Validation of the coronary artery specific chronic total occlusion percutaneous coronary intervention angiographic difficulty scores in the PROGRESS-CTO registry.

BACKGROUND: The J-CTO investigators recently developed angiographic difficulty scores for each of the three major coronary arteries in patients undergoing first-attempt chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in de novo occlusions. METHODS: We examined the performance of the individual J-CTO scores in a large multicenter registry. RESULTS: The CTO lesion location was as follows: right coronary artery (RCA) 3,805 (54%), left anterior descending artery (LAD) 2,303 (33%), and left circumflex (LCX) 935 (13%). Patients in the PROGRESS-CTO registry were younger, more likely to be female, and had higher J-CTO scores compared with the J-CTO registry. Increasing difficulty scores were associated with lower technical success in the PROGRESS-CTO registry (score 0: 94.4 % - score ≥3: 82.6% for the RCA difficulty score; score 0: 96.4% - score ≥3: 86.1 for the LAD difficulty score; and score 0: 95.4% - score ≥3: 81.2% for the LCX difficulty score). The C-statistic of the coronary artery specific J-CTO scores in the PROGRESS-CTO registry were: LAD 0.69 (95% confidence intervals [CI], 0.64-0.73), LCX 0.63 (95% CI, 0.57-0.69), and RCA 0.61 (95-% CI, 0.58-0.64) with good calibration (Hosmer-Lemeshow p-value >0.05 for all). The AUC of the classic J-CTO score for LAD lesions was similar with the LAD J-CTO score (p-for-difference = 0.26), but worse for LCX (p-for-difference = 0.04) and RCA lesions (p-for-difference = 0.04). CONCLUSION: In the PROGRESS-CTO registry, the coronary artery specific J-CTO scores did not improve prediction of the technical success of CTO-PCI compared with the classic J-CTO score.

Chronic total occlusion percutaneous coronary intervention of anomalous coronary arteries: insights from the PROGRESS CTO registry.

BACKGROUND: There is limited information about the frequency and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in anomalous coronary arteries (ACA). METHODS: We examined the clinical and angiographic characteristics and procedural outcomes of CTO PCI in ACA among 14,173 patients who underwent 14,470 CTO PCIs at 46 US and non-US centers between 2012 and 2023. RESULTS: Of 14,470 CTO PCIs, 36 (0.24%) were CTO PCIs in an ACA. ACA patients had similar baseline characteristics as those without an ACA. The type of ACA in which the CTO lesion was found were as follows: anomalous origin of the right coronary artery (ARCA) (17, 48.5%), anomalous origin of left circumflex coronary artery (9, 25.7%), left anterior descending artery and left circumflex artery with separate origins (4, 11.4%), anomalous origin of the left anterior descending artery (2, 5.7%), dual left anterior descending artery (2, 5.7%) and woven coronary artery 1 (2.8%). The Japan CTO score was similar between both groups (2.17 ± 1.32 vs 2.38 ± 1.26, p = 0.30). The target CTO in ACA patients was more likely to have moderate/severe tortuosity (44% vs 28%, p = 0.035), required more often use of retrograde approach (27% vs 12%, p = 0.028), and was associated with longer procedure (142.5 min vs 112.00 min [74.0, 164.0], p = 0.028) and fluoroscopy (56 min [40, 79 ml] vs 42 min [25, 67], p = 0.014) time and higher contrast volume (260 ml [190, 450] vs 200 ml [150, 300], p = 0.004) but had similar procedural (91.4% vs 85.6%, p = 0.46) and technical (91.4% vs 87.0%, p = 0.59) success. No major adverse cardiac events (MACE) were seen in ACA patients (0% [0] vs 1.9% [281] in non-ACA patients, p = 1.00). Two coronary perforations were reported in ACA CTO PCI (p = 0.7 vs. non-ACA CTO PCI). CONCLUSIONS: CTO PCI of ACA comprise 0.24% of all CTO PCIs performed in the PROGRESS CTO registry and was associated with higher procedural complexity but similar technical and procedural success rates and similar MACE compared with non-ACA CTO PCI.

A comparison of procedure-related adverse events between two right ventricular leadless pacemakers.

INTRODUCTION: The Medtronic Micra VR and Abbott AVEIR VR are the leadless pacemakers (LPM) currently available in the United States (US). Micra VR employs fixation tines and the AVEIR VR uses an active fixation helix. Micra VR requires fixation before electrical measurements are obtained, while R-waves may be mapped by AVEIR VR without fixation. Little comparative data is available for these LPMs. Accordingly, we compared the incidences of procedure-related major adverse clinical events (MACE) and device problems in the US for Micra VR and AVEIR VR during 2022-2024. METHODS: We searched the FDA's Manufacturer and User Facility Device Experience (MAUDE) database for US reports of MACE and device problems that were filed from April 2022 to December 2023 for AVEIR VR, and from June 2022 to April 2024 for Micra VR. Totals for US-registered LPM implants were obtained from the manufacturers' product performance reports. RESULTS: During the study period, 5990 AVEIR VR and 10 940 Micra VR implants were registered in the US. We found 305 MAUDE reports for AVEIR VR (5.1%), versus 541 MAUDE reports for Micra VR (4.9%) (p = .702). The incidence of MACE was 0.72% (43/5990) for AVEIR VR versus 0.59% (65/10 940) for Micra VR, (p = .387). The incidences of procedure-related death, cardiac perforation. cardiac arrest, emergency pericardial drainage or reparative surgery were similar for both LPMs (p > .05). Micra VR had more unacceptable thresholds requiring LPM replacement compared to AVEIR VR (95;0.9% vs. 24;0.4%; p = .001). AVEIR VR had a statistically higher incidence of device dislodgement during (32) and after (21) implant compared to Micra VR (53 (0.9%) vs. 46 (0.4%), p < .001). CONCLUSIONS: Micra VR and AVEIR VR have similar procedural safety profiles, including the incidences of death and perforation. However, device problems differed significantly, possibly related to their design differences. Compared to Micra VR, AVEIR VR appears to have an advantageous threshold measurement capability but is more prone to device dislodgement.

Intravascular Lithotripsy versus Rotational Atherectomy in Coronary Chronic Total Occlusions: Analysis from the PROGRESS-CTO registry.

BACKGROUND: There is limited comparative data on the use of plaque modification devices during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We compared intravascular lithotripsy (IVL) with rotational atherectomy (RA) for lesion preparation in patients who underwent CTO PCI across 50 US and non-US centers from 2019 to 2024. RESULTS: Among 15,690 patients who underwent CTO PCI during the study period, 436 (2.78%) underwent IVL and 381 (2.45%) RA. Patients treated with IVL had more comorbidities and more complex CTO lesions. Antegrade wiring was the most commonly used initial and successful crossing strategy for lesions treated with both IVL and RA, although the retrograde approach was more frequently employed in IVL cases. Procedure and fluoroscopy times, as well as air kerma radiation doses and contrast volumes, were higher in patients treated with RA compared with IVL. There were no significant differences between the groups in technical success (97.2% vs. 95.3%, p=0.20), procedural success (94.7% vs. 91.8%, p=0.14), and in-hospital major adverse cardiac events (MACE) (3.0 % vs. 4.2%, p=0.47). However, coronary perforations were more frequent in patients undergoing RA (9.5% vs. 3.2%, p<0.001). Multivariable logistic regression analysis revealed that IVL compared with RA was not independently associated with technical success, procedural success, or in-hospital MACE. CONCLUSIONS: In patients undergoing CTO PCI, IVL is associated with similar in-hospital MACE, technical success, and procedural success, but lower incidence of coronary perforation, compared with RA.

Impact of Diabetes Mellitus on Bifurcation Percutaneous Coronary Intervention: Insights from the Prospective Global Registry for the Study of Bifurcation Lesion Interventions Registry.

The impact of diabetes mellitus (DM) on the outcomes of bifurcation percutaneous coronary intervention (PCI) has received limited study. We compared the procedural characteristics and outcomes of patients with and without DM in 1,302 bifurcation PCIs (1,147 patients) performed at 5 centers between 2013 and 2024. The prevalence of DM was 33.8% (n = 388). Patients with diabetes were younger and had more cardiovascular risk factors and greater angiographic complexity, including more main vessel calcification and more frequent stenoses in the left main, proximal left anterior descending, and right coronary artery. There was no difference in technical (95.5% vs 94.9%, p = 0.613) or procedural success (90.2% vs 91.3%, p = 0.540); provisional stenting was used less frequently in patients with diabetes (64.5% vs 71.1%, p = 0.015). Patients with diabetes had higher rates of repeat in-hospital PCI and acute kidney injury. Other in-hospital outcomes were similar after adjusting for confounders. During a median follow-up of 1,095 days, diabetes was independently associated with greater incidence of major adverse cardiovascular events (hazard ratio [HR] 2.04, 95% confidence intervals [CI] 1.52 to 2.72, p <0.001), myocardial infarction (HR 1.94, 95% CI 1.05 to 3.25, p = 0.033), death (HR 2.26, 95% CI 1.46 to 3.51, p <0.001), and target (HR 1.6, 95% CI 1.01 to 2.66, p = 0.045) and nontarget (HR 2.00, CI 1.06 to 3.78, p = 0.032) vessel revascularization. Patients with DM who underwent bifurcation PCI had greater risk of in-hospital repeat-PCI and major adverse cardiac events during follow-up than did those without diabetes.

External validation of the JR-CTO score in retrograde chronic total occlusion intervention: from the PROGRESS-CTO registry.

In complex chronic total occlusion (CTO) percutaneous coronary interventions (PCI), a retrograde crossing strategy is often necessary. Recently, the Japanese retrograde (JR) CTO score was developed using a simple 4-item tool. This score showed a good performance in predicting guidewire crossing failure in patients undergoing primary retrograde CTO PCI. We evaluated the JR-CTO score's performance in patients treated at 44 centers between 2013 and 2024 as part of the Prospective Global Registry for the Study of CTO Intervention (PROGRESS-CTO). In an independent cohort, although the JR-CTO score showed an association with crossing and technical failure, its predictive ability for both outcomes was modest.

Guide catheter extension use in chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS CTO registry.

There are limited data on the use of guide catheter extensions (GCE) during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We examined the frequency and temporal trends of GCE use in a large multicenter CTO-PCI registry and compared the clinical and angiographic characteristics and outcomes of cases with vs without GCE use. A GCE was used in 4106 of 14 521 CTO PCIs (28%) with increasing frequency from 18.8% in 2012 to 29.9% in 2023. The most used GCE size was 6 French (Fr) (45%), followed by 7 Fr (34%), and 8 Fr (21%). CTOs that required GCE use were more likely to have unfavorable lesion characteristics such as moderate-to-severe calcification (59% vs 40%, P < .0001), moderate-to-severe tortuosity (35% vs 28%, P < .0001), proximal cap ambiguity (39% vs 33%, P < .0001), and had higher J-CTO scores (2.78 ± 1.15 vs 2.20 ± 1.27, P < .0001). Advanced techniques like the retrograde approach (44% vs 24%, P < .0001) and antegrade dissection and re-entry (28% vs 17%, P < .0001) were more likely to be used in GCE cases. Technical success (86.6% vs 86.8%, P = .816) was similar between the 2 groups. However, major adverse cardiovascular events (MACE) (3.8% vs 2.4%, P < .0001) and procedural complications (11.2% vs 8.7%, P < .0001) were more frequent in the GCE group. In summary, GCE use in CTO PCI significantly increased between 2012 and 2023. Cases that required GCEs were more complex and had similar technical success, but higher incidence of MACE compared with cases that did not require GCEs.

Peripheral artery disease in chronic total occlusion percutaneous coronary intervention.

Background: The impact of peripheral artery disease (PAD) on the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is not well studied. Methods: We analyzed the association of PAD with CTO-PCI outcomes using data from the PROGRESS-CTO registry of procedures performed at 47 centers between 2012 and 2023. Results: The prevalence of PAD among 12 961 patients who underwent CTO PCI during the study period was 13.9% (1802). PAD patients were older, more likely to be current smokers, and had higher rates of dyslipidemia, diabetes, cerebrovascular disease, hypertension, prior myocardial infarction, PCI, and coronary artery bypass graft surgery. Their PROGRESS-CTO (1.35 vs 1.22; P < .001) and J-CTO (2.63 vs 2.33; P < .001) scores were higher, lesion length was longer, and angiographic characteristics were more complex. Their access site was more likely to be bifemoral (33.6% vs 30.9%; P = .024) compared with patients with no PAD. Technical (82.9% vs 87.7%; P < .001) and procedural (80.5% vs 86.6%; P < .001) success rates were lower in patients with PAD, while the incidence of major adverse cardiovascular events (MACE) was higher (3.1% vs 1.8%; P < .001), with higher mortality (0.8% vs 0.4%; P = .034), acute myocardial infarction rate (0.9% vs 0.4%; P = .010), and perforations rate (6.6% vs 4.5%; P < .001). In multivariable analysis, PAD was associated with higher MACE (odds ratio [OR]: 1.53; 95% CI, 1.01-2.26; P = .038) and lower technical success (OR: 0.82; 95% CI, 0.69-0.99; P = .039). Conclusions: PAD patients undergoing CTO PCI have higher comorbidity burden, more complex CTOs, higher MACE, and lower technical success.

Predicting Successful Chronic Total Occlusion Crossing With Primary Antegrade Wiring Using Machine Learning.

BACKGROUND: There is limited data on predicting successful chronic total occlusion crossing using primary antegrade wiring (AW). OBJECTIVES: The aim of this study was to develop and validate a machine learning (ML) prognostic model for successful chronic total occlusion crossing using primary AW. METHODS: We used data from 12,136 primary AW cases performed between 2012 and 2023 at 48 centers in the PROGRESS CTO registry (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; NCT02061436) to develop 5 ML models. Hyperparameter tuning was performed for the model with the best performance, and the SHAP (SHapley Additive exPlanations) explainer was implemented to estimate feature importance. RESULTS: Primary AW was successful in 6,965 cases (57.4%). Extreme gradient boosting was the best performing ML model with an average area under the receiver-operating characteristic curve of 0.775 (± 0.010). After hyperparameter tuning, the average area under the receiver-operating characteristic curve of the extreme gradient boosting model was 0.782 in the training set and 0.780 in the testing set. Among the factors examined, occlusion length had the most significant impact on predicting successful primary AW crossing followed by blunt/no stump, presence of interventional collaterals, vessel diameter, and proximal cap ambiguity. In contrast, aorto-ostial lesion location had the least impact on the outcome. A web-based application for predicting successful primary AW wiring crossing is available online (PROGRESS-CTO website) (https://www.progresscto.org/predict-aw-success). CONCLUSIONS: We developed an ML model with 14 features and high predictive capacity for successful primary AW in chronic total occlusion percutaneous coronary intervention.

Geographic diversity in chronic total occlusion percutaneous coronary intervention: insights from the PROGRESS-CTO registry.

BACKGROUND: There is variability in clinical and lesion characteristics as well as techniques in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed patient and lesion characteristics, techniques, and outcomes in 11 503 CTO-PCI procedures performed in North America (NA) and in the combined regions of Europe, Asia, and Africa from 2017 to 2023 as documented in the PROGRESS-CTO registry. RESULTS: Eight thousand four hundred seventy-nine (74%) procedures were performed in NA. Compared with non-NA patients, NA patients were older, with higher body mass index and higher prevalence of diabetes, hypertension, dyslipidemia, family history of coronary artery disease, prior history of PCI, coronary artery bypass graft surgery and heart failure, cerebrovascular disease, and peripheral arterial disease. Their CTOs were more complex, with higher J-CTO (2.56 ± 1.22 vs 1.81 ± 1.24; P less than .001) and PROGRESS-CTO (1.29 ± 1.01 vs 1.07 ± 0.95; P less than .001) scores, longer length, and higher prevalence of proximal cap ambiguity, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Retrograde (31.0% vs 22.1%; P less than .001) and antegrade dissection and re-entry (ADR) (21.2% vs 9.2%; P less than .001) were more commonly used in NA centers, along with intravascular ultrasound (69.0% vs 10.1%; P less than .001). Procedure and fluoroscopy times were longer in NA, while contrast volume and radiation dose were lower. Technical (86.7% vs 86.8%; P > .90) and procedural (85.4% vs 85.8%; P = .70) success and in-hospital major adverse cardiovascular events (MACE) (1.9% vs 1.7%; P = .40) were similar in NA and non-NA centers. CONCLUSIONS: Compared with non-NA patients, NA patients undergoing CTO PCI have more comorbidities, higher CTO lesion complexity, are more likely to undergo treatment with retrograde and ADR, and have similar technical success and MACE.

Ranolazine in chronic total occlusion percutaneous coronary intervention.

Ranolazine is an anti-anginal medication given to patients with chronic angina and persistent symptoms despite medical therapy. We examined 11 491 chronic total occlusion (CTO) percutaneous coronary interventions (PCI) that were performed at 41 US and non-US centers between 2012 and 2023 in the PROGRESS-CTO Registry. Patients on ranolazine at baseline had more comorbidities, more complex lesions, lower procedural and technical success (based on univariable but not multivariable analysis), and higher incidence of major adverse cardiac events (MACE) (on both univariable and multivariable analysis).

Resident worklife and wellness through the late phase of the pandemic: a mixed methods national survey study.

BACKGROUND: System contributors to resident burnout and well-being have been under-studied. We sought to determine factors associated with resident burnout and identify at risk groups. METHODS: We performed a US national survey between July 15 2022 and April 21, 2023 of residents in 36 specialties in 14 institutions, using the validated Mini ReZ survey with three 5 item subscales: 1) supportive workplace, 2) work pace/electronic medical record (EMR) stress, and 3) residency-specific factors (sleep, peer support, recognition by program, interruptions and staff relationships). Multilevel regressions and thematic analysis of 497 comments determined factors related to burnout. RESULTS: Of 1118 respondents (approximate median response rate 32%), 48% were female, 57% White, 21% Asian, 6% LatinX and 4% Black, with 25% PGY 1 s, 25% PGY 2 s, and 22% PGY 3 s. Programs included internal medicine (15.1%) and family medicine (11.3%) among 36 specialties. Burnout (found in 42%) was higher in females (51% vs 30% in males, p = 0.001) and PGY 2's (48% vs 35% in PGY-1 s, p = 0.029). Challenges included chaotic environments (41%) and sleep impairment (32%); favorable aspects included teamwork (94%), peer support (93%), staff support (87%) and program recognition (68%). Worklife subscales were consistently lower in females while PGY-2's reported the least supportive work environments. Worklife challenges relating to burnout included sleep impairment (adjusted Odds Ratio (aOR) 2.82 (95% CIs 1.94, 4.19), absolute risk difference (ARD) in burnout 15.9%), poor work control (aOR 2.25 (1.42, 3.58), ARD 12.2%) and chaos (aOR 1.73 (1.22, 2.47), ARD 7.9%); program recognition was related to lower burnout (aOR 0.520 (0.356, 0.760), ARD 9.3%). These variables explained 55% of burnout variance. Qualitative data confirmed sleep impairment, lack of schedule control, excess EMR and patient volume as stressors. CONCLUSIONS: These data provide a nomenclature and systematic method for addressing well-being during residency. Work conditions for females and PGY 2's may merit attention first.

Retrograde chronic total occlusion percutaneous coronary intervention via ipsilateral collaterals.

BACKGROUND: There is limited data on retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI) via ipsilateral epicardial collaterals (IEC). AIMS: To compare the clinical and angiographic characteristics, and outcomes of retrograde CTO PCI via IEC versus other collaterals in a large multicenter registry. METHODS: Observational cohort study from the Prospective Global registry for the study of Chronic Total Occlusion Intervention (PROGRESS-CTO). RESULTS: Of 4466 retrograde cases performed between 2012 and 2023, crossing through IEC was attempted in 191 (4.3%) cases with 50% wiring success. The most common target vessel in the IEC group was the left circumflex (50%), in comparison to other retrograde cases, where the right coronary artery was most common (70%). The Japanese CTO score was similar between the two groups (3.13 ± 1.23 vs. 3.06 ± 1.06, p = 0.456); however, the IEC group had a higher Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) score (1.95 ± 1.02 vs. 1.27 ± 0.92, p < 0.0001). The most used IEC guidewire was the SUOH 03 (39%), and the most frequently used microcatheter was the Caravel (43%). Dual injection was less common in IEC cases (66% vs. 89%, p < 0.0001). Technical (76% vs. 79%, p = 0.317) and procedural success rates (74% vs. 79%, p = 0.281) were not different between the two groups. However, IEC cases had a higher procedural complications rate (25.8% vs. 16.4%, p = 0.0008), including perforations (17.3% vs. 9.0%, p = 0.0001), pericardiocentesis (3.1% vs. 1.2%, p = 0.018), and dissection/thrombus of the donor vessel (3.7% vs. 1.2%, p = 0.002). CONCLUSION: The use of IEC for retrograde CTO PCI was associated with similar technical and procedural success rates when compared with other retrograde cases, but higher incidence of periprocedural complications.

Interventional cardiologists' perspectives and knowledge towards artificial intelligence.

BACKGROUND: Artificial intelligence (AI) is increasingly utilized in interventional cardiology (IC) and holds the potential to revolutionize the field. METHODS: We conducted a global, web-based, anonymous survey of IC fellows and attendings to assess the knowledge and perceptions of interventional cardiologists regarding AI use in IC. RESULTS: A total of 521 interventional cardiologists participated in the survey. The median age range of participants was 36 to 45 years, most (51.5%) practice in the United States, and 7.5% were women. Most (84.7%) could explain well or somehow knew what AI is about, and 63.7% were optimistic/very optimistic about AI in IC. However, 73.5% believed that physicians know too little about AI to use it on patients and most (46.1%) agreed that training will be necessary. Only 22.1% were currently implementing AI in their personal clinical practice, while 60.6% estimated implementation of AI in their practice during the next 5 years. Most agreed that AI will increase diagnostic efficiency, diagnostic accuracy, treatment selection, and healthcare expenditure, and decrease medical errors. The most tried AI-powered tools were image analysis (57.3%), ECG analysis (61.7%), and AI-powered algorithms (45.9%). Interventional cardiologists practicing in academic hospitals were more likely to have AI tools currently implemented in their clinical practice and to use them, women had a higher likelihood of expressing concerns regarding AI, and younger interventional cardiologists were more optimistic about AI integration in IC. CONCLUSIONS: Our survey suggests a positive attitude of interventional cardiologists regarding AI implementation in the field of IC.

Validation of the BCIS CHIP Score in chronic total occlusion percutaneous coronary intervention.

BACKGROUND: The complex high-risk indicated percutaneous coronary intervention (CHIP) score is a tool developed using the British Cardiovascular Intervention Society (BCIS) database to define CHIP cases and predict in-hospital major adverse cardiac or cerebrovascular events (MACCE). AIM: To assess the validity of the CHIP score in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We evaluated the performance of the CHIP score on 8341 CTO PCIs from the Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) performed at 44 centers between 2012 and 2023. RESULTS: In our cohort, 7.8% (n = 647) of patients had a CHIP score of 0, 50.2% (n = 4192) had a CHIP score of 1-2, 26.2% (n = 2187) had a CHIP score of 3-4, 11.7% (n = 972) had a CHIP score of 5-6, 3.3% (n = 276) had a CHIP score of 7-8, and 0.8% (n = 67) had a CHIP score of 9+. The incidence of MACCE for a CHIP score of 0 was 0.6%, reaching as high as 8.7% for a CHIP score of 9+, confirming that a higher CHIP score is associated with a higher risk of MACCE. The estimated increase in the risk of MACCE per one score unit increase was 100% (95% confidence interval [CI]: 65%-141%). The AUC of the CHIP score model for predicting MACCE in our cohort was 0.63 (95% CI: 0.58-0.67). There was a positive correlation between the CHIP score and the PROGRESS-CTO MACE score (Spearman's correlation: 0.37; 95% CI: 0.35-0.39; p < 0.001). CONCLUSIONS: The CHIP score has modest predictive capacity for MACCE in CTO PCI.