Characterization of real-world patients with low fractional flow reserve immediately after drug-eluting stents implantation

Angiographic Findings and Post-Percutaneous Coronary Intervention Fractional Flow Reserve

Importance

The associations between angiographic findings and post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and their clinical relevance according to residual functional disease burden have not been thoroughly investigated.

Objectives

To evaluate the association of angiographic and physiologic parameters according to residual functional disease burden after drug-eluting stent implantation.

Design, Setting, and Participants

This cohort study population was from the International Post-PCI FFR registry, which incorporated 4 registries from Korea, China, and Japan. Patients who underwent angiographically successful second-generation drug-eluting stent implantation and post-PCI FFR measurement were included in the analysis. The patients were divided into 3 groups according to the residual disease burden (post-PCI FFR ≤0.80 [residual ischemia], 0.81-0.86 [suboptimal], and >0.86 [optimal]). The data were collected from August 23, 2018, to June 11, 2019, and the current analysis was performed from January 11, 2022, to October 7, 2023.

Exposures

Angiographic parameters and post-PCI FFR.

Main Outcomes and Measures

The primary outcome was target vessel failure (TVF), defined as a composite of cardiac death, target vessel-related myocardial infarction, and target vessel revascularization (TVR) at 2 years.

Results

In this cohort of 2147 patients, the mean (SD) age was 64.3 (10.0) years, and 1644 patients (76.6%) were men. Based on the post-PCI physiologic status, 269 patients (12.5%) had residual ischemia, 551 (25.7%) had suboptimal results, and 1327 (61.8%) had optimal results. Angiographic parameters had poor correlations with post-PCI FFR (r < 0.20). Post-PCI FFR was isolated from all angiographic parameters in the unsupervised hierarchical cluster analysis. Post-PCI FFR was associated with the occurrence of TVF (adjusted hazard ratio [AHR] per post-PCI FFR 0.01 increase, 0.94 [95% CI, 0.92-0.97]; P < .001), but angiographic parameters were not. The residual ischemia group had a significantly higher rate of TVF than the suboptimal group (AHR, 1.75 [95% CI, 1.08-2.83]; P = .02) and the optimal group (AHR, 2.94 [95% CI, 1.82-4.73]; P < .001). The TVR in the residual ischemia group was predominantly associated with TVR in the nonstented segment (14 [53.8%]), unlike the other 2 groups (3 [10.0%] in the suboptimal group and 13 [30.2%] in the optimal group).

Conclusions and Relevance

In this cohort study of the International Post-PCI FFR registry, a low degree of associations were observed between angiographic and physiologic parameters after PCI. Post-PCI FFR, unlike angiographic parameters, was associated with clinical events and the distribution of clinical events. The current study supports the use of post-PCI FFR as a procedural quality metric and further prospective study is warranted.

Intravascular Ultrasound vs. Fractional Flow Reserve for Percutaneous Coronary Intervention Optimization in Long Coronary Artery Lesions

BACKGROUND

intravascular ultrasound (IVUS) and fractional flow reserve (FFR) have both been shown to be superior to angiography in optimizing percutaneous coronary intervention (PCI). However, there is still a lack of comparative studies between PCI optimization using physiology and intravascular imaging head-to-head. The aim of this study was to compare the effectiveness of FFR and IVUS PCI optimization strategies on the functional PCI result (assessed with FFR) immediately post-PCI and at 9-12 months after the treatment of long coronary lesions.

METHODS

This was a single-center study comparing post-PCI FFR between two different PCI optimization strategies (FFR and IVUS). The study included 154 patients who had hemodynamically significant long lesions, necessitating a stent length of 30 mm or more. The procedural outcomes were functional PCI result immediately post-PCI and at 9-12 months after treatment. Clinical outcomes included target vessel failure (TVF) and functional target vessel restenosis rate during follow-up.

RESULTS

Baseline clinical characteristics and FFR (0.65 [0.55-0.71]) did not differ significantly between the two groups and the left anterior descending artery was treated in 82% of cases. The FFR optimization strategy resulted in a significantly shorter stented segment (49 mm vs. 63 mm, p = 0.001) compared to the IVUS optimization strategy. Although the rates of optimal functional PCI result (FFR > 0.9) did not significantly differ between the FFR and IVUS optimization strategies, a proportion of patients in the FFR group (12%) experienced poor post-PCI functional outcome with FFR values ≤ 0.8, which was not observed in the IVUS group. At the 9-12 month follow-up, 20% of patients in the FFR group had target-vessel-related myocardial ischemia, compared to 6% in the IVUS group. The rates of TVF and functional target vessel restenosis during follow-up were also numerically higher in the FFR optimization group.

CONCLUSIONS

The use of FFR PCI optimization strategy in the treatment of long coronary artery lesions is associated with a higher incidence of poor functional PCI result and larger myocardial ischemia burden at follow-up compared to the IVUS optimization strategy. However, this discrepancy did not translate into a statistically significant difference in clinical outcomes. This study highlights the importance of using IVUS to optimize long lesions functional PCI outcomes.

Intravascular Ultrasound Guidance Is Associated with a Favorable One-Year Target Vessel Failure Rate and No Residual Myocardial Ischemia after the Percutaneous Treatment of Very Long Coronary Artery Lesions

Background: Studies have shown that percutaneous coronary intervention (PCI) in long coronary artery lesions (≥30 mm) is associated with more frequent target vessel failure (TVF), and a significant proportion of patients have lesions that continue to induce ischemia after PCI (FFR ≤ 0.8). We investigated the impact of intravascular ultrasound (IVUS) on the functional PCI result and one-year TVF rate after the percutaneous treatment of long coronary artery lesions. Methods: A total of 80 patients underwent IVUS-guided PCI in long coronary artery lesions. The PCI results were validated with IVUS and FFR. Procedural outcomes were the proportion of patients with: (1) optimal physiology result (post PCI FFR value ≥ 0.9); (2) optimal anatomy result (all IVUS PCI optimization criteria met); and (3) optimal physiology and anatomy result. The clinical outcome was TVF during a one-year follow-up (target vessel (TV)-related death, TV myocardial infarction, ischemia-driven TV revascularization). Results: The mean stented segment length was 62 mm. The target vessel (TV) was the left anterior descending artery in 82.5% of cases. There were no patients with residual ischemia (FFR ≤ 0.8) after PCI. Optimal coronary flow (FFR ≥ 0.9) was achieved in 37.5%; optimal anatomy, as assessed by IVUS, was achieved in 68.4%; and both optimal flow and anatomy were achieved in 25% of patients. Target vessel failure during the 12-month follow-up was 2.5%. Conclusions: In the percutaneous treatment of very long coronary artery lesions, the use of IVUS guidance is associated with a low TVF rate during a one-year follow-up and no residual myocardial ischemia, as assessed by FFR.

Validation of novel 3-dimensional quantitative coronary angiography based software to calculate fractional flow reserve post stenting

OBJECTIVES

To validate novel dedicated 3D-QCA based on the software to calculate post PCI vessel-FFR (vFFR) in a consecutive series of patients, to assess the diagnostic accuracy, and to assess inter-observer variability.

BACKGROUND

Low post percutaneous coronary intervention (PCI) fractional flow reserve (FFR) predicts future adverse cardiac events. However, FFR assessment requires the insertion of a pressure wire in combination with the use of a hyperemic agent.

METHODS

FAST POST study is an observational, retrospective, single-center cohort study. One hundred patients presenting with stable angina or non ST-elevation myocardial infarction, who underwent post PCI FFR assessment using a dedicated microcatheter were included. Two orthogonal angiographic projections were acquired to create a 3D reconstruction of the coronary artery using the CAAS workstation 8.0. vFFR was subsequently calculated using the aortic root pressure.

RESULTS

Mean age was 65±12 years and 70% were male. Mean microcatheter based FFR and vFFR were 0.91±0.07 and 0.91±0.06, respectively. A good linear correlation was found between FFR and vFFR (r = 0.88; p <.001). vFFR had a higher accuracy in the identification of patients with FFR values <0.90, AUC 0.98 (95% CI: 0.96-1.00) as compared with 3D-QCA AUC 0.62 (95% CI: 0.94-0.74). Assessment of vFFR had a low inter-observer variability (r = 0.95; p <.001).

CONCLUSION

3D-QCA derived post PCI vFFR correlates well with invasively measured microcatheter based FFR and has a high diagnostic accuracy to detect FFR <0.90 with low inter-observer variability.

Physiological assessment after percutaneous coronary intervention: the hard truth

Physiologically guided revascularization, using Fractional Flow Reserve (FFR) or instantaneous wave free ratio (iFR) has been demonstrated to be associated with better long-term outcomes compared to an angiographically-guided strategy, mainly avoiding inappropriate coronary stenting and its associated adverse events. On the contrary, the role of invasive physiological assessment after percutaneous coronary intervention (PCI) is much less well established. However, a large body of evidence suggests that a relevant proportion of patients undergoing PCI with a satisfying angiographic result show instead a suboptimal functional product with a potentially negative prognostic impact. For this reason, many efforts have been focused to identify interventional strategies to physiologically optimize PCI. Measuring the functional result after as PCI, especially when performed after a physiological assessment, implies that the operator is ready to accept the hard truth of an unsatisfactory physiological result despite angiographically optimal and, consequently, to optimize the product with some additional effort. The aim of this review is to bridge this gap in knowledge by better defining the paradigm shift of invasive physiological assessment from a simple tool for deciding whether an epicardial stenosis has to be treated to a thoroughly physiological approach to PCI with the suggestion of a practical flow chart.

Post-stenting fractional flow reserve vs coronary angiography for optimisation of percutaneous coronary intervention: TARGET-FFR trial

Aims 

A fractional flow reserve (FFR) value ≥0.90 after percutaneous coronary intervention (PCI) is associated with a reduced risk of adverse cardiovascular events. TARGET-FFR is an investigator-initiated, single-centre, randomized controlled trial to determine the feasibility and efficacy of a post-PCI FFR-guided optimization strategy vs. standard coronary angiography in achieving final post-PCI FFR values ≥0.90.

Methods and results 

After angiographically guided PCI, patients were randomized 1:1 to receive a physiology-guided incremental optimization strategy (PIOS) or a blinded coronary physiology assessment (control group). The primary outcome was the proportion of patients with a final post-PCI FFR ≥0.90. Final FFR ≤0.80 was a prioritized secondary outcome. A total of 260 patients were randomized (131 to PIOS, 129 to control) and 68.1% of patients had an initial post-PCI FFR <0.90. In the PIOS group, 30.5% underwent further intervention (stent post-dilation and/or additional stenting). There was no significant difference in the primary endpoint of the proportion of patients with final post-PCI FFR ≥0.90 between groups (PIOS minus control 10%, 95% confidence interval −1.84 to 21.91, P = 0.099). The proportion of patients with a final FFR ≤0.80 was significantly reduced when compared with the angiography-guided control group (−11.2%, 95% confidence interval −21.87 to −0.35], P = 0.045).

Conclusion 

Over two-thirds of patients had a physiologically suboptimal result after angiography-guided PCI. An FFR-guided optimization strategy did not significantly increase the proportion of patients with a final FFR ≥0.90, but did reduce the proportion of patients with a final FFR ≤0.80.

Insufficient recovery of fractional flow reserve even after optimal implantation of drug-eluting stents: 3-year outcomes from the FUJI study

BACKGROUND

Adequate improvement in fractional flow reserve (FFR) is not necessarily achieved in some cases of drug-eluting stent (DES) implantation, even when imaging confirms successful placement. We hypothesized that post-stent FFR may be associated with advanced diffuse atherosclerotic condition. We explored the relationships between FFR values after DES implantation (post-stent FFR).

METHODS

A total of 218 patients were included in this prospective, multicenter study and were divided into two groups: adequate FFR group (post-stent FFR >0.80, n=176) and inadequate FFR group (post-stent FFR ≤0.80, n=42). The primary endpoint was a major adverse cardiovascular event (MACE) including cardiac death, non-fatal myocardial infarction (MI), unplanned coronary revascularization, and hospitalization for heart failure. The secondary endpoints were event rate of all-cause death, non-fatal MI, unplanned coronary revascularization, non-fatal stroke, and hospitalization for heart failure.

RESULTS

During follow-up of 31.4±8.7 months, 34 patients (16%) had cardiovascular events. Inadequate FFR group was significantly associated with higher risk of MACE (hazard ratio: 3.86; 95% confidence interval: 1.17-12.76, p=0.026; log-rank p=0.027). In particular, the incidence of unplanned coronary revascularization on non-target lesions was significantly higher in the inadequate FFR group (log-rank p=0.031).

CONCLUSIONS

Post-stent FFR ≤0.80 was associated with a high incidence of non-target lesion revascularization and could be a surrogate marker for advanced atherosclerotic condition in the vessels of the entire coronary artery.

Prospective Evaluation of the Strategy of Functionally Optimized Coronary Intervention

Background

Long‐term outcomes after percutaneous coronary intervention (PCI) relate in part to residual ischemia in the treated vessel, as reflected by post‐PCI fractional flow reserve (FFR). The strategy of FFR after PCI and treatment of residual ischemia—known as functionally optimized coronary intervention (FCI)—may be feasible and capable of improving outcomes.

Methods and Results

Feasibility and results of FCI using an optical‐sensor pressure wire were prospectively evaluated in an all‐comer population with 50% to 99% lesions and ischemic FFR (≤0.80; ClinicalTrials.gov identifier NCT03227588). FCI was attempted in 250 vessels in 226 consecutive patients. The PCI success rate was 99.6% (249/250 vessels). FCI technical success—that is, FFR before and after PCI and PCI itself using the FFR wire—was 92% (230/250 vessels). Incidence of residual ischemia in the treated vessel was 36.5%. Approximately a third of these vessels (34.5%, n=29) were considered appropriate for further intervention, with FFR increasing from 0.71±0.07 to 0.81±0.06 (P<0.001). Pressure wire pullback showed FFR ≤0.8 at distal stent edge was 7.9% and 0.7% proximal to the stent. FFR increase across the stent was larger in the ischemic than in the nonischemic group (0.06 [interquartile range: 0.04–0.08] versus 0.03 [interquartile range: 0.01–0.05]; P<0.0001) compatible with stent underexpansion as a contributor to residual ischemia.

Conclusions

FCI is a feasible and safe clinical strategy that identifies residual ischemia in a large proportion of patients undergoing angiographically successful PCI. Further intervention can improve ischemia. The impact of this strategy on long‐term outcomes needs further study.

Analysis of the clinical value of fractional flow reserve for prognosis evaluation of patients of percutaneous coronary intervention

We investigated the clinical value of fractional flow reserve (FFR) for the prognostic evaluation of patients with percutaneous coronary intervention. We enrolled 120 patients who were admitted to the hospital to undergo percutaneous coronary intervention for acute coronary syndromes between May 2014 and June 2015. The 120 patients were divided into two groups, the observation group and the control group, according to the post-surgery level of FFR. Each cohort contained 60 patients. These patients were divided into the occurrence group (n=45) and the non-occurrence group (n=75), classified according to the occurrence of major adverse cardiovascular events (MACE). There were no statistically significant differences in the comparison of the occurrence rate of MACE within 30 days after surgery, such as lethal or non-lethal myocardial infarction or non-lethal cerebrovascular events, between the observational group and the control group (P>0.05). For the observation group, the 1-year survival cases were 56 with a survival rate of 93.3%, and 2-year survival cases were 50 with a survival rate of 83.3%. In the control group, the 1-year and 2-year survival cases were respectively 55 and 49 (survival rate of 91.7 and 81.7%). The occurrence rates of hyperlipidemia and ratio of patients with a history of smoking and drinking in the occurrence group were significantly higher than those in the non-occurrence group (P<0.05). The mean arterial pressure in the occurrence group was significantly higher than that in the non-occurrence group (P<0.05). Heart rate in the occurrence group is significantly faster than that in the non-occurrence group (P<0.05) and the stenosis degree in the occurrence group was significantly higher than that in the non-occurrence group (P<0.05). The left ventricular ejection fraction (LVEF) before surgery in the occurrence group was significantly lower than that in the non-occurrence group (P<0.05). There were no remarkable differences in comparison of the pre-treatment FFR between the occurrence group and the non-occurrence group (P>0.05), but the post-treatment FFR in the occurrence group was significantly lower than that in the non-occurrence group (P<0.05). Increased blood fat, a history of smoking and drinking, augmented mean arterial pressure, accelerated heart rate, severe coronary artery stenosis and the remarkably decreased LVEF were all identified as independent risk factors leading to major adverse myocardial events. The sum of specificity and sensitivity of treatment reached the peak when the post-surgery FFR was 0.875, the calculated sensitivity was 82.4%, and the specificity was 50.8%. In conclusion, measurement of FFR after percutaneous coronary intervention could not only effectively evaluate the target vessel revascularization, but also predict the occurrence of major adverse myocardial events 1 year after surgery, which could serve as the guidance for clinical treatment.

Clinical and angiographic predictors of persistently ischemic fractional flow reserve after percutaneous revascularization

AIMS

Despite optimal angiographic results after percutaneous coronary intervention (PCI), some lesions may continue to produce ischemia under maximal hyperemia. We evaluated the factors associated with persistently ischemic fractional flow reserve (FFR) after angiographically successful PCI.

METHODS AND RESULTS

A total of 574 consecutive patients with 664 lesions undergoing PCI who had FFR pre- and post-PCI were analyzed. Percutaneous coronary intervention led to effective ischemia reduction from pre-FFR (0.65±0.14) to post-FFR (0.87±0.08; ∆FFR 0.22±0.16, P<.001). There were 63 (9.5%) lesions with a persistently ischemic FFR of ≤0.80 despite optimal angiographic PCI results. Multivariate analysis revealed the presence of diffuse disease (odds ratio [OR] 3.54, 95% CI 1.80-6.94, P<.01), left anterior descending artery PCI (OR 8.35, 95% CI 3.82-18.27, P<.01), use of intravenous adenosine for inducing hyperemia (OR 3.95, 95% CI 2.0-7.84, P<.01), and pre-PCI FFR (OR 0.03, 95% CI 0.004-0.23, P<.01) as independent predictors of persistently ischemic FFR (≤0.80) after PCI. The predictive accuracy of this model was robust, with an area under the curve of 0.85 (95% CI 0.82-0.88).

CONCLUSION

Multiple factors are associated with persistently ischemic FFR after angiographically optimal PCI. It is recommended that in lesions with the above-identified factors, FFR should be remeasured after PCI, and if abnormal, further measures should be undertaken for functional optimization.