Cardiac MRI improves diagnosis accuracy in ventricular arrhythmias
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Multiparametric cardiac MRI in patients presenting with nonsustained ventricular tachycardia and ventricular tachycardia/sudden cardiac death led to a change in diagnosis in approximately one-third of patients, according to data presented at the virtual American College of Cardiology Scientific Session.
Cardiac MRI was an independent predictor of adverse endpoints, according to the presentation.
Referral for cardiac MRI
Yin Ge, MD, cardiovascular imaging fellow at Brigham and Women’s Hospital, and colleagues analyzed data from 642 patients (mean age, 54 years; 40% women) who were referred for cardiac MRI for ventricular arrhythmias. Patients were categorized as nonsustained ventricular tachycardia (n = 345; mean age, 55 years; 46% women) or sustained ventricular tachycardia or aborted sudden cardiac death (n = 297; mean age, 53 years; 33% women).
“We evaluated cardiac MRI parameters as follows: left- and right-sided ejection fraction, the presence of regional wall motion abnormality, LV mass index to body surface area and the presence of [late gadolinium enhancement] indicative of scar,” Ge said during the presentation.
A structurally abnormal cardiac MRI was defined as an LVEF less than 50%, late gadolinium enhancement, wall motion abnormalities in the left or right ventricle and abnormal LV thickness meeting criteria for hypertrophic cardiomyopathy.
The primary endpoint was CV death or recurrent sustained ventricular tachycardia/ventricular fibrillation. The secondary endpoint was defined as recurrent sustained ventricular tachycardia/ventricular fibrillation, death or HF hospitalization.
Cardiac MRI detected a structurally abnormal heart in 52% of patients. This imaging modality resulted in a change in diagnostic impression in 27% of patients in the nonsustained ventricular tachycardia group vs. 41% of those in the sustained ventricular tachycardia or aborted sudden cardiac death group (P < .001). The most common new diagnoses were myocarditis, ischemic heart disease and nonischemic cardiomyopathy.
The primary endpoint occurred in 117 patients during a median follow-up of 4.4 years. The secondary endpoint was observed in 155 patients.
Patients with nonsustained ventricular tachycardia and a normal cardiac MRI had a lower annual event rate vs. those with sustained ventricular tachycardia or aborted sudden cardiac death and an abnormal cardiac MRI (0.2% vs. 10.6%).
An independent predictor of major adverse CV events was the presence of structural abnormalities on cardiac MRI (HR = 3.65; 95% CI, 2.09-6.27).
Take-aways from study findings
“The results are probably selected toward higher-risk cohorts, but what was important is that even in this higher-risk cohort, those with nonsustained ventricular tachycardia and normal cardiac MRI was still extremely helpful,” Ge said during the discussion. “This message is actually quite interesting because it generalizes to other populations.”
During the discussion, Christopher R. deFilippi, MD, member of the Inova Heart and Vascular Institute in Falls Church, Virginia, said the study is important. “I’m someone who sees these patients in our cardiac ICU frequently and was never quite sure how to address some of the findings other than [late gadolinium enhancement] on the cardiac MRI. This was very insightful and I’m sure for my EP colleagues as well,” he said. – by Darlene Dobkowski
Reference:
Ge Y, et al. Young Investigator Awards: Clinical Investigations. Presented at: American College of Cardiology Scientific Session; March 28-30, 2020 (virtual meeting).
Disclosures: Ge reports no relevant financial disclosures. Cardiology Today could not confirm relevant financial disclosures for deFilippi at the time of publication.