circulation: Cardiovascular Interventions.
FFR-SEARCH is a prospective registry in which FFR measurements were performed after PCI in 1,000 consecutive patients. The investigators sought to evaluate post-PCI FFR values, identify predictors for a low post-PCI FFR, and investigate whether there is a relationship between postprocedural FFR and outcome during 30-day follow-up.
In the study, the clinical endpoint was defined as a composite of death, target vessel revascularization, or nonfatal myocardial infarction at 30-day follow-up. All FFR measurements were performed under maximum hyperemia with intravenous adenosine using the Navvus RXi system (Acist Medical Systems, Inc.).
As summarized in Circulation: Cardiovascular Interventions, measurement of post-PCI FFR was successful in 959 patients (96%). A total of 1,165 lesions were assessed. There were no complications related to the microcatheter. A total of 322 patients with ST-segment elevation myocardial infarction with 371 measured lesions were excluded, leaving 637 patients with 794 measured lesions for the final analysis.
The investigators found that overall post-PCI FFR was 0.90 ± 0.07. In 396 lesions (50%), post-PCI FFR was > 0.90. A total of 357 patients (56%) had one or more lesions with a post-PCI FFR ≤ 0.90, and 73 patients (11%) had one or more lesions with a post-PCI FFR ≤ 0.80 with post-PCI FFR ≤ 0.80 in 78 lesions (9.8%).
The investigators noted that complex lesion characteristics, use of multiple stents, and smaller reference vessel diameter were associated with post-PCI FFR ≤ 0.90. During follow-up, 11 patients (1.8%) reached the clinical endpoint. There was no significant relationship between post-PCI FFR and the clinical endpoint at 30-day follow-up (P = .636).
In Circulation: Cardiovascular Interventions, the investigators concluded that routine measurement of post-PCI FFR using a monorail microcatheter is safe and feasible. Additionally, they reported that several lesion and patient characteristics were associated with a low post-PCI FFR and that post-PCI FFR did not correlate with clinical events at 30 days.