Percutaneous Coronary Intervention Versus Medical Therapy for Chronic Total Occlusion of Coronary Arteries: A Systematic Review and Meta-Analysis

Incidence of ventricular arrhythmias in patients with chronic total coronary occlusion: Results of the VACTOR study

Background

A chronic total coronary occlusion (CTO) is associated with ventricular arrhythmias (VA) in patients with an implantable cardioverter-defibrillator (ICD). Limited data is available on the incidence of VA in CTO patients without an ICD.

Objectives

To investigate the incidence of sustained VA in CTO patients after successful CTO revascularization and in patients with untreated CTO or failed CTO revascularization.

Methods

Prospective, multicenter observational pilot study including CTO patients who were not eligible for an ICD and had a left ventricular ejection fraction >35 %. We enrolled patients with a successful CTO revascularization (group A) and patients with untreated CTO or failed CTO revascularization (group B). All patients received an implantable loop recorder with remote monitoring. The primary endpoint was sustained VA.

Results

Ninety patients were enrolled (mean age 63 ± 10 years, 83.3 % man, mean LVEF 55 ± 8 %). Group A (n = 45) had a higher prevalence of CTO in the left anterior descending artery in comparison to group B (n = 45) (28.9 % versus 4.4 %, P = 0.002). Other baseline characteristics were similar. During a median follow-up time of 26 months (IQR, 19-35), five patients (5.6 %) had a sustained VA. There was no difference in the incidence of sustained VA between groups (3-year cumulative event rate: 8.8 % (group A) versus 4.5 % (Group B), log-rank P = 0.71).

Conclusion

Patients with an CTO, who do not qualify for an ICD, have a substantial risk of sustained VA. In our study the incidence was not different between patients with revascularized and those with untreated CTO.

Effect of cytochrome P450 2C19 (CYP2C19) gene polymorphism and clopidogrel reactivity on long term prognosis of patients with coronary heart disease after PCI

Objective

To investigate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity and its association with long-term clinical outcome in patients with coronary heart disease (CHD) undergoing percutaneous coronary intervention (PCI).

Methods

In total, 675 patients were enrolled. Based on the platelet inhibition rate, patients were categorized into two groups: clopidogrel low responsiveness (CLR) and normal clopidogrel responsiveness (NCR). The CLR group was divided into ticagrelor and clopidogrel group based on the antiplatelet drugs used in the follow-up treatment. Patients were classified into three groups (normal metabolizer, intermediate metabolizer, and poor metabolizer) based on the CYP2C19 genotype. We aimed to evaluate the impact of CYP2C19 gene polymorphism on clopidogrel reactivity. The cumulative rates of 12-month all-cause deaths, major adverse cardiovascular events (MACCEs), and bleeding events were calculated.

Results

CLR was observed in 44.4% of the overall population. Significant differences were observed in the platelet inhibition rate of clopidogrel among the three metabolic genotypes (P < 0.05). At the 12-month follow-up, 13 patients (1.9%) died and 96 patients (14.2%) experienced MACCEs. Patients with CLR (9.6% vs. 11.7% vs. 22.1%, P < 0.05) or poor metabolizer (10.7% vs. 16.4% vs. 22.6%, P = 0.026) experienced a higher rate of MACCEs. A MACCEs risk score between zero and two was calculated. The highest incidence of MACCEs significantly increased with the 2-positive results, and the area under the curve (AUC) was 0.712 (95% CI: 0.650-0.774, P < 0.05). There was no significant difference between the group with a score of one and the occurrence of MACCEs (P > 0.05).

Conclusions

Low response to clopidogrel in CHD patients is correlated with CYP2C19 gene polymorphism. CYP2C19 genotyping combined with platelet reactivity is an independent predictor of 12-months MACCEs in patients with clopidogrel treatment after PCI, which is better than either test alone.

Dilemmas in cardiology: when to recanalize a chronic total occlusion

The decision whether or not to recanalize a chronic total occlusion (CTO) of a coronary artery is truly a dilemma for the cardiologist. The procedure is in fact complex, with a non-negligible rate of complications and with a probability of success lower than that of non-obstructive lesions. The analysis of the data available in the literature, with the significant discrepancy between the results of the randomized studies and the observational studies, does not currently allow conclusive statements on the role of the percutaneous coronary interventions in CTO. It is therefore essential to incorporate clinical, anatomical and procedural elements into the decision-making algorithm. While awaiting new randomized clinical trials of greater dimensions and better methodology, a careful selection of patients is certainly essential, limiting the procedure to those who are symptomatic or who have a high ischaemic burden and excluding those who have no evidence of vitality, without which it is not legitimate to expect any benefit from the intervention. Finally, the presence of the collateral circulation does not in itself appear to be an element that should have a significant decision-making role.

The Role of Multimodality Imaging for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusions

Background

Percutaneous coronary intervention (PCI) of Chronic total occlusions (CTOs) has been traditionally considered a challenging procedure, with a lower success rate and a higher incidence of complications compared to non-CTO-PCI. An accurate and comprehensive evaluation of potential candidates for CTO-PCI is of great importance. Indeed, assessment of myocardial viability, left ventricular function, individual risk profile and coronary lesion complexity as well as detection of inducible ischemia are key information that should be integrated for a shared treatment decision and interventional strategy planning. In this regard, multimodality imaging can provide combined data that can be very useful for the decision-making algorithm and for planning percutaneous CTO recanalization.

Aims

The purpose of this article is to appraise the value and limitations of several non-invasive imaging tools to provide relevant information about the anatomical characteristics and functional impact of CTOs that may be useful for the pre-procedural assessment and follow-up of candidates for CTO-PCI. They include echocardiography, coronary computed tomography angiography (CCTA), nuclear imaging, and cardiac magnetic resonance (CMR). As an example, CCTA can accurately delineate CTO location and length, distal coronary bed, vessel tortuosity and calcifications that can predict PCI success, whereas stress CMR, nuclear imaging and stress-CT can provide functional evaluation in terms of myocardial ischemia and viability and perfusion defect extension.

A comparison of long-term clinical outcomes between percutaneous coronary intervention (PCI) and medical therapy in patients with chronic total occlusion in noninfarct-related artery after PCI of acute myocardial infarction

BACKGROUND

Chronic total occlusion (CTO) in a noninfarct-related artery (IRA) is one of the risk factors for mortality after acute myocardial infarction (AMI). However, there are limited data comparing the long-term outcomes of patients undergoing percutaneous coronary intervention (PCI) with patients having medical therapy (MT) in CTO lesion after AMI PCI.

METHODS

We retrospectively enrolled 330 patients (successful CTO PCI in 166 patients, failed CTO PCI in 32 patients, MT in 132 patients) with non-IRA CTO from a total of 4372 patients who underwent PCI after AMI in our center. Propensity score matching (PSM) was used to adjust for baseline differences.

RESULTS

The primary analysis is based on the intention-to-treat population. During a median follow-up period of 946 days, patients in the PCI group (n = 198) had significantly higher cardiac death-free survival (96.6% vs. 82.8%, p = .004) compared with patients in MT group (n = 132). However, no significant difference in the occurrence of cardiac death was observed after PSM. The analysis based on the per-protocol population demonstrated significantly higher cardiac death-free survival in the successful CTO PCI group (n = 166) compared with the occluded CTO group (n = 164) both before and after PSM. In subgroup analysis, successful CTO PCI was associated with less cardiac death in patients over 65 years old, with LVEF < 50%, left anterior descending (LAD) IRA, and non-LAD CTO lesion compared with occluded CTO group.

CONCLUSIONS

Patients undergoing successful revascularization of non-IRA CTO after AMI might have a better long-term prognosis. Moreover, patients with LVEF < 50% may benefit from successful non-IRA CTO PCI after AMI.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Clinical outcomes of percutaneous coronary intervention for chronic total occlusion in prior coronary artery bypass grafting patients

OBJECTIVE

To compare the clinical characteristics and outcomes in patients with stable angina who have undergone chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in native arteries with or without prior coronary artery bypass grafting (CABG) surgery in a national cohort.

BACKGROUND

There are limited data on outcomes of patients presenting with stable angina undergoing CTO PCI with previous CABG.

METHODS

We identified 20,081 patients with stable angina who underwent CTO PCI between 2007-2014 in the British Cardiovascular Intervention Society database. Clinical, demographical, procedural and outcome data were analyzed in two groups; group 1-CTO PCI in native arteries without prior CABG (n = 16,848), group 2-CTO PCI in native arteries with prior CABG (n = 3,233).

RESULTS

Patients in group 2 were older, had more comorbidities and higher prevalence of severe left ventricular systolic dysfunction. Following multivariable analysis, no significant difference in mortality was observed during index hospital admission (OR:1.33, CI 0.64-2.78, p = .44), at 30-days (OR: 1.28, CI 0.79-2.06, p = .31) and 1 year (OR:1.02, CI 0.87-1.29, p = .87). Odds of in-hospital major adverse cardiovascular events (MACE) (OR:1.01, CI 0.69-1.49, p = .95) and procedural complications (OR:1.02, CI 0.88-1.18, p = .81) were similar between two groups but procedural success rate was lower in group 2 (OR: 0.34, CI 0.31-0.39, p < .001). The adjusted risk of target vessel revascularization (TVR) remained similar between the two groups at 30-days (OR:0.68, CI 0.40-1.16, P-0.16) and at 1 year (OR:1.01, CI 0.83-1.22, P-0.95).

CONCLUSION

Patients with prior CABG presenting with stable angina and treated with CTO PCI in native arteries had more co-morbid illnesses but once these differences were adjusted for, prior CABG did not independently confer additional risk of mortality, MACE or TVR.

Outcomes of percutaneous coronary intervention for chronic total occlusions in the elderly: A systematic review and meta-analysis

Objective

This study aimed to compare outcomes of percutaneous coronary intervention (PCI) for chronic total occlusions (CTO) in the elderly (≥75 years) versus nonelderly and assess the impact of successful CTO‐PCI in the elderly.

Methods

PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases were searched up to October 1, 2020. Mortality rates and major adverse cardiac events (MACE) were compared between elderly and nonelderly patients and successful versus failed CTO‐PCI in the elderly.

Results

Eight studies were included. Meta‐analysis indicated no statistically significant difference in the risk of in‐hospital mortality (RR: 1.97 95% CI: 0.78, 4.96 I² = 0% p = .15) but higher tendency of in‐hospital MACE (RR: 2.30 95% CI: 0.99, 5.35 I² = 49% p = .05) in the elderly group. Risk of long‐term mortality (RR: 3.79 95% CI: 2.84, 5.04 I² = 41% p < .00001) and long‐term MACE (RR: 1.53 95% CI: 1.14, 2.04 I² = 80% p = .004) were significantly increased in the elderly versus nonelderly. Elderly patients had a significantly reduced odds of successful PCI as compared to nonelderly patients (OR: 0.63 95% CI: 0.54, 0.73 I² = 1% p < .00001). Successful CTO‐PCI was associated with reduction in long‐term mortality (HR: 0.51 95% CI: 0.34, 0.77 I² = 27% p = .001) and MACE (HR: 0.60 95% CI: 0.37, 0.97 I² = 53% p = .04) as compared to failed PCI in elderly.

Conclusions

Elderly patients may have a tendency of higher in‐hospital MACE with significantly increased long‐term mortality and MACE after CTO‐PCI. The success of PCI is significantly lower in the elderly. In elderly patients with successful PCI, the risk of long‐term mortality and MACE is significantly reduced.

Percutaneous Coronary Intervention for Chronic Total Occlusion

Treatment of coronary chronic total occlusions represents one of the major challenges in the field of interventional cardiology. This is due to the complexity of these procedures and to the relatively higher risk of complications. In recent years, the development of innovative techniques and the evolution of materials have produced significant progress in this field. Better procedural outcomes have been achieved, with fewer complications. This article highlights the most recent scientific evidence and techniques, with the intention to guide interventional cardiologists in optimal patient selection and procedure choice.

Vulnerability for ventricular arrhythmias in patients with chronic coronary total occlusion

INTRODUCTION

The presence of a chronic total occlusion (CTO) is associated with an increased risk of ventricular arrhythmias.

AREAS COVERED

This review provides an overview of the relationship between CTO and ventricular arrhythmias, arrhythmogenic mechanisms, and the effect of revascularization.

EXPERT OPINION

Studies in recipients of an implantable cardioverter-defibrillator (ICD) have shown that a CTO is an independent predictor of appropriate ICD therapy. The myocardial territory supplied by a CTO is a pro-arrhythmogenic milieu characterized by scar tissue, large scar border zone, hibernating myocardium, residual ischemia despite collaterals, areas of slow conduction, and heterogeneity in repolarization. Restoring coronary flow by revascularization might be associated with electrical homogenization as reflected by a decrease in QT(c) dispersion, decrease in T wave peak-to-end interval, reduction of late potentials, and decrease in scar border zone area. Future research should explore whether CTO revascularization results in a lower burden of ventricular arrhythmias. Furthermore, risk stratification of CTO patients without severe LV dysfunction is interesting to identify potential ICD candidates. Potential tools for risk stratification are the use of electrocardiographic parameters, body surface mapping, electrophysiological study, and close rhythm monitoring using an insertable cardiac monitor.