International survey of chronic total occlusion percutaneous coronary intervention operators.

BACKGROUND: Contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) practice has received limited study. AIM: To examine the contemporary CTO PCI practice. METHODS: We performed an online, anonymous, international survey of CTO PCI operators. RESULTS: Five hundred forty-five CTO PCI operators and 190 interventional cardiology fellows with an interest in CTO PCI participated in this survey. Almost half were from the United States (41%), most (93%) were men, and the median h/week spent in the hospital was 58. Median annual case numbers were 205 (150-328) for PCIs and 20 (5-50) for CTO PCIs. Almost one-fifth (17%) entered CTO cases into registries, such as PROGRESS-CTO (55%) and EuroCTO (20%). More than one-third worked at academic institutions (39%), 31% trained dedicated CTO fellows, and 22% proctored CTO PCI. One-third (34%) had dedicated CTO PCI days. Most (51%) never discharged CTO patients the same day, while 17% discharged CTO patients the same day >50% of the time. After successful guidewire crossing, 38% used intravascular imaging >90% of the time. Most used CTO scores including J-CTO (81%), PROGRESS-CTO (35%), and PROGRESS-CTO complications scores (30%). Coronary artery perforation was encountered within the last month by 19%. On a scale of 0-10, the median comfort levels in treating coronary artery perforation were: covered stents 8.8 (7.0-10), coil embolization 5.0 (2.1-8.5), and fat embolization 3.7 (0.6-7.3). Most (51%) participants had a complication cart/kit and 25% conducted regular complication drills with catheterization laboratory staff. CONCLUSION: Contemporary CTO PCI practices vary widely. Further research on barriers to following the guiding principles of CTO PCI may improve patient outcomes.

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.

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.

Electrocautery-assisted re-entry to resolve bilateral aorto-ostial chronic total occlusions due to leaflet obstruction following transcatheter aortic valve replacement.

Coronary artery obstruction is a rare but life-threatening complication of transcatheter aortic valve replacement (TAVR). While urgent percutaneous coronary intervention has been described in cases of acute occlusion, little is known about the interventional management of obstruction once it has occurred in the chronic setting. We describe a case in which electrocautery-assisted re-entry was successfully utilized to manage the right coronary artery and left main chronic total occlusion due to leaflet-induced coronary artery obstruction after TAVR.

Chronic total occlusion percutaneous coronary intervention in heart transplant patients.

Cardiac allograft vasculopathy (CAV) is frequently observed after heart transplant (HT), and represents one of the main causes of chronic rejection, graft loss, and death. While the role of percutaneous coronary intervention (PCI) is well established in the management of CAV in cases of nonocclusive stenoses, the outcomes and technical aspects of this procedure in chronic total occlusions (CTOs) are unknown. We describe our experience with three cases in which CTO PCI was indicated to treat CAV in HT recipients, and we discuss the peculiarities and therapeutic approach to this challenging patient population. In particular, all patients were asymptomatic for angina, and CTO PCI was indicated to promote recovery of left ventricular function, extend graft survival, and/or protect from future ischemic events. CTO PCI was performed using hybrid techniques and was successful in all three cases. Intravascular imaging was used in all cases to maximize the durability of the procedure.

Role of the retrograde Carlino technique for chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is scarce data on the outcomes of the Carlino technique for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We aimed to investigate the indications and outcomes of the Carlino technique as performed in the context of the retrograde approach. METHODS: We pooled CTO PCI cases where a retrograde Carlino technique was performed from high-volume operators at four centers. The Carlino technique was characterized according to its indication (achieving plaque/cap modification, clarifying microcatheter location within the vessel, resolving distal cap ambiguity) and was considered successful when it led to the desired outcome. RESULTS: A total of 43 patients were included. Occlusion complexity was very high (mean J-CTO score 3.3 ± 0.8). The two most common indications were understanding the anatomy of the occlusion and clarifying gear location (37.2%) and impenetrable distal cap (34.9%). The Carlino technique was successful in 88.4% of cases. Overall technical and procedural success was 86.0%. The most common successful crossing technique was reverse controlled antegrade and retrograde subintimal tracking (70.3%). No complications were attributed to the Carlino technique. CONCLUSIONS: We observed a high success rate of the retrograde Carlino technique, as well as overall technical and procedural success rates. No Carlino technique-related complications were observed. Additional data from larger registries are warranted to further confirm the safety and efficacy of this technique.

The contemporary role of protamine in the cardiac catheterization laboratory.

Access to the arterial circulation and full anticoagulation carries a risk of serious bleeding during and after percutaneous coronary intervention. Important sources of bleeding include the arterial access site and coronary artery perforation. Prompt and effective management of hemorrhagic complications is an essential interventional skill. Protamine sulfate is well-known as a heparin reversal agent. Despite this, there is heterogeneity in the use of protamine during interventional procedures. While protamine is generally well-tolerated, it is associated with a risk of hypersensitivity reaction, including anaphylaxis, among others. The purpose of this review is to summarize the existing evidence about and experience with the use of protamine sulfate in the setting of percutaneous coronary and structural interventional procedures.

Increased prescription dose for large vessel intravascular brachytherapy.

BACKGROUND: Most randomized studies testing the effectiveness of IVBT were limited to vessels less than 4 mm diameter. In fact, it is now common to treat vessels larger than 4 mm. Accordingly, the authors instituted a prescription dose increase to 34 Gy at 2 mm from source center for vessels greater than 4.0 mm. The increase in prescription dose to 34 Gy at 2 mm from center is substantial, being 50% higher than the conventional maximum of 23 Gy. AIM: To take a close look at group of patients treated to 34 Gy, and for whom follow-up angiograms are available. METHODS: Ten patients treated for ISR with a prescription dose of 34 Gy and for whom follow-up angiograms were available were studied. Beta-radiation brachytherapy was performed with a Novoste Beta-Cath System using a strontium-90 (beta) source (Best Vascular, Springfield, VA). Source lengths of 40 or 60 mm were used. A dose of 34 Gy was prescribed at 2 mm from the source center. RESULTS: Patients were re-catheterized from 2 to 21 months (median: 16 months) following IVBT, all for symptoms suggested of restenosis. All patients had some degree of ISR of the target vessel, but no IVBT-treated vascular segment showed angiographic signs of degeneration, dissection or aneurysm. CONCLUSION: The authors' clinical impression, along with detailed review of the 10 cases, suggest that using a 34 Gy prescription dose at 2 mm from source center does not result in increased toxicity.

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.

Balloon-assisted subintimal entry (BASE) in chronic total occlusion percutaneous coronary interventions.

BACKGROUND: There is limited data on the use of the balloon-assisted subintimal entry (BASE) technique in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of 155 CTO PCIs that utilized the BASE technique at 31 US and non-US centers between 2016 and 2023. RESULTS: The BASE technique was used in 155 (7.9%) of 1968 antegrade dissection and re-entry (ADR) cases performed during the study period. The mean age was 66 ± 10 years, 88.9% of the patients were men, and the prevalence of diabetes (44.6%), hypertension (90.5%), and dyslipidemia (88.7%) was high. Compared with 1813 ADR cases that did not use BASE, the target vessel of the BASE cases was more commonly the RCA and less commonly the LAD. Lesions requiring BASE had longer occlusion length (42 ± 23 vs. 37 ± 23 mm, p = 0.011), higher Japanese CTO (J-CTO) (3.4 ± 1.0 vs. 3.0 ± 1.1, p < 0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention chronic total occlusion) (1.8 ± 1.0 vs. 1.5 ± 1.0, p = 0.008) scores, and were more likely to have proximal cap ambiguity, side branch at the proximal cap, blunt/no stump, moderate to severe calcification, and proximal tortuosity. Technical (71.6% vs. 75.5%, p = 0.334) and procedural success (71.6% vs. 72.8%, p = 0.821), as well as major adverse cardiac events (MACE) (1.3% vs. 4.1%, p = 0.124), were similar in ADR cases that used BASE and those that did not. CONCLUSIONS: The BASE technique is used in CTOs with longer occlusion length, higher J-CTO score, and more complex angiographic characteristics, and is associated with moderate success but also low MACE.

External validation of the PROGRESS-CTO perforation risk score: Individual patient data pooled analysis of three registries.

BACKGROUND: Coronary artery perforation is one of the most feared and common complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: To assess the usefulness of the recently developed PROGRESS-CTO (NCT02061436) perforation risk score in independent cohorts. Individual patient-level data pooled analysis of three registries was performed. RESULTS: Of the 4566 patients who underwent CTO PCI at 25 centers, 196 (4.2%) had coronary artery perforation. Patients with perforations were older (69 ± 10 vs. 65 ± 10, p < 0.001), more likely to be women (19% vs. 13%, p = 0.009), more likely to have a history of prior coronary artery bypass graft (34% vs. 20%, p < 0.001), and unfavorable angiographic characteristics such as blunt stump (62% vs. 48%, p < 0.001), proximal cap ambiguity (52% vs. 34%, p < 0.001), and moderate-severe calcification (60% vs. 49%, p = 0.002). Technical success was lower in patients with perforations (73% vs. 88%, p < 0.001). The area under the receiver operating characteristic curve of the PROGRESS-CTO perforation risk model was 0.76 (95% confidence interval [CI], 0.72-0.79), with good calibration (Hosmer-Lemeshow p = 0.97). We found that the CTO PCI perforation risk increased with higher PROGRESS-CTO perforation scores: 0.3% (score 0), 2.3% (score 1), 3.1% (score 2), 5.5% (score 3), 7.5% (score 4), 14.6% (score 5). CONCLUSION: Given the good discriminative performance, calibration, and the ease of calculation, the PROGRESS-CTO perforation score may facilitate assessment of the risk of perforation in patients undergoing CTO PCI.

Failure patterns after intravascular brachytherapy for in-stent coronary restenosis.

INTRODUCTION: One strategy to improve the effectiveness of intravascular brachytherapy (IVBT) is to study its failures. Previous investigations described mostly discrete, focal recurrences, typically at the proximal or distal edges of the irradiated segment after plain angioplasty or bare metal stents. We reviewed failure patterns of 30 unselected drug-eluting stent (DES) patients who had follow-up angiograms for recurrence within their IVBT-treated vessel. METHODS: Records of 53 unselected IVBT patients treated between 2016 and 2021 were reviewed. Thirty of the 53 patients had at least one subsequent percutaneous intervention (PCI) for in-stent restenosis (ISR) after IVBT. Angiographic findings of those 30 patients with ISR within their previously irradiated vessel are reported here. RESULTS: Of the 30 patients, 21 (70%) developed recurrent ISR within the irradiated segment. Six of the 21 patients who failed within the irradiated segment also experienced ISR proximal or distal to the irradiated segment. Only 15 patients (50%) failed exclusively within the irradiated segment. In nine patients (30%), restenosis occurred proximally and/or distally to the irradiated segment, but not inside of the irradiated segment itself. CONCLUSIONS: We have shown here that 50% of failures after coronary IVBT for DES ISR occur exclusively within the irradiated segment. An additional 20% of patients had failure within and outside of the irradiated segment. These percentages suggest that a higher radiation dose might improve the long-term patency rates, a conclusion that should be tempered by the lack of universal follow-up.

Interventional cardiologists' perceptions of percutaneous coronary intervention quality measurement and feedback.

BACKGROUND: Interventional cardiologists receive feedback on their clinical care from a variety of sources including registry-based quality measures, case conferences, and informal peer interactions. However, the impact of this feedback on clinical care is unclear. METHODS: We interviewed interventional cardiologists regarding the use of feedback to improve their care of percutaneous coronary intervention (PCI) patients. Interviews were assessed with template analysis using deductive and inductive techniques. RESULTS: Among 20 interventional cardiologists from private, academic, and Department of Veterans Affairs practice, 85% were male, 75% performed at least 100 PCIs annually, and 55% were in practice for 5 years or more. All reported receiving feedback on their practice, including formal quality measures and peer learning activities. Many respondents were critical of quality measure reporting, citing lack of trust in outcomes measures and poor applicability to clinical care. Some respondents reported the use of process measures such as contrast volume and fluoroscopy time for benchmarking their performance. Case conferences and informal peer feedback were perceived as timelier and more impactful on clinical care. Respondents identified facilitators of successful feedback interventions including transparent processes, respectful and reciprocal peer relationships, and integration of feedback into collective goals. Hierarchy and competitive environments inhibited useful feedback. CONCLUSIONS: Despite substantial resources dedicated to performance measurement and feedback for PCI, interventional cardiologists perceive existing quality measures to be of only modest value for improving clinical care. Catherization laboratories should seek to integrate quality measures into a holistic quality program that emphasizes peer learning, collective goals and mutual respect.

Open-Channel Capillary Trees and Capillary Pumping.

Velocity of capillary flow in closed or open channels decreases as the flow proceeds down the length of the channel, varying as the inverse of the square root of time or as the inverse of travel distance. In order to increase the flow rate-and extend the duration of the flow-capillary pumps have been designed by mimicking the pumping principle of paper or cotton fibers. These designs provide a larger volume available for the wicking of the liquids. In microsystems for biotechnology, different designs have been developed based on experimental observation. In the present paper, the mechanisms at the basis of capillary pumping are investigated using a theoretical model for the flow in an open-channel "capillary tree" (i.e., an ensemble of channels with bifurcations mimicking the shape of a tree). The model is checked against experiments. Rules for obtaining better designs of capillary pumps are proposed; specifically, we find (1) when using a capillary tree with identical channel cross-sectional areas throughout, it is possible to maintain nearly constant flow rates throughout the channel network, (2) flow rate can be increased at each branch point of a capillary tree by slightly decreasing the areas of the channel cross section and decreasing the channel lengths at each level of ramification within the tree, and (3) higher order branching (trifurcations vs bifurcations) amplify the flow rate effect. This work lays the foundation for increasing the flow rate in open microfluidic channels driven by capillary flow; we expect this to have broad impact across open microfluidics for biological and chemical applications such as cell culture, sample preparation, separations, and on-chip reactions.

Sex-Based Differences in Chronic Total Occlusion Management.

ᅟ: Chronic total occlusions (CTOs) are an important and increasingly recognized subgroup of coronary lesions, documented in at least 30%, but up to 52% of patients with coronary artery disease (CAD) undergoing coronary angiography. Percutaneous coronary intervention (PCI) of these lesions is increasingly pursued, with excellent success rates. PURPOSE OF REVIEW: It is known that gender differences exist in the presentation of CAD, as well as in clinical outcomes after routine PCI; however, it is not well described how these differences pertain to management of CTOs. This review summarizes the available data regarding sex-based differences in CTO management and outcomes. RECENT FINDINGS: Women comprise approximately 20% of CTO registry and trial participants. As has been demonstrated in PCI studies, women comprise a minority of patients in CTO PCI registries and trials. Sex-based differences exist in complication rates, collateral formation, and outcomes and need further evaluation in future studies.

Caliber and fitness of the axillary artery as a conduit for large-bore cardiovascular procedures.

OBJECTIVES: We sought to describe the caliber and vascular health of the subclavian and axillary arteries as related to their potential utilization in complex cardiovascular procedures. BACKGROUND: Patients referred for advanced catheter-based therapies frequently have lower extremity peripheral vascular disease that may prohibit the use of large bore arterial catheters. Utilization of the upper extremity peripheral vasculature is rarely considered as an alternative access strategy. This may be due in part to a lack of familiarity with the thoracic vasculature. METHODS AND RESULTS: 208 consecutive patients undergoing routine CTA prior to transcatheter aortic valve replacement were retrospectively evaluated in a systematic analysis of upper and lower extremity vasculature. Minimal luminal diameters (MLDs) for the axillary arteries and iliofemoral arteries were 6.0 ± 1.1 mm and 6.6 ± 1.8 mm respectively. Compared to the iliofemoral arteries, the axillary arteries demonstrated substantially lower rates of significant stenosis (2% vs. 12%, p < 0.01) and significantly lower rates of moderate to severe calcification disease (9% vs. 64%, p < 0.01). Diabetes and tobacco use were independently associated with smaller axillary artery caliber by MLD (p < 0.01) but not with significant stenotic disease. CONCLUSIONS: The axillary arteries are slightly smaller but less frequently diseased than the corresponding iliofemoral vessels.

Intentional creation of dissection flaps to treat perforations during chronic total occlusion percutaneous coronary intervention.

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) carries a non-negligible risk of coronary perforation. Definitive treatment of a proximal large vessel perforation often requires the use of covered stents; however, the latter carry significant risk of restenosis and thrombosis, and is not feasible if wire control of the distal vessel has not been achieved. We describe two cases of target vessel perforations during CTO PCI which were treated by the intentional creation of dissection flaps using the subintimal tracking and re-entry technique to seal the perforation.

Controlled antegrade and retrograde subintimal tracking (CART) for recanalisation of chronic total occlusions.

BACKGROUND: Controlled antegrade and retrograde subintimal tracking (CART) is rarely performed in contemporary chronic total occlusion (CTO) percutaneous coronary intervention (PCI). AIMS: We aimed to analyse the indications, procedural characteristics, and outcomes of CART at a high-volume CTO programme. METHODS: We included all patients undergoing a retrograde CTO PCI in which CART was performed at our institution between January 2019 and November 2023. The primary endpoint was technical success. RESULTS: Of 1,582 CTO PCI, the retrograde approach was performed in 603 procedures (38.1%), and CART was used in 45 cases (7.5%). The mean age was 69.1±10.3 years, 93.3% were male, and prior coronary artery bypass graft surgery was present in 68.9%. The most common target CTO vessel was the right coronary artery (48.9%). Anatomical complexity was high (Multicentre CTO Registry of Japan [J-CTO] score of 3.6±0.9). The most common collateral used for CART was a saphenous vein graft (62.2%). Advanced calcium modification was required in 15.6% of cases. CART was successful in 73.3%. Technical and procedural success was 82.2%. Coronary perforation was diagnosed in 4 subjects (8.9%), but only 1 patient (2.2%) suffered tamponade and required pericardiocentesis. No other in-hospital major adverse cardiac events were diagnosed. CONCLUSIONS: CART is a useful technique in selected, very complex CTOs tackled with the retrograde approach. Success rates were high, while complication rates were low, considering the high anatomical complexity and baseline patient risk.

Extreme coronary radiation doses from intravascular brachytherapy.

PURPOSE: To evaluate coronary artery integrity after very high radiation doses from intravascular brachytherapy (IVBT) in the setting of source asymmetry. METHODS: Ten patients treated for right coronary artery (RCA) in-stent restenosis (ISR) between 2017 and 2021 and for whom follow-up angiograms were available were identified from departmental records. Procedural angiograms, taken to document source position, were used to estimate vascular wall doses. The 2.5 mm proximal source marker was used to estimate the distance from source center to the media and adventitia. Distances were converted to dose (Gy) using the manufacturers' dose fall-off table, measured in water. Follow-up films were scrutinized for any sign of late vascular damage. RESULTS: The average minimal distance from catheter center to the adjacent media and the adventitia was 0.9 mm (±0.2) mm and 1.4 mm (±0.2), respectively. The average maximum media and adventitial doses adjacent to the source were 75 Gy (±26) and 39 Gy (±14), respectively. Follow-up angiograms were available from 0.6 years to 3.9 years following IVBT (median: 1.6 years). No IVBT-treated vascular segment showed signs of degeneration, dissection or aneurysm. CONCLUSION: IVBT vascular wall doses are frequently far higher than prescribed. The lack of complications in this unselected group of patients gives a modicum of reassurance that raising the prescription dose is unlikely to lead to a sudden appearance of complications.

Comparative Analysis of Polymer Versus Non-Polymer Jacketed Wires in Chronic Total Occlusion Percutaneous Coronary Intervention.

There is significant variation in wire utilization patterns for chronic total occlusion (CTO) percutaneous coronary intervention. This study aimed to compare the outcomes of polymer-jacketed wires (PJWs) versus non-PJWs in anterograde procedures. We analyzed clinical and angiographic characteristics, and procedural outcomes of 7,575 anterograde CTO percutaneous coronary interventions that were performed at 47 centers between 2012 and 2023. Cases in which PJWs were exclusively used were classified in the PJW group, whereas cases where at least one non-PJW was employed were classified in the non-PJW group. Study end points were as follows: technical success, coronary perforation, major adverse cardiac event. PJWs were exclusively used in 3,481 cases (46.0%). These cases had lower prevalence of proximal cap ambiguity, blunt stump, and moderate/severe calcification. They also had lower Japanese CTO (J-CTO), Prospective Global Registry for the Study of Chronic Total Occlusion (PROGRESS-CTO), and PROGRESS-CTO complications scores, higher technical success (94.3% vs 85.7%, p <0.001), and lower perforation rates (2.2% vs 3.2%, p = 0.013). Major adverse cardiac event rates did not differ between groups (1.3% vs 1.5%, p = 0.53). Exclusive use of PJWs was independently associated with higher technical success in both the multivariable (odds ratio [OR] 2.66, 95% confidence interval [CI] 2.13 to 3.36, p <0.001) and inverse probability of treatment weight analysis (OR 2.43, 95% CI 2.04 to 2.89, p <0.001). Exclusive use of PJWs was associated with lower risk of perforation in the multivariable analysis (OR 0.69, 95% CI 0.49 to 0.95, p = 0.02), and showed a similar trend in the inverse probability of treatment weight analysis (OR 0.77, 95% CI 0.57 to 1.04, p = 0.09). Exclusive use of PJWs is associated with higher technical success and lower perforation risk in this non-randomized series of patients.