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

Preprocedural Planning for Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusions (CTO) are frequently encountered in clinical practice. Although the success rates and safety of CTO percutaneous coronary intervention (PCI) have significantly improved with the development of newer equipment, use of an algorithmic approach, and advancement in procedural techniques, CTO PCI has a higher rate of complication than does non-CTO PCI. Therefore, meticulous preprocedural planning before CTO PCI is paramount to improve success and reduce the risk of complications. In this report, we review multiple aspects of preprocedural CTO PCI planning, including procedural indications, efficacy, safety, diagnostic angiography, scoring tools for procedural success and risk prediction, and preprocedural use of computed tomography coronary angiography.

Evaluation of Success and Complications Scores for Chronic Total Occlusion Percutaneous Coronary Interventions: Insights from the Latin American Registry

Chronic total occlusion (CTO) percutaneous coronary intervention is a complex procedure and is associated with considerable risk of complications. Several success and complication scores have been developed; however, data regarding their external validation in other populations such as Latin America are scarce. This study aimed to evaluate the accuracy of the main predictors of success and complications in a broad cohort of procedures in the Latin American (LATAM) CTO registry. From April 2008 to December 2023, 3,706 consecutive procedures listed in the LATAM CTO registry were screened. Of these, 2,835 procedures had sufficient information to analyze the Multicenter CTO Registry in Japan (J-CTO); Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS); Ostial location, Rentrop grade, and Age (ORA); Clinical and Lesion-related Score (CL-score); and EuroCTO Score (CASTLE) success scores. The complication scores were PROGRESS (MACE, mortality, and pericardiocentesis) and Outcomes, Patient health status, and Efficiency iN Chronic Total Occlusion hybrid procedures (OPEN-CTO),OPEN-CLEAN. The J-CTO and CASTLE scores demonstrated the highest areas under the curve (AUC) of 0.718 and 0.703, respectively. The AUC value for the CL-score was 0.685, whereas the PROGRESS score had an AUC of 0.598 and the ORA AUC was 0.545. The level of agreement between scores was low; only 4% of the procedures were classified as difficult or very difficult by all scores and <1% were classified as easy by all 5 scores. Of the complication scores, PROGRESS mortality (AUC 0.651) and PROGRESS MACE (AUC 0.588) showed the best performance, identifying groups with >10% event rate. These results may improve the selection of revascularization techniques, especially for patient demographics that are historically underrepresented in CTO research.

Impact of calcium on the procedural techniques and outcomes of chronic total occlusion percutaneous coronary intervention

BACKGROUND

Coronary calcification is common and increases the difficulty of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

We examined the impact of calcium on procedural outcomes of 13,079 CTO PCIs performed in 12,799 patients at 46 US and non-US centers between 2012 and 2023.

RESULTS

Moderate or severe calcification was present in 46.6% of CTO lesions. Patients whose lesions were calcified were older and more likely to have had prior coronary artery bypass graft surgery. Calcified lesions were more complex with higher J-CTO score (3.0 ± 1.1 vs. 1.9 ± 1.2; p < 0.001) and lower technical (83.0% vs. 89.9%; p < 0.001) and procedural (81.0% vs. 89.1%; p < 0.001) success rates compared with mildly calcified or non-calcified CTO lesions. The retrograde approach was more commonly used among cases with moderate/severe calcification (40.3% vs. 23.5%; p < 0.001). Balloon angioplasty (76.6%) was the most common lesion preparation technique for calcified lesions, followed by rotational atherectomy (7.3%), laser atherectomy (3.4%) and, intravascular lithotripsy (3.4%). The incidence of major adverse cardiovascular events (MACE) was higher in cases with moderate or severe calcification (3.0% vs. 1.2%; p < 0.001), as was the incidence of perforation (6.5% vs. 3.4%; p < 0.001). On multivariable analysis, the presence of moderate/severe calcification was independently associated with lower technical success (odds ratio, OR = 0.73, 95% CI: 0.63-0.84) and higher MACE (OR = 2.33, 95% CI: 1.66-3.27).

CONCLUSIONS

Moderate/severe calcification was present in nearly half of CTO lesions, and was associated with higher utilization of the retrograde approach, lower technical and procedural success rates, and higher incidence of in-hospital MACE.

Retrograde balloon hemostasis

Despite improvements in current devices and techniques for complex chronic total occlusion (CTO) percutaneous coronary intervention (PCI), procedural complications, including coronary perforation, still occur and could be life-threatening. A patient with a history of multivessel coronary artery disease and a CTO of the right coronary artery (RCA) underwent successful retrograde crossing of an RCA CTO. After wiring the CTO body and lesion dilatation, a drug-eluting stent was implanted in the distal RCA toward the posterior descending artery. A large Ellis type III perforation occurred at the distal edge of the stent. Septal crossing with a balloon and tamponade of the perforation site through the retrograde collaterals followed, as the RCA was not suitable to accommodate easily both the covered stent and the balloon simultaneously. This case report presents a novel approach the "septal retrograde ping-pong" technique, which demonstrates successful treatment of coronary perforations by utilizing a retrograde approach through a septal collateral. This technique proves to be effective in situations where the conventional antegrade balloon or covered stent delivery methods are not feasible or unsuccessful. This innovative approach offers a promising alternative for managing challenging cases of coronary perforations, providing new insights and potential solutions for interventional cardiologists.

A Systematic Review of Periprocedural Risk Prediction Scores in Chronic Total Occlusion Percutaneous Coronary Intervention

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with high incidence of complications. We queried PubMed and the Cochrane Library (last search: October 26, 2022) for CTO PCI-specific periprocedural complication risk scores. We identified 8 CTO PCI-specific risk scores: (1) Angiographic coronary artery perforation (OPEN-CLEAN [Outcomes, Patient Health Status, and Efficiency iN (OPEN) Chronic Total Occlusion (CTO) Hybrid Procedures - CABG, Length (occlusion), EF <50%, Age, CalcificatioN] perforation, c-statistic 0.75): previous coronary artery bypass graft surgery, occlusion length 20 to 60 mm or ≥60 mm, left ventricular ejection fraction (LVEF) <50%, age 50 to 70 years or ≥70 years, heavy calcification. (2) Major adverse cardiovascular events (MACE) (PROGRESS-CTO complication, c-statistic 0.76): age >65 years, lesion length ≥23 mm, retrograde strategy, and (3) MACE (PROGRESS-CTO MACE, c-statistic 0.74): age ≥65 years, female gender, moderate/severe calcification, blunt/no stump, anterograde dissection and re-entry (ADR) or retrograde strategy. (4) All-cause mortality (PROGRESS-CTO mortality, c-statistic 0.80): age ≥65, moderate/severe calcification, LVEF ≤45%, ADR or retrograde strategy. (5) Perforation requiring pericardiocentesis (PROGRESS-CTO pericardiocentesis, c-statistic 0.78): age ≥65 years, moderate/severe calcification, female gender, ADR or retrograde strategy. (6) Acute myocardial infarction (PROGRESS-CTO acute myocardial infarction, c-statistic 0.72): previous coronary artery bypass graft surgery, atrial fibrillation, blunt/no stump. (7) Perforation requiring any treatment (PROGRESS-CTO perforation, c-statistic 0.74): age ≥65 years, moderate/severe calcification, blunt/no stump, ADR, or retrograde strategy. (8) Contrast-induced acute kidney injury (c-statistic 0.84): age ≥75, LVEF <40%, serum creatinine >1.5 mg/100 ml, serum albumin ≤30, 30<albumin≤40 or >40 g/L. There are 8 CTO PCI periprocedural risk scores that may facilitate risk assessment and procedural planning in patients who underwent CTO PCI.

Impact of lesion length on the outcomes of chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry

BACKGROUND

The impact of occlusion length on the procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

METHODS

We examined the clinical and angiographic characteristics and procedural outcomes of 10,335 CTO PCIs at 42 US and non-US centers between 2012 and 2022. The cohort was divided into two groups based on lesion length (≥20 mm vs. <20 mm).

RESULTS

Long lesions were present in 7208 (70%) patients. Comorbidities were more common in patients with long CTOs. Compared with short lesions, long lesions had higher J-CTO score (2.8 ± 1.1 vs. 1.3 ± 1; p < 0.001) and retrograde wiring was more often the initial (15.5% vs. 4.0%; p < 0.001) and successful (22.8% vs. 8.2%; p < 0.001) crossing strategy. Long lesions were more likely to require longer procedure (123 vs. 91 min; p < 0.001) and fluoroscopy (47.1 vs. 32.2 min; p < 0.001) time, larger contrast volume (218 vs. 200 mL; p < 0.001) and higher air kerma radiation dose (2.4 vs. 1.7 Gy; p < 0.001). After adjusting for potential confounders, long lesions were associated with lower technical success (odds ratio [OR]: 0.91 per 10 mm increase; 95% confidence interval [CI]: 0.88, 0.94) and higher major adverse cardiovascular events (MACE) (OR: 1.08 per 10 mm increase; 95% CI: 1.02, 1.15).

CONCLUSIONS

CTO PCI of long occlusions is independently associated with lower rates of technical success and higher rates of in-hospital MACE.

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.

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.

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.

Development and validation of a scoring system for predicting clinical coronary artery perforation during percutaneous coronary intervention of chronic total occlusions: the PROGRESS-CTO perforation score

BACKGROUND

Coronary artery perforation is a feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) and often leads to serious adverse clinical events.

AIMS

We sought to develop a risk score to predict clinical coronary artery perforation in patients undergoing CTO PCI.

METHODS

We analysed clinical and angiographic parameters from 9,618 CTO PCIs in the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO). Logistic regression prediction modelling was used to identify variables independently associated with clinical perforation, and the model was internally validated with bootstrapping. Clinical coronary artery perforation was defined as any perforation requiring treatment.

RESULTS

The incidence of clinical coronary perforation was 3.8% (n=367). Five factors were independently associated with perforation and were included in the score: patient age ≥65 years +1 point (odds ratio [OR] 1.79, 95% confidence interval [CI]: 1.37-2.33), moderate/severe calcification +1 point (OR 1.85, 95% CI: 1.41-2.42), blunt/no stump +1 point (OR 1.45, 95% CI: 1.10-1.92), use of antegrade dissection and re-entry +1 point (OR 2.43, 95% CI: 1.61-3.69), and use of the retrograde approach +2 points (OR 4.02, 95% CI: 2.95-5.46). The resulting score showed acceptable performance on receiver operating characteristic (ROC) curve (area under the curve [AUC]: 0.741, 95% CI: 0.712-0.773). The Hosmer-Lemeshow test indicated a good fit (p=0.991), and internal validation with bootstrapping demonstrated good agreement with the model with observed AUC: 0.736 (95% bias-corrected CI: 0.706-0.767).

CONCLUSIONS

The PROGRESS-CTO perforation score may be a useful tool for predicting clinical coronary perforation during CTO PCI.

Predicting Periprocedural Complications in Chronic Total Occlusion Percutaneous Coronary Intervention: The PROGRESS-CTO Complication Scores

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is associated with increased risk of periprocedural complications. Estimating the risk of complications facilitates risk-benefit assessment and procedural planning.

OBJECTIVES

This study sought to develop risk scores for in-hospital major adverse cardiovascular events (MACE), mortality, pericardiocentesis, and acute myocardial infarction (MI) in patients undergoing CTO PCI.

METHODS

The study analyzed the PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) and created risk scores for MACE, mortality, pericardiocentesis, and acute MI. Logistic regression prediction modeling was used to identify independently associated variables, and models were internally validated with bootstrapping.

RESULTS

The incidence of periprocedural complications among 10,480 CTO PCIs was as follows: MACE 215 (2.05%), mortality 47 (0.45%), pericardiocentesis 83 (1.08%), and acute MI 66 (0.63%). The final model for MACE included ≥65 years of age (1 point), moderate-severe calcification (1 point), blunt stump (1 point), antegrade dissection and re-entry (ADR) (1 point), female (2 points), and retrograde (2 points); the final model for mortality included ≥65 years of age (1 point), left ventricular ejection fraction ≤45% (1 point), moderate-severe calcification (1 point), ADR (1 point), and retrograde (1 point); the final model for pericardiocentesis included ≥65 years of age (1 point), female (1 point), moderate-severe calcification (1 point), ADR (1 point), and retrograde (2 points); the final model for acute MI included prior coronary artery bypass graft surgery (1 point), atrial fibrillation (1 point), and blunt stump (1 point). The C-statistics of the models were 0.74, 0.80, 0.78, 0.72 for MACE, mortality, pericardiocentesis, and acute MI, respectively.

CONCLUSIONS

The PROGRESS-CTO complication risk scores can facilitate estimation of the periprocedural complication risk in patients undergoing CTO PCI.