Chronic Total Occlusions: A State-of-the-Art Review.

The percutaneous management of chronic total occlusions (CTO) is a well-established sub-specialty of Interventional Cardiology, requiring specialist equipment, training, and techniques. The heterogeneity of approaches in CTO has led to the generation of multiple algorithms to guide operators in their management. The evidence base for management of CTOs has suffered from inconsistent descriptive and quantitative terminology in defining the nature of lesions and techniques utilised, as well as seemingly contradictory data about improvement in ventricular function, symptoms of angina, and mortality from large-scale registries and randomised controlled trials. Through this review, we explore the history of CTO management and its supporting evidence in detail, with an outline of limitations of CTO-percutaneous coronary intervention and a look at the future of this growing field within cardiology.

Coronary "Microvascular Dysfunction": Evolving Understanding of Pathophysiology, Clinical Implications, and Potential Therapeutics.

Until recently, it has been generally held that stable angina pectoris (SAP) primarily reflects the presence of epicardial coronary artery stenoses due to atheromatous plaque(s), while acute myocardial infarction (AMI) results from thrombus formation on ruptured plaques. This concept is now challenged, especially by results of the ORBITA and ISCHEMIA trials, which showed that angioplasty/stenting does not substantially relieve SAP symptoms or prevent AMI or death in such patients. These disappointing outcomes serve to redirect attention towards anomalies of small coronary physiology. Recent studies suggest that coronary microvasculature is often both structurally and physiologically abnormal irrespective of the presence or absence of large coronary artery stenoses. Structural remodelling of the coronary microvasculature appears to be induced primarily by inflammation initiated by mast cell, platelet, and neutrophil activation, leading to erosion of the endothelial glycocalyx. This leads to the disruption of laminar flow and the facilitation of endothelial platelet interaction. Glycocalyx shedding has been implicated in the pathophysiology of coronary artery spasm, cardiovascular ageing, AMI, and viral vasculitis. Physiological dysfunction is closely linked to structural remodelling and occurs in most patients with myocardial ischemia, irrespective of the presence or absence of large-vessel stenoses. Dysfunction includes the impairment of platelet and vascular responsiveness to autocidal coronary vasodilators, such as nitric oxide, prostacyclin, and hydrogen sulphide, and predisposes both to coronary vasoconstriction and to a propensity for microthrombus formation. These findings emphasise the need for new directions in medical therapeutics for patients with SAP, as well as a wide range of other cardiovascular disorders.

Assessing the Impact of Colchicine on Coronary Plaque Phenotype After Myocardial Infarction with Optical Coherence Tomography: Rationale and Design of the COCOMO-ACS Study.

INTRODUCTION: Recurrent event rates after myocardial infarction (MI) remain unacceptably high, in part because of the continued growth and destabilization of residual coronary atherosclerotic plaques, which may occur despite lipid-lowering therapy. Inflammation is an important contributor to this ongoing risk. Recent studies have shown that the broad-acting anti-inflammatory agent, colchicine, may reduce adverse cardiovascular events in patients post-MI, although the mechanistic basis for this remains unclear. Advances in endovascular arterial wall imaging have allowed detailed characterization of the burden and compositional phenotype of coronary plaque, along with its natural history and responsiveness to treatment. One such example has been the use of optical coherence tomography (OCT) to demonstrate the plaque-stabilizing effects of statins on both fibrous cap thickness and the size of lipid pools within plaque. METHODS: The Phase 2, multi-centre, double-blind colchicine for coronary plaque modification in acute coronary syndrome (COCOMO-ACS) study will evaluate the effect of colchicine 0.5 mg daily on coronary plaque features using serial OCT imaging in patients following MI. Recruitment for the trial has been completed with 64 participants with non-ST elevation MI randomized 1:1 to colchicine or placebo in addition to guideline recommended therapies, including high-intensity statins. The primary endpoint is the effect of colchicine on the minimal fibrous cap thickness of non-culprit plaque over an 18-month period. The COCOMO-ACS study will determine whether addition of colchicine 0.5 mg daily to standard post-MI treatment has incremental benefits on high-risk features of coronary artery plaques. If confirmed, this will provide new mechanistic insights into how colchicine may confer clinical benefits in patients with atherosclerotic cardiovascular disease. TRIAL REGISTRATION: ANZCTR trial registration number: ACTRN12618000809235. Date of trial registration: 11th of May 2018.

Impact of Patient BMI on Patient and Operator Radiation Dose During Percutaneous Coronary Intervention.

AIMS: This study sought to investigate patient and operator radiation dose in patients undergoing percutaneous coronary intervention (PCI) and the impact of body mass index (BMI) on patient and operator dose. METHODS: In patients undergoing PCI, radiation dose parameters, baseline characteristics and procedural data were collected in a tertiary centre for 3.5 years. Operators wore real time dosimeters. Patients were grouped by BMI. Dose area product (DAP) and operator radiation dose were compared across patient BMI categories. Multivariable analysis was performed to investigate the impact of patient BMI and other procedural variables on patient and operator dose. RESULTS: 2,043 patients underwent 2,197 PCI procedures. Each five-unit increase in BMI increased patient dose (expressed as DAP) by an average 31% (95% CI: 29-33%) and operator dose by 27% (95% CI: 20-33%). Patient dose was 2.3 times higher and operator dose was 2.4 times higher in patients with a BMI>40 than for normal BMI patients. Multivariable analysis indicated that there were many procedural factors that were predictors for increasing operator dose and patient dose but that patient BMI was a major contributor for both operator dose and patient dose. CONCLUSION: Increasing BMI increases the DAP and operator dose for PCI procedures and BMI is demonstrated to be a major factor that contributes to both patient and operator radiation dose.

An ultra-low-profile 0.85 mm Nano Hydro balloon to treat wire-crossable balloon-uncrossable lesions: A useful tool in CTO armamentarium.

Balloon uncrossable lesions are commonly encountered during chronic total occlusion (CTO) percutaneous coronary intervention (PCI). A sequential strategy and planning are required to tackle such lesions. We present a case series of severely calcified, device uncrossable lesions where the traditional strategies failed and an ultra-low-profile (0.85 mm) balloon was crucial to successful PCI. To our best knowledge, this is the first case series describing the use of this balloon in real world.

Treatment of rotablation-induced ostial left circumflex perforation by papyrus covered stent and its fenestration to recover the left anterior descending artery during CHIP procedure.

Coronary artery perforation is a rare complication of percutaneous coronary intervention (PCI). Covered stents have been successfully used in these situations. We report a case of ostial left circumflex (LCx) artery perforation during rotablation PCI of left main coronary artery (LMCA) and LCx artery. After failed attempts to balloon tamponade the perforation, a PK Papyrus covered stent was deployed from proximal LCx into LMCA. This resulted in acute exclusion of the left anterior descending (LAD) artery from coronary circulation. Using a dual lumen catheter, a stiff wire was advanced through the side port toward the occluded LAD to fenestrate the membrane of the covered stent. A series of balloons were used to dilate the fenestration in the covered stent to restore a normal flow into the LAD.

Incidence, predictors and longer-term impact of troponin elevation following hybrid chronic total occlusion percutaneous coronary intervention.

OBJECTIVES: We examined the incidence of periprocedural cardiac enzyme rise (PCER) [troponin T (TnT) or high-sensivity (hs)TnT >5× the upper limit of normal (ULN)] and periprocedural myocardial infarction (PMI), predictors of PCER and impact of PCER on the longer-term major adverse cardiac events (MACE) following hybrid chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: PCER and PMI after CTO PCI, risk factors for PCER and its impact on longer-term MACE are not fully understood. METHODS: Among 469 CTO PCI cases performed between 01/2010 and 12/2015, next-day TnT or hsTnT was measured in 455 (97%). We examined the incidence of PCER and PMI (with clinical context or TnT ≥70× ULN). In 269 successful cases who had TnT measured, longer-term MACE (death, MI or target-vessel revascularisation/re-occlusion) were assessed. RESULTS: Overall, 420 CTOs (92.3%) were treated successfully. PCER was documented in 34%, while PMI in 2.9%. By multivariable analyses, higher J-CTO score (OR = 1.3 per point; P = 0.002), lower creatinine clearance (OR = 1.01 per each cc/min decrease; P < 0.0001) and recent MI (OR = 2.4; P = 0.007) were independent pre-PCI risk factors for PCER. Among procedural variables, retrograde approach (OR = 1.9; P = 0.014) and procedure duration (OR = 1.2 per 30 min; P = 0.007) were associated with PCER. At a median follow-up of 396 days following successful CTO PCI, PCER was not associated with higher MACE (9.3% vs. 8.1%; P = 0.60), and was not a predictor of MACE in multivariable analysis. CONCLUSIONS: PCER following hybrid CTO PCI is detected in 1/3 of patients. However, true PMI occurs in 2.9%. PCER does not predict adverse long-term outcomes.

Stent luxation: Possible complication of subadventitial stenting in coronary chronic total occlusion revascularization.

The entry to the subadventitial space is not a mode of failure, but the road to success in many chronic total occlusion (CTO) percutaneous coronary intervention (PCI) cases. Long-term clinical outcomes of subadventitial stenting are favorable and similar to intraluminal stenting. However, the subadventitial space histology and physiology remains different to the coronary true intraluminal space. We report a complication specific to stenting of the subadventitial space, where overlapping stents dislocated from one another, which resulted in late non-occlusive stent thrombosis. We describe, for the first time in the literature, this complication, possible reasons behind, and the ways to avoid this potentially major mischief. © 2016 Wiley Periodicals, Inc.

Long-term outcomes of rotational atherectomy for the percutaneous treatment of chronic total occlusions.

OBJECTIVES: To study the long-term outcomes of rotational atherectomy (RA) for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). BACKGROUND: There is little evidence on the incidence, procedural results and long-term outcomes of RA for CTO PCI. METHODS: This registry included data from consecutive patients undergoing CTO PCI at four specialized centers. Major adverse cardiac events (MACE: cardiac death, target-vessel myocardial infarction and ischemia-driven target-vessel revascularization) on follow-up were the primary endpoint. RESULTS: A total of 1003 patients were included. Of these, 35 (3.5%) required RA. As compared with Conventional PCI, RA patients were older (68.9 ± 9.5 vs. 64.6 ± 10.7 years, P = 0.02), had higher prevalence of diabetes (58% vs. 37%, P = 0.01) and of a J-CTO score ≥2 (80% vs. 58%, P = 0.009), driven by severe calcification. Antegrade wire escalation was used more frequently in RA (74% vs. 53%, P = 0.08). RA was performed for balloon failure-to-cross in 51% and failure-to-expand in 49%. One burr was utilized in 86%. The 1.25-mm burr was the largest burr used in 43%. Slow flow/no-reflow was observed in 17%. No other serious RA-related complications were observed. Procedural success was 77% vs. 89% (P = 0.04) in RA vs. Conventional PCI. After a mean follow-up of 658 ± 412 days, MACE rates were similar between groups (15% vs. 13%, P = 0.70). CONCLUSIONS: The use of RA in CTO PCI was safe, despite a worse patient risk profile and higher procedural complexity, as compared with conventional techniques. Although procedural success was lower in the RA group, there were no differences in long-term clinical outcomes between groups. © 2016 Wiley Periodicals, Inc.

Stumpless chronic total occlusion with no retrograde option: Multidetector computed tomography-guided intervention via bi-radial approach utilizing bioresorbable vascular scaffold.

When dealing with flush ostial chronic total occlusion (CTO) and no viable retrograde option, the only way to perform recanalization is through an antegrade approach. Such a procedure can be extremely difficult considering the ambiguity of the proximal cap. We demonstrate how we solved ambiguity of the proximal cap of an ostial obtuse marginal CTO with the help of cardiac multidetector computed tomography (MDCT). We also discuss several techniques including bilateral radial approach with home-made sheathless large-bore catheters, IVUS-guided cap puncture, ping-pong guide catheters engagement in the left main, and bioresorbable vascular scaffold (BVS) for an ostial left circumflex disease that we all used in our CTO case.

Hypoxic potentiation of nitrite effects in human vessels and platelets.

Previous studies in non-human blood vessels and in platelets have demonstrated that under hypoxic conditions release of NO from nitrite (NO2(-)) is potentiated by deoxyhaemoglobin. In the current study, we characterized hypoxic potentiation of NO2(-) effects in human vasculature and platelets in vitro, addressing underlying mechanisms. The vasodilator efficacy of NO2(-), in comparison with glyceryl trinitrate (GTN), was evaluated in vitro, using segments of human saphenous vein. Under hypoxic conditions, there was a leftward shift of the NO2(-) concentration-response curve (EC50: 22 µM in hyperoxia vs 3.5 µM in hypoxia; p<0.01), but no significant potentiation of GTN effect. In the presence of red blood cells, hypoxic potentiation of NO2(-) vasodilator effect was accentuated. In whole blood samples and platelet-rich plasma (PRP) we assessed inhibition of platelet aggregation by NO2(-) (1mM), in comparison with that of sodium nitroprusside (SNP, 10 µM). In individual subjects (n=37), there was a strong correlation (r=0.75, p<0.0001) between anti-aggregatory effects of NO2(-) and SNP in whole blood, signifying that resultant sGC activation underlies biological effect and responses to NO2(-) are diminished in the presence of NO resistance. In PRP, the effects of NO2(-) were less pronounced than in whole blood (p=0.0001), suggesting an important role of Hb (within RBCs) in the bioconversion of NO2(-) to NO. Inhibition of platelet aggregation by NO2(-) was almost 3-fold greater in venous than in arterial blood (p<0.0001), and deoxyHb concentration directly correlated (r=0.69, p=0.013) with anti-aggregatory response. Incremental hypoxia applied to venous blood samples (in hypoxic chamber) caused a progressive increase in both deoxyHb level and anti-aggregatory effect of NO2(-). When subjects inhaled a 12% O2 mixture for 20 min, there was a 3-fold rise in blood deoxyHb fraction (p<0.01). In PRP, response to NO2(-) also increased under hypoxia, and was further enhanced (p<0.01) by deoxyHb. Furthermore, deoxyHb exerted significant anti-aggregatory effects even in the absence of added NO2(-), suggesting a role for endogenous NO2(-). The results of this work provide further mechanistic insights into hypoxic potentiation of vasodilator and anti-aggregatory actions of NO2(-). In human saphenous veins and blood, the balance of evidence suggests differential rates of NO release from NO2(-) (largely modulated by deoxyHb) as the fundamental mechanism.

Investigation of scatter radiation intensities in the cardiac catheter laboratory: novel versus traditional shielding solutions.

A manufacturer has released a novel shielding solution (NSS): Rampart M1128 and claimed that the personal protective equipment (PPE) can be removed. This study investigates the scatter intensities with the NSS or the traditional shielding solutions (TSS) including the ceiling-suspended screen and the tableside lead drape. Isodose maps were generated by two series of measurements with an anthropomorphic phantom using NSS and TSS. Three survey meters were positioned at different heights to measure the scatter intensities at the eye, chest, and pelvic levels. Additional measurements were made at the primary and secondary operators? locations to evaluate the scatter intensities with different clinical projections. For the main operator positions, the isodose maps showed that NSS could result in a scatter dose that reduced by 80% to 95% compared to the same positions with TSS at the eye and chest levels. The corresponding result at the pelvic level was a reduction of 50%. These reductions should be compared to the additional protection by PPE: up to 80% reduction from lead eyeglasses and up to 95% from protective garments. Considering both operators at clinically relevant LAO projections, NSS resulted in scatter dose that was 80% to 96%, 76% to 96% and 25% to 60% lower than those of the TSS at eye, chest and pelvis levels. The protection of NSS is comparable with that of TSS alongside PPE at the eye but not at the chest and the pelvic levels under the setup of coronary angiography.

Trial of a Novel Radiation Shielding Device to Protect Staff in the Cardiac Catheter Laboratory.

Continuous exposure to low-level scattered radiation to staff performing cardiac angiography and intervention is of concern. A novel shielding solution (NSS) (Rampart IC M1128) has the potential to provide greater shielding for staff present at the table-side. This study aimed to investigate the effectiveness of the NSS compared with a traditional shielding solution (TSS) in a randomized controlled trial that enrolled 100 patients who underwent cardiac angiography and/or intervention which were randomized to the NSS or TSS. Baseline patient characteristics and radiation dose data were collected. Staff who were scrubbed at the table-side wore 5 real-time dosimeters on the head, collar, waist, ankle, and under the apron. The median primary operator radiation dose was significantly lower (p <0.001) for all dosimeter locations with the NSS when compared with the TSS, being reduced by 86%, 80.0%, 100%, and 50.0% for the head, collar, waist, and leg respectively. Median under-apron dose was 0.0 µSv for both NSS and TSS. Median second operator dose was reduced by 100%, 100%, and 100% for the head, collar, and waist respectively (p <0.001). Median NSS and TSS dose at the ankle and under apron was 0.0 µSv. Median scrub nurse dose was reduced by 50% and 100% for the head and collar respectively (p <0.001). Median NSS and TSS dose at the waist, ankle, and under apron was 0.0 µSv. In conclusion, the NSS tested in this study demonstrates a significant decrease in radiation dose to operators and scrub nurses when compared with traditional radiation protection measures.

Primary operator radiation dose in the cardiac catheter laboratory.

OBJECTIVES: Radiation from cardiac angiography procedures is harmful to patients and the staff performing them. This study sought to investigate operator radiation dose for a range of procedures and different operators in order to investigate trends and optimise dose. METHODS: Real-time dosemeters (RTDs) were worn by operators for angiography procedures for 3 years. Dose-area product (DAP) and RTD were collected. RTD was normalised to DAP (RTD/DAP) to compare radiation dose and radiation protection measures. Comparisons were made across procedure categories and individual operators. RESULTS: In 7626 procedures, median and 75th percentile levels were established for operator dose for 8 procedure categories. There was a significant difference in all operator dose measures and DAP across procedure categories (p<0.001). DAP, RTD, and RTD/DAP were significantly different across 22 individual operators (p<0.001). CONCLUSION: DAP was significantly different across procedure categories and a higher RTD was seen with higher DAP. RTD/DAP can demonstrate radiation protection effectiveness and identified differences between procedures and individual operators with this measure. Procedures and individuals were identified where further optimisation of radiation protection measures may be beneficial. A reference level for operator dose can be created and audited against on a regular basis. ADVANCES IN KNOWLEDGE: This study demonstrates that operator dose can be easily and routinely measured on a case by case basis to investigate dose trends for different procedures. Normalising the operator dose to DAP demonstrates radiation protection effectiveness for the individual operator which can then be optimised as part of an ongoing audit program.

Long-Term Outcomes of Percutaneous Coronary Intervention for Chronic Total Occlusion in Patients Who Have Undergone Coronary Artery Bypass Grafting vs Those Who Have Not.

BACKGROUND: We aimed to investigate the procedural and long-term outcomes of percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) in patients who had undergone previous coronary artery bypass grafting (CABG) vs those who had not, and to evaluate the role of the Registry of CrossBoss and Hybrid procedures in France, the Netherlands, Belgium, and United Kingdom (RECHARGE) score in predicting acute and long-term outcomes. METHODS: We compiled a multicentre registry of consecutive patients undergoing CTO PCI at 7 centres between January 2009 and April 2017. The primary end point was target-vessel failure (TVF), a composite of cardiac death, target-vessel myocardial infarction, and target-vessel revascularization on follow-up. RESULTS: Overall, 2058 patients were included (patients who underwent CABG, n = 401; CABG-naïve patients, n = 1657). Patients who had undergone CABG were older and had a higher prevalence of comorbidities and higher occlusion complexity (RECHARGE score, 3.6 ± 1.3 vs 1.8 ± 1.2; P < 0.001). Antegrade dissection/re-entry techniques and the retrograde approach were used more frequently in patients who had undergone CABG. Procedural metrics were worse, and technical (82% vs 88%; P = 0.001) and procedural (81% vs 87%; P = 0.001) success was lower in patients who had undergone CABG. They also experienced a higher rate of major complications (3.7% vs 1.5%; P = 0.004). The RECHARGE score was inversely associated with technical success (P < 0.001). Median follow-up was 377 days (interquartile range, 277-766 days). The 24-month TVF rate was higher in patients who had undergone CABG than in CABG-naïve patients (16.1% vs 9.0%; P < 0.001). On multivariable analysis, the RECHARGE score (hazard ratio, 1.61; P < 0.001) remained an independent predictor of TVF, together with longer total stent length and not using a drug-eluting stent. CONCLUSIONS: Compared with CABG-naïve patients, CTO PCI in patients who had undergone CABG shows higher procedural complexity, worse success rates, and higher adjusted risk of TVF on follow-up.

Midterm Angina-Related Quality of Life Benefits After Percutaneous Coronary Intervention of Chronic Total Occlusions.

BACKGROUND: Data on the impact of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) on quality of life (QOL) are limited. To date, studies have been limited in sample size and have focused on only a few domains of the Seattle Angina Questionnaire (SAQ). We evaluated the relationship between coronary CTO PCI and QOL in patients with symptoms of angina, incorporating all aspects of the SAQ. METHODS: The SAQ was used to interrogate patients at baseline and at 12 months after CTO PCI. The primary end point was improvement in SAQ scores. RESULTS: A total of 184 patients answered the baseline SAQ. One hundred twenty-two patients answered both questionnaires. SAQ responders were more likely to be men, more like to be in stable medical condition, and more likely to have undergone a successful procedure. We observed statistically significant improvement (P < 0.0001) in physical limitation (mean difference [MD], +27; 95% confidence interval [CI], +23 to +32), angina stability (MD, +16; 95% CI, +10 to +21), angina frequency (MD, +27; 95% CI, +22 to +32), treatment satisfaction (MD, +10; 95% CI, +6 to +13), and QOL domains (MD, +28; 95% CI, +24 to +32). Patients with coronary artery bypass grafting, dissection re-entry techniques, and high complexity (Japanese CTO [J-CTO] ≥ 3) had a similar degree of improvement when compared with their counterparts. CONCLUSIONS: CTO PCI is associated with a significant improvement in QOL at 12 months. Patients with complex CTOs derive benefits similar to those in patients with less complex CTOs.

Safety and effectiveness of the surfing technique to cross septal collateral channels during retrograde chronic total occlusion percutaneous coronary intervention.

AIMS: Septal surfing and distal tip injections are two techniques used for septal crossing in retrograde chronic total occlusion (CTO) percutaneous coronary interventions (PCI). The aim of this study was to examine for the first time the safety and feasibility of the septal surfing technique. METHODS AND RESULTS: Among 470 consecutive CTO PCIs performed in the Quebec hybrid CTO PCI program between January 2010 and December 2015, 240 (51%) involved a retrograde attempt. In the septal crossing subgroup, we evaluated whether the Werner collateral channel (CC) classification, CTO location, tortuosity, and number of large septal CCs influenced retrograde crossing success, time, and perforation. Septal channels were used in the majority (n=152, 63%) of cases. Patients in the septal subgroup were younger, had less bypass surgery, were more likely to have RCA CTO and had previous failure. Septal channels were successfully crossed with the wire using the surfing technique in 81%, irrespective of the CC size. Septal crossing success and time were not influenced by Werner CC class but by septal CC tortuosity. One quarter of cases had septal perforations; all were minor and asymptomatic. CONCLUSIONS: Septal surfing is a safe and highly successful technique for crossing septal CCs when a retrograde approach is mandated for CTO PCI. The Werner class does not affect retrograde CC crossing success or time.

Impact of crossing strategy on midterm outcomes following percutaneous revascularisation of coronary chronic total occlusions.

AIMS: The aim of the present study was to compare the midterm clinical outcomes of patients undergoing successful chronic total occlusion (CTO) percutaneous coronary intervention (PCI) according to the crossing technique used, in a large multicentre registry. METHODS AND RESULTS: We compiled a multicentre registry of consecutive patients undergoing successful CTO PCI. Patients were divided into three groups: true-to-true (TTT) approach, modern dissection/re-entry (DR) techniques (CrossBoss/Stingray, reverse CART), and old DR techniques (LAST, STAR, CART). Cox regression was used to identify independent predictors of major adverse cardiac events (MACE: cardiac death, myocardial infarction and target vessel revascularisation). We included 924 patients (TTT, n=571; modern DR, n=258; old DR, n=95). Patients in both DR groups had a higher prevalence of comorbidities, angiographic and procedural complexity. The 12-month MACE rate was higher in old DR (22.1%) than in modern DR (8.9%) and TTT (9.1%, p<0.001). Old (hazard ratio [HR] 2.02, 95% confidence interval [CI]: 1.12 to 3.61, p=0.02) but not modern (HR 0.98, 95% CI: 0.54 to 1.79, p=0.96) DR techniques were associated with a higher adjusted risk of MACE compared to TTT. CONCLUSIONS: The use of old but not modern DR techniques was associated with a higher risk of MACE. Therefore, CrossBoss/Stingray and reverse CART might be considered as first-line strategies for antegrade and retrograde DR-based CTO PCI, respectively.

Procedural and longer-term outcomes of wire- versus device-based antegrade dissection and re-entry techniques for the percutaneous revascularization of coronary chronic total occlusions.

BACKGROUND: There are few data regarding the procedural and follow-up outcomes of different antegrade dissection/re-entry (ADR) techniques for chronic total occlusion (CTO) percutaneous coronary intervention (PCI). METHODS: We compiled a multicenter registry of consecutive patients undergoing ADR-based CTO PCI at four high-volume specialized institutions. Patients were divided according to the specific ADR technique used: subintimal tracking and re-entry (STAR), limited antegrade subintimal tracking (LAST), or device-based with the CrossBoss/Stingray system (Boston Scientific, Marlborough, MA). Major adverse cardiac events (MACE: cardiac death, target-vessel myocardial infarction and target-vessel revascularization) on follow-up were the main outcome of this study. Independent predictors of MACE were sought with Cox regression analysis. RESULTS: A total of 223 patients were included (STAR n=39, LAST n=68, CrossBoss/Stingray n=116). Baseline characteristics were similar across groups. Technical and procedural success was lower with STAR (59% and 59%), as compared with LAST (96% and 96%) and CrossBoss/Stingray (89% and 87%; p<0.001 for both). At 24-month follow-up, MACE rates were higher in STAR (15.4%) and LAST (17.5%), as compared with device-based ADR with CrossBoss/Stingray (4.3%, p=0.02), driven by TVR (7.7% vs. 15.5% vs. 3.1%, respectively; p=0.02). Multivariable Cox regression analysis identified wire-based ADR (STAR and LAST) and total stent length as independent predictors of MACE. CONCLUSIONS: In this multicenter cohort of patients undergoing CTO PCI with ADR techniques, STAR had lower success rates, as compared with the CrossBoss/Stingray system and LAST. The CrossBoss/Stingray system was independently associated with lower risk of MACE on follow-up, as compared with wire-based ADR techniques.