Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) study: the predictive role of programmed ventricular stimulation

Abstract

Aims Myotonic dystrophy type 1 (DM1) predisposes to the development of life-threatening arrhythmias and sudden cardiac death. Our study aimed to evaluate the prognostic value of programmed ventricular stimulation (PVS) in DM1 patients with conduction system disease. Methods and results Arrhythmic CArdiac DEath in MYotonic dystrophy type 1 patients (ACADEMY 1) is a double-arm non-randomized interventional prospective study. Myotonic dystrophy type 1 patients with permanent cardiac pacing indication were eligible for the inclusion. The study population underwent to pacemaker (PM) or implantable cardioverter-defibrillator (ICD) implantation according to the inducibility of ventricular tachyarrhythmias at PVS. Primary endpoint of the study was a composite of appropriate ICD therapy and cardiac arrhythmic death. The secondary study endpoint was all-cause mortality. Seventy-two adult-onset DM1 patients (51 ± 12 years; 39 male) were enrolled in the study. A ventricular tachyarrhythmia was induced in 25 patients (34.7%) at PVS (PVS+) who underwent dual chambers ICD implantation. The remaining 47 patients (65.3%) without inducible ventricular tachyarrhythmia (PVS−) were treated with dual-chamber PM. During an average observation period of 44.7 ± 10.2 months, nine patients (12.5%) met the primary endpoint, four in the ICD group (16%) and five (10.6%) in the PM group. Thirteen patients died (18.5%), 2 in the ICD group (8%) and 11 in PM group (23.4%). The Kaplan–Meier analysis did not show a significantly different risk of both primary and secondary endpoint event rates between the two groups. Conclusions The inducibility of ventricular tachyarrhythmias has shown a limited value in the arrhythmic risk stratification among DM1 patients.

The pivotal role of ECG in cardiomyopathies

“…As minor criteria, we find the presence of inverted T waves in leads V1 and V2 in individuals with completed pubertal development (in the absence of complete RBBB) and inverted T waves in V1–V4 in individuals with completed pubertal development in the presence of complete RBBB. Over the years, a correlation has been demonstrated between T-wave inversion and right ventricular dysfunction and dilatation evaluated on both echocardiogram and magnetic resonance imaging ( 54 ) ( Figure 4B,C ). Some studies have hypothesized the importance of the amplitude of inverted T waves in right precordial leads, particularly the prevalence of T waves of >2 mm in V1, found in approximately 90% of patients diagnosed with ARVC, as a diagnostic marker of the pathology itself.…”

“…Pathophysiological mechanisms favoring VT include reentry circuits promoted by fibrotic foci, fatty infiltration, and delayed conduction in the His–Purkinje system. The occurrence of sustained and non-sustained VT may be predictive of subsequent malignant tachyarrhythmias in subjects with MD1, in contrast to the inducibility of VT during an EPS study, which has a limited value in the risk stratification of these subjects ( 54 ).…”

“…The ECG remains one of the first and most effective instrumental approaches for the diagnostic suspicion of arrhythmogenic cardiomyopathy. As the definition has evolved and the field has been enriched with new nosological entities, the electrocardiographic criteria have also undergone a concomitant evolution with the possibility of distinguishing electrocardiographic features peculiar to arrhythmogenic cardiomyopathy of the right ventricle and the left ventricle, and when these same electrocardiographic features are associated, they may be the expression of a biventricular form ( 54 ).…”

“…Various criteria, including electrocardiographic criteria, have been drawn up over the years to highlight this nosological development. In particular, with the new “Padua Criteria,” some of the electrocardiographic findings have been reclassified into the different forms of arrhythmogenic cardiomyopathy ( 54 , 55 ). Independent of each electrocardiographic finding and its sensitivity and specificity value in the diagnosis of the different forms of ACM, the presence of these ECG findings may be the expression of an underlying substrate in which the ventricular wall is composed of vital myocardium and regions of fibro-fatty replacement of the myocardium itself ( 60 ).…”

Comprehensive Cardiovascular Management of Myotonic Dystrophy Type 1 Patients: A Report from the Italian Neuro-Cardiology Network

“…To date, little is known about the timing and the role of programmed ventricular stimulation for arrhythmic risk stratification [30,74]. The ACADEMY 1, a prospective single-center study about the electrophysiological study-guided ICD strategy in the prevention of arrhythmic cardiac death in MD1 patients, suggests the inducibility of VT has a limited value in the arrhythmic risk stratification among MD1 patients [75,76].…”