Catheter ablation of ventricular tachycardia in the setting of electrical storm after revascularization of a chronic total occlusion of the right coronary artery: An uncommon presentation of reperfusion arrhythmia

Relevance of Chronic Total Occlusion for Outcome of Ventricular Tachycardia Ablation in Ischemic Cardiomyopathy

Background

Catheter ablation of ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) is an effective tool to prevent VT recurrences. Chronic total occlusion (CTO) represents a clinically relevant entity in ICM patients and is an independent predictor of ventricular arrhythmia and mortality. The effects of CTO on the outcome of VT ablation are not well-studied.

Objective

This analysis aimed to identify the impact of CTO, revascularized, or not revascularized, on the outcome of VT ablation.

Methods and Results

Of 385 consecutive subjects with ICM-VT who underwent catheter VT ablation for monomorphic VT at Heart Center Leipzig between 2008 and 2017, 108 patients without CTO and 191 patients with CTO were included in the analysis. Within a median follow-up time of 557 days (IQR 149, 1095), VT recurred in 77 (40%) patients in the CTO and 40 (37.0%) in the non-CTO cohort (p = 0.62). In a multivariable model, a 10% stepwise change in LVEF as well as ICD on admission was associated with VT recurrence (HR_adj 1.82, 95% CI 1.04–3.18 and HR_adj 1.35, 95% CI 1.23–1.61, respectively). Of the CTO cohort before ablation, 45% had received revascularization, which was independently associated with a higher risk for VT recurrence (HR 2.12, 95% CI 1.35–3.34) as compared to nonrevascularized CTO.

Conclusion

In ICM patients with and without CTO, VT ablation was associated with equal effectiveness with regard to VT recurrence. However, in revascularized CTO patients, the risk of recurrence of VT after ablation was significantly increased.

Revascularisation of chronic total occlusions and recurrence rate of ventricular arrhythmias

BACKGROUND

The impact of revascularisation of chronic total occlusions (CTO) on the incidence of ventricular arrhythmias (VA) remains to be elucidated.

METHODS

Based on prospectively gathered data, the recurrence rate of VAs following CTO treatment was retrospectively investigated. Patients presenting with VAs as clinical indication for CTO revascularisation were retrospectively selected out of three Belgian CTO registries (i.e. Ziekenhuis Oost-Limburg, UZ Leuven and CHR de la Citadelle). Freedom of VAs was defined as absence of non-sustained or sustained tachycardias (VT), ventricular fibrillations (Vfib) and ventricular extrasystoles (VES; <2500 VES/24 h). Long-term outcome in terms of reoccurrence of VAs was evaluated by reviewing patient records.

RESULTS

Between 2011 and 2019, 912 patients underwent a CTO-PCI across three Belgian centres. In total 43 patients (5%) presented with VAs as clinical indication for CTO revascularisation. Overall follow-up was 723 (391 - 1144) days. Fourteen (33%), 18 (42%), 5 (11%) and 6 (14%) presented with >2500 VES/24 hrs, non-sustained VT, sustained VT and Vfib, respectively. In those patients with a one-year follow-up available (n = 34), overall recurrence rate of VAs was 38% (within VA group: VES: 25%, non-sustained VT: 46%; sustained VT: 25% and Vfib: 60%).

CONCLUSION

Based on this retrospective data analysis, CTO revascularisation, in patients presenting with VAs as the main clinical indication, seems to beneficially impact the incidence of VAs, which ultimately might result in improved patients' outcome.

Ventricular fibrillation storm after revascularization of chronic total occlusion of the left anterior descending artery: is this reperfusion arrhythmia?

Electrical storm is a life-threatening emergency condition defined as three or more episodes of ventricular tachycardia or ventricular fibrillation (VF) within 24 hours requiring anti-tachycardia therapy, electrical cardioversion, or defibrillation. However, studies of the incidence of electrical storm after chronic total occlusion-percutaneous coronary intervention (CTO-PCI) are limited,⁷ and post-procedural VF after revascularization of CTO has not been described. The purpose of this article was to present a case of post-operative VF electrical storm after revascularization of CTO of the left anterior descending (LAD) artery to determine whether the electrical storm was caused by reperfusion arrhythmia or compromise of either branch vessels or the collateral circulation during intervention.

Incidence and characteristics of ventricular tachycardia in patients after percutaneous coronary revascularization of chronic total occlusions

Objectives

This study sought to investigate the prevalence of ventricular tachycardia after percutaneous coronary intervention (PCI) of chronic total occlusion (CTO).

Background

PCI of a CTO is associated with improvement of the left ventricular ejection fraction and possibly associated with reduced mortality. However, benefits of CTO-PCI must be weighed against a higher risk of procedure-related complications. The incidence of new-onset ventricular tachycardia after a successful CTO-PCI has not been investigated so far. In this retrospective registry we seek to describe characteristics and predictors of occurrence of post-procedural ventricular tachycardias.

Methods and results

Between 2010 and 2015, 485 patients underwent successful CTO-PCI at Heart Center Leipzig. Of them, 342 had complete follow-up and were further analyzed. Ventricular tachycardias were detected in 9 (2.6%) patients. All of them were monomorphic ventricular tachycardias occurring in median 1 day (interquartile range [IQR] 0.25–4.75 days) after PCI and caused prolongation of the hospital stay. Patients with ventricular tachycardia were older, had worse left ventricular ejection fraction (mean 33.1%, SD 5.9%) and more frequently a CTO of an infarct-related artery. The target vessel was not associated with the occurrence of ventricular arrhythmias. In multivariable analysis, only impaired left ventricular systolic function was an independent predictor for procedure-related ventricular tachycardia. Mortality rates were not different between patients with or without ventricular tachycardia.

Conclusion

Ventricular tachycardia can occur early after CTO-PCI as possible reperfusion arrhythmia and poorer left ventricular ejection fraction is the only independent predictor for onset. Although the occurrence of ventricular tachycardia after CTO-PCI seems not to influence mortality, awareness of this possible complication and longer monitoring may be recommended.

Exercise testing after chronic total coronary occlusion revascularization in patients with STEMI and a concurrent CTO: A subanalysis of the EXPLORE-trial

OBJECTIVES

To assess the effect of chronic total occlusion percutaneous coronary intervention (CTO PCI) on ventricular ectopy (VE) and symptomatology during exercise testing.

BACKGROUND

During exercise, the hypoxic myocardium in the CTO-territory can act as a substrate for VE and could lead to anginal complaints.

METHODS

In the EXPLORE-trial, 302 ST-segment elevation myocardial infarction (STEMI)-patients were randomized to CTO PCI or no-CTO PCI. For this sub-study, we analyzed all available exercise electrocardiograms (X-ECGs) at 4 months follow-up on symptoms and electrocardiographic parameters.

RESULTS

A total of 155 X-ECGs were available, 80 in the CTO PCI group (51.6%) and 75 in the no-CTO PCI group (48.4%). There were no differences regarding exercised time, achieved endurance, ST-deviation nor maximum heart-rate. The percentage of patients experiencing chest-pain during exercise was lower in the CTO PCI group (0% vs. 8.5%, p = .03). Also, there was a trend towards a higher maximum systolic blood pressure (SBP, 185 mmHg vs. 175, p = .09). No difference in VE was found between randomization groups, but patients with successful CTO PCI had a higher frequency of VE, compared to failed and no-CTO PCI (26% vs. 8%, p = .02). This did not result in higher frequencies of sustained ventricular arrhythmias or mortality.

CONCLUSION

In conclusion, in STEMI-patients, CTO PCI is associated with a small reduction of chest-pain during exercise and tended to be associated with an increase of maximum SBP. The observation that successful CTO PCI was associated with more VE during exercise, compared with failed/no-CTO PCI needs further exploration.