Ring-like nonischemic left ventricular (LV) scarring in patients with idiopathic nonsustained ventricular arrhythmias (VA) may be associated with malignant arrhythmic events, according to a study published in Circulation.
This retrospective, multicenter study, data from 686 patients with idiopathic nonsustained VA collected between 2002 and 2018 were analyzed. Patients underwent physical examination, 12-lead electrocardiograph, transthoracic echocardiograph, ischemic evaluation, and contrast-enhanced cardiac magnetic resonance imaging. The study’s outcome was a composite of all-cause death, cardiac arrest (resuscitated and due to ventricular fibrillation), adequate use of implantable cardioverter defibrillator (ICD), and unstable ventricular tachycardia.
Evidence of late gadolinium enhancement (LGE) was observed in 15% of patients, and 4% and 11% had a ring- and non ring-like pattern of scar, respectively. Patients with a ring-like scar LGE vs non ring-like scar or no LGE were found to be more frequently: men, with a history of unexplained syncope, and a family history of sudden cardiac death or cardiomyopathy, and to be younger (P <.01 for all).
Patients with a ring-like scar vs non ring-like scar or no LGE had more frequent right bundle branch block morphology (100% vs 42% vs 8%, respectively; P <.01) and premature ventricular contractions (46% vs 26% vs 4%, respectively; P <.01), larger LV volume (median, 90 vs 77 vs 77 ml/m2, respectively; P <.01), and lower LV ejection fraction (median, 57% vs 65% vs 64%, respectively; P <.01).
The extent of LGE was greater in patients with a ring- vs non ring-like pattern of scar (median: 4% of LV vs 3% of LV, respectively; P <.01), and its distribution had a predominantly lateral (89% vs 54%, respectively; P <.01) and inferior (82% vs 26%, respectively; P <.01) wall involvement in those with ring-like vs non-ring-like scarring.
Resuscitated cardiac arrests were more frequent in patients with ring-like scarring (21%), compared with those with non ring-like scarring (14%), or no LGE (0.3%; P <.01). Appropriate ICD shocks were more frequent in participants with ring- vs non ring-like pattern or no LGE (18% vs 5% and 0%; P <.01), and 11% of patients with a ring-like pattern died vs none in the other 2 groups (P <.01).
Increased risk for the composite outcome was found to be independently associated with ring-like scar pattern LGE (hazard ratio [HR], 68.98; 95% CI, 14.67-324.39; P <.01).
This study may have included some selection bias as criteria for referring patients to undergo cardiac magnetic resonance imaging were not prespecified, and relied on physician opinion.
“Identification of this specific LGE pattern deserves proper clinical attention, close follow-up and careful evaluation for primary prevention ICD implantation,” concluded the study authors.
Muser D, Nucifora G, Pieroni M, et al. Prognostic Value of Non-Ischemic Ring-Like Left Ventricular Scar in Patients with Apparently Idiopathic Non-Sustained Ventricular Arrhythmias. [published online January 6, 2021] Circulation doi:10.1161/CIRCULATIONAHA.120.047640