Successful Chronic Total Occlusion Research Articles

Long‐term clinical outcomes of successful versus unsuccessful revascularization with drug‐eluting stents for true chronic total occlusion

The aims of this study were to investigate the long-term clinical outcomes of patients with successful versus unsuccessful revascularization with drug-eluting stents (DES) for chronic total occlusion (CTO). The benefits of successful revascularization of CTO remain unclear. Consecutive patients (n = 333) with "true" CTO, defined as Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 on angiography and duration ≥3 months, were divided into two groups, those with successful (CTO success group, n = 251) and unsuccessful (CTO failure group, n = 82) revascularization with DES for CTO lesions. The primary endpoint was defined as major adverse cardiac events (MACE) the composite of death, Q-wave myocardial infarction (MI), or target vessel revascularization (TVR). The CTO success group was significantly younger, with a higher involvement of LAD, and lower incidences of renal failure, previous myocardial infarction, and previous coronary intervention than the CTO failure group. After a median follow up of 1,317 days (interquartile range, 1,059-1,590 days), there were no significant between-group differences in rate of MACE, both after crude analysis (9.4% vs. 11.8%, log-rank P = 0.16) and after adjustment (HR 1.17; 95% CI 0.47-2.88, P = 0.53). On multivariate analysis, major predictors of MACE were left ventricle ejection fraction (LVEF) <40% (HR 3.14; 95% CI 1.39-7.09, P = 0.005) and multiple CTO (HR 2.38; 95% CI 1.01-5.71, P = 0.049). Long-term clinical outcomes were similar in the CTO success and failure groups. Multiple CTOs and LVEF <40% in CTO patients were independent predictors of MACE.

Three-Dimensional Quantitative Volumetry of Chronic Total Occlusion Plaque Using Coronary Multidetector Computed Tomography

The purpose of the present study was to investigate whether multidetector computed tomography (MDCT) can identify the nature of chronic total occlusion (CTO) plaque, which cannot be measured quantitatively using traditional coronary angiography, and predict the success of percutaneous coronary intervention (PCI). MDCT and 3-dimensional volumetric radiologic density analysis was performed for 186 consecutive CTO lesions. Plaque characteristics were determined using Hounsfield units (HU) of the image voxels. The remodeling index decreased significantly as the duration of CTO lengthened. Volumetric plaque analysis using HU showed that volumetric fraction of calcification (>324HU) did not, but low-density plaque (<49HU) did decrease significantly as the duration of CTO lengthened. The overall PCI success rate was 77.4% (144/186). In addition to the unknown or >12-month occlusion duration (odds ratio [OR]=3.0, 95% confidence interval [CI]=1.4-6.5, P=0.005), 2 MDCT parameters, that is, lesion length >18mm (OR=2.7, 95%CI=1.1-6.4, P=0.024) and segmental radiologic density >139HU (OR=2.7, 95%CI=1.2-6.4, P=0.021), were independent predictors of PCI failure on multivariate analysis. MDCT might be helpful for the prediction of successful CTO PCI. In addition to the occlusion duration, lesion length and high segmental radiologic density measured on MDCT were significant predictors of PCI failure in the present study.

E0480 Longterm clinical outcome of patients undergoing successful percutaneous coronary intervention for chronic total coronary artery occlusion

IntroductionThere are limited data on the impact of successful chronic total occlusion (CTO) revascularisation by percutaneous coronary intervention (PCI) on long-term outcomes.MethodsBetween June 1993 and December 2006, a total of...

E0479 Impacts of successful percutaneous coronary intervention for chronic total occlusions on patients with heart dysfunction

IntroductionSuccessful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) had proven benefit for long-term survival. However, its impact on heart function of patients with heart dysfunction is uncertain. The...

Effectiveness of recanalization of chronic total occlusions: A systematic review and meta-analysis

Chronic total occlusion (CTO) recanalizations remain extremely challenging procedures. With improvements in technology and techniques, success rates for recanalization of CTO continue to improve. However, the clinical benefits of this practice remain unclear. The aim of the study was to determine the effectiveness of CTO recanalization on clinical outcomes. We performed a systematic review and meta-analysis of published studies comparing CTO recanalization to medical management. Data were extracted in duplicate and analyzed by a random effects model. We did not identify any randomized controlled trials or observational studies comparing CTO recanalization to a planned medical management. We did identify 13 observational studies comparing outcomes after successful vs failed CTO recanalization attempt. These studies encompassed 7,288 patients observed over a weighted average follow-up of 6 years. There were 721 (14.3%) deaths of 5,056 patients after successful CTO recanalization compared to 390 deaths (17.5%) of 2,232 patients after failed CTO recanalization (odds ratio [OR] 0.56, 95% CI 0.43-0.72). Successful recanalization was associated with a significant reduction in subsequent coronary artery bypass graft surgery (CABG) (OR 0.22, 95% CI 0.17-0.27) but not in myocardial infarction (OR 0.74, 95% CI 0.44-1.25) or major adverse cardiac events (OR 0.81, 95% CI 0.55-1.21). In the 6 studies that reported angina status, successful recanalization was associated with a significant reduction in residual/recurrent angina (OR 0.45, 95% CI 0.30-0.67). In highly selected patients considered for CTO recanalization, successful attempts appear to be associated with an improvement in mortality and with a reduction for the need for CABG as compared to failed recanalization. However, given the observational nature of the reviewed evidence, randomized clinical trials are needed to confirm these findings.

Chronic total occlusion special issue

Since its pioneering years, interventional cardiol­ ogy has faced the hurdle of dealing with the spe­ cial case of chronic total occlusion (CTO). Long considered to be the ‘last frontier’ of percutane­ ous coronary interventions, it is only in the last decade that we have finally observed a significant breakthrough in this challenging field, mostly owing to new techniques and materials coming from Japan. Chronic total occlusion procedures now con­ stitute approximately 10–20% of all angio plasty operations at high­volume hospitals [1]. Advances, mainly in guidewire technology, and the develop­ ment of new techniques have increased success rates up to an astounding 90% in specialized cent­ ers with experienced operators [2]. Concomitantly, a reduction of the CTO restenosis rate has been observed with the advent of drug­eluting stents [3]. New data have also highlighted the clinical benefits of CTO revascularization, which, in addition to angina relief, include improvement of left ventricular function, a reduction of major adverse cardiac events and perhaps increased sur­ vival rates [4]. However, an important hurdle on the road to wider utilization of CTO revascu­ larization is that these are long, expensive pro­ cedures that expose the operators to high doses of radiation. A particularly steep learning curve also exists. Complexity of procedures and limited familiarity with new techniques may often lead to premature interruption of procedures, causing both physician and patient frustration and rep­ resenting a common reason for referral to bypass surgery or for choosing medical treatment. Strict adherence to recently developed guidelines [5], especially concerning patient selection, equip­ ment, facilities and proctoring, is thus, in our opinion, essential for an adequate set­up and maintenance of a successful CTO program. Recent advances in CTO techniques that have broadened percutaneous coronary intervention indications and improved success rates can be categorized into anterograde and retrograde approaches [6]. In the presence of visible con­ tralateral collaterals, operators now widely use bilateral injections to allow for simultaneous anterograde and retrograde filling of the target vessel. Anterograde, parallel wire, controlled dissection and microchannel penetration tech­ niques have been developed [7]. Techniques for retrograde penetration of the distal CTO cap are various, with the controlled anterograde and retrograde tracking [8], especially in its ‘reverse’ variety, being particularly popular. However, no consensus exists for s election of the initial approach to a CTO.

Novel high-frequency vibration approach for recanalization of difficult coronary and peripheral chronic total occlusions

Chronic total occlusions (CTOs) continue to be quite prevalent and still present as some of the most challenging lesions for the coronary and/or peripheral interventionalist. Recanalization success rates have been historically low and the potential for adverse events are typically higher than the more common procedures of angioplasty and stenting. At present, there are two paths to successful CTO recanalization; the subintimal approach and the central lumen approach. The subintimal approach tracks a standard guidewire around the occlusion and through the subintimal plane, while the luminal approach attempts to recanalize the occlusion through the central lumen of the artery. After failure to stay in the true lumen, a bypass is essentially created around the occlusion through the adventitia. This may lead to adverse events. A central luminal approach may provide increased safety and more therapeutic options to the clinician and may ultimately deliver enhanced longer-term outcomes owing to the optimization ...

Right coronary artery chronic total occlusion revascularization by knuckle technique through right gastroepiploic artery graft

Sirs:Angina pectoris following bypass surgery is caused bygraft failure or new lesions developing in the native coro-nary artery. Right gastroepiploic artery (RGEA) has beenshown to have a good short- and long-term patency whenanastomosed to the right coronary artery (RCA). Long-term patency is 80–90% at 5 years; however, it decreasesto approximately 62% at 10 years [1].Many reports suggest that successful revascularizationof chronic total occlusion (CTO) subtending viable myo-cardium determines a more favorable long-term outcomewith survival enhancement and improvement in quality oflife [2, 3].We present a case of RCA CTO recanalization usingretrograde approach through RGEA graft.Case reportA 64-year-old man ex smoker with hypercholesterolemia,type II diabetes mellitus, mild hypertension underwentcoronary artery bypass graft (CABG) surgery for anteriormyocardial infarction in 1997 with left internal mammaryartery (LIMA) on left anterior descending (LAD) andRGEA on posterior descending artery (PDA). Since 2003the patient referred onset of angina at medium workload;he performed an exercising test which was interrupted at75 W for V3–V6 down-sloping ST depression and non-sustained ventricular tachycardia. For this reason thepatient was referred for a new coronary angiography(CAG) which showed: LIMA patent, distal LAD withsevere stenosis, RCA proximal occlusion, RGEA patentwith disease at the anastomosis and in native distal RCA(crux) (Fig. 1a–b). The patient was referred for a newCABG in 2004; however, he refused this treatment and hestarted optimal medical therapy. After 5 years, due tosymptoms worsening, the patient underwent CAG (May2009) which showed a comparable angiographic pattern tothe previous one. Thus, the patient underwent a stressmyocardial scintigraphy which showed severe reversibleinfero-lateral hypoperfusion with a normal left ventricularfunction. Thereafter it was decided to attempt RCA per-cutaneous revascularization in June 2009.Unfractionated heparin (5,000 units intravenously) wasadministered. A 7 French Amplatz left and a 7 FrenchJudking right guiding catheter were used to engage RCAostium and RGEA graft, respectively. Contrast meaninjection from RGEA confirmed severe disease at theanastomosis and distally native RCA. The lesion was firstapproached by antegrade with a soft-tapered polymericguidewire (Fielder XT, Asahi) and a microcatheter (Fine-cross, Terumo) which was advanced up to the mid-RCA.As this guidewire was not able to progress any further, itwas exchanged using the microcatheter with an interme-diate-stiffness one (Medium guidewire, Asahi). The Med-ium guidewire was able to advance up to the mid-distal partof the vessel where it stopped due to severe calcifications.Thus, a soft-tapered polymeric guidewire (Fielder XT,Asahi) was inserted with a Corsair microcatheter (Asahi)through RGEA by retrograde. This wire got through thesevere disease at the anastomosis; however, it stuck in the

Quantifying the Early Health Status Benefits of Successful Chronic Total Occlusion Recanalization

Data on the health status benefits of percutaneous coronary intervention for coronary chronic total occlusions (CTOs), a principal indication for the procedure, are lacking. In the FlowCardia Approach to CTO Recanalization (FACTOR) trial, patients (n=125) completed the Seattle Angina Questionnaire (SAQ) at baseline and 1 month after percutaneous coronary intervenion. One-month health status outcomes were compared by multivariable analysis, adjusting for group differences between those whose CTO was successfully and unsuccessfully recanalized. These changes were also analyzed according to baseline symptoms. Procedural success was 55% (n=64) and independently associated with angina relief (difference between those with successful and unsuccessful percutaneous coronary intervention [Delta] in SAQ angina frequency=9.5 points; 95% confidence interval, 1.6 to 17.5; P=0.019), improved physical function (Delta in SAQ physical limitation=13.1 points; 95% confidence interval, 5.1 to 21.1; P=0.001), and enhanced quality of life (Delta in SAQ quality of life [QoL]=20.3 points; 95% confidence interval, 11.9 to 28.6; P<0.001). The benefit of successful percutaneous coronary intervention was greatest in symptomatic patients as compared with asymptomatic patients although statistically significantly so only for QoL (DeltaSAQ angina frequency domain=10.3 versus 4.3 points, P=0.51, Deltaphysical limitation =15.9 versus 6.3 points, P=0.25; DeltaQoL=27.3 versus 8.5 points, P=0.047). Successful CTO recanalization is associated with significant early improvements in patient symptoms, function, and QoL but only among symptomatic patients. Percutaneous treatment of a CTO offers the potential to provide significant health status benefits in symptomatic patients.

PERCUTANEOUS INTERVENTION OF ACUTELY OCCLUDED SAPHENOUS VEIN GRAFTS: CONTEMPORARY TECHNIQUES AND OUTCOMES

OBJECTIVES To examine the contemporary acute and long-term outcomes after percutaneous coronary interventions (PCI) of acutely occluded saphenous vein grafts (SVGs). BACKGROUND PCI of acutely thrombosed SVGs carries low success rates. It is unknown whether outcomes have improved with contemporary PCI techniques. METHODS We reviewed the acute and long-term outcomes of 34 consecutive patients who underwent PCI of 36 acutely occluded SVGs at our institution between 2003 and 2009. RESULTS Mean patient age was 70 +/- 10 years and 39% had stent thrombosis. Mean SVG age was 14 +/- 6 years. SVG PCI was successful in 81%. In 3 patients, PCI of the target vessel native chronic total occlusion (CTO) was attempted after SVG PCI failed and was successful in 2, increasing the overall target myocardial territory revascularization success rate to 86%. Adjunctive PCI techniques were used as follows: mechanical thrombectomy (69%), rheolytic thrombectomy (39%), embolic protection devices (25%) and laser (14%). Stents (61% drug-eluting) were implanted in 78% of the treated lesions. Mean follow up was 2.3 +/- 1.9 years. At 1 and 3 years, mortality was 8% and 42%, an acute coronary syndrome occurred in 15% and 41% and repeat coronary revascularization was required in 28% and 38%, respectively. CONCLUSIONS In this particular population of thrombosed SVG PCIs, a high incidence of stent thrombosis was observed and procedural success rate was 81% with an additional 5% undergoing successful native coronary artery CTO PCI. Patients presenting with thrombosed SVGs were at high risk for recurrent events.

Intraplaque therapies for facilitating percutaneous recanalization of chronic total occlusions

Chronic total occlusions (CTOs) are found in up to 30% of angiograms performed on patients with coronary disease. The technical difficulty of performing percutaneous coronary interventions (PCIs) in CTOs, primarily because of the inability to cross CTOs with a guide wire, is reflected in low rates of PCI for CTo (approximately 9% of PCI procedures). The main barrier to successful CTO crossing is the dense collagenous extracellular matrix, particularly at the entrance, known as the 'proximal fibrous cap'. Current interventional strategies to overcome this barrier are based primarily on forceful penetration of the CTO plaque by the use of dedicated CTO guide wires. These extra-stiff wires are designed to transfer maximal force to the tip to create a path within the plaque. However, these wires can also cause vascular complications such as dissections; overall procedural success rates remain modest. Several groups are working on new approaches to actually alter the biology and structural characteristics of the CTO plaque to facilitate guide wire crossing. Preliminary data suggest that plaque-directed therapies aimed at 'priming' it for wire crossing may increase PCI success in these challenging cases. New techniques for plaque modification, either by 'softening' the collagenous matrix (collagenase) or by exposing and enlarging existing microvessels (intravascular thrombolysis, contrast injection) or by inducing new microvessels (angiogenic growth factor[s]) are described in the present review.

Percutaneous Treatment of Chronic Total Coronary Occlusions Improves Regional Hyperemic Myocardial Blood Flow and Contractility: Insights From Quantitative Cardiovascular Magnetic Resonance Imaging

We sought to investigate temporal changes in contractility and hyperemic and resting myocardial blood flow (MBF) in dependent and remote myocardium after percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) by using cardiovascular magnetic resonance (CMR) imaging. Data about the physiological consequences of revascularization of CTOs are limited. The use of CMR allows investigation of the regional effects of revascularization on MBF and left ventricular contractility. We prospectively recruited 3 patient groups: 17 patients scheduled for CTO PCI, 17 scheduled for PCI of a stenosed but nonoccluded coronary artery (non-CTO), and 6 patients with CTO who were not scheduled for revascularization. All patients undergoing PCI underwent CMR imaging <24 h before PCI, with repeat CMR imaging 24 h and 6 months after PCI. Each CMR scan consisted of cine, perfusion, and delayed enhancement imaging. Regional hyperemic and resting MBF, wall thickening, and transmural extent of infarction were calculated. In both intervention groups, hyperemic MBF in treated segments increased 24 h after PCI compared with baseline: CTO group, 2.1 +/- 0.2 ml/min/g versus 1.4 +/- 0.2 ml/min/g (p < 0.01); non-CTO group, 2.5 +/- 0.2 ml/min/g versus 1.6 +/- 0.2 ml/min/g (p < 0.01). This improvement persisted 6 months after PCI (p < 0.01 for both groups). Contractility in treated segments was improved at 24 h and 6 months after CTO PCI but only at 6 months after non-CTO PCI. In both intervention groups, treated segments no longer had reduced MBF or contractility compared with remote segments. In patients with untreated CTO segments, MBF and wall thickening did not improve at follow-up. Successful CTO PCI increases hyperemic MBF as early as 24 h after the procedure, with a greater and earlier improvement in regional contractility than after non-CTO PCI, despite a greater likelihood of irreversible injury in CTO segments.

Recent Progress of the Use of Interventional Therapy for Chronic Total Occlusion

Chronic total occlusion (CTO) remains one of the most challenging lesion subsets for interventional cardiologists due to a low success rate and higher incidence of restenosis, especially with current use of bare metal stents (BMSs). However, successful CTO revascularization has a beneficial effect on long-term survival and relief of angina. With recent advances in technology (with the use of special techniques and devices), the initial success rate of recanalization of occlusions is quite high (approximately 90%). However, the long-term clinical outcome of the use of bare metal stents is not satisfactory due to a high restenosis rate. Recently, the introduction of the sirolimus-eluting stent (SES) and paclitaxel-eluting stent (PES) has shown favorable clinical outcomes, such as a reduction in the restenosis rate in patients with CTOs. Consequently, the use of the new types of stents can reduce the incidence of major adverse cardiac events detected at follow-up. (Korean Circ J 2008;38:295-300)

Abstract 3420: Effects on Myocardial Perfusion at 3 and 15 Months in Recanalized Chronic Total Occlusions - Randomized Comparison of Blood-Derived Progenitor Cells and Inactive Serum

Background: MRI is an excellent diagnostic tool for serial assessment of changes in myocardial perfusion, left ventricular function, and infarct size. In chronic total occlusions (CTO) the effects of recanalization on perfusion and function are contradictory and might depend primarily on viability. Circulating progenitor cells (CPC) injected intracoronarily after successful CTO recanalization might improve perfusion and function. Methods and results: Twenty-eight patients with reperfused CTO were randomized to either CPC’s or inactive serum (control), which were infused into the target vessel. First-pass myocardial perfusion MRI at rest and stress using adenosine at standard dose revealed a significant improvement of the myocardial perfusion reserve index (MPRI) in the affected segments. The baseline MPRI in affected segments was 1.50±0.17 in CPC versus 1.46±0.16 in control (p=0.62). In CPC the MPRI improved to 1.76±0.16 (p&lt;0.001) at 3 and 1.82±0.20 (p&lt;0.001) at 15 months; in control the change was 1.58±0.10 (p=0.01) at 3 and 1.61±0.08 (p=0.004) at 15 months follow-up. However, the MPRI recovery was significantly better in CPC as compared to control at 3 (p=0.004) and 15 months (p=0.005). In remote myocardium the MPRI was 1.70±0.30 and 1.69±0.25 (p&lt;0.01 versus affected segments), respectively. At follow-up there was no significant improvement for both groups. The change in MPRI at 3 and 15 months was correlated with a change in overall infarct size for CPC (3 months: r=−0.68, p&lt;0.02; 15 months: r=−0.81, p=0.001), whereas in control there was no correlation (r=−0.38, p=0.26; 15 months: r=−0.21, p=0.56). Infarct transmurality influenced MPRI improvement at follow-up. CPC patients had a trend towards more improved segments in particular those with higher transmurality (p=0.06). Conclusions: Analysis of serial contrast-enhanced MRI suggests that intracoronary application of CPC post recanalization of CTO is associated with improved myocardial perfusion and subsequent improved recovery of left ventricular function as compared to a control group at mid- and long-term follow-up. Further investigations of the pathophysiological CPC effects on macro- and microvascular function are required.

Retrograde approach to coronary chronic total occlusions: preliminary single European centre experience

The retrograde approach via septal or epicardial collaterals holds promise in improving the success rate of chronic total occlusion (CTO) recanalisation but is still viewed as an esoteric practice reserved to a selected group of operators using materials not available in Western countries. We sought to introduce the novel technique of retrograde CTO recanalisation to our institution using materials and resources available outside Japan. Between April 2005 and 2007, all patients with a failed antegrade attempt at CTO recanalisation were considered and selected based on their appropriateness to have a retrograde procedure. Seventeen patients were included. Average age was 65.3 years. The mean occlusion duration was 33.3 months. Successful CTO recanalisation was achieved in 15 of 17 (88.2%) patients. A retrograde wire was successfully advanced into the distal occluded vessel and facilitated successful CTO recanalisation in 13 (76.5%) patients. Final retrograde wire crossing was achieved in seven cases, while in the remaining cases, the CART technique (n=4) and 'knuckle' technique (n=2) were successful. In two cases (11.8%), the retrograde wire did not reach the distal occlusion because of septal tortuosity but a repeat antegrade attempt, aided by contralateral visualisation, was successful. In two (11.8%) patients, the procedure was unsuccessful. Cardiac magnetic resonance imaging performed in five of the successfully treated retrograde cases (45.5%) showed variable degrees of fibrosis in the territory of the occluded artery with no significant change after the procedure with the exception of one case of contained contrast extravasation within the septum. The novel method of retrograde recanalisation of CTOs was performed with a high procedural success in this series and was applicable in 37.1% of previously failed antegrade procedures. This technique can also be successfully employed despite newly created dissections immediately following a failed antegrade attempt.

Percutaneous coronary intervention for chronic total occlusions: Improved survival for patients with successful revascularization compared to a failed procedure

There are limited data on the impact of successful chronic total occlusion (CTO) revascularization by percutaneous coronary intervention (PCI) on survival. We performed a retrospective study comparing the survival between patients with a successful and a failed CTO revascularization by PCI. Between January 1, 2000 and June 30, 2004, 543 of 5803 (9.4%) patients underwent PCI for a CTO at our center. A CTO was defined as an occlusion of the artery present for at least 3 months with Thrombolysis in Myocardial Infarction flow grade 0 or 1. Patient records were linked to a national database to monitor all deaths during follow up. Propensity matching was used to balance out case mix differences. Technical success for CTO was 377 of 543 (69.4%). In-hospital mortality was 0.3% and 1.2% for the CTO success and CTO failure patients, respectively. During a mean (SD) follow up of 1.7 (0.5) years, the mortality rate was 2.5% in the CTO success patients and 7.3% in the CTO failure patients. The crude hazard ratio for death with CTO failure was 3.92 (95% confidence intervals 1.56-10.07; P = 0.004). The rates of coronary artery bypass were 3.2% vs. 21.7% (P < 0.001) for the CTO success and CTO failure patients, respectively. Our propensity matched 157 CTO success to CTO failure patients and the associated hazard ratio for death with CTO failure was 4.63 (95% confidence interval 1.01-12.61; P = 0.049). Multivariate analysis showed that CTO failure was an independent predictor of death. Patients with a successful revascularization of a CTO by PCI have an increased survival rate compared to patients with a failed CTO procedure.

Chronic total occlusions

Chronic total occlusions (CTOs) represent the “last frontier” of percutaneous coronary interventions (PCI). CTOs are frequently ( 30 %) detected on diagnostic coronary angiograms, but CTO PCI is currently performed infrequently mainly because of higher technical difficulty and perceived risk of complications. Nonetheless, successful CTO PCI can significantly improve the patient’s quality of life, improve left ventricular function, reduce the need for subsequent coronary artery bypass graft surgery, and possibly improve long-term survival. The introduction of novel catheters, guidewires, adjunctive imaging, PCI techniques, and higher operator volumes has led to an increased success rate of CTO PCI. Moreover, the introduction of drug-eluting stents has led to higher rates of sustained patency following CTO recanalization. This chapter aims to provide an overview of the anatomy and histopathology of CTOs, a concise review of techniques and devices for CTO PCI, and a comprehensive summary of the evidence regarding the clinical relevance and rationale of CTO PCI.

The challenges of chronic total coronary occlusions: an old problem in a new perspective.

In spite of the remarkable technological innovation and improved outcomes with percutaneous coronary revascularization, chronic coronary artery total occlusions remain a familiar source of procedural frustration and clinical uncertainty. However, considering the recent development of catheter-based technologies specific for chronic total occlusion (CTO) recanalization and the potential for drug-eluting stents to reduce restenosis and reocclusion, this challenging lesion subset is now recognized as the last formidable barrier to percutaneous revascularization success. Further, consistent observations from more recent clinical trials support successful CTO revascularization to avoid subsequent adverse cardiac events and improve long-term overall survival. This review of total coronary occlusions provides an overview of CTO pathophysiology, describes the procedural and clinical outcomes associated with CTO revascularization, and presents future directions for clinical investigation.