The global chronic total occlusion (CTO) crossing algorithm was developed by experts to improve CTO percutaneous coronary intervention (PCI) outcomes but has yet to be validated using real-world data. To evaluate the association between adherence to the global CTO crossing algorithm and outcomes in CTO PCI. We examined the clinical and angiographic characteristics and procedural outcomes of 13,852 CTO PCIs at 43 US and non-US centers between 2012 and 2025. Adherence to the global CTO crossing algorithm was defined using 3 characteristics: proximal cap ambiguity, poor distal vessel quality, and use of primary antegrade dissection/re-entry (ADR). Among 13,852 CTO PCIs, 70% (n = 9,693) followed the global CTO crossing algorithm. Discordant cases more frequently involved the right coronary artery (61.5% vs 49.4%, p < 0.001) and exhibited greater complexity: longer occlusions, proximal cap ambiguity, blunt/no stump, poor distal vessel quality, and calcification (all p < 0.001). Discordant lesions also had a higher J-CTO score (2.55 ± 1.18 vs 2.23 ± 1.27; p < 0.001). Algorithm adherence was associated with higher crossing success with the initially selected technique (72.5% vs 49.4%), technical (87.9% vs 85.6%), and procedural success (86.7% vs 84.2%) (all p < 0.001). The incidence of perforation was lower in concordant cases (4.1% vs 6.1%; p < 0.001), although major adverse cardiovascular events (MACE) were comparable. On multivariable analysis, algorithm adherence was independently associated with technical success (odds ratio 1.22; 95% confidence interval 1.04-1.42; p = 0.014). Adherence to the global CTO crossing algorithm is associated with greater crossing success using the initially selected strategy, higher technical success, and similar in-hospital MACE.

Because of limited alternative options, intracoronary brachytherapy (ICBT) continues to be used for treating in-stent restenosis (ISR). We examined the indications, characteristics, and outcomes of ICBT in consecutive patients who underwent ICBT for ISR between January 2014 and December 2023 at a tertiary care center. During the study period 343 patients underwent ICBT of 502 lesions. The median patient age was 67 [60, 74] years, 73.4% of the patients were men, 77.3% had prior myocardial infarction, and 49.4% had prior coronary artery bypass graft surgery. The most common target vessel was the right coronary artery (38.7%) and 7.37% of lesions were in bypass grafts (33 saphenous vein grafts, 4 arterial grafts). A diffuse ISR pattern was found in 76.2% of lesions. Among the study lesions, 58.0% had 2 stent layers and 20.6% had 3 or more stent layers. Technical success was achieved in 96.1% of lesions. Follow-up was available for all patients with a mean follow-up of 701.5 days. The 3-year incidence of target lesion failure (TLF), target vessel myocardial infarction, and major adverse cardiac events were 36.4%, 17.2%, and 45.6%, respectively. In multivariable analysis, higher brachytherapy radiation dose was associated with a lower risk for TLF (aHR per 10 Gy: 0.73; 95% CI 0.54-0.93; p = 0.048). Repeat ICBT procedures had a higher incidence of TLF over 3 years compared with lesions treated with ICBT for the first time (log-rank test: p = 0.008). In conclusion, the 3-year incidence of TLF after ICBT is 36.4% and was lower with higher radiation dose and higher in lesions retreated with ICBT.

Background: Despite its use in patients awaiting heart transplant (HT), the impact of continuous inotropic support on short-term complications and long-term transplant outcomes remains unclear. This study evaluated inotrope use at the time of HT on perioperative complications and post-transplant survival, comparing outcomes at 30 days, 1 year, and 10 years with mechanical circulatory support (MCS) strategies including ECMO, IABP, and VADs. Methods: A retrospective analysis of the United Network for Organ sharing (UNOS) registry was performed, stratifying patients based on bridge strategy at the time of transplant: inotropes, ECMO, IABP, or VADs. Baseline characteristics, perioperative complications, and 30-day, 1-year, and 10-year post-transplant survival outcomes were analyzed across groups. Survival was assessed using Kaplan–Meier and Cox proportional hazards models. Results: Among the 11,801 heart transplant patients included, 9330 were on inotropes, 372 were on ECMO, 1072 received an IABP, and 1027 had VADs. Inotrope-bridged patients had significantly lower 30-day and 1-year mortality rates compared to the ECMO, IABP, and VAD groups. They also experienced reduced incidences of post-transplant dialysis and stroke. At 10 years, the inotrope group demonstrated superior long-term survival, with significantly lower mortality risk compared to ECMO (HR: 1.81; CI: 1.49–2.20, p < 0.001), IABP (HR: 1.19; CI: 1.06–1.32, p = 0.005), and VAD (HR: 1.18; CI: 1.10–1.27, p < 0.001). Conclusions: Continuous use of inotropes after waitlisting is associated with lower short, intermediate, and long-term mortality and does not lead to worse outcomes compared to ECMO, IABP, and VAD support. When mechanical support is not an option, inotropic therapy remains a viable and effective strategy.

The use of ionizing radiation during cardiac catheterization procedures poses risks to patients and medical staff, both directly and indirectly through orthopedic injuries caused by lead aprons. In this review, we summarize recent advances in radiation protection in the cardiac catheterization laboratory and discuss the effectiveness of traditional and novel radiation protection strategies and equipment.

OBJECTIVES:The levels of stress experienced by interventional cardiologists (IC) while performing procedures are not well known. The study examined the IC fellow and attending stress levels using both objective (heart rate variability [HRV]) and subjective (State Trait Anxiety Inventory [STAI]) metrics across the IC fellowship. METHODS:Six ICs participated in a study conducted over 2 periods, each lasting 10 to 14 days. Participants recorded their HRV using a Polar H10 chest strap (Polar Electro, Inc.) and a WHOOP 4.0 wrist band (WHOOP). The low frequency/high frequency (LF/HF) ratio, biomarker of sympathetic system activation, and related metrics were calculated using Kubios HRV Scientific software (Kubios Oy). RESULTS:A total of 217 procedures were analyzed. The median LF/HF ratio during procedures was significantly higher than at baseline (6.2 vs 4.1, P less than .001). Complex procedures had higher LF/HF ratio difference (procedural minus baseline LH/HF ratio) compared with non-complex procedures (2.55 vs 1.73, P less than .001), as did procedures with complications compared with uncomplicated procedures (3.01 vs 1.82, P less than .001) and emergent compared with non-emergent (3.51 vs 1.84, P less than .001) procedures. Procedures performed during period 2 (end of IC fellowship) had a lower LF/HF ratio difference (2.96 vs 1.10, P less than .001) but higher daily resting HRV (52 vs 46, P less than .001) compared with period 1 (beginning of IC fellowship). No correlation was detected between the pre- and post-procedural LF/HF ratio difference and the STAI score difference. CONCLUSIONS:Interventional cardiologists experience significant stress, as measured by the LF/HF ratio, during complex, emergency, and complicated procedures; however, stress levels decrease later in the IC fellowship.

BACKGROUND:The volume of percutaneous coronary intervention (PCI) at ambulatory surgical centers (ASC) is expected to increase. METHODS:We surveyed US interventional cardiologists with a 58-question, anonymous online survey to evaluate their knowledge of and perspectives on ASC PCI. RESULTS:A total of 114 interventional cardiologists (9 fellows) responded. Participants were most commonly between 45 and 54 years old (33%). Most participants identified as male (95%), white (58%), non-Hispanic (95%), and with an academic affiliation (61%); 13 participants (11%) were PCI operators at an ASC. Most participants (59%) were in support of ASC PCI, 63% were very confident in their ability to decide if a patient is well-suited for ASC PCI, and 43% were not familiar with national and state-level laws/regulations of ASC PCI. Perceived benefits of ASC PCI included positive patient experience (69%), greater efficiency (79%), and lower costs for patients (50%) and institutions (53%). Participants reported a high level of concern about private equity involvement in ASC PCI (58%), occurrence of adverse events away from the hospital (47%), lower quality of care (39%), inappropriate patient selection (40%), inadequate regulatory standards (35%), and institutional pressures (47%). Supporters of ASC PCI reported a better self-assessed knowledge of it and perceived more benefits with fewer concerns. CONCLUSIONS:Most survey participants expressed support for ASC PCI, citing benefits such as improved patient experience, greater efficiency, and reduced costs. However, participants expressed concern for private equity involvement and the risk of adverse events occurring away from the hospital setting.

OBJECTIVES:The impact of contrast type in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) remains controversial. The authors sought to evaluate the impact of contrast medium selection on patients undergoing CTO PCI. METHODS:The authors examined the outcomes of patients who underwent CTO PCI using iso-osmolar (iodixanol) vs pooled low-osmolar contrast media (LOCM) using data from the PROGRESS-CTO registry. RESULTS:Iodixanol was used in 1007 (18.1%) of 5558 CTO PCIs. Compared with pooled LOCM, iodixanol-treated patients were more likely to be women, were older, and more likely to have diabetes, dyslipidemia, hypertension, history of heart failure, myocardial infarction, coronary artery bypass graft surgery, and stroke. Iodixanol cases had higher complexity, with longer lesion length (35.25 ± 25.16 vs 28.91 ± 19.46 mm, P less than .001), higher prevalence of moderate or severe calcification (43% vs 37%, P less than .001) and moderate or severe proximal tortuosity (30% vs 24%, P less than .001), and higher Japanese-CTO (2.52 vs 2.17, P less than .001) and PROGRESS-CTO scores (1.30 vs 1.16, P less than .001). Iodixanol cases required longer procedure times but similar contrast volumes. Technical (85.3% vs 89.2%, P = .001) and procedural success (83.4% vs 87.3%, P = .001) were lower in iodixanol cases. Acute kidney injury (AKI) occurred in 6.4% of cases. After propensity score matching, the patients who received iodixanol had lower incidence of AKI (odds ratio [OR]: 0.67; 95% CI, 0.47, 0.97; P = .032) and a trend for lower incidence of major adverse renal or cardiovascular events (OR: 0.75; 95% CI, 0.56, 1.0; P = .061). CONCLUSIONS:AKI occurred in approximately 6% of CTO PCI cases. Iodixanol use was associated with a lower incidence of AKI, despite being used in more complex patients.

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 incidence of death (0.8% vs 0.4%; P = . 034), acute myocardial infarction (0.9%vs 0.4%; P = . 010), and perforation (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, 0.690.99; P = . 039). Conclusions. PAD patients undergoing CTO PCI have higher comorbidity burden, more complex CTOs, higher MACE, and lower technical success.

BACKGROUND:There is limited information on the use of drug-coated balloons (DCBs) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). AIMS:To assess the frequency and outcomes of DCB use in CTO PCI. OBJECTIVE:This study evaluated the frequency and outcomes of DCB use in a large, multicenter CTO PCI registry. METHODS:We analyzed 12,146 patients who underwent 12,157 successful CTO PCIs at 59 centers from 2018 to 2025. RESULTS:DCBs were used in 454 patients (3.7%) with increasing frequency over time (p = 0.020). A DCB-only strategy was used in 48.4% of the patients and a hybrid strategy combining DCBs and drug-eluting stents (DES) was used in 51.6% of patients. Patients treated with DCB (both strategies) had low prevalence of comorbidities. Compared with the DES cases, DCB only cases had favorable angiographic characteristics, lower mean J-CTO (Japanese CTO) score (1.83 ± 1.03 vs. 2.27 ± 1.23; p < 0.001), and similar technical success (96.3% vs. 97.3%; p = 0.640), and in-hospital major adverse cardiac events (MACE). The hybrid and DCB-only strategies had comparable technical success and in-hospital MACE. During a median follow-up of 323 (170-429) days, DCB only cases had lower MACE than the other strategies (hazard ratio [HR] 0.41, 95% CI 0.17-0.96, p = 0.040). After multivariable adjustment, the association remained significant (HR 0.39, 95% CI 0.16-0.92, p = 0.032). CONCLUSIONS:DCBs are increasingly being used in CTO PCI. A DCB only strategy was used in less complex lesions and was associated with similar technical success and in-hospital MACE compared with hybrid or DES strategies. A DCB only strategy was associated with lower long-term MACE.

Background: The effect of selecting the initial crossing strategy using the global chronic total occlusion (CTO) crossing algorithm on the outcomes of CTO percutaneous coronary intervention (PCI) has not been studied. Methods: We examined the clinical and angiographic characteristics and procedural outcomes of 13,852 CTO PCIs at 43 US and non-US centers between 2012 and 2025. Adherence to the global CTO crossing algorithm was defined using three key case characteristics - proximal cap ambiguity, poor distal vessel quality, and use of antegrade dissection/re-entry (ADR) as the primary strategy (Figure 1). Results: Among 13,852 CTO PCIs, 70% (n=9,693) adhered to the global CTO crossing algorithm. Adherence remained consistent over time. Patients in the discordant group (non-adherent) were younger and more likely to have a history of myocardial infarction (MI) rates, while the concordant group (adherent) had more unstable angina presentations and ad hoc procedures. Discordant cases more frequently targeted the right coronary artery (61.5% vs 49.4%, p<0.001) and exhibited greater complexity: longer occlusions, proximal cap ambiguity, blunt/no stump, poor distal vessel quality, and calcification (all p<0.001). Discordant lesions also had higher J-CTO (2.8±1.2 vs 2.1±1.1; p=0.001) and PROGRESS-CTO complication scores. The retrograde approach was utilized more often as the primary crossing strategy in concordant cases (15.3% vs 4.4%; p<0.001) but was less often the successful crossing strategy (14.9% vs 28.1%; p<0.001). Discordant procedures required more stents, longer duration, higher contrast volume, fluoroscopy time, and radiation dose (all p<0.001). Algorithm adherence was associated with higher crossing success with the initially selected technique (72.5% vs 49.4%), technical (87.9% vs 85.6%), and procedural success (86.7% vs 84.2%) (all p<0.001). The incidence of perforation was lower in concordant cases (4.1% vs 6.1%; p<0.001), although major adverse cardiovascular events (MACE) were comparable. On multivariable analysis algorithm adherence was independently associated with technical success (odds ratio 1.24; 95% confidence interval 1.06 – 1.44; p=0.007). Conclusions: Adhering to the global CTO crossing algorithm for initial crossing strategy selection is associated with higher likelihood of success with the initial strategy, better technical success rates, and similar in-hospital MACE.

Artificial intelligence (AI) has become pivotal in advancing medical care, particularly in interventional cardiology. Recent AI developments have proven effective in guiding advanced procedures and complex decisions. The authors review the latest AI-based innovations in the diagnosis of chronic total occlusions (CTO) and in determining the probability of success of CTO percutaneous coronary intervention (PCI). Neural networks and deep learning strategies were the most commonly used algorithms, and the models were trained and deployed using a variety of data types, such as clinical parameters and imaging. AI holds great promise in facilitating CTO PCI.

Background. Incorporating artificial intelligence (AI)-based clinical decision support in the cardiac catheterization laboratory could revolutionize percutaneous coronary intervention (PCI) and interventional cardiology (IC). Methods. The authors conducted a survey to assess the estimates of ICs regarding primary antegrade wiring (AW) crossing success, on a scale of 0% to 100%, for 15 chronic total occlusion (CTO) PCIs and compare them with estimates from a machine learning model (MLM). For the AI-based prediction, the authors used a MLM with an area under the curve of 0.78. The primary endpoint was the difference between AI-generated and human estimates. Results. A total of 130 ICs participated in the survey. The mean participant age was 51.7 +/- 10.6 years. The median difference between the AI and the human prediction was less than 20% for 6 cases, 20% to 30% for 7 cases, and greater than 30% for 2 cases. Successful AW-based crossing by an experienced CTO operator was achieved in 8 of 15 cases. The operator predictions aligned with the real-life outcomes in 9 of 15 cases (60.0%), while AI correctly predicted the success/failure of primary AW CTO crossing in 11 of 15 cases (73.3%). Operators with more experience (> 20 CTO PCIs annually) predicted higher success than less experienced operators for 5 cases. Operators who train dedicated advanced fellows predicted higher success in 6 cases and showed worse alignment with the AI prediction in 4 cases. Conclusions. The study shows that an MLM could assist CTO PCI planning by improving the accuracy of primary AW success predictions.

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 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 this independent cohort, although the JR-CTO score showed an association with crossing and technical failure, its predictive ability for both outcomes was modest.