Chronic Total Occlusions: A State-of-the-Art Review.

The percutaneous management of chronic total occlusions (CTO) is a well-established sub-specialty of Interventional Cardiology, requiring specialist equipment, training, and techniques. The heterogeneity of approaches in CTO has led to the generation of multiple algorithms to guide operators in their management. The evidence base for management of CTOs has suffered from inconsistent descriptive and quantitative terminology in defining the nature of lesions and techniques utilised, as well as seemingly contradictory data about improvement in ventricular function, symptoms of angina, and mortality from large-scale registries and randomised controlled trials. Through this review, we explore the history of CTO management and its supporting evidence in detail, with an outline of limitations of CTO-percutaneous coronary intervention and a look at the future of this growing field within cardiology.

Validation of the new PROGRESS-CTO complication risk scores in the OPEN-CTO registry.

BACKGROUND: Risk stratification before chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is important to inform procedural planning as well as patients and their families. We sought to externally validate the PROGRESS-CTO complication risk scores in the OPEN-CTO registry. METHODS: OPEN-CTO is a prospective registry of 1000 consecutive CTO PCIs performed at 12 experienced US centers using the hybrid algorithm. Endpoints of interest were in-hospital all-cause mortality, need for pericardiocentesis, acute myocardial infarction (MI), and major adverse cardiovascular events (MACE) (a composite of all-cause mortality, stroke, periprocedural MI, urgent repeat revascularization, and tamponade requiring pericardiocentesis). Model discrimination was assessed with the area under the curve (AUC) method, and calibration with the observed-versus-predicted probability method. RESULTS: Mean age was 65.4 ± 10.3 year, and 36.5% of patients had prior coronary artery bypass graft. Overall, 41 patients (4.1%) suffered MACE, 9 (0.9%) mortality, 26 (2.6%) acute MI, and 11 (1.1%) required pericardiocentesis. Technical success was achieved in 86.3%. Patients who experienced MACE had higher anatomic complexity, and more often required antegrade dissection/reentry and the retrograde approach. Increasing PROGRESS-CTO MACE scores were associated with increasing MACE rates: 0.5% (score 0-1), 2.4% (score 2), 3.7% (score 3), 4.5% (score 4), 7.8% (score 5), 13.0% (score 6-7). The AUC were as follows: MACE 0.72 (95% confidence interval [CI]: 0.66-0.78), mortality 0.79 (95% CI: 0.66-0.95), pericardiocentesis 0.71 (95% CI: 0.60-0.82), and acute MI 0.57 (95% CI: 0.49-0.66). Calibration was adequate for MACE and mortality, while the models underestimated the risk of pericardiocentesis and acute MI. CONCLUSIONS: In a large external cohort of patients treated with the hybrid algorithm by experienced CTO operators, the PROGRESS-CTO MACE, mortality, and pericardiocentesis risk scores showed good discrimination, while the acute MI score had inferior performance.

Development and validation of a prediction model for angiographic perforation during chronic total occlusion percutaneous coronary intervention: OPEN-CLEAN perforation score.

BACKGROUND: Perforation is the most frequent complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and is associated with adverse events including mortality. METHODS: Among 1,000 consecutive patients enrolled in 12 center prospective CTO PCI study (OPEN CTO), all perforations were reviewed by the angiographic core-lab. Eighty-nine patients (8.9%) with angiographic perforation were compared to 911 patients without perforation. We sought to describe the clinical and angiographic predictors of angiographic perforation during CTO PCI and develop a risk prediction model. RESULTS: Among eight clinically important candidate variables, independent risk factors for perforation included prior CABG (OR 2.0 [95% CI, 1.2-3.3], p < .01), occlusion length (OR 1.2 per 10 mm increase [95% CI, 1.1-1.3], p < .01), ejection fraction (OR 1.2 per 10% decrease [95% CI, 1.1-1.5], p < .01), age (OR 1.3 per 5 year increase [95%CI, 1.1-1.5], p < .01), and heavy calcification (OR 1.7 [95% CI, 1.0-2.7], p = .04). Three other potential candidate variables, glomerular filtration rate, proximal cap ambiguity, and target vessel, were not independently associated with perforation. The model was internally validated using bootstrapping methods. From the full model, a simplified perforation prediction score (OPEN-CLEAN score: CABG, Length [occlusion], EF < 50%, Age, CalcificatioN) was developed, which discriminated the risk of angiographic perforation well (c-statistics = 0.75) and demonstrated good calibration. CONCLUSION: This simple 5-variable prediction score may help CTO operators to risk-stratify patients for angiographic perforation using variables available prior to CTO PCI procedures.

Contemporary Evidence-Based Diagnosis and Management of Severe Coronary Artery Calcification.

Percutaneous treatment of heavily calcified coronary lesions remains a challenge for interventional cardiologists with increased risk of incomplete lesion preparation, suboptimal stent deployment, procedural complications, and a higher rate of acute and late stent failure. Adequate lesion preparation through calcium modification is crucial in optimising procedural outcomes. Several calcium modification devices and techniques exist, with rotational atherectomy the predominant treatment for severely calcified lesions. Novel technologies such as intravascular lithotripsy are now available and show promise as a less technical and highly effective approach for calcium modification. Emerging evidence also emphasises the value of detailed characterisation of calcification severity and distribution especially with intracoronary imaging for appropriate device selection and individualised treatment strategy. This review aims to provide an overview of the non-invasive and invasive evaluation of coronary calcification, discuss calcium modification techniques and propose an algorithm for the management of calcified coronary lesions.

Impact of body mass index on outcome and health status after chronic total occlusion percutaneous coronary intervention: Insights from the OPEN-CTO study.

BACKGROUND: The effect of body mass index (BMI) on the procedural outcomes and health status (HS) change after chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is largely unknown. METHODS: Thousand consecutive patients enrolled in a 12-center prospective CTO PCI study (Outcomes, Patient Health Status, and Efficiency in Chronic Total Occlusion Hybrid Procedures [OPEN-CTO]) were categorized into three groups by baseline BMI (obese ≥30, overweight 25-30, and normal 18.5-25), after excluding seven patients with BMI <18.5. Baseline and follow-up HS at 1 year were quantified using the Seattle Angina Questionnaire, Rose Dyspnea Score, and Personal Health Questionnaire-8 (PHQ-8). Hierarchical, multivariable logistic, and repeated measures linear regression models were used to assess procedural success, major adverse cardiovascular and cerebrovascular events (MACCE), and HS outcomes, as appropriate. RESULTS: The obese and overweight were 47.6% and 37.4%, respectively. While procedure time and contrast dose were similar among the groups, total radiation dose (mGy) was higher with increased BMI (3,019 ± 2,027, 2,267 ± 1,714, 1,642 ± 1,223, p < .01). Procedural success rates, as well as MACCE rates, were similar among the three groups (obese 83.1%, overweight 79.8%, normal 81.9%, p = .47 and 5.1, 8.4, and 8.7%, p = .11). These rates remained similar after adjustment for baseline characteristics. The HS improvement from baseline to 12 months after adjustment was similar in obese and overweight patients compared to normal weight patients. CONCLUSIONS: CTO PCI in obese and overweight patients can be performed with similar success and complication rates. Obese and overweight patients derive similar HS benefit from CTO PCI compared to normal weight patients.

Intermediate procedural and health status outcomes and the clinical care pathways after chronic total occlusion angioplasty: A report from the OPEN-CTO (outcomes, patient health status, and efficiency in chronic total occlusion hybrid procedures) study.

BACKGROUND: No previous reports have described the comprehensive care pathways involved in chronic total occlusion percutaneous coronary intervention (CTO PCI). METHODS: In a study of 1,000 consecutive patients undergoing CTO PCI using hybrid approach, a systematic algorithm of selecting CTO PCI strategies, the procedural characteristics, complication rates, and patient reported health status outcomes through 12 months were assessed. RESULTS: Technical success of the index CTO PCI was 86%, with 89% of patients having at least one successful CTO PCI within 12 months. A total of 13.8% underwent CTO PCI of another vessel or reattempt of index CTO PCI within 1 year. At 1 year, the unadjusted major adverse cardiac and cerebral event (MACCE) rate was lower in patients with successful index CTO PCI compared to patients with unsuccessful index CTO PCI (9.4% vs. 14.6%, p = .04). The adjusted hazard ratios of myocardial infarction and death at 12 months were numerically lower in patients with successful index CTO PCI, compared to patients with unsuccessful index CTO PCI. Patients with successful index CTO PCI reported significantly greater improvement in health status throughout 12-months compared to patients with unsuccessful index CTO PCI. CONCLUSION: CTO-PCI in the real-world often require treatment of second CTO, non-CTO PCI or repeat procedures to treat initially unsuccessful lesions. Successful CTO PCI is associated with numerically lower MACCE at 1 year and persistent symptomatic improvement compared to unsuccessful CTO PCI. Understanding the relationship between the care pathways following CTO PCI and health status benefit requires further study.

Outcomes of retrograde chronic total occlusion percutaneous coronary intervention: A report from the OPEN-CTO registry.

OBJECTIVES: We sought to assess in-hospital and long-term outcomes of retrograde compared with antegrade-only percutaneous coronary intervention for chronic total occlusion (CTO PCI). BACKGROUND: Procedural and clinical outcomes following retrograde compared with antegrade-only CTO PCI remain unknown. METHODS: Using the core-lab adjudicated OPEN-CTO registry, we compared the outcomes of retrograde to antegrade-only CTO PCI. Primary endpoints included were in-hospital major adverse cardiac and cerebrovascular events (MACCE) (all-cause death, stroke, myocardial infarction [MI], emergency cardiac surgery, or clinically significant perforation) and MACCE at 1-year (all-cause death, MI, stroke, target lesion revascularization, or target vessel reocclusion). RESULTS: Among 885 single CTO procedures from the OPEN-CTO registry, 454 were retrograde and 431 were antegrade-only. Lesion complexity was higher (J-CTO score: 2.7 vs. 1.9; p < .001) and technical success lower (82.4 vs. 94.2%; p < .001) in retrograde compared with antegrade-only procedures. All-cause death was higher in the retrograde group in-hospital (2 vs. 0%; p = .003), but not at 1-year (4.9 vs. 3.3%; p = .29). Compared with antegrade-only procedures, in-hospital MACCE rates (composite of all-cause death, stroke, MI, emergency cardiac surgery, and clinically significant perforation) were higher in the retrograde group (10.8 vs. 3.3%; p < .001) and at 1-year (19.5 vs. 13.9%; p = .03). In sensitivity analyses landmarked at discharge, there was no difference in MACCE rates at 1 year following retrograde versus antegrade-only CTO PCI. Improvements in Seattle Angina Questionnaire Quality of Life scores at 1-year were similar between the retrograde and antegrade-only groups (29.9 vs 30.4; p = .58). CONCLUSIONS: In the OPEN-CTO registry, retrograde CTO procedures were associated with higher rates of in-hospital MACCE compared with antegrade-only; however, post-discharge outcomes, including quality of life improvements, were similar between technical modalities.

Use of the Instantaneous Wave-free Ratio or Fractional Flow Reserve in PCI.

BACKGROUND: Coronary revascularization guided by fractional flow reserve (FFR) is associated with better patient outcomes after the procedure than revascularization guided by angiography alone. It is unknown whether the instantaneous wave-free ratio (iFR), an alternative measure that does not require the administration of adenosine, will offer benefits similar to those of FFR. METHODS: We randomly assigned 2492 patients with coronary artery disease, in a 1:1 ratio, to undergo either iFR-guided or FFR-guided coronary revascularization. The primary end point was the 1-year risk of major adverse cardiac events, which were a composite of death from any cause, nonfatal myocardial infarction, or unplanned revascularization. The trial was designed to show the noninferiority of iFR to FFR, with a margin of 3.4 percentage points for the difference in risk. RESULTS: At 1 year, the primary end point had occurred in 78 of 1148 patients (6.8%) in the iFR group and in 83 of 1182 patients (7.0%) in the FFR group (difference in risk, -0.2 percentage points; 95% confidence interval [CI], -2.3 to 1.8; P<0.001 for noninferiority; hazard ratio, 0.95; 95% CI, 0.68 to 1.33; P=0.78). The risk of each component of the primary end point and of death from cardiovascular or noncardiovascular causes did not differ significantly between the groups. The number of patients who had adverse procedural symptoms and clinical signs was significantly lower in the iFR group than in the FFR group (39 patients [3.1%] vs. 385 patients [30.8%], P<0.001), and the median procedural time was significantly shorter (40.5 minutes vs. 45.0 minutes, P=0.001). CONCLUSIONS: Coronary revascularization guided by iFR was noninferior to revascularization guided by FFR with respect to the risk of major adverse cardiac events at 1 year. The rate of adverse procedural signs and symptoms was lower and the procedural time was shorter with iFR than with FFR. (Funded by Philips Volcano; DEFINE-FLAIR ClinicalTrials.gov number, NCT02053038 .).

De-escalation of antianginal medications after successful chronic total occlusion percutaneous coronary intervention: Frequency and relationship with health status.

BACKGROUND: Successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can markedly reduce angina symptom burden, but many patients often remain on multiple antianginal medications (AAMs) after the procedure. It is unclear when, or if, AAMs can be de-escalated to prevent adverse effects or limit polypharmacy. We examined the association of de-escalation of AAMs after CTO PCI with long-term health status. METHODS: In a 12-center registry of consecutive CTO PCI patients, health status was assessed at 6 months after successful CTO PCI with the Seattle Angina Questionnaire and the Rose Dyspnea Scale. Among patients with technical CTO PCI success, we examined the association of AAM de-escalation with 6-month health status using multivariable models adjusting for revascularization completeness and predicted risk of post-PCI angina (using a validated risk model). We also examined predictors and variability of AAMs de-escalation. RESULTS: Of 669 patients with technical success of CTO PCI, AAMs were de-escalated in 276 (35.9%) patients at 1 month. Patients with AAM de-escalation reported similar angina and dyspnea rates at 6 months compared with those whose AAMs were reduced (any angina: 22.5% vs 20%, P = .43; any dyspnea: 51.8% vs 50.1%, P = .40). In a multivariable model adjusting for complete revascularization and predicted risk of post-PCI angina, de-escalation of AAMs at 1 month was not associated with an increased risk of angina, dyspnea, or worse health status at 6 months. CONCLUSIONS: Among patients with successful CTO PCI, de-escalation of AAMs occurred in about one-third of patients at 1 month and was not associated with worse long-term health status.

A sex stratified outcome analysis from the OPEN-CTO registry.

INTRODUCTION: Women have been under-represented in trials. Due to the dearth of information about CTO-PCI in women and discordance of previous results, sex differences in outcomes in the OPEN-CTO Trial were investigated. METHODS: OPEN-CTO is an investigator-initiated, multicenter, prospective observational registry of consecutive CTO patients undergoing PCI at 12 U.S. centers. The one-year outcomes of this trial stratified by sex were examined. Optimal propensity matching was performed to compare outcomes between sexes. Multivariate conditional logistic regression modeling for predictors of procedural success was performed. RESULTS: Women represented 19.6% of the cohort (196/1,000 patients). Women were more likely to report dyspnea as their predominant symptom. Women reported statistically worse physical limitation and poorer quality of life as compared to men. J-CTO scores were similar in males and females. Technical, procedural success and MACE rates were similar in both sexes. Contrast and radiation doses were however significantly lower in women. The SAQ- summary score, RDS, EQ-5D VAS, PHQ-8 scores were all improved to the same degree at 1 year in women as compared to men. Predictors of procedural success revealed that younger age, lower J-CTO score and absence of prior CABG were predictors of procedural success. Sex did not predict procedural success or 1-year MACE in this regression model. CONCLUSION: This real-world registry revealed that women derive the same benefit from CTO-PCI as men without additional complications and with favorable health status outcomes at 1 year. Consideration of revascularization by PCI in symptomatic women should be considered as part of the treatment when appropriate.