Deferring revascularization based on either fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) is equally safe, according to a pooled patient-level analysis presented Friday at the PCR e-Course.
Javier Escaned MD, PhD, of Hospital Clínico San Carlos, Madrid, Spain, presented the results on behalf of the investigators.
In the light of the ISCHEMIA trial, which showed no difference between optimal medical therapy alone and revascularization plus medical therapy in patients with stable ischemic heart disease, revascularization deferral with medical treatment has become an important strategy. The investigators pooled the results of the iFR: DEFINE FLAIR (n=2,467 patients) and iFR SWEDEHEART (n=2,019) randomized clinical trials to examine two key questions: 1) to investigate whether 2-year outcomes of deferred revascularization are similar when the decision is based on FFR or iFR, and 2) to investigate the relationship between patient age, deferral of revascularization based on FFR and iFR, and clinical outcomes
The study showed that iFR resulted in more patients having revascularization deferred (iFR 50% vs. FFR 45%, p<0.01). However, the risk of death, non-fatal myocardial infarction (MI) and unplanned revascularization over 2 years was no different in the FFR or iFR group (iFR 7.43% vs. FFR 7.4%, p=0.94). Individual components of death, non-fatal MI and unplanned revascularization were also comparable between the groups.
The study also demonstrated that FFR lead to more revascularization procedures, particularly in patients younger than 60 years of age; these younger patients had 12% more revascularization when FFR was used.
“Our study demonstrates similar safety of iFR and FFR in deferring revascularization in the midterm and reveals a strong interaction of age with FFR-based deferral, potentially related to a varying age-related hyperemic response to adenosine, that merits further investigation,” Escaned said in a press release announcing the results.
The DEFINE FLAIR and IFR SWEDEHEART studies were funded through unrestricted grants from Philips-Volcano.
PCR e-Course is the virtual meeting being held in place of the annual in-person EuroPCR congress, which was canceled because of the COVID-19 pandemic.