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.

Equipment entrapment/loss during chronic total occlusion percutaneous coronary intervention.

BACKGROUND: There is limited data on equipment loss or entrapment during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We analyzed the baseline clinical and angiographic characteristics and outcomes of equipment loss/entrapment at 43 US and non-US centers between 2017 and 2023. RESULTS: Equipment loss/entrapment was reported in 40 (0.4%) of 10 719 cases during the study period. These included guidewire entrapment/fracture (n = 21), microcatheter entrapment/fracture (n = 11), stent loss (n = 8) and balloon entrapment/fracture/rupture (n = 5). The equipment loss/entrapment cases were more likely to have moderate to severe calcification, longer lesion length, higher J-CTO and PROGRESS-CTO complications scores, and use of the retrograde approach compared with the remaining cases. Retrieval was attempted in 71.4% of the guidewire, 90.9% of the microcatheter, 100% of the stent loss, and 100% of the balloon cases, and was successful in 26.7%, 30.0%, 50%, and 40% of the cases, respectively. Procedures complicated by equipment loss/entrapment had higher procedure and fluoroscopy time, contrast volume and patient air kerma radiation dose, lower procedural (60.0% vs 85.6%, P less than .001) and technical (75.0% vs 86.8%, P = .05) success, and higher incidence of major adverse cardiac events (MACE) (17.5% vs 1.8%, P less than .001), acute MI (7.5% vs 0.4%, P less than .001), emergency coronary artery bypass graft (CABG) (2.5% vs 0.1%, P = .03), perforation (20.0% vs 4.9%, P less than .001), and death (7.5% vs 0.4%, P less than .001). CONCLUSIONS: Equipment loss is a rare complication of CTO PCI; it is more common in complex CTOs and is associated with lower technical success and higher MACE.

Distal Radial Access in Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From the PROGRESS-CTO Registry.

BACKGROUND: The outcomes of distal radial access (dRA) in chronic total occlusion percutaneous coronary intervention (CTO-PCI) have received limited study. METHODS: We compared the clinical, angiographic, and procedural characteristics of 120 CTO-PCIs performed via dRA access with 2625 CTO-PCIs performed via proximal radial access (pRA) in a large, multicenter registry. RESULTS: The dRA group had lower mean PROGRESS-CTO score than the pRA group (1.0 ± 1 vs 1.2 ± 1, respectively; P=.05), while J-CTO score (2.4 ± 1.2 vs 2.3 ± 1.3; P=.43) and PROGRESS-CTO Complications score (2.8 ± 1.8 vs 2.6 ± 1.9; P=.16) were similar in the dRA vs pRA groups, respectively. Technical success was similar in the 2 groups (90% dRA vs 86% pRA; P=.14). Concomitant use of femoral access did not alter procedural success. The incidence of major periprocedural adverse cardiac events was similar in the 2 groups (0.8% dRA vs 2.4% pRA; P=.26), whereas the incidence of tamponade requiring pericardiocentesis was lower with dRA (0% dRA vs 4.69% pRA; P<.001), as was air kerma radiation dose (median, 1.7 Gy; interquartile range [IQR], 0.97-2.63 Gy in the dRA group vs median, 2.27 Gy; IQR, 1.2-3.9 Gy in the pRA group; P<.001). CONCLUSIONS: Use of dRA in CTO-PCI is associated with similar procedural success and risk of complications as compared with pRA.

Chronic total occlusion percutaneous coronary intervention in octogenarians and nonagenarians.

OBJECTIVE: The outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in octogenarians and nonagenarians have received limited study. METHODS: We compared in-hospital outcomes of CTO PCI between patients ≥80 vs. <80-years-old in 6233 CTO PCIs performed between 2012 and 2020 at 33 U.S. and international centers. RESULTS: There were 415 octogenarians and nonagenarians in our study (7% of the total population). Compared with younger patients, octo- and nonagenarians were less likely to be men (73% vs. 83.2%, p < 0.0001) and more likely to have atrial fibrillation (27% vs. 12%, p < 0.0001) and prior coronary artery bypass graft surgery (CABG) (43% vs. 29%, p < 0.0001). They were more likely to have CTOs with moderate/severe calcification (71% vs. 46%, p < 0.0001), but had similar mean J-CTO scores (2.5 ± 1.3 vs. 2.4 ± 1.3, p = 0.08). They had lower technical and procedural success (82.2% vs. 86.3%, p = 0.0201; 80.3% vs. 84.8%, p = 0.016, respectively) and higher incidence of in-hospital major adverse cardiovascular events (3.4% vs. 1.8%, p = 0.021). On multivariable analysis PCI in octo- and nonagenarians was not independently associated with technical and procedural success or with in-hospital MACE. CONCLUSION: CTO PCI is feasible in octo- and nonagenarians, although success rates are lower, and the risk of complications is higher compared with younger patients, likely related to more comorbidities and higher coronary lesion complexity.

Impact of Successful Chronic Total Occlusion Percutaneous Coronary Interventions on Subsequent Clinical Outcomes.

BACKGROUND: The impact of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on angina and subsequent incidence of major adverse cardiovascular event (MACE) rate remains controversial. METHODS: We compared patient- reported angina change and the incidence of MACE (defined as death, myocardial infarction [MI], target-vessel revascularization) between successful vs failed CTO-PCI in 1612 patients participating in a large, multicenter registry. RESULTS: CTO-PCI was successful in 1387 patients (86%). Compared with failed CTO-PCI, successful CTO-PCI patients were less likely to have history of heart failure (33% vs 41%; P=.02), prior MI (49% vs 62%; P<.01), or prior coronary revascularization (63% vs 71% [P=.03] for PCI and 30% vs 40% [P<.01] for coronary artery bypass graft surgery). Patients in the successful CTO-PCI group had lower J-CTO scores (2.4 ± 1.3 vs 3.1 ± 1.1; P<.01) and lower PROGRESS-CTO Complications scores (1.1 ± 1.0 vs 1.6 ± 1.0; P<.01). After a mean follow-up of 181 ± 153 days, patients with successful PCI were more likely to have angina improvement (83% vs 38%; P<.01) and had lower incidence of 1-year MACE (8% vs 15%; P<.01), death (3% vs 7%; P<.01), and MI (2% vs 4%; P=.02). On multivariable analysis, however, CTO-PCI success was not independently associated with MACE. CONCLUSION: Compared with failed CTO-PCI, successful CTO-PCI is associated with better angina improvement and lower incidence of MACE (on univariable analysis) during follow-up.

Follow-up Outcomes After Chronic Total Occlusion Percutaneous Coronary Intervention in Patients With and Without Prior Coronary Artery Bypass Graft Surgery: Insights From the PROGRESS-CTO Registry.

BACKGROUND: Long-term outcomes of patients with prior coronary artery bypass graft (CABG) surgery undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have received limited study. METHODS: We compared the clinical and angiographic characteristics and procedural and follow-up outcomes of patients with and without prior CABG in a multicenter international registry. RESULTS: Of the 1572 patients included in this analysis, a total of 498 (32%) had prior CABG. Prior CABG patients had higher J-CTO scores (2.9 ± 1.1 vs 2.2 ± 1.3; P<.001) and were less likely to undergo PCI of the left anterior descending artery (16.7% vs 29.6%; P<.001). The retrograde technique was used more often (47.4% vs 28.2%; P<.001) and was successful more often (27.4% vs 17.1%; P<.001) in the prior CABG group vs the non-prior CABG group. Technical success was lower in prior CABG patients (82.6% vs 87.9%; P<.01) with similar incidence of in-hospital major adverse cardiovascular events (3.4% vs 3%; P=.65), although in-hospital mortality was higher in the prior CABG group (2.4% vs 1.0%; P=.04). At 1-year follow-up, the composite endpoint of death, myocardial infarction, and revascularization was higher in prior CABG patients (21.79% vs 12.73%; hazard ratio, 1.76; 95% confidence interval, 1.27-2.45; P<.001). CONCLUSION: Compared with non-prior CABG patients, prior CABG patients undergoing CTO-PCI had lower technical success and higher incidence of acute and follow-up adverse cardiovascular events.

Retrograde Chronic Total Occlusion Percutaneous Coronary Intervention via Saphenous Vein Graft.

OBJECTIVES: The aim of this study was to examine the use of saphenous vein grafts (SVGs) for retrograde crossing during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: The use of SVGs for retrograde crossing during CTO PCI has received limited study. METHODS: A total of 1,615 retrograde CTO PCIs performed between 2012 and 2019 at 25 centers were examined. Clinical, angiographic, and technical characteristics and procedural outcomes were compared among retrograde cases via SVGs (SVG group) versus other collateral vessels (non-SVG group). RESULTS: Retrograde CTO PCI via SVGs was performed in 189 cases (12%). Patients in the SVG group were older (mean age 70 ± 9 years vs. 64 ± 10 years; p < 0.01) and had higher rates of prior myocardial infarction (62% vs. 51%; p < 0.01) and prior PCI (81% vs. 70%; p < 0.01). They were more likely to have moderate or severe calcification (81% vs. 65%; p < 0.01) and moderate or severe tortuosity (53% vs. 44%; p = 0.02) and had similar J-CTO (Multicenter CTO Registry in Japan) scores (3.2 ± 1.0 vs. 3.1 ± 1.1; p = 0.13) but higher PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) scores (4.7 ± 1.7 vs. 3.1 ± 1.1; p < 0.01). Technical (85% vs. 78%; p = 0.04) and procedural (81% vs. 74%; p = 0.04) success rates were higher in the SVG group, with no difference in in-hospital major adverse events (6.4% vs. 4.4%; p = 0.22). Contrast volume was lower in the SVG group (225 ml [173 to 325 ml] vs. 292 ml [202 to 400 ml]; p < 0.01). CONCLUSIONS: Use of SVGs for retrograde crossing is associated with higher rates of technical and procedural success and similar rates of in-hospital major adverse cardiac events compared with retrograde CTO PCI via other collateral vessels.

Outcomes of subintimal plaque modification in chronic total occlusion percutaneous coronary intervention.

BACKGROUND: When crossing into the distal true lumen fails during chronic total occlusion (CTO) percutaneous coronary intervention (PCI), subintimal plaque modification (SPM) is often performed to restore antegrade flow and facilitate subsequent lesion recanalization. METHODS: Between January 2012 and May 4, 2019, 4,659 CTO PCIs were included in the PROGRESS-CTO registry, of which 935 (20%) had a prior unsuccessful attempt. Of those 935 patients, 119 (13%) had prior SPM. We analyzed the outcomes of the 58 SPM procedures for which data were available, as well as the outcomes of the 60 subsequent CTO PCI attempts. RESULTS: Mean patient age was 67 ± 9 years and 86% were men. Patients had high prevalence of cardiovascular risk factors such as dyslipidemia (91%), hypertension (93%) diabetes (48%), prior PCI (61%), and prior coronary artery bypass graft surgery (47%). The target CTO lesions often had proximal cap ambiguity (54%), moderate/severe calcification (73%), moderate/severe tortuosity (63%), and high J-CTO score (mean 3.2 ± 1.1). The technical and procedural success of subsequent CTO PCI were high (83% for both) with an acceptable rate of in-hospital major adverse cardiovascular events (3.3%). Technical and procedural success were higher for repeat attempts that were performed ≥60 days after the index CTO PCI (94% vs. 69%, p = .015). Median (interquartile range) subsequent procedure time was 147 (100, 215) min, contrast volume was 185 (150, 260) ml, and air kerma radiation dose was 2.5 (1.4, 4.2) Gray. CONCLUSION: Repeat CTO PCI attempts after SPM are associated with high likelihood for successful revascularization with acceptable risks.

Impact of concomitant treatment of non-chronic total occlusion lesions at the time of chronic total occlusion intervention.

BACKGROUND: During chronic total occlusion (CTO) percutaneous coronary intervention (PCI), sometimes non-CTO lesions are also treated. METHODS: We compared the clinical and procedural characteristics and outcomes of CTO PCIs with and without concomitant treatment of a non-CTO lesion in a contemporary multicenter CTO registry. RESULTS: Of the 3598 CTO PCIs performed at 21 centers between 2012 and 2018, 814 (23%) also included PCI of at least one non-CTO lesion. Patients in whom non-CTO lesions were treated were older (65 ±â€¯10 vs. 64 ±â€¯10 years, p = 0.03), more likely to present with an acute coronary syndrome (32% vs. 23%, p < 0.01), and less likely to undergo PCI of a right coronary artery (RCA) CTO (46% vs. 58%, p < 0.01). The most common non-CTO lesion location was the left anterior descending artery (31%), followed by the circumflex (29%) and the RCA (25%).Combined non-CTO and CTO-PCI procedures had similar technical (88% vs. 87%, p = 0.33) and procedural (85% vs. 85%, p = 0.74) success and major in-hospital complication rates (3.4% vs. 2.7%, p = 0.23), but had longer procedure duration (131 [88, 201] vs. 117 [75, 179] minutes, p < 0.01), higher patient air kerma radiation dose (3.0 [1.9, 4.8] vs. 2.8 [1.5, 4.6] Gray, p < 0.01) and larger contrast volume (300 [220, 380] vs. 250 [180, 350] ml, p < 0.01). CONCLUSIONS: Combined CTO PCI with PCI of non-CTO lesions is associated with similar success and major in-hospital complication rates compared with cases in which only CTOs were treated, but requires longer procedure duration and higher radiation dose and contrast volume.

Left Main Chronic Total Occlusion Percutaneous Coronary Intervention: A Case Series.

BACKGROUND: Left main coronary artery (LMCA) chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. METHODS: We reviewed 4436 CTO-PCIs performed in 4340 patients between 2012 and 2018 at 25 sites. LMCA-CTO-PCI was performed in 20 cases (0.45%). We examined the clinical and angiographic characteristics and procedural outcomes of these cases. RESULTS: Mean patient age was 68 ± 11 years and 65% were men. Most patients (85%) had undergone prior coronary artery bypass graft surgery and had a protected left main. Mean J-CTO score was 2.7 ± 1.3, mean PROGRESS-CTO score was 1.3 ± 1.1, and mean PROGRESS-CTO Complications score was 3.8 ± 1.9. Antegrade-wire escalation was the most common successful crossing strategy (50%), followed by retrograde crossing (30%) and antegrade dissection/re-entry (10%). Technical and procedural success rates were both 85%. One patient with failed LMCA-CTO-PCI had periprocedural myocardial infarction. Median procedure time was 178 minutes (interquartile range [IQR], 123-250 minutes), median contrast volume was 190 mL (IQR, 133-339 mL), and patient air kerma radiation dose was 2.6 Gray (IQR, 1.3-3.9 Gray). CONCLUSIONS: LMCA-CTO-PCI is infrequent, is performed mostly in patients with prior coronary artery bypass graft surgery, and is associated with good procedural outcomes.

In-Hospital Outcomes of Chronic Total Occlusion Percutaneous Coronary Interventions in Patients With Prior Coronary Artery Bypass Graft Surgery.

BACKGROUND: We examined the procedural outcomes of chronic total occlusions (CTO) percutaneous coronary interventions in patients with prior coronary artery bypass graft surgery (CABG). METHODS AND RESULTS: We compared the clinical, angiographic characteristics and outcomes of 3486 CTO interventions performed in patients with (n=1101) and without (n=2317) prior CABG at 21 centers. Prior CABG patients (32% of total cohort) were older (67±9 versus 63±10 years; P<0.001) and had more comorbidities and lower left ventricular ejection fraction (50% [40-58] versus 55% [45-60]; P<0.001). The CTO target vessel in prior CABG patients was the right coronary artery (56%), circumflex (26%), and left anterior descending artery (17%). The mean J-CTO (2.9±1.2 versus 2.2±1.3; P<0.001) and PROGRESS-CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention; 1.5±1.1 versus 1.2±1.0; P<0.001) score was higher in prior CABG patients. Retrograde (53% versus 30%, P<0.001) and antegrade dissection reentry (35% versus 28%; P<0.001) techniques were used more frequently in prior CABG patients. Prior CABG patients had lower technical (84% versus 89%; P<0.001) and procedural (82% versus 87%, P<0.001) success, but similar incidence of in-hospital major complications (3.1% versus 2.5%; P=0.287). In-hospital mortality (1% versus 0.4%; P=0.016) and coronary perforation (7.1% versus 3.1%; P<0.001) occurred more frequently in prior CABG patients, however, CABG patients had a lower incidence of pericardial tamponade (0.1% versus 1.0%; P=0.002) and pericardiocentesis (0% versus 1.3%; P<0.001). CONCLUSIONS: In a large multicenter CTO percutaneous coronary interventions registry, prior CABG patients had lower success rate but similar overall risk for complications, although mortality was higher and the incidence of tamponade was lower. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02061436.

Usefulness of Atherectomy in Chronic Total Occlusion Interventions (from the PROGRESS-CTO Registry).

There is limited data on the use of atherectomy during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We compared the clinical and procedural characteristics and outcomes of CTO PCIs performed with or without atherectomy in a contemporary multicenter CTO PCI registry. Between 2012 and 2018, 3,607 CTO PCIs were performed at 21 participating centers. Atherectomy was used in 117 (3.2%) cases: rotational atherectomy in 105 cases, orbital atherectomy in 8, and both in 4 cases. Patients in whom atherectomy was used, were older (68 ± 8 vs 64 ± 10 years, p <0.0001) and had higher Japan-chronic total occlusion score (3.0 ± 1.2 vs 2.4 ± 1.3, p <0.0001). CTO PCI cases in which atherectomy was used had similar technical (91% vs 87%, p = 0.240) and procedural (90% vs 85%, p = 0.159) success and in-hospital major adverse cardiac event (4% vs 3%, p = 0.382) rates. However, atherectomy cases were associated with higher rates of donor vessel injury (4% vs 1%, p = 0.031), tamponade requiring pericardiocentesis (2.6% vs 0.4%, p = 0.012) and more often required use of a left ventricular assist device (9% vs 5%, p = 0.031). Atherectomy cases were associated with longer procedural duration (196 [141, 247] vs 119 [76, 180] minutes, p <0.0001), and higher patient air kerma radiation dose (3.6 [2.5, 5.6] vs 2.8 [1.6, 4.7] Gray, p = 0.001). In conclusion, atherectomy is currently performed in approximately 3% of CTO PCI cases and is associated with similar technical and procedural success and overall major adverse cardiac event rates, but higher risk for donor vessel injury and tamponade.

Procedural Outcomes of Percutaneous Coronary Interventions for Chronic Total Occlusions Via the Radial Approach: Insights From an International Chronic Total Occlusion Registry.

OBJECTIVES: This study examined the frequency and outcomes of radial access for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: Radial access improves the safety of PCI, but its role in CTO PCI remains controversial. METHODS: We compared the clinical, angiographic, and procedural characteristics of 3,790 CTO interventions performed between 2012 and 2018 via radial-only access (RA) (n = 747) radial-femoral access (RFA) (n = 844) and femoral-only access (n = 2,199) access at 23 centers in the United States, Europe, and Russia. RESULTS: Patients' mean age was 65 ± 10 years, and 85% were men. Transradial access (RA and RFA) was used in 42% of CTO interventions and significantly increased over time from 11% in 2012 to 67% in 2018 (p < 0.001). RA patients were younger (age 62 ± 10 years vs. 64 ± 10 years and 65 ± 10 years; p < 0.001), less likely to have undergone prior coronary artery bypass graft surgery (18% vs. 39% and 35%; p < 0.001), and less likely to have undergone prior PCI (60% vs. 63% and 66%; p = 0.005) compared with those who underwent RFA and femoral-only access PCI. RA CTO PCI lesions had lower J-CTO (Multicenter CTO Registry in Japan) (2.1 ± 1.4 vs. 2.6 ± 1.3 and 2.5 ± 1.3; p < 0.001) and PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) complication (2.3 ± 1.9 vs. 3.2 ± 2.0 and 3.2 ± 1.9; p < 0.001) scores. The mean sheath size was significantly smaller in the RA group (6.6 ± 0.7 vs. 7.0 ± 0.6 and 7.3 ± 0.8; p < 0.0001), although it increased with lesion complexity. Antegrade dissection re-entry (20% vs. 33% and 32%; p < 0.001) was less commonly used with RA, whereas use of retrograde techniques was highest with RFA (47%). The overall rates of technical success (89% vs. 88% vs. 86%; p = 0.061), procedural success (86% vs. 85% vs. 85%; p = 0.528), and in-hospital major complication (2.47% vs. 3.40% vs. 2.18%; p = 0.830) were similar in all 3 groups, whereas major bleeding was lower in the RA group (0.55% vs. 1.94% and 0.88%; p = 0.013). CONCLUSIONS: Transradial access is increasingly being used for CTO PCI and is associated with similar technical and procedural success and lower major bleeding rates compared with femoral-only access interventions. (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention [PROGRESS CTO]; NCT02061436).

The Hybrid Approach to Chronic Total Occlusion Percutaneous Coronary Intervention: Update From the PROGRESS CTO Registry.

OBJECTIVES: The aim of this study was to determine the techniques and outcomes of hybrid chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in a diverse group of patients and operators on 2 continents. BACKGROUND: CTO PCI has been evolving with constant improvement of equipment and techniques. METHODS: Contemporary outcomes of CTO PCI were examined by analyzing the clinical, angiographic, and procedural characteristics of 3,122 CTO interventions performed in 3,055 patients at 20 centers in the United States, Europe, and Russia. RESULTS: The mean age was 65 ± 10 years, and 85% of the patients were men, with high prevalence of diabetes (43%), prior myocardial infarction (46%), prior coronary artery bypass graft surgery (33%), and prior PCI (65%). The CTO target vessels were the right coronary artery (55%), left anterior descending coronary artery (24%), and left circumflex coronary artery (20%). The mean J-CTO (Multicenter Chronic Total Occlusion Registry of Japan) and PROGRESS CTO (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention) scores were 2.4 ± 1.3 and 1.3 ± 1.0, respectively. The overall technical and procedural success rate was 87% and 85%, respectively, and the rate of in-hospital major complications was 3.0%. The final successful crossing strategy was antegrade wire escalation in 52.0%, retrograde in 27.1%, and antegrade dissection re-entry in 20.9%; >1 crossing strategy was required in 40.9%. Median contrast volume, air kerma radiation dose, and procedure and fluoroscopy time were 270 ml (interquartile range: 200 to 360 ml), 2.9 Gy (interquartile range: 1.7 to 4.7 Gy), 123 min (interquartile range: 81 to 188 min) and 47 min (interquartile range: 29 to 77 min), respectively. CONCLUSIONS: CTO PCI is currently being performed with high success and acceptable complication rates among various experienced centers in the United States, Europe, and Russia. (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention [PROGRESS CTO]; NCT02061436).