Borderline Fractional Flow Reserve Research Articles

Abstract 14666: Coronary Arterial Calcification Influences Fractional Flow Reserve: Comparison of Guide Wire Type FFR With Vasodilator and FFRangio Without Vasodilator

Introduction: Fractional flow reserve (FFR) measures percutaneous coronary intervention (PCI) performance. FFR was determined by guide wire (GW)-type FFR. It is now evaluated by computed tomography (CT; FFRCT) or invasive coronary angiography (FFRangio; CathWorks, USA), whereby coronary arteries are traced on a conventional angiogram from three different angles to form three-dimensional images; the calculated FFR is FFRangio. In contrast to GW-type FFR, FFRangio does not need a vasodilator drug (e.g. nicorandil) load or GW. Hypothesis: Coronary calcification may influence the effect of vasodilator drugs, causing a difference between FFRangio and GW-type FFR depending on coronary calcium score (CCS). Methods: FFRangio and GW-type FFR (SJN, Zeon, ACIST) were simultaneously evaluated at catheter examinations in 11 coronary arteries from 9 patients before PCI (six males, mean age 72±11 years). Nicorandil (2 mg) was directly injected when measuring GW-type FFR. Cardiac CT was performed to measure CCS. Results: The correlation coefficients between FFR magnitude (=mean of FFRangio and GW-type FFR) and CCS in all vessels, and a vessel with FFR measurement, were -0.845 and -0.843, respectively. The correlation coefficients between difference in FFRangio minus GW-type FFR and CCS in all vessels, and a vessel with FFR measurement, were 0.627 and 0.752, respectively. The greater the CCS of both all vessels and a vessel in FFR measurements, the smaller the FFR. The greater the CCS of both all vessels and a vessel with FFR measurement, the greater the difference in FFRangio minus GW-type FFR (Figures). This may indicate the greater the CCS, the smaller the vasodilation effect of a direct nicorandil injection. Conclusions: Of GW-type FFR, FFRangio, and FFR CT, only GW-type FFR requires a vasodilator injection. Coronary arteries, known to cause blooming artifacts and impair the accuracy of FFRCT, also influence vasodilator effects, especially with borderline FFR (0.75-0.80).

Five-Year Outcomes After Fractional Flow Reserve–Based Deferral of Revascularization in Chronic Coronary Syndrome: Final Results From the J-CONFIRM Registry

Little large-scale data is available about the long-term (beyond 3 years) clinical outcomes after fractional flow reserve (FFR)-based deferral of revascularization in clinical practice. We sought to assess the 5-year outcomes after deferral of revascularization based on FFR. The J-CONFIRM registry (Long-Term Outcomes of Japanese Patients With Deferral of Coronary Intervention Based on Fractional Flow Reserve in Multicenter Registry) prospectively enrolled 1263 patients with 1447 lesions in whom revascularization was deferred based on FFR from 28 Japanese centers. The primary study end point was the cumulative 5-year incidence of target vessel failure (TVF), including cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization. Five-year follow-up was completed in 92.2% of patients. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization (9.8%). Cardiac death and target vessel-related myocardial infarction were 1.9% and 0.95%, respectively. Cumulative 5-year incidence of TVF was similar between the FFR 0.75 to 0.80 and 0.81 to 0.85 groups even after adjustment for baseline characteristics (12.2% versus 13.0%, inverse probability-weighted hazard ratio, 0.86 [95% CI, 0.46-1.60]; P=0.63). Compared with the almost normal FFR (0.86-1.00) group, the significant (<0.75) and borderline (0.75-0.85) FFR groups showed a higher incidence of TVF at 5 years (29.9% versus 12.8% versus 8.6%, P<0.001). Independent predictors of the 5-year TVF were hemodialysis, FFR value, left main coronary artery lesion, prior percutaneous coronary intervention, and male sex. The 5-year TVF rate was 11.6% in deferred lesions, mainly driven by clinically driven target vessel revascularization. Notably, cardiac death and target vessel-related myocardial infarction rarely occurred during the follow-up. Our findings highlight the long-term safety of FFR-based deferral of revascularization in patients with chronic coronary syndrome. Registration: URL: https://www.umin.ac.jp/ctr; Unique identifier: UMIN000014473.

Fractional flow reserve-guided treatment in coronary artery disease: Clinical practice.

The assessment of functional severity of moderate coronary stenoses is challenging. Coronary angiography remains the standard technique for diagnosis, although, due to its limitations, it is frequently insufficient to detect relevant myocardial ischemia. Fractional flow reserve (FFR) is defined as the ratio between the mean hyperemic coronary artery pressure distal to the lesion and mean pressure in the aorta. The FFR measurement is currently supported by guidelines to evaluate the hemodynamic significance of lesions. Proper identification of patients that have the potential to benefit from revascularization is crucial. Based on already published literature, we focus on the long-term follow-up of patients with FFR-driven treatment. We also provide a review of specific clinical cases such as borderline FFR values, comorbidities or lesions in anatomical risk locations, in which interpretation can be challenging during the physiological assessment. The aim of this paper is to provide an overview of the evidence of FFR implementation in daily clinical practice and determine issues that raise doubts.

Long-term variations of FFR and iFR after transcatheter aortic valve implantation

Long-term variations of fractional flow reserve (FFR) and instantaneous wave-free-ratio (iFR) after transcatheter aortic valve implantation (TAVI) have not been previously assessed.A total of 23 coronary lesions in 14 patients with aortic stenosis (AS) underwent physiology assessment at baseline, immediately after TAVI and at 14(7–29) months of follow-up.The angiographic severity of the lesions did not progress at follow-up (54[45–64] vs 54[49–63], p = .53). Overall, FFR (0.87[0.85–0.92] vs 0.88[0.82–0.92], p = .45) and iFR (0.88[0.85–0.96] vs 0.91[0.86–0.97], p = .30) did not change significantly compared with the baseline.FFR decreased in 3(13%) lesions with abnormal baseline value, whereas it remained stable in lesions with FFR > 0.80. Conversely, iFR did not show a systematic trend at long-term after TAVI. However, iFR demonstrated a higher reclassification rate at follow-up compared with FFR (p = .02).In conclusions, in this exploratory study, only minor variations of coronary physiology indices were observed at long-term after TAVI. Nevertheless, caution should be exercised in the interpretation of borderline FFR and iFR values in severe AS.

Utility of Imaging Modalities in Coronary Lesions With Borderline Fractional Flow Reserve

BackgroundCoronary intervention is routinely deferred in intermediate lesions with fractional flow reserve (FFR) ≥ 0.80. Patients with borderline FFR (0.80–0.85) who were initially deferred, have been shown to have higher risk of future interventions; however, the data is limited, and the long term prognosis in these patients remains unknown. We assessed the utility of adjunctive imaging modalities to determine the need for intervention in lesions with borderline FFR. MethodsWe retrospectively evaluated consecutive patients who underwent coronary angiography at Einstein Medical Center from January 2013 to April 2016. All patients with borderline FFR (0.80–0.85) were included. Patients were divided into Defer or Perform intervention groups based on additional available or procured clinical data. The Perform group was further stratified into intervention With or Without adjunctive imaging guidance (including intravascular ultrasound, optical coherence tomography, echocardiography, and exercise or pharmacologic stress test). Follow-up data was collected for all patients, which included future target lesion revascularization (TLR) and major adverse cardiac events (MACE; all-cause and cardiovascular mortality and acute coronary syndromes). ResultsA total of 196 patients were eligible. Median (IQR) FFR in Perform and Defer groups was 0.81 (0.8–0.83) and 0.84 (0.82–0.85) respectively. Median (IQR) follow up was 21 (13–29) and 25 (15–36) months respectively. Overall MACE rate in Perform group (n = 101) was 20.8% (n = 21) and Defer group (n = 95) was 15.8% (n = 15). The stratified MACE rate in Perform group With imaging guidance (n = 57) was 17.5% (n = 10) and Without imaging guidance (n = 44) was 25% (n = 11). Overall, the FFR only guided management (n = 196) led to MACE rate of 18.4% (n = 36); whereas, FFR With imaging guidance (n = 136) led to MACE rate of 16.2% (n = 22). The p values were non-significant in each of the above group comparisons due to relatively low numbers with trends as noted. ConclusionsOur study suggests that intervention of coronary lesions with borderline FFR under imaging guidance, although not significant, trends towards improved cardiovascular outcomes compared with intervention in this group without adjunctive imaging. These findings are merely speculative without achieving statistical significance in a small subset and need to be further validated in a large scale prospective study.

Renal dysfunction is associated with lower incidence of positive fractional flow reserve values in patients with severe hypertension.

Renal dysfunction, an important predictor of cardiovascular mortality, is paradoxically associated with a lower incidence of positive coronary fractional flow reserve (FFR) values, possibly due to renal disease-associated myocardial microvascular dysfunction. It is unknown if this relationship is influenced by arterial hypertension, a condition strongly associated with renal- and microvascular dysfunction. The incidence of positive (<0.81) FFR values was retrospectively evaluated in consecutive patients with intermediate severity coronary artery lesions that were either associating or not associating renal dysfunction (creatinine clearance, CrCl <90 mL/min/1.73 m2), and had mild/moderate or severe arterial hypertension (treated by <3 or ≥3 different drugs). Positive FFR values were found in 49.5% of the 109 included patients, with a significantly lower incidence in those with renal dysfunction: 23 vs. 31 cases (39.7% vs. 60.8%, P=0.03). However, uni- and multivariate subpopulation analysis evidenced that renal dysfunction was a significant independent predictor of fewer positive FFR results only in severely hypertensive patients (univariate P values for mild/moderate and severe hypertension: 0.80 and <0.01, respectively; multivariate P in severely hypertensive patients: 0.04). This categorization significantly restricted the number of borderline FFR results (0.75-0.80) where measurement interpretation could be challenging because of renal dysfunction (from 13.8% to 4.6% of the whole study population, P=0.03). In the current study renal dysfunction was independently associated with a significantly higher incidence of negative FFR results in patients with intermediate severity coronary artery lesions only in the presence of severe arterial hypertension. This observation should be confirmed by large-scale prospective clinical trials.

Intravascular ultrasound-based machine learning for predicting fractional flow reserve in intermediate coronary artery lesions

Background and aimsIntravascular ultrasound (IVUS)-derived morphological criteria are poor predictors of the functional significance of intermediate coronary stenosis. IVUS-based supervised machine learning (ML) algorithms were developed to identify lesions with a fractional flow reserve (FFR) ≤0.80 (vs. >0.80). MethodsA total of 1328 patients with 1328 non-left main coronary lesions were randomized into training and test sets in a 4:1 ratio. Masked IVUS images were generated by an automatic segmentation model, and 99 computed IVUS features and six clinical variables (age, gender, body surface area, vessel type, involved segment, and involvement of the proximal left anterior descending artery) were used for ML training with 5-fold cross-validation. Diagnostic performances of the binary classifiers (L2 penalized logistic regression, artificial neural network, random forest, AdaBoost, CatBoost, and support vector machine) for detecting ischemia-producing lesions were evaluated using the non-overlapping test samples. ResultsIn the classification of test set lesions into those with an FFR ≤0.80 vs. >0.80, the overall diagnostic accuracies for predicting an FFR ≤0.80 were 82% with L2 penalized logistic regression, 80% with artificial neural network, 83% with random forest, 83% with AdaBoost, 81% with CatBoost, and 81% with support vector machine (AUCs: 0.84–0.87). With exclusion of the 28 lesions with borderline FFR of 0.75–0.80, the overall accuracies for the test set were 86% with L2 penalized logistic regression, 85% with an artificial neural network, 87% with random forest, 87% with AdaBoost, 85% with CatBoost, and 85% with support vector machine. ConclusionsThe IVUS-based ML algorithms showed good diagnostic performance for identifying ischemia-producing lesions, and may reduce the need for pressure wires.

Intravascular ultrasound characteristics in patients with intermediate coronary lesions and borderline fractional flow reserve measurements

Revascularization of borderline fractional flow reserve (FFR) is controversial and the morphologic characteristics of borderline FFR lesions are not well known. The objective of this study was to determine the intravascular ultrasound (IVUS) characteristics in intermediate coronary lesions with borderline FFR in patients with intermediate coronary artery stenosis (40%–70% diameter stenosis).Both IVUS and FFR were performed in a total of 228 left anterior descending arteries. We divided them into 3 groups by FFR value: ischemic (n = 46, FFR < 0.75), borderline (n = 71, FFR 0.75 to ≤0.80), and non-ischemic (n = 111, FFR > 0.80). We compared the IVUS parameters, including minimum lumen area, lesion length, plaque burden, and volumetric analysis among the 3 groups.In the IVUS analysis, the minimum lumen area was smaller (2.5 ± 0.6 vs. 2.7 ± 0.7 vs. 3.4 ± 1.2 mm2, P < .001); lesion length was longer (23.6 ± 8.4 vs. 23.6 ± 7.4 vs. 17.4 ± 6.8 mm, P < .001); plaque burden was larger (76.1 ± 9.6 vs. 73.9 ± 7.5 vs. 69.8 ± 9.5%, P < .001); plaque volume was larger (173.0 ± 78.3 vs. 167.7 ± 75.0 vs. 129.5 ± 79.1 mm3, P < .01); and percent atheroma volume was larger (57.9 ± 7.5 vs. 57.6 ± 6.6 vs. 53.9 ± 8.0%, P < .01) in the ischemic and borderline groups compared with the non-ischemic group, respectively. However, post-hoc analyses showed there were no significant differences between the ischemic and borderline group for all IVUS parameters.There were no differences in IVUS characteristics between borderline and functionally significant FFR, but the amount of atheromatous plaque was more severe in these 2 groups than in the non-ischemic group.

CRT-100.46 Utility Of Imaging Modalities In Coronary Lesions With Borderline Fractional Flow Reserve

Coronary intervention is routinely deferred in intermediate coronary lesions with fractional flow reserve (FFR) ≥0.80. Recently, patients with borderline FFR (0.80-0.85) who were initially deferred have been shown to have higher risk of future interventions; however, the data are limited, and the

Diagnostic one-stop-shop in suspected coronary artery disease gets closer. Coronary computed tomography angiography based fractional flow reserve.

Diagnostic one-stop-shop in suspected coronary artery disease gets closer. Coronary computed tomography angiography based fractional flow reserve.

Outcomes of Coronary Stenoses Deferred Revascularization for Borderline Versus Nonborderline Fractional Flow Reserve Values

Current evidence supports deferral of revascularization for lesions with fractional flow reserve (FFR) values >0.80. The natural history after deferral of revascularization of lesions with borderline FFR values is unknown. This study evaluated the outcomes of patients after deferred revascularization of coronary stenoses based on a borderline FFR value. We retrospectively studied 720 patients with 881 intermediate-severity coronary stenoses who underwent FFR assessment from October 2002 to July 2010 and were deferred revascularization. Patients were divided into gray zone (0.75 to 0.80), borderline (0.81 to 0.85), and nonborderline (>0.85) FFR groups. Any subsequent percutaneous coronary intervention or coronary artery bypass grafting of a deferred stenosis during follow-up was classified as a deferred lesion intervention (DLI). Patient and/or lesion characteristics and clinical outcomes were compared between the FFR groups using univariate and propensity score-adjusted inverse probability of weighting Cox proportional hazards analyses. During a mean follow-up of 4.5 ± 2.1 years, 157 deferred lesions (18%) underwent DLI by percutaneous coronary intervention (n = 117) or coronary artery bypass grafting (n = 40). No statistically significant differences were observed in clinical outcomes between the gray zone and borderline FFR groups. Lesions with a borderline FFR were associated with a significantly higher risk of DLI compared with lesions with nonborderline FFR values (hazard ratio 1.63, 95% confidence interval 1.14 to 2.33, p = 0.007). Lesions deferred revascularization because of a borderline FFR (0.81 to 0.85) were associated with a higher risk of DLI compared with lesions with a nonborderline FFR (>0.85). Further study is needed to determine the optimal management of coronary stenoses with a borderline FFR value.

TCT-705: Intravascular Ultrasound Characteristics in Patients with Intermediate Coronary Lesions and Borderline Fractional Flow Reserve Measurements

TCT-705: Intravascular Ultrasound Characteristics in Patients with Intermediate Coronary Lesions and Borderline Fractional Flow Reserve Measurements

The Prognostic Value of Combined Fractional Flow Reserve and TIMI Frame Count Measurements in Patients with Stable Angina Pectoris and Acute Coronary Syndrome

The aim of this study was to evaluate the prognostic value of different fractional flow reserve (FFR) cutoff values and corrected thrombolysis in myocardial infarction frame (TIMI) count (CTFC) measurements in a series of consecutive patients with moderate coronary lesions, including patients with unstable angina, myocardial infarction, and/or positive noninvasive functional test findings. We included 162 consecutive coronary patients in whom revascularization of a moderate coronary lesion was deferred based on a FFR value ≥0.75. Patients were divided according to the results of the intracoronary pressure and flow measurements into four groups: group A: 0.75 ≤ FFR ≤ 0.85 and CTFC > 28 (n=22), group B: 0.75 ≤ FFR ≤ 0.85 and CTFC ≤ 28 (n = 55), group C: 0.85 < FFR and CTFC > 28 (n = 19), and group D: 0.85 < FFR and CTFC ≤ 28 (n = 66). Adverse cardiac events and the presence of angina were evaluated at follow-up. At a mean follow-up of 18 ± 10 months, cardiac event rate in patients with 0.75 ≤ FFR ≤ 0.85 and FFR > 0.85 were 22% and 9%, respectively (P = 0.026) and also, a trend was observed toward a higher cardiac event rate in case of an abnormal CTFC (CTFC > 28) compared to a normal CTFC (24% vs 12%, P = 0.066). Furthermore, a significantly higher cardiac event rate was observed when group A was compared to group D (31.8% vs 7.6%, respectively, P = 0.004). Patients with potential microvascular dysfunction and borderline FFR values should be interpreted with caution, and management strategies should be guided not only by pressure measurement, but also by possibly supplementary clinical risk stratification and noninvasive tests.

Clinical Outcome Following Conservative vs Revascularization Therapy in Patients With Stable Coronary Artery Disease and Borderline Fractional Flow Reserve Measurements

Fractional flow reserve (FFR) measurements in the so-called gray-zone range of > or = 0.75 and < or =0.80 are associated with uncertainty concerning the guidance of patient therapy. It is unclear whether any difference in clinical outcome exists when revascularization treatment of FFR-evaluated lesions in this borderline range is deferred or performed. The objective of this study is to compare the clinical outcome of these patients with respect to their recommended treatment strategy. Out of a single center database of 900 consecutive patients with stable coronary artery disease, 97 patients with borderline FFR measurements were identified and included in the study. The rate of major adverse cardiac events (MACE; cardiac death, myocardial infarction (MI), coronary revascularization) and the presence of angina were evaluated at follow-up. A total of 48 patients were deferred from revascularization and 49 patients underwent revascularization. There was no difference in risk profile between these groups. At a mean follow-up of 24+/-16 months, event-free survival in the deferred group was significantly better regarding overall MACE, combined rate of cardiac death, and MI, as well as MACE related to the FFR-evaluated vessel. No difference with regard to the presence of angina was observed. Patients with coronary lesions in the borderline FFR range can be deferred from revascularization without putting them at increased risk for major adverse events. Revascularization may be considered in the course of therapy on an individual basis if typical angina persists or worsens despite maximal medical treatment.

Abstract 4471: Long-Term Follow-Up After Deferral of Percutaneous Coronary Intervention (PCI) in Patients With Moderate Coronary Lesions and Borderline Fractional Flow Reserve Measurements

Background: Many studies have demonstrated that deferral of percutaneous coronary intervention (PCI) on the basis of a myocardial fractional flow reserve (FFR) ≥0.75 is associated with a very low coronary event rate. However, some groups have empirically chosen the cut-off value of 0.80 rather than 0.75 for decision to defer PCI and the FFR measurement between 0.75 and 0.80 has been established as a grey zone. The aim of this study was to evaluate the long-term clinical outcomes of patients with moderate coronary lesions and FFR measurements between 0.75 and 0.80. Methods: The study included 125 anigiographically moderate coronary lesions (&gt;50% diameter stenosis by visual assessment) in 125 patients but in whom the PCI was deferred on the basis of an FFR ≥ 0.75. The FFR was calculated as the ratio of mean distal pressure divided by the proximal pressure during hyperemia. Patients were divided into two groups according to the result of FFR: ≥ 0.80 (n=99, group 1) and between 0.75 and 0.79 (n=26, group 2). We evaluated the long-term major adverse cardiovascular events (MACE) related and unrelated to the FFR-evaluated lesion. Results: During a follow-up period of 82 ± 29 months (mean ± SD), The Kaplan-Meier event-free survival curves showed that group 2 was poorer than group 1 in prognosis (p=0.0148). The incidence of MACE unrelated FFR-evaluated lesion in group 1 was equivalent to that in group 2 (p=0.96). Conclusions: In patients with moderate coronary lesions and borderline FFR measurements, deferral of PCI was associated with a higher rate of MACE related to the FFR-evaluated lesion. FFR cut-off point of 0.80 instead of 0.75 may be more appropriate for deferring PCI.

Comparison of medical treatment and coronary revascularization in patients with moderate coronary lesions and borderline fractional flow reserve measurements

(1) To evaluate the clinical outcomes of patients with moderate coronary lesions and borderline fractional flow reserve (FFR) measurements (between 0.75 and 0.80), comparing those who underwent coronary revascularization (CR) to those who had medical treatment (MT), and (2) to determine the predictive factors of major adverse cardiac events (MACE) at follow-up. A total of 107 consecutive patients (mean age 62 +/- 10 years) with at least one moderate coronary lesion (mean percent diameter stenosis 47 +/- 12%) evaluated by coronary pressure wire with FFR measurement between 0.75 and 0.80 (mean 0.77 +/- 0.02) were included in the study. MACE [CR, myocardial infarction (MI), cardiac death) and the presence of angina were evaluated at follow-up. Sixty-three patients (59%) underwent CR and 44 patients (41%) had MT, with no clinical differences between groups. At a mean follow-up of 13 +/- 7 months, MACE related to the coronary lesion evaluated by FFR were higher in the MT group compared with CR group (23% vs. 5%, P = 0.005). Most MACE consisted of CRs, with no differences between groups in MI and cardiac death rate at follow-up. Both MT and FFR measurements in an artery supplying a territory with previous MI were independent predictive factors of MACE at follow-up, respectively (hazard ratio 5.2, 95% CI 1.4-18.9, P = 0.01; hazard ratio 4.1, 95% CI 1.1-15.3, P = 0.03). The presence of angina at follow-up was more frequent in the MT group compared with the CR group (41% vs. 9%, P = 0.002). In patients with moderate coronary lesions and borderline FFR measurements deferral of revascularization was associated with a higher rate of MACE (CR) and a higher prevalence of angina at follow-up, especially in those with previous MI in the territory evaluated by FFR. Further prospective randomized studies should confirm whether or not an FFR cut-off point of 0.80 instead of 0.75 would be more appropriate for deferring CR in these cases.

Should we revascularize patients with moderate coronary lesions and borderline fractional flow reserve measurements?

Should we revascularize patients with moderate coronary lesions and borderline fractional flow reserve measurements?

Abstract 3334: Comparison of Medical Treatment and Coronary Revascularization in Patients with Moderate Coronary Lesions and Borderline Fractional Flow Reserve Measurements

Background. There is little information available regarding deferral of revascularization in cases of fractional flow reserve (FFR) measurements in the borderline range (between 0.75 to 0.80). The objectives of this study were to evaluate the clinical outcomes of patients with moderate coronary lesions and FFR measurements between 0.75 and 0.80, comparing those who underwent coronary revascularization (CR) to those who had medical treatment (MT), and to determine the predictive factors of major adverse cardiac events (MACE) at follow-up. Methods. A total of 107 consecutive patients (mean age 62 ± 10 years) with at least one moderate coronary lesion (mean percent diameter stenosis 47 ± 12%) evaluated by coronary pressure wire with FFR measurement between 0.75 and 0.80 (mean 0.77 ± 0.02) were included in the study. Maximal hyperemia was obtained by intracoronary administration of adenosine (mean dose 215 ± 84 μg). MACE (coronary revascularization, myocardial infarction, cardiac death) and the presence of angina were evaluated at follow-up. Results. A total of 63 patients (59%) underwent CR and 44 patients (41%) had MT, with no clinical differences between groups. At a mean follow-up of 13 ± 7 months, MACE related to the coronary lesion evaluated by FFR were higher in the MT group compared to CR group (23% vs 5%, difference 18%, 95% CI 5%–30%, p=0.005). FFR measurement in an artery supplying a territory with previous myocardial infarction was the only predictive factor of MACE in the MT group (odds ratio 14.1, 95% CI 1.3–39, p=0.03). The presence of angina at follow-up was more frequent in the MT group compared to the CR group (41% vs 9%, difference 32%, 95% CI 11%–49%, p&lt;0.001). Conclusions. In patients with moderate coronary lesions and FFR measurements in the “grey zone” range deferral of revascularization was associated with a higher rate of cardiac events and a higher prevalence of angina at follow-up, especially in those with previous myocardial infarction in the territory evaluated by FFR. These results suggest that a FFR cut-off point of 0.80 rather than 0.75 might be more appropriate for deferring coronary revascularization in these cases.

The effect of drug eluting stents on cardiovascular events in patients with intermediate lesions and borderline fractional flow reserve

To assess the role of fractional flow reserve (FFR) in guiding therapy in the drug eluting stent (DES) era. FFR is a useful index for evaluation of the physiological significance of angiographically indeterminate coronary artery lesions. However, its role in the DES era is unknown. Long term outcome of 281 patients with angiographically indeterminate coronary lesions and borderline FFR (0.75 </= FFR < 0.9) was obtained. The outcome of patients who had a DES placed (n = 58), was compared with that of consecutive patients with borderline FFR that were treated by PCI with bare metal stents (BMS, n = 58), or were deferred from revascularization (n = 165). FFR was significantly higher in the deferred group (median and IQR); 0.85 (0.82 to 0.88) compared with the BMS (0.78; 0.76 to 0.82) and the DES (0.79; 0.77 to 0.82), P < 0.001. Pretreatment FFR was a significant determinant of long term event rates in the deferred patients (P = 0.002) but had no effect in patients treated by PCI. In the deferred group, there were fewer events (death, myocardial infarction, target vessel revascularization) compared with the BMS group; but no significant difference was observed between the DES and the deferred groups. In borderline FFR, long term outcome after PCI with BMS is inferior to conservative therapy or PCI with DES. While conservative management is preferable in these patients, PCI with DES may be considered in specific circumstances.

Hypertension as a predictor of adverse cardiac events in patients with borderline fractional flow reserve

Objective — The cut-off value myocardial fractional flow reserve (FFRmyo) < 0.75 identifies patients with clinically significant coronary stenosis. Normally PCI is deferred with a FFRmyo ≥ 0.75. Other clinical characteristics may affect such treatment decision.Therefore, we studied the association between baseline characteristics and clinical outcomes in an unselected patient cohort with coronary artery disease, with intermediate coronary stenosis, initially referred for PCI, but in whom the intervention was deferred on the basis of FFRmyo ≥ 0.75Methods — Angiographic analysis and follow-up were performed in 152 patients with stable or unstable angina pectoris with intermediate coronary stenosis severity and normal left ventricular func-tion.A major adverse cardiac event (MACE) was defined as postprocedural acute myocardial infarction (AMI), target vessel revascularization (TVR) and verified cardiac death.Results — More adverse cardiac events occurred in patients with 0.75 < FFRmyo < 0.80 (24/30) compared with FF ≥ 0.80 (9/97) (P< 0.001). Hypertension, diabetes and hyperlipidaemia were significantly associated with the occurrence of MACE in the univariate analyses. Logistic regression analyses showed that only hypertension remained as a significant independent predictor of MACE for patients with 0.75 ≤ FFRmyo < 0.80 (P< 0.10).Conclusion — In an unselected patient population with coronary artery disease, a FFRmyo cut-off value of 0.8 should be used in hypertensive patients to discriminate between clinically significant coronary stenosis.