Angiographic predictors of success in antegrade approach of Chronic Total Occlusion interventions in a South Indian population in the contemporary era

Overview of Contemporary Chronic Total Occlusion Percutaneous Coronary Intervention Techniques: A Narrative Systematic Review

BACKGROUND

Despite the abundance of coronary chronic total occlusions (CTO) percutaneous coronary intervention (PCI) studies, the literature is not easy to digest for both general PCI operators and CTO PCI specialists because of the many varied terms used for approaches and inconsistency in terminology. This inconsistency makes it challenging to understand the advantages and disadvantages of these different approaches and, most importantly, their downstream clinical outcomes. Accordingly, we conducted a systematic review of all published studies on CTO PCI to describe techniques and algorithms used in the last decade to provide an overview on the efficacy and safety of contemporary CTO PCI techniques.

METHODS

We performed a comprehensive search of the PubMed, EMBASE, and the Cochrane library databases for manuscripts about PCI of CTOs. We included studies published between the years 2005 and 2019. We categorized studies into those using a single approach (antegrade, retrograde) and those with a prespecified algorithm (ie, hybrid approach).

RESULTS

Fifty-five observational studies including 28,907 patients who underwent CTO were included in this review. CTO PCI generally carries low risk of major procedural complications, with angiographic success rates being higher in studies that used an algorithmic vs single technical approach.

CONCLUSIONS

This systematic review highlights the wide variation in definitions and practices in CTO PCI and calls for standardization in terminology and practice.

Real world perspective of coronary chronic total occlusion in third world countries: A tertiary care centre study from northern India

OBJECTIVES

The aim of this study is to determine the prevalence, clinical characteristics, angiographic profile and predictors of outcome for percutaneous coronary interventions (PCI) of coronary chronic total occlusions (CTO) in a tertiary referral centre of north India.

BACKGROUND

There is no data on the prevalence and very few reports on clinical characteristics, angiographic profile and outcome of PCI in CTO from India.

METHODS

Retrospective analysis was done for the data of 12,020 patients undergoing coronary angiography (CAG) between January 2018 to January 2019 at our centre. Detailed baseline clinical, angiographic and revascularization data was collected. Outcome of CTO PCI was also noted. All baseline parameters were analysed for predicting the outcome of CTO PCI.

RESULTS

CTO was identified in 16.3% (1968) patients undergoing CAG and in 24.4% of patients with hemodynamically significant CAD. CTO was predominantly found in LAD (48%) followed by RCA (42.9%) and LCx (25.3%) arterial distribution. Mean JCTO score was 1.93 ± 0.7. PCI as a management strategy was adopted in 456 of 1968 patients (23.1%) and was successful in 340 of 456 (74.6%) of patients. Almost all CTO PCI were attempted by an antegrade approach only. Increasing age, male sex, CTO in LCx arterial distribution and higher J CTO score were associated with poorer outcome in CTO PCI.

CONCLUSIONS

CTO's are commonly encountered during CAG procedures. In patients undergoing CTO PCI, a fair success rate can be achieved in a high volume experienced centre.

Coronary Angiography Characteristics as Predictor of Successful Chronic Total Occlusion Recanalization

Although remarkable progress in percutaneous coronary intervention (PCI) has been achieved over the last decade, the success rate of chronic total occlusion (CTO) recanalization varies greatly. Coronary angiography characteristics may affect the success rate of CTO recanalization. This study sought to establish a scoring model to predict successful CTO recanalization based on coronary angiography characteristics. We analyze 287 angiography data from patients who underwent elective PCI. Angiography characteristics being measured were lesion location, blunt stump, calcification, ostial lesion, bridging collateral, bending, side branch, tortuosity, previous stent attempt, and lesion length of >20 mm. Data were analyzed using SPSS 25.0. Multivariate analysis shows that side branch lesion ( p  = 0.000), proximal vessels tortuosity ( p  = 0.015), calcified lesion ( p  = 0.000), lesion length of >20 mm ( p  = 0.000), and blunt stump ( p  = 0.000) can predict the successful PCI in the CTO. ROC curve analysis of the score ability to predict successful PCI in the CTO showed area under curve of 0.89 (confidence interval 95%), the cutoff point of ≤2 with a sensitivity of 93.33%, and specificity of 88.23%. We concluded that the five angiography characteristics that strongly associate with successful PCI in the CTO are calcified lesion, blunt stump, lesion length >20 mm, proximal vessel tortuosity, and side branch lesion. This score may help cardiologists to predict the success probability of PCI in the CTO.

Procedural and follow-up clinical outcomes after chronic total occlusion revascularization: Data from an Indian public hospital

BACKGROUND

Chronic total occlusion (CTO) continues to be challenging lesion subset for percutaneous intervention. Last decade has seen tremendous increase in percutaneous coronary intervention (PCI) in this subset owing to improved understanding of the anatomy and enhanced skillset with availability of dedicated hardware. We sought to study the outcomes of CTO PCI in an Indian public hospital.

METHODS

This was a single-center non-randomized descriptive follow-up study on CTO PCI. The end-points were procedural success, immediate, and late adverse cardiovascular events [major adverse cardiac event (MACE)] and change in angina and left ventricular function at follow-up.

RESULTS

A total 389 CTO lesions were treated with a success rate of 87% (339/389). The mean Japanese chronic total occlusion (J-CTO) score was 1.78 ± 0.12 (mean ± standard deviation). Multivariate analysis of different angiographic components of J-CTO score identified tortuosity (p = 0.001), calcifications (p ≤ 0.001), and blunt stump (p = 0.007) as independent predictors of procedural failure. The periprocedural mortality was less than 1%, and the non-life threatening complications were about 4%. The MACE rate was significantly higher in the procedural failure group (60%) than in the procedural success group (5.3%, p < 0.001). An increase in left ventricular ejection fraction (LVEF) was noted following successful CTO PCI after complete revascularization.

CONCLUSIONS

The success rates for CTO PCI in this registry were about 87%. Immediate and long-term clinical outcomes were better with lower MACE (5%) after a successful procedure. A key outcome variable included an increase in LVEF among patients after a successful CTO PCI. The overall periprocedural complications were about 5.5%, but majority were non-life threatening.

Diagnostic accuracy of multi-slice computed tomography in identifying lesion characteristics in coronary total occlusion

We performed this study to compare the sensitivity and specificity of multi-slice computed tomography (MSCT) to coronary angiography (CA) in detecting coronary total occlusion (CTO) lesion characteristics. Moreover, we analyzed the association between these characteristics and the risk of revascularization failure. Fifty patients with confirmed CTO diagnosis were tried for revascularization using the antegrade (all 50) or retrograde (in failed nine antegrade interventions) approaches. Each patient underwent CA and MSCT before the intervention and data from both modalities were compared using the SPSS software. Successful revascularization occurred in 36 (72%) and 6 (66.7%) patients of the antegrade and retrograde groups, respectively. Compared to CA, MSCT exhibited high sensitivity in detecting CTO segment calcification (100%), size of the affected vessel (100%, area under the curve [AUC] = 0.82), distal filling of the affected segment (97.7%) and side-branching at the CTO segment (93.3%). However, it had lower sensitivity in detecting collaterals (75%) and the length of the affected segment (87.5%, AUC = 0.77). According to MSCT data, increased occlusion length > 18 mm (p = 0.01), atherosclerotic vessel wall (p = 0.02), small distal vessel size ≤ 2.75 mm (p = 0.002), proximal side-branching (p = 0.01) and calcification of the proximal cap (p = 0.007) or distal stump (p = 0.01) were associated with an increased risk of revascularization failure. MSCT exhibited high sensitivity in identifying several CTO lesion characteristics, such as lesional calcification and size of the affected vessel. However, further research is needed to improve the diagnostic accuracy of this modality and define the predictors of revascularization failure in CTO patients.

Predictors of success in percutaneous Coronary intervention for chronic total occlusion

We performed a retrospective analysis of 146 chronic total occlusion CTO patients to evaluate the antecedents of success and failure in CTO – Percutaneous Coronary Intervention (PCI) in Indian patients. The study aimed to identify the technical success rate, analyse immediate patient outcomes, and understand the factors impacting the successful outcomes. Our results showed that J-CTO (Multicenter CTO Registry of Japan) scores correlate well with the success rates of CTO-PCI and two most important factors deciding failure are lesion length more than 20 mm and lesions with calcification. Most important step to success of CTO is wiring, once wire crosses the segment, success rates of the procedure is around 97%. The wire escalation strategy has to be modified once the initial soft (polymer) wire fails, it’s reasonable to use high tip load wire like conquest pro without the use of intermediate wires (except in presence of tortuosity). At 1 year follow up of these patients, there was a statistically significant drop in angina class and major adverse cardiac event rates in the successful CTO group.