Implicancias de la inteligencia artificial en los métodos de imagen endovascular / Implications of Artificial Intelligence in Intravascular Imaging Methods

RESUMEN La angioplastia transluminal coronaria (ATC) es una de las principales estrategias de revascularización en pacientes con enfermedad coronaria aterosclerótica (ECA). Numerosos estudios respaldan la optimización de la ATC mediante métodos de imagen endovascular; sin embargo, estos métodos son subutilizados en la práctica clínica contemporánea y enfrentan desafíos en la interpretación de los datos obtenidos, por lo que la integración de la inteligencia artificial (IA) se vislumbra como una solución atractiva para promover y simplificar su uso. La IA se define como un programa computarizado que imita la capacidad del cerebro humano para recopilar y procesar datos. El aprendizaje de máquinas es una subdisciplina de la IA que implica la creación de algoritmos capaces de analizar grandes conjuntos de datos sin suposiciones previas, mientras que el aprendizaje profundo se centra en la construcción y entrenamiento de redes neuronales artificiales profundas y complejas. Así, se ha demostrado que la incorporación de sistemas de IA a los métodos de imagen endovascular incrementa la precisión de la ATC, disminuye el tiempo del procedimiento y la variabilidad interobservador en la interpretación de los datos obtenidos, promueve así una mayor adopción y facilita su utilización. El propósito de la presente revisión es destacar cómo los sistemas actuales basados en IA pueden desempeñar un papel fundamental en la interpretación de los datos generados por los métodos de imagen endovascular, lo que conduce a una mejora en la optimización de la ATC en pacientes con ECA.

ABSTRACT Percutaneous coronary intervention (PCI) is one of the primary revascularization strategies in patients with coronary artery disease (CAD). Several studies support the use of intravascular imaging methods to optimize PCI. However, these methods are underutilized in contemporary clinical practice and face challenges in data interpretation. Therefore, the incorporation of artificial intelligence (AI) is seen as an attractive solution to promote and simplify their use. AI can be defined as a computer program that mimics the human brain in its ability to collect and process data. Machine learning is a sub-discipline of AI that involves the creation of algorithms capable of analyzing large datasets without making prior assumptions, while deep learning focuses on the construction and training of deep and complex artificial neural networks. The incorporation of AI systems to intravascular imaging methods improves the accuracy of PCI, reduces procedure duration, and minimizes interobserver variability in data interpretation. This promotes their wider adoption and facilitates their use. The aim of this review is to highlight how current AI-based systems can play a key role in the interpretation of data generated by intravascular imaging methods and optimize PCI in patients with CAD.

Treatment with SGLT2 Inhibitors in Patients with Diabetes Mellitus and Extensive Coronary Artery Disease: Mortality and Cardiovascular Outcomes.

INTRODUCTION: Sodium-glucose type 2 cotransporter inhibitors (SGLT2-I) have shown solid benefits in reducing cardiovascular mortality and admissions for heart failure in patients with type 2 diabetes mellitus (T2DM) and cardiovascular disease. However, no specific studies exist in patients with high-risk coronary artery disease (CAD). METHODS: Single-center, retrospective, observational study including patients with T2DM and a new diagnosis of extensive CAD (defined as left main disease or three main coronary vessel disease). Patients were recruited from 2015 until 2020, with a follow-up of at least 12 months. The primary outcome was to compare all-cause mortality in patients treated with or without SGLT2-I at discharge and adjusted by inverse probability of treatment weighting (IPTW) propensity score. RESULTS: A total of 420 patients were included: 104 (24.7%) were treated with SGLT2-I and 316 (75.3%) were not (non-SGLT2-I group). The presentation was acute coronary syndrome in 44.3%. The mean age was 71.2 ± 10.5 years. The mean left ventricular ejection fraction was 51.5 ± 12.5%, and the mean estimated glomerular filtration rate was 73.9 ± 22 ml/min. After a mean follow-up of 3 ± 1.6 years, all-cause mortality was 16.4%, and cardiovascular mortality was 9.5%. After IPTW, the risk of all-cause death was lower in the SGLT2-I group with a hazard ratio of 0.32 (95% confidence interval 0.12-0.81), p = 0.016. With regard to secondary outcomes, patients in the SGLT2-I group were associated with less renal function deterioration but an increase in unplanned revascularizations. CONCLUSIONS: In patients with T2DM and extensive CAD, treatment with SGLT2-I after discharge was associated with a reduced risk of all-cause death.

Procedural and Technological Innovations Facilitating Ultra-low Contrast Percutaneous Coronary Interventions.

Ultra-low-dose contrast percutaneous coronary intervention (PCI) is a valuable approach in selected complex high-risk patients with renal failure. One of the objectives of ultra-low contrast PCI is to decrease the probability of developing postprocedural contrast-induced nephropathy (CIN), which predominately affects patients with baseline renal dysfunction. CIN is associated with poor clinical outcomes and increased healthcare-related costs. Another two clinical scenarios in which reduced dependence on contrast administration by the operator may contribute to improved safety are PCI in complex, high-risk indicated patients and in shock. In this review, we discuss the procedural techniques and recent technological innovations that enable ultra-low-dose contrast PCI to be performed in the cardiac cath lab.

Association between hormone therapy and short-term cardiovascular events in women with spontaneous coronary artery dissection.

INTRODUCTION AND OBJECTIVES: Changes in sex hormone levels are a known triggering factor for spontaneous coronary artery dissection (SCAD) in women. However, it is unknown whether exposure to exogenous hormone therapy (HT) at the time of SCAD presentation modifies the clinical course of this condition. We investigated the association between HT in female patients presenting with SCAD and short-term clinical outcomes. METHODS: We enrolled consecutive patients presenting with SCAD from the DISCO-IT/SPA (dissezioni spontanee coronariche Italian-Spanish) registry. Women on HT (estrogens, progestagens, or gonadotropins) at the time of presentation were identified, and their clinical characteristics and short-term outcomes were compared with those not receiving active HT. The outcome measure was nonfatal myocardial infarction and/or unplanned percutaneous coronary intervention during the first 28 days after the index catheterization. RESULTS: Of 224 women presenting with SCAD (mean age 52.0±10.0 years), 39 (17.4%) were currently using HT while 185 (82.6%) were not. No significant differences were noted in the baseline demographics, clinical presentation, angiographic features, or initial treatment received between the 2 groups. All patients on systemic HT (n=36, 92%) discontinued it at the time of diagnosis. The composite outcome occurred in 7 (17.9%) patients with prior HT compared with 14 (7.6%) without (P=.039). After multivariable adjustment, HT remained associated with the composite outcome recorded in the first 28 days of follow-up (HR, 3.53; 95%CI, 1.30-9.61; P=.013). CONCLUSIONS: In women with SCAD, exposure to HT at the time of clinical presentation was associated with short-term recurrent cardiovascular events such as nonfatal myocardial infarction and/or unplanned percutaneous revascularization.

Coronary Physiology as Part of a State-of-the-Art Percutaneous Coronary Intervention Strategy: Lessons from SYNTAX II and Beyond.

The use of coronary physiology allows for rational decision making at the time of PCI, contributing to better patient outcomes. Yet, coronary physiology is only one aspect of optimal revascularization. State-of-the-art PCI must also consider other important aspects such as intracoronary imaging guidance and specific procedural expertise, as tested in the SYNTAX II study. In this review, we highlight the technical aspects pertaining to the use of physiology as used in that trial and offer a glimpse into the future with emerging physiologic metrics, including functional coronary angiography, which have already established themselves as useful indices to guide decision making.

Age-related changes in the coronary microcirculation influencing the diagnostic performance of invasive pressure-based indices and long-term patient prognosis.

OBJECTIVES: Investigate age-related changes in coronary microvascular function, its effect on hyperemic and non-hyperemic indices of stenosis relevance, and its prognostic implications. BACKGROUND: Evidence assessing the effect of age on fractional flow reserve (FFR), resting mean distal intracoronary pressure/mean aortic pressure (Pd/Pa), and microcirculatory function remains scarce. METHODS: This is a post hoc study of a large prospective international registry (NCT03690713) including 1134 patients (1326 vessels) with coronary stenoses interrogated with pressure and flow guidewires. Age-dependent correlations with functional indices were analyzed. Prevalences of FFR, resting Pd/Pa, and coronary flow reserve (CFR) classification agreement were assessed. At 5 years follow-up, the relation between resting Pd/Pa, CFR, and their age-dependent implications on FFR-guided percutaneous coronary intervention (PCI) deferral (deferred if FFR > 0.80) were investigated using vessel-oriented composite outcomes (VOCO) composed of death, myocardial infarction, and repeated revascularization. RESULTS: Age correlated positively with FFR (r = 0.08, 95% confidence interval [CI]: 0.03 to 0.13, p = 0.005), but not with resting Pd/Pa (r = -0.03, 95% CI:-0.09 to 0.02, p = 0.242). CFR correlated negatively with age (r = -0.15, 95% CI: -0.21 to -0.10, p < 0.001) due to a significant decrease in maximal hyperemic flow in older patients. Patients over 60 years of age with FFR-guided deferred-PCI abnormal resting Pd/Pa or abnormal CFR had increased risk of VOCO (hazard ratio [HR]: 2.10, 95% CI: 1.15 to 4.36, p = 0.048; HR: 2.46, 95% CI:1.23 to 4.96, p = 0.011; respectively). CONLUSIONS: Aging is associated with decrease in microcirculatory vasodilation, as assessed with adenosine-based methods like CFR. In patients older than 60 years in whom PCI is deferred according to FFR > 0.80, CFR and resting Pd/Pa have an incremental value in predicting future vessel-oriented patient outcomes.

Sex Differences in 10-Year Outcomes Following STEMI: A Subanalysis From the EXAMINATION-EXTEND Trial.

BACKGROUND: Short-term outcomes following ST-segment elevation myocardial infarction (STEMI) in women are worse than in men, with a higher mortality rate. It is unknown whether sex plays a role in very long term outcomes. OBJECTIVES: The aim of this study was to assess whether very long term outcomes following STEMI treatment are influenced by sex. METHODS: EXAMINATION-EXTEND (10-Year Follow-Up of the EXAMINATION Trial) was an investigator-driven 10-year follow-up of the EXAMINATION (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) trial, which randomly 1:1 assigned 1,498 patients with STEMI to receive either everolimus-eluting stents or bare-metal stents. The present study was a subanalysis according to sex. The primary endpoint was the composite patient-oriented endpoint (all-cause death, any myocardial infarction, or any revascularization) at 10 years. Secondary endpoints were individual components of the primary endpoint. All endpoints were adjusted for age. RESULTS: Among 1,498 patients with STEMI, 254 (17%) were women. Overall, women were older, with more arterial hypertension and less smoking history than men. At 10 years, no difference was observed between women and men for the patient-oriented composite endpoint (40.6% vs 34.2%; adjusted HR: 1.14; 95% CI: 0.91-1.42; P = 0.259). There was a trend toward higher all-cause death in women vs men (27.6% vs 19.4%; adjusted HR: 1.30; 95% CI: 0.99-1.71; P = 0.063), with no difference in cardiac death or other endpoints. CONCLUSIONS: At very long term follow-up, there were no differences in the combined patient-oriented endpoint between women and men, with a trend toward higher all-cause death in women not driven by cardiac death. The present findings underline the need for focused personalized medicine in women after percutaneous revascularization aimed at both cardiovascular and sex-specific risk factor control and targeted treatment. (10-Years Follow-Up of the EXAMINATION Trial [EXAMINAT10N]; NCT04462315).

Five-year outcomes after state-of-the-art percutaneous coronary revascularization in patients with de novo three-vessel disease: final results of the SYNTAX II study.

AIMS: The SYNTAX II study evaluated the impact of advances in percutaneous coronary intervention (PCI), integrated into a single revascularization strategy, on outcomes of patients with de novo three-vessel disease. The study employed decision-making utilizing the SYNTAX score II, use of coronary physiology, thin-strut biodegradable polymer drug-eluting stents, intravascular ultrasound, enhanced treatments of chronic total occlusions, and optimized medical therapy. Patients treated with this approach were compared with predefined patients from the SYNTAX I trial. METHODS AND RESULTS: SYNTAX II was a multicentre, single-arm, open-label study of patients requiring revascularization who demonstrated clinical equipoise for treatment with either coronary artery bypass grafting (CABG) or PCI, predicted by the SYNTAX score II. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE), which included any revascularization. The comparators were a matched PCI cohort trial and a matched CABG cohort, both from the SYNTAX I trial. At 5 years, MACCE rate in SYNTAX II was significantly lower than in the SYNTAX I PCI cohort (21.5% vs. 36.4%, P < 0.001). This reflected lower rates of revascularization (13.8% vs. 23.8%, P < 0.001), and myocardial infarction (MI) (2.7% vs. 10.4%, P < 0.001), consisting of both procedural MI (0.2% vs. 3.8%, P < 0.001) and spontaneous MI (2.3% vs. 6.9%, P = 0.004). All-cause mortality was lower in SYNTAX II (8.1% vs. 13.8%, P = 0.013) reflecting a lower rate of cardiac death (2.8% vs. 8.4%, P < 0.001). Major adverse cardiac and cerebrovascular events' outcomes at 5 years among patients in SYNTAX II and predefined patients in the SYNTAX I CABG cohort were similar (21.5% vs. 24.6%, P = 0.35). CONCLUSIONS: Use of the SYNTAX II PCI strategy in patients with de novo three-vessel disease led to improved and durable clinical results when compared to predefined patients treated with PCI in the original SYNTAX I trial. A predefined exploratory analysis found no significant difference in MACCE between SYNTAX II PCI and matched SYNTAX I CABG patients at 5-year follow-up.

Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review.

The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration.

Dose-reducing fluoroscopic system decreases patient but not occupational radiation exposure in chronic total occlusion intervention.

AIMS: Several novel low-dose fluoroscopic systems (LDS) developed recently, but real practice information of the net benefit for the patient and professionals is scarce. We evaluated separately patient and operator radiation exposure during percutaneous interventions of chronic total occlusions (CTO). METHODS: A total of 116 consecutive CTOs were analyzed (60 in LDS and 56 in standard-dose fluoroscopic system [SDS]). Digital dosimetry of patient and occupational (operator and scatter dose) exposure was prospectively recorded. RESULTS: Biometrics, demographics, CTO variables, and operators were distributed evenly. Patient radiation exposure was effectively decreased in LDS (dose area product [DAP] by 36%, Air Kerma [AK] by 47%). However, occupational data showed no statistical differences between LDS and SDS. The LDS uses less radiation amount but with higher energy (due to additional filtration) compared to SDS, therefore increasing the scatter dose. When comparing the C-arm scatter dose to the DAP we found higher scatter dose with the LDS (0.0139 mSv/gray (Gy)*cm2 vs. 0.0082 mSv/Gy*cm2, p < .001). This was confirmed in a larger dataset comprising 5,221 coronary procedures. CONCLUSIONS: LDS was safer for patients reducing DAP and AK compared to SDS. However, occupational doses were not lower and scatter dose higher. Radiological protection measures must be kept maximized even in LDS.

Performance of the heart team approach in daily clinical practice in high-risk patients with aortic stenosis.

OBJECTIVE: The heart team (HT) approach plays a key role in selecting the optimal treatment strategy for patients with aortic stenosis (AS). However, little is known about the HT decision process and its impact on outcomes. The aim of this study was to identify the factors associated with the HT decision and evaluate clinical outcomes according to the treatment choice. METHODS: The study included a total of 286 consecutive patients with AS referred for discussion in the weekly HT meeting in a cardiovascular institute over 2 years. Patients were stratified according to the selected therapeutic approach: medical treatment (MT), surgical (SAVR), or transcatheter (TAVR) aortic valve replacement. Baseline characteristics involved in making a therapeutic choice were identified and a decision-making tree was built using classification and regression tree methodology. RESULTS: Based on HT discussion, 53 patients were assigned to SAVR, 210 to TAVR, and 23 to MT. Older patients (≥88 years old) were mainly assigned to TAVR or MT according to the logistic EuroSCORE (

High filtration in interventional practices reduces patient radiation doses but not always scatter radiation doses.

OBJECTIVES: In fluoroscopy-guided interventional practices, new dose reduction systems have proved to be efficient in the reduction of patient doses. However, it is not clear whether this reduction in patient dose is proportionally transferred to operators' doses. This work investigates the secondary radiation fields produced by two kinds of interventional cardiology units from the same manufacturer with and without dose reduction systems.Methods:Data collected from a large sample of clinical procedures over a 2-year period (more than 5000 procedures and 340,000 radiation events) and the DICOM radiation dose structured reports were analysed. RESULTS: The average cumulative Hp(10) per procedure measured at the C-arm was similar for the standard and the dose reduction systems (452 vs 476 µSv respectively). The events analysis showed that the ratio Hp(10)/KAP at the C-arm was (mean ± SD) 5 ± 2, 10 ± 4, 14 ± 4 and 14 ± 6 µSv·Gy-1·cm-2 for the beams with no added filtration, 0.1, 0.4 and 0.9 mm Cu respectively and suggested that the main cause for the increment of the ratio Hp(10)/KAP vs the "standard system" is the use of higher beam filtration in the "dose reduction" system. CONCLUSION: Dose reduction systems are beneficial to reduce KAP in patients and their use should be encouraged, but they may not be equally effective to reduce occupational doses. Interventionalists should not overlook their own personal protection when using new technologies with dose reduction systems. ADVANCES IN KNOWLEDGE: Dose reduction technology in interventional systems may increase scatter dose for operators. Personal protection should not be overlooked with dose reduction systems.

Role of Invasive and Non-invasive Imaging Tools in the Diagnosis and Optimal Treatment of Patients with Spontaneous Coronary Artery Dissection.

PURPOSE OF REVIEW: Spontaneous coronary artery dissection (SCAD) is a serious non-atherosclerotic disease, most frequently presenting as an acute coronary syndrome and affecting female patients. Considering that diagnosis of SCAD is often elusive, and its interventional treatment is associated to a higher rate of complications than obstructive atherosclerotic disease, we aim to review all the imaging tools currently available for the optimal diagnosis and treatment of this condition. RECENT FINDINGS: The developments in both invasive and non-invasive imaging alternatives to coronary angiography, such as intravascular ultrasound, optical coherence tomography, and computed coronary angiography, have largely contributed to appraise the epidemiology of SCAD, understand its causative pathophysiological mechanisms, and improve our ability to confirm doubtful cases of SCAD. Intracoronary imaging is also a valuable in deciding the best therapeutic approach and in guiding interventions in those patients requiring percutaneous treatment. Furthermore, non-invasive imaging is a key tool in ruling out significant extracoronary vascular abnormalities which frequently occur in patients with underlying conditions like fibromuscular dysplasia who develop SCAD. Main imaging tools employed in SCAD cases could have advantages and drawbacks. Focusing on different types of SCAD, operators should be able to choose the best imaging technique for diagnosis, management, and follow-up.

Screening of extra-coronary arteriopathy with magnetic resonance angiography in patients with spontaneous coronary artery dissection: a single-centre experience.

BACKGROUND: Current consensus recommends extended vascular investigation in patients with spontaneous coronary artery dissection (SCAD). We here report our experience with the use of magnetic resonance angiography (MRA) for screening extra-coronary arteriopathy in patients presenting with SCAD. METHODS: Patients presenting with SCAD in a Spanish centre underwent prospective contrast-enhanced MRA to assess the cephalic and abdominopelvic arterial territories. Fibromuscular dysplasia (FMD) was diagnosed following European consensus criteria. Other vascular abnormalities were recorded separately. Two vascular radiologists supervised the acquisitions and independently analysed the results for all cases. RESULTS: Forty patients with SCAD [mean age 50.9±8.6 years, 90% (n=36) women] were included in the study, 12 patients declined to participate and 5 were excluded (metallic implanted devices). All enrolled patients underwent the screening protocol without complications. MRA demonstrated at least one extra-coronary vascular abnormality in 16 patients (40%): 5 (12.5%) were diagnosed with FMD, 6 (15%) showed arterial tortuosity, 3 (7.5%) had non-FMD focal stenoses, and 2 (5%) were found to have small aneurysms at the celiac trunk and splenic artery. No intracranial aneurysms were detected. At a mean follow-up of 4±3 years from the index episode, two cases experienced SCAD recurrences, one in a patient with FMD and the other one in a patient with arterial tortuosity. No deaths or strokes occurred. CONCLUSIONS: Systematic extended vascular study with MRA was feasible and demonstrated associated extra-coronary arteriopathy in a substantial proportion of patients presenting with SCAD; however, none required additional intervention or led to vascular events. MRA, being a radiation-free modality, may be the preferred method for screening extracoronary arteriopathy in SCAD, a condition primarily affecting young and middle-age women sensitive to the risks of radiation.

Coronary Microcirculation Downstream Non-Infarct-Related Arteries in the Subacute Phase of Myocardial Infarction: Implications for Physiology-Guided Revascularization.

Background Concerns exist about reliability of pressure-wire-guided coronary revascularization of non-infarct-related arteries (non- IRA ). We investigated whether physiological assessment of non- IRA during the subacute phase of myocardial infarction might be flawed by microcirculatory dysfunction. Methods and Results We analyzed non- IRA that underwent fractional flow reserve, coronary flow reserve, and the index of microcirculatory resistance assessment. Microcirculation and hyperemic response were evaluated in 49 acute myocardial infarction patients (59 non- IRA ) and compared with a matched control group of 46 stable angina ( SA ) patients (59 vessels). Time between acute myocardial infarction to physiological interrogation was 5.9±2.4 days. Fractional flow reserve was similar in both groups (0.79±0.11 in non- IRA versus 0.80±0.13 in SA vessels, P=0.527). Lower coronary flow reserve values were found in non- IRA compared with SA vessels (1.77 [1.25-2.76] versus 2.44 [1.63-4.00], P=0.018), primarily driven by an increased baseline flow in non- IRA (rest mean transit time 0.58 [0.32-0.83] versus 0.65 s [0.39-1.20], P=0.045), whereas the hyperemic flow was similar (hyperemic mean transit time 0.26 [0.20-0.42] versus 0.26 s [0.18-0.35], P=0.873). No differences were found regarding index of microcirculatory resistance (15.6 [10.4-21.8] in non- IRA versus 16.7 [11.6-23.6] U in SA vessels, P=0.559). During adenosine infusion, the hyperemic response was similar in both groups (non- IRA versus SA vessels) in terms of the resistive reserve ratio (3.1±2.1 versus 3.7±2.2, P=0.118). Conclusions In the subacute phase of myocardial infarction, non- IRA show an increased baseline flow that may cause abnormal coronary flow reserve despite preserved hyperemic flow. In non- IRA , microcirculatory resistance and adenosine-induced hyperemic response are similar to those found in SA patients. From a physiological perspective, these findings support the use of fractional flow reserve to interrogate non- IRA during the subacute phase of myocardial infarction.

Procedural, Functional and Prognostic Outcomes Following Recanalization of Coronary Chronic Total Occlusions. Results of the Iberian Registry.

INTRODUCTION AND OBJECTIVES: There is current controversy regarding the benefits of percutaneous recanalization (PCI) of chronic total coronary occlusions (CTO). Our aim was to determine acute and follow-up outcomes in our setting. METHODS: Two-year prospective registry of consecutive patients undergoing PCI of CTO in 24 centers. RESULTS: A total of 1000 PCIs of CTO were performed in 952 patients. Most were symptomatic (81.5%), with chronic ischemic heart disease (59.2%). Previous recanalization attempts had been made in 15%. The mean SYNTAX score was 19.5 ± 10.6 and J-score was > 2 in 17.3%. A retrograde procedure was performed in 92 patients (9.2%). The success rate was 74.9% and was higher in patients without previous attempts (82.2% vs 75.2%; P = .001), those with a J-score ≤ 2 (80.5% vs 69.5%; P = .002), and in intravascular ultrasound-guided PCI (89.9% vs 76.2%, P = .001), which was an independent predictor of success. In contrast, severe calcification, length > 20mm, and blunt proximal cap were independent predictors of failed recanalization. The rate of procedural complications was 7.1%, including perforation (3%), myocardial infarction (1.3%), and death (0.5%). At 1-year of follow-up, 88.2% of successfully revascularized patients showed clinical improvement (vs 34.8%, P < .001), which was associated with lower mortality. At 1-year of follow-up, the mortality rate was 1.5%. CONCLUSIONS: Compared with other national registries, patients in the Iberian registry undergoing PCI of a CTO showed similar complexity, success rate, and complications. Successful recanalization was strongly associated with functional improvement, which was related to lower mortality.

Safety of intermediate left main stenosis revascularization deferral based on fractional flow reserve and intravascular ultrasound: A systematic review and meta-regression including 908 deferred left main stenosis from 12 studies.

BACKGROUND: Current guidelines recommend intravascular ultrasound (IVUS) or fractional flow reserve (FFR) to decide upon ambiguous left main (LM) disease. However, no study has compared the safety of LM revascularization deferral based on FFR or IVUS. METHODS: MEDLINE/PubMed was systematically screened for studies reporting on deferred treatment of angiographically ambiguous LM based upon FFR or IVUS evaluation. Baseline, angiographic and outcome data were appraised and pooled separately for each strategy according to random-effect models with inverse-variance weighting. RESULTS: A total of 908 LM stenoses from 7 FFR and 5 IVUS studies were included with median follow-up of 29.0 and 31.5 months respectively. Per year of follow-up occurrence of overall MACE were 5.1% in FFR group and 6.4% in IVUS group while death, myocardial infarction, LM revascularization were respectively 2.6%, 1.5% and 1.8% vs. 3.0%, 0.5% and 2.2%. Meta-regression analysis suggested the influence of a distal LM stenosis on MACE in FFR group (ß = 0.06, p = 0.01) and age in IVUS group (ß = 0.4, p = 0.001). In individual studies several independent predictors of MACE were identified including use of lower doses of intracoronary adenosine (OR 1.39, p = 0.04) in FFR group and plaque burden (OR 1.34, p = 0.025), number of other diseased vessels (OR 1.39, p = 0.04) and any untreated stenosis (OR 3.80; p = 0.037) in IVUS- studies. CONCLUSIONS: Deferring LM intermediate stenosis on the basis of FFR or IVUS showed an acceptable and similar risk of events in a mid-term follow-up. Conversely, several different variables related to each technique showed an interaction on outcome.

Internal mammary artery graft failure: Clinical features, management, and long-term outcomes.

OBJECTIVE: Data on long-term outcomes after internal mammary artery (IMA) coronary graft failure are scarce. Our objective was to describe the clinical characteristics, management, and prognosis after angiographically confirmed IMA graft failure following coronary revascularization. METHODS: A three-hospital retrospective registry, observational and descriptive, with prospective follow-up of all consecutive cases of IMA graft failure between 2004 and 2014 was conducted. After treatment, clinical and procedural features were compared between those with and without cardiovascular events. RESULTS: Fifty-seven patients were included (89% male, mean age: 62 years, at surgery) in the registry. Most patients underwent an IMA angioplasty (percutaneous coronary intervention [PCI], 74%). In nine cases, the PCI failed at the graft level, and seven underwent a native vessel revascularization. Native vessel treatment was performed in 20% of the study subjects, all with stents. Finally, medical management was decided in three cases. Events after treatment for IMA graft failure were frequent (50.8%), during a median follow-up of 7.5 years. Acute presentation (hazard ratioMACE = 1.35; 95% confidence interval (CI): 1.12-3.00, p < 0.01), age of the patient (hazard ratioMACE = 1.85, 95% CI: 1.17-2.11, p < 0.01), presence of diabetes mellitus (hazard ratioMACE = 2.75, 95% CI: 1.13-6.69, p = 0.02), and the management modality used (IMA-simple angioplasty VS IMA-stenting: hazard ratioMACE = 5.5, 95% CI: 1.40-21.15, p = 0.01) displayed prognostic relevance on multivariate analysis. All-cause mortality occurred in 21.1% and presentation as infarction (hazard ratioDEATH = 1.05, 95% CI: 1.01-2.17, p = 0.01), age (hazard ratioDEATH = 9.08, 95% CI: 2.52-32.69, p < 0.01), and left ventricular ejection fraction (hazard ratioDEATH = 3.68, 95% CI: 1.65-8.18, p < 0.01) were independent predictors of the same. CONCLUSIONS: In this long-term registry, most patients presented with an acute condition (myocardial infarction, progressive angina) within 12 months after surgery. Acute presentation, age, diabetes mellitus, reduced left ventricular ejection fraction, IMA graft failure segment affected, and the management strategy were related with long-term prognosis.

Identification of capillary rarefaction using intracoronary wave intensity analysis with resultant prognostic implications for cardiac allograft patients.

Aims: Techniques for identifying specific microcirculatory structural changes are desirable. As such, capillary rarefaction constitutes one of the earliest changes of cardiac allograft vasculopathy (CAV) in cardiac allograft recipients, but its identification with coronary flow reserve (CFR) or intracoronary resistance measurements is hampered because of non-selective interrogation of the capillary bed. We therefore investigated the potential of wave intensity analysis (WIA) to assess capillary rarefaction and thereby predict CAV. Methods and results: Fifty-two allograft patients with unobstructed coronary arteries and normal left ventricular (LV) function were assessed. Adequate aortic pressure and left anterior descending artery flow measurements at rest and with intracoronary adenosine were obtained in 46 of which 2 were lost to follow-up. In a subgroup of 15 patients, simultaneous RV biopsies were obtained and analysed for capillary density. Patients were followed up with 1-3 yearly screening angiography. A significant relationship with capillary density was noted with CFR (r = 0.52, P = 0.048) and the backward decompression wave (BDW) (r = -0.65, P < 0.01). Over a mean follow-up of 9.3 ± 5.2 years patients with a smaller BDW had an increased risk of developing angiographic CAV (hazard ratio 2.89, 95% CI 1.12-7.39; P = 0.03). Additionally, the index BDW was lower in those who went on to have a clinical CAV-events (P = 0.04) as well as more severe disease (P = 0.01). Conclusions: Within cardiac transplant patients, WIA is able to quantify the earliest histological changes of CAV and can predict clinical and angiographic outcomes. This proof-of-concept for WIA also lends weight to its use in the assessment of other disease processes in which capillary rarefaction is involved.

Spontaneous coronary artery dissection and aortic dilatation presenting concomitantly: a case report.

INTRODUCTION: Spontaneous coronary artery dissection (SCAD) is defined as a non-traumatic, non-iatrogenic, non-atherosclerotic separation of the coronary arterial walls, creating a false lumen. The space created is filled with an intramural haematoma (IMH) that compresses the true arterial lumen, decreasing anterograde blood flow. Spontaneous coronary artery dissection is commonly associated with small and medium sized extracoronary vascular abnormalities. CASE PRESENTATION: This case report describes a case of SCAD presenting as an acute coronary syndrome together with aortic dilatation requiring aortic valve and aortic root replacement. DISCUSSION: Despite the fact that SCAD and aortic dilatation share common aetiologies, this is the first case to our knowledge describing severe aortic dilatation and SCAD presenting concomitantly. This case highlights the importance of confirming the diagnosis of SCAD with intravascular imaging and of investigating for extracoronary arteriopathies.