Chronic Total Occlusions: Patient Selection and Overview of Advanced Techniques

The outcomes and complications of percutaneous interventions in chronic total coronary occlusion

BACKGROUND

The limited availability of complex coronary intervention facilities and qualified operators, due to the high cost associated with chronic total occlusion (CTO) percutaneous intervention (PCI) equipment and a shortage of necessary skills, has led to a scarcity of capable medical centers in Pakistan. This study seeks to examine the outcomes and potential complications associated with CTO PCI procedures conducted at the Cardiac Catheterization Laboratories of a prominent national institute in Pakistan, which handles a large volume of cases.

RESULTS

Three hundred and six patients were included in the study in the study period of six months. The mean age was 59.49 (± 9.16) years: 256 (83.66%) were male and 50 (16.34%) were female. CTO was successfully re-vascularized in 237 (77.5%) with a complication rate of 13.7%. Two hundred and ninety-eight (97.39%) patients underwent an antegrade approach, while RCA was the most common target vessel (47.71%). Diabetes was the only significant associated risk factor with CTO PCI failure (30.43% vs. 30.43%, P-value = 0.015).

CONCLUSION

We achieved an excellent procedural success rate with a low complication rate. CTO procedural failure is associated with a higher complication rate, and diabetes is among the risk factors that lead to higher procedural failure.

Complications of chronic total occlusion percutaneous coronary intervention

Chronic total occlusion percutaneous coronary interventions can be highly complex and are associated with an increased risk of complications, such as perforation, acute vessel closure (which can lead to rapid haemodynamic compromise if it involves the donor vessel), and equipment loss or entrapment. Awareness of the potential complications and meticulous attention to equipment position and patient monitoring can help minimise the risk of complications and allow prompt treatment should they occur.

Examining the Operator Learning Curve for Percutaneous Coronary Intervention of Chronic Total Occlusions

Background:

Advances in chronic total occlusion percutaneous coronary intervention (CTO PCI) techniques have led to increased procedural success rates among operators. While utilization of CTO PCI has disseminated widely, the learning curve for new operators has not been well-defined.

Methods:

Between July 2009 and December 2015, 93 875 CTO PCI cases were extracted from the CathPCI Registry. We delineated a cohort of new CTO operators performing <10 CTO PCI cases per given year. In-hospital outcomes for subsequent CTO PCIs were stratified by the number of prior cases accrued by each operator. Multivariable regression models were used to estimate differences in outcomes with increasing experience. The primary outcome was major adverse cardiovascular events defined as the composite of death, myocardial infarction, stroke, tamponade, or urgent coronary artery bypass grafting.

Results:

Among 70 916 cases performed by 7251 new operators, procedure success rate was 61.4% and major adverse cardiovascular event rate was 4.2%. Meanwhile, the rate of major bleeding was 4.0%, myocardial infarction 2.0%, mortality 0.6%, tamponade 0.3%, and renal failure 0.2%. Adjusted regression models demonstrated piecewise linear improvements in guidewire crossing, stent placement, and procedure success with accrued volume, albeit with increased contrast use, fluoroscopy time, and bleeding. Major adverse cardiovascular event rates were stable beyond the 12th case (odds ratio per 5 case increase 1.00; 95% CI, 0.98–1.03, P =0.7980).

Conclusions:

Among a large number of new CTO PCI operators in the United States, there exists an experiential learning curve for procedural success. However, there were higher rates of bleeding despite case experience, while major adverse cardiovascular events remained relatively unchanged after initiation.

Optical coherence tomography evaluation of the absorb bioresorbable scaffold performance for overlap versus non-overlap segments in patients with coronary chronic total occlusion: insight from the GHOST-CTO registry

The Absorb bioresorbable vascular scaffold (BVS) promised to avoid some of the disadvantages of its metal predecessors. Even though it has been taken off the market, limited data is available about its use in coronary chronic total occlusion (CTO) and its performance in overlap segments, which would be of special research interest due to its large thickness. This data is still pertinent since the platform of bioresorbable devices has not been abandoned, with several companies working on it. We aimed to compare healing and performance between overlap (OL) and non-overlap regions (NOL) of CTO lesions treated with BVS, using optical coherence tomography (OCT). Fourteen patients with overlapping BVS were included from the GHOST-CTO registry, resulting in 25 OL and 38 NOL regions. OCT based parameters were compared between OL and NOL groups at baseline (post-implantation) and 12-month follow-up. The mean age was 61.7 ± 7.2 years and 12 (86%) were males. Twelve (86%) patients underwent PCI for stable coronary artery disease and 2 (14%) had unstable angina. At 12-month follow-up, mean lumen area decreased in both NOL and OL regions, but the decrease was significantly larger in the OL region (NOL - 0.7 ± 1.33 vs. OL - 2.4 ± 1.54 mm²; p = 0.002). Mean scaffold area increased in both regions, but increased significantly more in NOL ( + 1.1 ± 1.54 vs. + 0.4 ± 1.16 mm²; p = 0.016). The percent of uncovered struts was lower in the OL group (5.0 ± 6.6% vs. 3.75 ± 8.7%, p = 0.043), whereas the percentage of malapposed struts was similar (0.3 ± 0.5% vs. 0.7 ± 2.3%, p = 0.441). Neointimal hyperplasia (NIH) was more pronounced in the OL region (0.13 ± 0.04 vs. 0.24 ± 0.10 mm², p = 0.001). The OL and NOL segments showed comparable healing in terms of coverage and malapposition. However, NIH was more prominent in OL region. The long-term clinical implications of these findings needs further evaluation. The present study provides important insights for future development of BVS technology.

Contemporary Approach to Chronic Total Occlusion Interventions

PURPOSE OF REVIEW

Chronic total occlusion (CTO) poses one of the greatest technical challenges to interventional cardiologists. Despite recent advancements in techniques and clinical trials showing significant benefits of CTO percutaneous coronary interventions (PCI), the proportion of patients with untreated CTOs remains high. We therefore aim to perform a comprehensive review of the various techniques available, recent advancements, benefits, and complications associated with CTO PCI.

RECENT FINDINGS

Three randomized clinical trials examining the benefits of CTO PCI have recently been presented. Scoring systems have been developed to facilitate pre-procedural estimation of success and complications of CTO PCI. Technological enhancements in coronary wires and other interventional equipment along with dedicated training for CTO operators have improved the likelihood of successful recanalization of CTOs. CTO PCI has been shown to improve patient symptoms and quality of life. It is therefore important to have an in-depth knowledge of the various CTO techniques, appropriate equipment, and complications when performing these complex procedures. Clinicians should weigh the risks and benefits and choose the appropriate patient population who may benefit from revascularization.

Sex-Based Differences in Chronic Total Occlusion Management

ᅟ: Chronic total occlusions (CTOs) are an important and increasingly recognized subgroup of coronary lesions, documented in at least 30%, but up to 52% of patients with coronary artery disease (CAD) undergoing coronary angiography. Percutaneous coronary intervention (PCI) of these lesions is increasingly pursued, with excellent success rates. PURPOSE OF REVIEW: It is known that gender differences exist in the presentation of CAD, as well as in clinical outcomes after routine PCI; however, it is not well described how these differences pertain to management of CTOs. This review summarizes the available data regarding sex-based differences in CTO management and outcomes. RECENT FINDINGS: Women comprise approximately 20% of CTO registry and trial participants. As has been demonstrated in PCI studies, women comprise a minority of patients in CTO PCI registries and trials. Sex-based differences exist in complication rates, collateral formation, and outcomes and need further evaluation in future studies.

Epicardial collateral channel for retrograded recanalization of chronic total occlusion percutaneous coronary intervention: Predictors of failure and procedural outcome

OBJECTIVES

This study set out to identify significant lesion features of chronic total occlusion (CTO) that predict successful retrograde recanalization via epicardial collateral channels (CCs).

BACKGROUND

Epicardial CCs remain essential in retrograde percutaneous coronary intervention (PCI) of CTO. However, the unpredictability of success and occurrence of complications limit the application of epicardial CCs for retrograde PCI technique for CTO.

METHODS

103 retro-recanalization cases were analyzed using epicardial CCs with successful recanalization as an end point. Clinical and angiography data were collected.

RESULTS

The total success rate was 76.3%. Independent predictors associated with technical success included CCs tortuosity, side branch at CCs tortuosity, inadequate CCs Size and inadequate CCs exit location. Assigning a score of one for each variable, four levels of difficulty were obtained and formed the EPI-CTO score (Epicardial CTO). This score had significant predictive value for the likelihood of successful recanalization (AUC: 0.94, 95%CI: 0.89-0.98). Coronary and CCs perforation occurred in 6 and 10 cases respectively. Four cases including two coronary and two CCs perforations had tamponade that needed pericardiocentesis.

CONCLUSIONS

Using epicardial CCs for retrograde approach of CTO PCI is effective. Complication rate was acceptable. We found four independent predictors relative to procedure success.

Retrograde Approach is as Effective and Safe as Antegrade Approach in Contemporary Percutaneous Coronary Intervention for Chronic Total Occlusion: A Taiwan Single-Center Registry Study

BACKGROUND

In percutaneous coronary intervention (PCI) for chronic total occlusion (CTO), most experts regard the antegrade approach as the default initial strategy, reserving the retrograde approach for reattempts following antegrade failure. In this study, we aimed to compare the efficacy and safety between the antegrade and retrograde approaches in CTO PCI.

RESULTS

Between 2012 and 2013, patients that underwent 321 consecutive attempts by high-volume operators (> 75 total CTO PCI cases during the period) in a tertiary university-affiliated hospital were enrolled. The antegrade approach was used in 152 patients, and retrograde in 169 patients. The duration of occlusion was significantly longer and the J-CTO score higher in the retrograde group. Technical success was achieved in 148 patients of the antegrade group (97.4%), and 163 patients in the retrograde group (96.4%) (p = 0.75). A major procedural complication occurred in 3 patients of the antegrade group (2.0%) and in 6 patients of the retrograde group (3.6%) (p = 0.51). In-hospital major adverse cardiac events (MACE) rates (antegrade 0.7%, n = 152; retrograde 0.6%, n = 169) were comparable. The procedure and fluoroscopy times were significantly longer, with more radiation exposure and contrast medium consumption, in the retrograde group. In the retrograde group, similar success, procedural complication and in-hospital MACE rates were achieved in the 3 collateral subgroups.

CONCLUSIONS

In selected cases and with highly experienced operators, retrograde approach in CTO PCI is as effective and safe as antegrade approach at the expense of longer procedure time, more radiation exposure and contrast medium consumption. For retrograde approach, either septal, epicardial or AV groove collaterals can be used with similarly success, complication and in-hospital MACE rates.

Impact of Neutrophil to Lymphocyte Ratio (NLR) Index and Its Periprocedural Change (NLRΔ) for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusion

We assessed the association between neutrophil to lymphocyte ratio (NLR) and chronic coronary total occlusion (CTO), as well as clinical prognosis of percutaneous coronary intervention (PCI). Patients referred for elective coronary angiography for stable angina pectoris were enrolled, including a CTO (n = 160) and a non-CTO group (n = 160). Neutrophil to lymphocyte ratio on admission and post-PCI was measured, and NLR_Δ was defined as the change between the 2 values. Subgroup analysis was performed based on the value of NLR_Δ (≥0.5 vs <0.5). Clinical characteristics, angiographic data, and follow-up data were recorded. Compared with the non-CTO group, the total white blood cell count, neutrophil counts, and NLR were significantly higher in the CTO group. In the NLR_Δ ≥ 0.5 subgroup, the incidence of severe dissection, slow coronary flow, in-stent restenosis (ISR), and major adverse cardiac events (MACEs) was obviously higher. In multivariate analysis, NLR_Δ was independently and positively associated with higher risks of ISR and MACE. The NLR could be a potential predictor of CTO, and NLR_Δ is independently associated with the adverse clinical outcomes in patients who underwent PCI.

Procedural outcomes of chronic total occlusion percutaneous coronary intervention: a report from the NCDR (National Cardiovascular Data Registry)

OBJECTIVES

The aim of this study was to describe contemporary frequency, predictors, and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in the United States.

BACKGROUND

CTO PCI can provide significant clinical benefits, yet there is limited information on its success and safety in unselected patient populations.

METHODS

We analyzed the frequency and outcomes of CTO PCI compared with non-CTO PCI in elective patients, and of successful versus failed CTO PCI between July 1, 2009, and March 31, 2013, in the National Cardiovascular Data Registry CathPCI Registry. Generalized estimating equations logistic regression modeling was used to generate independent variables associated with procedural success and procedural complications.

RESULTS

During the study period, CTO PCI represented 3.8% of the total PCI volume for stable coronary artery disease (22,365 of 594,510). Overall, patients undergoing CTO PCI required greater contrast volume and longer fluoroscopy time and had lower procedural success (59% vs. 96%, p < 0.001) and higher major adverse cardiac event (1.6% vs. 0.8%, p < 0.001) rates than non-CTO PCI patients. On multivariable analysis, several parameters (including older age, current smoking, previous myocardial infarction, previous coronary artery bypass graft, previous peripheral arterial disease, previous cardiac arrest, right coronary artery CTO target vessel, and less operator experience) were associated with a lower likelihood of CTO PCI procedural success, whereas operators' annual CTO PCI volume was associated with improved success without a significant increase in major complications.

CONCLUSIONS

CTO PCI is currently performed infrequently in the United States for stable coronary artery disease and is associated with lower procedural success and higher complication rates compared with non-CTO PCI. Procedural success was associated with several patient factors and operator experience.

Intravascular Ultrasound Guided Percutaneous Coronary Intervention for Chronic Total Occlusion

Chronic total occlusion (CTO), a fascinating and dynamic niche in the realm of coronary artery disease, represents a major technical challenge for interventional cardiologists despite evolution of better guidewires, devices, experience and techniques. Effective wiring technique is the corner stone to success of percutaneous coronary intervention (PCI) in CTO. As a guide for guidewire crossing in CTO, coronary angiography is limited. On the other hand, intravascular ultrasound (IVUS) enhances the ability to identify coronary anatomy, the exact location of the guidewires within an artery, discriminating a true lumen from the false lumen before guidewire crossing. Some angiographic features have been suggested to be predictive of procedural failure, including blunt stump with a side branch at the site of occlusion. Novel use of IVUS can recognize the optimal entry point and evaluate if a guidewire properly penetrates the proximal cap of CTO.

The Hybrid Approach to Intervention of Chronic Total Occlusions

The “hybrid” approach to chronic total occlusion (CTO) percutaneous coronary intervention (PCI) was developed to provide guidance on optimal crossing strategy selection. Dual angiography remains the cornerstone of clinical decision making in CTO PCI. Four angiographic parameters are assessed: (a) morphology of the proximal cap (clear-cut or ambiguous); (b) oc-clusion length; (c) distal vessel size and presence of bifurcations beyond the distal cap; and (d) location and suitability of a retrograde con-duit (collateral channels or bypass grafts) for retrograde access. Antegrade wire escalation is favored for short (<20 mm) occlusions, usually escalating rapidly from a soft tapered-tip polymer-jacketed guidewire to a stiff polymer-jacketed or tapered-tip guidewire. Antegrade dissection/re-entry is favored in long (≥20 mm long) occlusions, try-ing to minimize the dissection length by re-entering into the distal true lumen immediately after the occlusion. Primary retro-grade approach is preferred for lesions with an ambiguous proximal cap, poor distal target, good interventional collaterals, and heavy calcification, as well as chronic kidney disease. The “hybrid” approach advocates early change between strategies to enable CTO crossing in the most efficacious, efficient, and safe way. Several early studies are demonstrating high success and low complication rates with use of the “hybrid” approach, supporting its expanding use in CTO PCI. .

The impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcomes

A meta-analysis by Hoebers et al. reported that successful chronic total occlusion (CTO) recanalization resulted in an increase in left ventricular (LV) ejection fraction by 4.44% (P<0.01) and a reduction in LV end-diastolic volume by 6.14 mL/m(2) during follow-up as compared with baseline, suggesting beneficial LV remodeling. These findings are important as the myocardium supplied by a CTO frequently has sustained irreversible injury and further support the clinical benefits of CTO interventions.

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.

Meta-analysis of clinical outcomes of patients who underwent percutaneous coronary interventions for chronic total occlusions

Successful percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has been associated with clinical benefit. There are no randomized controlled trials on long-term clinical outcomes after CTO PCI, limiting the available evidence to observational cohort studies. We sought to perform a weighted meta-analysis of the long-term outcomes of successful versus failed CTO PCI. A total of 25 studies, published from 1990 to 2014, with 28,486 patients (29,315 CTO PCI procedures) were included. We analyzed data on mortality, subsequent coronary artery bypass grafting (CABG), myocardial infarction, major adverse cardiac events, angina pectoris, stroke, and target vessel revascularization using random-effects models. Procedural success was 71% (range 51% to 87%). During a weighted mean follow-up of 3.11 years, compared with unsuccessful, successful CTO PCI was associated with lower mortality (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.43 to 0.63), less residual angina (OR 0.38, 95% CI 0.24 to 0.60), lower risk for stroke (OR 0.72, 95% CI 0.60 to 0.88), less need for subsequent coronary artery bypass grafting (OR 0.18, 95% CI 0.14 to 0.22), and lower risk for major adverse cardiac events (0.59, 95% CI 0.44 to 0.79). There was no difference in the incidence of target vessel revascularization (OR 0.66, 95% CI 0.36 to 1.23) or myocardial infarction (OR 0.73, 95% CI 0.52 to 1.03). Outcomes were similar in patients who underwent balloon angioplasty only or stenting with bare metal or drug-eluting stents. Compared with failed procedures, successful CTO PCIs are associated with a lower risk of death, stroke, and coronary artery bypass grafting and less recurrent angina pectoris.

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.

Short-term effect of percutaneous recanalization of chronic total occlusions on QT dispersion and heart rate variability parameters

Background

QT dispersion (QTd), which is a measure of inhomogeneity of myocardial repolarization, increases following impaired myocardial perfusion. Its prolongation may provide a suitable substrate for life-threatening ventricular arrhythmias. We investigated the changes in QTd and heart rate variability (HRV) parameters after successful coronary artery revascularization in a patient with chronic total occlusions (CTO).

Material/Methods

This study included 139 successfully revascularized CTO patients (118 men, 21 women, mean age 58.3±9.6 years). QTd was measured from a 12-lead electrocardiogram and was defined as the difference between maximum and minimum QT interval. HRV analyses of all subjects were obtained. Frequency domain (LF: HF) and time domain (SDNN, pNN50, and rMSSD) parameters were analyzed. QT intervals were also corrected for heart rate using Bazett’s formula, and the corrected QT interval dispersion (QTcd) was then calculated. All measurements were made before and after percutaneous coronary intervention (PCI).

Results

Both QTd and QTcd showed significant improvement following successful revascularization of CTO (55.83±14.79 to 38.87±11.69; p<0.001 and 61.02±16.28 to 42.92±13.41; p<0.001). The revascularization of LAD (n=38), Cx (n=28) and RCA (n=73) resulted in decrease in HRV indices, including SDDN, rMSSD, and pNN50, but none of the variables reached statistical significance.

Conclusions

Successful revascularization of CTO may result in improvement in regional heterogeneity of myocardial repolarization, evidenced as decreased QTcd after the PCI. The revascularization in CTO lesions does not seem to have a significant impact on HRV.

Outcomes after complete versus incomplete revascularization of patients with multivessel coronary artery disease: a meta-analysis of 89,883 patients enrolled in randomized clinical trials and observational studies

OBJECTIVES

This study sought to perform a systematic review and meta-analysis of studies comparing complete revascularization (CR) versus incomplete revascularization (IR) in patients with multivessel coronary artery disease.

BACKGROUND

There are conflicting data regarding the benefits of CR in patients with multivessel coronary artery disease.

METHODS

We identified observational studies and subgroup analysis of randomized clinical trials (RCT) published in PubMed from 1970 through September 2012 using the following keywords: "percutaneous coronary intervention" (PCI); "coronary artery bypass graft" (CABG); "complete revascularization"; and "incomplete revascularization." Main outcome measures were total mortality, myocardial infarction, and repeat revascularization procedures.

RESULTS

We identified 35 studies including 89,883 patients, of whom 45,417 (50.5%) received CR and 44,466 (49.5%) received IR. IR was more common after PCI than after CABG (56% vs. 25%; p < 0.001). Relative to IR, CR was associated with lower long-term mortality (risk ratio [RR]: 0.71, 95% confidence interval [CI]: 0.65 to 0.77; p < 0.001), myocardial infarction (RR: 0.78, 95% CI: 0.68 to 0.90; p = 0.001), and repeat coronary revascularization (RR: 0.74, 95% CI: 0.65 to 0.83; p < 0.001). The mortality benefit associated with CR was consistent across studies irrespective of revascularization modality (CABG: RR: 0.70, 95% CI: 0.61 to 0.80; p < 0.001; and PCI: RR: 0.72, 95% CI: 0.64 to 0.81; p < 0.001) and definition of CR (anatomic definition: RR: 0.73, 95% CI: 0.67 to 0.79; p < 0.001; and nonanatomic definition: RR: 0.57, 95% CI: 0.36 to 0.89; p = 0.014).

CONCLUSIONS

CR is achieved more commonly with CABG than with PCI. Among patients with multivessel coronary artery disease, CR may be the optimal revascularization strategy.