Riva, Marta

Background Mitral valve prolapse (MVP) can be associated with ventricular arrhythmias (VA), but little is known about the relationship between VA and exercise in these patients. The aim of this study was to assess the occurrence and severity of VA during exercise tests in patients with MVP, and to explore the association between VA during exercise and the occurrence of arrhythmic events during follow-up. Methods In this multicentre study, 375 patients with MVP (58 (48–69) years, 53% male) who underwent a clinically indicated exercise test were included. Severity of VA during exercise was defined as: (1) no VA, (2) minor VA (premature ventricular contractions ≥5% or non-sustained ventricular tachycardia (nsVT) <120 beats per minute) and (3) major VA (nsVTs ≥120 beats per minute). Results During exercise test, 242 (65%) patients showed no VA, 88 (24%) minor VA and 45 (12%) major VA. Patients with minor and major VAs showed more often bileaflet prolapse and mitral annular disjunction (MAD) than patients with no VA (p<0.001). Over a median follow-up of 101 months (IQR 58–138 months), 35 patients (9%) developed a severe arrhythmic event, defined as sustained VA or ventricular fibrillation, implantation of an implantable cardioverter-defibrillator and VA ablation. At the Kaplan-Meier curve analysis, patients with major VA showed the worst arrhythmic event-free survival (log-rank p<0.001). On multivariable analysis, left ventricular end-systolic diameter, MAD and VA severity during exercise were independently associated with this outcome. Conclusions In patients with MVP, the occurrence of VA during exercise is associated with more advanced mitral valve abnormalities, including MAD, and with higher rates of severe arrhythmic events during follow-up. Performing an exercise test, combined with the clinical and echocardiographic assessments, may therefore offer important complementary information useful for patient management.

Abstract Aims Catheter ablation is an effective treatment for post-infarction ventricular tachycardia (VT). However, some patients may experience a worsened arrhythmia phenotype after ablation. We aimed to determine the prevalence and prognostic impact of arrhythmia exacerbation (AE) after post-infarction VT ablation. Methods and results A total of 1187 consecutive patients (93% men, median age 68 years, median ejection fraction 30%) who underwent post-infarction VT ablation at six centres were included. Arrhythmia exacerbation was defined as post-ablation VT storm or incessant VT in patients without prior similar events. During follow-up (median 717 days), 426 (36%) patients experienced VT recurrence. Events qualifying as AE occurred in 67 patients (6%). Median times to VT recurrence with and without AE were 238 [interquartile range (IQR) 35–640] days and 135 (IQR 22–521) days, respectively (P = 0.25). Almost half of the patients (46%) who experienced AE experienced it within 6 months of the index procedure. Patients with AE had had longer ablation times during the ablation procedures compared to the rest of the patients (median 42 vs. 34 min, P = 0.02). Among patients with VT recurrence, the risk of death or heart transplantation was significantly higher in patients with than without AE (hazard ratio 1.99, 95% CI 1.28–3.10; P = 0.002) after adjusting for age, gender, ejection fraction, cardiac resynchronization therapy, post-ablation non-inducibility, and post-ablation amiodarone use. Conclusion Arrhythmia exacerbation after ablation of infarct-related VT is infrequent but is independently associated with an adverse long-term outcome among patients who experience a VT recurrence. The mechanisms and mitigation strategies of AE after catheter ablation require further investigation.