Impact of chronic total occlusion on prognosis in cardiogenic shock due to unprotected left main coronary artery culprit lesion. Insights from the Polish Registry of Acute Coronary Syndromes.

BACKGROUND: Notwithstanding readily available revascularization, significant advancements in mechanical circulatory support, and pharmacological progress, cardiogenic shock (CS) secondary to unprotected left main culprit lesion-related acute myocardial infarction (ULMCL-related AMI) is associated with very high mortality. In this population, chronic total occlusion (CTO) is relatively frequent. AIMS: This study sought to assess the association between the presence of CTO and 12-month mortality in patients with CS due to ULMCL-related AMI. RESULTS: The study included consecutive patients admitted for AMI-related CS with ULMCL who underwent percutaneous coronary intervention (PCI) and were enrolled in the prospective Polish Registry of Acute Coronary Syndromes (PL-ACS) between January 2017 and December 2021. The patients were stratified into two groups based on the presence of at least one CTO. The primary endpoint was all-cause death at 12 months. Of the 250 included patients, 60 (24%) patients had one or more CTOs of a major coronary artery (+CTO), and in 190 (76%) patients, the presence of CTO was not observed (-CTO). The 12-month mortality rates for the +CTO and -CTO patients were 85% and 69.8%, respectively (P log-rank = 0.03). After multivariable adjustment for differences in the baseline characteristics, the presence of CTO remained significantly associated with higher 12-month mortality (hazard ratio, 1.423; 95% CI, 1.027-1.973; P = 0.034). CONCLUSIONS: Our analysis showed that in patients with CS due to ULMCL-related AMI treated with PCI, the presence of CTO is associated with worse 12-month prognosis.

Annual operator volume and procedural outcomes of chronic total occlusions treated with percutaneous coronary interventions: analysis based on 14,899 patients.

BACKGROUND: Low operator and institutional volume is associated with poorer procedural and long-term clinical outcomes in patients treated with percutaneous coronary interventions (PCI). This study was aimed at evaluating the relationship between operator volume and procedural outcomes of patients treated with PCI for chronic total occlusion (CTO). METHODS: Data were obtained from the national registry of percutaneous coronary interventions (ORPKI) collected from January 2014 to December 2020. The primary endpoint was a procedural success, defined as restoration of thrombolysis in myocardial infarction (TIMI) II/III flow without in-hospital cardiac death and myocardial infarction, whereas secondary endpoints included periprocedural complications. RESULTS: Data of 14,899 CTO-PCIs were analyzed. The global procedural success was 66.1%. There was a direct relationship between the annual volume of CTO-PCIs per operator and the procedural success (OR: 1.006 [95% CI: 1.003-1.009]; P<0.001). The nonlinear relationships of annualized CTO-PCI volume per operator and adjusted outcome rates revealed that operators performing 40 CTO cases per year had the best procedural outcomes in terms of technical success (TIMI flow II/III after PCI), coronary artery perforation rate and any periprocedural complications rate (P<0.0001). Among the other factors associated with procedural success, the following can be noted: multi-vessel, left main coronary artery disease (as compared to single-vessel disease), the usage of rotablation as well as PCI within bifurcation. CONCLUSIONS: High-volume CTO operators achieve greater procedural success with a lower frequency of periprocedural complications. Higher annual caseload might increase the overall quality of CTO-PCI.

Single versus Dual-Operator Approaches for Percutaneous Coronary Interventions within Chronic Total Occlusion-An Analysis of 27,788 Patients.

(1) Background: Since the treatment of chronic total occlusion (CTO) with percutaneous coronary intervention (PCI) is associated with high procedural complexity, it has been suggested to use a multi-operator approach. This study was aimed at evaluating the procedural outcomes of single (SO) versus dual-operator (DO) CTO-PCI approaches. (2) Methods: This retrospective analysis included data from the Polish Registry of Invasive Cardiology Procedures (ORPKI), collected between January 2014 and December 2020. To compare the DO and SO approaches, propensity score matching was introduced with equalized baseline features. (3) Results: The DO approach was applied in 3604 (13%) out of 27,788 CTO-PCI cases. Patients undergoing DO CTO-PCI experienced puncture-site bleeding less often than the SO group (0.1% vs. 0.3%, p = 0.03). No differences were found in the technical success rate (successful revascularization with thrombolysis in myocardial infarction flow grade 2/3) of the SO (72.4%) versus the DO approach (71.2%). Moreover, the presence of either multi-vessel (MVD) or left main coronary artery disease (LMCA) (odds ratio (OR), 1.67 (95% confidence interval (CI), 1.20-2.32); p = 0.002), as well as lower annual and total operator volumes of PCI and CTO-PCI, could be noted as factors linked with the DO approach. (4) Conclusions: Due to the retrospective character, the findings of this study have to be considered only as hypothesis-generating. DO CTO-PCI was infrequent and was performed on patients who were more likely to have LMCA lesions or MVD. Operators collaboratively performing CTO-PCIs were more likely to have less experience. Puncture-site bleeding occurred less often in the dual-operator group; however, second-operator involvement had no impact on the technical success of the intervention.

Factors determining the frequency of optical coherence tomography and intravascular ultrasound use in patients treated with percutaneous coronary interventions in recent years: Analysis based on a large national registry.

BACKGROUND: Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have demonstrated improvement in the clinical outcome of patients undergoing percutaneous coronary intervention (PCI). AIMS: We aimed to examine the frequency of implementing OCT and IVUS during coronary angiography (CA) and PCI in everyday practice in Poland. Factors related to the more common choice of these imaging techniques were determined. METHODS: Data from the Polish National Registry of Percutaneous Coronary Interventions (ORPKI) were procured for analysis. Between January 2014 and December 2021, we extracted data on 1 452 135 CAs, 11 710 using IVUS (0.8%) and 1471 with OCT (0.1%) and 838 297 PCIs, 15 436 with IVUS (1.8%) and 1680 with OCT (0.2%). We assessed the determining factors for applying IVUS and OCT via multiple regression logistics models. RESULTS: The frequency of applying IVUS during CAs and PCIs increased significantly between the years 2014 and 2021. In 2021, it reached 1.54% for CAs and 4.42% for PCIs, while for OCT, there was a rise regarding the CA group, namely 0.13% in 2021, and, in the PCI group, 0.43%. Age was one of the factors significantly associated with the frequency of using IVUS/OCT during CA/PCI, which was confirmed by multivariate analysis (Odds ratio: 0.981 for IVUS and 0.973 for OCT use with PCI). CONCLUSION: The frequency at which IVUS and OCT were used has undergone a significant increase in previous years. This increase can be largely attributed to the current reimbursement policies. Further improvement is required for this frequency to be at a satisfactory level.

Gender differences in percutaneous coronary intervention for chronic total occlusions from the ERCTO study.

BACKGROUND: Gender-specific data addressing percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) in female patients are scarce and based on small sample size studies. AIMS: We aimed to analyze gender-differences regarding in-hospital clinical outcomes after CTO-PCI. METHODS: Data from 35,449 patients enrolled in the prospective European Registry of CTOs were analyzed. The primary outcome was the comparison of procedural success rate in the two cohorts (women vs. men), defined as a final residual stenosis less than 20%, with Thrombolysis In Myocardial Infarction grade flow = 3. In-hospital major adverse cardiac and cerebrovascular events (MACCEs) and procedural complications were deemed secondary outcomes. RESULTS: Women represented 15.2% of the entire study population. They were older and more likely to have hypertension, diabetes, and renal failure, with an overall lower J-CTO score. Women showed a higher procedural success rate (adjusted OR [aOR] = 1.115, confidence interval [CI]: 1.011-1.230, p = 0.030). Apart from previous myocardial infarction and surgical revascularization, no other significant gender differences were found among predictors of procedural success. Antegrade approach with true-to-true lumen techniques was more commonly used than retrograde approach in females. No gender differences were found regarding in-hospital MACCEs (0.9% vs. 0.9%, p = 0.766), although a higher rate of procedural complications was observed in women, such as coronary perforation (3.7% vs. 2.9%, p < 0.001) and vascular complications (1.0% vs. 0.6%, p < 0.001). CONCLUSIONS: Women are understudied in contemporary CTO-PCI practice. Female sex is associated with higher procedural success after CTO-PCI, yet no sex differences were found in terms of in-hospital MACCEs. Female sex was associated with a higher rate of procedural complications.

Contemporary issues of percutaneous coronary intervention in heavily calcified chronic total occlusions: an expert review from the European CTO Club.

Severe calcification is frequent in coronary chronic total occlusions (CTO), and its presence has been associated with increased procedural complexity and poor long-term outcomes following percutaneous coronary intervention (PCI) in an already challenging anatomical setting. The diagnostic characterisation of heavily calcified CTOs using non-invasive and invasive imaging tools can lead to the application of different therapeutic options during CTO PCI, in order to achieve adequate lesion preparation and optimal stent implantation. In this expert review, the European Chronic Total Occlusion Club provides a contemporary, methodological approach, specifically addressing heavily calcified CTOs, suggesting an integration of evidence-based diagnostic methods to tailored, up-to-date percutaneous therapeutic options.

Experience with Optical Coherence Tomography Enhanced by a Novel Software (Ultreon™ 1.0 Software)-The First One Hundred Cases.

Introduction: Optical coherence tomography (OCT) intravascular imaging including the latest version Ultreon™ 1.0 Software (Abbott Vascular, Santa Clara, CA, USA), not only improve patients prognosis, but also facilitates improved percutaneous coronary intervention (PCI). Objectives: The aim of the study was to compare procedure related decision making, procedural indices, clinical outcomes according to the extent of stent expansion and assess risk factors of underexpansion in patients treated with PCI using OCT. Methods: The study comprised 100 patients, which were divided in groups according to the extent of stent expansion: <90 (29 patients) and ≥90% (71 patients). Comparison of OCT parameters, selected clinical and procedural characteristics was performed between groups. We assessed clinical outcomes during the follow-up: major adverse cardiovascular events and risk factors of stent underexpansion. Results: Patients from the stent underexpansion group were treated more often in the past with percutaneous peripheral interventions (p=0.02), no other significant differences being noted in general characteristics, procedural characteristics or clinical outcomes comparing both groups. Significant predictors of stent underexpansion assessed by simple linear univariable analysis included: hypercholesterolemia, obstructive bronchial diseases and treatment with inhalators, family history of cardiovascular disease, PCI of other than the left main coronary artery, stent and drug-eluting stent implantation, PCI without drug-eluting balloon, paclitaxel antimitotic agent, greater maximal stent diameter and lower mean Euroscore II value. Univariable logistic regression analysis revealed a correlation between stent underexpansion and greater creatinine serum concentration before [OR: 0.97, 95%CI: 0.95-0.99, p=0.01] and after PCI [OR: 0.98, 95%CI: 0.96-0.99, p=0.02]. Conclusions: Based on the presented analysis, the degree of stent expansion is not related to the selected procedural, OCT imaging indices and clinical outcomes. Logistic regression analysis confirmed such a relationship for creatinine level.

Procedure-Related Differences and Clinical Outcomes in Patients Treated with Percutaneous Coronary Intervention Assisted by Optical Coherence Tomography between New and Earlier Generation Software (Ultreon™ 1.0 Software vs. AptiVue™ Software).

(1) Introduction: Optical coherence tomography (OCT) intravascular imaging facilitates percutaneous coronary intervention (PCI). Software for OCT is being constantly improved, including the latest version Ultreon™ 1.0 Software (U) (Abbott Vascular, Santa Clara, CA, USA). In the current analysis, we aim to compare processing results, procedural indices as well as clinical outcomes in patients treated via PCI. This was conducted using earlier generation OCT imaging software versions (non-U) and the newest available one on the market (U). (2) Methods: The study comprised 95 subsequent and not selected patients (55 processed with U and 40 non-U). The non-U processings were transferred for evaluation by U software, while the comparison of OCT parameters, selected clinical and procedural indices was performed between groups. We further assessed clinical outcomes during the follow-up period, i.e., major adverse cardiovascular events (MACE) and predictors of stent expansion. (3) Results: We did not detect any differences in general features between either of the assessed groups at baseline. Non-U software was more often used for bare-metal stenting (p = 0.004), while PCIs in the U group demanded a greater number of stents (p = 0.03). The distal reference of external elastic lamina (EEL) diameter was greater in the non-U group (p = 0.02) with no concurrent differences in minimal (p = 0.27) and maximal (p = 0.31) stent diameter. It was also observed that MACE was more frequently observed in the non-U group (p = 0.01). Neither univariable (estimate: 0.407, 95%CI: (-3.182) - 3.998, p = 0.82) nor multivariable (estimate: 2.29, 95%CI: (-4.207) - 8.788, p = 0.5) analyses demonstrated a relationship between the type of software and stent expansion. (4) Conclusions: Improvement in the software for image acquisition and processing of OCT is not related to stent expansion. The EEL diameter is preferably used to select the distal stent diameter in newer software.

Retrograde Chronic Total Occlusion Percutaneous Coronary Interventions: Predictors of Procedural Success From the ERCTO Registry.

OBJECTIVES: The aim of this study was to identify independent predictors of procedural success after retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: Retrograde CTO PCI is an established technique, but predictors of success remain poorly understood. METHODS: A multivariable logistic regression model was used to analyze potentially important demographic, clinical, anatomical, and technical aspects of retrograde CTO PCI cases uploaded to the multicenter European CTO (ERCTO) Club Registry. RESULTS: In calendar years 2018 and 2019, 2,364 retrograde CTO PCI cases constituted the primary analysis cohort. A primary retrograde strategy was used in 1,953 cases (82.6%), and an initial antegrade approach was converted to retrograde in 411 cases (17.4%). Procedural success was achieved in 1,820 cases (77.0%) and was more likely to occur after a primary retrograde attempt versus conversion from an initial antegrade approach (80.9% vs 58.4%; P < 0.0001). After multivariable analysis, an absence of lesion calcification (OR: 1.86; 95% CI: 1.37-2.51; P < 0.0001), a higher degree of distal vessel opacification (OR: 2.47; 95% CI: 1.72-3.55; P < 0.0001), little or no proximal target vessel tortuosity (OR: 1.84; 95% CI: 1.28-2.64; P = 0.001), Werner collateral connection CC1 (OR: 4.87; 95% CI: 2.90-8.19; P < 0.0001) or CC2 (OR: 5.33; 95% CI: 3.02-9.42; P < 0.0001), and the top tertile of operator volume (>120 cases over 2 years) (OR: 1.88; 95% CI: 1.26-2.79; P = 0.002) were associated with the greatest chance of achieving angiographic success. CONCLUSIONS: Less calcification with good distal vessel opacification, little or absent proximal vessel tortuosity, and visible collateral connections, along with high-volume operator status, were all independently predictive of angiographically successful retrograde CTO PCI.

Procedural Outcomes in Patients Treated with Percutaneous Coronary Interventions within Chronic Total Occlusions Stratified by Gender.

It has been demonstrated that gender differences are related to different procedural and long-term clinical outcomes among a general patient population treated using percutaneous coronary interventions (PCI). The objective of our analysis was to conduct assessment regarding the relationship between gender and procedural outcomes in patients treated for PCI regarding chronic total occlusions (CTO), based on a large, real-life registry. Data used to conduct the following analysis was derived from the national registry of percutaneous coronary interventions (ORPKI), upheld in co-operation with the Association of Cardiovascular Interventions (AISN) of the Polish Cardiac Society. The study involved data procured from the registry within the period from January 2014 to December 2020. All subsequent CTO procedures recorded in the registry during that period were included in the analysis. We assessed the correlation between gender and the overall rate of periprocedural complications, procedure-related mortality, and success evaluated as TIMI flow grade 3 after the procedure by univariate and multivariable modeling. At the time of conducting our investigation, there were 162 existing and active CathLabs, at which 747,033 PCI procedures were carried out during the observational period. Of those, 14,903 (1.99%) were CTO-PCI procedures, and 3726 were women (25%). The percentage share between genders did not experience any significant changes during the consecutive years observed in the current analysis. Overall periprocedural complication rate was greater among women than men (3.45% vs. 2.31%, p = 0.02). A comparable relationship was noted for procedural mortality (0.7% vs. 0.2%, p = 0.006), while procedural success occurred more often in the case of women (69.3% vs. 65.2%, p < 0.001). Women were found to be more frequently affected by periprocedural complications (OR = 1.553; 95%CI: 1.212−1.99, p < 0.001) as well as procedural success (OR = 1.294; 95%CI: 1.151−1.454, p < 0.001), evaluated using multivariable models. Based on the current analysis performed on all-comer patients treated using PCI in CTO, women are affected by more frequent procedural complication occurrence as well as greater procedural success compared to men.

Predictors and trends of contrast use and radiation exposure in a large cohort of patients treated with percutaneous coronary interventions: Chronic total occlusion analysis based on a national registry.

BACKGROUND: The aim herein, was to assess predictors and current trends of radiation exposure and total contrast amount use in patients treated with percutaneous coronary intervention within chronic total occlusion (CTO PCI) and non-CTO PCI. METHODS: Based on a nationwide registry (ORPKI), 535,857 patients treated with PCI between 2014 and 2018 were analysed. The study included 12,572 (2.34%) patients treated with CTO PCI. The CTO PCI and non-CTO PCI groups were compared before and after propensity score matching (PSM). Multifactorial mixed regression models were used to assess predictors of contrast amount use and radiation exposure. RESULTS: The mean total contrast dose and radiation exposure decrease reached statistical significance in following years for the CTO PCI (p = 0.002 and p < 0.001) and non-CTO PCI groups (p < 0.001 and p < 0.001). Multifactorial analysis revealed that non-CTO PCI was a strong independent predictor of lower total contrast dose (estimate: -17.41; 95% confidence interval [CI]: -18.45 to -16.49, p < 0.001) and radiation exposure (estimate: -264.28; 95% CI: -273.75 to -254.81, p < 0.001). After PSM, it was confirmed that CTO PCI was an independent predictor of greater radiation exposure (estimate: 328.6; 95% CI: 289.1-368.1; p < 0.001) and total contrast dose (estimate: 30.5; 95% CI: 27.28-33.74; p < 0.001). CONCLUSIONS: Contrast dose and radiation exposure have decreased in previous years with regard to the CTO PCI and non-CTO PCI groups. CTO PCI was found to be an independent predictor of greater total contrast dose and radiation exposure in the overall group of patients treated with PCI.

Global Chronic Total Occlusion Crossing Algorithm: JACC State-of-the-Art Review.

The authors developed a global chronic total occlusion crossing algorithm following 10 steps: 1) dual angiography; 2) careful angiographic review focusing on proximal cap morphology, occlusion segment, distal vessel quality, and collateral circulation; 3) approaching proximal cap ambiguity using intravascular ultrasound, retrograde, and move-the-cap techniques; 4) approaching poor distal vessel quality using the retrograde approach and bifurcation at the distal cap by use of a dual-lumen catheter and intravascular ultrasound; 5) feasibility of retrograde crossing through grafts and septal and epicardial collateral vessels; 6) antegrade wiring strategies; 7) retrograde approach; 8) changing strategy when failing to achieve progress; 9) considering performing an investment procedure if crossing attempts fail; and 10) stopping when reaching high radiation or contrast dose or in case of long procedural time, occurrence of a serious complication, operator and patient fatigue, or lack of expertise or equipment. This algorithm can improve outcomes and expand discussion, research, and collaboration.

Dual lumen microcatheters for recanalisation of chronic total occlusions: a EuroCTO Club expert panel report.

Dual lumen microcatheters (DLMC) have become indispensable tools in the setting of percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). Other than allowing preservation and treatment of bifurcated coronary branches within or in the proximity of the CTO body, they enable the use of modified parallel wiring, antegrade dissection and re-entry, collateral selection and retrograde negotiation of the distal CTO cap. This EuroCTO consensus document describes current DLMC and suggests a practical guide to anatomies and techniques in which these devices are applicable.

OCT Findings in MINOCA.

Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is a working diagnosis for patients presenting with acute myocardial infarction without obstructive coronary artery disease on coronary angiography. It is a heterogenous entity with a number of possible etiologies that can be determined through the use of appropriate diagnostic algorithms. Common causes of a MINOCA may include plaque disruption, spontaneous coronary artery dissection, coronary artery spasm, and coronary thromboembolism. Optical coherence tomography (OCT) is an intravascular imaging modality which allows the differentiation of coronary tissue morphological characteristics including the identification of thin cap fibroatheroma and the differentiation between plaque rupture or erosion, due to its high resolution. In this narrative review we will discuss the role of OCT in patients presenting with MINOCA. In this group of patients OCT has been shown to reveal abnormal findings in almost half of the cases. Moreover, combining OCT with cardiac magnetic resonance (CMR) was shown to allow the identification of most of the underlying mechanisms of MINOCA. Hence, it is recommended that both OCT and CMR can be used in patients with a working diagnosis of MINOCA. Well-designed prospective studies are needed in order to gain a better understanding of this condition and to provide optimal management while reducing morbidity and mortality in that subset patients.

Chronic total occlusion percutaneous coronary intervention in everyday clinical practice - an expert opinion of the Association of Cardiovascular Interventions of the Polish Cardiac Society.

Coronary chronic total occlusions (CTO) are increasingly encountered during invasive and non-invasive coronary angiography and remain the most challenging lesions for percutaneous revascularization. During recent years success rates and safety outcomes of CTO percutaneous coronary intervention (PCI) have substantially improved, particularly due to the introduction of new techniques and dedicated equipment as well as specialized training programs of CTO operators. Significantly, the steady advances in CTO PCI techniques have coincided with the new data from randomized clinical trials supporting the role of percutaneous recanalization of CTO in relieving angina and improving the quality of life. The current expert consensus document outlines the rationale, clinical outcomes as well as technical, safety and reimbursement issues of CTO PCI. In addition, the requirements for achieving and maintaining competency in CTO PCI among interventional cardiologists are discussed. Finally, we present the modified hybrid algorithm (the so-called Polish hybrid algorithm) providing some unique refinements to the contemporary CTO PCI strategies. Continuous efforts (including active engagement with the payer) are urgently needed to increase guideline-recommended referrals to CTO PCI, and thus improve the quality of life of CTO patients in Poland.

Radiation Exposure for Percutaneous Interventions of Chronic Total Coronary Occlusions in a Multicenter Registry: The Influence of Operator Variability and Technical Set-up.

AIMS: Radiation exposure is a limiting factor for percutaneous coronary interventions (PCI) of chronic total coronary occlusion (CTO) lesions. This study was designed to analyze changes in patient radiation dose for CTO-PCI and parameters associated with radiation dose. METHODS AND RESULTS: We analyzed a cohort of 12,136 procedures performed by 23 operators between 2012 and 2017 from the European Registry of CTO-PCI. Radiation exposure was recorded as air kerma (AK) and dose area product (DAP). A dose rate index (DRI) was calculated as AK per fluoroscopy time to normalize for individual differences in fluoroscopy time. The lesion complexity increased from Japanese-CTO (J-CTO) score of 2.19 ± 1.44 to 2.46 ± 1.28, with an increase of retrograde procedures from 31.1% to 40.7%; still, procedural success improved from 87.7% to 92.1%. Fluoroscopy time remained similar, but AK decreased by 14.9%, from 2.35 Gy (interquartile range [IQR], 1.29-4.14 Gy) to 2.00 Gy (IQR, 1.08-3.45 Gy) and DAP decreased by 21.5%, from 130 Gy•cm² (IQR, 70-241 Gy•cm²) to 102 Gy•cm² (IQR, 58-184 Gy•cm²). Radiation exposure was determined by the lesion complexity (J-CTO score) and procedural complexity (antegrade or retrograde). DRI was determined by fluoroscopy frame rate and type of equipment used, but the major influence remained interoperator differences. CONCLUSIONS: Radiation exposure decreased during the observation period despite an increase in lesion and procedural complexity. While many operators already achieved a goal of low radiation exposure, there were considerable interoperator differences in radiation management, indicating further potential for improvement.

Safety and efficacy of the NovaCross microcatheter in facilitating crossing of chronic total occlusion coronary lesions: a multicenter, single-arm clinical trial.

BACKGROUND: The aim of this study was to evaluate the safety and efficacy of the novel NovaCross microcatheter system in patients with ischemic heart disease due to coronary chronic total occlusions (CTO). METHODS: A total of 191 subjects between the ages of 25-80 years were recruited in 10 investigational sites. Each subject underwent a percutaneous coronary intervention (PCI) of a CTO lesion using the NovaCross microcatheter, equipped with expandable nitinol scaffolds to enhance guidewire penetration and crossing of the CTO lesion. The primary safety endpoint was procedural major adverse cardiac events [composite of death, myocardial infarction (MI), or urgent target vessel revascularization]. The primary efficacy endpoint was to assess the ability of the NovaCross microcatheter to successfully facilitate the placement of a guidewire beyond a native coronary CTO in the true vessel lumen. After the PCI, subjects remained in hospital until a 12-lead ECG and blood tests for cardiac biomarkers were taken at 3-6 h and 8-16 h post-procedure. RESULTS: No deaths, urgent revascularization, or urgent coronary artery bypass surgery were reported. The reported MI rate according to the protocol definition was 12.3%, and technical success was achieved in 75.3% of the subjects regardless of CTO procedure technique. In 89.2% of the subjects, the NovaCross succeeded in penetrating the proximal CTO cap, and in 25.8% of the subjects, the extendable portion of the NovaCross crossed the full length of the CTO lesion. CONCLUSIONS: The NovaCross met both the primary safety endpoint and the primary efficacy endpoint. We, therefore, conclude that the device is well tolerated, effective, and could be easily adopted by interventional cardiologists.