A randomized clinical study using optical coherence tomography to evaluate the short-term effects of high-intensity interval training on cardiac allograft vasculopathy: a HITTS substudy.

Cardiac allograft vasculopathy (CAV) remains a leading cause of long-term mortality after heart transplantation. Both preventive measures and treatment options are limited. This study aimed to evaluate the short-term effects of high-intensity interval training (HIT) on CAV in de novo heart transplant (HTx) recipients as assessed by optical coherence tomography (OCT). The study population was a subgroup of the 81-patient HITTS study in which HTx recipients were randomized to HIT or moderate intensity continuous training (MICT) for nine consecutive months. OCT images from baseline and 12 months were compared to assess CAV progression. The primary endpoint was defined as the change in the mean intima area. Paired OCT data were available for 56 patients (n = 23 in the HIT group and n = 33 in the MICT group). The intima area in the entire study population increased by 25% [from 1.8±1.4 mm2 to 2.3±2.0 mm2 , P < .05]. The change was twofold higher in the MICT group (.6±1.2 mm2 ) than in the HIT group (.3±.6 mm2 ). However, the treatment effect of HIT was not significant (treatment effect = -.3 mm2 , 95% CI [-.825 to .2 mm2 ] P = .29). These results suggest that early initiation of HIT compared with MICT does not attenuate CAV progression in de novo HTx recipients.

Immediate post-procedural functional assessment of percutaneous coronary intervention: current evidence and future directions.

Percutaneous coronary intervention (PCI) guided by coronary physiology provides symptomatic benefit and improves patient outcomes. Nevertheless, over one-fourth of patients still experience recurrent angina or major adverse cardiac events following the index procedure. Coronary angiography, the current workhorse for evaluating PCI efficacy, has limited ability to identify suboptimal PCI results. Accumulating evidence supports the usefulness of immediate post-procedural functional assessment. This review discusses the incidence and possible mechanisms behind a suboptimal physiology immediately after PCI. Furthermore, we summarize the current evidence base supporting the usefulness of immediate post-PCI functional assessment for evaluating PCI effectiveness, guiding PCI optimization, and predicting clinical outcomes. Multiple observational studies and post hoc analyses of datasets from randomized trials demonstrated that higher post-PCI functional results are associated with better clinical outcomes as well as a reduced rate of residual angina and repeat revascularization. As such, post-PCI functional assessment is anticipated to impact patient management, secondary prevention, and resource utilization. Pre-PCI physiological guidance has been shown to improve clinical outcomes and reduce health care costs. Whether similar benefits can be achieved using post-PCI physiological assessment requires evaluation in randomized clinical outcome trials.

Resting distal to aortic pressure ratio and fractional flow reserve discordance affects the diagnostic performance of quantitative flow ratio: Results from an individual patient data meta-analysis.

OBJECTIVE: To evaluate the diagnostic performance of quantitative flow ratio (QFR) related to fractional flow reserve (FFR) and resting distal-to-aortic pressure ratio (resting Pd/Pa) concordance. BACKGROUND: QFR is a method for computation of FFR based on standard coronary angiography. It is unclear how QFR is performed in patients with discordance between FFR and resting pressure ratios (distal-to-aortic pressure ratio [Pd/Pa]). MATERIALS AND METHODS: The main comparison was the diagnostic performance of QFR with FFR as reference stratified by correspondence between FFR and resting Pd/Pa. Secondary outcome measures included distribution of clinical or procedural characteristics stratified by FFR and resting Pd/Pa correspondence. RESULTS: Four prospective studies matched the inclusion criteria. Analysis was performed on patient level data reaching a total of 759 patients and 887 vessels with paired FFR, QFR, and resting Pd/Pa. Median FFR was 0.85 (IQR: 0.77-0.90). Diagnostic accuracy of QFR with FFR as reference was higher if FFR corresponded to resting Pd/Pa: accuracy 90% (95% CI: 88-92) versus 72% (95% CI: 64-80), p < .001, and sAUC 0.95 (95% CI: 0.92-0.96) versus 0.73 (95% CI: 0.69-0.77), p < .001. Resting Pd/Pa and FFR discordance were related to age, sex, hypertension, and lesion severity. CONCLUSION: Diagnostic performance of QFR with FFR as reference is reduced for lesions with discordant FFR (≤0.80) and resting Pd/Pa (≤0.92) measurements.

Micro- and macrovascular cardiac allograft vasculopathy in relation to 91 cardiovascular biomarkers in heart transplant recipients-An exploratory study.

BACKGROUND: Cardiac allograft vasculopathy (CAV) limits survival after heart transplantation (HTx), and the pathogenesis is not fully clarified. We aimed to investigate a wide range of biomarkers and their correlation with micro- and macrovascular CAV and major adverse cardiac events in HTx patients. METHODS: We evaluated 91 cardiovascular disease-related proteins in 48 HTx patients using a novel proteomic panel. Patients were dichotomized according to micro- and macrovascular CAV burden determined by coronary angiography, optical coherence tomography, and 15 O-H2 O positron emission tomography imaging. Major adverse cardiac events included significant CAV progression, heart failure, treated rejection, and cardiovascular death. RESULTS: We found consistent differences in two proteins involved in cholesterol homeostasis: significantly increased proprotein convertase subtilisin/kexin type 9 (PCSK9) (p < .05) and significantly decreased paraoxonase 3 (PON3) (p < .05). N-terminal pro-brain natriuretic peptide (NT-proBNP) was significantly increased in patients with microvascular CAV (p < .05) and borderline significantly increased in patients experiencing major adverse cardiac events (p = .10) and patients with macrovascular CAV (p = .05). CONCLUSIONS: We identified consistent changes in two proteins involved in cholesterol homeostasis which may be important players in the pathogenesis of CAV: PON3 and PCSK9. NT-proBNP also showed consistent changes across all groups but only reached statistical significance in patients with microvascular CAV. Our results warrant further validation in future studies.

Age-Stratified Outcome in Treatment of Left Main Coronary Artery Stenosis: A NOBLE Trial Substudy.

BACKGROUND: In the treatment of left main coronary artery (LMCA) disease, patients' age may affect the clinical outcome after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). This study stratified the clinical outcome according to the age of patients treated for LMCA stenosis with PCI or CABG in the Nordic-Baltic-British Left Main Revascularization (NOBLE) study. METHODS: Patients with LMCA disease were enrolled in 36 centers in northern Europe and randomized 1:1 to treatment by PCI or CABG. Eligible patients had stable angina pectoris, unstable angina pectoris, or non-ST elevation myocardial infarction. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCEs), a composite of all-cause mortality, nonprocedural myocardial infarction, any repeat coronary revascularization, and stroke. Age-stratified analysis was performed for the groups younger and older than 67 years and for patients older than 80 years. RESULTS: For patients ≥67 years, the 5-year MACCEs were 35.7 versus 22.3% (hazard ratio [HR] 1.72 [95% confidence interval [CI] 1.27-2.33], p = 0.0004) for PCI versus CABG. The difference in MACCEs was driven by more myocardial infarctions (10.8 vs. 3.8% HR 3.01 [95% CI 1.52-5.96], p = 0.0009) and more repeat revascularizations (19.5 vs. 10.0% HR 2.01 [95% CI 1.29-3.12], p = 0.002). In patients younger than 67 years, MACCE was 20.5 versus 15.3% (HR 1.38 [95% CI 0.93-2.06], p = 0.11 for PCI versus CABG. All-cause mortality was similar after PCI and CABG in both age-groups. On multivariate analysis, age was a predictor of MACCE, along with PCI, diabetes, and SYNTAX score. CONCLUSIONS: As the overall NOBLE results show revascularization of LMCA disease, age of 67 years or older was associated with lower 5-year MACCE after CABG compared to PCI. Clinical outcomes were not significantly different in the subgroup younger than 67 years, although no significant interaction was present between age and treatment. Mortality was similar for all subgroups (ClinicalTrials.gov identifier: NCT01496651).

Fractional flow reserve in clinical practice: from wire-based invasive measurement to image-based computation.

Fractional flow reserve (FFR) and instantaneous wave-free ratio are the present standard diagnostic methods for invasive assessment of the functional significance of epicardial coronary stenosis. Despite the overall trend towards more physiology-guided revascularization, there remains a gap between guideline recommendations and the clinical adoption of functional evaluation of stenosis severity. A number of image-based approaches have been proposed to compute FFR without the use of pressure wire and induced hyperaemia. In order to better understand these emerging technologies, we sought to highlight the principles, diagnostic performance, clinical applications, practical aspects, and current challenges of computational physiology in the catheterization laboratory. Computational FFR has the potential to expand and facilitate the use of physiology for diagnosis, procedural guidance, and evaluation of therapies, with anticipated impact on resource utilization and patient outcomes.

Danish study of Non-Invasive testing in Coronary Artery Disease 2 (Dan-NICAD 2): Study design for a controlled study of diagnostic accuracy.

BACKGROUND: Coronary computed tomography angiography (CTA) is the preferred primary diagnostic modality when examining patients with low to intermediate pre-test probability of coronary artery disease (CAD). Only 20-30% of these have potentially obstructive CAD. Because of the relatively poor positive predictive value of coronary CTA, unnecessary invasive coronary angiographies (ICAs) are conducted with the costs and risks associated with the procedure. Hence, an optimized diagnostic CAD algorithm may reduce the numbers of ICAs not followed by revascularization. The Dan-NICAD 2 study has 3 equivalent main aims: (1) To examine the diagnostic precision of a sound-based diagnostic algorithm, The CADScor®System (Acarix A/S, Denmark), in patients with a low to intermediate pre-test risk of CAD referred to a primary examination by coronary CTA. We hypothesize that the CADScor®System provides better stratification prior to coronary CTA than clinical risk stratification scores alone. (2) To compare the diagnostic accuracy of 3T cardiac magnetic resonance imaging (3T CMRI), 82rubidium positron emission tomography (82Rb-PET), and CT-derived fractional flow reserve (FFRCT) in patients where obstructive CAD cannot be ruled out by coronary CTA using ICA fractional flow reserve (FFR) as reference standard. (3) To compare the diagnostic performance of quantitative flow ratio (QFR) and ICA-FFR in patients with low to intermediate pre-test probability of CAD using 82Rb-PET as reference standard. METHODS: Dan-NICAD 2 is a prospective, multicenter, cross-sectional study including approximately 2,000 patients with low to intermediate pre-test probability of CAD and without previous history of CAD. Patients are referred to coronary CTA because of symptoms suggestive of CAD, as evaluated by a cardiologist. Patient interviews, sound recordings, and blood samples are obtained in connection with the coronary CTA. If coronary CTA does not rule out obstructive CAD, patients will be examined by 3T CMRI 82Rb-PET, FFRCT, ICA, and FFR. Reference standard is ICA-FFR. Obstructive CAD is defined as an FFR ≤0.80 or as high-grade stenosis (>90% diameter stenosis) by visual assessment. Diagnostic performance will be evaluated as sensitivity, specificity, predictive values, likelihood ratios, calibration, and discrimination. Enrolment started January 2018 and is expected to be completed by June 2020. Patients are followed for 10 years after inclusion. DISCUSSION: The results of the Dan-NICAD 2 study are expected to contribute to the improvement of diagnostic strategies for patients suspected of CAD in 3 different steps: risk stratification prior to coronary CTA, diagnostic strategy after coronary CTA, and invasive wireless QFR analysis as an alternative to ICA-FFR.

Diagnostic performance of quantitative flow ratio in prospectively enrolled patients: An individual patient-data meta-analysis.

OBJECTIVES: We aimed to provide robust performance estimates for quantitative flow ratio (QFR) in assessment of intermediary coronary lesions. BACKGROUND: Angiography-based functional lesion assessment by QFR may appear as a cost saving and safe approach to expand the use of physiology-guided percutaneous coronary interventions. QFR was proven feasible and showed good diagnostic performance in mid-sized off-line and on-line studies with fractional flow reserve (FFR) as reference standard. METHODS: We performed a collaborative individual patient-data meta-analysis of all available prospective studies with paired assessment of QFR and FFR using the CE-marked QFR application. The main outcome was agreement of QFR and FFR using a two-step analysis strategy with a multilevel mixed model accounting for study and center level variation. RESULTS: Of 16 studies identified, four studies had prospective enrollment and provided patient level data reaching a total of 819 patients and 969 vessels with paired FFR and QFR: FAVOR Pilot (n = 73); WIFI II (n = 170); FAVOR II China (n = 304) and FAVOR II Europe-Japan (n = 272). We found an overall agreement (mean difference 0.009 ± 0.068, I2 = 39.6) of QFR with FFR. The diagnostic performance was sensitivity 84% (95%CI: 77-90, I2 = 70.1), specificity 88% (95%CI: 84-91, I2 = 60.1); positive predictive value 80% (95%CI: 76-85, I2 = 33.4), and negative predictive value 95% (95%CI: 93-96, I2 = 75.9). CONCLUSIONS: Diagnostic performance of QFR was good with FFR as reference in this meta-analysis of high quality studies. QFR could provide an easy, safe, and cost-effective solution for functional evaluation of coronary artery stenosis.

Quantitative flow ratio for immediate assessment of nonculprit lesions in patients with ST-segment elevation myocardial infarction-An iSTEMI substudy.

OBJECTIVES: We evaluated the diagnostic performance of quantitative flow ratio (QFR) assessment of nonculprit lesions (NCLs) based on acute setting angiograms obtained in patients with ST-segment elevation myocardial infarction (STEMI) with QFR, fractional flow reserve (FFR), and instantaneous wave-free ratio (iFR) in the staged setting as reference. BACKGROUND: QFR is an angiography-based approach for the functional evaluation of coronary artery lesions. METHODS: This was a post-hoc analysis of the iSTEMI study. NCLs were assessed with iFR in the acute setting and with iFR and FFR at staged (median 13 days) follow-up. Acute and staged QFR values were computed in a core laboratory based on the coronary angiography recordings. Diagnostic cut-off values were ≤0.80 for QFR and FFR, and ≤0.89 for iFR. RESULTS: Staged iFR and FFR data were available for 146 NCLs in 112 patients in the iSTEMI study. Among these, QFR analysis was feasible in 103 (71%) lesions assessed in the acute setting with a mean QFR value of 0.82 (IQR: 0.73-0.91). Staged QFR, FFR, and iFR were 0.80 (IQR: 0.70-0.90), 0.81 (IQR: 0.71-0.88), and 0.91 (IQR: 0.87-0.96), respectively. Classification agreement of acute and staged QFR was 93% (95%Cl: 87-99). The classification agreement of acute QFR was 84% (95%CI: 76-90) using staged FFR as reference and 74% (95%CI: 65-83) using staged iFR as reference. CONCLUSIONS: Acute QFR showed a very good diagnostic performance with staged QFR as reference, a good diagnostic performance with staged FFR as reference, and a moderate diagnostic performance with staged iFR as reference.

Rational and design of the European randomized Optical Coherence Tomography Optimized Bifurcation Event Reduction Trial (OCTOBER).

Background: Percutaneous coronary intervention in complex bifurcation lesions is prone to suboptimal implantation results and is associated with increased risk of subsequent clinical events. Angiographic ambiguity is high during bifurcation stenting, but it is unknown if procedural guidance by intravascular optical coherence tomography (OCT) improves clinical outcome. Methods and Design: OCTOBER is a randomized, investigator-initiated, multicenter trial aimed to show superiority of OCT-guided stent implantation compared to standard angiographic-guided implantation in bifurcation lesions. The primary outcome measure is a 2-year composite end point of cardiac death, target lesion myocardial infarction, and ischemia-driven target lesion revascularization. The calculated sample size is 1,200 patients in total, and allocation is 1:1. Eligible patients have stable or unstable angina pectoris or stabilized non­ST elevation myocardial infarction, and a coronary bifurcation lesion with significant main vessel stenosis and more than 50 % stenosis in a side branch with a reference diameter ≥2.5mm. Treatment is performed by the provisional side branch stenting technique or 2-stent techniques, and the systematic OCT guiding protocol is aimed to evaluate (1) plaque preparation, (2) lesion length, (3) segmental reference sizes, (4) lesion coverage, (5) stent expansion, (6) malapposition, (7) wire positions, and (8) ostial results. Implications: A positive outcome of the OCTOBER trial may establish OCT as a routine tool for optimization of complex percutaneous coronary intervention, whereas a negative result would indicate that OCT remains a tool for ad hoc evaluation in selected cases.

Donor-specific antibodies are associated with micro- and macrovascular coronary disease, restrictive myocardial damage, and poor outcome in heart-transplanted patients.

AIMS: We examined the relationship between donor-specific HLA antibody (DSA) presence and graft function, hemodynamics, cardiac allograft vasculopathy (CAV), and major adverse cardiac events (MACE) in stable long-term heart-transplanted (HTx) patients. METHODS: Sera from 79 patients (median 7.5 years after HTx) were analyzed for DSA presence. Graft function was evaluated by echocardiography and right heart catheterization. CAV burden was determined by coronary angiography, optical coherence tomography (OCT), and coronary flow velocity reserve (CFVR). Patients were prospectively followed after DSA assessment. MACE included significant CAV progression, heart failure, treated rejection, and cardiovascular death. RESULTS: Sixty patients had no DSA, and 19 patients were sensitized. The vasculopathy burden by angiography, OCT, and CFVR was more pronounced in DSA-positive patients than in DSA-negative patients. DSA-positive patients had higher pulmonary capillary wedge pressure (16 [8; 21] vs 9 mm Hg [7; 11], P<.05) and right atrial pressure (8 [6; 9] vs 4 mm Hg [2; 6], P<.01) and lower global longitudinal strain (-13% [-10; -15] vs -16% [-14; -17], P<.01) than DSA-negative patients. DSA presence was a strong MACE predictor (HR 4.7 (95% CI 2.0-11.4), P<.001). CONCLUSIONS: DSA-positive patients had higher vasculopathy burden, higher filling pressures, and lower longitudinal myocardial deformation than DSA-negative patients. The DSA presence was a strong MACE predictor.

A 10-month angiographic and 4-year clinical outcome of everolimus-eluting versus sirolimus-eluting coronary stents in patients with diabetes mellitus (the DiabeDES IV randomized angiography trial).

OBJECTIVE: We aimed to compare angiographic and clinical outcomes after the implantation of everolimus-eluting (EES) and sirolimus-eluting (SES) stents in patients with diabetes. BACKGROUND: There are limited data on long-term outcome after EES vs SES implantation in diabetic patients. METHODS: We randomized 213 patients with diabetes and coronary artery disease to EES (n = 108) or SES (n = 105) implantation. Angiographic follow-up was performed 10 months after the index procedure and all patients were followed clinically for 4 years. The primary endpoint was angiographic in-stent late luminal loss at 10-month follow-up. Secondary endpoints included angiographic restenosis rate, the need for target lesion revascularization (TLR) and major adverse cardiac events (MACE; defined as cardiac death, myocardial infarction, definite stent thrombosis, or TLR) at 4-year follow-up. RESULTS: At 10-month angiographic follow-up, in-stent late lumen loss was 0.20 ± 0.53 mm and 0.11 ± 0.49 mm (P = 0.28), and angiographic restenosis rate was 3.8% and 5.2% (P = 0.72) in the EES and SES groups, respectively. At 4-year clinical follow-up, MACE had occurred in 22 (20.4%) patients in the EES group and 25 (23.8%) patients in SES group (HR 0.84, 95% CI 0.47-1.49; P = 0.55), with TLR performed in 6 (5.6%) and 10 (9.5%) patients in the two groups (HR 0.57, 95% CI 0.21-1-58; P = 0.28). CONCLUSION: EES and SES had comparable 10-month angiographic and 4-year clinical outcomes in patients with diabetes mellitus and coronary artery disease.

Clinical use of optical coherence tomography to identify angiographic silent stent thrombosis.

OBJECTIVES: Patients previously treated with coronary stents may suffer an acute coronary syndrome (ACS) without any evidence of thrombus formation on coronary angiography (CAG). This may be due to partial, nonocclusive stent thrombosis with microembolization. In this paper, we illustrate possible mechanisms both with optical coherence tomography (OCT) and histology. DESIGN: We present two cases with ACS from very late stent thrombosis who have been previously treated with first-generation drug-eluting stents (DES). RESULTS: The first patient had ACS 15 months after DES implantation. The angiogram (CAG) was near normal with slight peri-stent contrast staining. OCT revealed abnormalities including thrombus not visible on CAG. These are findings that may explain the ACS. The second patient had subclinical episodes with chest pain after DES implantation. The patient died from stent thrombosis in a DES. Postmortem histological examination of the coronary arteries revealed stent struts with little or no neointimal coverage, persistent peri-strut fibrin deposition, inflammatory cells, malapposition, and small luminal platelet-rich thrombi. Old spotty myocardial infarctions were found in the supplied territory possibly caused by earlier episodes of embolizing thrombus. CONCLUSIONS: In patients with previous implanted DES presenting with ACS, OCT may detect abnormalities and thrombus formation not visible on CAG. Such findings may impact the treatment strategy in these patients.

Randomized study to assess the effect of thrombus aspiration on flow area in patients with ST-elevation myocardial infarction: an optical frequency domain imaging study--TROFI trial.

AIMS: Primary percutaneous coronary intervention (PPCI) with thrombectomy (TB) seems to reduce the thrombus burden, resulting in a larger flow area as measured with optical frequency domain imaging (OFDI). METHODS AND RESULTS: In a multi-centre study, 141 patients with ST elevation myocardial infarction <12 h from onset were randomized to either PPCI with TB using an Eliminate catheter (TB: n = 71) or without TB (non-TB: n = 70), having operators blinded for the OFDI results. The primary endpoint was minimum flow area (MinFA) post-procedure assessed by OFDI, defined as: [stent area + incomplete stent apposition (ISA) area] - (intraluminal defect + tissue prolapse area). Sample size was based on the expected difference of 0.72 mm(2) in MinFA. Baseline demographics, pre-procedural quantitative coronary angiography (QCA), and procedural characteristics were well matched between the two groups. On OFDI, the stent area (TB: 7.62 ± 2.23 mm(2), non-TB: 7.05 ± 2.12 mm(2), P = 0.14) and MinFA (TB: 7.08 ± 2.14 mm(2) vs. non-TB: 6.51 ± 1.99 mm(2), Δ0.57 mm(2), P = 0.12) were not different. In addition, the amount of protrusion, intraluminal defect, and ISA area were similar in the both groups. CONCLUSION: PPCI with TB was associated with a similar flow area as well as stent area to PPCI without TB.

Clinical Likelihood Prediction of Hemodynamically Obstructive Coronary Artery Disease in Patients With Stable Chest Pain.

BACKGROUND: Selection for invasive angiography is recommended to be based on pretest probabilities (PTPs), and physiological measures of hemodynamical impairment by, for example, fractional flow reserve (FFR) should guide revascularization. The risk factor-weighted clinical likelihood (RF-CL) and coronary artery calcium score-weighted clinical likelihood (CACS-CL) models show superior discrimination of patients with suspected obstructive coronary artery disease (CAD), but validation against hemodynamic impairment is warranted. OBJECTIVES: The aim of this study was to validate the RF-CL and CACS-CL models against hemodynamically obstructive CAD. METHODS: Stable de novo chest pain patients (N = 4,371) underwent coronary computed tomography angiography and subsequently invasive coronary angiography with FFR measurements. Hemodynamically obstructive CAD was defined as invasive FFR ≤0.80 or high-grade stenosis by visual assessment (>90% diameter stenosis). For comparison, a guideline-endorsed basic PTP model was calculated based on age, sex, and symptom typicality. The RF-CL model additionally included the number of risk factors, and the CACS-CL model incorporated the coronary artery calcium score into the RF-CL. RESULTS: In total, 447 of 4,371 (10.9%) patients had hemodynamically obstructive CAD. Both the RF-CL and CACS-CL models classified more patients with a very low clinical likelihood (≤5%) of obstructive CAD compared to the basic PTP model (33.0% and 53.7% vs 12.0%; P < 0.001) with a preserved low prevalence of hemodynamically obstructive CAD (<5% for all models). Against hemodynamically obstructive CAD, calibration and discrimination of the RF-CL and CACS-CL models were superior to the basic PTP model. CONCLUSIONS: The RF-CL and CACS-CL models are well calibrated and superior to a currently recommended basic PTP model to predict hemodynamically obstructive CAD. (Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease [Dan-NICAD]; NCT02264717; Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 2 [Dan-NICAD 2]; NCT03481712, Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 3 [Dan-NICAD 3]; NCT04707859).

Comparison of definitions of coronary artery reference sizes and effects on stent selection and evaluation of stent expansion.

Accurate determination of coronary reference size is essential for optimal stent selection and evaluation of stent expansion during percutaneous coronary intervention (PCI). Several approaches for reference size estimation have been published with no universal agreement. The aim of this study was to investigate if potential differences in coronary reference size estimation lead to differences in stent and balloon selection and in detection of stent under expansion. Definitions for coronary reference size estimation, stent size selection, and stent expansion were identified in 17 randomized controlled trials. The identified methods were applied in a population of 32 clinical cases. Reference size estimates ranged up to 1.35mm, and indicated nominal stent size ranged up to 1.0 mm in the same case depending on method. Mean relative stent expansion ranged from 54±12% to mean 100±29% depending on the applied reference method. Choice of method for reference size estimation using intravascular imaging may influence stent selection and greatly affects evaluation of post-PCI stent expansion.

Predictive value of post-percutaneous coronary intervention fractional flow reserve: a systematic review and meta-analysis.

AIMS: We aimed to investigate the relationship between post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and clinical outcome using a systematic review with a study-level meta-analysis. METHODS AND RESULTS: MEDLINE, Embase, and CENTRAL were systematically searched for articles with clinical follow-up reporting mean or median final post-PCI FFR. The main outcome was a composite of major adverse cardiac events (MACE) including all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR). Meta-regression analyses were performed on mean post-PCI FFR values. A total of 62 studies with 12 340 patients and 12 923 stented vessels were included, with follow-ups ranging from 1 to 89 months. Post-PCI FFR was not continuously associated with the rate of 1-year MACE or 1-year TVR using meta-regression models accounting for heterogeneous follow-up lengths. For studies comparing high vs. low post-PCI FFR, low post-PCI FFR was associated with high risk ratio for MACE {1.97 [95% confidence interval (CI):1.45-2.67]}, all-cause death [1.59 (95% CI: 1.08-2.34)], MI [3.18 (95% CI: 1.84-5.50)], TVR [2.08 (95% CI: 1.63-2.65)] and angina status [2.50 (95% CI: 1.53-4.06)] using different optimal cut-off values spanning from 0.80 to 0.95. CONCLUSION: We found no clear continuous association between post-PCI FFR and clinical outcomes in this systematic study-level meta-analysis. In a subset of studies investigating binary classification, high post-PCI FFR was associated with a better clinical outcome than low post-PCI FFR.We investigated the relationship between post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and rate of major adverse cardiac events (MACE), including all-cause death, myocardial infarction (MI), and target vessel revascularization (TVR), using a systematic review and study-level meta-analysis, pooling 12 340 patients from 62 studies. Mean post-PCI FFR was not continuously associated with a 1-year MACE rate accounting for heterogenous follow-up lengths. Still, the risk ratio favoured high post-PCI FFR for reduced MACE, all-cause death, MI, TVR, and better angina status using different cut-offs.

Anatomical classification of chronic total occlusions in coronary bifurcations.

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) in coronary bifurcation lesions (CBL) is undergoing substantial technical progress and standardization, paralleling the evolution of dedicated devices, tools, and techniques. A standard consensus to classify CTO-CBL might be instrumental to homogenize data collection and description of procedures for scientific and educational purposes. The Medina-CTO classification replicates the classical three digits in Medina classification for bifurcations, representing the proximal main vessel, distal main vessel, and side branch, respectively. Each digit can take a value of 1 if it concerns atherosclerosis and is anatomically stenosed, or 0 if it is not. In addition, the occluded segment(s) of the bifurcation are noted by a subscript, which describes key interventional features of the cap: t (tapered), b (blunt), or a (ambiguous). This approach results in 56 basic categories that can be grouped by means of different elements, depending on the specific needs of each study. Medina-CTO classification, consisting of adding a subscript describing the basic cap characteristics to the totally occluded segment(s) of the standard Medina triplet, might be a useful methodological tool to standardize percutaneous intervention of bifurcational CTO lesions, with interesting scientific and educational applications.

Everolimus-eluting bioresorbable scaffold versus everolimus-eluting metallic stent in primary percutaneous coronary intervention of ST-segment elevation myocardial infarction: a randomized controlled trial.

BACKGROUND: Primary percutaneous coronary intervention with implantation of a metallic drug-eluting stent (DES) is the standard treatment for patients presenting with ST-elevation myocardial infarction (STEMI). Implantation of a bioresorbable scaffold (BRS) during STEMI represents a novel strategy without intravascular metal. OBJECTIVE: The aim of the study was to investigate 12-month healing response in an STEMI population after implantation of either the Absorb BRS or Xience DES (Abbott Vascular, USA). METHODS: The present trial was a prospective, randomized, controlled, nonblinded, noninferiority study with planned inclusion of 120 patients with STEMI. Patients were randomly assigned 1:1 to treatment with Absorb BRS or Xience DES. Implantation result and healing response were evaluated by angiography and optical coherence tomography (OCT) at baseline and 12-month follow-up. The primary endpoint was minimum flow area (MFA) assessed at 12 months. Coronary stent healing index (CSHI) was calculated from OCT images. RESULTS: Out of 66 included patients, 58 had follow-up OCT after 12 months, and 49 entered matched analysis. One death occurred in each group; none were stent-related. MFA was 5.13 ± 1.70 mm2 (95% CI, 4.44-5.82) in the BRS group compared with 6.30 ± 2.49 mm2 (95% CI, 5.22-7.37) (P = 0.06) in the DES group. Noninferiority could not be evaluated. CSHI for both groups had a median score of 3. CONCLUSION: The DES group performed numerically better in primary and secondary endpoints, but the CSHI showed good stent healing in both groups.