Author + information
- Lorenzo Azzalini1,
- Luciano Candilio2,
- Enrico Poletti2,
- Alaide Chieffo3,
- Francesco Giannini3,
- Antonio Colombo4 and
- Azeem Latib3
- 1Interventional Cardiology Unit, San Raffaele Scientific Institute, Milan, Milan, Italy
- 2San Raffaele Hospital, Milan, Milan, Italy
- 3Interventional Cardiology Institute San Raffaele Hospital, Milan, Milan, Italy
- 4Interventional Cardiology Institute San Raffaele Hospital - Stamford Hospital - Columbia University - Centro Cuore Columbus, Milan, Milan, Italy
The role of fractional flow reserve (FFR) evaluation after percutaneous coronary intervention (PCI) has received little scrutiny. We aimed to evaluate the impact of post-PCI FFR in a prospective study.
Single-center prospective registry of patients (n=65) undergoing PCI for stable coronary artery disease (CAD) or non-ST-elevation acute coronary syndrome (ACS). Baseline and post-PCI FFR were measured with the Acist Navvus Rapid Exchange FFR Microcatheter (ACIST Medical Systems, Eden Prairie, MN). Patients were divided according to the post-PCI FFR value (<0.90 vs. ≥0.90). The primary endpoint was the proportion of cases in which an action was undertaken in light of a post-PCI FFR value <0.90. The secondary endpoints were clinical outcomes at 30 days and 1 year. Target-vessel failure (TVF) was defined as a composite of cardiac death, target-vessel myocardial infarction, and ischemia-driven target-vessel revascularization.
Overall mean age was 68.9±6.3, 32% were diabetics. Ejection fraction was 51.8±10.0%. The majority of procedures were indicated for stable CAD (66%). SYNTAX score was 13.9±7.9. There were no differences in baseline clinical and angiographic characteristics between patients with post-PCI FFR <0.90 (n=43) and those with post-PCI FFR ≥0.90 (n=22), with the exception of a higher prevalence of left anterior descending as target vessel in post-PCI FFR <0.90 (84% vs. 59%, p=0.03). Baseline FFR was 0.72±0.08 in post-PCI FFR <0.90 vs. 0.69±0.14 in post-PCI FFR ≥0.90 (p=0.40). Overall, 86% received a drug-eluting stent, 6% a bioresorbable scaffold, and 8% a drug-eluting balloon (DEB) (p=0.25). Total stent length was 37.9±25.4 mm (1.5±1.0 implanted stents), with no difference between groups. Post-PCI FFR was 0.82±0.05 in post-PCI FFR <0.90 vs. 0.94±0.02 in post-PCI FFR ≥0.90 (p<0.001). The reasons for an FFR <0.90 were: residual distal disease not amenable to treatment (42%), residual uncovered distal (2%) and proximal plaques (14%), stent underexpansion (2%), edge dissection (2%), unknown (37%). An action was undertaken in 15/43 (35%) of patients with a post-PCI FFR <0.90: invasive imaging 19%, further stenting 26%, further post-dilatation 28%, treatment of distal vessel with a DEB 2%. In only 3/15 patients (20%) that had an FFR <0.90 after PCI, additional interventions (stenting of residual uncovered proximal plaques in all three) achieved an increase of the FFR value to ≥0.90. A statistically significant (p=0.02), albeit of little clinical relevance (0.02±0.05), increase in FFR value was observed in patients who had a post-PCI FFR <0.90. Final FFR was 0.83±0.05 in post-PCI FFR <0.90 vs. 0.94±0.02 in post-PCI FFR ≥0.90 (p<0.001). At 30 days, no TVF events were recorded. However, one patient with a final FFR <0.90 (2.6%) was admitted for chest pain (p=0.43). There was no difference in angina class between the two groups. One year follow-up is in progress.
Two thirds of patients present a post-PCI FFR <0.90. This is due to a variety of reasons, often not amenable to percutaneous treatment or of unclear etiology. Further interventions (performed in about one third of cases) do not appear to have a substantial impact on final FFR. Further larger studies should assess the clinical impact of our findings.
IMAGING: FFR and Physiologic Lesion Assessment