Ventricular Arrhythmias Among Implantable Cardioverter-Defibrillator Recipients for Primary Prevention

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.

Ventricular tachycardic storm with a chronic total coronary artery occlusion treated with percutaneous coronary intervention

A 66-year-old man with a history of coronary artery disease was evaluated due to ventricular tachycardic (VT) storm. The patient continued to have frequent recurrences of VT despite treatment with amiodarone and lidocaine. Since the ventricular arrhythmia could be related to myocardial ischemia related to a chronic total occlusion (CTO) of the right coronary artery, the patient underwent successful percutaneous coronary intervention of the CTO, followed by implantable cardioverter defibrillator implantation. He had no further episodes of VT during his hospital stay. After 9 months of follow-up, he had no further chest pain or clinically apparent recurrent ischemia. Interrogation of his defibrillator has shown brief nonsustained episodes of ventricular tachycardia, but the patient has not required delivery of a shock. The temporal association between treatment of the CTO and resolution of the VT, as well as the lack of recurrence of sustained VT, suggest a causative link between underlying ischemia produced by a chronically occluded coronary artery and provocation of VT and lend supportive evidence to this treatment approach.

Meta-analysis on the impact of percutaneous coronary intervention of chronic total occlusions on left ventricular function and clinical outcome

BACKGROUND

Percutaneous coronary intervention (PCI) of chronic total occlusions (CTOs) may have a beneficial effect on survival through a better-preserved or improved LVEF. Current literature consists of small observational studies therefore we performed a weighted meta-analysis on the impact of revascularization of CTOs on left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV) and long-term mortality.

METHODS

We conducted a meta-analysis evaluating LVEF before and after CTO PCI and long-term mortality. No language or time restrictions were applied. References from the identified articles and reviews were examined to find additional relevant manuscripts.

RESULTS

Of the 812 citations, 34 studies performed between 1987-2014 in 2243 patients were eligible for LVEF and 27 studies performed between 1990-2013 in 11,085 patients with success and 4347 patients that failed CTO PCI were eligible for long-term mortality. After successful CTO PCI, LVEF increased with 4.44% (95% CI: 3.52-5.35, p<0.01) compared to baseline. In a small cohort of ~70 patients, no significant difference in LVEF was observed after non-successful CTO PCI or reocclusion. Additionally, 8 studies reported the change in left ventricular end-diastolic volume (LVEDV) in a total of 412 patients. LVEDV decreased with 6.14 ml/m(2) (95% CI: -9.31 to -2.97, p<0.01). Successful CTO PCI was also associated with reduced mortality in comparison with failed CTO PCI (OR: 0.52, 95% CI: 0.43-0.62, p-value<0.01).

CONCLUSIONS

The current meta-analysis revealed that successful recanalization of a CTO resulted in an overall improvement of 4.44% absolute LVEF points, reduced adverse remodeling and an improvement of survival (OR: 0.52).

Impact of a chronic total occlusion in an infarct-related artery on the long-term outcome of ventricular tachycardia ablation

INTRODUCTION

In patients with a prior myocardial infarction (MI), angiographic predictors of ventricular tachycardia (VT) recurrence after ablation are lacking. Recently, a proarrhythmic effect of a chronic total occlusion (CTO) in a coronary artery has been suggested.

METHODS AND RESULTS

A total of 191 patients with prior MI were referred to our Hospital between 2010 and June 2013 for a first ablation of VT. Of these, 84 patients (44%) with stable coronary artery disease that underwent a coronary angiography during the index hospitalization were included in this study. A CTO in an infarct-related artery (IRA-CTO) was present in 47 patients (56%). Patients with and without IRA-CTO did not differ in terms of comorbidities, severity of heart failure, presentation of VT or acute outcome of ablation, that was completely successful in 93% of cases. At electroanatomic mapping, IRA-CTO was associated with greater scar and especially with greater area of border zone (34 cm(2) vs. 19 cm(2) , P = 0.001). Median follow-up was 19 months (IQR 18). At follow-up, patients with IRA-CTO had a significantly higher rate of VT recurrence (47% vs. 16%, P = 0.003). At multivariate analysis, IRA-CTO resulted to be an independent predictor of VT recurrence after ablation (HR 4.05, P = 0.004).

CONCLUSIONS

IRA-CTO is an independent predictor of VT recurrence after ablation and identifies a subgroup of patients with high recurrence rate despite a successful procedure. IRA-CTO is associated with greater scars and border zone area; however, this association does not completely justify its proarrhythmic effect.

Evidence for Benefit of Percutaneous Coronary Intervention for Chronically Occluded Coronary Arteries (CTO) - Clinical and Health Economic Outcomes

Percutaneous revascularisation of a coronary chronic total occlusion (CTO) remains one of the technical frontiers of interventional cardiology. CTOs are common, and yet intervention is only attempted in 10 % of cases. CTO procedures are perceived to be technically challenging, lengthy, associated with significant risk and have only limited data to support the practise. Recent technical advances have dramatically increased the success rate, shortened procedural time and improved clinical outcomes. The aim of this article is to critically examine the data that supports CTO intervention, including specifically an appraisal of procedural safety, benefit and overall cost effectiveness.

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.

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.

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.

[Ventricular tachycardia in postinfarction patients and coronary heart disease. Treatment and prognostic significance]

Patients with coronary heart disease are subject to an increased risk for sudden cardiac death (SCD). Within the first 30-90 days after the myocardial infarct the risk is particularly high. In times of implantable cardioverter-defibrillator (ICD) on the one hand and the ability to bridge high-risk periods with e. g. wearable defibrillator vests on the other, adequate risk stratification is essential. Currently, the main parameter for this is the left ventricular ejection fraction (LVEF). However, risk stratification by measurement of the LVEF has severe limitations, especially since the majority of patients suffering from SCD have a normal LVEF. Various other methods like ventricular ectopy, signal-averaged ECG, QRS width, microvolt T-wave alternans and programmed ventricular stimulation have been previously evaluated. None of these methods alone or in combination with a left ventricular function assessment was capable of improving the predictability of arrhythmic events significantly. Considering the multiple mechanisms that can lead to SCD, a single risk stratifier seems unrealistic. However, patients with chronic total occlusion of a coronary artery and residual or provocable ischemia have an increased risk for SCD. Therefore a combination of clinical and angiographic parameters seems reasonable. Advanced echocardiographic parameters e.g. mechanical dispersion could be used on a complementary role.

Validation of the J-chronic total occlusion score for chronic total occlusion percutaneous coronary intervention in an independent contemporary cohort

BACKGROUND

Chronic total occlusion (CTO) recanalization is a complex and technically challenging procedure. The J-CTO score has been proposed to stratify case complexity and procedural success rates. However, the score has never been tested outside the setting of the original study. Moreover, its predictive value when using a hybrid antegrade or retrograde approach is unknown. We investigated the performance of the J-CTO score for predicting procedure complexity and success in an independent contemporary cohort.

METHODS AND RESULTS

A total of 209 consecutive patients who underwent CTO recanalization by a high-volume operator were included. Clinical and angiographic data were prospectively collected. The J-CTO score was applied for each patient, and discrimination and calibration were evaluated in the whole cohort, and according to the approach (antegrade 47% and retrograde 53%). Clinical and angiographic differences were noted between the original and studied cohort. The mean J-CTO score was 2.18±1.26, and successful guidewire crossing within 30 minutes and final angiographic success were 44.5% and 90.4%, respectively. The J-CTO score demonstrated good discrimination (c statistic, >0.70) and calibration (Hosmer-Lemeshow P>0.1) in the whole cohort and for antegrade and retrograde approaches. However, the final success rate was not associated with the J-CTO score.

CONCLUSIONS

In this independent cohort, the J-CTO score showed good discriminatory and calibration capacity for guidewire CTO crossing within 30 minutes but it does not for final success rate. The J-CTO score helps to predict complexity of CTO recanalization, and the simplicity of the score supports the widespread use as a clinical tool.