Elsevier

Heart Rhythm

Volume 18, Issue 1, January 2021, Pages 20-26
Heart Rhythm

Clinical
Ablation
Clinical significance of myocardial scar in patients with frequent premature ventricular complexes undergoing catheter ablation

https://doi.org/10.1016/j.hrthm.2020.07.030Get rights and content

Background

Frequent premature ventricular complexes (PVCs) can result in PVC-induced cardiomyopathy (PICM). Scarring has been described in patients with frequent PVCs in the absence of apparent heart disease and in patients with known cardiomyopathy.

Objective

The purpose of this study was to determine the impact of focal myocardial scarring as detected by cardiac magnetic resonance imaging (CMR) on PICM, procedural outcomes, and recovery of left ventricular function in patients with frequent PVCs.

Methods

A total of 351 consecutive patients (181 men; age 53 ± 15 years; ejection fraction [EF] 51% ± 12%) with frequent PVCs referred for ablation were included. CMR was performed in all patients before the ablation procedure. A ≥10% increase in EF or normalization of a previously abnormal EF was defined as evidence of PICM.

Results

Myocardial scarring was present in 134 of 351 patients (38%); 66 of 134 patients (49%) with scarring and 54 of 217 patients (25%) without scarring had improvement or normalization of EF after ablation. The presence of myocardial scarring, PVC burden >22%, male sex, asymptomatic status, and PVC QRS width >150 ms were associated with PICM by univariate analysis (P <.01 for all). The presence of scar was independently associated with PICM (odds ratio 2.2; 95% confidence interval 1.3–3.7; P <.005). The success rate of PVC ablation was lower in patients with scarring than in patients without focal scarring (mean 70% vs 82%; P <.01).

Conclusion

Focal scar defined by CMR is independently associated with PICM. Although ablation outcomes are worse in the presence of scarring, EF recovery can occur in most of these patients after ablation.

Introduction

Frequent premature ventricular complexes (PVCs) can cause a reversible form of cardiomyopathy.1 PVC-induced cardiomyopathy (PICM) has been described in patients with and those without structural heart disease.2 In up to 25% of patients without apparent heart disease, scarring has been detected by cardiac magnetic resonance imaging (CMR).3 Whether the presence of scarring impacts on the development of PICM and whether scarring impacts on the procedural outcomes of PVC ablation and postablation recovery of left ventricular (LV) dysfunction are unclear. The purpose of this study was to assess the impact of focal scarring on PICM and the outcomes of catheter ablation of frequent PVCs.

Section snippets

Patient characteristics

The study consisted of 351 consecutive patients (170 women [48%]; age 53 ± 15 years; ejection fraction [EF] 51% ± 12%) with frequent PVCs who were referred for catheter ablation (Table 1). Patients had failed to respond to a mean of 1.24 ± 0.9 antiarrhythmic medications. All patients underwent CMR with late gadolinium enhancement for assessment of myocardial scarring. Seventy-seven patients had known heart disease before the appearance of frequent PVCs, including 38 with ischemic cardiomyopathy

CMR findings

A total of 134 of 351 patients (38%) had scarring on CMR. Patients with scarring more frequently had PICM (66/134 [49%]) compared to patients without scarring (54/217 [25%]; P <.001). Scar volume in patients with PICM was greater than in patients without PICM (total scar: 0.31 [0–1.33] cm3 vs 0 [0–0.46] cm3; P = .01).

In patients with scarring, there was no significant difference in scar size between patients without improvement of the EF postablation compared to scar size in patients in whom EF

Main findings

The presence of focal myocardial scarring is independently associated with PICM. Despite lower procedural success rates in patients with scar, significant improvement in EF could be seen after ablation in most of these patients.

Scar and cardiomyopathy

To the best of our knowledge, this study is the first to report on DE-CMR–defined focal cardiac scar as a factor associated with PICM. This finding has important clinical implications because advanced cardiac imaging is not routinely performed in patients with frequent

Conclusion

Most patients with frequent PVCs and PICM have focal scarring by CMR. The presence of focal myocardial scarring is independently associated with PICM. Although the presence of scar is associated with lower ablation success rates and lower postablation EF, successful ablation in these patients still can result in substantial recovery of EF. Longitudinal studies in patients with PVCs may help to further clarify temporal relationships and causality between scarring and PICM.

References (18)

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Funding sources: This research was supported by funding from the French National Research Agency (ANR) under Grant Agreements Equipex MUSIC ANR-11-EQPX-0030 and IHU LIRYC ANR-10-IAHU-04; and from the European Research Council under Grant Agreement ERC No. 715093.

Disclosures: The authors have no conflicts of interest to disclose.

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