Is it Worthy Enough to Revascularize Chronically Occluded Coronaries?

Chronic total occlusions (CTOs) represent the "final frontier" of coronary interventions with the lowest procedural success rates and the most common reason for incomplete revascularization and referral to coronary artery bypass graft surgery (CABG). CTO lesions are not an infrequent finding during coronary angiography. They are often responsible for enhancing the complexity of the coronary disease burden thereby affecting the final interventional decision in the process. Notwithstanding the modest technical success of CTO-PCI, most of the earlier observational data demonstrated a clear survival benefit free of major cardiovascular events (MACE) in patients undergoing successful CTO revascularization. However, data from recent randomized trials fail to uphold the same survival advantage albeit, showing some trend toward improvement in left ventricular function, quality of life indicators and freedom from fatal ventricular arrythmia. Various guidance statements propose a well-defined role for CTO intervention in specific situations provided criterions for patient selection, appreciable inducible ischemia, myocardial viability and cost-risk-benefit analysis are met.

Impact of sex on myocardial perfusion following percutaneous coronary intervention of chronic total coronary occlusions

OBJECTIVES

We sought to investigate the impact of sex on myocardial perfusion changes following chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) as measured by [15O]H2O positron-emission tomography (PET) perfusion imaging.

BACKGROUND

CTO PCI has been associated with an increase in myocardial perfusion, yet females are less likely to undergo revascularization. As such, data on the impact of sex on myocardial perfusion following CTO PCI is scarce.

METHODS

A total of 212 patients were prospectively enrolled and underwent CTO PCI combined with [15O]H2O PET perfusion imaging prior to and 3 months after PCI. Hyperemic myocardial blood flow (hMBF, mL·min-1·g-1) and coronary flow reserve (CFR) allocated to the CTO territory were quantitatively assessed.

RESULTS

This study comprised 34 (16 %) females and 178 (84 %) males. HMBF at baseline did not differ between sexes. Females showed a higher increase in hMBF than males (Δ1.34 ± 0.67 vs. Δ1.06 ± 0.74, p = 0.044), whereas post-PCI hMBF was comparable (2.59 ± 0.85 in females vs. 2.28 ± 0.84 in males, p = 0.052). Female sex was independently associated with a higher increase in hMBF after correction for clinical covariates. CFR increase after revascularization was similar in females and males (Δ1.47 ± 0.99 vs. Δ1.30 ± 1.14, p = 0.711).

CONCLUSIONS

The present study demonstrates a greater recovery of stress perfusion in females compared to males as measured by serial [15O]H2O PET imaging. In addition, a comparable increase in CFR was found in females and males. These results emphasize the benefit of performing CTO PCI in both sexes.

CLINICAL PERSPECTIVE

What is new? What are the clinical implications?

Value of different CTO scoring systems in predicting procedural success in coronary chronic total occlusion intervention in Egyptian patients

BACKGROUND

Chronic total occlusion (CTO) lesions in coronary arteries pose a significant challenge for coronary interventionists, often leading to referrals for coronary artery bypass graft surgery (CABG). Successful percutaneous coronary intervention (PCI) for CTOs requires accurate assessment of procedural potential. This study, comprising 100 Egyptian patients aged 37-81, compares the predictive efficacy of various CTO scoring systems in PCI success determination. Patients with CTO in at least one coronary artery, planned for elective PCI based on objective evidence of ischemia, were included. Experienced operators performed PCI, recording procedural variables, and assessing complications. Logistic regression analysis revealed an inverse linear relationship between success rates and score values across all systems.

RESULTS

Although, the predictive capacity of the scores was similar, with slight differences. The Euro CTO (CASTLE) score10 exhibited superior predictive efficacy, followed by the CL score9, while PROGRESS8 and J-CTO7 scores showed lower significance. ORA CTO11 score demonstrated intermediate predictive ability, and PROGRESS score8 had the least predictive value.

CONCLUSION

The CASTLE score10 proved most effective in predicting PCI success for CTO cases in Egyptian patients, with operators advised to choose scoring systems based on experience and case characteristics. Proper planning remains crucial for optimizing success rates in CTO PCI procedures, irrespective of the scoring system employed.

Clinical results of percutaneous coronary intervention in chronic total occlusions of the right coronary artery

INTRODUCTION AND OBJECTIVES

Coronary chronic total occlusions (CTOs) of the right coronary artery (RCA) are a relatively common finding in the context of coronary angiography. However, the benefit of revascularization remains controversial.

METHODS

A single-center retrospective cohort analysis prospectively collected outcomes of CTO patients undergoing percutaneous coronary intervention (PCI) in 2019 and 2020. Patients were divided into two groups according to the CTO vessel treated (left coronary artery [LCA]-CTO or RCA-CTO). The primary outcome was defined as the recurrence of angina and/or heart failure (HF) symptoms and secondary outcomes were myocardial infarction (MI) and all-cause mortality.

RESULTS

A total of 177 patients (82.5% male) were included in the analysis, with a mean age of 65±11 years. The primary outcome occurred in 28 (16.6%) patients and was significantly more frequent in RCA-CTO patients (19, 24.7%, p=0.010) in a mean follow-up of 18 months. This was mainly driven by recurrence of HF symptoms (12, 15.6%, p=0.013). Treated RCA-CTO was an independent predictor of the primary outcome (p=0.019, HR 2.66, 95% CI 1.17-6.05). MI and mortality rates were no different between groups (RCA-CTO with 1.3%, p=0.361 and 2.6%, p=0.673, respectively, on survival analysis). Left ventricular ejection fraction was an independent predictor of mortality (p=0.041, HR 0.93, 95% CI 0.87-0.99).

CONCLUSIONS

Revascularization of CTO lesions by PCI was associated with low rates of symptom recurrence, and clinical outcomes showed no differences regardless of which artery was treated. Recanalization of RCA-CTO was less beneficial in reducing the recurrence of HF symptoms.

A non-interventional cardiologist's guide to coronary chronic total occlusions

Coronary chronic total occlusions (CTO) are present in up to one-third of patients with coronary artery disease (CAD). It is thus essential for all clinical cardiologists to possess a basic awareness and understanding of CTOs, including optimal evaluation and management. While percutaneous coronary intervention (PCI) for CTO lesions has many similarities to non-CTO PCI, there are important considerations pertaining to pre-procedural evaluation, interventional techniques, procedural complications, and post-procedure management and follow-up unique to patients undergoing this highly specialized intervention. Distinct from other existing topical reviews, the current manuscript focuses on key knowledge relevant to non-interventional cardiologists.

Evaluation and management of patients with coronary chronic total occlusions considered for revascularisation. A clinical consensus statement of the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the ESC, the European Association of Cardiovascular Imaging (EACVI) of the ESC, and the ESC Working Group on Cardiovascular Surgery

Chronic total occlusions (CTOs) of coronary arteries can be found in the context of chronic or acute coronary syndromes; sometimes they are an incidental finding in those apparently healthy individuals undergoing imaging for preoperative risk assessment. Recently, the invasive management of CTOs has made impressive progress due to sophisticated preinterventional assessment, including advanced non-invasive imaging, the availability of novel and dedicated tools for CTO percutaneous coronary intervention (PCI), and experienced interventionalists working in specialised centres. Thus, it is crucial that referring physicians who see patients with CTO be aware of recent developments and of the initial evaluation requirements for such patients. Besides a careful history and clinical examination, electrocardiograms, exercise tests, and non-invasive imaging modalities are important for selecting the patients most suitable for CTO PCI, while others may be referred to coronary artery bypass graft or optimal medical therapy only. While CTO PCI improves angina and reduces the use of antianginal drugs in patients with symptoms and proven ischaemia, hibernation and/or wall motion abnormalities at baseline or during stress, the effect of CTO PCI on major cardiovascular events is still controversial. This clinical consensus statement specifically focuses on referring physicians, providing a comprehensive algorithm for the preinterventional evaluation of patients with CTO and the current evidence for the clinical effectiveness of the procedure. The proposed care track has been developed by members and with the support of the European Association of Percutaneous Cardiovascular Interventions (EAPCI), the European Association of Cardiovascular Imaging (EACVI), and the European Society of Cardiology (ESC) Working Group on Cardiovascular Surgery.

Deep Learning-based Prediction of Percutaneous Recanalization in Chronic Total Occlusion Using Coronary CT Angiography

Background CT is helpful in guiding the revascularization of chronic total occlusion (CTO), but manual prediction scores of percutaneous coronary intervention (PCI) success have challenges. Deep learning (DL) is expected to predict success of PCI for CTO lesions more efficiently. Purpose To develop a DL model to predict guidewire crossing and PCI outcomes for CTO using coronary CT angiography (CCTA) and evaluate its performance compared with manual prediction scores.

MATERIALS AND METHODS

Participants with CTO lesions were prospectively identified from one tertiary hospital between January 2018 and December 2021 as the training set to develop the DL prediction model for PCI of CTO, with fivefold cross validation. The algorithm was tested using an external test set prospectively enrolled from three tertiary hospitals between January 2021 and June 2022 with the same eligibility criteria. All participants underwent preprocedural CCTA within 1 month before PCI. The end points were guidewire crossing within 30 minutes and PCI success of CTO.

Results A total of 534 participants (mean age, 57.7 years ± 10.8 [SD]; 417 [78.1%] men) with 565 CTO lesions were included. In the external test set (186 participants with 189 CTOs), the DL model saved 85.0% of the reconstruction and analysis time of manual scores (mean, 73.7 seconds vs 418.2-466.9 seconds) and had higher accuracy than manual scores in predicting guidewire crossing within 30 minutes (DL, 91.0%; CT Registry of Chronic Total Occlusion Revascularization, 61.9%; Korean Multicenter CTO CT Registry [KCCT], 68.3%; CCTA-derived Multicenter CTO Registry of Japan (J-CTO), 68.8%; P < .05) and PCI success (DL, 93.7%; KCCT, 74.6%; J-CTO, 75.1%; P < .05). For DL, the area under the receiver operating characteristic curve was 0.97 (95% CI: 0.89, 0.99) for the training test set and 0.96 (95% CI: 0.90, 0.98) for the external test set. Conclusion The DL prediction model accurately predicted the percutaneous recanalization outcomes of CTO lesions and increased the efficiency of noninvasively grading the difficulty of PCI. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Pundziute-do Prado in this issue.

Three-year outcomes of A Randomized Multicentre Trial Comparing Revascularization and Optimal Medical Therapy for Chronic Total Coronary Occlusions (EuroCTO)

BACKGROUND

Percutaneous coronary intervention (PCI) for chronic total coronary occlusions (CTO) improves clinical symptoms and quality of life. The longer-term safety of PCI compared to optimal medical therapy (OMT) remains uncertain.

AIMS

We sought to evaluate the long-term safety of PCI for CTO in a randomised trial as compared to OMT.

METHODS

A total of 396 patients with a symptomatic CTO were enrolled into a randomised, multicentre clinical trial comparing PCI and OMT. Half of the patients had a single CTO; the others had multivessel disease. Non-CTO lesions were treated prior to randomisation (2:1 ratio). During follow-up, crossover from OMT to PCI occurred in 7.3% (1 year) and 17.5% (3 years) of patients.

RESULTS

At 3 years, the incidence of cardiovascular death or nonfatal myocardial infarction was not significantly different between the groups (OMT 3.7% vs PCI 6.2%; p=0.29). By per-protocol analysis, the difference remained non-significant (OMT 5.7% vs PCI 4.7%; p=0.67). Overall, major adverse cardiovascular events (MACE) were more frequent with OMT (OMT 21.2% vs PCI 11.2%), largely because of ischaemia-driven revascularisation. The rates of stroke or hospitalisation for bleeding were not different between the groups.

CONCLUSIONS

At 3 years there was no difference in the rate of cardiovascular death or myocardial infarction between PCI or OMT among patients with a remaining single coronary CTO. The MACE rate was higher in the OMT group due largely to ischaemia-driven revascularisation. CTO PCI appears to be a safe option for patients with a single remaining significant coronary CTO. CinicalTrials.gov: NCT01760083.

Association of Successful Percutaneous Revascularization of Chronic Total Occlusions With Quality of Life: A Systematic Review and Meta-Analysis

Importance

Chronic total occlusion percutaneous coronary intervention (CTO-PCI) is not usually offered because of skepticism about long-term clinical benefits.

Objective

To assess the association of successful CTO-PCI with quality of life by analyzing the relevant domains of the Seattle Angina Questionnaire (SAQ).

Data Sources

PubMed, EMBASE, Web of Science, Google Scholar, and Cochrane databases were searched to identify randomized trials and observational studies specifically addressing quality of life domains of SAQ from January 2010 to June 2022.

Study Selection

Studies included reporting SAQ metrics such as angina frequency, physical limitation, and quality of life, before and after CTO-PCI.

Data Extraction and Synthesis

The present study was performed according to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements, in which fixed-effect or random-effect models with generic inverse-variance weighting depending on statistical homogeneity were applied. Data were extracted by 3 independent reviewers.

Outcomes and Measures

The primary outcome was angina frequency; physical limitation and quality of life were assessed as secondary outcomes.

Results

Seven prospective randomized or observational studies (2500 patients) were included, with a mean (SD) participant age of 61.2 (2.1) years. CTO-PCI was associated with significantly improved quality-of-life metrics during a mean (SD) follow-up of 14.8 (16.3) months. In patients with successful procedures, angina episodes became less frequent (mean [SD] difference for SAQ angina frequency of 12.9 [3.1] survey points [95% CI, 7.1-19.8 survey points]; standardized mean difference was 0.54 [95% CI, 0.21-0.92]; P = .002; I2 = 86.4%) and they experienced less physical activity limitation (mean [SD] difference for SAQ physical limitation of 9.7 [6.2] survey points [95% CI, 3.5-16.2 survey points]; standardized mean difference was 0.42 [95% CI, 0.24-0.55]; P < .001; I2 = 20.9%), and greater quality-of-life domain (mean [SD] difference for SAQ quality of life of 14.9 [3.5] survey points [95% CI, 7.7-22.5 survey points]; standardized mean difference was 0.41 [95% CI, 0.25-0.61]; P < .001; I2 = 58.8%) compared with patients with optimal medical therapy or failed procedure. Furthermore, follow-up duration (point estimate, 0.03; 95% CI, 0.01-0.04; P = .01) was associated with a significant decrease in angina frequency in meta-regression analysis.

Conclusions and Relevance

In this systematic review and meta-analysis examining quality of life following CTO-PCI, successful procedures were associated with improved quality-of-life parameters compared with patients on optimal medical therapy or after failed CTO-PCI. These findings suggest support for using PCI to treat CTOs in symptomatic patients unresponsive to medical treatment.

The association of collaterals with myocardial ischemia and viability in chronic total occlusions

Collateral development in chronic total occlusions (CTO) is crucial to perfuse the distal myocardium and its angiographic evaluation is frequently used to assess the need for revascularization. We aimed to analyse the association between the presence of ischemia and hibernating myocardium, evaluated by cardiac [¹³ N]NH3/2-[¹⁸ F]FDG PET-CT, and the angiographic characterization of the collateral circulation. Prospective study including patients with a CTO who underwent a [¹³ N]NH3 and, when deemed necessary, 2-[¹⁸ F]FDG PET-CT. Well developed (WD) collaterals were defined as a concomitant angiographic Rentrop grade 3 and Werner collateral connection score 2 or 3, whereas the remaining as poorly developed (PD). 2% thresholds used to identify prognostic benefit of revascularization were applied: ischemia > 10% and hibernating myocardium > 7%. Fifty-nine patients (age 62.9±9.1 years, 58 male) were recruited, WD collaterals were present in 28 (47.5%). No significant differences were found in ischemia (WD 6.4±4.3 vs. PD 7.0±4.1, p = 0.64) and hibernation (WD 1.8±1.9 vs. PD 3.1±3.3, p = 0.18) scores. Most CTO territories demonstrated ischemia, but only 19 (46.3%) were associated with an area > 10% (WD 47.6% vs. PD 45.0%, p = 0.58). Scared non-viable myocardium was limited to 9 (15.3%) patients and was not associated with PD collaterals. Hibernating myocardium was frequent (54.2%), but just 6 (10.2%) CTO patients had an area of > 7% (WD 3.6% vs. PD 16.1%, p = 0.20). Collateral assessment by angiography has a poor association with the ischemic burden and hibernation state of CTO territories. Myocardial viability was present even in most CTO with angiographic PD collaterals.

The Role of Multimodality Imaging for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusions

Background

Percutaneous coronary intervention (PCI) of Chronic total occlusions (CTOs) has been traditionally considered a challenging procedure, with a lower success rate and a higher incidence of complications compared to non-CTO-PCI. An accurate and comprehensive evaluation of potential candidates for CTO-PCI is of great importance. Indeed, assessment of myocardial viability, left ventricular function, individual risk profile and coronary lesion complexity as well as detection of inducible ischemia are key information that should be integrated for a shared treatment decision and interventional strategy planning. In this regard, multimodality imaging can provide combined data that can be very useful for the decision-making algorithm and for planning percutaneous CTO recanalization.

Aims

The purpose of this article is to appraise the value and limitations of several non-invasive imaging tools to provide relevant information about the anatomical characteristics and functional impact of CTOs that may be useful for the pre-procedural assessment and follow-up of candidates for CTO-PCI. They include echocardiography, coronary computed tomography angiography (CCTA), nuclear imaging, and cardiac magnetic resonance (CMR). As an example, CCTA can accurately delineate CTO location and length, distal coronary bed, vessel tortuosity and calcifications that can predict PCI success, whereas stress CMR, nuclear imaging and stress-CT can provide functional evaluation in terms of myocardial ischemia and viability and perfusion defect extension.

Circulating Chromogranin B Is Associated With Left Ventricular Functional Recovery After Successful Recanalization of Chronic Total Occlusion

Background: Chromogranin B (CgB) is increased in heart failure and proportionate to disease severity. We investigated whether circulating CgB level is associated with left ventricular (LV) functional recovery potential after successful recanalization of chronic total occlusion (CTO).

Methods: Serum levels of CgB were assayed in 53 patients with stable angina with LV functional recovery [an absolute increase in LV ejection fraction (EF) of ≥5%] and 53 age- and sex-matched non-recovery controls after successful recanalization of CTO during 12-month follow-up.

Results: We found that CgB level was significantly lower in the recovery group than in the non-recovery group (593 [IQR 454–934] vs. 1,108 [IQR 696–2020] pg/ml, P < 0.001), and that it was inversely correlated with changes in LVEF (Spearman's r = −0.31, P = 0.001). Receiver operating characteristic (ROC) analysis showed that the area under the curve of CgB for predicting LVEF improvement was 0.76 (95% CI 0.664–0.856), and that the optimal cutoff value was 972.5 pg/ml. In multivariate analyses, after adjusting for confounding factors, high CgB level remained an independent determinant of impaired LV functional recovery after CTO recanalization. LV functional improvement appeared to be more responsive to CgB in patients with poor than with good coronary collaterals.

Conclusions: Elevated circulating CgB level confers an increased risk of impaired LV functional recovery after successful recanalization of CTO in patients with stable coronary artery disease.

The Comparison of Long-Term Outcome Between Patients with Single and Multiple Coronary Chronic Total Occlusions After Percutaneous Coronary Intervention

Background

Rapid advancements in percutaneous coronary intervention (PCI) have improved the outcome of chronic coronary total occlusions (CTOs); however, data regarding the difference in long-term outcomes in stable coronary artery disease (CAD) patients with single and multiple CTOs who underwent PCI are scarce. This study aimed to compare the long-term outcomes of patients with multiple CTOs and single CTO after PCI.

Methods

This study cohort included stable CAD patients who were diagnosed with CTO and treated with PCI from a single center. The primary endpoint was all-cause death.

Results

We retrospectively reviewed 670 consecutive patients with CTO-PCI. Among them, 539 patients had a single CTO, and 131 (19.7%) patients had multiple (at least two) CTOs. CTO revascularization was achieved in 470 (70.1%) patients. After a median follow-up duration of 33.7 months, the cumulative all-cause mortality (p = 0.037) and cardiac mortality (p = 0.003) were higher in patients with multiple CTOs than in those with a single CTO. In the multivariable model, multiple CTOs and left ventricular ejection fraction (LVEF) less than 40% were independent predictors for cardiac death (adjusted hazard ratio (HR) 2.53; P = 0.013 and adjusted HR 3.95; P < 0.001), while age older than 65 and LVEF less than 40% were independent predictors for all-cause death in CTO-PCI patients (adjusted hazard ratio (HR) 1.84; P = 0.035 and adjusted HR 2.54; P = 0.001).

Conclusion

In CTO-PCI patients, long-term survival was associated with multiple CTOs, age and LVEF, but not with CTO revascularization.

Preserved myocardial viability in patients with chronic total occlusion of a single coronary artery

OBJECTIVE

To assess the benefits of coronary collateral circulation on myocardial perfusion, viability and function in patients with total occlusion of a single coronary artery using the 99mTc-sestamibi SPECT and 18F-fluorodeoxyglucose PET.

METHODS

164 Consecutive patients were included who underwent coronary angiography results exhibited total occlusion of a single coronary artery and received 99mTc-MIBI SPECT and 18F-FDG PET within 90 days of angiography. Myocardial perfusion and viability in patients with collateral circulation and those without it were compared. Long-term follow-up was performed through a review of patient clinical records.

RESULTS

Collateral circulation was present in 56 patients (34%) and absent in 108 patients (66%). The total perfusion defect size in patients with collateral circulation decreased when compared to those without (30% ± 13% to 35% ± 14%, P < .05). The myocardial viability was 22% ± 12% in patients with collateral circulation, and 12% ± 9% in those without (P < .001). The left ventricular ejection fraction was higher, and the end-diastolic and end-systolic left ventricular volumes were lower in patients with collateral circulation (39% ± 11%, 138 ± 66, 89 ± 57) compared to patients without collateral circulation (31% ± 9%, 177 ± 55, 125 ± 48, all P < .001, respectively). Multi-factor logistic regression identified that concerning the variables of sex, age, viable myocardium, collateral circulation, treatment type and others, only treatment type was significantly associated with therapeutic effects (OR 3.872, 95% CI 1.915-7.830, P < .001).

CONCLUSION

Collateral circulation can preserve resting myocardial blood perfusion and myocardial viability, and help maintain the function of the left ventricular myocardium. The appropriate treatment strategy will have a substantial impact on the therapeutic outcome.

A Novel Clinical Scoring Model for Interventional Therapy in Chronic Total Occlusion of the Coronary Artery

Objective

With the rapid development of technology and experience, the current percutaneous coronary intervention of chronic total occlusion (CTO-PCI) preoperative scoring model needs to be updated. This study aimed to evaluate the clinical value of the operator-CTO score in predicting the outcome of interventional therapy for chronic total occlusion of the coronary artery.

Methods

The data of 144 lesions in 130 patients with CTO were analyzed prospectively. The CTO procedures were performed by 10 operators with different skills and experiences. Before the procedures, J-CTO, progress, ORA, recharge, and operator-CTO scores were determined. Then, the clinical, imaging, and procedural data of patients in different operator-CTO score groups and between different operators were compared. The final focus was on comparing the predictive ability of each score on the outcome of CTO-PCI.

Results

The overall technical and procedural success rates were 90.9% and 88.9%, respectively. A decreasing trend in the technical success of CTO-PCI was observed according to the operator-CTO score hierarchy of “easy (≤2 points), moderate (3 points), difficult (4 points), and extremely difficult (≥5 points)” (99.0%, 87.5%, 53.8%, and 25.0%, respectively). All five scoring models were well calibrated, and the area under the curve (AUC) for the operator-CTO score was 0.901 (95% CI: 0.821–0.982, P < 0.01), larger than the AUC for the remaining four scoring models, showing excellent ability to predict technical outcomes.

Conclusion

The operator-CTO score is a new clinical scoring tool that can predict the outcome of CTO-PCI and can be used to grade the difficulty of the procedure, with the potential to work well with a broad group of operators.

Impact of chronic kidney disease in chronic total occlusion management and clinical outcomes

BACKGROUND

Data on the impact of chronic kidney disease (CKD) on clinical outcomes in chronic total occlusion (CTO) patients is scarce, and the optimal treatment strategy for this population is not well established. This study aims to compare differences in CTO management and long-term clinical outcomes, including all-cause and cardiac mortalities, according to baseline glomerular filtration rate (GFR).

METHODS

All patients with at least one CTO diagnosed in our center between 2010 and 2014 were included. Demographic and clinical data were registered. All-cause and cardiac mortalities were assessed during a median follow-up of 4.03 years (IQR 2.6-4.8). Clinical outcomes were compared between patients with CKD (GFR < 60 mL/min/1.73 m²) and without CKD (GFR ≥ 60 mL/min/1.73 m²).

RESULTS

A total of 1248 patients (67.3 ± 10.9 years; 32% CKD) were identified. CKD patients were older and had a higher prevalence of hypertension, type 2 diabetes, peripheral arterial disease, and severe left ventricular dysfunction compared to patients with normal renal function (p < 0.05). Subjects with renal dysfunction were more often treated with MT alone, compared to patients without CKD (63% vs 45%; p < 0.001), who were more likely to undergo PCI or surgery. During follow-up, 386 patients [31%] died. CKD patients had a higher rate of all-cause and cardiac mortalities compared to patients without CKD (p < 0.001). The independent predictors for all-cause mortality were age, GFR < 60 mL/min/1.73 m², Syntax Score I, and successful revascularization of the CTO (CABG or PCI-CTO). Among patients with CKD, advanced age, eGFR <30 mL/min/1.73 m², and CTO successful revascularization were predictors of all-cause mortality.

CONCLUSIONS

Patients with CKD were more often treated with MT alone. At long-term follow-up, revascularization of the CTO is associated with lower all-cause and cardiac mortalities in this population.

Effect of Coronary CTA on Chronic Total Occlusion Percutaneous Coronary Intervention: A Randomized Trial

OBJECTIVES

The purpose of this study was to test whether the success rate of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) increased with pre-procedural coronary computed tomography angiography (CTA).

BACKGROUND

Coronary CTA provides valuable information before and during CTO-PCI. However, there are no randomized data that explore whether coronary CTA increases its success rate.

METHODS

In this multicenter, randomized trial, a total of 400 patients with CTO were randomized to receive PCI with pre-procedural coronary CTA (coronary CTA-guided group; n = 200) or without coronary CTA (angiography-guided group; n = 200) between January 2014 and September 2019. The primary endpoint was the successful recanalization rate, a final TIMI (Thrombolysis In Myocardial Infarction) grade ≥2, and ≤30% residual stenosis on the final angiogram.

RESULTS

A total of 10 operators performed PCI. Successful recanalization was achieved in 187 patients (93.5%) in the coronary CTA-guided group and in 168 patients (84.0%) in the angiography-guided group (absolute difference, 9.5% [95% confidence interval: 3.4% to 15.6%]; p = 0.003). When comparing the success rates according to the Multicenter CTO Registry of Japan score (J-CTO), the coronary CTA guidance was favored over the angiography-guidance in the subset of J-CTO ≥2 versus in the subset of J-CTO <2 (p interaction = 0.035). Coronary perforations occurred in 2 (1%) and 8 patients (4%) in the coronary CTA- and angiography-guided groups, respectively (p = 0.055). Periprocedural myocardial infarction was not observed in the coronary CTA-guided group, whereas it occurred in 4 patients (2%) in the angiography-guided group (p = 0.123). Total procedure and fluoroscopic times were not different. There were no differences between the groups in the occurrences of cardiac death, target vessel-related myocardial infarction, or target-vessel revascularization at 1 year.

CONCLUSIONS

Pre-procedural coronary CTA-guidance for CTO resulted in higher success rates with numerically fewer immediate periprocedural complications such as coronary perforations or periprocedural myocardial infarction than angiography guidance. Higher success rates were more prominently observed in patients with CTO who had a high J-CTO score than those who did not. (Role of CT Scan for the Successful Recanalization of Chronic Total Occlusion; a Randomized Comparison Between 3D CT-guided PCI vs. Conventional Treatment [CT-CTO Trial]; NCT02037698).

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

Background/aim

Successful 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.

Methods

In 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.

Results

Pathological 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).

Conclusion

Well-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.

Procedures for chronic total occlusion: when are they recommended and when not

Coronary chronic total occlusion (CTO) produces an important clinical problem, often treated with medical therapy or coronary artery bypass grafting. Recent clinical studies, both registries and randomized trials, demonstrated that percutaneous coronary interventions (PCI), could provide a valid therapeutic option. Nonetheless, significant reduction in all-cause mortality, cardiac mortality, myocardial infarction, MACE, and MACCE has not been demonstrated in the subgroups analysis of randomized trials. These analyses suggest that PCI for CTO should be reserved for patients with angina or with large areas of the myocardium with reversible ischaemia. Large randomized studies should search for a personalized approach, considering the risks and complexity of PCI in CTO, which should mainly consider the extension of the ischaemia and the viability of the myocardium.

The Canadian Contribution to Science, Techniques, Technology, and Education in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions are considered the most complex coronary lesions in interventional cardiology. This article reviews the Canadian clinical and academic contributions to this field, including innovative procedural techniques, teaching and proctoring, clinical research, and the development of novel tools and therapies.

Non-pharmacological Treatment of Refractory Angina and Microvascular Angina

Refractory angina (RA) is defined as debilitating anginal symptoms despite the optimal guideline-directed combination of medical, percutaneous, and surgical therapies. Often referred to as “no option”, these patients represent a significant unmet clinical need for healthcare institutions. Due to the ageing of the population, and increased survival from coronary artery disease, the number of patients with RA is expected to rise exponentially. Despite the developments of novel technologies for the treatment of RA, none of them found wide clinical application (to date). Microvascular dysfunction, alone or in combination with epicardial coronary disease, is thought to contribute significantly to refractory angina. However, most of the techniques developed to improve RA symptoms have not been tested specifically on patients with microvascular dysfunction. This review discusses the recent developments in the treatment of RA, and gives some perspectives on the future of these techniques.

A prospective evaluation of a redefined version of the "minimalistic hybrid approach" algorithm for percutaneous coronary chronic total occlusion revascularization

OBJECTIVES

Aim of this study is to prospectively assess the feasibility of the "Minimalistic Hybrid Approach" (MHA) algorithm for chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

BACKGROUND

We recently described the MHA, with focus on the classic hybrid strategies (antegrade wire escalation [AWE] or retrograde wire escalation [RWE], antegrade dissection-re-entry [ADR] or retrograde dissection-re-entry [RDR]), and also on access site (favoring "wrist" approach: radial, ulnar, and distal radial), introducer French size (favoring 6 French catheters) and nonroutine initial use of dual injection.

METHODS

The MHA was prospectively attempted in 56 consecutive CTO PCI in 54 patients. Technical success was defined as the achievement of TIMI 3 antegrade flow with residual stenosis <30%, procedural success was defined as technical success without in-hospital major adverse cardiovascular events.

RESULTS

Mean Japanese-CTO (J-CTO) score was 2.04 ± 0.95(J-CTO score ≥ 3 in 30.4%). The lesion-based technical and procedural success were 94.6%(53/56:three failures, two in the same patient) and 91.1%(51/56:three failures, one tamponade requiring pericardiocentesis and one periprocedural infarction), the patient-based successes were: technical 98.1%(53/54) and procedural 94.4%(51/54). In 34 procedures (60.7%), the approach was single catheter (always trans-wrist besides one femoral). Out of the 22(39.3%) lesions approached with dual catheters, one was bi-femoral, the rest was bi-wrist. In 29 cases (51.8%) AWE represented the successful technique, ADR in 5(8.9%) and retrograde in 19(33.9%); 3(5.4%) were failures.

CONCLUSIONS

The current study shows that the MHA algorithm is feasible in almost every CTO lesion and it can lead to extremely successful results once applied by operators well acquainted with the wrist approach and with established experience using the full spectrum of the hybrid algorithm techniques.

SPECT Versus PET Myocardial Perfusion Imaging in Patients with Equivocal CT

PURPOSE OF REVIEW

The most pertinent clinical question in post-coronary computed tomography angiography (CCTA) patients is the assessment of the physiological significance of an anatomically identified stenosis. The clinical application of radionuclide MPI using single-photon emission computed tomography (SPECT) versus positron emission tomography (PET) in the evaluation and management of patients with an inconclusive CCTA is reviewed using a case-based approach.

RECENT FINDINGS

Recent evidence suggests that CCTA is the most sensitive non-invasive test to exclude angiographic CAD and may be an effective first-line test especially among symptomatic low-intermediate risk patients. However, in the presence of angiographic atherosclerosis, its specificity and positive predictive value for identifying flow-limiting stenosis are modest. Radionuclide myocardial perfusion imaging offers accurate quantitative assessment of myocardial ischemia, which helps with risk stratification and patient management especially the potential need for revascularization. Routine accurate quantifications of myocardial blood flow and flow reserve are major advantages of PET MPI, which are especially useful when used in patients at intermediate-high clinical risk.

CASTLE score versus J-CTO score for the prediction of technical success in chronic total occlusion percutaneous revascularisation

AIMS

We sought to compare the efficiency of the novel EuroCTO (CASTLE) score with the commonly used Multicentre CTO Registry in Japan (J-CTO) score in predicting procedural success of percutaneous coronary intervention (PCI) for coronary chronic total occlusions (CTOs).

METHODS AND RESULTS

We evaluated 660 consecutive CTO PCIs (mean age 66±11 years, 84% male). The mean J-CTO and EuroCTO (CASTLE) scores were 1.86±1.2 and 1.74±1.2, respectively. Antegrade wire escalation, antegrade dissection re-entry and retrograde approach were used in 82%, 14% and 37% of cases, respectively. Receiver operating characteristic analysis demonstrated equal overall discriminatory capacity between the two scores (AUC 0.698, 95% CI: 0.653-0.742, p<0.001 for J-CTO vs AUC 0.676, 95% CI: 0.627-0.725, p<0.001 for EuroCTO; AUC difference: 0.022, p=0.5). However, for more complex procedures (J-CTO ≥3 or EuroCTO [CASTLE] ≥4]), the predictive capacity of the EuroCTO (CASTLE) score appeared superior (AUC 0.588, 95% CI: 0.509-0.668, p=0.03 for EuroCTO [CASTLE] score vs AUC 0.473, 95% CI: 0.393-0.553, p=NS for the J-CTO score, AUC difference: 0.115, p=0.04).

CONCLUSIONS

In this study, the novel EuroCTO (CASTLE) score was comparable to the J-CTO score in predicting CTO PCI outcome with a superior discriminatory capacity for the more complex cases.

Echocardiographic assessment of left ventricular function recovery post percutaneous coronary intervention of chronic total occlusions in patients with low and mid-range left ventricular ejection fractions

OBJECTIVES

Coronary chronic total occlusion (CTO) is a frequent condition encountered in cardiac catheterization laboratory with a prevalence of about 20%. Through literature, data are scarcely reported regarding the left ventricular (LV) function recovery post CTO percutaneous coronary intervention (PCI) in patients with low (<40%) and mid-range (40%-49%) LV ejection fraction (LVEF). The aim of this study was to assess the echocardiographic outcomes of CTO patients with low and mid-range LVEF successfully revascularized at 6-month follow-up.

METHODS

This prospective study included 75 patients with at least one CTO of an epicardial coronary artery proved by previous diagnostic coronary angiography with PCI attempt indication, and successfully revascularized. They were equally divided according to LVEF into three groups, and echocardiographic remodeling indices were assessed at baseline and 6 months post PCI.

RESULTS

Our study showed significant improvement of LVEF, S-wave velocity by tissue doppler imaging (TDI), LV wall-motion score (LVWMS), and LV systolic sphericity index (LVSIS) 6 months post CTO PCI in low LVEF group, and a significant improvement in LVEF, S-wave velocity, and LVWMS in mid-range LVEF group (P < .05). The delta change in LVEF was significantly more in low LVEF group, compared to the other two groups (F = 4.739, P < .05).

CONCLUSION

Successful CTO PCI in patients with low and mid-range LVEF is associated with significant improvement of LVEF and other indices of myocardial remodeling after 6 months of follow-up.

A randomized multicentre trial to compare revascularization with optimal medical therapy for the treatment of chronic total coronary occlusions

Aims

The clinical value of percutaneous coronary intervention (PCI) for chronic coronary total occlusions (CTOs) is not established by randomized trials. This study should compare the benefit of PCI vs. optimal medical therapy (OMT) on the health status in patients with at least one CTO.

Method and results

Three hundred and ninety-six patients were enrolled in a prospective randomized, multicentre, open-label, and controlled clinical trial to compare the treatment by PCI with OMT with a 2:1 randomization ratio. The primary endpoint was the change in health status assessed by the Seattle angina questionnaire (SAQ) between baseline and 12 months follow-up. Fifty-two percent of patients have multi-vessel disease in whom all significant non-occlusive lesions were treated before randomization. An intention-to-treat analysis was performed including 13.4% failed procedures in the PCI group and 7.3% cross-overs in the OMT group. At 12 months, a greater improvement of SAQ subscales was observed with PCI as compared with OMT for angina frequency [5.23, 95% confidence interval (CI) 1.75; 8.71; P = 0.003], and quality of life (6.62, 95% CI 1.78-11.46; P = 0.007), reaching the prespecified significance level of 0.01 for the primary endpoint. Physical limitation (P = 0.02) was also improved in the PCI group. Complete freedom from angina was more frequent with PCI 71.6% than OMT 57.8% (P = 0.008). There was no periprocedural death or myocardial infarction. At 12 months, major adverse cardiac events were comparable between the two groups.

Conclusion

Percutaneous coronary intervention leads to a significant improvement of the health status in patients with stable angina and a CTO as compared with OMT alone.

Trial registration

NCT01760083.

Health Status Benefits of Successful Chronic Total Occlusion Revascularization Across the Spectrum of Left Ventricular Function: Insights From the OPEN-CTO Registry

OBJECTIVES

This study sought to describe the association between chronic total occlusion (CTO) revascularization (CTO percutaneous coronary intervention [PCI]) and health status in patients with and without cardiomyopathy.

BACKGROUND

Prior PCI trials for cardiomyopathy have excluded CTO patients. Whether patients with reduced left ventricular ejection fraction (LVEF) receive similar health status benefit from CTO-PCI compared with patients with normal LVEF is unclear.

METHODS

We assessed health status change, using the Seattle Angina Questionnaire (SAQ) Summary, SAQ Angina Frequency, and Rose Dyspnea Scale scores, among patients undergoing successful CTO PCI in the OPEN-CTO (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion) Registry. Participants were classified by LVEF (normal, ≥50%; mild-moderate, 30% to 49%; and severe, <30%), with higher SAQ and lower Rose Dyspnea Scale scores indicating better health status. Differences in 1-year outcomes were compared using hierarchical multivariable regression.

RESULTS

Of 762 patients, 506 (66.4%), 193 (25.3%), and 63 (8.3%) had normal, mild-moderate, and severely reduced LVEF. SAQ Summary score improvements were observed in each group (27.1 ± 20.4, 26.7 ± 21.2, and 20.3 ± 18.1, respectively). Compared with patients with LVEF ≥50%, those with LVEF <30% had less improvement in SAQ Summary Score (-5.2 points; 95% confidence interval: -9.0 to -1.5; p = 0.01) and Rose Dyspnea Scale (+0.5 points; 95% confidence interval: 0.1 to 0.8; p = 0.01), with no difference in odds of angina (odds ratio: 1.3; 95% confidence interval: 0.6 to 3.0; p = 0.48). Health status improvement was similar between patients with LVEF ≥50% and LVEF 30% to 49%.

CONCLUSIONS

Although health status improvement was less in patients with severely reduced LVEF compared with those with normal LVEF, each group experienced large health status improvements after CTO-PCI.

Current approaches for treatment of coronary chronic occlusions

Introduction: Coronary chronic total occlusions (CTO) represent a challenging subset in interventional cardiology.Areas covered: During the last decade, improvements in materials, techniques, and meticulous pre-procedural lesion assessment have increased the success rate in CTO lesions. Several scores have been developed to address overall lesion evaluation and help select the most appropriate treatment strategy. In addition, specific algorithms such as the hybrid algorithm have been introduced to provide a framework for CTO operators and a rapid management of the various challenging aspects of the procedure. The hybrid approach requires operator's ability to switch from one treatment strategy to another when the first one appears to be unsuccessful. Adequate training and operators' experience remain crucial to improve the likelihood of success.Expert opinion: The aim of this review is to provide insights and guidance for operators on current approaches for treatment of CTO and complication management.

Impact of chronic total occlusion on ventricular arrhythmia and mortality in ischaemic cardiomyopathy patient with implantable cardiac defibrillator: a meta-analysis

Background: Recent studies suggested that chronic total occlusion of the coronary artery increased risk of ventricular arrhythmia (VA) and all-cause mortality in ischaemic cardiomyopathy (ICM) patient who underwent implantable cardiac defibrillator (ICD) implantation. We aim to demonstrate an association between a presence of CTO and poor cardiovascular outcome in ICD implanted ICM patients. Objective: To examine the association between the presence of CTO and all-cause mortality in ICM with ICD implantation Methods: We comprehensively searched the databases of MEDLINE and EMBASE from inception to February 2018. The studies that reported appropriated shock and all-cause mortality in ICD implanted ICM patients, compared between patients with and without CTO of the coronary artery, were included for meta-analysis. Results: Five studies from 2015 to 2018 were included in this meta-analysis involving 1,095 subjects (505 CTO and 590 non-CTO). The presence of CTO was associated with increased incidence of VA (pooled risk ratio = 1.75, 95% confidence interval: 1.10-2.77, p = 0.01) and all-cause mortality (pooled risk ratio = 1.63, 95% confidence interval: 1.10-2.41, p = 0.001) in ICD implanted ICM patients. Conclusions: Presence of CTO of the coronary artery increased risk of VA and all-cause mortality in ICD implanted ICM patients up to 75% and 63%, respectively. Our study suggested that CTO is an independent predictor of unfavourable outcome and revascularised option should be considered in ICM patients with ICD.

Use of Coronary Computed Tomographic Angiography to Facilitate Percutaneous Coronary Intervention of Chronic Total Occlusions

Chronic total coronary occlusions (CTO) are found frequently in coronary artery disease; however, the technical challenge to open the occlusion by percutaneous coronary intervention is considerably higher than for nonocclusive lesions. The angiographic analysis is limited by the inability to visualize the occluded segment and requires a dual injection approach from donor and recipient vessel to assess the CTO. Therefore, imaging of the CTO by computed tomographic angiography can provide additional information on the vessel course within the CTO segment, specifically the degree and extent of calcification, and maybe even be superior to angiography to analyze the proximal cap morphology. This had been integrated in a score to predict the interventional success. This information provides a valuable means to better plan the procedure and the required strategy. In addition, an integration of the computed tomographic angiography is possible by synchronization with the gantry position and movement of the angiography system during percutaneous coronary intervention, illustrating the course of the occluded segment and possible obstacles in the way. It remains to be established which patient will most likely profit from this additional preprocedural examination involving increased radiation and contrast media exposure and institutional expenses.

Relationship of myocardial hibernation, scar, and angiographic collateral flow in ischemic cardiomyopathy with coronary chronic total occlusion

BACKGROUND

The relationship between myocardial viability and angiographic collateral flow is not fully elucidated in ischemic cardiomyopathy (ICM) with coronary artery chronic total occlusion (CTO). We aimed to clarify the relationship between myocardial hibernation, myocardial scar, and angiographic collateral flow in these patients.

METHODS AND RESULTS

Seventy-one consecutive ICM patients with 122 CTOs and 652 dysfunctional segments within CTO territories were retrospectively analyzed. Myocardial hibernation (perfusion-metabolism mismatch) and the extent of 18F-fluorodeoxyglucose (FDG) abnormalities were assessed using 99mTc-sestamibi and 18F-FDG imaging. Myocardial scar was evaluated by late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging. Collateral flow observed on coronary angiography was assessed using Rentrop classification. In these patients, neither the extent nor frequency of myocardial hibernation or scar was related to the status of collateral flow. Moreover, the matching rate in determining myocardial viability was poor between any 2 imaging indices. The extent of 18F-FDG abnormalities was linearly related to the extent of LGE rather than myocardial hibernation. Of note, nearly one-third (30.4%) of segments with transmural scar still had hibernating tissue. Hibernation and non-transmural scar had higher sensitivity (63.0% and 66.7%) than collateral flow (37.0%) in predicting global functional improvement.

CONCLUSIONS

Angiographic collateral cannot accurately predict myocardial viability, and has lower sensitivity in prediction of functional improvement in CTO territories in ICM patients. Hence, assessment of myocardial viability with non-invasive imaging modalities is of importance. Moreover, due to the lack of correlation between myocardial hibernation and scar, these two indices are complementary but not interchangeable.

Angiography and Percutaneous Coronary Intervention for Chronic Total Coronary Occlusion in Daily Practice (from a Large French Registry [CARDIO-ARSIF])

The aim of this study was to provide contemporary data on chronic total occlusion (CTO) prevalence and management in a large unselected population representing the daily activity of cathlabs, in the greater Paris area, and to compare percutaneous coronary intervention (PCI) features in patients with and without CTO. Procedures were collected from the CARDIO-ARSIF (Agence Régionale de Santé Ile de France) registry from 2012 to 2015. Patients with acute coronary syndrome or previous coronary artery bypass grafting were excluded. CTO features were assessed and PCIs with and without CTO were compared. Among 128,739 included patients, 10,468 (8.1%) had at least 1 CTO. Cardiovascular risk-factor burden was higher in the CTO group, which had more patients with multivessel disease (74% vs 24%) and with referral for interventional management (59% vs 33%). Of all PCIs during the study period, 5.7% involved a CTO; this proportion increased significantly over the study period. PCI success rate was 75.9% in the CTO group. CTO-PCI volume per center did not correlate with CTO-PCI success rate. In conclusion, CTO is common in patients who underwent scheduled coronary angiography. Invasive management is done more often in patients with than without CTO. The success rate of PCI in CTO is not associated with case volume per center.

Examining the Operator Learning Curve for Percutaneous Coronary Intervention of Chronic Total Occlusions

Background:

Advances in chronic total occlusion percutaneous coronary intervention (CTO PCI) techniques have led to increased procedural success rates among operators. While utilization of CTO PCI has disseminated widely, the learning curve for new operators has not been well-defined.

Methods:

Between July 2009 and December 2015, 93 875 CTO PCI cases were extracted from the CathPCI Registry. We delineated a cohort of new CTO operators performing <10 CTO PCI cases per given year. In-hospital outcomes for subsequent CTO PCIs were stratified by the number of prior cases accrued by each operator. Multivariable regression models were used to estimate differences in outcomes with increasing experience. The primary outcome was major adverse cardiovascular events defined as the composite of death, myocardial infarction, stroke, tamponade, or urgent coronary artery bypass grafting.

Results:

Among 70 916 cases performed by 7251 new operators, procedure success rate was 61.4% and major adverse cardiovascular event rate was 4.2%. Meanwhile, the rate of major bleeding was 4.0%, myocardial infarction 2.0%, mortality 0.6%, tamponade 0.3%, and renal failure 0.2%. Adjusted regression models demonstrated piecewise linear improvements in guidewire crossing, stent placement, and procedure success with accrued volume, albeit with increased contrast use, fluoroscopy time, and bleeding. Major adverse cardiovascular event rates were stable beyond the 12th case (odds ratio per 5 case increase 1.00; 95% CI, 0.98–1.03, P =0.7980).

Conclusions:

Among a large number of new CTO PCI operators in the United States, there exists an experiential learning curve for procedural success. However, there were higher rates of bleeding despite case experience, while major adverse cardiovascular events remained relatively unchanged after initiation.

Collateral Channel Size and Tortuosity Predict Retrograde Percutaneous Coronary Intervention Success for Chronic Total Occlusion

BACKGROUND

There is little evidence on how to select an interventional collateral channel (CC) in retrograde chronic total occlusion (CTO) percutaneous coronary intervention. We aimed to identify independent angiographic predictors of CC tracking and technical success in retrograde CTO percutaneous coronary intervention.

METHODS AND RESULTS

From January 2012 to December 2015, a total of 216 consecutive retrograde CTO percutaneous coronary intervention attempts by a high-volume operator in a tertiary university-affiliated hospital were enrolled. The clinical, angiographic, and procedural details were collected. The characteristics analyzed included channel type, size, tortuosity, angle of attack, length to emerging point, and the Multicenter CTO Registry of Japan score. The Multicenter CTO Registry of Japan score was 4.2±0.8. A total of 242 CCs were attempted for intervention. CC tracking success rate was 83.5%, and the technical success rate (per CC) was 81.4%. The per-patient technical success rate was 91.2%, and the major procedural complication rate was 4.6%. The atrioventricular groove, epicardial, and septal CCs were used in 36 (14.9%), 84 (34.7%), and 122 (50.4%) tracking attempts, respectively. In multivariable analysis, only large channel size and lack of tortuosity were significant independent predictors of CC tracking and technical success. A new scoring system was developed, while large size was given 1 point and lack of tortuosity was given 2 points. The receiver-operating characteristic area by the new model to predict CC tracking and technical success were 0.800 and 0.752, respectively.

CONCLUSIONS

In retrograde CTO percutaneous coronary intervention, only size and tortuosity of a CC are independent angiographic predictors of CC tracking and technical success.

Microcatheter collateral channel tracking failure in retrograde percutaneous coronary intervention for chronic total occlusion: incidence, predictors, and management

AIMS

This study sought to demonstrate the incidence, predictors, and management of microcatheter collateral channel (CC) tracking failure in retrograde percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) lesions.

METHODS AND RESULTS

Prospectively collected data from 371 consecutive retrograde CTO-PCI procedures between March 2015 and January 2018 were retrospectively analysed. The incidence of initial microcatheter CC tracking failure was 22.5% in 280 procedures with wire CC tracking success. For septal collaterals, CC grade 0-1 collaterals (odds ratio [OR]: 8.3; p<0.001), channel entry angle <90° (OR: 13.0; p=0.001), channel exit angle <90° (OR: 44.3; p=0.004), and Finecross MG as initial microcatheter (OR: 2.7; p=0.032) were independently related to initial microcatheter CC tracking failure. Meanwhile, the only predictor for epicardial collaterals was CC 1 collaterals (OR: 26.9; p<0.001). Frequently applied solutions included microcatheter switching (61.9%), and microcatheter switching combined with GUIDEZILLA (14.3%) or anchoring balloon technique (6.3%).

CONCLUSIONS

Initial microcatheter CC tracking failure was found in nearly one quarter of procedures after wire CC tracking success. Independent angiographic predictors of initial microcatheter CC tracking failure included CC 0-1 collaterals, channel entry angle <90°, and channel exit angle <90° for septal collaterals, and CC 1 collaterals for epicardial collaterals.

Bioresorbable vascular scaffolds for percutaneous treatment of chronic total coronary occlusions: a meta-analysis

BACKGROUND

BRS represent a new approach to treating coronary artery disease. Beneficial properties of BRS regarding the restoration of vasomotility after resorption make them attractive devices in CTO revascularization. However, experience in this setting is limited.

METHODS

We systematically searched Medline, Scholar, and Scopus for reports of at least 9 patients with CTO undergoing BRS implantation. Patients' and procedural characteristics were summarized. The primary outcome of interest was target lesion revascularization (TLR). Pooled estimates were calculated using a random-effects meta-analysis. The study protocol was registered in PROSPERO (CRD42017069322).

RESULTS

Thirteen reports for a total of 843 lesions with a median follow-up of 12 months (IQR 6-12) were included in the analysis. At short-term, the summary estimate rate of TLR was 2.6% (95% CI: 1 to 4%, I² = 0%, P = 0.887) while at mid to long-term it was 3.8% (95% CI: 2 to 6%, I² = 0%, P = 0.803). At long-term follow-up (≥12 months), the summary estimate rate of cardiac death was 1.1% (95% CI: 0 to 2%, I² = 0%, P = 0.887). The summary estimate rates of scaffold thrombosis and clinical restenosis were respectively 0.9% (95% CI: 0 to 2%, I² = 0%, P = 0.919) and 1.8% (95% CI: 0 to 4%, I² = 0%, P = 0.448). Finally, the summary estimate rate of target vessel revascularization was 6.6% (95% CI: 0 to 11%, I² = 0%, P = 0.04).

CONCLUSIONS

Implantation of BRS in a population with CTO is feasible, although further longer-term outcome studies are necessary.

Optimal medical therapy vs. coronary revascularization for patients presenting with chronic total occlusion: A meta-analysis of randomized controlled trials and propensity score adjusted studies

INTRODUCTION

The optimal management of patients with coronary chronic total occlusions (CTO) remains controversial. This meta-analysis aims to compare percutaneous coronary intervention of CTO (CTO-PCI) versus optimal medical therapy (OMT) in CTO patients.

METHODS

A literature search with highly specific terms was conducted using MEDLINE, EMBASE, and Web of Science to identify most relevant randomized controlled trials (RCTs) and observational studies with propensity score matching (PSM) evaluating differences in between CTO-PCI versus OMT. The primary endpoint was the incidence of major adverse cardiac events (MACEs, composite of cardiovascular death, acute coronary syndrome, and repeat PCI, re-PCI) while its single components were defined as secondary endpoints.

RESULTS

A total of eight studies was included, four RCTs and four PSMs. 3,971 patients were included in the analysis (2,050 CTO-PCI versus 1,921 OMT) with a mean follow-up of 3 years. No significant differences were found regarding overall MACE, re-PCI and AMI. Regarding CV-death, CTO-PCI was associated with a better outcome compared with OMT driven by PSMs (OR 0.52, 0.0.81, P < 0.01).

CONCLUSIONS

As compared to OMT, CTO-PCI was associated with similar MACE rate; however, CTO-PCI may be associated with reduced CV death, mainly due to PSMs effect.

Recovery of myocardial perfusion after percutaneous coronary intervention of chronic total occlusions is comparable to hemodynamically significant non-occlusive lesions

Background

The benefits of chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) are being questioned. The aim of this study was to assess the effects of CTO PCI on absolute myocardial perfusion, as compared with PCI of hemodynamically significant non‐CTO lesions.

Methods

Consecutive patients with a preserved left ventricular ejection fraction (≥50%) and a CTO or non‐CTO lesion, in whom [¹⁵O]H₂O positron emission tomography was performed prior and after successful PCI, were included. Change in quantitative (hyperemic) myocardial blood flow (MBF), coronary flow reserve (CFR) and perfusion defect size (in myocardial segments) were compared between CTOs and non‐CTO lesions.

Results

In total 92 patients with a CTO and 31 patients with a non‐CTO lesion were included. CTOs induced larger perfusion defect sizes (4.51 ± 1.69 vs. 3.23 ± 2.38 segments, P < 0.01) with lower hyperemic MBF (1.30 ± 0.37 vs. 1.58 ± 0.62 mL·min⁻¹·g⁻¹, P < 0.01) and similarly impaired CFR (1.66 ± 0.75 vs. 1.89 ± 0.77, P = 0.17) compared with non‐CTO lesions. After PCI both hyperemic MBF and CFR increased similarly between groups (P = 0.57 and 0.35) to normal ranges with higher hyperemic MBF values in non‐CTO compared with CTO (2.89 ± 0.94 vs. 2.48 ± 0.73 mL·min⁻¹·g⁻¹, P = 0.03). Perfusion defect sizes decreased similarly after CTO PCI and non‐CTO PCI (P = 0.14), leading to small residual defect sizes in both groups (1.15 ± 1.44 vs. 0.61 ± 1.45 segments, P = 0.054).

Conclusions

Myocardial perfusion findings are slightly more hampered in patients with a CTO before and after PCI. Percutaneous revascularization of CTOs, however, improves absolute myocardial perfusion similarly to PCI of hemodynamically significant non‐CTO lesions, leading to satisfying results.

Coronary chronic total occlusion intervention: utility or futility

INTRODUCTION

Despite an incidence of about 18-52% of the patients undergoing coronary angiography, chronic total occlusions (CTO) are rarely revascularised by percutaneous angioplasty (PCI). Nevertheless, current evidence suggests that successful CTO angioplasty improves symptoms, quality of life and long-term survival. During the last decade, the improvement of specific tools and techniques for these complex procedures, and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO angioplasty. Areas covered: This review focuses on the clinical benefits of CTO revascularization and on appropriate patient selection. Expert commentary: Current evidence suggests that successful CTO-PCI improves symptoms, quality of life and long-term survival. During the last years, the improvement of specific techniques for these complex procedures and the increasing experience of operators, have led to the achievement of success and complication rates almost equivalent to non-CTO lesion angioplasty.