FFR Guidance Could Reduce Need for Multivessel Primary PCI

A large proportion of lesions in noninfarct arteries with visual stenosis estimates above 50% are not flow limiting when fractional flow reserve (FFR) is measured, according to early study results presented at TCT 2015.

For the ongoing COMPARE ACUTE trial, Pieter C. Smits, MD, PhD, of Maasstad Hospital, Rotterdam, the Netherlands, and colleagues enrolled 728 STEMI patients with multivessel disease who were undergoing primary PCI at 22 sites in Europe and Asia between July 2011 and April 2015. Patients were randomized to undergo either multivessel PCI with FFR guidance or culprit vessel-only PCI with masked FFR measurements of noninfarct lesions. Mean age in the current analysis is 62 years, and men comprise 77.1% of the cohort.

FFR values were measured directly after primary PCI and only in lesions with visual estimate of at least 50% stenosis on angiography. Primary PCI was performed in the left ventricular descending artery (LAD) in 37.3% of patients, in the right coronary artery (RCA) in 44.0% and in the circumflex artery (RCX) in 18.7%. Procedural success—defined as TIMI flow grade 3—was achieved in 95.8%.

FFR measurements in 1,000 noninfarct-related vessels (1,023 lesions) were assessed in the LAD (40.1%), RCA (25.8%) and RCX (34.1%). In all, 40% of the lesions were FFR positive (≤ 0.80 under maximal hyperemia), 54% were FFR negative and 6% had no available data. More than half of patients (57%) had no hemodynamically significant lesions in noninfarct-related arteries.

Functional assessment provides new insight

Although current guidelines recommend PCI of noninfarct-related arteries at the time of primary PCI, the abstract notes, recent studies have challenged that practice. Those studies, however, have graded stenosis by visual estimate of angiography, and the COMPARE ACUTE trial used FFR assessment to further elucidate this issue.

“A large proportion of [nonculprit lesions that appear severe on angiography] are not flow limiting and potentially do not need treatment or further investigation when FFR is done in the acute phase,” Smits told TCT Daily. This is not particularly surprising, he added, as a similar finding was observed in the FAME trial. Moreover, it also corresponds to experience in daily practice.

The clinical relevance of COMPARE ACUTE’s findings will not be fully clear until the primary endpoint of MACCE, defined as death, MI, any revascularization or cerebral accident at 12 months is reported, Smits said, adding that study enrollment is expected to end in November 2015.

Disclosures:

• Smits has received speaking and/or consultant fees from Abbott Vascular, St. Jude Medical and Terumo.