Impact of intravascular ultrasound findings in patients with a post PCI fractional flow reserve ≤0.85 on 2 year clinical outcome

Background: Patients with a low post PCI fractional flow reserve (FFR) are at increased risk for future adverse cardiac events. The aim of the present study was to assess the impact of specific intravascular ultrasound (IVUS) findings in patients with a low post percutaneous coronary intervention (PCI) FFR on long-term clinical outcome.

Methods: In a subgroup analysis, 100 vessels with an FFR value ≤0.85 underwent post PCI IVUS to further assess the potential determinants for low post PCI FFR. No further action was taken to improve post PCI FFR. The primary endpoint of this study was the event free survival of target vessel failure (TVF) at two years in patients with a post PCI FFR ≤0.85, which was defined as a composite of cardiac death, target vessel myocardial infarction or target vessel revascularization.

Results: In patients with a post PCI FFR ≤0.85, TVF free survival rates were 88.5% vs. 95.5% for patients with versus without residual proximal lesions and 88.2% vs. 95.5% for patients with versus without residual distal lesions respectively (HR = 2.53, 95% confidence interval (CI) 0.52-12.25, p = .25 and HR = 2.60, 95% CI 0.54-12.59, p = .24 respectively). TVF free survival was 92.8% vs. 93.5% in patients with versus without stent underexpansion >20% (HR = 1.01, 95% CI 0.21-4.88, p = .99) and 89.3% vs. 97.8% in patients with versus without any residual focal lesion including lumen compromising hematoma (HR = 4.64, 95% CI 0.55-39.22, p = .18).

Conclusion: Numerically higher TVF rates were observed in patients with a post PCI FFR ≤0.85 and clear focal residual disease as assessed with IVUS.