Assessment of Myocardial Viability and Risk Stratification in Coronary Chronic Total Occlusion: A Qualitative and Quantitative Stress Cardiac MRI Study.

BACKGROUND: Indicators for assessing myocardial viability and risk stratification in patients with coronary chronic total occlusion (CTO) are still in the research stage. PURPOSE: To use stress-MRI to assess myocardial function, blood perfusion, and viability and to explore their relationship with collateral circulation. STUDY TYPE: Prospective. SUBJECTS: Fifty-one patients with CTO in at least one major artery confirmed by X-ray coronary angiography (male: 46; age 55.2 ± 10.8 years). FIELD STRENGTH/SEQUENCE: 3.0T; TurboFlash, balanced steady-state free precession cine, and phase-sensitive inversion recovery sequences. ASSESSMENT: Stress-MRI was used to obtain qualitative and quantitative parameters of segmental myocardium. Myocardial segments supplied by CTO target vessels were grouped according to the degree of collateral circulation assessed by radiographic coronary angiography (no/mild, moderate, or good). Depending on qualitative stress perfusion assessment and late gadolinium enhancement (LGE) extent, segments were also categorized as negative, viable, or trans-infarcted. STATISTICAL TESTS: Independent sample Student's t-test, one-way analysis of variance (ANOVA) test, Mann-Whitney U test, Kruskal-Wallis test, Spearman correlation coefficient (r). P < 0.05 was considered statistically significant. RESULTS: A total of 334 segments were supplied by CTO target vessels. The radial strain (RS), circumferential strain (CS), longitudinal strain (LS) of the negative, viable, and trans-infarcted regions showed a significant and stepwise impairment. Myocardial blood flow at rest was positively correlated with RS, CS, and LS (r = 0.42, 0.43, 0.38, respectively). Among the different collateral circulation, there were no significant differences in RS, CS, LS, and LGE volume (P = 0.788, 0.562, 0.122, 0.170, respectively), and there were also no statistically significant differences in the proportions of negative, viable, and trans-infarcted regions (P = 0.372). DATA CONCLUSION: Myocardial perfusion obtained by stress-MRI combined with strain and LGE may comprehensively evaluate myocardial function and viability, and has potential to facilitate risk stratification of CTO. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.

Accuracy of the Euro CTO(CASTLE) score obtained on coronary computed tomography angiography for Predicting 30-minute wire crossing in chronic total occlusions.

BACKGROUND: To investigate the feasibility and accuracy of the Euro CTO (CASTLE)CTA score obtained on coronary computed tomography angiography (CCTA) for predicting the success of percutaneous coronary intervention (PCI) and the 30-min wire crossing in chronic total occlusions (CTO). METHOD: One hundred and fifty patients (154 CTO cases; median age, 61 (interquartile range [IQR], 54-68) years; 75.3% male) received CCTA at the People's Hospital of Liaoning Provincce within 1 month before the procedure. The Euro CTO (CASTLE) score obtained on CCTA(CASTLECTA) was calculated and compared with the Euro CTO (CASTLE) score obtained based on coronary angiography (CASTLECAG) for the predictive value of 30-min wire crossing and CTO procedural success. RESULTS: In our study, the CTO-PCI success rate was 89.0%, with guidewires of 65 cases (42.2%) crossing within 30 min. There were no significant differences in the median CASTLECTA and CASTLECAG scores in the procedure success group (3 [IQR, 2-4] vs 3 (IQR, 2-3]; p = 0.126). However, the median CASTLECTA score was significantly higher than the median CASTLECAG score in the procedure failure group (4 [IQR, 3-5.5] vs 4 [IQR, 2.5-5.5]; p = 0.021). There was no significant difference between the median CASTLECTA score and the median CASTLECAG score in the 30-min wire crossing failure group (3 [IQR, 3-4] vs 3 [IQR, 2-4]; p = 0.254). However, the median CASTLECTA score was significantly higher than the median CASTLECAG score in the 30-min wire crossing group (3 [IQR, 2-3] vs 2 [IQR, 2-3]; p < 0.001). The CASTLECTA score described higher levels of calcification than the CASTLECAG score (48.1% vs 33.8%; p = 0.015). There was no significant difference between the CASTLECTA score (area under the curve [AUC], 0.643; 95% confidence interval [CI], 0.561-0.718) and the CASTLECAG score (AUC, 0.685; 95% CI, 0.606-0.758) for predicting procedural success (p = 0.488). The CASTLECTA score (AUC, 0.744; 95% CI, 0.667-0.811) was significantly better than the CASTLECAG score (AUC, 0.681; 95% CI, 0.601-0.754; p = 0.046) for predicting 30-min wire crossing with the best cut-off value being CASTLECTA ≤ 3. The sensitivity, specificity, positive predictive value, and negative predictive value were 90.8%, 55.2%, 54.6%, and 87.0%, respectively. CONCLUSION: The CASTLECTA scores obtained from noninvasive CCTA perform better for the prediction of the 30-min wire crossing than the CASTLECAG score.

Excimer laser coronary atherectomy for uncrossable coronary lesions. A multicenter registry.

OBJECTIVES: To assess the efficacy and safety of excimer laser coronary atherectomy (ELCA), as well as, the long-term outcomes and the factors associated with ELCA failure in uncrossable lesions. BACKGROUND: Uncrossable lesions constitute a challenge for percutaneous coronary intervention. METHODS: This multicenter registry included 126 patients with 126 uncrossable lesions. Study endpoints were ELCA success, technical success and a composite of cardiac death, myocardial infarction (MI), and target-lesion revascularization (TLR) on follow-up. Predictors of ELCA failure were analyzed. RESULTS: Moderate or severe calcification was present in 79 (62.7%) of the lesions and 58 (46%) were a chronic total occlusion. ELCA success was obtained in 103 (81.8%) patients. Rotational atherectomy was attempted as bailout in 21 out of 23 ELCA failure (91.3%), being successful in 14 (66.7%) of them. Finally, technical and procedural success were achieved in 114 (90.5%) and 110 (87.3%) of the patients. Severe calcification was independently associated with ELCA failure (OR: 3.73, 95% CI: 1.35-10.32; p = .011). Two (1.6%) patients died (one after a stroke and another patient because of heart failure), 4 (3.2%) developed a non-Q MI without clinical consequences and 1 (0.8%) patient had a Q-MI. Other complications were ventricular tachycardia/fibrillation (n = 2; 1.6%) and flow-limiting dissection (n = 1, 0.8%). At follow-up (median 424 days), 3 (2.4%) patients died (1 (0.8%) from cardiovascular cause) and 15 (11.9%) required TLR. CONCLUSIONS: In our multicenter experience, ELCA use demonstrated to be safe and reasonably effective with a rate of events on follow-up relatively low. Severe calcification was associated with ELCA failure.

A computed tomography algorithm for crossing coronary chronic total occlusions: riding on the wave of the proximal cap and distal vessel segment.

With wider adoption of coronary computed tomography angiography (coronary CTA), chronic total occlusions (CTOs) are being increasingly identified and characterised by non-invasive angiography. In particular, the ability of coronary CTA to clearly delineate atherosclerotic plaque, as well as to display three-dimensional vessel trajectories, has garnered particular attention in the context of preprocedural planning and periprocedural guidance of CTO percutaneous coronary intervention (PCI). Single CTO features and combined scoring systems derived from CTA (mostly exceeding the diagnostic performance of the angiographic J­CTO score) have been used to predict time-efficient guidewire crossing, and thus grade the CTO difficulty level prior to PCI. In addition, the introduction of three-dimensional CTA/fluoroscopy co-registration for periprocedural navigation during CTO PCI offers the unprecedented opportunity to resolve proximal cap ambiguity and clearly visualise the distal CTO segment, thereby potentially influencing CTO PCI strategies and techniques. In this review, the potential advantages of non-invasive evaluation of CTO by coronary CTA are described, and a CTA-based hybrid algorithm is introduced for further enhancing the efficiency of CTO PCI. Further studies are clearly needed to verify the proposed approach. However, several luminary operators have already implemented coronary CTA for planning and periprocedural guidance of CTO interventions using the hybrid algorithm.

Interplay of TNF-α, soluble TNF receptors and oxidative stress in coronary chronic total occlusion of the oldest patients with coronary heart disease.

BACKGROUND: The interplay of tumour necrosis factor-α (TNF-α) and oxidative stress was related to severities of coronary atherosclerosis and congestive heart failure. We tried to identify TNF-α, soluble tumour necrosis factor-α receptor-1 (sTNFR-1), soluble tumour necrosis factor-α receptor-2 (sTNFR-2) and oxidative stress as potential non-invasive diagnostic and therapeutic biomarkers for coronary chronic total occlusion (CCTO) in the oldest patients with coronary heart disease (CHD). METHODS: We determined the expression levels of TNF-α, sTNFR-1, sTNFR-2, oxidative stress biomarkers (malondialdehyde [MDA], aldosterone [ALD], angiotensin II [Ang II], and high sensitivity C-reactive protein [hs-CRP]) in oldest patients with CCTO. RESULTS: The levels of TNF-α, sTNFR-1, sTNFR-2, MDA, ALD, Ang II and hs-CRP were increased in oldest patients with CCTO (P < 0.001). The CCTO of oldest patients with CHD may involve the interplay of TNF-α, sTNFR-1, sTNFR-2 and oxidative stress. CONCLUSIONS: The TNF-α, sTNFR-1, sTNFR-2 and oxidative stress could be considered as potential non-invasive diagnostic and therapeutic biomarkers for CCTO in the oldest patients with CHD.

Hybrid PET/MR imaging for the prediction of left ventricular recovery after percutaneous revascularisation of coronary chronic total occlusions.

PURPOSE: To evaluate myocardial viability assessment with hybrid 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/magnetic resonance imaging ([18F]FDG-PET/MR) in predicting left ventricular (LV) wall motion recovery after percutaneous revascularisation of coronary chronic total occlusion (CTO). METHODS AND RESULTS: Forty-nine patients with CTO and corresponding wall motion abnormality (WMA) underwent [18F]FDG-PET/MR imaging for viability assessment prior to percutaneous revascularisation. After 3-6 months, 23 patients underwent follow-up MR to evaluate wall motion recovery. In total, 124 segments were assigned to the CTO territories, while 80 segments displayed impaired wall motion. Of these, 68% (54) were concordantly viable in PET and MR; conversely, only 2 segments (2%) were assessed non-viable by both modalities. However, 30% showed a discordant viability pattern, either PET non-viable/MR viable (3 segments, 4%) or PET viable/MR non-viable (21 segments, 26%), and the latter revealed a significant wall motion improvement at follow-up (p = 0.033). Combined imaging by [18F]FDG-PET/MR showed a fair accuracy in predicting myocardial recovery after CTO revascularisation (PET/MR area under ROC curve (AUC) = 0.72, p = 0.002), which was superior to LGE-MR (AUC = 0.66) and [18F]FDG-PET (AUC = 0.58) alone. CONCLUSION: Hybrid PET/MR imaging prior to CTO revascularisation predicts more accurately the recovery of dysfunctional myocardium than PET or MR alone. Its complementary information may identify regions of viable myocardium with increased potential for functional recovery.

Prompt and consistent improvement of coronary flow velocity reserve following successful recanalization of the coronary chronic total occlusion in patients with viable myocardium.

BACKGROUND: Coronary chronic total occlusion (CTO) is characterized by the presence of collateral blood vessels which can provide additional blood supply to CTO-artery dependent myocardium. Successful CTO recanalization is followed by significant decrease in collateral donor artery blood flow and collateral derecruitment, but data on coronary hemodynamic changes in relation to myocardial function are limited. We assessed changes in coronary flow velocity reserve (CFVR) by echocardiography in collateral donor and recanalized artery following successful opening of coronary CTO. METHODS: Our study enrolled 31 patients (60 ± 9 years; 22 male) with CTO and viable myocardium by SPECT scheduled for percutaneous coronary intervention (PCI). Non-invasive CFVR was measured in collateral donor artery before PCI, 24 h and 6 months post-PCI, and 24 h and 6 months in recanalized artery following successful PCI of CTO. RESULTS: Collateral donor artery showed significant increase in CFVR 24 h after CTO recanalization compared to pre-PCI values (2.30 ± 0.49 vs. 2.71 ± 0.45, p = 0.005), which remained unchanged after 6-months (2.68 ± 0.24). Baseline blood flow velocity of the collateral donor artery significantly decreased 24 h post-PCI compared to pre-PCI (0.28 ± 0.06 vs. 0.24 ± 0.04 m/s), and remained similar after 6 months, with no significant difference in maximum hyperemic blood flow velocity pre-PCI, 24 h and 6 months post-PCI. CFVR of the recanalized coronary artery 24 h post-PCI was 2.55 ± 0.35, and remained similar 6 months later (2.62 ± 0.26, p = NS). CONCLUSIONS: In patients with viable myocardium, prompt and significant CFVR increase in both recanalized and collateral donor artery, was observed within 24 h after successful recanalization of CTO artery, which maintained constant during the 6 months. TRIAL REGISTRATION: ClinicalTrials.gov (Number NCT04060615 ).

Late potentials abolition reduces ventricular tachycardia recurrence after ablation especially in higher-risk patients with a chronic total occlusion in an infarct-related artery.

INTRODUCTION: Late potentials (LP) abolition is recognized as an effective strategy for substrate ablation of ventricular tachycardia (VT). The presence of a chronic total occlusion in a coronary artery responsible for a previous myocardial infarction (infarct related artery CTO, IRA-CTO) is emerging as a predictor of ventricular arrhythmias and VT recurrence after ablation. We sought to analyze the effects of LP abolition, focusing on the high-risk subgroup of patients with IRA-CTO. METHODS AND RESULTS: This was a single-center, observational study that screened all patients with prior myocardial infarction and clinical VT, referred for VT ablation at San Raffaele Hospital between 2010 and June 2013. Patients were then included in the study if they had a coronary diagnostic angiography (without revascularization) performed during the index hospitalization. The main endpoint was VT recurrence after ablation. Eighty-four patients formed the population of the study. An IRA-CTO was present in 47 patients (56%) and the presence of an IRA-CTO was a predictor of VT recurrence (HR 3.7, P = 0.005). LP were observed in 51 patients and successfully abolished in 38 cases. LP abolition was associated with lower VT recurrence especially among patients with IRA-CTO (24% vs. 65%, P = 0.005). The presence of an IRA-CTO, in combination with no LP abolition, was the strongest predictor of VT recurrence (HR 4.4, P < 0.001). CONCLUSIONS: Late potentials abolition is an effective strategy for substrate ablation of ventricular tachycardia. The additional reduction of VT recurrence achieved with LP abolition on top of noninducibility is especially significant among high-risk patients with IRA-CTO.

The trap and occlude technique for retrograde wire externalization during chronic total occlusion revascularization.

Different strategies of retrograde approach were introduced in recent years to improve the success rate of percutaneous coronary intervention for coronary chronic total occlusions. The aim of this report is to describe a new technique, called "Trap and Occlude Technique," for retrograde wire externalization during CTO percutaneous revascularization. This technique may save time and reduce radiation exposure and procedure-related bleeding.

Bivalirudin in percutaneous coronary intervention for chronic total occlusion: A single-center pilot study.

BACKGROUND: Bivalirudin has been reported to be an alternative to unfractionated heparin (UFH) for anticoagulation during percutaneous coronary intervention (PCI) and associated with less bleeding risk. However, the feasibility of bivalirudin during PCI of chronic total occlusion lesions (CTO) remains unknown. OBJECTIVE: To evaluate the efficacy and safety of bivalirudin versus UFH in CTO PCI. METHODS: In this prospective and randomized controlled trial in single center, CTO patients with high bleeding risk were randomized to treatment with bivalirudin (bolus 0.75 mg/kg followed by infusion of 1.75, extra bolus 0.3 mg/kg before stenting) or UFH (100 IU/kg). The primary efficacy end point was the incidence of major adverse cardiac events (MACEs, composite of all-cause mortality, cardiac death, stent thrombosis, periprocedural myocardial infarction, or additional unplanned target lesion revascularization, or any other post-PCI ischemic event) in-hospital, and at 1-year follow-up. The primary safety end point was the occurrence of any bleeding or entry-site complications after PCI. RESULTS: A total of 84 high bleeding risk patients undergoing PCI for CTO lesions were enrolled. The baseline characteristics were similar in both treatment arms. In hospital MACEs rates were 21.4% in the bivalirudin group and 14.3% in the UFH group (P = 0.393). During 1-year's follow-up, end points did not significantly differ between the groups either. Occurrence of the major bleeding events were 4.8% in the bivalirudin group and 9.5% in the UFH group (P = 0.676). No entry-site complication was observed. CONCLUSION: In CTO patients at high risk for bleeding undergoing PCI, our data indicates that bivalirudin appears to be at least comparable in efficacy and safety to UFH. A larger clinical trial should be designed to further elucidate its efficacy and safety.

Revascularization vs. Medical Therapy for Coronary Chronic Total Occlusions in Patients With Chronic Kidney Disease.

BACKGROUND: We investigated whether the outcome of revascularization differed from the outcome of medical therapy in chronic kidney disease (CKD) and non-CKD patients with chronic total occlusion (CTO).Methods and Results:A total of 2,010 patients with CTO who underwent revascularization (n=1,355), including percutaneous coronary intervention (n=878) and coronary artery bypass grafting (n=477), or had medical therapy alone (n=655) were examined. The primary outcome was all-cause death during follow-up. Among the non-CKD patients (n=1,679), revascularization had a lower incidence of all-cause death (adjusted hazard ratio [HR] 0.54, 95% confidence interval [CI] 0.41-0.72, P<0.001) compared with medical therapy. Among the CKD patients (n=331), the difference in the incidence of all-cause death was not as marked between the 2 treatments (adjusted HR 0.71, 95% CI 0.48-1.06, P=0.09). There was a significant interaction between kidney function and treatment strategy (revascularization vs. medical therapy) on all-cause death (P for interaction=0.014). CONCLUSIONS: Based on the clinical outcomes, in CTO patients with preexisting CKD, revascularization via PCI or bypass surgery might not be as effective as in non-CKD patients.

Chronic total occlusion in an infarct-related coronary artery and the risk of appropriate ICD therapies.

INTRODUCTION: Risk stratification for ventricular arrhythmias in patients with ischemic cardiomyopathy needs to be improved. Coronary chronic total occlusions in an infarct-related artery (IRA-CTOs) have been associated with an increased arrhythmic risk. This study aimed to evaluate the association between IRA-CTOs and appropriate implantable cardioverter-defibrillator (ICD) therapies. METHODS AND RESULTS: Observational cohort study that included 342 patients with ischemic cardiomyopathy, an ICD implanted for primary or secondary prevention, and a coronary angiography performed shortly before ICD implantation. The ICD was implanted for primary prevention in 163 patients (48%). IRA-CTO was found in 161 patients (47%). During a median follow-up of 33 months, 41% of patients experienced at least one appropriate ICD therapy. Patients with IRA-CTO had higher proportions of appropriate ICD therapies (57% vs. 26%, P < 0.001) and appropriate ICD shocks (40% vs. 17%, P < 0.001). At multivariate Cox regression, IRA-CTO was the only variable that consistently resulted as independent predictor of appropriate ICD therapies and shocks both in the global population of the study (HR 2.3, P < 0.001 and HR 3, P < 0.001, respectively) and when analyzing separately patients with primary or secondary prevention ICD. CONCLUSIONS: IRA-CTO is an independent predictor of appropriate ICD therapies, including appropriate ICD shocks. This association is consistent across all the subgroups analyzed. Patients with IRA-CTO have a very high risk of appropriate ICD therapies. These findings may help improving risk stratification as well as the management of ventricular arrhythmias in patients with ischemic cardiomyopathy.

The Balloon-Microcatheter technique for treatment of coronary artery perforations.

Coronary perforation (CP) is a rare but potentially lethal complication of percutaneous coronary intervention (PCI). Management of CP is mainly conditioned by the extension of coronary rupture and location of the perforation. Successful treatment is highly affected by the operator's familiarity with tools and dedicated techniques to achieve prompt sealing of the disruption. We describe a "Balloon-Microcatheter" technique that may allow fast, safe, and effective management of CP with a single ≥ 6 Fr guiding catheter. © 2016 Wiley Periodicals, Inc.

The relationship between the neutrophil-lymphocyte ratio and the coronary collateral circulation in patients with chronic total occlusion.

OBJECTIVES: Previous studies showed the association between the major adverse cardiovascular outcomes and both higher neutrophil and lower lymphocyte counts. We aimed to investigate whether there is an association between the neutrophil-lymphocyte ratio (NLR) value and the development of coronary collateral circulation (CCC) in patients with coronary chronic total occlusion (CTO). METHODS: A total of 274 patients with CTO were included in this study. Patients were then classified according to their Rentrop collateral grades as either poor (Rentrop grades 0-1) or good (Rentrop grades 2-3). Clinical information and analyses of blood samples were obtained from a review of the patients' charts. RESULTS: Although there was no difference between the two groups with regard to cardiovascular risk profiles, the NLR values were significantly higher in the patients who had poorly developed CCC (2.6 ± 0.5 vs 2.2 ± 0.4, p<0.001). NLR, high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBC), age, diabetes, fasting glucose levels and body mass index were found to have univariate association with poorly developed CCC (p<0.1). In a multivariate logistic regression model, NLR (odds ratio 1.88, 95% confidence interval (CI) 1.37-2.74; p<0.001), high-sensitivity C-reactive protein and WBC were found to be the independent predictors of poor CCC. In receiver operator characteristic curve analysis, the optimal cut-off value of NLR to predict poor CCC was found as 2.17, with 77% sensitivity and 65% specificity. CONCLUSION: NLR, as a novel cardiovascular risk marker, is an important, simple and inexpensive method which can be used by the cardiologist as a screening inflammation tool to estimate the development of CCC in patients with CTO.

Incidence, Predictors, and Strategies for Retrograde Wire Tracking Failure via Poor Septal Collateral Channels in Chronic Total Occlusion.

Background: Retrograde guidewire (GW) tracking success via a poor septal collateral channel (CC) when an antegrade approach fails is crucial for successful revascularization of coronary chronic total occlusion (CTO) with poor septal CC. However, the incidence, predictors, and management strategies for retrograde GW tracking failure via poor septal CC remain unclear. Methods: In total, 122 CTO patients who underwent retrograde septal percutaneous coronary intervention (PCI) with poor CC between January 2017 and May 2022 were retrospectively analyzed. Patients were divided into the retrograde GW tracking success group (success group) and the retrograde GW tracking failure group (failure group). Clinical and angiographic data were compared to investigate the predictors of retrograde GW tracking failure. Results: The incidence of GW tracking failure was 22.1% (27/122). Patients in the failure group had a higher prevalence of left anterior descending artery (LAD) CTO (66.7% vs 37.9%; p = 0.009) and a higher incidence of well-developed non-septal collateral (66.7% vs 30.5%; p = 0.001). Patients with a septal CC diameter ≥ 1 mm (48.1% vs 70.5%; p = 0.040), ≥ 3 septal CCs (44.4% vs 66.3%; p = 0.046), and initial retrograde application of Guidezilla (37.0% vs 60.0%; p = 0.048) were significantly lower in the failure group than in the success group. The binary logistics regression model showed that a CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors for GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC. Conclusion: The success rate of retrograde GW tracking via poor septal CC was high, with a relatively high procedural success rate. A CC diameter < 1 mm, well-developed non-septal collateral, and LAD CTO were independent predictors of GW tracking failure in patients undergoing retrograde CTO PCI via poor septal CC.

The safety and feasibility of live-stream proctoring for CTO procedures.

OBJECTIVE: To assess the technical feasibility of a new method of educational training, based on audio-video (AV) communication between an interventional cardiologist and the cath lab staff members in one location and a remote expert proctor. METHODS: Overall, 9 patients underwent a percutaneous coronary intervention (PCI) targeting a chronic total occlusion (CTO) between June 2021 and January 2022 at a single Belgian center using the virtual proctoring approach. For this assessment, the strategic planning of the CTO PCI and all the decisions throughout the intervention were the responsibility of the proctor. The operator was guided via an AV link, by the proctor throughout the procedure. RESULTS: The operator performed each procedural step, guided by the remote proctor, who had continuous access to all relevant interventional details. No major adverse cardiac events (MACE) occurred during the index hospitalization or within 6 months follow-up. CONCLUSIONS: A new method of virtual proctoring based on live AV communication is feasible, even in the case of highly complex CTO PCI procedures. This strategy also appears safe and may provide the patient the benefit of incremental expertise. This approach is facilitated by advances in AV communication and allows physicians to share expertise irrespective of location. It could increase global interaction between colleagues and facilitate sharing of knowledge, which are both key aspects in the development of CTO PCI. This preliminary experience could serve as a basis for future large studies to study the potential role and benefits of virtual proctoring for complex CTO PCI procedures.

The Retrograde Approach to Chronic Total Occlusion Percutaneous Coronary Interventions: Technical Analysis and Procedural Outcomes.

BACKGROUND: Retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with lower success and higher complication rates when compared with the antegrade approach. OBJECTIVES: This study sought to assess contemporary techniques and outcomes of retrograde CTO PCI. METHODS: We examined the baseline characteristics, procedural techniques and outcomes of 4,058 retrograde CTO PCIs performed at 44 centers between 2012 and 2023. Major adverse cardiac events (MACE) included any of the following in-hospital events: death, myocardial infarction, repeat target vessel revascularization, pericardiocentesis, cardiac surgery, and stroke. RESULTS: The average J-CTO (Multicenter CTO Registry in Japan) score was 3.1 ± 1.1. Retrograde crossing was successful in 60.5% and lesion crossing in 81.6% of cases. The collaterals pathways successfully used were septals in 62.0%, saphenous vein grafts in 17.4%, and epicardials in 19.1%. The technical and procedural success rates were 78.7% and 76.6%, respectively. When retrograde crossing failed, technical success was achieved in 50.3% of cases using the antegrade approach. In-hospital MACE was 3.5%. The clinical coronary perforation rate was 5.8%. The incidence of in-hospital MACE with retrograde true lumen crossing, just marker antegrade crossing, conventional reverse controlled antegrade and retrograde tracking (CART), contemporary reverse CART, extended reverse CART, guide-extension reverse CART, and CART was 2.1%, 0.8%, 5.5%, 3.0%, 2.1%, 3.2%, and 4.1%, respectively; P = 0.01). CONCLUSIONS: Retrograde CTO PCI is utilized in highly complex cases and yields moderate success rates with 5.8% perforation and 3.5% periprocedural MACE rates. Among retrograde crossing strategies, retrograde true lumen puncture was the safest. There is need for improvement of the efficacy and safety of retrograde CTO PCI.

Safety and Efficiency of Rotational Atherectomy in Chronic Total Coronary Occlusion-One-Year Clinical Outcomes of an Observational Registry.

The study sought to assess the procedural success of rotational atherectomy (RA) in coronary chronic total occlusion (CTO) and to investigate the in-hospital and one-year outcomes following RA. From 2015 to 2019, patients undergoing percutaneous coronary intervention for CTO (CTO PCI) were retrospectively included into the hospital database. The primary endpoint was procedural success. Secondary endpoints were in-hospital and one-year major adverse cardiovascular and cerebral event (MACCE) rates. During the study period of 5 years, 2.789 patients underwent CTO PCI. Patients treated with RA (n = 193, 6.92%) had a significantly higher procedural success (93.26% vs. 85.10%, p = 0.0002) compared to those treated without RA (n = 2.596, 93.08%). Despite a significantly higher rate of pericardiocentesis (3.11% vs. 0.50%, p = 0.0013) in the RA group, the in-hospital and one-year MACCE rate was similar in both groups (4.15% vs. 2.77%, p = 0.2612; 18.65% vs. 16.72%, p = 0.485). In conclusion, RA is associated with higher procedural success for CTO PCI, but has higher risks for pericardial tamponade than CTO PCI without the need for RA. Nevertheless, in-hospital and one-year MACCE rates did not differ in-between both groups.

The value of quantitative plaque analysis based on coronary computed tomography angiography in predicting the percutaneous coronary intervention outcome of chronic total occlusion lesions.

Background: Due to the uncertainty of the success of percutaneous coronary intervention (PCI) and the complexity of selecting suitable treatment cases, the interventional outcome of coronary chronic total occlusion (CTO) remains challenging. The purpose of this study was to evaluate the role of quantitative plaque analysis based on coronary computed tomography angiography (CCTA) in predicting the CTO-PCI outcome. Methods: We retrospectively included 78 patients with CTO (80 lesions) confirmed by invasive coronary angiography from July 2016 to December 2018. All patients underwent PCI treatment according to standard practice. A total of 47 lesions in 47 patients were successfully treated with PCI. PCI failed in the remaining 33 lesions in 31 patients. The following conventional CCTA morphologic parameters were evaluated and compared between the PCI-success and PCI-failure groups: stump morphology; occlusion length, tortuous course; CTO lesion calcium; bridging collateral vessel; retrograde collateral vessel; the appearance of the occluded distal segment; and quantitative CTO plaque characteristics, including total plaque volume, calcified plaque (CP) volume, noncalcified plaque (NCP) volume, low-density noncalcified plaque (LDNCP) volume, and plaque length. Univariate and multivariate logistic regression analyses were performed to determine independent parameters predictive of CTO-PCI outcomes. The predictive performances were assessed using receiver operating characteristic curve analysis. Results: The blunt stump was the only independent CCTA morphologic parameter to predict the outcome of CTO-PCI [odds ratio (OR): 10.807; P<0.001]. NCP volume (OR: 1.018; P<0.001), CP volume (OR: 1.026; P=0.049), and plaque length (OR: 1.058; P=0.037) were independent quantitative CTO plaque characteristics predictive of CTO-PCI outcomes. The plaque-based model combining NCP volume with CP volume and plaque length had a higher area under the curve (AUC =0.96) than did the morphology-based model that included blunt stump (AUC 0.68) in predicting the outcomes of CTO-PCI (P<0.001). Conclusions: The CCTA-based plaque characteristics, including NCP volume, CP volume, and plaque length, outperformed morphologic parameters in predicting the CTO-PCI outcomes.

Computed Tomography Angiography-Derived Scores for Prediction of Chronic Total Occlusion Percutaneous Coronary Intervention Using the Hybrid Algorithm.

Whereas coronary computed tomography angiography (CCTA) exceeds invasive angiography for predicting the procedural outcome of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), CCTA-derived scores have never been validated in the hybrid CTO PCI population. In this single-center, retrospective, observational study, we included 108 consecutive patients with 110 CTO lesions and preprocedural CCTA who underwent hybrid CTO PCI to assess the diagnostic accuracy of CCTA-derived scoring systems. Successful guidewire crossing within 30 min was set as the primary endpoint. The secondary endpoints were final procedural success and the need for using any non-antegrade wiring (AW) strategy within the hybrid algorithm. Time-efficient guidewire crossing and final procedural success were achieved in 53.6% and 89.1% of lesions, respectively, while in 36.4% of the procedures, any non-AW strategy was applied. The median J-CTO score was 1 (interquartile range (IQR): 0, 2), while the CT-RECTOR, KCCT, J-CTOCCTA, and RECHARGECCTA scores were 2 (IQR: 1, 3), 3 (IQR: 2, 5), 1 (IQR: 0, 3), and 2 (IQR: 1, 3), respectively. All scores were significantly higher in the lesions with failed versus successful time-efficient guidewire crossing. Although all of the CCTA-derived scores had numerically higher predictive values than the angiographic J-CTO score, no significant differences were noted between the scores in any of the analyzed study endpoints. High sensitivity of the CT-RECTOR and RECHARGECCTA scores (both 89.8%) for predicting successful guidewire crossing within 30 min, and high sensitivity (90.8%) of the KCCT score for predicting final procedural success, were noted. CCTA-derived scoring systems are accurate, noninvasive tools for the prediction of the procedural outcome of hybrid CTO PCI, and may aid in identifying the need for use of the hybrid algorithm.