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Background: Diffuse coronary artery disease affects the safety and efficacy of percutaneous coronary intervention (PCI). Pathophysiologic coronary artery disease patterns can be quantified using fractional flow reserve (FFR) pullbacks incorporating the pullback pressure gradient (PPG) calculation. This study aimed to establish the capacity of PPG to predict optimal revascularization and procedural outcomes., Methods: This prospective, investigator-initiated, single-arm, multicenter study enrolled patients with at least one epicardial lesion with an FFR ≤0.80 scheduled for PCI. Manual FFR pullbacks were used to calculate PPG. The primary outcome of optimal revascularization was defined as an FFR ≥0.88 after PCI., Results: A total of 993 patients with 1044 vessels were included. The mean FFR was 0.68±0.12, PPG 0.62±0.17, and the post-PCI FFR was 0.87±0.07. PPG was significantly correlated with the change in FFR after PCI (r=0.65 [95% CI, 0.61-0.69]; P <0.001) and demonstrated excellent predictive capacity for optimal revascularization (area under the receiver operating characteristic curve, 0.82 [95% CI, 0.79-0.84]; P <0.001). FFR alone did not predict revascularization outcomes (area under the receiver operating characteristic curve, 0.54 [95% CI, 0.50-0.57]). PPG influenced treatment decisions in 14% of patients, redirecting them from PCI to alternative treatment modalities. Periprocedural myocardial infarction occurred more frequently in patients with low PPG (<0.62) compared with those with focal disease (odds ratio, 1.71 [95% CI, 1.00-2.97])., Conclusions: Pathophysiologic coronary artery disease patterns distinctly affect the safety and effectiveness of PCI. PPG showed an excellent predictive capacity for optimal revascularization and demonstrated added value compared with an FFR measurement., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04789317., Competing Interests: Dr Collet reports receiving research grants from Biosensors, Coroventis Research, Medis Medical Imaging, Pie Medical Imaging, CathWorks, Boston Scientific, Siemens, HeartFlow, and Abbott Vascular; consultancy fees from HeartFlow, OpSens Medical, Abbott Vascular, and Philips Volcano; and has patents pending on diagnostic methods for coronary artery disease. Dr Munhoz reports a research grant provided by the CardioPath PhD programme and speaker fees from Abbott Vascular. Dr Mizukami reports receiving research grants from Boston Scientific and speaker fees from Abbott Vascular, CathWorks, and Boston Scientific. Dr Matsuo has received consulting fees from Kaneka and Zeon and speaker’s fees from Abbott Medical Japan, Boston Scientific, Philips, and Amgen. Dr Ko has received consulting fees from Canon Medical, Abbott, and Medtronic. Dr Biscaglia received research grants provided by Sahajanand Medical Technologies, Medis Medical Imaging, Eukon Srl, Siemens Healthineers, General Electric Healthcare, and Insight Lifetech. Dr Engstrøm reports speaker and advisory board fees from Abbott, Boston Scientific, and Novo Nordisk. Dr Leone reports receiving consultancy fees from Abbott and honoraria for sponsored symposia from Abbott, Medtronic, and Abiomed. Dr Fearon receives institutional research support from Abbott, Boston Scientific, and Medtronic and has consulting relationships with CathWorks and Siemens and stock options from HeartFlow. Dr Christiansen has received consulting fees from Abbott Medical Denmark A/S. Dr Yong has received minor honoraria from Abbott Vascular and research grants from Abbott Vascular and Philips. Dr Escaned is supported by the Intensification of Research Activity project INT22/00088 from the Spanish Instituto de Salud Carlos III and received speaker and advisory board member fees from Abbott and Philips. Dr Storozhenko reports a grant provided by the EAPCI Fellowship Programme. Dr West is an employee of Abbott Vascular. Dr De Potter is a paid consultant for Biosense Webster and receives grant support (institutional) and consultancy fees (institutional) from Abbott. Dr Berry receives research funding from the British Heart Foundation (grants RE/18/6134217, BHF/FS/17/26/32744, and PG/19/28/34310) and is employed by the University of Glasgow, which holds consultancy and research agreements for his work with Abbott Vascular, AstraZeneca, Boehringer Ingelheim, Coroventis Research, GlaxoSmithKline, HeartFlow, Menarini, Novartis, Servier, Siemens Healthcare, and Valo Health. Dr Collison has received consulting fees from Abbott. Dr Johnson has received consultancy or speaker fees from Abbott Vascular, Boston Scientific, Medtronic, Shockwave, and Terumo, and research grants from Abbott Vascular. Dr Amano reports receiving lecture fees from Astellas Pharma, Astra Zeneca, Bayer, Daiichi Sankyo, and Bristol Myers Squibb. Dr Perera has received research grant support from Abbott Vascular, HeartFlow, and Philips. Dr Jeremias has received consulting fees from Canon Medical, Artrya Medical, and Boston Scientific. Dr Ali reports institutional grant support from Abbott, Abiomed, Acist, Amgen, Boston Scientific, CathWorks, Canon Medical, Conavi, HeartFlow, Inari, Medtronic, the US National Institutes of Health, Nipro, OpSens Medical, Medis, Philips, Shockwave, Siemens, SpectraWAVE, and Teleflex; consulting fees from Abiomed, Astra Zeneca, Boston Scientific, CathWorks, OpSens Medical, Philips, and Shockwave; and equity in Elucid, Lifelink, SpectraWAVE, Shockwave, and VitalConnect. Dr Pijls has received research grants from Abbott and Hexacath; consultancy fees from Abbott, GE, Philips, and HeartFlow; and has equity in General Electric, Philips, and HeartFlow. Dr De Bruyne reports receiving consultancy fees from Boston Scientific and Abbott and research grants from Coroventis Research, Pie Medical Imaging, CathWorks, Boston Scientific, Siemens, HeartFlow, and Abbott Vascular. Dr Johnson received internal funding from the Weatherhead PET Center for Preventing and Reversing Atherosclerosis; has received significant institutional research support from St Jude Medical (CONTRAST [Can Contrast Injection Better Approximate FFR Compared to Pure Resting Physiology?; URL: https://www.clinicaltrials.gov; Unique identifier: NCT02184117]) and Philips Volcano (DEFINE-FLOW [Combined Pressure and Flow Measurements to Guide Treatment of Coronary Stenoses; URL: https://www.clinicaltrials.gov; Unique identifier: NCT02328820]) for other studies using intracoronary pressure and flow sensors; has an institutional licensing agreement with Boston Scientific for the smart-minimum FFR algorithm (now commercialized under 510[k] K191008); and has patents pending on diagnostic methods for quantifying aortic stenosis and TAVI physiology and on methods to correct pressure tracings from fluid-filled catheters.

Background: Previous studies comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in patients with multivessel coronary disease not involving the left main have shown significantly lower rates of death, myocardial infarction (MI), or stroke after CABG. These studies did not routinely use current-generation drug-eluting stents or fractional flow reserve (FFR) to guide PCI., Methods: FAME 3 (Fractional Flow Reserve versus Angiography for Multivessel Evaluation) is an investigator-initiated, multicenter, international, randomized trial involving patients with 3-vessel coronary artery disease (not involving the left main coronary artery) in 48 centers worldwide. Patients were randomly assigned to receive FFR-guided PCI using zotarolimus drug-eluting stents or CABG. The prespecified key secondary end point of the trial reported here is the 3-year incidence of the composite of death, MI, or stroke., Results: A total of 1500 patients were randomized to FFR-guided PCI or CABG. Follow-up was achieved in >96% of patients in both groups. There was no difference in the incidence of the composite of death, MI, or stroke after FFR-guided PCI compared with CABG (12.0% versus 9.2%; hazard ratio [HR], 1.3 [95% CI, 0.98-1.83]; P =0.07). The rates of death (4.1% versus 3.9%; HR, 1.0 [95% CI, 0.6-1.7]; P =0.88) and stroke (1.6% versus 2.0%; HR, 0.8 [95% CI, 0.4-1.7]; P =0.56) were not different. MI occurred more frequently after PCI (7.0% versus 4.2%; HR, 1.7 [95% CI, 1.1-2.7]; P =0.02)., Conclusions: At 3-year follow-up, there was no difference in the incidence of the composite of death, MI, or stroke after FFR-guided PCI with current-generation drug-eluting stents compared with CABG. There was a higher incidence of MI after PCI compared with CABG, with no difference in death or stroke. These results provide contemporary data to allow improved shared decision-making between physicians and patients with 3-vessel coronary artery disease., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02100722., Competing Interests: Disclosures Dr Pijls receives research funding from Abbott, has consulting relationships with Abbott and Opsens, and has stock or stock options with ASML, General Electric, HeartFlow, Hexacath, and Philips. Dr Mansour has consulting relationships with Abbott Vascular, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Novartis, Pfizer, and Servier Affaires, and received a research grant from Opsens Inc and Abbott Vascular. Dr Kala has a consulting relationship with Boston Scientific, Medtronic, and Servier Affaires, and receives honoraria from AstraZeneca and Bayer. Dr Angeras receives research funding from Abbott Vascular and AstraZeneca and has a consulting relationship with Abbott Vascular and Boston Scientific. Dr Miner has a consulting relationship with Abbott, Amgen, Astra Zeneca, Bayer, Boehringer, Novartis, Opsens, Pfizer, and Servier Affaires Medicales. Dr Engstrøm has a consulting relationship with Abbott Vascular, Bayer, and Novo Nordisk. Dr Christiansen has a consulting relationship with Abbott Vascular and has received research grants from Abbott Vascular. Dr Tonino has received research grants from Biosensors and Opsens. Dr Reardon has a consulting relationship with Boston Scientific and W.L. Gore & Associates. Dr Otsuki has received research grants from the Uehara Memorial Foundation, Abbott, Medtronic, Boston Scientific, and Terumo. Dr Kobayashi has a consulting relationship with Abbott Vascular. Dr Hlatky has a consulting relationship with Blue Cross and Blue Shield and research support from HeartFlow. Dr Mahaffey has received research grants or contracts from the American Heart Association, Apple, Inc, Bayer, California Institute Regenerative Medicine, Eidos, Ferring, Gilead, Google (Verily), Idorsia, Johnson & Johnson, Luitpold, PAC-12, Precordior, and Sanifit; has provided consulting or other services for Amgen, Applied Therapeutics, AstraZeneca, Bayer, CSL Behring, Elsevier, FibroGen, Inova, Johnson & Johnson, Lexicon, MyoKardia, Novartis, Novo Nordisk, Otsuka, PhaseBio, Portola, Quidel, Sanofi, and Theravance; and has equity in Precordior. Dr Yeung has a consulting relationship with Medtronic. Dr De Bruyne has an institutional consulting relationship with Boston Scientific, Abbott Vascular, CathWorks, Siemens, GE Healthcare, and Coroventis Research; receives institutional research grants from Abbott Vascular, Coroventis Research, CathWorks, and Boston Scientific; and holds minor equities in Philips, Siemens, GE Healthcare, CathWorks, Edwards Life Sciences, HeartFlow, Opsens, Celyad, Xenter, Medyria, Bayer, and Sanofi. Dr Fearon receives research funding from Abbott, Medtronic, and Boston Scientific and has a consulting relationship with Siemens and CathWorks and stock options with HeartFlow. The other authors report no conflicts of interest.

Background: Measurement of fractional flow reserve (FFR) has an established role in guiding percutaneous coronary intervention. We tested the hypothesis that, at the stage of diagnostic invasive coronary angiography, systematic FFR-guided assessment of coronary artery disease would be superior, in terms of resource use and quality of life, to assessment by angiography alone., Methods: We performed an open-label, randomized, controlled trial in 17 UK centers, recruiting 1100 patients undergoing invasive coronary angiography for the investigation of stable angina or non-ST-segment-elevation myocardial infarction. Patients were randomized to either angiography alone (angiography) or angiography with systematic pressure wire assessment of all epicardial vessels >2.25 mm in diameter (angiography+FFR). The coprimary outcomes assessed at 1 year were National Health Service hospital costs and quality of life. Prespecified secondary outcomes included clinical events., Results: In the angiography+FFR arm, the median number of vessels examined was 4 (interquartile range, 3-5). The median hospital costs were similar: angiography, £4136 (interquartile range, £2613-£7015); and angiography+FFR, £4510 (£2721-£7415; P =0.137). There was no difference in median quality of life using the visual analog scale of the EuroQol EQ-5D-5L: angiography, 75 (interquartile range, 60-87); and angiography+FFR, 75 (interquartile range, 60-90; P =0.88). The number of clinical events was as follows: deaths, 5 versus 8; strokes, 3 versus 4; myocardial infarctions, 23 versus 22; and unplanned revascularizations, 26 versus 33, with a composite hierarchical event rate of 8.7% (48 of 552) for angiography versus 9.5% (52 of 548) for angiography+FFR ( P =0.64)., Conclusions: A strategy of systematic FFR assessment compared with angiography alone did not result in a significant reduction in cost or improvement in quality of life., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT01070771.

Background: Previous studies have shown that quality of life improves after coronary revascularization more so after coronary artery bypass grafting (CABG) than after percutaneous coronary intervention (PCI). This study aimed to evaluate the effect of fractional flow reserve guidance and current generation, zotarolimus drug-eluting stents on quality of life after PCI compared with CABG., Methods: The FAME 3 trial (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) is a multicenter, international trial including 1500 patients with 3-vessel coronary artery disease who were randomly assigned to either CABG or fractional flow reserve-guided PCI. Quality of life was measured using the European Quality of Life-5 Dimensions (EQ-5D) questionnaire at baseline and 1 and 12 months. The Canadian Cardiovascular Class angina grade and working status were assessed at the same time points and at 6 months. The primary objective was to compare EQ-5D summary index at 12 months. Secondary end points included angina grade and work status., Results: The EQ-5D summary index at 12 months did not differ between the PCI and CABG groups (difference, 0.001 [95% CI, -0.016 to 0.017]; P =0.946). The trajectory of EQ-5D during the 12 months differed ( P <0.001) between PCI and CABG: at 1 month, EQ-5D was 0.063 (95% CI, 0.047 to 0.079) higher in the PCI group. A similar trajectory was found for the EQ (EuroQol) visual analogue scale. The proportion of patients with Canadian Cardiovascular Class 2 or greater angina at 12 months was 6.2% versus 3.1% (odds ratio, 2.5 [95% CI, 0.96-6.8]), respectively, in the PCI group compared with the CABG group. A greater percentage of younger patients (<65 years old) were working at 12 months in the PCI group compared with the CABG group (68% versus 57%; odds ratio, 3.9 [95% CI, 1.7-8.8])., Conclusions: In the FAME 3 trial, quality of life after fractional flow reserve-guided PCI with current generation drug-eluting stents compared with CABG was similar at 1 year. The rate of significant angina was low in both groups and not significantly different. The trajectory of improvement in quality of life was significantly better after PCI, as was working status in those <65 years old., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02100722.

Background: Measuring fractional flow reserve (FFR) with a pressure wire remains underutilized because of the invasiveness of guide wire placement or the need for a hyperemic stimulus. FFR derived from routine coronary angiography (FFR angio ) eliminates both of these requirements and displays FFR values of the entire coronary tree. The FFR angio Accuracy versus Standard FFR (FAST-FFR) study is a prospective, multicenter, international trial with the primary goal of determining the accuracy of FFR angio ., Methods: Coronary angiography was performed in a routine fashion in patients with suspected coronary artery disease. FFR was measured in vessels with coronary lesions of varying severity using a coronary pressure wire and hyperemic stimulus. Based on angiograms of the respective arteries acquired in ≥2 different projections, on-site operators blinded to FFR then calculated FFR angio using proprietary software. Coprimary end points were the sensitivity and specificity of the dichotomously scored FFR angio for predicting pressure wire-derived FFR using a cutoff value of 0.80. The study was powered to meet prespecified performance goals for sensitivity and specificity., Results: Ten centers in the United States, Europe, and Israel enrolled a total of 301 subjects and 319 vessels meeting inclusion/exclusion criteria which were included in the final analysis. The mean FFR was 0.81 and 43% of vessels had an FFR≤0.80. The per-vessel sensitivity and specificity were 94% (95% CI, 88% to 97%) and 91% (86% to 95%), respectively, both of which exceeded the prespecified performance goals. The diagnostic accuracy of FFR angio was 92% overall and remained high when only considering FFR values between 0.75 to 0.85 (87%). FFR angio values correlated well with FFR measurements ( r=0.80, P<0.001) and the Bland-Altman 95% confidence limits were between -0.14 and 0.12. The device success rate for FFR angio was 99%., Conclusions: FFR angio measured from the coronary angiogram alone has a high sensitivity, specificity, and accuracy compared with pressure wire-derived FFR. FFR angio has the promise to substantially increase physiological coronary lesion assessment in the catheterization laboratory, thereby potentially leading to improved patient outcomes., Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique Identifier: NCT03226262.

Background: Whether the benefit in quality of life (QOL) after percutaneous coronary intervention depends on the severity of the stenosis as determined by fractional flow reserve (FFR) remains unknown. This study sought to investigate the relationship between FFR values and improvement in QOL., Methods: From the FAME 1 and 2 trials (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation), we identified 706 stable patients with coronary artery disease who had at least 1 lesion with an FFR≤0.80 that was treated with percutaneous coronary intervention and 185 patients with coronary artery disease who had no lesion with an FFR≤0.80 and were treated medically who served as a reference group. QOL was assessed by the European Quality of Life-5 Dimensions index at baseline, 1 month, and 1 year. We assessed the relationship between QOL improvement (defined as the change in European Quality of Life-5 Dimensions index from baseline) and FFR as a continuous value and according to abnormal FFR tertile., Results: QOL improved significantly after percutaneous coronary intervention in each abnormal FFR tertile, whereas it did not change in the reference group. The lowest abnormal FFR subgroup had the greatest improvement in QOL at 1 month ( P<0.001). In mixed-effects models for repeated measures, lower FFR ( P=0.002 for 1 month and 0.049 for 1 year), greater delta FFR ( P=0.021 for 1 month and 0.025 for 1 year), and higher angina class ( P=0.001 for 1 month and <0.001 for 1 year) were associated with the greatest magnitude of QOL improvement at both 1 month and 1 year., Conclusions: Among patients with stable coronary artery disease, FFR and angina severity predict QOL improvement after percutaneous coronary intervention., Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT00267774 and NCT01132495.

Background: Among patients with documented stable coronary artery disease and in whom no revascularization was performed, we compared the respective values of angiographic diameter stenosis (DS) and fractional flow reserve (FFR) in predicting natural history., Methods: The present analysis included the 607 patients from the FAME 2 trial (Fractional Flow Reserve Versus Angiography in Multivessel Evaluation 2) in whom no revascularization was performed. FFR varied from 0.20 to 1.00 (average 0.74±0.16), and DS (by quantitative coronary analysis) varied from 8% to 98% (average 53±15). The primary end point, defined as vessel-oriented clinical end point (VOCE) at 2 years, was a composite of prospectively adjudicated cardiac death, vessel-related myocardial infarction, vessel-related urgent, and not urgent revascularization. The stenoses were divided into 4 groups according to FFR and %DS values: positive concordance (FFR≤0.80; DS≥50%), negative concordance (FFR>0.80; DS<50%), positive mismatch (FFR≤0.80; DS<50%), and negative mismatch (FFR>0.80; DS≥50%)., Results: The rate of VOCE was highest in the positive concordance group (log rank: X 2 =80.96; P =0.001) and lowest in the negative concordance group. The rate of VOCE was higher in the positive mismatch group than in the negative mismatch group (hazard ratio, 0.38; 95% confidence interval, 0.21-0.67; P =0.001). There was no significant difference in VOCE between the positive concordance and positive mismatch groups (FFR≤0.80; hazard ratio, 0.77; 95% confidence interval, 0.57-1.09; P =0.149) and no significant difference in rate of VOCE between the negative mismatch and negative concordance groups (FFR>0.80; hazard ratio, 1.89; 95% confidence interval, 0.96-3.74; P =0.067)., Conclusions: In patients with stable coronary disease, physiology (FFR) is a more important determinant of the natural history of coronary stenoses than anatomy (DS)., Clinical Trial Registration: URL: https://clinicaltrials.gov. Unique identifier: NCT01132495., (© 2017 American Heart Association, Inc.)

Background: Previous studies found that percutaneous coronary intervention (PCI) does not improve outcome compared with medical therapy (MT) in patients with stable coronary artery disease, but PCI was guided by angiography alone. FAME 2 trial (Fractional Flow Reserve Versus Angiography for Multivessel Evaluation) compared PCI guided by fractional flow reserve with best MT in patients with stable coronary artery disease to assess clinical outcomes and cost-effectiveness., Methods: A total of 888 patients with stable single-vessel or multivessel coronary artery disease with reduced fractional flow reserve were randomly assigned to PCI plus MT (n=447) or MT alone (n=441). Major adverse cardiac events included death, myocardial infarction, and urgent revascularization. Costs were calculated on the basis of resource use and Medicare reimbursement rates. Changes in quality-adjusted life-years were assessed with utilities determined by the European Quality of Life-5 Dimensions health survey at baseline and over follow-up., Results: Major adverse cardiac events at 3 years were significantly lower in the PCI group compared with the MT group (10.1% versus 22.0%; P <0.001), primarily as a result of a lower rate of urgent revascularization (4.3% versus 17.2%; P <0.001). Death and myocardial infarction were numerically lower in the PCI group (8.3% versus 10.4%; P =0.28). Angina was significantly less severe in the PCI group at all follow-up points to 3 years. Mean initial costs were higher in the PCI group ($9944 versus $4440; P <0.001) but by 3 years were similar between the 2 groups ($16 792 versus $16 737; P =0.94). The incremental cost-effectiveness ratio for PCI compared with MT was $17 300 per quality-adjusted life-year at 2 years and $1600 per quality-adjusted life-year at 3 years. The above findings were robust in sensitivity analyses., Conclusions: PCI of lesions with reduced fractional flow reserve improves long-term outcome and is economically attractive compared with MT alone in patients with stable coronary artery disease., Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01132495., (© 2017 American Heart Association, Inc.)

Background: The fractional flow reserve (FFR) value of 0.75 has been validated against ischemic testing, whereas the FFR value of 0.80 has been widely accepted to guide clinical decision making. However, revascularization when FFR is 0.76 to 0.80, within the so-called gray zone, is still debatable., Methods and Results: From February 1997 to June 2013, all patients with single-segment disease and an FFR value within the gray zone or within the 2 neighboring FFR strata (0.70-0.75 and 0.81-0.85) were included. Study end points consisted of major adverse cardiovascular events (death, myocardial infarction, and any revascularization) up to 5 years. Of 17 380 FFR measurements, 1459 patients were included. Of them, 449 patients were treated with revascularization and 1010 patients were treated with medical therapy. In the gray zone, the major adverse cardiovascular events rate was similar (37 [13.9%] versus 21 [11.2%], respectively; P=0.3) between medical therapy and revascularization, whereas a strong trend toward a higher rate of death or myocardial infarction (25 [9.4] versus 9 [4.8], P=0.06) and overall death (20 [7.5] versus 6 [3.2], P=0.059) was observed in the medical therapy group. Among medical therapy patients, a significant step-up increase in major adverse cardiovascular events rate was observed across the 3 FFR strata, especially with proximal lesion location. In revascularization patients, the major adverse cardiovascular events rate was not different across the 3 FFR strata., Conclusions: FFR in and around the gray zone bears a major prognostic value, especially in proximal lesions. These data confirm that FFR≤0.80 is valid to guide clinical decision making., (© 2016 American Heart Association, Inc.)

Background: Fractional flow reserve (FFR) is well established for patients undergoing percutaneous coronary intervention, yet little is known about candidates for coronary artery bypass graft surgery., Methods and Results: From 2006 to 2010, we retrospectively included in this registry 627 consecutive patients treated by coronary artery bypass graft surgery having at least 1 angiographically intermediate stenosis. In 429 patients, coronary artery bypass graft surgery was based solely on angiography (angiography-guided group). In 198 patients, at least 1 intermediate stenosis was grafted with an FFR ≤0.80 or deferred with an FFR >0.80 (FFR-guided group). The end point was major adverse cardiovascular events at 3 years, defined as the composite of overall death, myocardial infarction, and target vessel revascularization. The rate of angiographic multivessel disease was similar in the angiography-guided and FFR-guided groups (404 [94.2%] versus 186 [93.9%]; P=0.722). In the FFR-guided group, this was significantly downgraded after FFR measurements to 86.4% (P<0.001 versus before FFR) and was associated with a smaller number of anastomoses (3 [2-3] versus 3 [2-4]; P<0.001) and rate of on-pump surgery (49% versus 69%; P<0.001). At 3 years, major adverse cardiovascular events were not different between the angiography-guided and FFR-guided groups (12% versus 11%; hazard ratio, 1.030; 95% confidence interval, 0.627-1.692; P=0.908). However, the FFR-guided group compared with the angiography-guided group presented a significantly lower rate of angina (Canadian Cardiovascular Society class II-IV, 31% versus 47%; P<0.001)., Conclusions: FFR-guided coronary artery bypass graft surgery was associated with a lower number of graft anastomoses and a lower rate of on-pump surgery compared with angiography-guided coronary artery bypass graft surgery. This did not result in a higher event rate during up to 36 months of follow-up and was associated with a lower rate of angina.

With advances in technology, the physiological assessment of coronary artery disease in patients in the catheterization laboratory has become increasingly important in both clinical and research applications, but this assessment has evolved without standard nomenclature or techniques of data acquisition and measurement. Some questions regarding the interpretation, application, and outcome related to the results also remain unanswered. Accordingly, this consensus statement was designed to provide the background and evidence about physiological measurements and to describe standard methods for data acquisition and interpretation. The most common uses and support data from numerous clinical studies for the physiological assessment of coronary artery disease in the cardiac catheterization laboratory are reviewed. The goal of this statement is to provide a logical approach to the use of coronary physiological measurements in the catheterization lab to assist both clinicians and investigators in improving patient care.

Background: Adrenergic regulation of coronary vasomotion is balanced between alpha1-adrenergic-mediated (alpha1-AR) constriction and beta2-adrenergic-mediated (beta2-AR) relaxation. This study aimed at assessing the role of beta2-ARs in normal, mildly atherosclerotic, and stenotic human coronary arteries., Methods and Results: During intracoronary (IC) infusion of increasing doses of the beta2-AR agonist salbutamol (0.15, 0.3, and 0.6 mug/min) and the endothelial vasodilator acetylcholine (1, 3, and 10 microg/min), we measured (1) changes in lumen diameter (LD) by quantitative coronary angiography in 34 normal, 55 mildly atherosclerotic, and 42 stenotic coronary artery segments and (2) changes in average peak velocity (APV) and coronary blood flow (CBF) with the use of Doppler flow wire in 11 normal, 10 mildly atherosclerotic, and 11 stenotic coronary arteries. In 6 of 11 stenotic coronary arteries, the protocol was repeated after an IC bolus (12 microg/kg) of the alpha-adrenergic blocker phentolamine. In 6 of 11 normal coronary arteries, the protocol was repeated after an IC infusion (60 micromol/min) of N(G)-monomethyl-L-arginine (L-NMMA), a nitric oxide inhibitor. Neither salbutamol IC infusion nor acetylcholine significantly changed heart rate or blood pressure, whereas L-NMMA slightly increased blood pressure. In normal coronary arteries, salbutamol increased LD (LD max %: 11+/-2, P<0.05), APV (APV max %: 53+/-17, P<0.05), and CBF (CBF max %: 57+/-17, P<0.05), whereas L-NMMA caused a blunted APV (APV max %: 27+/-6, P<0.05) and CBF (CBF max %: 29+/-6, P<0.05) response to salbutamol. In mildly atherosclerotic coronary arteries, the salbutamol increase in LD (LD max %: 10+/-2, P<0.05), APV (APV max %: 33+/-12, P<0.05), and CBF (CBF max %: 37+/-12, P<0.05) was preserved. In stenotic coronary arteries, salbutamol induced a paradoxical reduction in LD (LD max %: -6+/-2, P<0.05), APV (APV max %: -15+/-9, P<0.05), and CBF (CBF max %: -15+/-6, P<0.05), which was no longer observed after phentolamine. Acetylcholine increased LD (LD max %: 14+/-3, P<0.05), APV (APV max %: 61+/-20, P<0.05), and CBF (CBF max %: 67+/-19, P<0.05) in normal coronary arteries. In mildly atherosclerotic coronary arteries, acetylcholine induced a significant reduction in LD (LD max %: -15+/-2, P<0.05) and no changes in APV (APV max %: -6+/-13, P=NS) and CBF (CBF max %: -10+/-13, P=NS). In stenotic coronary arteries, acetylcholine significantly reduced LD (LD max %: -15+/-3, P<0.05), APV (APV max %: -15+/-9, P<0.05), and CBF (CBF max %: -15+/-6, P<0.05)., Conclusions: In severely atherosclerotic coronary arteries, beta2-adrenergic vasodilatation is impaired, and this might contribute to alter the vasomotor balance, further precipitating myocardial ischemia during sympathetic activation.

Background: The effect of epicardial artery stenosis on myocardial microvascular resistance remains controversial. Recruitable collateral flow, which may affect resistance, was not incorporated into previous measurements., Methods and Results: In an open-chest pig model, distal coronary pressure was measured with a pressure wire, and the apparent minimal microvascular resistance was calculated during peak hyperemia as pressure divided by flow, measured either with a flow probe around the coronary artery (R(micro app)) or with a novel thermodilution technique (apparent index of microcirculatory resistance [IMR(app)]). These apparent resistances were compared with the actual R(micro) and IMR after the coronary wedge pressure and collateral flow were incorporated into the calculation. Measurements were made at baseline (no stenosis) and after creation of moderate and severe epicardial artery stenoses. In 6 pigs, 189 measurements of R(micro) and IMR were made under the various epicardial artery conditions. Without consideration of collateral flow, R(micro app) (0.43+/-0.12 to 0.46+/-0.10 to 0.51+/-0.11 mm Hg/mL per minute) and IMR(app) (14+/-4 to 17+/-7 to 20+/-10 U) increased progressively and significantly with increasing epicardial artery stenosis (P<0.001 for both). With the incorporation of collateral flow, neither R(micro) nor IMR increased as a result of increasing epicardial artery stenosis., Conclusions: After collateral flow is taken into account, the minimum achievable microvascular resistance is not affected by increasing epicardial artery stenosis.

Background: Cardiac resynchronization therapy was shown to reverse left ventricular (LV) remodeling in patients with congestive heart failure (CHF). However, the prediction of benefit is controversial. We aimed to investigate predictive factors of LV functional recovery and reversed remodeling after biventricular pacing., Methods and Results: Forty-nine consecutive patients with CHF and a wide QRS complex (182+/-32 ms) were studied by echocardiography before resynchronization. Intraventricular and interventricular asynchrony and their combination were assessed by pulsed-wave tissue Doppler imaging from measurements of regional electromechanical coupling times in basal segments of the right and left ventricle. At 6-month follow-up, responders were defined by a relative increase in LV ejection fraction > or =25% compared with baseline (n=27). Receiver operating curve analysis revealed the degree of intraventricular asynchrony (area under the curve=0.77), interventricular asynchrony (area under the curve=0.69), and their combination (area under the curve=0.84) as the best predictors of functional recovery after resynchronization. In addition, the degree of intraventricular and interventricular asynchrony correlated significantly with the improvement of LV ejection fraction (r=0.73, P<0.0001), end-diastolic diameter (r=-0.59, P<0.0001), and end-systolic diameter (r=-0.48, P<0.001) at follow-up. QRS duration and conventional echo-Doppler indices were not predictive of reversed LV remodeling., Conclusions: In patients with CHF, the degree of intraventricular and interventricular asynchrony and their combination are the best predictive factors of LV functional recovery and reversed remodeling after cardiac resynchronization therapy.

Background: Inducing both maximal and steady-state coronary hyperemia is of clinical importance to take full advantage of fractional flow reserve measurements. The present study compares different dosages and routes of administration of adenosine 5'-triphosphate (ATP), adenosine, contrast medium, and papaverine regarding their potential to achieve both maximal and steady-state hyperemia., Methods and Results: In 21 patients with an isolated coronary stenosis, coronary vasodilation was induced successively by papaverine (20 mg intracoronary), adenosine (20 and 40 microg intracoronary), ATP (20 and 40 microg intracoronary), iohexol (6 mL intracoronary), adenosine or ATP through an antecubital vein (140 and 180 microg x kg(-1) x min(-1)), or adenosine or ATP through a femoral vein (140 and 180 microg x kg(-1) x min(-1)). Because vessel dimensions did not change, the ratio of distal coronary pressure (Pd) to aortic pressure (Pa) was used as an index of myocardial resistance. Pd/Pa was 0.77+/-0.21 at rest and decreased to 0.61+/-0.21 after papaverine. Pd/Pa decreased to a similar level with all other vasodilators, except with contrast medium (0.68+/-0.21; P<0.01 versus papaverine). Steady-state hyperemia could only be obtained by intracoronary papaverine and by intravenous ATP or adenosine. In another 23 patients, an intravenous infusion of ATP was varied from 0 to 280 microg x kg(-1) x min(-1). At doses >140 microg x kg(-1) x min(-1), there was neither a further decrease in Pd/Pa ratio nor a further increase in coronary flow velocities., Conclusions: Provided sufficient dosages are used, ATP, adenosine, and papaverine (but not contrast medium) induce maximal hyperemia and are therefore suitable to assess fractional flow reserve. Only intracoronary papaverine and intravenous ATP or adenosine induce steady-state hyperemia enabling a pressure pullback maneuver that is useful in assessing diffuse coronary atherosclerosis.

Background: Coronary stenting is associated with a restenosis rate of 15% to 20% at 6-month follow-up, despite optimum angiographic stent implantation. In this multicenter registry, we investigated the relation between optimum physiological stent implantation as assessed by poststent fractional flow reserve (FFR) and outcome at 6 months., Methods and Results: In 750 patients, coronary pressure measurement at maximum hyperemia was performed after angiographically apparently satisfactory stent implantation. Poststenting FFR was calculated and related to major adverse events (including need for repeat target vessel revascularization) at 6 months. In 76 patients (10.2%), at least 1 adverse event occurred. Five patients died, 19 experienced myocardial infarction, and 52 underwent at least 1 repeat target vessel revascularization. By multivariate analysis, FFR immediately after stenting was the most significant independent variable related to all types of events. In 36% of the patients, FFR normalized (>0.95), and event rate was 4.9% in that group. In 32% of the patients, poststent FFR was between 0.90 and 0.95, and event rate was 6.2%. In 32% of patients, poststent FFR was <0.90, and event rate was 20.3%. In 6% of the patients, FFR was <0.80, and event rate was 29.5% (P<0.001)., Conclusions: FFR after stenting is a strong independent predictor of outcome at 6 months.

Background: Guide wire-based simultaneous measurement of fractional flow reserve (FFR) and coronary flow reserve (CFR) is important to understand microvascular disease of the heart. The aim of this study was to investigate the feasibility of simultaneous measurement of FFR and CFR by one pressure-temperature sensor-tipped guide wire with the use of coronary thermodilution and to compare CFR by thermodilution (CFR(thermo)) with simultaneously measured Doppler CFR (CFR(Doppl))., Methods and Results: In 103 coronary arteries in 50 patients, a pressure-temperature sensor-tipped 0.014-inch floppy guide wire and a 0.014-inch Doppler guide wire were introduced. Both normal vessels and a wide range of stenotic vessels were included. With 3 mL of saline at room temperature used as an indicator, by hand-injection, thermodilution curves in the coronary artery were obtained in triplicate, both at baseline and at intravenous adenosine-induced maximum hyperemia. After adequate curve-fitting, CFR(thermo) was calculated from the ratio of inverse mean transit times and compared with CFR(Doppl) calculated by velocities at hyperemia and baseline. Adequate sets of thermodilution curves and corresponding CFR(thermo) could be obtained in 87% of the arteries versus 91% for Doppler CFR and 100% for FFR. CFR(thermo) correlated fairly well to CFR(Doppl) (CFR(thermo)=0.84 CFR(Doppl)+0.17; r=0.80; P<0.001), although individual differences of >20% between both indexes were seen in a quarter of all arteries., Conclusions: This study shows the feasibility of simultaneous measurement of FFR (by coronary pressure) and CFR (by coronary thermodilution) in humans by one single guide wire in a practical and straightforward way and will facilitate assessment of microvascular disease.

Background: Coronary arteries without focal stenosis at angiography are generally considered non-flow-limiting. However, atherosclerosis is a diffuse process that often remains invisible at angiography. Accordingly, we hypothesized that in patients with coronary artery disease, nonstenotic coronary arteries induce a decrease in pressure along their length due to diffuse coronary atherosclerosis., Methods and Results: Coronary pressure and fractional flow reserve (FFR), as indices of coronary conductance, were obtained from 37 arteries in 10 individuals without atherosclerosis (group I) and from 106 nonstenotic arteries in 62 patients with arteriographic stenoses in another coronary artery (group II). In group I, the pressure gradient between aorta and distal coronary artery was minimal at rest (1+/-1 mm Hg) and during maximal hyperemia (3+/-3 mm Hg). Corresponding values were significantly larger in group II (5+/-4 mm Hg and 10+/-8 mm Hg, respectively; both P<0.001). The FFR was near unity (0.97+/-0.02; range, 0.92 to 1) in group I, indicating no resistance to flow in truly normal coronary arteries, but it was significantly lower (0.89+/-0.08; range, 0.69 to 1) in group II, indicating a higher resistance to flow. In 57% of arteries in group II, FFR was lower than the lowest value in group I. In 8% of arteries in group II, FFR was <0.75, the threshold for inducible ischemia., Conclusion: Diffuse coronary atherosclerosis without focal stenosis at angiography causes a graded, continuous pressure fall along arterial length. This resistance to flow contributes to myocardial ischemia and has consequences for decision-making during percutaneous coronary interventions.

Background: Lesions in small-diameter vessels (<3 mm) define a group with distinct clinical and morphological characteristics. There is an inverse relationship between vessel size and angiographic restenosis rate. This study assessed whether stents reduce angiographic restenosis in small coronary arteries compared with standard balloon angioplasty., Methods and Results: We randomly assigned 351 symptomatic patients needing dilatation of 1 native coronary vessel between 2.3 and 2.9 mm in size to angioplasty alone (n=182) or stent implantation (n=169). The primary end point was angiographic restenosis at 6 months. Secondary end points included death, myocardial infarction, bypass surgery, and target vessel revascularization in hospital and at 6 months. There were no significant differences between groups in terms of major in-hospital complications. There was a trend toward fewer in-hospital events in the stent group (3% versus 7.1% in angioplasty group, P=0.076). Crossovers to stent occurred in 37 patients (20.3%). Repeat angiography at 6-month follow-up was performed in 85.3% of patients. Angiographic restenosis occurred in 28% of the stent group and 32.9% of the angioplasty group (P=0.36). Target vessel revascularization was required in 17.8% versus 20.3% of patients (P=0.54), respectively., Conclusions: Stenting and standard coronary angioplasty are associated with equal restenosis rate in small coronary arteries. With a lower in-hospital complication rate, stenting may be a superior strategy in small vessels.

Background: Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive., Methods and Results: To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is "optimal." An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P:=0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P:=0. 066)., Conclusions: After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.