FRACTIONAL FLOW RESERVE (FFR) AT 2014- WHERE ARE WE AND WHERE IS IT GOING
Edo Kaluski, M.D., University Hospital, Newark, NJ, USA
New society guidelines support now the use of FFR over to assess intermediate stable native coronary lesions (now defined as 50-90% diameter stenosis when stress imaging is contraindicated, non-diagnostic, discordant or unavailable. In subjects with stable coronary artery disease (CAD) percutaneous coronary intervention (PCI) of lesions with FFR <080 improves symptom control and hospitalization for urgent revascularization however the predictive value for clinical events remains low (˜20% in 2 years).
There is limited data regarding the role of FFR in guiding therapy acute coronary syndromes, left main disease, vein grafts and mammary lesions, peri-procedural PCI results, sidebranch intervention in bifurcation lesion stenting or non-coronary interventions.
In the past 5 years sub-optimal vasodilatation was observed with intracoronary or intravenous adenosine and new agents (regadenoson and nitroprusside) as well as instantaneous wave free ratio (iFR) were trialed. While newer agents are effective and safe iFR did not seem to yield similar resistance (2.5 fold higher) or results as FFR (iFR was 9% higher with precision limits of ±17%). Attempts to produce non-invasive CT angiography (CTA) based FFR map are encouraging but are still lacking the precision of FFR.
In the next 5 years we are hoping that the role of iFR and non-invasive CTA based FFR will be further clarified. The role of FFR in additional patient and lesion subsets should be refined in coronaries as well as other vascular beds. Algorithms and tools to determine the relative contribution of multiple sequential or parallel lesions may further facilitate the use of FFR in multi-vessel disease.