Interaction of AI-Enabled Quantitative Coronary Plaque Volumes on Coronary CT Angiography, FFRCT, and Clinical Outcomes: A Retrospective Analysis of the ADVANCE Registry.

BACKGROUND: Luminal stenosis, computed tomography-derived fractional-flow reserve (FFRCT), and high-risk plaque features on coronary computed tomography angiography are all known to be associated with adverse clinical outcomes. The interactions between these variables, patient outcomes, and quantitative plaque volumes have not been previously described. METHODS: Patients with coronary computed tomography angiography (n=4430) and one-year outcome data from the international ADVANCE (Assessing Diagnostic Value of Noninvasive FFRCT in Coronary Care) registry underwent artificial intelligence-enabled quantitative coronary plaque analysis. Optimal cutoffs for coronary total plaque volume and each plaque subtype were derived using receiver-operator characteristic curve analysis. The resulting plaque volumes were adjusted for age, sex, hypertension, smoking status, type 2 diabetes, hyperlipidemia, luminal stenosis, distal FFRCT, and translesional delta-FFRCT. Median plaque volumes and optimal cutoffs for these adjusted variables were compared with major adverse cardiac events, late revascularization, a composite of the two, and cardiovascular death and myocardial infarction. RESULTS: At one year, 55 patients (1.2%) had experienced major adverse cardiac events, and 123 (2.8%) had undergone late revascularization (>90 days). Following adjustment for age, sex, risk factors, stenosis, and FFRCT, total plaque volume above the receiver-operator characteristic curve-derived optimal cutoff (total plaque volume >564 mm3) was associated with the major adverse cardiac event/late revascularization composite (adjusted hazard ratio, 1.515 [95% CI, 1.093-2.099]; P=0.0126), and both components. Total percent atheroma volume greater than the optimal cutoff was associated with both major adverse cardiac event/late revascularization (total percent atheroma volume >24.4%; hazard ratio, 2.046 [95% CI, 1.474-2.839]; P<0.0001) and cardiovascular death/myocardial infarction (total percent atheroma volume >37.17%, hazard ratio, 4.53 [95% CI, 1.943-10.576]; P=0.0005). Calcified, noncalcified, and low-attenuation percentage atheroma volumes above the optimal cutoff were associated with all adverse outcomes, although this relationship was not maintained for cardiovascular death/myocardial infarction in analyses stratified by median plaque volumes. CONCLUSIONS: Analysis of the ADVANCE registry using artificial intelligence-enabled quantitative plaque analysis shows that total plaque volume is associated with one-year adverse clinical events, with incremental predictive value over luminal stenosis or abnormal physiology by FFRCT. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02499679.

Preoperative angiography-derived fractional flow reserve may predict coronary artery bypass grafting occlusion and disease progression.

BACKGROUND: Graft occlusion after coronary artery bypass grafting (CABG) has been associated with competitive flow of native coronary arteries. OBJECTIVES: To assess with coronary computed tomography angiography (CCTA) graft occlusion and coronary artery disease (CAD) progression of native vessels after CABG and their relationship with angiography-derived vessel fractional flow reserve (vFFR) performed before surgery. METHODS: Between 2006 and 2018, serial vFFR analyses were obtained before CABG in each major native coronary vessel from two institutions. All patients underwent follow-up CCTA. RESULTS: In 171 consecutive patients, serial preoperative angiograms were suitable for vFFR analysis of 298 grafted and 59 nongrafted vessels. Median time between CABG and CCTA was 2.1 years. Preoperative vFFR was assessed in 131 left anterior descending artery (LAD), 132 left circumflex artery (LCX) and 94 right coronary aretry (RCA) and was less than 0.80 in 255 of 298 bypassed vessels. Graft occlusion was observed at CCTA in 28 of 298 grafts. The median preoperative vFFR value of native coronaries was higher in occluded compared with patent grafts (0.75 vs. 0.60, P < 0.001) and was associated with graft. The best vFFR cut-off to predict graft occlusion was 0.67. Progression of CAD was higher in grafted than in nongrafted vessels (89.6 vs. 47.5%, P < 0.001). Pre-CABG vFFR predicted disease progression of grafted native vessels (AUC = 0.83). CONCLUSION: Preoperative vFFR derived from invasive coronary angiography was able to predict graft occlusion and CAD progression of grafted coronary arteries.

Fractional Flow Reserve-Guided PCI or Coronary Bypass Surgery for 3-Vessel Coronary Artery Disease: 3-Year Follow-Up of the FAME 3 Trial.

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.

Effects of ticagrelor and prasugrel on coronary microcirculation in elective percutaneous coronary intervention.

OBJECTIVE: To compare the effects of ticagrelor and prasugrel on absolute coronary blood flow (Q) and microvascular resistance (R) in patients with stable coronary artery disease (CAD) treated with elective percutaneous coronary intervention (PCI) (NCT05643586). Besides being at least as effective as prasugrel in inhibiting platelet aggregation, ticagrelor has been shown to have additional properties potentially affecting coronary microcirculation. METHODS: We randomly assigned 50 patients to ticagrelor (180 mg) or prasugrel (60 mg) at least 12 hours before intervention. Continuous thermodilution was used to measure Q and R before and after PCI. Platelet reactivity was measured before PCI. Troponin I was measured before, 8 and 24 hours after PCI. RESULTS: At baseline, fractional flow reserve, Q and R were similar in two study groups. Patients in the ticagrelor group showed higher post-PCI Q (242±49 vs 205±53 mL/min, p=0.015) and lower R values (311 (263, 366) vs 362 (319, 382) mm Hg/L/min, p=0.032). Platelet reactivity showed a negative correlation with periprocedural variation of Q values (r=-0.582, p<0.001) and a positive correlation with periprocedural variation of R values (r=0.645, p<0.001). The periprocedural increase in high-sensitivity troponin I was significantly lower in the ticagrelor compared with the prasugrel group (5 (4, 9) ng/mL vs 14 (10, 24) ng/mL, p<0.001). CONCLUSIONS: In patients with stable CAD undergoing PCI, pretreatment with a loading dose of ticagrelor compared with prasugrel improves post-procedural coronary flow and microvascular function and seems to reduce the related myocardial injury.

Safety of Right and Left Ventricular Endomyocardial Biopsy in Heart Transplantation and Cardiomyopathy Patients.

BACKGROUND: Endomyocardial biopsy (EMB) facilitates a histopathologic diagnosis with unique prognostic and therapeutic implications in both native and donor hearts. It is a relatively safe procedure, with an overall complication rate ranging from <1% to 6% depending on the experience of the operator, the clinical status of the patient, the presence or absence of left bundle branch block, the access site, and the site of procurement (right ventricular [RV] vs left ventricular [LV] approach). OBJECTIVES: This study aimed to assess the incidence of procedure-related complications in a real-world population. EMBs were performed either for surveillance of rejection episodes after heart transplantation or for diagnosis of etiology of cardiomyopathy. METHODS: The authors retrospectively analyzed 1,368 biopsies obtained in 561 consecutive patients between May 2011 and May 2021. Patients were stratified according to the underlying heart disease, sex, age, access site, body mass index, and RV vs LV approach. RESULTS: The analysis revealed an overall complication rate of 4.1%. Serious life-threatening cardiac complications occurred in <1% of EMBs, with tamponade necessitating pericardiocentesis in 0.2% and urgent cardiac surgery in 0.1% of the procedures. Minor complications occurred in 3.3% of the overall population and were more often encountered during LV EMBs (3.9%) and when the native heart was sampled (5.3%). CONCLUSIONS: In experienced hands, LV and RV EMB for heart transplantation rejection surveillance and cardiomyopathy diagnosis is a safe procedure with low risk of complications. Older, female patients and those undergoing native heart EMB were more prone to complications following EMB.

Saline-induced coronary hyperemia with continuous intracoronary thermodilution is mediated by intravascular hemolysis.

BACKGROUND AND AIMS: Absolute coronary flow can be measured by intracoronary continuous thermodilution of saline through a dedicated infusion catheter (RayFlow®). A saline infusion rate at 15-20 mL/min induces an immediate, steady-state, maximal microvascular vasodilation. The mechanism of this hyperemic response remains unclear. We aimed to test whether local hemolysis is a potential mechanism of saline-induced coronary hyperemia. METHODS: Twelve patients undergoing left and right catheterization were included. The left coronary artery and the coronary sinus were selectively cannulated. Absolute resting and hyperemic coronary flow were measured by continuous intracoronary thermodilution. Arterial and venous samples were collected from the coronary artery and the coronary sinus in five phases: baseline (BL); resting flow measurement (Rest, saline infusion at 10 mL/min); hyperemia (Hyperemia, saline infusion at 20 mL/min); post-hyperemia (Post-Hyperemia, 2 min after the cessation of saline infusion); and control phase (Control, during infusion of saline through the guide catheter at 30 mL/min). RESULTS: Hemolysis was visually detected only in the centrifugated venous blood samples collected during the Hyperemia phase. As compared to Rest, during Hyperemia both LDH (131.50 ± 21.89 U/dL [Rest] and 258.33 ± 57.40 U/dL [Hyperemia], p < 0.001) and plasma free hemoglobin (PFHb, 4.92 ± 3.82 mg/dL [Rest] and 108.42 ± 46.58 mg/dL [Hyperemia], p < 0.001) significantly increased in the coronary sinus. The percentage of hemolysis was significantly higher during the Hyperemia phase (0.04 ± 0.02% [Rest] vs 0.89 ± 0.34% [Hyperemia], p < 0.001). CONCLUSIONS: Saline-induced hyperemia through a dedicated intracoronary infusion catheter is associated with hemolysis. Vasodilatory compounds released locally, like ATP, are likely ultimately responsible for localized microvascular vasodilation.

First report of totally robotically assisted hybrid coronary artery revascularization combining RE-MIDCAB and R-PCI: Case report.

A 62-year-old man presents to the Cardiology Department with a history of angina on exertion. Invasive coronary angiography revealed a severe three vessels coronary artery disease. The "Hybrid Heart Team" successfully performed a fully robotically assisted hybrid revascularization combining robotically enhanced-minimally invasive direct coronary artery bypass on the left anterior descending (LAD) and robotically assisted percutaneous coronary intervention on non-LAD lesions.

Quality of Life After Fractional Flow Reserve-Guided PCI Compared With Coronary Bypass Surgery.

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.

Fractional Flow Reserve-Guided PCI as Compared with Coronary Bypass Surgery.

BACKGROUND: Patients with three-vessel coronary artery disease have been found to have better outcomes with coronary-artery bypass grafting (CABG) than with percutaneous coronary intervention (PCI), but studies in which PCI is guided by measurement of fractional flow reserve (FFR) have been lacking. METHODS: In this multicenter, international, noninferiority trial, patients with three-vessel coronary artery disease were randomly assigned to undergo CABG or FFR-guided PCI with current-generation zotarolimus-eluting stents. The primary end point was the occurrence within 1 year of a major adverse cardiac or cerebrovascular event, defined as death from any cause, myocardial infarction, stroke, or repeat revascularization. Noninferiority of FFR-guided PCI to CABG was prespecified as an upper boundary of less than 1.65 for the 95% confidence interval of the hazard ratio. Secondary end points included a composite of death, myocardial infarction, or stroke; safety was also assessed. RESULTS: A total of 1500 patients underwent randomization at 48 centers. Patients assigned to undergo PCI received a mean (±SD) of 3.7±1.9 stents, and those assigned to undergo CABG received 3.4±1.0 distal anastomoses. The 1-year incidence of the composite primary end point was 10.6% among patients randomly assigned to undergo FFR-guided PCI and 6.9% among those assigned to undergo CABG (hazard ratio, 1.5; 95% confidence interval [CI], 1.1 to 2.2), findings that were not consistent with noninferiority of FFR-guided PCI (P = 0.35 for noninferiority). The incidence of death, myocardial infarction, or stroke was 7.3% in the FFR-guided PCI group and 5.2% in the CABG group (hazard ratio, 1.4; 95% CI, 0.9 to 2.1). The incidences of major bleeding, arrhythmia, and acute kidney injury were higher in the CABG group than in the FFR-guided PCI group. CONCLUSIONS: In patients with three-vessel coronary artery disease, FFR-guided PCI was not found to be noninferior to CABG with respect to the incidence of a composite of death, myocardial infarction, stroke, or repeat revascularization at 1 year. (Funded by Medtronic and Abbott Vascular; FAME 3 ClinicalTrials.gov number, NCT02100722.).

Influence of fractional flow reserve on grafts patency: Systematic review and patient-level meta-analysis.

OBJECTIVE: To investigate the impact of invasive functional guidance for coronary artery bypass graft surgery (CABG) on graft failure. BACKGROUND: Data on the impact of fractional flow reserve (FFR) in guiding CABG are still limited. METHODS: Systematic review and individual patient data meta-analysis were performed. Primary objective was the risk of graft failure, stratified by FFR. Risk estimates are reported as odds ratios (ORs) derived from the aggregated data using random-effects models. Individual patient data were analyzed using mixed effect model to assess relationship between FFR and graft failure. This meta-analysis is registered in PROSPERO (CRD42020180444). RESULTS: Four prospective studies comprising 503 patients referred for CABG, with 1471 coronaries, assessed by FFR were included. Graft status was available for 1039 conduits at median of 12.0 [IQR 6.6; 12.0] months. Risk of graft failure was higher in vessels with preserved FFR (OR 5.74, 95% CI 1.71-19.29). Every 0.10 FFR units decrease in the coronaries was associated with 56% risk reduction of graft failure (OR 0.44, 95% CI 0.34 to 0.59). FFR cut-off to predict graft failure was 0.79. CONCLUSION: Surgical grafting of coronaries with functionally nonsignificant stenoses was associated with higher risk of graft failure.

Microvascular Resistance Reserve for Assessment of Coronary Microvascular Function: JACC Technology Corner.

The need for a quantitative and operator-independent assessment of coronary microvascular function is increasingly recognized. We propose the theoretical framework of microvascular resistance reserve (MRR) as an index specific for the microvasculature, independent of autoregulation and myocardial mass, and based on operator-independent measurements of absolute values of coronary flow and pressure. In its general form, MRR equals coronary flow reserve (CFR) divided by fractional flow reserve (FFR) corrected for driving pressures. In 30 arteries, pressure, temperature, and flow velocity measurements were obtained simultaneously at baseline (BL), during infusion of saline at 10 mL/min (rest) and 20 mL/min (hyperemia). A strong correlation was found between continuous thermodilution-derived MRR and Doppler MRR (r = 0.88; 95% confidence interval: 0.72-0.93; P < 0.001). MRR was independent from the epicardial resistance, the lower the FFR value, the greater the difference between MRR and CFR. Therefore, MRR is proposed as a specific, quantitative, and operator-independent metric to quantify coronary microvascular dysfunction.

Simplified Assessment of the Index of Microvascular Resistance.

BACKGROUND: To validate a simplified invasive method for the calculation of the index of microvascular resistance (IMR). METHODS: This is a prospective, single-center study of patients with chronic coronary syndromes presenting with nonobstructive coronary artery disease. IMR was obtained using both intravenous (IV) adenosine and intracoronary (IC) papaverine. Each IMR measurement was obtained in duplicate. The primary objective was the agreement between IMR acquired using adenosine and papaverine. Secondary objectives include reproducibility of IMR and time required for the IMR measurement. RESULTS: One hundred and sixteen IMR measurements were performed in 29 patients. The mean age was 68.8 ± 7.24 years, and 27.6% was diabetics. IMR values were similar between papaverine and adenosine (17.7 ± 7.26 and 20.1 ± 8.6, p=0.25; Passing-Bablok coefficient A 0.58, 95% CI -2.42 to 3.53; coefficient B 0.90, 95% CI -0.74 to 1.07). The reproducibility of IMR was excellent with both adenosine and papaverine (ICC 0.78, 95% CI 0.63 to 0.88 and ICC 0.93, 95% CI 0.87 to 0.97). The time needed for microvascular assessment was significantly shortened by the use of IC papaverine (3.23 (2.84, 3.78) mins vs. 5.48 (4.94, 7.09) mins, p < 0.0001). CONCLUSION: IMR can be reliably measured using IC papaverine with similar results compared to intravenous infusion of adenosine with increased reproducibility and reduced procedural time. This approach simplifies the invasive assessment of the coronary microcirculation in the catheterization laboratory.

Changes in surgical revascularization strategy after fractional flow reserve.

AIMS: In the randomized GRAFFITI trial, surgeons drew their strategy based on coronary angiography. When patients were randomized to fractional flow reserve (FFR)-guidance, surgeons were informed of the FFR values and asked to redraw their strategy. The aim of this study was to investigate the changes induced by FFR knowledge. METHODS AND RESULTS: The intended and performed strategy (before and after FFR) were compared. Among 172 patients, 84 with 300 lesions were randomized to the FFR-guided group. The intended strategy was to bypass 236 stenoses:108 with a venous and 128 with an arterial graft. After disclosing FFR, a change in strategy occurred in 64 lesions (21.3%) of 48 (55%) patients. Among 64 lesions for which the intended strategy was medical therapy, 16 (25%) were bypassed after disclosing FFR. The number of procedures with >1 venous graft planned was significantly reduced from 37 to 27 patients (p = .031). The proportion of on-pump surgery was significantly reduced from 71 to 61 patients (p = .006). The rates of clinical events at 1 year were similar between patients with or without at least one change in strategy. DISCUSSION: FFR-guided CABG is associated with a simplified surgical procedure in 55% of the patients, with similar clinical outcomes.

Coronary Artery Bypass Grafting or Fractional Flow Reserve-Guided Percutaneous Coronary Intervention in Diabetic Patients With Multivessel Disease.

BACKGROUND: In diabetic patients with multivessel coronary artery disease, coronary artery bypass grafting (CABG) has shown long-term benefits over percutaneous coronary intervention (PCI). Physiology-guided PCI has shown to improve clinical outcomes in multivessel coronary artery disease, though its impact in diabetic patients has never been investigated. We evaluated long-term clinical outcomes of diabetic patients with multivessel coronary artery disease treated with fractional flow reserve (FFR)-guided PCI compared with CABG. METHODS: From 2010 to 2018, 4622 diabetic patients undergoing coronary angiography were screened for inclusion. The inclusion criterion was the presence of at least 2-vessel disease defined as with diameter stenosis ≥50%, in which at least 1 intermediate stenosis (diameter stenosis, 30%-70%) was treated or deferred according to FFR. Inverse probability of treatment weighting analysis was used to account for baseline differences with a contemporary cohort of patients treated with CABG. The primary end point was major adverse cardiovascular and cerebrovascular events, defined as all-cause death, myocardial infarction, revascularization, or stroke. RESULTS: A total of 418 patients were included in the analysis. Among them, 209 patients underwent CABG and 209 FFR-guided PCI. At 5 years, the incidence of major adverse cardiovascular and cerebrovascular events was higher in the FFR-guided PCI versus the CABG group (44.5% versus 31.9%; hazard ratio, 1.60 [95% CI, 1.15-2.22]; P=0.005). No difference was found in the composite of all-cause death, myocardial infarction, or stroke (28.8% versus 27.5%; hazard ratio, 1.05 [95% CI, 0.72-1.53]; P=0.81). Repeat revascularization was more frequent with FFR-guided PCI (24.9% versus 8.2%; hazard ratio, 3.51 [95% CI, 1.93-6.40]; P<0.001). CONCLUSIONS: In diabetic patients with multivessel coronary artery disease, CABG was associated with a lower rate of major adverse cardiovascular and cerebrovascular events compared with FFR-guided PCI, driven by a higher rate of repeat revascularization. At 5-year follow-up, no difference was observed in the composite of all-cause death, myocardial infarction, or stroke between CABG and FFR-guided PCI. Graphic Abstract: A graphic abstract is available for this article.

Intracoronary Saline-Induced Hyperemia During Coronary Thermodilution Measurements of Absolute Coronary Blood Flow: An Animal Mechanistic Study.

Background Absolute hyperemic coronary blood flow and microvascular resistances can be measured by continuous thermodilution with a dedicated infusion catheter. We aimed to determine the mechanisms of this hyperemic response in animal. Methods and Results Twenty open chest pigs were instrumented with flow probes on coronary arteries. The following possible mechanisms of saline-induced hyperemia were explored compared with maximal hyperemia achieve with adenosine by testing: (1) various infusion rates; (2) various infusion content and temperature; (3) NO production inhibition with L-arginine methyl ester and endothelial denudation; (4) effects of vibrations generated by rotational atherectomy and of infusion through one end-hole versus side-holes. Saline infusion rates of 5, 10 and 15 mL/min did not reach maximal hyperemia as compared with adenosine. Percentage of coronary blood flow expressed in percent of the coronary blood flow after adenosine were 48±17% at baseline, 57±18% at 5 mL/min, 65±17% at 10 mL/min, 82±26% at 15 mL/min and 107±18% at 20 mL/min. Maximal hyperemia was observed during infusion of both saline at body temperature and glucose 5%, after endothelial denudation, l-arginine methyl ester administration, and after stent implantation. The activation of a Rota burr in the first millimeters of the epicardial artery also induced maximal hyperemia. Maximal hyperemia was achieved by infusion through lateral side-holes but not through an end-hole catheter. Conclusions Infusion of saline at 20 mL/min through a catheter with side holes in the first millimeters of the epicardial artery induces maximal hyperemia. The data indicate that this vasodilation is related neither to the composition/temperature of the indicator nor is it endothelial mediated. It is suggested that it could be elicited by epicardial wall vibrations.

Graft patency and progression of coronary artery disease after CABG assessed by angiography-derived fractional flow reserve.

BACKGROUND: Graft occlusion after coronary artery bypass graft surgery (CABG) has been associated with native coronary artery competitive flow. OBJECTIVES: The present study aims to characterize the functional progression of coronary artery disease (CAD) in native vessels after CABG, and to assess the relationship between preoperative FFR as derived from angiography and graft occlusion. METHODS: Multicenter study of consecutive patients undergoing CABG between 2013 and 2018, in whom a follow-up angiogram had been performed. Serial vessel-fractional flow reserve (vFFR) analyses were obtained in each major native coronary vessel before and after CABG, excluding post-anastomotic segments and graft conduits. RESULTS: In 73 patients, serial angiograms were suitable for vFFR analysis, including 118 grafted (86 arterial and 32 saphenous grafts) and 64 non-grafted vessels. The median time between CABG and follow-up angiography was 2.4 years [IQR 1.5, 3.3]. Functional CAD progression, by means of decline in vFFR, was observed in grafted but not in non-grafted vessels (delta vFFR in grafted vessels 0.10 [IQR 0.05, 0.18] vs. 0.01 [IQR -0.01, 0.03], in non-grafted vessels, p < 0.001). Preoperative vFFR predicted graft occlusion (AUC: 0.66, 95% CI 0.52 to 0.80, p = 0.031). CONCLUSIONS: In patients undergoing CABG, preoperative vFFR derived from conventional angiograms without use of pressure wire was able to predict graft occlusion. Graft occlusion was more frequent in vessels with high vFFR values. Grafted native coronary vessels exhibited accelerated functional CAD progression, whereas in non-grafted native coronaries the functional status remained unchanged.

Percutaneous Transfemoral TAVR With Direct Puncture and Successful Closure of Aortobifemoral Bypass Graft.

Two successful cases of percutaneous transfemoral transcatheter aortic valve replacement (TAVR) in patients with previous aortobifemoral bypass graft surgery are presented. Both cases demonstrate feasibility of this strategy after careful preprocedural planning and suggest transfemoral TAVR can also be considered for patients when alternative access and/or general anaesthesia is excluded.

Les auteurs présentent deux cas de remplacement valvulaire aortique par cathéter (RVAC) réalisé par voie transfémorale percutanée chez des patients ayant déjà subi un pontage aorto-bifémoral. Ces deux cas montrent la faisabilité d'une telle intervention après une planification minutieuse et portent à croire qu'un RVAC transfémoral pourrait aussi être envisagé lorsqu'il n'y a pas d'autre accès possible et/ou qu'une anesthésie générale est contre-indiquée.

Rationale and design of the Flow Evaluation to Guide Revascularization in Multivessel ST-Elevation Myocardial Infarction (FLOWER-MI) trial.

BACKGROUND: In ST-elevation myocardial infarction (STEMI) patients presenting with multivessel disease (MVD), recent studies have demonstrated the superiority of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for non-culprit lesions compared to culprit lesion treatment-only therapy. FFR- and angio-guided PCI have however never been compared in STEMI patients. TRIAL DESIGN: FLOWER-MI is an open-label multicenter national randomized clinical trial. The aim is to investigate FFR-guided complete revascularization in comparison to angio-guided complete revascularization in STEMI patients with successful PCI of the culprit lesion and ≥50% stenosis in at least one additional non-culprit lesion requiring PCI. Eligible patients will be randomized after successful primary PCI in a 1:1 fashion to either FFR-guided or angio-guided complete revascularization during the index procedure or a staged procedure before discharge (≤5 days). Patients assigned to FFR guidance first have FFR measured in each non-culprit vessel and only undergo PCI if FFR is ≤0.80. The primary end point of the study is a composite of major adverse cardiac events, including all-cause death, non-fatal MI, and unplanned hospitalization leading to urgent revascularization at 1 year. Secondary end points will include the individual adverse events, cost-effectiveness, quality of life, and 30-day, 6-month, and 3-year outcomes. Based on estimated event rates, a sample size of 1170 patients is needed to show superiority of the FFR-guided revascularization with 80% power. CONCLUSION: The aim of FLOWER-MI trial is to assess whether FFR-guided complete revascularization in the acute setting is superior angio-guided complete revascularization.