Intracoronary imaging guidance of percutaneous coronary interventions: how and when to apply validated metrics to improve the outcome.

Percutaneous coronary intervention (PCI) is still burdened by a substantial number of complications despite constant technological advances, including the advent of intracoronary imaging (ICI) techniques. ICI modalities have been instrumental for the understanding the mechanism of PCI failure. Thanks to the ability to detail the pre-intervention coronary anatomy and identify the features indicative of sub-optimal stent deployment, ICI techniques can be utilised to improve coronary interventions in different clinical scenarios. More recently large randomized clinical trials on ICI guidance confirmed the clinical effectiveness of this approach especially in complex high-risk interventions.

Minimalistic Hybrid Approach for the Percutaneous Treatment of Coronary Chronic Total Occlusions: Midterm Follow-Up of an International Multicenter Cohort.

The minimalistic hybrid approach (MHA) is a recently proposed algorithm to perform chronic total occlusion (CTO) percutaneous coronary intervention (PCI), reducing the overall invasiveness of the procedure without impacting the acute results. However, data on midterm results are lacking. This study aimed to evaluate the midterm clinical outcomes of a multicenter international cohort of CTO PCI treated according to the MHA. Data from a consecutive series of patients with a CTO who underwent PCI according to the MHA between February 2019 and March 2022 were prospectively collected in 3 European centers and retrospectively analyzed. The main outcome was the first occurrence of a major adverse cardiac event (MACE), defined as a composite outcome of all-cause death, any myocardial infarction, and target vessel revascularization, at the last follow-up available. A total of 212 patients were included. The majority of the patients were symptomatic for angina (Canadian Cardiovascular Society class 2 or 3: 63.7%) at the time of the index procedure. The mean Japanese-CTO and CASTLE scores were 2.1 ± 1.2 and 2.0 ± 1.3, respectively. Technical success (CTO open with optimal flow) was achieved in 198 patients (93.9%) and procedural success (technical success without in-hospital MACEs) in 195 (91.9%). At the last follow-up available (median 677 days), the cumulative incidence rate of MACEs was 11.5%; in particular, all-cause death was 7.4%, any myocardial infarction was 4.3%, and unplanned target vessel revascularization was 6.5%. In conclusion, the midterm results of the MHA seem to be in line with contemporary results of other CTO PCI algorithms, thus potentially validating the MHA as a valuable alternative, provided that interventionalists are already expert CTO operators and accustomed to the definitions and peculiarities of MHA.

Clinical impact of OCT-derived suboptimal stent implantation parameters and definitions.

AIMS: Despite growing evidence supporting the clinical utility of optical coherence tomography (OCT) guidance during percutaneous coronary interventions (PCIs), there is no common agreement as to the optimal stent implantation parameters that enhance clinical outcome. METHODS AND RESULTS: We retrospectively examined the predictive accuracy of suboptimal stent implantation definitions proposed from the CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA studies for the long-term risk of device-oriented cardiovascular events (DoCE) in the population of large all-comers CLI-OPCI project. A total of 1020 patients undergoing OCT-guided drug-eluting stent implantation in the CLI-OPCI registry with a median follow-up of 809 (quartiles 414-1376) days constituted the study population. According to CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA criteria, the incidence of suboptimal stent implantation was 31.8%, 58.1%, and 57.8%, respectively. By multivariable Cox analysis, suboptimal stent implantation criteria from the CLI-OPCI II [hazard ratio 2.75 (95% confidence interval 1.88-4.02), P < 0.001] and ILUMIEN-IV OPTIMAL PCI [1.79 (1.18-2.71), P = 0.006] studies, but not FORZA trial [1.11 (0.75-1.63), P = 0.597], were predictive of DoCE. At long-term follow-up, stent edge disease with minimum lumen area <4.5 mm2 [8.17 (5.32-12.53), P < 0.001], stent edge dissection [2.38 (1.33-4.27), P = 0.004], and minimum stent area <4.5 mm2 [1.68 (1.13-2.51), P = 0.011] were the main OCT predictors of DoCE. CONCLUSION: The clinical utility of OCT-guided PCI might depend on the metrics adopted to define suboptimal stent implantation. Uncovered disease at the stent border, stent edge dissection, and minimum stent area <4.5 mm2 were the strongest OCT associates of stent failure.

Prediction of new onset atrial fibrillation in patients with acute coronary syndrome undergoing percutaneous coronary intervention using the C2HEST and mC2HEST scores: A report from the multicenter REALE-ACS registry.

BACKGROUND: New onset atrial fibrillation (NOAF) is associated with worse clinical outcomes after acute coronary syndrome (ACS). Identification of ACS patients at risk of NOAF remains challenging. To test the value of the simple C2HEST score for predicting NOAF in patients with ACS. METHODS: We studied patients from the prospective ongoing multicenter REALE-ACS registry of patients with ACS. NOAF was the primary endpoint of the study. The C2HEST score was calculated as coronary artery disease or chronic obstructive pulmonary disease (1 point each), hypertension (1 point), elderly (age ≥ 75 years, 2 points), systolic heart failure (2 points), thyroid disease (1 point). We also tested the mC2HEST score. RESULTS: We enrolled 555 patients (mean age 65.6 ± 13.3 years; 22.9% women), of which 45 (8.1%) developed NOAF. Patients with NOAF were older (p < 0.001) and had more prevalent hypertension (p = 0.012), chronic obstructive pulmonary disease (p < 0.001) and hyperthyroidism (p = 0.018). Patients with NOAF were more frequently admitted with STEMI (p < 0.001), cardiogenic shock (p = 0.008), Killip class ≥2 (p < 0.001) and had higher mean GRACE score (p < 0.001). Patients with NOAF had a higher C2HEST score compared with those without (4.2 ± 1.7 vs 3.0 ± 1.5, p < 0.001). A C2HEST score > 3 was associated with NOAF occurrence (odds ratio 4.33, 95% confidence interval 2.19-8.59, p < 0.001). ROC curve analysis showed good accuracy of the C2HEST score (AUC 0.71, 95%CI 0.67-0.74) and mC2HEST score (AUC 0.69, 95%CI 065-0.73) in predicting NOAF. CONCLUSIONS: The simple C2HEST score may be a useful tool to identify patients at higher risk of developing NOAF after presentation with ACS.

Optical coherence tomography-derived lipid core burden index and clinical outcomes: results from the CLIMA registry.

AIMS: The aim of this study was to assess the morphological characteristics and prognostic implications of the optical coherence tomography (OCT)-derived lipid core burden index (LCBI). METHODS AND RESULTS: OCT-LCBI was assessed in 1003 patients with 1-year follow-up from the CLIMA multicentre registry using a validated software able to automatically obtain a maximum OCT-LCBI in 4 mm (maxOCT-LCBI4mm). Primary composite clinical endpoint included cardiac death, myocardial infarction, and target-vessel revascularization. A secondary analysis using clinical outcomes of CLIMA study was performed. Patients with a maxOCT-LCBI4mm ≥ 400 showed higher prevalence of fibrous cap thickness (FCT) <75 µm [odds ratio (OR) 1.43, 95% confidence interval (CI) 1.03-1.99; P = 0.034], lipid pool arc >180° (OR 3.93, 95%CI 2.97-5.21; P < 0.001), minimum lumen area <3.5 mm2 (OR 1.5, 95%CI 1.16-1.94; P = 0.002), macrophage infiltration (OR 2.38, 95%CI 1.81-3.13; P < 0.001), and intra-plaque intimal vasculature (OR 1.34, 95%CI 1.05-1.72; P = 0.021). A maxOCT-LCBI4mm ≥400 predicted the primary endpoint [adjusted hazard ratio (HR) 1.86, 95%CI 1.1-3.2; P = 0.019] as well as the CLIMA endpoint (HR 2.56, 95%CI 1.24-5.29; P = 0.011). Patients with high lipid content and thin FCT < 75 µm were at higher risk for adverse events (HR 4.88, 95%CI 2.44-9.72; P < 0.001). CONCLUSIONS: A high maxOCT-LCBI4mm was related to poor outcome and vulnerable plaque features. This study represents a step further in the automated assessment of the coronary plaque risk profile.

Sex-specific features of optical coherence tomography detected plaque vulnerability related to clinical outcomes: insights from the CLIMA study.

PURPOSE: To investigate the different impact of optical coherence tomography (OCT)-derived vulnerable plaque features on future adverse events (AEs) according to the biological sex. METHODS: The prospective multicenter CLIMA study (ClinicalTrials.gov: NCT02883088) enrolled 1003 patients with OCT plaque analysis of non-treated coronary plaques located in the proximal left anterior descending artery. Sex-specific differences in plaque composition and vulnerable features were described. We investigated the incidence of AEs, including cardiac death, any myocardial infarction and target vessel revascularization at 1-year. RESULTS: Among 1003 patients, 24.6% were women. Women were older and more frequently affected by chronic kidney disease. Dyslipidemia, prior MI and smoking habit were more common in men. At OCT analysis, women had shorter plaque length (p < 0.001), ticker fibrous cap (p = 0.001), smaller maximum lipid arc (p = 0.019), lower macrophage infiltration (p < 0.001) and intra-plaque layered tissue (p = 0.007). During follow-up, 65 AEs were registered. The presence of a thin fibrous cap and a large macrophage infiltration (> 67°) predicted AEs in both sexes. The presence of macrophages (HR 3.38, p = 0.018) and a small minimum lumen area (HR 4.97, p = 0.002) were associated with AEs in women but not in men, while a large lipid arc (> 180°) was associated with AEs in men (HR 2.56, p = 0.003) but not in women. CONCLUSION: This subanalysis of the CLIMA study investigated for the first-time sex-specific OCT features of plaque vulnerability associated with AEs. Local inflammation was associated with AEs in women and a large lipid arc was predictive in men. OCT may help develop sex-specific risk stratification strategies.

[From regression to stabilization: new insights into the evolution of coronary atherosclerotic plaque]. / Dalla regressione alla stabilizzazione: l'evoluzione della placca aterosclerotica coronarica secondo le nuove evidenze.

Coronary artery atherosclerosis is a constantly evolving disease. Over the years, new drug therapies have been shown to reduce adverse cardiovascular events and improve the survival of patients with coronary artery disease. New intracoronary imaging modalities, including intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have been introduced to detect the anatomic changes which follow an effective lipid-lowering therapy in human coronary plaques. Particularly, the use of optical coherence tomography made it possible to evaluate plaque composition and showed how an intensive lipid-lowering therapy can stabilize atherosclerosis by improving vulnerable plaque features. Future non-invasive applications are required for large-scale use of these findings.

The Role of the Association Between Serum C-Reactive Protein Levels and Coronary Plaque Macrophage Accumulation in Predicting Clinical Events - Results from the CLIMA Registry.

The present investigation aims to study the interaction between systemic and intra-plaque inflammation in predicting cardiac events. We investigated C-reactive protein (CRP) levels as well as plaque inflammation with optical coherence tomography (OCT)-detected macrophages in the CLIMA study. 689 patients had admission CRP serum values reported, and high CRP values were defined as ≥ 2 mg/dl. The main study endpoint was a composite of cardiac death, myocardial infarction, and/or target vessel revascularization at 1-year follow-up. At multivariate Cox regression analysis, a large (hazard ratio [HR] 2.27, 95% confidence interval [CI] 1.2-4.3; p = 0.013) and superficial (HR 2.78, 95%CI 1.5-5.1; p = 0.001) macrophage arc was predicted of the main composite endpoint in patients with high CRP levels. Patients with large/superficial macrophage accumulation and low CRP levels were not at higher risk of adverse events. The presence of high CRP levels and large/superficial macrophage accumulation at OCT analysis identified patients at higher risk of clinical events.

The double injection technique to improve visualization of severe coronary lesions with optical coherence tomography.

BACKGROUND: Optical coherence tomography (OCT) is a high-resolution imaging modality that provides a precise evaluation of coronary anatomy. However, the presence of severe coronary lesions can prevent the required adequate distal contrast flushing resultting in inadequate blood clearance and poor image quality or complete blood shadowing of the underlying vessel wall. OBJECTIVES: The aim of this prospective study was to evaluate the feasibility and safety of a novel "double injection technique" (DIT) to overcome the limitations of the conventional technique (CT) in patients with severely stenotic lesions. METHODS: Twenty-three patients with severe angiographic lesions were sequentially imaged before intervention with OCT with the CT and then with DIT. A total of 5125 OCT frames were carefully matched and analyzed by an independent central core lab. A semiquantitative image quality score was used to grade the number of quadrants (0-4) with vessel wall visualization. RESULTS: Optimal OCT visualization (Grades 3-4) significantly improved by the DIT (68% vs. 38% of frames, p < 0.001). The DIT also improved the mean score (3.1 ± 0.6 vs. 2.0 ± 0.8; p < 0.05; mean improvement of 1.1 ± 0.5 per patient). There were no complications associated with the DIT. CONCLUSION: The DIT significantly improved preintervention image quality of OCT in severe coronary lesions.

Balloon aortic valvuloplasty review: the revenge during COVID-19 outbreak?

Aortic stenosis is a highly prevalent cardiac valvular disease in adult population and increases with age. After symptoms onset in severe aortic stenosis, the prognosis begins to decline; however, new studies demonstrate an increased risk of death in patients with moderate disease. Although majority of patients with severe aortic stenosis are treated electively with surgical or transcatheter aortic valve replacement, not all patients are candidates for the interventions. Balloon aortic valvuloplasty can be used successfully as a bridge to definitive treatment or as palliative therapy in patients who are not candidates for either procedure. In this paper, we discuss and justify the current indications and contraindications for balloon aortic valvuloplasty. Additionally, the step-by-step procedure technique and most frequent complications are described. Moreover, we presented the safety and feasibility of balloon aortic valvuloplasty in 33 consecutive patients on a waiting list for transcatheter aortic valve replacement at 3 expert Italian centers during the first and second waves of COVID-19, when clinical priorities focused on hospitalized patients with pneumonia. The procedural success in this cohort of patients was achieved in 31 patients (94%). Out of the 33 patients enrolled, 15 underwent TAVR within 5±2 months from the valvuloplasty, and at 6-month follow-up a total of 2 patients died for end-stage heart failure.

Relationship betweeen the amount and location of macrophages and clinical outcome: subanalysis of the CLIMA-study.

BACKGROUND: The ability of optical coherence tomography (OCT) to recognize intraplaque macrophage infiltration is now well acknowledged. This post-hoc analysis of the CLIMA study aimed to address the clinical impact of the circumferential extension of OCT-defined macrophages and their location at one year follow-up. METHODS: The multicentre CLIMA study enrolled 1003 patients undergoing OCT evaluation of the untreated proximal left anterior descending (LAD) coronary artery. Measurements of circumferential extension of macrophages and measurements of the distance from intima-lumen contour to macrophages string were performed at the plaque cross-section judged as containing the greatest amount of macrophages. The main study endpoint was a composite of cardiac death, myocardial infarction (MI) and/or target vessel revascularization (TVR). RESULTS: Patients with large macrophage arc (p = 0.001) and superficial macrophage arc (p < 0.001) showed a higher one-year incidence of the main one-year composite endpoint. Consistently hypertension (p = 0.018), family history of CAD (p = 0.046), diabetes mellitus (p = 0.036), lower ejection fraction (p = 0.009) and chronic kidney disease (p = 0.019) were more frequently found in patients experiencing the main composite endpoint. At multivariate Cox regression analysis, fibrous cap thickness < 75 µm (HR 2.51, 95% 1.46-4.32), presence of large (HR 1.97, 95%CI 1.16-3.35, p = 0.012) and superficial (HR 1.72, 95%CI 1.02-2.90; p = 0.040) macrophage arc remained independent predictors of the main composite endpoint. Large macrophage arc was associated with target LAD related MI. CONCLUSION: The present post-hoc analysis of the CLIMA showed that the circumferential extension of macrophages and their location are related to a composite endpoint of cardiac death, MI and/or TVR.

Clinical outcomes of suboptimal stent deployment as assessed by optical coherence tomography: long-term results of the CLI-OPCI registry.

BACKGROUND: Intraprocedural optical coherence tomography (OCT) is a valuable tool for guidance of percutaneous coronary intervention, but long-term follow-up data are lacking. AIMS: The aim of this study was to address the long-term (7.5 years) clinical impact of quantitative OCT metrics of suboptimal stent implantation. METHODS: This retrospective study includes 391 patients with long-term follow-up (mean 2,737 days; interquartile range 1,301-3,143 days) from the multicentre Centro per la Lotta contro l'Infarto - Optimisation of Percutaneous Coronary Intervention (CLI-OPCI) registry. OCT-assessed suboptimal stent deployment required the presence of at least one of the following pre-defined OCT findings: in-stent MLA <4.5 mm2, proximal or distal reference lumen narrowing with lumen area <4.5 mm2, significant proximal or distal edge dissection width ≥200 µm. RESULTS: One hundred and two patients (26.1%) with 138 stented lesions (27.7%) experienced a device-oriented cardiovascular event (DOCE). In-stent MLA <4.5 mm2 (38.1% vs 19.8%, p<0.001), in-stent lumen expansion <70% (29.5% vs 20.3%, p=0.032), proximal reference lumen narrowing <4.5 mm2 (6.5% vs 1.4%, p=0.004), and distal reference lumen narrowing <4.5 mm2 (12.9% vs 3.6%, p=0.001) were significantly more common in the DOCE vs non-DOCE group. OCT-assessed suboptimal stent deployment was an independent predictor of long-term DOCE (HR 2.17, p<0.001), together with bare metal stent implantation (HR 1.73, p=0.003) and prior revascularisation (HR 1.53, p=0.017). CONCLUSIONS: The presence of OCT-assessed suboptimal criteria for stent implantation was related to a worse clinical outcome at very long-term follow-up. This information further supports an OCT-guided strategy of stent deployment.

Impact of environmental pollution and weather changes on the incidence of ST-elevation myocardial infarction.

BACKGROUND: Environmental pollution and weather changes unfavorably impact on cardiovascular disease. However, limited research has focused on ST-elevation myocardial infarction (STEMI), the most severe yet distinctive form of acute coronary syndrome. METHODS AND RESULTS: We appraised the impact of environmental and weather changes on the incidence of STEMI, analysing the bivariate and multivariable association between several environmental and atmospheric parameters and the daily incidence of STEMI in two large Italian urban areas. Specifically, we appraised: carbon monoxide (CO), nitrogen dioxide (NO2), nitric oxide (NOX), ozone, particulate matter smaller than 10 µm (PM10) and than 2.5 µm (PM2.5), temperature, atmospheric pressure, humidity and rainfall. A total of 4285 days at risk were appraised, with 3473 cases of STEMI. Specifically, no STEMI occurred in 1920 (44.8%) days, whereas one or more occurred in the remaining 2365 (55.2%) days. Multilevel modelling identified several pollution and weather predictors of STEMI. In particular, concentrations of CO (p = 0.024), NOX (p = 0.039), ozone (p = 0.003), PM10 (p = 0.033) and PM2.5 (p = 0.042) predicted STEMI as early as three days before the event, as well as subsequently, and NO predicted STEMI one day before (p = 0.010), as well as on the same day. A similar predictive role was evident for temperature and atmospheric pressure (all p < 0.05). CONCLUSIONS: The risk of STEMI is strongly associated with pollution and weather features. While causation cannot yet be proven, environmental and weather changes could be exploited to predict STEMI risk in the following days.

Present and future of coronary risk assessment.

The search for subclinical atherosclerosis is carried out in several arterial districts using ultrasonography and computed tomography (CT). Coronary calcium assessed by computerized tomography (calcium score) is a well-validated marker of atherosclerosis and able to correlate with the extent of coronary artery disease and the risk of cardiovascular events. The evaluation of carotid atherosclerosis by ultrasonography is a technically simple and low-cost solution. However, the literature does not provide a sufficient number of evidence to clarify the clinical impact of carotid atherosclerosis and in particular the risk of developing cardiac events. According to the researchers of the Progression of Early Subclinical Atherosclerosis (PESA) study, subclinical atherosclerosis research should preferably be carried out in the femoral district, which is more easily affected by atherosclerosis. Pending the data from the PESA study, which will better clarify the role of ultrasound applied in non-coronary districts, the coronary calcifications seems to be a reasonable solution. It is possible that in the future imaging techniques (CT-PET) capable of studying the extent and functional status of coronary atherosclerosis will further improve the identification of the risk of cardiovascular events.

Adoption of a new automated optical coherence tomography software to obtain a lipid plaque spread-out plot.

PURPOSE: Near infrared spectroscopy-Intravascular ultrasound (NIRS-IVUS) provide a fully automated Lipid Core Burden Index (LCBI). Optical coherence tomography (OCT) is potentially capable of measuring lipid longitudinal extension in a dedicated two-dimensional LCBI spread-out plot. The present study has been designed to validate an automated approach to assess OCT images, able of providing a dedicated LCBI spread-out plot. METHODS: We compared results obtained with conventional (manual) OCT, with those obtained with a novel automated OCT algorithm and with NIRS-IVUS in consecutive 40 patients. Our goal was to calculate the lipid core longitudinal extension in a dedicated two-dimensional LCBI spread-out plot. Three groups were identified according to the studied lesions: (1) culprit lesions in ACS patients (n = 16), (2) non-culprit lesions in ACS patients (n = 12) and (3) lesions in stable patients (n = 12). OCT (either manual and automated) and NIRS-IVUS assessment showed for culprit ACS plaques a more complex anatomy. RESULTS: A strong trend for increased LCBI was found in the culprit ACS group, regardless of the adopted imaging modality (either NIRS-IVUS or automated OCT). A fair correlation was obtained for the maximum 4 mm LCBI measured by NIRS-IVUS and automated OCT (r = 0.75). The sensitivity and specificity of automated OCT to detect significant LCBI (> 400) were 90.5 and 84.2 respectively. CONCLUSION: We developed an OCT automated approach that can provide a dedicated lipid plaque spread-out plot to address plaque vulnerability. The automated OCT software can promote and improve OCT clinical applications for the identification of patients at risk of hard events.

Prevalence and quantitative assessment of macrophages in coronary plaques.

Although optical coherence tomography (OCT) proved to be able to identify macrophage clusters, there are no available data on the possibility to obtain reproducible measurements of their circumferential extension and location. The purpose of the present post-hoc analysis of the CLIMA study was to revise the clinical and demographic variables of patients having coronary plaques with macrophages and to investigate the reproducibility of their quantitative assessment. A total of 577 patients out of 1003 undergoing OCT showed macrophage accumulation. Three groups were identified; group 1 (426 patients) without macrophages, group 2 (296) patients with low macrophage content (less than median value [67°] of circumferential arc) and group 3 (281) with high macrophage content arc [> 67°]. Patients with macrophages (groups 2 and 3) showed a higher prevalence of family history for coronary artery disease and hypercholesterolemia and had a significantly larger body mass index. Furthermore, group 3 had more commonly triple vessel disease and higher value of LDL cholesterol levels compared to the two other groups. The inter-observer agreement for macrophage interpretation was good: R values were 0.97 for the circumferential arc extension, 0.95 for the minimum distance and 0.98 for the mean distance. A non-significant correlation between circumferential extension of macrophages and hsCRP values was found (R = 0.013). Quantitative assessment of macrophage accumulations can be obtained with high reproducibility by OCT. The presence and amount of macrophages are poorly correlated with hsCRP and identify patients with more advanced atherosclerosis and higher LDL cholesterol levels.

Impact of prior coronary artery bypass grafting in patients undergoing chronic total occlusion-percutaneous coronary intervention: Procedural and clinical outcomes from the REgistry of Crossboss and Hybrid procedures in FrAnce, the NetheRlands, BelGium, and UnitEd Kingdom (RECHARGE).

AIM: Chronic total occlusions (CTO) in patients with history of coronary artery bypass graft (CABG) show more advanced and complex atherosclerotic pathology. Aim of our study is to compare outcomes in patients undergoing CTO percutaneous coronary intervention (PCI) with previous CABG versus those without in the REgistry of Crossboss and Hybrid procedures in FrAnce the NetheRlands, BelGium and UnitEd Kingdom (RECHARGE). METHODS & RESULTS: The RECHARGE cohort (1,252 patients) was divided in two groups according to the presence of previous CABG (217) or not. We also focused, in the post-CABG group, on a comparison between CTO in previously grafted vessels versus non-grafted vessels. The CTO complexity scores were higher and the success rate (71.9% vs. 88.7%, p < .001) was lower in the CABG group, this difference was driven by higher failure rates in high-complexity-score CTO. The rate of in-hospital complications was similar. In the post-CABG group, the procedural success of CTO located in previously grafted vessels versus those in vessels not previously grafted, was comparably suboptimal (73.1% vs. 68%, p = .47). CONCLUSION: Patients undergoing CTO PCI with prior CABG have a higher prevalence of comorbidities and more complex lesion characteristics. In the post-CABG population the success rate was significantly lower, particularly in high CTO complexity scores, though complication rates were comparable. In the post-CABG population, the CTO success rate was independent of the presence of a previous graft on the CTO vessel.

Chronic total occlusion techniques in non-chronic total occlusion cases, the wealth of a large toolbox.

The development of dedicated expertise in chronic total occlusion (CTO) percutaneous coronary interventions (PCI) techniques is a time-consuming process that makes the CTO-operator more versatile and resolute in routine PCI. We describe three characteristic cases where the use of a specific CTO-technique was applied in the setting of complicated PCI to prevent a "nightmare" in the catheterisation laboratory. More specifically, management of occlusive dissections was successfully mastered with a retrograde technique in the first case, with a sub-intimal transcatheter withdrawal technique in the second one and with an antegrade dissection-re-entry technique in the last patient. In all the described cases, the adoption of these advanced techniques would have been substantially unfeasible for non-CTO operators or without a CTO-operator guidance. Fellows undergoing training in invasive cardiology should be encouraged to enrol in a CTO programme for at least part of their fellowship in order to become acquainted to these CTO techniques.