Practice differences and knowledge gaps in complex and high-risk interventions between Japan and the USA: A case-based discussion.

Advances in percutaneous coronary intervention (PCI) devices and techniques have expanded the pool of eligible patients for revascularization, including those with comorbidities, reduced left ventricular function, or anatomical complexity (defined as CHIP: complex and high-risk interventions in indicated patients). CHIP interventions are typically performed by selected operators who specialize in complex PCI. This review presents two cases performed in the USA, to discuss the similarities and differences in practice patterns between CHIP operators in Japan and the USA. The first case involves a 58-year-old male presenting with myocardial infarction and cardiogenic shock, and the second case involves a 51-year-old female with a history of coronary artery bypass grafting presenting with a chronic total occlusion and PCI complicated by vessel perforation. The discussion focuses on appropriate patient selection, the role of the heart team approach for decision-making, the use of hemodynamic support devices, and other relevant factors. By comparing practices in Japan and the USA, this review highlights opportunities for knowledge exchange and potential areas for improving patient outcomes.

Impact of target vessel on the procedural techniques and outcomes of chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is limited information on the impact of the target vessel on the procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 11,580 CTO PCIs performed between 2012 and 2022 at 44 centers. RESULTS: The most common CTO target vessel was the right coronary artery (RCA) (53.1%) followed by the left anterior descending artery (LAD) (26.0%) and the left circumflex artery (LCX) (19.8%). RCA CTOs were longer and more complex, with a higher Japanese CTO score compared with LAD or LCX CTOs. Technical success was higher among LAD (88.8%) lesions when compared with RCA (85.7%) or LCX (85.8%) lesions (P less than .001). The incidence of major adverse cardiovascular events (MACE) was overall 1.9% (n = 220) and was similar among target vessels (P=.916). There was a tendency toward more frequent utilization of the retrograde approach for more proximal occlusions in all 3 target vessels. When compared with all other RCA lesions combined, distal RCA lesions had higher technical success (87.7% vs 85.3%; P=.048). Technical success was similar between various locations of LAD CTOs (P=.704). First/second/third obtuse marginal branch had lower technical success when compared with all other LCX lesion locations (82.7% vs 86.8%; P=.014). There was no association between MACE and CTO location in all 3 target vessels. CONCLUSIONS: LAD CTO PCIs had higher technical and procedural success rates among target vessels. The incidence of MACE was similar among target vessels and among various locations within the target vessel.

Incidence, mechanisms, treatment, and outcomes of donor vessel injury during percutaneous coronary interventions for chronic total occlusion.

BACKGROUND: Donor vessel injury is a potentially life-threatening complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). AIMS: Our goal was to examine the incidence, mechanisms, treatment, and outcomes of patients with donor vessel injury in a large multicenter CTO PCI registry. METHODS: We analyzed the baseline clinical and angiographic characteristics, and procedural outcomes of 12,349 CTO PCIs performed between 2012 and 2022 at 44 centers. RESULTS: The incidence of donor vessel injury was 0.35% (n = 43). The baseline clinical characteristics of patients with and without donor vessel injury were similar. Cases complicated by donor vessel injury were more complex with higher Japanese CTO score (2.9 ± 1.1 vs. 2.4 ± 1.3; p = 0.004) and lower procedural success rate (69.8% vs. 85.2%; p = 0.004). The retrograde approach was used more commonly in donor vessel injury cases (68.9% vs. 30.9%; p < 0.001). Most (53.5%) donor vessel injuries were guide catheter-induced, whereas 20.9% were due to donor vessel thrombosis. Of the 43 patients with donor vessel injury, 36 (83.7%) were treated with stenting and seven (16.3%) received a left ventricular assist device. The incidence of major adverse cardiovascular events (MACEs) was significantly higher in cases with donor vessel injury (23.3% vs. 2.0%; p < 0.001). Of the 43 patients with donor vessel injury, five patients (11.6%) experienced acute myocardial infarction and four patients (9.3%) died. CONCLUSIONS: Donor vessel injury, occurred in 0.35% of CTO PCIs performed by experienced operators, was mainly due to guide catheter-induced dissection or thrombosis and was associated with lower procedural success and higher MACE.

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.

Aortocoronary dissection during percutaneous coronary interventions for chronic total occlusion: Insights from the PROGRESS-CTO registry.

BACKGROUND: Aortocoronary dissection is a potentially serious complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined the incidence, mechanisms, treatment, and outcomes of aortocoronary dissection among 12,117 CTO PCIs performed between 2012 and 2022 in a large multicenter CTO PCI registry. RESULTS: The incidence of aortocoronary dissection was 0.2% (n = 27). Most aortocoronary dissections occurred in the right coronary artery (96.3%, n = 26). The baseline clinical characteristics of patients with and without aortocoronary dissection were similar, except for dyslipidemia, which was less common in patients with aortocoronary dissection (70.4% vs. 86.0%; p = 0.019). The retrograde approach was used more commonly among cases complicated by aortocoronary dissection (59.3% vs. 31.0%; p = 0.002). Technical (74.1% vs. 86.6%; p = 0.049) and procedural (70.4% vs. 85.2%; p = 0.031) success rates were lower among aortocoronary dissection cases, with a similar incidence of in-hospital major adverse cardiovascular events (3.7% vs. 2.0%; p = 0.541). Of the 27 patients with aortocoronary dissection, 19 (70.4%) were treated with ostial stenting and 8 (29.6%) were treated conservatively without subsequent adverse clinical outcomes. No patients required emergency surgery. Follow-up was available for 22 patients (81.5%): during a mean follow up of 767 (±562) days, the incidence of in-stent restenosis was 11.1% (n = 3). CONCLUSIONS: Aortocoronary dissection occurred in 0.2% of CTO PCIs performed by experienced operators, was associated with lower technical and procedural success, and was treated most commonly with ostial stenting. None of the patients required emergency cardiac surgery.

Equipment Utilization in Chronic Total Occlusion Percutaneous Coronary Interventions: Update From the PROGRESS-CTO Registry.

BACKGROUND: Guidewires and microcatheters are critical to the success of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We examined equipment utilization in 11,202 CTO-PCIs performed in 10,952 patients at 42 United States (US) and non-US centers between 2012 and 2022. RESULTS: Antegrade-only crossing was attempted in 7628 CTO-PCIs (68%) and the retrograde approach was used in 3574 CTO-PCIs (32%). The median number of guidewires used during antegrade wiring increased with lesion complexity from 3 (interquartile range [IQR], 2-4) for J-CTO score of 0 to 5 (IQR, 4-7) for J-CTO score of 5 (P<.001). Antegrade-only procedures had higher technical (90% vs 79%; P<.001) and procedural success (89% vs 77%; P<.001) compared with retrograde procedures. In antegrade-only cases, Pilot 200 (28%; Abbott Vascular) and Fielder XT (24%; Asahi Intecc) were the most frequently used guidewires, while Corsair (21%; Asahi Intecc) and Turnpike Spiral (20%; Vascular Solutions) were the most commonly used microcatheters. In retrograde cases, Sion (32%; Asahi Intecc) was the most common guidewire used, followed by Sion Black (22%; Asahi Intecc), Pilot 200 (22%), and Suoh 03 (19%; Asahi Intecc), while Corsair (16%) and Turnpike LP (11%) were the most commonly used microcatheters. The most successful guidewire for collateral crossing was the Sion (32%), followed by Sion Black (15%) and Suoh 03 (11%). CONCLUSION: Polymer-jacketed guidewires are the most commonly used guidewires for antegrade wiring, while non-polymer-jacketed, torquable guidewires are the most frequently used guidewires for retrograde techniques. Turnpike and Corsair are the most commonly used microcatheters in CTO-PCI.

Body Mass Index and Chronic Total Occlusion Percutaneous Coronary Intervention Outcomes: Is Overweight the New Normal?

BACKGROUND: Although high body mass index (BMI) is a known risk factor for the development of cardiovascular diseases, people who are overweight or obese often have better outcomes after cardiac procedures. Whether this "obesity paradox" is observed in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is unknown. Therefore, we examined the association of BMI with the outcomes of CTO-PCI in patients from the large, multicenter PROGRESS-CTO registry after stratifying patients into 3 BMI groups.

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.

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.

Saphenous Vein Graft Occlusion Following Native Vessel Chronic Total Occlusion Percutaneous Coronary Intervention.

BACKGROUND: Whether saphenous vein grafts (SVGs) should be occluded after successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) of the corresponding native vessel remains controversial. METHODS: We analyzed the clinical and angiographic characteristics and procedural outcomes of 51 patients who underwent SVG occlusion following successful CTO-PCI of the corresponding native vessel between 2015 and 2022 at 14 centers. RESULTS: Mean patient age was 71 ± 8 years and 80% were men. The most common CTO target vessel was the right coronary artery (41%), followed by the left circumflex (37%). Retrograde crossing through the SVG was the successful crossing strategy in 40 cases (78%). SVG occlusion was achieved with coils (1.9 ± 1.0) in 35 of 51 patients (69%) and vascular plugs in the other 16 cases (31%). All procedures were technically successful and the SVG was occluded completely (TIMI 0 flow) in 38 of the cases (75%), with the remaining cases having TIMI 1 flow. Follow-up was available for 37 patients (73%); during a mean follow-up of 312 days from CTO-PCI, the incidence of target-lesion failure due to restenosis was 5.4% (n = 2) with no other major events reported. CONCLUSION: Following native vessel CTO-PCI, SVG occlusion is often performed and is associated with favorable mid-term outcomes.

Gender differences in chronic total occlusion percutaneous coronary interventions: Insights from the PROGRESS-CTO registry.

BACKGROUND: There are limited data describing gender differences in patients undergoing chronic total occlusion (CTO) percutaneous coronary interventions (PCI). METHODS: We compared baseline clinical and angiographic characteristics and procedural outcomes between men and women among 9457 CTO PCIs performed at 38 centers between 2012 and 2022. RESULTS: A total of 7687 (81%) men and 1770 (19%) women were treated. Women were older, more likely to have comorbidities such as diabetes, hypertension and peripheral arterial disease, and had higher left ventricular ejection fraction. The most common CTO target vessel was the right coronary artery for both men (53%) and women (52%), although the left anterior descending artery was more frequently the target vessel among women (31% vs. 25%; p < 0.001). The J-CTO score (2.4 ± 1.3 vs. 2.2 ± 1.2; p < 0.001) as well as the PROGRESS-CTO score (1.3 ± 1.0 vs. 1.1 ± 1.0; p < 0.001) were higher among men. In female patients, antegrade wiring was more frequently the initial crossing strategy (87.6% vs. 82.4%; p < 0.001) and was more successful in crossing the target lesion (62.7% vs. 54.0%; p < 0.001) compared with men. Interventions in men required longer procedure time and fluoroscopy time, as well as higher air kerma radiation dose and contrast volume when compared to women. Technical (89% vs. 86%; p < 0.001) and procedural (87% vs. 84%; p = 0.003) success rates were higher among women. In-hospital major adverse cardiovascular events (MACE) were also higher in women (2.9% vs. 1.8%; p < 0.001). CONCLUSIONS: Women undergoing CTO PCI had higher technical and procedural success rates, but also higher in-hospital MACE compared with men.

Incidence, Mechanisms, Treatment, and Outcomes of Coronary Artery Perforation During Chronic Total Occlusion Percutaneous Coronary Intervention.

Coronary artery perforation is a feared complication of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Our objective was to describe the incidence, mechanisms, treatment, and outcomes of coronary artery perforation during CTO PCI. We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 10,454 CTO PCIs performed in 10,219 patients between 2012 and 2022. The incidence of coronary perforation was 4.9% (n = 503). Patients who experienced coronary perforation were older and were more likely to have had previous coronary artery bypass graft surgery. Procedures that resulted in perforation were more complex, with higher Japanese CTO and Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS-CTO) scores. Technical (66% vs 87%, p <0.001) and procedural (55% vs 87%, p <0.001) success rates were lower in perforation cases. The CTO target vessel was the most common perforation site (66%). The retrograde approach was responsible for the perforation in 47% of cases, and guidewire exit was the most common perforation mechanism. The proportion of Ellis class 1, 2, 3, and 3 -"cavity spilling" coronary perforations was 20%, 41%, 28%, and 11%, respectively. In 52% of perforations, 1 or more interventions were required: prolonged balloon inflation (23%), covered stent deployment (21%), coil embolization (6%), and/or autologous fat embolization (4%). Tamponade requiring pericardiocentesis occurred in 69 patients (14%). The incidence of major adverse cardiovascular events was higher in perforation cases (18% vs 1.3%, p <0.001). In conclusion, coronary artery perforation occurred in 4.9% of CTO PCIs performed by experienced operators and was associated with lower technical success and higher in-hospital major adverse cardiovascular events.

Intravascular lithotripsy in chronic total occlusion percutaneous coronary intervention: Insights from the PROGRESS-CTO registry.

BACKGROUND: The use of intravascular lithotripsy (IVL) in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 82 CTO PCIs that required IVL at 14 centers between 2020 and 2022. RESULTS: During the study period, IVL was used in 82 of 3301 (2.5%) CTO PCI procedures (0.4% in 2020 and 7% in 2022; p for trend < 0.001). Mean patient age was 69 ± 11 years and 79% were men. The prevalence of hypertension (95%), diabetes mellitus (62%), and prior PCI (61%) was high. The most common target vessel was the right coronary artery (54%), followed by the left circumflex (23%). The mean J-CTO and PROGRESS-CTO scores were 2.8 ± 1.1 and 1.3 ± 1.0, respectively. Antegrade wiring was the final successful crossing strategy in 65% and the retrograde approach was used in 22%. IVL was used in 10% of all heavily calcified lesions and 11% of all balloon undilatable lesions. The 3.5 mm lithotripsy balloon was the most commonly used balloon (28%). The mean number of pulses per lithotripsy run was 33 ± 32 and the median duration of lithotripsy was 80  (interquartile range: 40-103) seconds. Technical and procedural success was achieved in 77 (94%) and 74 (90%) cases, respectively. Two (2.4%) Ellis Class 2 perforations occurred after IVL use and were managed conservatively. CONCLUSION: IVL is increasingly being used in CTO PCI with encouraging outcomes.

Patient and Device Selection for Hemodynamic Support in High-Risk Percutaneous Coronary Intervention.

Coronary artery disease continues to advance resulting in the development of high-risk percutaneous interventions. This includes treatment of patients with multivessel disease, unprotected left main, acute myocardial infarction complicated by cardiogenic shock, and depressed left ventricular ejection fraction. As a result, mechanical circulatory support devices have evolved but require an understanding of patient hemodynamics, device mechanics, and access management. Trial data regarding device selection are limited by inclusion of cardiogenic shock patients, and observational studies are conflicted by selection bias, site familiarity with devices, and complication management; therefore, clinical judgment is required to treat high-risk patients appropriately.