Introduction:
Sudden death due to ventricular arrhythmias (VA) is one of the main causes of mortality in patients with heart failure and preserved ejection fraction (HFpEF). Ventricular fibrosis in HFpEF has been suspected as a substrate of VA, but the degree of fibrosis has not been well characterized.
Hypothesis:
HFpEF patients with increased degree of fibrosis will manifest more VA.
Methods:
Cedars-Sinai medical records were probed using Deep 6 artificial intelligence data extraction software to identify patients with HFpEF who underwent cardiac magnetic resonance imaging (MRI). MRI of identified patients were reviewed to measure extra-cellular volume (ECV) and degree of fibrosis. Ambulatory ECG monitoring (Ziopatch) of those patients were also reviewed to study the prevalence of arrhythmias.
Results:
A total of 12 HFpEF patients who underwent cardiac MRI were identified. Patients were elderly (mean age 70.3 ± 7.1), predominantly female (83%), and overweight (mean BMI 32 ± 9). Comorbidities included hypertension (83%), dyslipidemia (75%), and coronary artery disease (67%). Mean left ventricular ejection fraction by echocardiogram was 63 ± 8.7%. QTc as measured on ECG was not significantly prolonged (432 ± 15 ms). ECV was normal in those patients for whom it was available (24.2 ± 3.1, n = 9) with 3/12 patients (25%) demonstrating ventricular fibrosis by MRI (average burden of 9.6 ± 5.9%). Ziopatch was obtained in 8/12 patients (including all 3 patients with fibrosis) and non-sustained ventricular tachycardia (NSVT) was identified in 5/8 (62.5%). One patient with NSVT and without fibrosis on MRI also had a sustained VA recorded. In those patients who had Ziopatch monitoring, there was no association between presence of fibrosis and NSVT (X2 = 0.035, p = 0.85).
Conclusions:
Ventricular fibrosis was present in 25% of HFpEF patients in this study and NSVT was observed in 62.5% of those patients with HFpEF who had Ziopatch monitoring. The presence of fibrosis by Cardiac MRI was not associated with NSVT in this study; however, the size of the cohort precludes broadly generalizable conclusions about this association. Further investigation is required to better understand the relationship between ventricular fibrosis by MRI and VA in patients with HFpEF.
Cardiac MRI for the prognostication of heart failure with preserved ejection fraction: A systematic review and meta-analysis
