Coronary Chronic Total Occlusion Revascularization Research Articles

Coronary Chronic Total Occlusion Revascularization: When, Who and How?

Coronary chronic total occlusions (CTO) are an increasingly frequent entity in clinical practice and represent a challenging percutaneous coronary intervention (PCI) scenario. Despite data from randomized trials that have not yet demonstrated a clear benefit of CTO recanalization, the widespread of CTO-PCI has substantially increased. The improvement in operators' techniques, equipment, and training programs has led to an improvement in the success rate and safety of these procedures, which will represent an important field of future development of PCI. The present review will summarize clinical outcomes and technical and safety issues of CTO revascularization with the aim to guide clinical daily cath-lab practice.

Outcomes following coronary chronic total occlusion revascularization with drug-coated balloons.

Despite the introduction of improved drug eluting stents (DES), the rate of repeat revascularization procedures following percutaneous coronary interventions (PCI) in coronary chronic total occlusions (CTO) remains high. By leaving vessels uncaged and limiting length of stented segments, drug-coated balloons (DCB) represent an appealing alternative to DES for CTO-PCI. Since data supporting the use of DCBs in CTO-PCI is scarce, we compared the outcomes of patients undergoing CTO-PCI involving DCBs vs DES only. From 2 prospective registries, outcomes of patients undergoing CTO-PCI involving DCBs and those undergoing PCI with DES only were compared. Outcomes included major adverse cardiac and cerebrovascular events (MACCE) and cardiovascular death (CV-death). Overall, 157 patients were studied; 112 (71%) underwent CTO-PCI involving DCBs and 45 (29%) were treated with DES only. Mean J-CTO score was 1.84 ± 0.7. Most CTO-lesions involved the right coronary artery, 88 (56%), and 26 (17%) cases were in-stent occlusions. In the DCB group, 46 (41%) lesions were treated with DCBs alone. Mean lengths of the stented segments in the DCB vs DES cohorts were 59 ± 28 mm vs 87 ± 37 mm (P less than .001), respectively. After 12 months, the MACCE rate was higher in the DES only vs DCB group (26% vs 11%, P=.03). Length of the stented segment was an independent predictor for MACCE (HR 1.15 [95% CI, 1.05-1.26] per 10-mm stent length). Revascularization of CTO lesions involving DCBs appears safe and potentially lowers MACCE rates compared to treatment with DES alone. Importantly, using DCBs for CTO treatment may reduce total stent length, which determines PCI outcomes.

Outcomes following coronary chronic total occlusion revascularization with drug-coated balloons.

Despite the introduction of improved drug eluting stents (DES), the rate of repeat revascularization procedures following percutaneous coronary interventions (PCI) in coronary chronic total occlusions (CTO) remains high. By leaving vessels uncaged and limiting length of stented segments, drug-coated balloons (DCB) represent an appealing alternative to DES for CTO-PCI. Since data supporting the use of DCBs in CTO-PCI is scarce, we compared the outcomes of patients undergoing CTO-PCI involving DCBs vs DES only. From 2 prospective registries, outcomes of patients undergoing CTO-PCI involving DCBs and those undergoing PCI with DES only were compared. Outcomes included major adverse cardiac and cerebrovascular events (MACCE) and cardiovascular death (CV-death). Overall, 157 patients were studied; 112 (71%) underwent CTO-PCI involving DCBs and 45 (29%) were treated with DES only. Mean J-CTO score was 1.84 ± 0.7. Most CTO-lesions involved the right coronary artery, 88 (56%), and 26 (17%) cases were in-stent occlusions. In the DCB group, 46 (41%) lesions were treated with DCBs alone. Mean lengths of the stented segments in the DCB vs DES cohorts were 59 ± 28 mm vs 87 ± 37 mm (P less than .001), respectively. After 12 months, the MACCE rate was higher in the DES only vs DCB group (26% vs 11%, P=.03). Length of the stented segment was an independent predictor for MACCE (HR 1.15 [95% CI, 1.05-1.26] per 10-mm stent length). Revascularization of CTO lesions involving DCBs appears safe and potentially lowers MACCE rates compared to treatment with DES alone. Importantly, using DCBs for CTO treatment may reduce total stent length, which determines PCI outcomes.

Circ-MBOAT2 Regulates Angiogenesis via the miR-495/NOTCH1 Axis and Associates with Myocardial Perfusion in Patients with Coronary Chronic Total Occlusion.

Revascularization of coronary chronic total occlusion (CTO) still remains controversial. The factors that impact collateral circulation and myocardial perfusion are of interest. Circular RNA (circRNA) has been shown to regulate the process of angiogenesis. However, the effects of circ-membrane-bound O-acyltransferase domain containing 2 (circ-MBOAT2) on angiogenesis in patients with CTO were unclear. In this study, we evaluated circulating circRNAs and miRNAs in patients with CTO and stable coronary artery disease using high-throughput sequencing. Another cohort of patients were selected to verify the expressions of circ-MBOAT2 and miR-495. The role and mechanism of circ-MBOAT2 in the process of angiogenesis were explored through in vitro and vivo studies. Finally, we came back to a clinical perspective and investigated whether circ-MBOAT2 and miR-495 were associated with the improvement of myocardial perfusion evaluated by single-photon emission computed tomography (SPECT). We found that the expression of circ-MBOAT2 was significantly up-regulated while miR-495 was significantly down-regulated in patients with CTO. The expression of circ-MBOAT2 was negatively correlated with miR-495 in patients with CTO. In an in vitro study, we found that circ-MBOAT2 promoted tube formation and cell migration via the miR-495/NOTCH1 axis in endothelial cells. In an in vivo study, we showed that the inhibition of miR-495 caused the increase in collateral formation in mice after hindlimb ischemia. In a human study, we showed the expressions of circ-MBOAT2 and miR-495 were associated with myocardial perfusion improvement after revascularization of CTO. In conclusion, circ-MBOAT2 regulates angiogenesis via the miR-495/NOTCH1 axis and associates with myocardial perfusion in patients with CTO. Our findings suggest that circ-MBOAT2 and miR-495 may be potential therapeutic targets and prognostic factors for patients with CTO.

Clinical outcomes of percutaneous coronary intervention in chronic total occlusion in patients with type 2 diabetes mellitus

Introduction and ObjectivesCoronary chronic total occlusions (CTOs) are relatively common findings in patients with type 2 diabetes mellitus (T2DM). However, the indication for percutaneous coronary intervention (PCI) and its clinical benefit in these patients remain controversial. MethodsA single-center retrospective cohort study with prospectively collected outcomes was carried out with CTO patients undergoing PCI in 2019 and 2020. Patients were divided into two groups according to previous T2DM diagnosis (T2DM and non-T2DM). The primary outcome was recurrence of angina and/or heart failure symptoms and secondary outcomes were myocardial infarction and all-cause mortality. ResultsA total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome (total symptom recurrence) occurred in 16.6% of the sample, with no difference between groups (non-T2DM 13.6% vs. T2DM 21.2%, p=0.194) in a two-year follow-up. Angina recurrence was significantly more frequent in T2DM patients (15.2%, p=0.043). The presence of T2DM was not an independent predictor of symptom recurrence (p=0.429, HR 1.37, 95% CI 0.62–2.98). Myocardial infarction and all-cause mortality were also not different between groups (T2DM 1.5%, p=0.786 and 4.5%, p=0.352, respectively, on survival analysis). Independent predictors of all-cause mortality were left ventricular function and creatine clearance (p=0.039, HR 0.92, 95% CI 0.85–0.99 and p=0.013, HR 0.96, 95% CI 0.93–0.99, respectively). ConclusionsT2DM did not influence outcomes in CTO patients undergoing PCI, and its presence should not be a limiting factor in deciding on CTO revascularization.

Incidence of ventricular arrhythmias in patients with chronic total coronary occlusion: Results of the VACTOR study

BackgroundA chronic total coronary occlusion (CTO) is associated with ventricular arrhythmias (VA) in patients with an implantable cardioverter-defibrillator (ICD). Limited data is available on the incidence of VA in CTO patients without an ICD. ObjectivesTo investigate the incidence of sustained VA in CTO patients after successful CTO revascularization and in patients with untreated CTO or failed CTO revascularization. MethodsProspective, multicenter observational pilot study including CTO patients who were not eligible for an ICD and had a left ventricular ejection fraction >35 %. We enrolled patients with a successful CTO revascularization (group A) and patients with untreated CTO or failed CTO revascularization (group B). All patients received an implantable loop recorder with remote monitoring. The primary endpoint was sustained VA. ResultsNinety patients were enrolled (mean age 63 ± 10 years, 83.3 % man, mean LVEF 55 ± 8 %). Group A (n = 45) had a higher prevalence of CTO in the left anterior descending artery in comparison to group B (n = 45) (28.9 % versus 4.4 %, P = 0.002). Other baseline characteristics were similar. During a median follow-up time of 26 months (IQR, 19–35), five patients (5.6 %) had a sustained VA. There was no difference in the incidence of sustained VA between groups (3-year cumulative event rate: 8.8 % (group A) versus 4.5 % (Group B), log-rank P = 0.71). ConclusionPatients with an CTO, who do not qualify for an ICD, have a substantial risk of sustained VA. In our study the incidence was not different between patients with revascularized and those with untreated CTO.

Abstract 12820: Utilization of Cardiac Magnetic Resonance Imaging for Management of Coronary Chronic Total Occlusions

Introduction: Revascularization of coronary chronic total occlusions (CTOs) may be indicated for relief of medically refractory angina. Myocardial viability assessment by cardiac magnetic resonance (CMR) may help select patients for CTO intervention. Real-world practice is not well described. Methods: We identified patients who underwent coronary angiography between 2016-2020 at a large tertiary center and had ≥1 CTO. Patients with prior CABG were excluded. We examined rates of CMR and outcomes including revascularization and MACE. Myocardial segments were attributed to a CTO territory and adjudicated following angiographic review of coronary anatomy. Significant CMR viability was defined as <50% transmural delayed enhancement in the CTO territory. Results: We identified 1279 patients (74.1% male, 28.1% Black) who met inclusion criteria. Of these, 36.0% had type 2 diabetes mellitus and 54.9% reported angina pectoris. Over half of patients had CTO of the RCA (56.5%), and 18.5% of patients had CTO in >1 vessel. Non-invasive testing was performed in 38.4% of patients; 10.8% had CMR. Rates of CMR were higher in patients with severely reduced EF (≤35%) compared to those with normal EF (≥55%) (22.1% vs 11.1%; p<0.001). Among those who had CMR, 84.8% of patients showed significant viability in the CTO territory (Fig). CTO PCI was performed in 12.5% of patients, CABG was performed in 24.9%, and 63.2% were managed medically. Patients who had CTO PCI had higher rates of angina versus those without CTO PCI (70.0% vs 52.8%; p<0.001) and were more likely to be on ≥2 anti-anginal medications (30.6% vs 18.9%; p<0.001). CTO PCI technical success was achieved in 69.5% of patients and MACE occurred in 2.3% of cases. Conclusions: Patients with coronary CTOs demonstrate high rates of viability in CTO territories based on CMR. Rates of viability testing and CTO revascularization remain low. Further work is needed to determine the role of CMR and other non-invasive testing in CTO management.

Impact of Coronary Chronic Total Occlusion on Long-term Clinical Outcome in Patients with Unprotected Left Main Disease Undergoing Percutaneous Coronary Intervention

Objectives: Reported data regarding the prevalence, prognostic impact, and safety and efficacy of revascularization of coronary chronic total occlusion (CTO) in patients with left main coronary artery (LMCA) disease who undergo percutaneous coronary intervention (PCI) are scarce. The aim of the present study was to compare clinical outcomes among patients with LMCA disease undergoing PCI. Outcomes were compared between those with and without coronary CTO and between those with CTO who had successful and unsuccessful CTO recanalization procedures. Methods: All consecutive patients with significant LMCA disease (>50% stenosis at coronary angiography) who underwent PCI between July 2014 and December 2018 were retrospectively included in our study. The primary endpoint of the study was long-term mortality. Secondary endpoints included the incidence of myocardial infarction, repeat percutaneous or surgical revascularization, stroke, and stent thrombosis. Results: Between July 2014 and December 2018, 578 patients underwent PCI for LMCA disease at Pederzoli Hospital and University of Turin were enrolled. They were divided into 3 groups: group A: 374 (65%) patients without CTO, group B: 108 (19%) patients with untreated or unsuccessfully treated CTO, and group C: 96 (17%) patients with successfully treated CTO. At a median follow-up of (1090 ± 279) days, there were no statistically significant differences between the groups in terms of the primary and secondary endpoints. However, there was a trend towards higher mortality in patients with untreated or unsuccessfully treated CTO (13% vs. 19% vs. 14% in groups A, B, and C, respectively; P = 0.12). The primary and secondary endpoints were further analyzed based on the presence or absence of myocardial viability: subgroup C1: 54 (56%) patients with successful percutaneous transluminal coronary angioplasty (PTCA) having viability, and subgroup C2: 42 (44%) patients with successful PTCA not having viability. There was a trend toward a statistically significant higher rate of death among patients in group B, who underwent unsuccessful recanalization with viable myocardium (19% vs. 9% vs. 19% in groups B, C1, and C2, respectively, P = 0.05). On multivariable analysis, the propensity for successful revascularization of CTO was associated with a reduced risk of death (P = 0.01; odds ratio, 0.75; 95% confidence interval: 0.62–0.87). Conclusions: Among patients with LMCA disease undergoing PCI, CTO represents a common finding associated with worse prognosis. Successful revascularization of CTO in patients with viable myocardium appears to significantly improve prognosis.

Revascularization of chronic total occlusion coronary artery and cardiac regeneration.

Coronary chronic total occlusion (CTO) contributes to the progression of heart failure in patients with ischemic cardiomyopathy. Randomized controlled trials demonstrated that percutaneous coronary intervention (PCI) for CTO significantly improves angina symptoms and quality of life but fails to reduce clinical events compared with optimal medical therapy. Even so, intervening physicians strongly support CTO-PCI. Cardiac regeneration therapy after CTO-PCI should be a promising approach to improving the prognosis of ischemic cardiomyopathy. However, the relationship between CTO revascularization and cardiac regeneration has rarely been studied, and experimental studies on cardiac regeneration usually employ rodent models with permanent ligation of the coronary artery rather than reopening of the occlusive artery. Limited early-stage clinical trials demonstrated that cell therapy for cardiac regeneration in ischemic cardiomyopathy reduces scar size, reverses cardiac remodeling, and promotes angiogenesis. This review focuses on the status quo of CTO-PCI in ischemic cardiomyopathy and the clinical prospect of cardiac regeneration in this setting.

The Impact of Successful Percutaneous Coronary Intervention on the Reduction of Major Cardiovascular Events in Patients with Chronic Total Coronary Occlusion In dr. Saiful Anwar's Malang Hospital

Background: Chronic total coronary occlusion (CTOs) is associated with an increased risk of adverse clinical outcomes. The benefits of percutaneous coronary intervention (PCI) in CTO are still being debated due to the limited data available. This study aims to determine the relationship between the success of PCI in CTOs and the reduction of major cardiovascular events compared to those who failed or did not perform revascularization in patients with chronic coronary total occlusion in RSUD by Dr. Saiful Anwar Malang. Methods:This study is an analytic observational study with a retrospective cohort design. Of a total of 2165 patients who underwent angiography at Saiful Anwar Hospital, Malang, for the period August 2017–September 2020, consecutively, 578 patients with lesions of at least one CTO were found. There were 68 patients who were excluded, so 510 patients were analyzed in this study. They were divided into two groups, the CTO group that was successfully revascularized with PCI (n = 141) and the group that was not revascularized (n = 369). The outcome of this study was major cardiovascular events (MACE), which included cardiac mortality , all cause mortality, and rehospitalization events. Result: Patients with CTO who were not revascularized compared to those with revascularized CTO had a higher history of heart failure, involvement of LM disease, multivessel disease, and three vessel disease (41.2% vs 18.4%, p = 0.041; 16.5% vs 1.8%, p < 0.001; 69.4% vs 22.7%, p < 0.001; 56.5% vs 14.1%, p < 0.001) with a lower mean LVEF (0.49 ± 0.06 vs 0.51 ± 0.07, p=0.045) and older age (60±9 vs 57±8 years ; p=0.007).. At a 12-month follow-up, in the CTO group that was successfully revascularized by PCI, there was a better prognosis than the non-revascularized CTO group in terms of major cardiovascular events (19.9% vs 33.1% Plog-rank = 0.002). These results were consistent for all-cause mortality (5.5% vs 20.6%, Plog-rank =0.027), cardiac mortality (3.7% vs 20.6%, Plog-rank < 0.001) and rehospitalization events. (7.5% vs 32.2%, Plog-rank = 0.001). Conclusion: Successful revascularization of CTO by PCI may provide clinical benefits in patients with CTO in association with major cardiovascular events.

PO-716-03 THE EFFECT OF CORONARY CHRONIC TOTAL OCCLUSION REVASCULARIZATION ON ATRIAL AND VENTRICULAR ARRHYTHMIAS

Revascularization of coronary Chronic Total Occlusion (CTO) improves anginal symptoms and left ventricular performance. Furthermore, infarct related CTO of coronary arteries are associated with ventricular arrhythmias. However, the impact of CTO revascularization on ventricular arrhythmias and atrial fibrillation is unclear.

Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With Prior Coronary Artery Bypass Graft: Current Evidence and Future Perspectives.

Coronary chronic total occlusion (CTO), which occurs in 18. 4–52% of all patients referred for coronary angiography, represents one of the last barriers in coronary intervention. Approximately half of all patients with prior coronary artery bypass graft (CABG), who undergo coronary angiography, are diagnosed with coronary CTO. In fact, these patients often develop recurrent symptoms and events, necessitating revascularization. Currently, there is neither a consensus nor developed guidelines for the treatment of CTO patients with prior CABG, and the prognosis of these patients remains unknown. In this review, we discuss current evidence and future perspectives on CTO revascularization in patients with prior CABG, with special emphasis on clinical and lesion characteristics, procedural success rates, periprocedural complications, and long-term outcomes.

The last resort during complex retrograde percutaneous coronary chronic total occlusion intervention: Extraplaque intracoronary lithotripsy to externally crush a heavy calcified occluded stent

Chronic total occlusions (CTO) due to in-stent restenosis represent a challenging lesion subset for percutaneous coronary intervention in particular when associated with coronary calcification. Sometimes CTO lesions require antegrade or retrograde dissection-re-entry techniques with extraplaque dilation. Recently intravascular lithotripsy (IVL) emerged as a therapeutic option for the treatment of severely calcified coronary lesions but its role in extraplaque dilation is not described. In this report, we present a case of retrograde complex percutaneous coronary chronic total occlusion revascularization accomplished by the use of extraplaque IVL necessary to externally crush a heavy calcified previous implanted stent.

TCT-414 Safety and Efficacy of Dedicated Guidewire, Microcatheter, and Guide Catheter Extension Technologies for Chronic Total Coronary Occlusion Revascularization: Primary Results of the Teleflex Chronic Total Occlusion Study

TCT-414 Safety and Efficacy of Dedicated Guidewire, Microcatheter, and Guide Catheter Extension Technologies for Chronic Total Coronary Occlusion Revascularization: Primary Results of the Teleflex Chronic Total Occlusion Study

National prevalence and outcomes of coronary chronic total occlusion revascularization in patients with congestive heart failure

Abstract Background There is limited data on the prevalence and outcomes of coronary artery chronic total occlusion (CTO) revascularization in patients with congestive heart failure. Purpose Our goal is to study the prevalence and outcomes of CTO revascularization in terms of in-hospital mortality, re-admission rate, and complications in patients stratified by their heart failure status. Methods Patients with CTO who underwent percutaneous coronary intervention (PCI) were included for the years 2010 - 2018 from the national readmission database. We compared the national trends, prevalence and outcomes of CTO revascularization in patients with no heart failure, heart failure with preserved ejection fraction (HFpEF), and heart failure with reduced ejection fraction (HFrEF) using one-way ANOVA and logistic regression. Results A total of 166,244 (69±11 years, 26% women) patients with coronary CTO who underwent PCI were identified. Of these, 131,664 (79%) patients had no clinical diagnosis of HF, while 26,612 (16%) patients had HFpEF, and 7,968 (5%) patients had HFrEF. Majority of patients with HFpEF and HFrEF had a moderate to high Elixhauser comorbidity score, while those with no HF had mostly low to moderate score (p<0.001). We observed a steady decrease in annual CTO revascularization from a total of 24,708 in 2010 to 13,505 in 2018. However, the percentage of CTO revascularization in patients with HFrEF has increased during this period from 2% in 2010 to 8% in 2018. Interestingly, patients with HFpEF had higher rates of cardiac arrest (Odds Ratio (OR) 2.2; 95% Confidence Interval (CI) 1.8–2.7, p<0.001), ventricular tachycardia/fibrillation (OR 3.7; 95% CI 3.4–4.0, p<0.001), use of mechanical support (OR 5.5; 95% CI 4.9–6.2, p<0.001), and death during admission (OR 2.2; 95% CI 1.8–2.7, p<0.001) than those with no HF and with HFrEF. Similarly, patients with HFpEF had higher rates of intensive care unit admission (9%), than those with HFrEF (5%), and no HF (2%) (p<0.001). Readmission rates were similar across all three groups (0.5–0.7%, p=0.06). The median cost of hospitalization was significantly higher in the HFpEF group compared to the other groups ($98,366, p<0.001). Conclusion In this cohort of patients, we observed an overall annual decline in CTO revascularization over the 8-year study period. Despite this decline, we observed an increase in CTO revascularization in patient with HFrEF. Interestingly, patients with HFpEF had elevated in hospital mortality and higher rates of cardiac arrest, ventricular arrhythmias, mechanical circulatory support, and admission to the cardiac care unit than those with no HF, or those with HFrEF. Despite their persevered ejection fraction, our findings suggest that CTO revascularization in with patients with HFpEF carry a significant risk, thus risks versus benefits in this group of patients should be weighed considerably before attempting revascularization. Funding Acknowledgement Type of funding sources: None.

The effect of chronic total coronary occlusion percutaneous coronary intervention on absolute perfusion in remote myocardium

Abstract Background Successful revascularization of a chronic total coronary occlusion (CTO) impacts coronary physiology of the remote myocardial territory. Purpose This study evaluated the effect of CTO percutaneous coronary intervention (PCI) on changes in absolute perfusion in remote myocardium as assessed by serial [15O]H2O positron emission tomography (PET) perfusion imaging. Methods A total of 164 patients underwent [15O]H2O PET imaging at baseline and 3 months after successful single-vessel revascularization of a CTO to evaluate changes in hyperemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) in the remote myocardial territory supplied by both non-target coronary arteries. Results Remote hMBF and CFR improved (2.29±0.67 to 2.48±0.75 mL min–1 g–1 and 2.48±0.76 to 2.74±0.85, respectively) after CTO revascularization (p<0.01 for both). Absolute perfusion indices in the CTO vessel and the remote myocardium showed a positive linear correlation, both before (r=0.75, p<0.01 and r=0.77, p<0.01 for hMBF and CFR, respectively) and after (hMBF: r=0.87, p<0.01 and CFR: r=0.81, p<0.01) CTO PCI. Absolute increases in remote myocardial perfusion were largest in patients with a higher increase in hMBF (βeta [β] 0.56; 95% CI: 0.47–0.65; p<0.01) and CFR (β 0.51 (0.42–0.60); p<0.01) in the CTO territory, independent of clinical, angiographic and procedural characteristics. Furthermore, baseline (hMBF: β −0.24 (−0.39, −0.08); p<0.01 and CFR: β −0.26 (−0.41, −0.11); p<0.01) and post-PCI perfusion (hMBF: β 0.36; (0.27, 0.46); p<0.01 and CFR: β 0.30 (0.21, 0.40); p<0.01) in the CTO vessel were independently associated with the increase in remote myocardial perfusion after CTO PCI. Conclusions An overall increase in remote myocardial perfusion was observed following CTO PCI. Absolute perfusion indices in the remote myocardium showed a positive linear correlation with perfusion in the CTO vessel, before and after CTO revascularization. Importantly, baseline, post-PCI and the absolute increase in perfusion in the CTO territory were independently associated with increases in remote myocardial perfusion after revascularization. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Integrative analysis of hybrid PET/MR improves recovery prediction of left ventricular contractility after percutaneous revascularisation of coronary chronic total occlusions

Abstract Background The clinical indication to revascularization of coronary chronic total occlusions (CTO) is set on viability assessment through well-established imaging methods. Precise characterization of the myocardium allows a better interventional risk stratification before revascularization. Hybrid positron emission tomography/magnetic resonance (PET/MR) scanners allow the combination of image based biomarkers through simultaneous acquisition and may potentially improve the prediction of therapy response. This study aims to evaluate the accuracy in recovery prediction after CTO revascularization by combining information of myocardial viability and wall motion abnormalities (WMA) from PET/MR exams. Methods Viability was assessed with PET/MR imaging in 22 patients before percutaneous revascularization of a CTO. A cardiac MR imaging was performed at follow-up after 6 months. Segmental WMA was assessed on the AHA 17-segments model from cine images at baseline and follow-up with a 5-point scale. Recovery of WMA was predicted using six different models combining parameters from fluorodeoxyglucose (FDG) uptake, transmural extent of the scar with late gadolinium enhancement image (LGE), T1 mapping, and WMA at baseline. From 374 myocardial segments, we considered only 82 that were completely characterized and presented at least hypokinetic WMA at baseline. 46 of them were supplied by the treated CTO artery (CTO-subtended), wherefrom 16 segments recovered the contractility. A Random Forest classifier was applied for recovery prediction. Training and testing data were selected through stratified random sampling (50 iterations) with replacement from the two sets: CTO-subtended and non-CTO-subtended segments. To compensate for class imbalance and limited sample size, SMOTE oversampling was applied to the training data. Prediction assessment was based on balanced accuracy (bAcc), sensitivity, specificity, ROC AUC, and Precision-Recall AUC (PR AUC), while Wilcoxon test with a Bonferroni's correction was used for comparison between the proposed models and LGE+FDG, which has shown the best performance in previous studies [1,2]. Results The best model for the prediction of recovery after revascularisation was the combination of LGE+FDG+WMA+T1mapping (bAcc 0.62±0.11, sensitivity 0.72±0.18, specificity 0.70±0.19, ROC AUC 0.67±0.12, PR AUC 0.60±0.12), followed by LGE+FDG+WMA, LGE+FDG+T1mapping, LGE+FDG, LGE, and FDG, respectively. The first model statistically significantly (p-value<0.01) outperformed the reference model LGE+FDG (bAcc 0.54±0.11, sensitivity: 0.67±0.18, specificity 0.55±0.19, ROC AUC 0.56±0.13, PR AUC 0.47±0.10). Conclusion This study documents the benefits of a hybrid PET/MR multiparametric assessment beyond the standard analysis based on FDG uptake and LGE for the prediction of contractility recovery after revascularization of CTO of the coronary arteries. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 764458 PETMR protocolROC AUC comparsion

Safety and efficacy of dedicated guidewire, microcatheter, and guide catheter extension technologies for chronic total coronary occlusion revascularization: Primary results of the Teleflex Chronic Total Occlusion Study.

Description of procedural outcomes using contemporary techniques that apply specialized coronary guidewires, microcatheters, and guide catheter extensions designed for chronic total occlusion (CTO) percutaneous revascularization is limited. A prospective, multicenter, single-arm study was conducted to evaluate procedural and in-hospital outcomes among 150 patients undergoing attempted CTO revascularization utilizing specialized guidewires, microcatheters and guide extensions. The primary endpoint was defined as successful guidewire recanalization and absence of in-hospital cardiac death, myocardial infarction (MI), or repeat target lesion revascularization (major adverse cardiac events, MACE). The prevalence of diabetes was 32.7%; prior MI, 48.0%; and previous bypass surgery, 32.7%. Average (mean ± standard deviation) CTO length was 46.9 ± 20.5 mm, and mean J-CTO score was 1.9 ± 0.9. Combined radial and femoral arterial access was performed in 50.0% of cases. Device utilization included: support microcatheter, 100%; guide catheter extension, 64.0%; and mean number of study guidewires/procedure was 4.8 ± 2.6. Overall, procedural success was achieved in 75.3% of patients. The rate of successful guidewire recanalization was 94.7%, and in-hospital MACE was 19.3%. Achievement of TIMI grade 2 or 3 flow was observed in 93.3% of patients. Crossing strategies included antegrade (54.0%), retrograde (1.3%) and combined antegrade/retrograde techniques (44.7%). Clinically significant perforation resulting in hemodynamic instability and/or requiring intervention occurred in 16 (10.7%) patients. In a multicenter, prospective registration study, favorable procedural success was achieved despite high lesion complexity using antegrade and retrograde guidewire maneuvers and with acceptable safety, yet with comparably higher risk than conventional non-CTO PCI.

Functional recovery after percutaneous revascularization of coronary chronic total occlusions: insights from cardiac magnetic resonance tissue tracking

To evaluate the effect of percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) on left ventricular (LV) strain assessed using cardiac magnetic resonance (CMR) tissue tracking. In 150 patients with a CTO, longitudinal (LS), radial (RS) and circumferential shortening (CS) were determined using CMR tissue tracking before and 3 months after successful PCI. In patients with impaired LV strain at baseline, global LS (10.9 ± 2.4% vs 11.6 ± 2.8%; P = 0.006), CS (11.3 ± 2.9% vs 12.0 ± 3.5%; P = 0.002) and RS (15.8 ± 4.9% vs 17.4 ± 6.6%; P = 0.001) improved after revascularization of the CTO, albeit to a small, clinically irrelevant, extent. Strain improvement was inversely related to the extent of scar, even after correcting for baseline strain (B = − 0.05; P = 0.008 for GLS, B = − 0.06; P = 0.016 for GCS, B = − 0.13; P = 0.017 for GRS). In the vascular territory of the CTO, dysfunctional segments showed minor improvement in both CS (10.8 [6.9 to 13.3] % vs 11.9 [8.1 to 15.0] %; P < 0.001) and RS (14.2 [8.4 to 18.7] % vs 16.0 [9.9 to 21.8] %; P < 0.001) after PCI. Percutaneous revascularization of CTOs does not lead to a clinically relevant improvement of LV function, even in the subgroup of patients and segments most likely to benefit from revascularization (i.e. LV dysfunction at baseline and no or limited myocardial scar).

Original Article--Value of Pathological Q Waves and Angiographic Collateral Grade in Patients Undergoing Coronary Chronic Total Occlusion Recanalization: Cardiac Magnetic Resonance Study.

Background/aimSuccessful coronary chronic total occlusion (CTO) revascularization was found by many studies to be associated with improved left ventricular (LV) systolic function and survival if evidence of viability is present. Little is known about the association of CTO revascularization in patients with electrocardiographic Q waves and improvement in angina burden as a measurement of health-related quality of life (HRQOL) afterwards.MethodsIn this study, 100 patients with single vessel CTO were included. Myocardial viability was tested by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) and 50 patients showed evidence of viability. Seattle Angina Questionnaire (SAQ) scores were used as a measure of HRQOL.ResultsPathological Q waves were present in 48 patients (including 19 patients with viable CTO territory) out of 100 patients. Patients with Q waves tended to have worse Seattle Angina Questionnaire (SAQ) scores compared to those with no Q waves (31.2 ± 11.7 vs 45.3 ± 13.9 respectively, p = 0.002), worse LV systolic function and wall motion score index (WMSI) on CMR. They also had significantly less prevalence of viability (p < 0.001). Patients with Q waves and positive viability had lower SAQ scores (37.2 ± 10.1 vs 52.7 ± 13.2 respectively, p = 0.02), higher LVEF and lower WMSI. They also had well developed collateral grade (2.1 ± 1.03 vs 0.7 ± 0.82 respectively, p < 0.001). After successful percutaneous coronary intervention (PCI), in the viable LV group, presence of Q waves was not associated with better LV functional recovery, while those with higher collateral grades were more likely to have better LV functional recovery post CTO-PCI. Patients with Q waves and viable CTO territory showed significantly better SAQ scores compared to pre-PCI (87.3 ± 12.2 vs 37.2 ± 10.1 respectively, p < 0.001). For angina frequency, post–PCI score was 80.2 ± 7.9 compared to 39.2 ± 7.1 before PCI, p < 0.001). Multivariate regression analysis showed that pathological Q waves, Rentrop's collateral grade and the Canadian Cardiovascular Society (CCS) angina class before PCI were the most significant independent predictors of improved HRQOL as reflected by SAQ (OR for Q waves 7.83, 95% CI 1.62–18.91,p 0.003), (OR for Rentrop's collateral grade 8.31,95% CI 2.21–26.33, p < 0.001), (OR for CCS class 8.39, 95% CI 1.21–20.8, p 0.01).ConclusionWell-developed collateral circulation could independently predict LV functional recovery after CTO-PCI. Patients with Q waves and viable CTO territory tend to have higher CCS class before revascularization and get significant improvement of HRQOL after PCI. Other predictors of improved HRQOL are Rentrop's collateral grade and worse CCS class before PCI.