Ongoing myocardial inflammation in complex ventricular arrhythmias
P Bicprendi, M Tydecks, H Krafft, M Popa, D Dischl, N Erhard, F Bahlke, F Englert, M Alfayad, E Koops, S Lengauer, M Telishevska, G Hessling, I Deisenhofer, T ReiterAbstract
Background
Not all patients with inflammatory myopericardial syndrome (IMPS) present with typical infarct-like symptoms or newly developed heart failure, but rather primarily with arrhythmias driven by ongoing myocardial inflammation. In these patients, the established non-invasive pathway, including cardiac magnetic resonance imaging, may fail to detect the underlying pathology and instead lead to a symptom-oriented treatment approach, including ventricular catheter ablation. Intraprocedurally obtained endomyocardial biopsies (EMB) may identify occult myocardial inflammation in patients not clinically suspected of ongoing inflammatory disease.
Objective
To evaluate the prevalence of ongoing inflammatory disease in patients with complex ventricular arrhythmias but no additional clinical findings and their long-term outcome.
Methods
This retrospective study included 70 patients with complex arrhythmias who underwent radiofrequency (RF) ablation and intraprocedural right ventricular EMB at a large tertiary electrophysiologial center between 2014–2023. Collected data included clinical and intraprocedural characteristics, ECG and imaging findings, EMB histopathology and follow-up data for up to 55 months.
Results
Among the analyzed patients, 51/70 (73%) met the inclusion criteria, 19 patients treated for supraventricular arrhythmias were excluded. No intraprocedural complications occurred. EMB revealed IMPS in 40/51 (78.4%) patients with elevated lymphocytes (10.5 [3–19]) in 31/40 (77.5%) and elevated macrophages in 35/40 (87.5%) cases. The remaining patients were diagnosed with tachymyopathy, ischemic heart disease or amyloidosis. Ablation strategy in patients with ongoing myocardial inflammation required complex approaches in 30/40 (75%), including additional epicardial ablation in 11/40 (27.5%), while a single-focus RF ablation sufficed in 10/40 (25%). EMB showed chronic or healing inflammation in 9/18 (50%) of these patients, chronic active myocarditis in 1/18 (5.6%) and acute myocarditis in 2/18 (11.1%). Based on EMB and at the treating physician’s discretion, 9/40 (22.5%) patients received immunsuppresive therapy and 31/40 (77.5%) ablation only. During follow-up, no patient recieving immunesuppressive therapy experienced recurrent ventricular arrhythmias. Among the other patients, 18/31 (58.1%) required additional RF ablation after a median interval of 5 [1-16] months, 4/31 (12.9%) remained on antiarrhythmic mediation and the repeat procedures identified ≥2 foci in 12/18 (66.7%).
Conclusion
Our data demonstrate a high prevalence of ongoing myocardial inflammation in patients with ventricular tachycardia despite the absence of other clinical signs and its impact on complex ablation strategies. Our data also suggest an influence of untreated myocardial inflammation on the recurrence rate of arrhythmias after initial ablation. These findings could guide a tailored treatment strategy, including anti-inflammatory therapy, to improve arrhythmia control.