In-hospital outcomes of percutaneous coronary intervention in patients with chronic total occlusion: insights from the ERCTO (European Registry of Chronic Total Occlusion) registry

Reducing radiation in chronic total occlusion percutaneous coronary interventions

The field of percutaneous intervention for chronic total occlusion (CTO) has enjoyed significant innovations in the recent years. Novel techniques and technologies have revolutionized the field and have resulted in considerably higher success rates even in patients with high anatomical complexity. Successful CTO recanalization is associated with significant clinical benefits, such as the improvement of angina and quality of life, reduced rates of surgical revascularization, improvement of left ventricular function and decreased mortality rates. However, complex CTO procedures often require prolonged x-ray exposure which have been associated with adverse long term outcomes.

Comparison of second- and first-generation drug eluting stent for percutaneous coronary chronic total occlusion intervention

BACKGROUND

The performance of contemporary second-generation drug-eluting stents (DESs) for percutaneous chronic total occlusion (CTO) intervention is not well established. The present study compared the efficacy and safety outcomes of second-generation DESs with those of first-generation DESs in CTO-percutaneous coronary intervention (PCI).

METHODS

This retrospective analysis included 1049 consecutive CTO patients who underwent successful DES implantation (first-generation; 487 vs. second-generation; 562 patients) between March 2003 and August 2014. The primary endpoint was the composite of all-cause death, Q-wave myocardial infarction (MI), or target-vessel revascularization (TVR).

RESULTS

During a follow-up of 3 years, the primary endpoint incidence was 10.1% for second- and 7.7% for first-generation DES (p=0.30). After multivariable adjustment, there was no significant difference between these groups in terms of the risk of composite of death, Q-wave MI, or TVR (Hazard ratio [HR] 1.42, 95% confidence interval [CI] 0.88-2.28, p=0.15) nor in the individual risks of death (adjusted HR 1.33, 95% CI 0.69-2.56, p=0.39), Q-wave MI (adjusted HR 1.15, 95% CI 0.30-4.47, p=0.84) and TVR (adjusted HR 1.06, 95% CI 0.52-2.15, p=0.87). The incidence of definite/probable stent thrombosis was relatively low (0.5% vs.0.9%, p=0.17) throughout the follow-up period.

CONCLUSION

The 3-year clinical outcomes of patients treated with second-generation DESs are comparable to those treated with first-generation DESs for CTO-PCI.

Retrograde Coronary Chronic Total Occlusion Intervention

Coronary chronic total occlusion (CTO) is a frequent finding in patients with coronary artery disease. It remains one of the most challenging subsets, accounting for 10-20% of all percutaneous coronary interventions (PCI). Although remarkable progress in PCI has been made, it is reasonable to state that successful recanalization of CTO represents the “last frontier" of PCI. PCI of CTOs has been limited historically by technical success rates of 50-70%. The introduction of enhanced guidewires, microcatheter, channel dilatator with increasing operator experience, and innovative techniques such as the retrograde approach have raised hopes for better outcomes. This article goes into depth into various strategies of retrograde approach in CTO.

Recanalization of chronic total coronary occlusions--high success rate despite a restrictive use of the retrograde approach

AIM

The retrograde approach in chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is increasingly being used as a first-line intervention despite a higher radiation exposure, contrast volume, and a higher major adverse cardiac event (MACE) rate compared with the antegrade approach. It was aimed to evaluate the overall success rate of CTO-PCI over time when the retrograde approach was restrictively used only after a failed antegrade attempt.

METHODS AND RESULTS

In a prospective single operator registry from January 2008 to December 2012 about 436 consecutive patients underwent a CTO-PCI. Mean age was 63.4 ± 10.3 years, and 86% were male. The overall success rate improved significantly over time [68% (first quartile) to 91% (fourth quartile), P < 0.001] due to a significant increase of the antegrade success rate. This could be achieved by a retrograde approach of less than 20% with no change over time. The overall in-hospital MACE rate was 0.69% with no difference between antegrade and retrograde procedures.

CONCLUSIONS

A high CTO-PCI success rate of above 90% could be achieved with a restrictive use of the retrograde technique.

Real-World Use and Appropriateness of Coronary Interventions for Chronic Total Occlusion (from a Japanese Multicenter Registry)

Little is known about the outcomes and indications of chronic total occlusion percutaneous coronary intervention (CTO-PCI), other than in high-volume centers. We sought to provide a real-world overview of the clinical outcomes and appropriateness of PCI for CTO. The analysis included 4,950 consecutive PCIs for nonacute indications registered in the multicenter Japanese PCI registry in collaboration with the US National Cardiovascular Data Registry (Cath-PCI). Data included demographics, clinical outcomes (procedural success and complication rates), and the indication appropriateness, based on the 2012 appropriate use criteria for revascularization. The overall procedural success and major adverse cardiac event rates of 501 cases with CTO-PCI (10.1%) were 76% and 3.2%, respectively. Based on the criteria, mapping failures occurred in 2,521 procedures; the remaining 2,429 PCIs were successfully mapped. The CTO-PCIs were performed for more appropriate indications than PCIs for lesions without CTO. The rate of inappropriate indications was significantly lower in CTO-PCIs than in non-CTO-PCIs (23.0% vs 31.4%, p = 0.04). Only 17% of CTO-PCIs were directly assigned to CTO-specific scenarios because such scenarios are only intended for "Lone" CTO; the rest of the CTO-PCI cases were secondarily mapped to non-CTO-specific scenarios. In conclusion, as many as 10% of the elective PCIs were performed for CTO lesions in a contemporary multicenter Japanese PCI registry; CTO-PCI was associated with lower procedural success and higher complication rates than non-CTO-PCI. Its indication was relatively appropriate; however, our findings emphasize the need for more rigorous evaluation in terms of the present insufficient CTO-related clinical scenarios.

Comparison of magnetic wire navigation with the conventional wire technique for percutaneous coronary intervention of chronic total occlusions: a randomised, controlled study

Wire crossing of a chronic total coronary occlusion (CTO) is time consuming and limited by the amount of contrast agent and time of radiation exposure. Magnetic wire navigation (MWN) might accelerate wire crossing by maintaining a coaxial vessel orientation. This study compares MWN with the conventional approach for recanalization of CTOs. Forty symptomatic patients with CTO were randomised to MWN (n = 20) or conventional approach (n = 20) for antegrade crossing of the occlusion. In the intention-to-treat analysis, MWN showed a shorter crossing time (412 versus 1131 s; p = 0.001), and, consequently, lower usage of contrast agent (primary endpoint 42 versus 116 ml; p = 0.01), and lower radiation exposure (dose-area product: 29 versus 80 Gy*cm(2); p = 0.002) during wire crossing compared to the conventional approach. Accordingly, in the per-protocol analysis, the wire-crossing rate was, in trend, higher using the conventional approach (17 of 31) compared to MWN (9 of 28; p = 0.08). The use of MWN for revascularisation of CTOs is feasible and reduces crossing time, use of contrast agent, and radiation exposure. However, due to a broader selection of wires, the conventional approach enables wire crossing in cases failed by MWN and seems to be the more successful choice.

Application and outcomes of a hybrid approach to chronic total occlusion percutaneous coronary intervention in a contemporary multicenter US registry

BACKGROUND

A hybrid approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) prioritizing and combining all available crossing techniques was developed to optimize procedural efficacy, efficiency, and safety, but there is limited published data on its outcomes.

METHODS

We examined the procedural techniques and outcomes of 1036 consecutive CTO PCIs performed using a hybrid approach between 2012 and 2015 at 11 US centers.

RESULTS

Mean age was 65 ± 10 years and 86% of the patients were men, with a high prevalence of diabetes mellitus (43%) and prior coronary artery bypass graft surgery (34%). Most target CTOs were located in the right coronary artery (59%), followed by the left anterior descending artery (23%) and the circumflex (19%). Dual injection was used in 71%. Technical success was achieved in 91% and a major procedural complication occurred in 1.7% of cases. The final successful crossing technique was antegrade wire escalation in 46%, antegrade dissection/re-entry in 26%, and retrograde in 28%. The initial crossing strategy was successful in 58% of the lesions, whereas 39% required an additional approach. Overall, antegrade wire escalation was used in 71%, antegrade dissection/re-entry in 36%, and the retrograde approach in 42% of procedures. Median contrast volume, fluoroscopy time, and air kerma radiation dose were 260 (200-360) ml, 44 (27-72) min, and 3.4 (2.0-5.4) Gray, respectively.

CONCLUSION

Application of a hybrid approach to CTO crossing resulted in high success and low complication rates across a varied group of operators and hospital practice structures, supporting its expanding use in CTO PCI.

Knowledge of chronic total occlusion among Polish interventional cardiologists

Introduction

Chronic total occlusion (CTO) recanalization is indicated in patients with symptoms and evidence of ischemia, but in most cases those types of lesions are still treated medically. In the last few years CTO angioplasty technique has changed dramatically due to considerable advances in techniques and dedicated equipment.

Aim

An attempt to assess the state of knowledge of technical aspects of CTO angioplasty of coronary arteries among Polish interventional cardiologists.

Material and methods

Questionnaire survey performed during two major Polish invasive cardiology workshops.

Results

In the study there participated 113 physicians with an average length of work experience of 13 years, most of them cardiologists certified as independent primary operators. The majority of respondents recognized the need of prevention of thrombotic complications through control of activated coagulation time during the CTO procedures. Prevention of renal complications and X-ray protection are also recognized as a significant part of the procedures. The benefits from the use of over-the-wire microcatheters and balloons, the proper choice of dedicated guidewires, contralateral injections and retrograde technique are underestimated.

Conclusions

Despite satisfactory knowledge about indications and qualification for the CTO procedure, the awareness of procedural aspects (particularly the retrograde technique) as well as the dedicated CTO equipment among Polish interventional cardiologists is still insufficient.

Value of Hybrid Imaging with PET/CT to Guide Percutaneous Revascularization of Chronic Total Coronary Occlusion

Chronic total coronary occlusions (CTO) are documented in approximately one fifth of diagnostic invasive coronary angiographies (ICA). Percutaneous coronary interventions (PCI) of CTO are challenging and are accompanied by higher complication and lower success rates in comparison with non-CTO PCI. Scrutinous evaluation of ischemia and viability to justify percutaneous revascularization is therefore of importance to select eligible patients for such a procedure. Furthermore, knowledge of the anatomical features of the occlusion may predict the chances of success of PCI CTO and could even guide the procedural strategy to augment the likelihood of recanalization. Positron emission tomography (PET) is unequivocally accepted as the reference standard for ischemia and viability testing, whereas coronary computed tomography angiography (CCTA) currently allows for non-invasive detailed three-dimensional imaging of the coronary anatomy that adds morphological information over two-dimensional ICA. Hybrid PET/CT could therefore be useful for optimal patient selection as well as procedural planning. This review discusses the potential value of PET/CT to guide PCI in CTOs.

Prevention of contrast-induced acute kidney injury after percutaneous coronary intervention for chronic total coronary occlusions

Chronic total occlusions (CTOs) represent a major challenge in percutaneous coronary revascularization. The recent advances in strategies and techniques and the development of dedicated equipment, such as microcatheters and wires, have resulted in considerably higher success rates. Although successful CTO recanalization is associated with significant clinical benefits, including improvement of angina, quality of life, reduced need for surgical revascularization, and improvement of left ventricular function, CTO procedures may require prolonged x-ray exposure and use of larger volumes of contrast compared with non-CTO procedures. Large volumes of contrast medium have been associated with increased rates of contrast-induced acute kidney injury (CI-AKI) and adverse short- and long-term outcomes. Application of specific measures and algorithms should be considered by all CTO operators to prevent CI-AKI.

Coronary perforation with tamponade successfully managed by retrograde and antegrade coil embolization

In recent years, retrograde approach for chronic total occlusions has rapidly evolved, enabling a higher rate of revascularization success. Compared to septal channels, epicardial collaterals tend to be more tortuous, more difficult to negotiate, and more prone to rupture. Coronary perforation is a rare but potentially life-threatening complication of coronary angioplasty, often leading to emergency cardiac surgery. We report a case of a retrograde chronic total occlusion revascularization through epicardial collaterals, complicated by both retrograde and antegrade coronary perforation with tamponade, and successfully managed by coil embolization.

Complex Coronary Interventions with the Novel Mozec™ CTO Balloon: The MOZART Registry

BACKGROUND

Mozec™ CTO is a novel semicompliant rapid-exchange PTCA balloon catheter with specific features dedicated to treat complex coronary lesions like chronic total occlusions (CTOs). However, no data have been reported about the performance of this device in an all-comers population with complex coronary lesions.

METHODS

We evaluated the safety and success rate of Mozec™ CTO balloon in 41 consecutive patients with chronic stable angina and complex coronary lesions (15 severe calcified coronary stenoses, 15 bifurcation lesions with planned two-stent intervention, and 11 CTOs). Safety was assessed reporting the balloon burst rate after inflation exceeding the rated burst pressure (RBP) according to the manufacturer’s reference table. Success was defined as the possibility to advance the device further the target lesion.

RESULTS

The Mozec™ CTO balloon showed an excellent performance with a 93.3% success in crossing tight and severely calcified lesions (14/15 pts), a 93.3% success in engaging jailed side branches after stent deployment across bifurcations (14/15 pts), and a 90.9% success in crossing CTO lesions (10/11 pts). The burst rate at RBP of the Mozec™ CTO balloon was 6.7% (1/15 balloons) in the tight and severely calcified lesions, 6.7% (1/15 balloons) when dilating jailed vessels, and 9.1% (1/11 balloons) in CTOs.

CONCLUSIONS

The novel Mozec™ CTO balloon dilatation catheter showed promising results when employed to treat complex lesions in an all-comers population. Further studies should clarify if this kind of balloon might reduce the need of more costly devices like over-the-wire balloons and microcatheters for complex lesions treatment.

Chronic total occlusions in Sweden--a report from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

INTRODUCTION

Evidence for the current guidelines for the treatment of patients with chronic total occlusions (CTO) in coronary arteries is limited. In this study we identified all CTO patients registered in the Swedish Coronary Angiography and Angioplasty Registry (SCAAR) and studied the prevalence, patient characteristics and treatment decisions for CTO in Sweden.

METHODS AND RESULTS

Between January 2005 and January 2012, 276,931 procedures (coronary angiography or percutaneous coronary intervention) were performed in 215,836 patients registered in SCAAR. We identified all patients who had 100% luminal diameter stenosis known or assumed to be ≥ 3 months old. After exclusion of patients with previous coronary artery bypass graft (CABG) surgery or coronary occlusions due to acute coronary syndrome, we identified 16,818 CTO patients. A CTO was present in 10.9% of all coronary angiographies and in 16.0% of patients with coronary artery disease. The majority of CTO patients were treated conservatively and PCI of CTO accounted for only 5.8% of all PCI procedures. CTO patients with diabetes and multivessel disease were more likely to be referred to CABG.

CONCLUSION

CTO is a common finding in Swedish patients undergoing coronary angiography but the number of CTO procedures in Sweden is low. Patients with CTO are a high-risk subgroup of patients with coronary artery disease. SCAAR has the largest register of CTO patients and therefore may be valuable for studies of clinical importance of CTO and optimal treatment for CTO patients.

Percutaneous Treatment of Coronary Chronic Total Occlusions Part 1: Rationale and Outcomes

Coronary chronic total occlusions (CTOs) are commonly encountered in patients with coronary artery disease. Compared to patients without coronary CTOs, those with CTO have worse clinical outcomes and lower likelihood of complete coronary revascularisation. Successful CTO percutaneous coronary intervention (PCI) can significantly improve angina and improve left ventricular function. Although currently unproven, successful CTO PCI might also reduce the risk for arrhythmic events in patients with ischaemic cardiomyopathy, provide better tolerance of future acute coronary syndrome, and possibly improve survival. Evaluation by a heart team comprised of both interventional and non-interventional cardiologists and cardiac surgeons is important for determining the optimal revascularisation strategy in patients with coronary artery disease and CTOs. Ad hoc CTO PCI is generally not recommended, so as to allow sufficient time for (a) discussion with the patient about the indications, goals, risks, and alternatives to PCI; (b) careful procedural planning; and (c) contrast and radiation exposure minimisation. Use of drug-eluting stents is recommended for CTO PCI, given the lower rates of angiographic restenosis compared to bare metal stents.

Clinical significance of a single multi-slice CT assessment in patients with coronary chronic total occlusion lesions prior to revascularization

Accurate assessment of coronary chronic total occlusion (CTO) lesion is essential to design an appropriate procedural strategy before revascularization. The present study aims to evaluate the significance of a single multislice computed tomography (MSCT) examination in patients with CTO lesion. We retrospectively analyzed the clinical data of 23 CTO lesions in twenty patients underwent computed tomography coronary angiography (CTCA) and SPECT. The CTCA was more powerful and sensitive to determine the CTO lesion length (100% v.s 47.8%) and to identify the length and location of calcification in occluded vessels compared with the coronary angiography (CAG). The LVEF measured by MSCT was comparable to that from the gated SPECT. Myocardial perfusion imaging showed that the location of the early defect region identified by MSCT was corresponded to the nuclide filling defect on the stressed 201thallium-SPECT imaging. The late hyperenhancement on MSCT was presented as incomplete nuclide filling on the 99mTc-MIBI imaging. The results suggested that a single MSCT examination in previous myocardial infarction without revascularization facilitates to provide some valuable information on the nature of the occluded lesion, myocardial perfusion and globe cardiac function, which would be helpful to design appropriate revascularization strategy in these subjects.

Contemporary overview and clinical perspectives of chronic total occlusions

Chronic total occlusions (CTOs) are often detected on diagnostic coronary angiograms, but percutaneous coronary intervention (PCI) for CTO is currently infrequently performed owing to high technical difficulty, perceived risk of complications, and a lack of randomized data. However, successful CTO-PCI can significantly increase a patient's quality of life, improve left ventricular function, reduce the need for subsequent CABG surgery, and possibly improve long-term survival. A number of factors must be taken into account for the selection of patients for CTO-PCI, including the extent of ischaemia surrounding the occlusion, the level of myocardial viability, coronary location of the CTO, and probability of procedural success. Moreover, in patients with ST-segment elevation myocardial infarction, a CTO in a noninfarct-related artery might lead to an increase in infarct area, increased end-diastolic left ventricular pressure, and decreased left ventricular function, which are all associated with poor clinical outcomes. In this Review, we provide an overview of the anatomy and histopathology of CTOs, perceived benefits of CTO-PCI, considerations for patient selection for this procedure, and a summary of emerging techniques for CTO-PCI.

The role for adjunctive image in pre-procedural assessment and peri-procedural management in chronic total occlusion recanalisation

Non invasive coronary angiography with multislice computed tomography has exquisite sensitivity to detect calcium and even the faintest late contrast filling of the distal vessel. Calcium burden and occlusion length are still valuable markers of duration, complexity and success of the recanalisation procedure. The ability to visualise the vessel also in the occluded segment, especially if calcified, can also help the operator to understand where to pierce the proximal cap in stumpless occlusions and to predict unusual courses, especially in very tortuous arteries. Imaging side by side CT images and angiography during the recanalisation procedure is an established practice in many active CTO laboratories and algorithms for co-registration are designed to overcome the challenges of systo-diastolic and respiratory motion. Intravascular ultrasound is used in almost all cases by the experienced Japanese CTO operators but most of the times its main use is a better identification of the diseased segment after predilatation to ensure complete stent cover and appropriate stent expansion, an application similar to other complex non occlusive lesions. The specificity of IVUS during CTO recanalisation is the identification of the vessel path in stumpless occlusions and the guidance of wire reentry especially during reverse Controlled Retrograde Anterograde Tracking. Optical coherence tomography has limitations in the setting of CTO recanalisation because of the need of forceful contrast flushing to clear blood, contraindicated in the presence of anterograde dissections, and the limited penetration. The variability in the use of both non-invasive and invasive imaging during CTO recanalisation is immense, going from more than 90% in Japan to less than 20% in Europe and intermediate penetration in the USA. Probably the explanation is almost only in availability and cost because all countries see a progressive increase of use suggesting that these methods are becoming an established tool for guidance of CTO recanalisation.

Advances in the management of coronary chronic total occlusions

Chronic total occlusions (CTOs) have been called "the last frontier" of percutaneous coronary intervention (PCI) due to traditionally low success rates and high risk for restenosis and re-occlusion. Recent advances in equipment and crossing techniques have significantly increased CTO PCI success rates while maintaining low risk of complications. Specifically, the retrograde approach and controlled antegrade dissection and re-entry in conjunction with advanced guidewires and microcatheters have significantly improved procedural success rates. Moreover, the introduction of the "hybrid" approach has created a unified framework for operators to approach CTOs in a systematic and efficient fashion. Finally, drug-eluting stents, especially second generation, have improved long-term patency after CTO PCI.

Intravascular ultrasound-guided chronic total occlusion wiring technique using 6 Fr catheters via bilateral transradial approach

A blunt stump-type entry of chronic total occlusion (CTO) is one of the most difficult morphologic features to overcome in percutaneous coronary intervention (PCI), which often requires the guidance of intravascular ultrasound (IVUS) to identify the entry point. However, real-time, IVUS-guided PCI usually requires an 8 Fr guiding catheter. In this report, we describe a successful PCI for blunt stump CTO using bi-radial, IVUS-guided CTO wiring technique. Two 6 Fr guiding catheters (one as an operating guidewire; second for IVUS imaging) were simultaneously inserted into the left coronary artery via bilateral radial arteries. This technique may be useful for CTO intervention.

Temporal trends of fluoroscopy time and contrast utilization in coronary chronic total occlusion revascularization: insights from a multicenter United States registry

BACKGROUND

The impact of operator experience on fluoroscopy time and contrast utilization during percutaneous coronary intervention (PCI) of coronary chronic total occlusions (CTOs) has received limited study.

METHODS

We evaluated temporal trends in fluoroscopy time and contrast utilization among 1,363 consecutive CTO PCIs performed at three US institutions between January 2006 and November 2011.

RESULTS

Mean age was 65 ± 11 years, 85% of patients were men, 40% had diabetes, 37% had prior coronary artery bypass graft surgery, and 42% had prior PCI. The CTO target vessel was the right coronary artery (55%), circumflex (23%), left anterior descending artery (21%), and left main or bypass graft (1%). The retrograde approach was used in 34% of all procedures. The technical and procedural success rates were 85.5 and 84.2%, respectively. The mean procedural time, fluoroscopy time, and contrast utilization were 113 ± 61 min, 42 ± 29 min, and 294 ± 158 mL, respectively. Years since initiation of CTO PCI were independently associated with higher technical success rate (odds ratio [OR] = 1.52, 95% confidence interval [CI] = 1.52-1.70, P < 0.001), lower fluoroscopy time (OR = 0.84, 95% CI = 0.75-0.95, P = 0.005), and contrast utilization (OR = 0.84, 95% CI = 0.62-0.79, P < 0.001) during the study period.

CONCLUSIONS

Among selected US-based institutions performing CTO PCI, we observed a significant reduction in total fluoroscopy time and contrast utilization paralleled with an improved technical success rate over time.

Periprocedural myocardial injury in chronic total occlusion percutaneous interventions: a systematic cardiac biomarker evaluation study

OBJECTIVES

This study sought to evaluate the incidence, correlates, and clinical implications of periprocedural myocardial injury (PMI) during percutaneous coronary intervention (PCI) of chronic total occlusions (CTO).

BACKGROUND

The risk of PMI during CTO PCI may be underestimated because systematic cardiac biomarker measurement was not performed in published studies.

METHODS

We retrospectively examined PMI among 325 consecutive CTO PCI performed at our institution between 2005 and 2012. Creatine kinase-myocardial band fraction and troponin were measured before PCI and 8 to 12 h and 18 to 24 h after PCI in all patients. PMI was defined as creatine kinase-myocardial band increase ≥ 3 x the upper limit of normal. Major adverse cardiac events during mid-term follow-up were evaluated.

RESULTS

Mean age was 64 ± 8 years. The retrograde approach was used in 26.8% of all procedures. The technical and procedural success was 77.8% and 76.6%, respectively. PMI occurred in 28 patients (8.6%, 95% confidence intervals: 5.8% to 12.2%), with symptomatic ischemia in 7 of those patients. The incidence of PMI was higher in patients treated with the retrograde than the antegrade approach (13.8% vs. 6.7%, p = 0.04). During a median follow-up of 2.3 years, compared with patients without PMI, those with PMI had a higher incidence of major adverse cardiac events (hazard ratio [HR]: 2.25, p = 0.006). Patients with only asymptomatic PMI also had a higher incidence of major adverse cardiac events on follow-up (HR: 2.26, p = 0.013).

CONCLUSIONS

Systematic measurement of cardiac biomarkers post-CTO PCI demonstrates that PMI occurs in 8.6% of patients, is more common with the retrograde approach, and is associated with worse subsequent clinical outcomes during mid-term follow-up.

Percutaneous Treatment of Coronary Chronic Total Occlusion Part 2: Technical Approach

Dual injection is recommended for nearly all chronic total occlusion (CTO) percutaneous coronary intervention (PCI) to determine the optimal crossing strategy and guide wire advancement into the distal true lumen. Strategies that provide enhanced guide catheter support (such as long sheaths, large-bore guiding catheters, use of guide catheter extensions, and anchor techniques) are important for maximising the success rate and efficiency of CTO PCI. Use of a microcatheter or over-the-wire balloon is strongly recommended in CTO PCI for enhancing the penetrating power of the guidewire, enabling change in tip shape and allowing guidewire change (stiff CTO guidewires are not optimal for crossing non-occluded coronary segments). Adherence to a procedural strategy that standardises CTO technique and facilitates procedural success is recommended. Such a strategy would permit stepwise decision-making for antegrade and retrograde methods; inform guidewire selection; and incorporate alternative approaches for instances of initial failure. Given the paucity of long-term outcomes with use of novel crossing techniques (antegrade dissection/re-entry and retrograde), antegrade wire escalation is the preferred CTO crossing technique, if technically feasible. Using measures to minimise radiation exposure (including but not limited to use of 7.5 frames per second fluoroscopy and use of low magnification) and contrast administration is recommended. CTO PCI is best performed at centres with dedicated CTO PCI experience and expertise. Use of crossing difficulty prediction tools, such as the J-CTO score, can facilitate the selection of cases with a high likelihood of quick crossing that can be attempted at less experienced centres.