Randomized Trial Evaluating Percutaneous Coronary Intervention for the Treatment of Chronic Total Occlusion

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.

Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention of the Left Anterior Descending Artery

The left anterior descending artery (LAD) subtends a large myocardial territory. The outcomes of LAD chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study. We performed a retrospective analysis of all patients who underwent LAD CTO PCI at a high-volume single center. Outcomes included in-hospital and long-term major adverse cardiovascular events (MACEs) and changes in left ventricular ejection fraction (LVEF). We performed a subgroup analysis of patients with ischemic cardiomyopathy, defined as an LVEF of 40% or less. From December 2014 to February 2021, 237 patients underwent LAD CTO PCI. The technical success rate was 97.4%, and the in-hospital MACE rate was 5.4%, A landmark analysis after hospital discharge showed an overall survival of 92% and 85% MACE-free survival at 2 years. There was no difference in overall survival or MACE-free survival between those who had ischemic cardiomyopathy versus those who did not. In patients with ischemic cardiomyopathy, LAD CTO PCI was associated with significant improvement in LVEF (10.9% at 9 months), which was further pronounced when these patients had a proximal LAD CTO and were on optimal medical therapy (14% at 6 months). In a single high-volume center, LAD CTO PCI was associated with 92% overall survival at 2 years, with no difference in survival between patients with or without ischemic cardiomyopathy. LAD CTO PCI was associated with an absolute 10% increase in LVEF at 9 months in patients with ischemic cardiomyopathy.

International randomized trial on the effect of revascularization or optimal medical therapy of chronic total coronary occlusions with myocardial ischemia - ISCHEMIA-CTO trial - rationale and design

BACKGROUND

Chronic total occlusions (CTO) are frequent among patients with coronary artery disease. Revascularization with percutaneous coronary intervention (PCI) is safe and feasible in experienced hands. However, randomized data are needed to demonstrate symptomatic as well as prognostic effect of CTO-PCI compared to optimal medical therapy alone.

METHODS

This trial aims to evaluate the effect of CTO PCI in patients with a CTO lesion and target vessel diameter ≥ 2.5 mm, and myocardial ischemia in the relevant territory. First, all patients are subjected to optimal medical therapy (OMT) for at least for 3 months and non-CTO lesions are managed according to guidelines. Subsequently, prior to randomization myocardial ischemia and quality of life (Seattle Questionnaire (SAQ)) is assessed. Patients are divided into two cohorts based on their SAQ score and randomized to either OMT alone or OMT and CTO-PCI. Cohort A is defined as Low- or asymptomatic patients with a quality-of-life score > 60 and/or CCS class < 2, and more than 10 % ischemia in the left ventricle (LV). Cohort B is symptomatic patients with a quality-of-life score < 60 or CCS class angina > 1 and at least ischemia in 5% of the LV. The primary end-point in cohort A is a composite of major adverse cardiac and cerebral events, hospitalization for heart failure and malignant ventricular arrhythmias. The primary endpoint in cohort B is difference in quality of life 6 months after randomization.

IMPLICATIONS

This trial is designed to investigate if CTO-PCI improves QoL and MACCE. Both positive and negative outcome of the trial will affect future guidelines and recommendations on how to treat patients with CTO.

Validation of the OPEN-CLEAN Chronic Total Occlusion Percutaneous Coronary Intervention Perforation Score in a Multicenter Registry

Coronary artery perforation is one of the most common and feared complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We evaluated the utility of the recently presented OPEN-CLEAN (Coronary artery bypass graft, Length of occlusion, Ejection fraction, Age, calcificatioN) perforation score in an independent multicenter CTO PCI dataset. Of the 2,270 patients who underwent CTO PCI at 7 centers, 150 (6.6%) suffered coronary artery perforation. Patients with perforations were older (69 ± 10 vs 65 ± 10, p <0.001), more likely to be women (89% vs 82%, p = 0.010), more likely to have history of previous coronary artery bypass graft (38% vs 20%, p <0.001), and unfavorable angiographic characteristics such as blunt stump (64% vs 42%, p <0.001), proximal cap ambiguity (51% vs 33%, p <0.001), and moderate-severe calcification (57% vs 43%, p = 0.001). Technical success was lower in patients with perforations (69% vs 85%, p <0.001). The area under the receiver operating characteristic curve of the OPEN-CLEAN perforation risk model was 0.74 (95% confidence interval 0.68 to 0.79), with good calibration (Hosmer-Lemeshow p = 0.72). We found that the CTO PCI perforation risk increased with higher OPEN-CLEAN scores: 3.5% (score 0 to 1), 3.1% (score 2), 5.3% (score 3), 7.1% (score 4), 11.5% (score 5), 19.8% (score 6 to 7). In conclusion, given its good performance and ease of preprocedural calculation, the OPEN-CLEAN perforation score appears to be useful for quantifying the perforation risk for patients who underwent CTO PCI.

In-Hospital Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions in Heart failure patients

In-hospital outcomes of chronic total occlusion Percutaneous Coronary Interventions (CTO PCI) in heart failure patients has not been evaluated on a national base and was the focus of this investigation. We used the Nationwide Inpatient Sample database from 2008 to 2014 to identify adults with single vessel CTO PCI for stable ischemic heart disease (SIHD). Patients were divided into 3 groups: patients without heart failure, heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF). Clinical characteristics and in-hospital outcomes were studied using relevant statistics. Multiple logistic regression models were performed to assess in-hospital mortality, acute renal failure, and the use of mechanical support devices. Of 112,061 inpatients with SIHD from 2008 to 2014 undergoing CTO PCI, 21,185 (19%) had HFrEF and 3309 (3%) had HFpEF. Compared to patients without heart failure, HFrEF and HFpEF patients were older (mean age 69.2 vs 66.3, 70.3 vs 66.3 respectively, P < 0.001), had more comorbidities and higher acute in-hospital complications. HFrEF patients had higher adjusted in-hospital mortality [AOR 1.73, 95% CI (1.21-2.48)], acute renal failure [AOR 2.68, 95% CI (2.34-3.06)], and need for mechanical support [AOR 2.76, 95% CI (2.17-3.51)]. Compared to patients without heart failure, HFpEF patients had similar mortality and need for mechanical support, but higher incidence of acute renal failure. Older age was significantly associated with increased in-hospital mortality. chronic total occlusion PCI in patients with heart failure is associated with higher in-hospital morbidity and mortality and warrants further investigation to optimize health care delivery.

Chronic Total Occlusion Interventions in Patients with Reduced Ejection Fraction

PURPOSE OF THE REVIEW

The goal of this paper is to review the current evidence surrounding CTO PCI in patients with low EF, the most high-risk population to treat. We also present pertinent case examples and offer practical tips to increase success and lower complications when performing CTO PCI in patients with low EF.

RECENT FINDINGS

In a prospective randomized control study, greater improvement in angina frequency and quality of life, assessed by the Seattle Angina Questionnaire, was achieved by CTO PCI compared to optimal medical therapy. Furthermore, after successful CTO PCI, improvements in health status were similar in patients with both low and normal EF. CTO PCI can not only ameliorate symptoms of angina in patients with low EF but may also potentially improve EF in carefully selected populations. However, information regarding treatment of this high-risk population is lacking and large-scale studies targeting patients with severely reduced EF remain necessary.

Long term clinical outcome after success re-attempt percutaneous coronary intervention of chronic total occlusion

BACKGROUND

To evaluate the long-term outcome after re-attempt CTO-PCI.

METHODS

This is a retrospective cohort study that included 113 re-attempt CTO-PCI patients who were consecutively registered from January 2019 to December 2020 at Beijing Anzhen Hospital's Center of Coronary Artery Disease. All patients were divided into two groups based on procedural success or failure. The primary endpoint was major adverse cardiac events (MACE), a composite of all-cause mortality, myocardial infarction and target vessel revascularization (TVR). The secondary endpoint was angina after PCI.

RESULTS

Overall, the successful re-attempt CTO-PCI was archived in 77 patients, the failed CTO-PCI was performed in 36 patients. After a median follow-up of 21.7 months (interquartile range: 10.9-26.0), the incidence of the primary outcome was significantly lower in the success group [14.2% vs. 38.9%, adjusted hazard ratio (HR) 0.351, 95% CI 0.134-0.917, P = 0.033], mainly driven by the reduction of TVR (9.1% vs. 30.6%, adjusted HR 0.238, 95% CI: 0.078-0.72, P = 0.011). Furthermore, patients who had successful re-attempt CTO-PCI had a lower risk of angina after PCI (27.3% vs.61.1%, adjusted HR 0.357, 95% CI 0.167-0.76, P = 0.008). The risk factors of TVR in the patients with successful re-attempt CTO-PCI were stent length > 100 mm (adjusted HR 21.805, 95% CI 1.765-269.368, P = 0.016) and J-CTO score > 3(adjusted HR: 9.733, 95% CI:1.533-61.797, P = 0.016).

CONCLUSIONS

For the patients with previous CTO-PCI failure, a successful re-attempt CTO-PCI was associated with significantly lower MACE, which was primarily driven by a lower TVR rate. More complex CTO lesions and longer stents were the independent predictors of TVR after successful CTO-PCI.

Collateral presence and extent do not predict myocardial viability and ischemia in chronic total occlusions: A stress-CMR study

BACKGROUND

Well-developed collaterals are assumed as a marker of viability and ischemia in chronic total occlusions (CTO). We aim to correlate viability and ischemia with collateral presence and extent in CTO patients by cardiac magnetic resonance (CMR).

METHODS

Multicentre study of 150 CTO patients undergoing stress-CMR, including adenosine if normal systolic function, high-dose-dobutamine for patients with akinetic/>2 hypokinetic segments and EF ≥35%, otherwise low-dose-dobutamine (LDD); all patients underwent late gadolinium enhancement (LGE) imaging. Viability was defined as mean LGE transmurality ≤50% for adenosine, as functional improvement for dobutamine-stress-test, ischemia as ≥1.5 segments with perfusion defects outside the scar zone.

RESULTS

Rentrop 3/CC 2 defined well-developed (WD, n = 74) vs poorly-developed collaterals (PD, n = 76). Viability was equally prevalent in WD vs PD: normo-functional myocardium with ≤50% LGE in 52% vs 58% segments, p = 0.76, functional improvement by LDD in 48% vs 52%, p = 0.12. Segments with none, 1-25%,26-50%,51-75% LGE showed viability by LDD in 90%,84%,81%,61% of cases, whilst in 12% if 76-100% LGE (p < 0.01). There was no difference in WD vs PD for ischemia presence (74% vs 75%, p = 0.99) and extent (2.7 vs 2.8 segments, p = 0.77).

CONCLUSIONS

In a large cohort of CTO patients, presence and extent of collaterals did not predict viability and ischemia by stress-CMR. Scar extent up to 75% LGE was still associated with viability, whereas ischemia was undetectable in 25% of patients, suggesting that the assessment of CTO patients with CMR would lead to a more comprehensive evaluation of viability and ischemia to guide revascularization.

Long-term follow-up of patients with chronic total coronary artery occlusion previously randomized to treatment with optimal drug therapy or percutaneous revascularization of chronic total occlusion (COMET-CTO)

Background

The COMET-CTO trial was a randomized prospective study that assessed long-term follow-up in patients with chronic total occlusion (CTO) in coronary arteries treated with percutaneous coronary intervention (PCI) or with optimal medical therapy (OMT). During the 9-month follow-up, the incidence of major adverse cardiac events (MACE) did not differ between the two groups; no death or myocardial infarction (MI) was observed. There was a significant difference in quality of life (QoL), assessed by the Seattle Angina Questionnaire (SAQ), in favor of the PCI group. Here we report long-term follow-up results (56 ± 12 months).

Methods

Between October 2015 and May 2017, a total of 100 patients with CTO were randomized into two groups of 50 patients: PCI CTO or OMT group. The primary endpoint of the current study was the incidence of MACE defined as cardiac death, MI, and revascularization [PCI or coronary artery bypass graft (CABG)]. As the secondary exploratory outcome, we analyzed all the cause-mortality rate.

Results

Out of 100 randomized patients, 92 were available for long-term follow-up (44 in the PCI group and 48 in the OMT group). The incidence of MACE did not differ significantly between the two groups (p = 0.363). Individual components of MACE were distributed, respectively: cardiac death (OMT vs. PCI group, 6 vs. 3, p = 0.489), MI (OMT vs. PCI group, 1 vs. 0, p = 1), and revascularization (PCI: OMT vs. PCI group, 2 vs. 2, p = 1; CABG: OMT vs. PCI group, 1 vs. 1, p = 1). There was no significant difference between the two groups regarding the individual component of MACE. Six patients died from non-cardiac causes [five deaths were reported in the OMT group and one death in the PCI group (p = 0.206)]. Kaplan-Meier survival curves for MACE did not differ significantly between the study groups (log-rank 0.804, p = 0.370). Regarding the secondary exploratory outcome, a total of 15 patients died at 56 ± 12 months (11 in the OMT and 4 in the PCI group) (p = 0.093). The Kaplan-Meier survival curves for all-cause mortality rates did not differ significantly between the two groups (log rank 3.404, p = 0.065). There were no statistically significant differences between OMT and PCI groups in all five SAQ domains. There was a significant improvement in three SAQ domains in the PCI group: PL (p < 0.001), AF (p = 0.007), and QoL (p = 0.001).

Conclusion

After 56 ± 12 months of follow-up, the incidence of MACE, as well as QoL measured by SAQ, did not differ significantly between the PCI and OMT groups.

External validation of the PROGRESS-CTO perforation risk score: Individual patient data pooled analysis of three registries

BACKGROUND

Coronary artery perforation is one of the most feared and common complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

To assess the usefulness of the recently developed PROGRESS-CTO (NCT02061436) perforation risk score in independent cohorts. Individual patient-level data pooled analysis of three registries was performed.

RESULTS

Of the 4566 patients who underwent CTO PCI at 25 centers, 196 (4.2%) had coronary artery perforation. Patients with perforations were older (69 ± 10 vs. 65 ± 10, p < 0.001), more likely to be women (19% vs. 13%, p = 0.009), more likely to have a history of prior coronary artery bypass graft (34% vs. 20%, p < 0.001), and unfavorable angiographic characteristics such as blunt stump (62% vs. 48%, p < 0.001), proximal cap ambiguity (52% vs. 34%, p < 0.001), and moderate-severe calcification (60% vs. 49%, p = 0.002). Technical success was lower in patients with perforations (73% vs. 88%, p < 0.001). The area under the receiver operating characteristic curve of the PROGRESS-CTO perforation risk model was 0.76 (95% confidence interval [CI], 0.72-0.79), with good calibration (Hosmer-Lemeshow p = 0.97). We found that the CTO PCI perforation risk increased with higher PROGRESS-CTO perforation scores: 0.3% (score 0), 2.3% (score 1), 3.1% (score 2), 5.5% (score 3), 7.5% (score 4), 14.6% (score 5).

CONCLUSION

Given the good discriminative performance, calibration, and the ease of calculation, the PROGRESS-CTO perforation score may facilitate assessment of the risk of perforation in patients undergoing CTO PCI.

The challenges of a randomised placebo-controlled trial of CTO PCI vs. placebo with optimal medical therapy: The ORBITA-CTO pilot study design and protocol

Background

Percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) has been performed for the improvement of symptoms and quality of life in patients with stable angina. The ORBITA study demonstrated the role of the placebo effect in contemporary PCI in non-CTO chronic coronary syndromes. However, the benefit of CTO PCI beyond that of a placebo has not been demonstrated.

Aims

The ORBITA-CTO pilot study will be a double-blind, placebo-controlled study of CTO PCI randomising patients who have: (1) been accepted by a CTO operator for PCI; (2) experienced symptoms due to a CTO; (3) evidence of ischaemia; (4) evidence of viability within the CTO territory; and (5) a J-CTO score ≤3.

Methods

Patients will undergo medication optimisation that will ensure they are on at least a minimum amount of anti-anginals and complete questionnaires. Patients will record their symptoms on an app daily throughout the study. Patients will undergo randomisation procedures, including an overnight stay, and be discharged the following day. All anti-anginals will be stopped after randomisation and re-initiated on a patient-led basis during the 6-month follow-up period. At follow-up, patients will undergo repeat questionnaires and unblinding, with a further 2-week unblinded follow-up.

Results

The co-primary outcomes are feasibility (blinding) in this cohort and angina symptom score using an ordinal clinical outcome scale for angina. Secondary outcomes include changes in quality-of-life measures, Seattle Angina Questionnaire (SAQ), peak VO2, and anaerobic threshold on the cardiopulmonary exercise test.

Conclusion

The feasibility of a placebo-controlled CTO PCI study will lead to future studies assessing efficacy. The impact of CTO PCI on angina measured using a novel daily symptom app may provide improved fidelity in assessing symptoms in patients with CTO's.

Long-term outcomes of less drug-eluting stents by the use of drug-coated balloons in de novo coronary chronic total occlusion intervention: A multicenter observational study

Background

Data on drug-coated balloons (DCB) for de novo coronary chronic total occlusion (CTO) are limited. We aimed to investigate the long-term outcomes of substitution of drug-eluting stents (DES) by DCB.

Methods

We compared the outcomes of less DES strategy (DCB alone or combined with DES) and DES-only strategy in treating de novo coronary CTO in this prospective, observational, multicenter study. The primary endpoints were major adverse cardiovascular events (MACE), target vessel revascularization, myocardial infarction, and death during 3-year follow-up. The secondary endpoints were late lumen loss (LLL) and restenosis until 1-year after operation.

Results

Of the 591 eligible patients consecutively enrolled between January 2015 and December 2019, 281 (290 lesions) were treated with DCB (DCB-only or combined with DES) and 310 (319 lesions) with DES only. In the DCB group, 147 (50.7%) lesions were treated using DCB-only, and the bailout stenting rate was relatively low (3.1%). The average stent length per lesion in the DCB group was significantly shorter compared with the DES-only group (21.5 ± 25.5 mm vs. 54.5 ± 26.0 mm, p < 0.001). A total of 112 patients in the DCB group and 71 patients in the DES-only group (38.6% vs. 22.3%, p < 0.001) completed angiographic follow-up until 1-year, and LLL was much less in the DCB group (-0.08 ± 0.65 mm vs. 0.35 ± 0.62 mm, p < 0.001). There were no significant differences in restenosis occurrence between the two groups (20.5% vs. 19.7%, p > 0.999). The Kaplan-Meier estimates of MACE at 3-year (11.8% vs. 12.0%, log-rank p = 0.688) was similar between the groups.

Conclusion

Percutaneous coronary intervention with DCB is a potential "stent-less" therapy for de novo CTO lesions with satisfactory long-term clinical results compared to the DES-only approach.

Percutaneous coronary intervention improves quality of life of patients with chronic total occlusion and low estimated glomerular filtration rate

Background

A low estimated glomerular filtration rate (eGFR <90 mL/min/1.73 m²) is widely recognized as a risk factor for major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). However, the impact of successful CTO-PCI on quality of life (QOL) of patients with low eGFR remains unknown.

Objectives

The aim of this prospective study was to assess the QOL of CTO patients with low eGFR after successful PCI.

Methods

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled and subdivided into four groups: eGFR ≥90 mL/min/1.73 m² (n = 410), 90 > eGFR ≥ 60 mL/min/1.73 m² (n = 482), 60 > eGFR ≥ 30 mL/min/1.73 m² (n = 161), and eGFR <30 mL/min/1.73 m² (n = 23). The primary outcomes included QOL, as assessed with the European Quality of Life-5 Dimensions (EQ-5D) questionnaire, and symptoms, as assessed with the Rose Dyspnea Scale (RDS) and Seattle Angina Questionnaire (SAQ), at 1 month and 1 year after successful PCI.

Results

With the decline of eGFR, CTO patients were more likely to present with comorbidities of hypertension, diabetes, hyperuricemia, and previous stroke, in addition to lower hemoglobin levels and left ventricular ejection fraction (p < 0.05). Low eGFR was associated with greater incidences of in-hospital pericardiocentesis, major bleeding, acute renal failure, and subcutaneous hematoma, but not in-hospital MACE (p < 0.05). Symptoms of dyspnea and angina were alleviated in all CTO patients with eGFR ≥30 mL/min/1.73 m² at 1 month and 1 year after successful CTO-PCI, but only at 1 month for those with eGFR <30 mL/min/1.73 m² (p < 0.01). Importantly, QOL was markedly improved at 1 month and 1 year after successful PCI (p < 0.01), notably at a similar degree between patients with low eGFR and those with normal eGFR (p > 0.05).

Conclusion

Successful PCI effectively improved symptoms and QOL of CTO patients with low eGFR.

Patient Selection and Clinical Indication for Chronic Total Occlusion Revascularization-A Workflow Focusing on Non-Invasive Cardiac Imaging

Percutaneous coronary intervention of chronic total occlusion (CTO PCI) is a challenging procedure with high complication rates and, as not yet fully understood long-term clinical benefits. Ischemic symptom relief in patients with high ischemic burden is to date the only established clinical indication to undergo CTO PCI, supported by randomized controlled trials. In this context, current guidelines suggest attempting CTO PCI only in non-invasively assessed viable CTO correspondent myocardial territories, with large ischemic areas. Hence, besides a comprehensive coronary angiography lesion evaluation, the information derived from non-invasive cardiac imaging techniques is crucial to selecting candidates who may benefit from the revascularization of the occluded vessel. Currently, there are no clear recommendations for a non-invasive myocardial evaluation or choice of imaging modality pre-CTO PCI. Therefore, selecting among available options is left to the physician's discretion. As CTO PCI is strongly recommended to be carried out explicitly in experienced centers, full access to non-invasive imaging for risk-benefit assessment as well as a systematic institutional evaluation process has to be encouraged. In this framework, we opted to review the current myocardial imaging tools and their use for indicating a CTO PCI. Furthermore, based on our experience, we propose a cost-effective systematic approach for myocardial assessment to help guide clinical decision-making for patients presenting with chronic total occlusions.

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.

Benefits of successful percutaneous coronary intervention in chronic total occlusion patients with diabetes

BACKGROUND

Diabetes was commonly seen in chronic total occlusion (CTO) patients but data regarding the impact of successful percutaneous coronary intervention (PCI) on clinical outcome of CTO patients with diabetes was controversial. And importantly, no studies have compared quality of life (QOL) after CTO-PCI in patients with and without diabetes.

METHODS

Consecutive patients undergoing elective CTO-PCI were prospectively enrolled from Apr. 2018 to May 2021. Patients were subdivided into 2 groups: Diabetes and No Diabetes. Detailed baseline characteristics, assessment of symptoms and QOL, angiographic and procedural details, in-hospital complications, and 1 month and 1 year follow-up data were collected. These data were analyzed accordingly for risk predictors of clinical outcome in patients who have diabetes and received successful CTO-PCI.

RESULTS

A total of 1076 patients underwent CTO-PCI attempts. Diabetes was present in 374 (34.76%) patients, who had more hypertension, previous PCI and stroke. Regarding the coronary lesions, diabetic patients suffered more LCX lesion, multivessel disease, number of lesions per patient, blunt stump, calcification and higher J-CTO score (p < 0.05). In-hospital major adverse cardiac event (MACE) (4.13% vs. 5.35%; p = 0.362) was similar in the two groups. At 1 month and 1 year follow-up after successful CTO-PCI, the incidence of MACE and all-cause mortality were also similar in the two groups (p > 0.05). Number of lesions per patient was an independent risk factor of MACE and all-cause mortality (p < 0.001) 1 year after successful CTO-PCI. Symptom and QOL were markedly improved regardless of diabetes both at 1 month and 1 year follow-up, and importantly, patients with diabetes showed similar degrees of improvement to those without diabetes (P > 0.05).

CONCLUSIONS

Successful CTO-PCI could represent an effective strategy improving clinical outcome, symptoms and QOL in CTO patients with diabetes.

Mid-Term Outcome of Ventricular Arrhythmias Catheter Ablation in Patients with Chronic Coronary Total Occlusion Compared to Ischemic and Non-Ischemic Patients

Chronic coronary total occlusions (CTO) are considered an emerging predictor of ventricular arrhythmias (VAs), but currently there are few data on arrhythmic outcomes in patients affected by CTO undergoing radiofrequency catheter ablation of VAs. This study sought to evaluate the impact of unrevascularized CTO on the recurrence of VAs after catheter ablation. This was a single-center retrospective study enrolling 120 patients between 2015 and 2020. All patients were admitted for ventricular tachycardia (VT) or high premature ventricular contractions burden (>25% detected by Holter ECG), without evidence of acute coronary syndrome; they underwent coronary angiography, electrophysiology (EP) study, and three-dimensional electroanatomic mapping (3D-EAM) followed by VAs ablation. Twenty-eight patients (23%) of 120 patients showed CTO at coronary angiography. At baseline, the CTO group presented with higher prevalence of hypertension, chronic renal disease, systolic ventricular dysfunction, secondary prevention ICD implantation, and higher rate of LAVA by 3D-EAM compared with the non-CTO group. At a median follow-up of 15 months (range 1−96 months) after catheter ablation, the only independent predictor of VAs recurrence was the presence of moderate to severe left ventricular (LV) dysfunction. Therefore, the presence of CTO does not predict VAs recurrence after catheter ablation, which is instead predicted by LV dysfunction.

Why and How Should We Treat Chronic Total Occlusion? Evolution of State-of-the-Art Methods and Future Directions

Chronic total occlusions are considered the most complex coronary lesion in interventional cardiology. The absence of visible lumen on angiography obscures the vessel course and makes vessel wiring unlikely with conventional techniques. Often a source of severe ischemia, chronic occlusions are also markers of advanced atherosclerosis that brings other complex features including lesion length, bifurcations, calcification, adverse vessel remodelling, distal disease, and anatomic distortion from previous bypass grafting. Often advanced atherosclerosis is associated with patient characteristics like left ventricular dysfunction, previous coronary bypass surgery, or multivessel disease that increase procedural demands and hazards. To accommodate these challenges new techniques and dedicated technologies have been developed. When applied to appropriate patients, these advances have improved procedural success, safety, and outcomes. Our aim is to provide the general cardiologist with an overview of these advances that can serve as a basis for counselling patients considered for revascularization.

Recanalisation of coronary chronic total occlusions

Percutaneous treatment of coronary chronic total occlusions (CTO) has advanced greatly since its advent in the late 1970s through the development of dedicated wires and microcatheters, the improved skills of highly experienced operators and the adoption of new sophisticated strategies to guide procedural planning. The contemporary procedural success rate is 80-90% with a reduction in complications. Although there has been no improvement in prognosis in randomised trials to date, they, and other controlled registries of thousands of patients, confirm the pivotal role of CTO recanalisation in the treatment of angina and dyspnoea and an improvement in quality of life. Despite this evidence, CTO recanalisation is grossly underutilised. This review reports a detailed overview of the history, indications and treatment strategies for CTO recanalisation and hopes to increase interest among new, and especially young, operators in this demanding, rapidly evolving field of interventional cardiology.

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.

Predicting the Success Rate of Elective Percutaneous Coronary Intervention for Prior Failed Chronic Total Occlusion: a Novel Scoring System

To investigate a scoring system for predicting the risk of successful percutaneous coronary intervention (PCI) after prior failed chronic total occlusion (CTO). Patients with previously attempted CTO-PCI were enrolled in our study retrospectively from January 2016 to December 2019. All clinical and procedural data were collected and analyzed. Univariate and multivariate logistic regression was performed to investigate the predictors of technical success. A total of 194 patients/CTO lesions were studied. The multivariate logistic regression showed that occlusion length < 20 mm (odds ratio (OR) = 2.94, score = 1), non-calcification (OR = 2.93, score = 1), adequate distal landing zone (OR = 4.46, score = 1), Rentrop grade ≥ 2 (OR = 5.98, score = 1), and retrograde approach as the initial strategy (OR = 10.28, score = 2) were predictors of the success of re-attempt PCI. The technical success rate for scores from 0 to ≥ 4 were 0%, 17.9%, 46.2%, 77.8%, and 93.3% respectively. Our scoring system can be used to predict the success rate of re-attempt CTO-PCI.

Comparative Analysis of Patient Characteristics in Chronic Total Occlusion Revascularization Studies: Trials vs Real-World Registries

BACKGROUND

The few randomized controlled trials (RCTs) on chronic total occlusion (CTO) percutaneous coronary intervention (PCI) are subject to selection bias.

OBJECTIVES

The purpose of this study was to evaluate the differences between real-world CTO patients and those enrolled in RCTs.

METHODS

This study performed a meta-analysis of national and dedicated CTO PCI registries and compared patient characteristics and outcomes with those of RCTs that randomized patients to CTO PCI versus medical therapy. Given the large sample size differences between RCTs and registries, the study focused on the absolute numbers and their clinical significance. The study considered a 5% relative difference between groups to be potentially clinically relevant.

RESULTS

From 2012 to 2022, 6 RCTs compared CTO PCI versus medical therapy (n = 1,047) and were compared with 15 registries (5 national and 10 dedicated CTO PCI registries). Compared with registry patients, RCT patients had fewer comorbidities, including diabetes, hypertension, previous myocardial infarction, and prior coronary artery bypass graft surgery. RCT patients had shorter CTO length (29.6 ± 19.7 mm vs 32.6 ± 23.0 mm, a relative difference of 9.2%) and lower Japan-Chronic Total Occlusion Score scores (2.0 ± 1.1 vs 2.3 ± 1.2, a relative difference of 13%) compared with those enrolled in dedicated CTO registries. Procedural success was similar between RCTs (84.5%) and dedicated CTO registries (81.4%) but was lower in national registries (63.9%).

CONCLUSIONS

There is a paucity of randomized data on CTO PCI outcomes (6 RCTs, n = 1,047). These patients have lower risk profiles and less complex CTOs than those in real-world registries. Current evidence from RCTs may not be representative of real-world patients and should be interpreted within its limitation.

Temporal Trends in Complex Percutaneous Coronary Interventions

Background

Accumulated experience combined with technological advancements in percutaneous coronary interventions (PCI) over the past four decades, has led to a gradual increase in PCI utilization and complexity. We aimed to investigate the temporal trends in PCI complexity and the outcomes of complex PCI (C-PCI) in our institution.

Methods

We analyzed 20,301 consecutive PCI procedures performed over a 12-year period. C-PCI was defined as a procedure involving at least one of the following: Chronic total occlusion (CTO), left main (LM), bifurcation or saphenous vein graft (SVG) PCI. Four periods of 3-year time intervals were defined (2008–10, 2011–2013, 2014–2016, 2017–2019), and temporal trends in the rate and outcomes of C-PCI within these intervals were studied. Endpoints included mortality and major adverse cardiac events [MACE: death, acute myocardial infarction (MI), and target vessel revascularization (TVR)] at 1 year.

Results

A total of 5,647 (27.8%) C-PCI procedures were performed. The rate of C-PCI has risen significantly since 2,017 (31.2%, p < 0.01), driven mainly by bifurcation and LM interventions (p < 0.01). At 1-year, rates of death, acute MI, TVR and MACE, were all significantly higher in the C-PCI group (8.8 vs. 5.1%, 5.6 vs. 4.5%, 5.5 vs. 4.0%, 17.2 vs. 12.2%, p < 0.001 for all, respectively), as compared to the non-complex group. C-PCI preformed in the latter half of the study period (2014–2019) were associated with improved 1-year TVR (4.4% and 4.8% vs. 6.7% and 7.1%, p = 0.01, respectively) and MACE (13.8% and 13.5% vs. 17.3% and 18.2%, p = 0.001, respectively) rates compared to the earlier period (2007–2013). Death rate had not significantly declined with time.

Conclusion

In the current cohort, we have detected a temporal increase in PCI complexity coupled with improved 1-year clinical outcomes in C-PCI.

Contemporary Management of Refractory Angina

Refractory angina (RA) is defined as chest pain caused by coronary ischemia in patients on maximal medical therapy and is not amenable to revascularization despite advanced coronary artery disease (CAD). The long-term prognosis has improved with optimal medical therapy including risk factor modification. Still, patients are left with major impairment in quality of life and have high resource utilization with limited treatment options. We review the novel invasive and noninvasive therapies under investigation for RA.

Revascularization in stable coronary artery disease

Management of stable coronary artery disease (CAD) centers on medication to prevent myocardial infarction and death. Many anti-anginal medications also have benefit for reducing symptoms, and have been proven to be effective against placebo control. Before effective preventive medications were available, patients with stable CAD often underwent revascularization with coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI), on the plausible assumption that these procedures would prevent adverse events and reduce symptoms. However, recent randomized controlled trials have cast doubt on these assumptions.Considering results from the recent ISCHEMIA trial, we discuss the evidence base that underpins revascularization for stable CAD in contemporary practice. We also focus on patient groups at high risk of myocardial infarction and death, for whom revascularization is often recommended. We outline the areas of uncertainty, unanswered research questions, and key areas of potential miscommunication in doctor-patient consultations.

Cost-Effectiveness in Patients Undergoing Revascularization of Chronic Total Occluded Coronary Arteries—A Cohort Study

Background

Revascularization of patients with chronic total occluded coronary arteries (CTO) is recommended if they have symptoms despite medical treatment. The cost-effectiveness of treatment with percutaneous coronary intervention (PCI) was investigated in this cohort study.

Materials and Methods

The study was designed as a cohort study enrolling all patients undergoing PCI for a CTO in the Central Region of Denmark and recorded in the EUROCTO database. Major adverse cardio- and cerebrovascular events (MACCE) and admissions for cardiac symptoms were collected in the Western Denmark Heart Registry and through medical Journal Audits. Exposure was defined as successful revascularization of all CTO lesions compared with having one or more remaining CTOs after PCI attempt(s). Cost-effectiveness was evaluated as the net benefit (NB) at the patient level 3 years after treatment and through cost-effectiveness planes. The cost was defined as the cumulative cost of the index procedure and admissions due to MACCE and cardiac symptoms. Effectiveness was defined as the difference in MACCE for the primary analysis and the difference in death and symptomatic admissions for the secondary.

Results

Between 2009 and 2019, 441 patients with ≥ 3 years of follow-up were treated with PCI for at least one CTO lesion (342 in the successful arm and 99 in the unsuccessful arm). The technical success rate was 85.4%. In total, 155 MACCE and 184 symptomatic admissions occurred in the follow-up period. The mean total cost was EUR 11.719 (11.034; 12.406) in the successful group vs. EUR 13.565 (11.899; 15,231) (p = 0.02) in the unsuccessful group. Net-benefit was EUR 1.846 (64; 3,627) after successful revascularization for MACCE. The adjusted analysis found an NB of EUR 1,481 (–118; 3,079). Bootstrap estimates showed cost-effectiveness planes in favor of successful revascularization.

Conclusion

Patients fully revascularized for all CTO lesions had a more cost-efficient treatment. However, results need confirmation in a randomized controlled trial due to the risk of residual confounding after adjustment.

Nicorandil Improves Left Ventricular Myocardial Strain in Patients With Coronary Chronic Total Occlusion

Background

Nicorandil is recommended as a second-line treatment for stable angina; however, randomized-controlled trials to evaluate the benefit of nicorandil for patients with chronic total occlusion (CTO) are lacking.

Objective

To determine whether nicorandil can improve left ventricular (LV) myocardial strain in patients with CTO.

Methods

Patients with CTO were included and randomized to the nicorandil group (n = 31) and the control group (n = 30). Nicorandil was given orally at 15 mg/day for 3 months in the nicorandil group. Three-dimensional speckle-tracking echocardiography and the Seattle Angina Questionnaire (SAQ) survey were performed at baseline and at 3 months. The primary study endpoint was the LV global area strain (GAS) at 3 months.

Results

The nicorandil and the control groups were well-matched at baseline, including the mean GAS and SAQ scores. At 3 months, GAS in the nicorandil group was significantly higher than that in the control group (−23.7 ± 6.3% vs. −20.3 ± 5.6%, respectively; p = 0.033). There were no significant differences in LV global longitudinal strain, global circumferential strain, global radial strain, LV ejection fraction, LV end-diastolic volume, and LV end-systolic volume at 3 months between the two groups. At 3 months, the SAQ scores for angina stability, angina frequency, and treatment satisfaction in the nicorandil group were significantly higher than those in the control group.

Conclusion

Nicorandil treatment can improve GAS and angina symptoms in patients with CTO.

Clinical Trial Registration

www.ClinicalTrials.gov, identifier: NCT05087797.

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.

Clinical Outcomes of Drug-Coated Balloon Treatment After Successful Revascularization of de novo Chronic Total Occlusions

Background

The safety and efficacy of drug-coated balloon (DCB) treatment for de novo coronary chronic total occlusion (CTO) remain uncertain. The aim of this study was to evaluate the outcomes of DCB only treatment for de novo CTO.

Methods

In this retrospective study, 101 vessels with de novo CTO lesions dilated by balloon angioplasty with thrombolysis in myocardial infarction flow grade 3 were included. Among them, 93 vessels successfully treated with DCB only treatment were analyzed. The study endpoint was major adverse cardiac events (MACE) at 2 years, a composite of cardiac death, non-fatal myocardial infarction (MI), target vessel revascularization (TVR), and target vessel thrombosis. The secondary endpoint was late lumen loss (LLL) on follow-up coronary angiography.

Results

All 84 patients were followed up clinically, and 67 vessels underwent scheduled coronary angiography after 6 months. There were no procedural complications, and three vessels required bailout-stenting. The median follow-up was 720 days (interquartile range [IQR]; 406–1,268 days). MACE occurred in 8.3% of the patients after 1 year, including cardiac death (1.2%), TVR (7.1%), and no non-fatal MI and target vessel thrombosis. Two years after treatment, MACE occurred in 16.7% of the patients, including cardiac death (2.4%), non-fatal MI (3.6%), TVR (13.1%), and no target vessel thrombosis. The mean LLL was 0.03 ± 0.53 mm. Binary restenosis occurred in 14.9% of the treated vessels, and 3.0% of the vessels had late re-occlusion on follow-up coronary angiography.

Conclusions

If the result of revascularization using balloon angioplasty is good, the clinical outcomes of DCB only treatment of de novo CTOs at the 2-year follow-up are encouraging, with a low rate of hard endpoints and acceptable MACE rates (Clinical Trial Registration Information; Impact of Drug-coated Balloon Treatment in de novo Coronary Lesion; NCT04619277).

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.

Factors associated with all-cause mortality in patients with coronary artery chronic total occlusions undergoing revascularization (percutaneous coronary intervention or surgery) or medical treatment

Aim    Chronic total occlusion of a coronary artery (CTO) is a predictor of early and late cardiovascular mortality and poor cardiovascular outcomes in patients with coronary artery disease. The purpose of this study was to identify predictors of all-cause mortality in CTO patients that underwent invasive treatment.Material and methods    Patients between 2012 and 2018 with CTO in at least one vessel, as demonstrated by coronary angiography, were included retrospectively in the study. The patients were divided into two groups, an intervention group (percutaneous and surgical revascularization) and a medical group.Results    A total of 543 patients were studied, 152 females (28%) and 391 males (72%). The median follow-up period was 49 (26-72) mos. A total of 186 (34.2%) patients in the medical group and 357 (65.8%) patients in the invasive therapy group were followed. The 5-yr death rate was observed in 50 (26.9%) patients in the medical group and 53 (14.8%) patients in the intervention group, and it was found to be statistically higher in the medical group (p=0.001). In multivariable analysis, heart failure (odds ratio (OR): 1.92, 95% CI: 1.18-3.14; p=0.01), higher glucose levels (OR: 1.05, 95% CI: 1,02-1.08; p=0.04), lower albumin levels (OR: 0.49, 95% Cl: 0.32-0.72; p=0.001), SYNTAX score (OR: 1.03, 95% CI: 1.01-1.05; p=0.001), and CTO (≥2 occluded artery) (OR: 0.42, 95% CI: 0.22-0.72; p=0.01) were independent factors for all-cause mortality.Conclusion    In comparison to the revascularized group, there was an increase in mortality among CTO patients treated medically. Heart failure, SYNTAX score, albumin, glucose, and CTO (≥2 occluded arteries) were independent risk factors for all-cause mortality.

Quantification of strain analysis and late gadolinium enhancement in coronary chronic total occlusion: a cardiovascular magnetic resonance imaging follow-up study

Background

The present study aimed to investigate the benefits of percutaneous coronary intervention (PCI) in patients with chronic total occlusions (CTOs) by using cardiac magnetic resonance imaging (CMR) feature tracking.

Methods

Fifty-five CTOs with successful CTO-PCI underwent CMR at baseline and 12 months. Feature tracking was applied to measure left ventricle strain index in CTOs with decreased and preserved left ventricular ejection fraction (LVEF). CTOs were also divided into two groups according to the infarct size of 10% or combined with multi-vessel disease. We also measured these parameters in 40 healthy subjects.

Results

Three quarters of CTOs showed preserved ejection fraction and no enlargement of left ventricle at baseline, but the global strains were lower than the controls (all P<0.01). In the entire CTO population, left ventricular ejection fraction did not show significant improvement in the 1-year follow-up (59.8%±11.3% vs. 62.0%±8.6%, P=0.08). However, global strains improved over time, and peak global radial strain and circumferential strain showed significant treatment effect of CTO-PCI in the entire CTO population (31.1%±9.9% vs. 34.3%±8.7%, P<0.01; -17.9±3.6 vs. -19.2±3.1, P<0.01), and the subgroup with decreased LVEF, infarct size less than 10%, or multi-vessel disease, but not with the 1-vessel disease. In the LAD and LCX CTO territory, radial and circumferential strain showed treatment effect of CTO-PCI on the recovery of strain parameters (P<0.01 for both). In the RCA CTO territory, circumferential and longitudinal strain showed treatment effect of CTO-PCI on the recovery of strain parameters (P<0.05 for both).

Conclusions

In this single center study, global radial strain and circumferential strain showed treatment effect of successful CTO-PCI at 1-year follow-up in CTOs with the decreased LVEF, infarct size less than 10%, or multi-vessel disease, and the regional strain also showed a similar trend. However, the benefit of CTO-PCI on the strain recovery was not shown in patients with 1-vessel disease. Therefore, whether patients with CTO benefit from PCI still needs further verification.

Coronary Artery Bypass Grafting and Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion and Multivessel Disease

BACKGROUND

Percutaneous coronary intervention (PCI) has been used increasingly as an alternative means of revascularization for patients with chronic total occlusion and multivessel disease. We investigated 5-year clinical outcomes following coronary artery bypass grafting (CABG) and PCI in patients with chronic total occlusion and multivessel disease.

METHODS

In this single-center, retrospective cohort study, 4324 consecutive patients with ≥1 chronic total occlusion and multivessel disease were treated with either CABG (n=2264) or PCI (n=2060) between 2010 and 2013. The primary outcome was 5-year composite of death, myocardial infarction, or stroke. An inverse-probability-of-treatment weighting method was used adjusting for both patient and lesion characteristics.

RESULTS

The unadjusted 5-year composite outcomes were similar between CABG group and PCI group (12.1% [258/2264] versus 11.4% [218/2060]; P=0.52). After adjustment for baseline variables, PCI was associated with significantly higher risk of composite outcomes (adjusted hazard ratio: 1.21 [95% CI, 1.02-1.44]; P=0.03). The inferiority of PCI in 5-year composite outcome was significant in patients with CABG recommendation according to SYNTAX (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery) score II (adjusted hazard ratio: 1.55 [95% CI, 1.14-2.09]; P=0.005) but not evident in patients with PCI or PCI/CABG equipoise recommendation according to SYNTAX score II (adjusted hazard ratio: 0.94 [95% CI, 0.75-1.17]; P=0.56). A similar risk of 5-year composite outcomes was observed between CABG and PCI with residual SYNTAX score ≤8.

CONCLUSIONS

In this single-center retrospective study among patients with chronic total occlusion and multivessel disease, PCI was associated with higher risk of 5-year composite death, myocardial infarction, or stroke.

Chronic total occlusion revascularization: A complex piece to "complete" the puzzle

Treatment of coronary chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) has rapidly increased during the past decades. Different strategies and approach were developed in the recent past years leading to an increase in CTO-PCI procedural success. The goal to achieve an extended revascularization with a high rate of completeness is now supported by strong scientific evidences and consequently, has led to an exponential increase in the number of CTO-PCI procedures, even if are still underutilized. It has been widely demonstrated that complete coronary revascularization, achieved by either coronary artery bypass graft or PCI, is associated with prognostic improvement, in terms of increased survival and reduction of major adverse cardiovascular events. The application of “contemporary” strategies aimed to obtain a state-of-the-art revascularization by PCI allows to achieve long-term clinical benefit, even in high-risk patients or complex coronary anatomy with CTO. The increasing success of CTO-PCI, allowing a complete or reasonable incomplete coronary revascularization, is enabling to overcome the last great challenge of interventional cardiology, adding a “complex” piece to “complete” the puzzle.

Contemporary Issues in Chronic Total Occlusion Percutaneous Coronary Intervention

Remarkable progress has been achieved in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in recent years, with refinement of the indications and technical aspects of the procedure, imaging, and complication management. Randomized controlled trials and rigorous prospective registries have provided high-quality data on the benefits and risks of CTO PCI. Global collaboration has led to an agreement on nomenclature, indications, endpoint definition, and principles of clinical trial design that have been distilled in global consensus documents such as the CTO Academic Research Consortium. Increased use of preprocedural coronary computed tomography angiography and intraprocedural intravascular imaging, as well as development of novel techniques and structured CTO crossing and complication management algorithms, allow a systematic, stepwise approach to this difficult lesion subset. This state-of-the-art review provides a comprehensive discussion about the most recent developments in the indications, preprocedural planning, technical aspects, complication management, and future directions of CTO PCI.

The retrograde technique for recanalization of chronically occluded coronary arteries: Case series report

Introduction. Chronic total occlusion (CTO) of the coronary artery still represents one of the most challenging lesion subsets in the field of interventional cardiology. Considering the complexity and increased risk posed by the retrograde approach, it is most often performed after a failed antegrade approach. Case report. We present a series of cases describing the retrograde approach as a special technique for treating CTO of the coronary artery. All cases had some special characteristics that are part of a dedicated portfolio in every catheterization lab today. In our series of cases, all three percutaneous coronary interventions (PCI) with a different strategies of the retrograde approach and supported with rotational atherectomy or intravascular ultrasound finished with successful recanalization of CTO. Conclusion. In cases where there is the presence of ?interventional? collaterals, as well as when the antegrade approach is very difficult, the retrograde approach can increase the success rate of procedures. The retrograde approach requires a long learning curve as well as very skilled and experienced operators who are able to per-form the procedure independently.

A comparison of long-term clinical outcomes between percutaneous coronary intervention (PCI) and medical therapy in patients with chronic total occlusion in noninfarct-related artery after PCI of acute myocardial infarction

BACKGROUND

Chronic total occlusion (CTO) in a noninfarct-related artery (IRA) is one of the risk factors for mortality after acute myocardial infarction (AMI). However, there are limited data comparing the long-term outcomes of patients undergoing percutaneous coronary intervention (PCI) with patients having medical therapy (MT) in CTO lesion after AMI PCI.

METHODS

We retrospectively enrolled 330 patients (successful CTO PCI in 166 patients, failed CTO PCI in 32 patients, MT in 132 patients) with non-IRA CTO from a total of 4372 patients who underwent PCI after AMI in our center. Propensity score matching (PSM) was used to adjust for baseline differences.

RESULTS

The primary analysis is based on the intention-to-treat population. During a median follow-up period of 946 days, patients in the PCI group (n = 198) had significantly higher cardiac death-free survival (96.6% vs. 82.8%, p = .004) compared with patients in MT group (n = 132). However, no significant difference in the occurrence of cardiac death was observed after PSM. The analysis based on the per-protocol population demonstrated significantly higher cardiac death-free survival in the successful CTO PCI group (n = 166) compared with the occluded CTO group (n = 164) both before and after PSM. In subgroup analysis, successful CTO PCI was associated with less cardiac death in patients over 65 years old, with LVEF < 50%, left anterior descending (LAD) IRA, and non-LAD CTO lesion compared with occluded CTO group.

CONCLUSIONS

Patients undergoing successful revascularization of non-IRA CTO after AMI might have a better long-term prognosis. Moreover, patients with LVEF < 50% may benefit from successful non-IRA CTO PCI after AMI.