Log in to MyACC
CMR and Risk of Ventricular Arrhythmias
Quick Takes
- Structural abnormalities seen on CMR are very common among patients with a history of ventricular tachycardia (VT) or aborted sudden cardiac death.
- CMR results in change in diagnosis of approximately 1:4 patients with nonsustained VT and 2:5 patients with sustained VT or aborted sudden cardiac death.
- Among patients with a history of VT or aborted sudden cardiac death, abnormal cardiac MRI was associated with increased risk of major adverse cardiac events.
Study Questions:
Among patients with a history of ventricular arrhythmias, how does cardiac magnetic resonance imaging (CMR) affect diagnosis, management, and prognosis?
Methods:
The authors conducted a single-center retrospective review of patients referred for clinically indicated CMR for assessment of ventricular arrhythmias including nonsustained ventricular tachycardia (NSVT) (≥3 beats and <30 seconds, without hemodynamic compromise), sustained ventricular tachycardia (VT), or aborted sudden cardiac death (SCD). Pre- and post-CMR diagnoses were determined in blinded fashion across 10 etiologic categories. Clinical endpoints were adjudicated from clinical records with a primary composite endpoint of major adverse cardiac events (MACE): 1) death from any cause, 2) recurrent ventricular arrhythmias (VT/ventricular fibrillation) requiring treatment, and 3) hospitalization for congestive heart failure.
Results:
A total of 642 patients were included, 345 with a history of NSVT and 297 with a history of VT or SCD. CMR identified structural heart disease in 333 patients (52%), an increase from 167 who had evidence of structural heart disease before CMR. Common new diagnoses included myocarditis and ischemic heart disease. Over a median follow-up of 4.4 years, MACE occurred in 51 patients referred for NSVT and 104 patients referred for VT or SCD. After multivariable adjustment, abnormal CMR was associated with a 5.2-fold increased hazard of MACE among patients with NSVT and 1.88-fold increased hazard for MACE among those with VT or SCD. Rates of MACE were low for those with a structurally normal heart and NSVT (0.7%/year), but for those with a history of VT or SCD, even with a normal CMR, MACE occurred at 3.8%/year. Nonetheless, these rates were substantially higher with an abnormal CMR.
Conclusions:
The authors conclude that CMR contributes to diagnostic and prognostic assessment in patients with NSVT, VT, or SCD.
Perspective:
This study adds to a large body of literature reporting the value of CMR, especially assessment of late gadolinium enhancement, to diagnosis and prognosis in patients with cardiomyopathy and/or arrhythmia. The value of this study is a focus on patients with arrhythmia and a large sample size. In addition, it was performed at a center of excellence for CMR. These data suggest that important new diagnoses may be uncovered with CMR, which may lead to changes in treatment. Although the prognostic value is strong, it is less clear whether the prognosis of a relatively normal CMR study in patients with VT or SCD is sufficiently benign as to be able to safely defer placement of an implantable cardioverter-defibrillator.
Clinical Topics: Arrhythmias and Clinical EP, Cardiovascular Care Team, Heart Failure and Cardiomyopathies, Noninvasive Imaging, Prevention, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Acute Heart Failure, Magnetic Resonance Imaging
Keywords: Arrhythmias, Cardiac, Death, Sudden, Cardiac, Diagnostic Imaging, Gadolinium, Heart Failure, Magnetic Resonance Imaging, Myocarditis, Myocardial Ischemia, Risk, Secondary Prevention, Tachycardia, Ventricular, Treatment Outcome
< Back to Listings
