Fan, Lexiaozi

A 32-fold accelerated real-time cine MRI sequence (radial sampling) demonstrated better temporal resolution and image quality than a 16-fold sequence (Cartesian sampling) in patients with cardiac implantable electronic devices and arrhythmias.

Background: The prevalence of cardiac implantable electronic devices (CIED) is increasing, with over 300,000 new implants annually in the U.S. Stress cardiac magnetic resonance (CMR) has proven as a powerful modality for myocardial characterization, enabling accurate diagnosis of different cardiac conditions. In patients without devices, CMR findings have also demonstrated prognostic value for major adverse cardiovascular events (MACE) and guide clinical decision-making. However, its use in CIED patients has historically been limited due to safety and image quality concerns. Hypothesis: We aimed to evaluate the prognostic value of CMR imaging using wideband sequences in CIED patients. Methods: CIED patients referred for clinical CMR were included prospectively and retrospectively between January 2020 and February 2025. All patients underwent a stress CMR protocol, which included cine, wideband late gadolinium enhancement (LGE), wideband T1 mapping, and wideband stress/rest perfusion imaging. Clinical follow-up is ongoing. The primary endpoint was the occurrence of MACE, defined as the composite of myocardial infarction, heart failure hospitalization, implantable cardioverter defibrillator (ICD) therapy, cardiac death, revascularization, or heart transplant. Results: A total of 89 patients were included (median age 69.0 [58.0–75.5] years; 62.9% male). Device types included pacemakers (33.7%), ICDs (48.3%), and cardiac resynchronization therapy devices (16.9%). Over a median of follow-up of 613 days [355-991], 21 patients experienced a MACE. In unadjusted models, higher left ventricular ejection fraction (LVEF) (per 5%) was significantly associated with a lower risk of MACE (odds ratio [OR] 0.80, 95% confidence interval [CI] 0.65–0.95; p=0.016), as was higher stress myocardial blood flow (MBF) (per 0.25 mL/g/min increase: OR 0.78, 95% CI 0.60–0.98; p=0.05). In contrast, greater LV myocardial mass (per 10 g) was significantly associated with a higher risk of MACE (OR 1.27, 95% CI 1.08–1.52; p = 0.006), figure 1. Conclusion: The use of wideband sequences enabled the assessment of prognostic imaging value in CIED patients. LVEF remains a strong and consistent predictor of MACE in this population and LV mass was significantly associated with higher rates of MACE reflecting the influence of underlying cardiomyopathy. While stress perfusion CMR imaging showed promising trends, further studies with longer follow-up are needed to clarify its prognostic value in this population.

AbstractIntroductionA recent study reported that diffuse left ventricular (LV) fibrosis is a predictor of atrial fibrillation (AF) recurrence following catheter ablation, by measuring postcontrast cardiac T1 (an error prone metric as per the 2017 Society for Cardiovascular Magnetic Resonance consensus statement) using an inversion‐recovery pulse sequence (an error prone method in arrhythmia) in AF ablation candidates. The purpose of this study was to verify the prior study, by measuring extracellular volume (ECV) fraction (an accurate metric) using a saturation‐recovery pulse sequence (accurate method in arrhythmia).Methods and ResultsThis study examined 100 AF patients (mean age = 62 ± 11 years, 69 males and 31 females, 67 paroxysmal [pAF] and 33 persistent [peAF]) who underwent a preablation cardiovascular magnetic resonance (CMR) exam. LV ECV and left atrial (LA) and LV functional parameters were quantified using standard analysis methods. During an average follow‐up period of 457 ± 261 days with 4 ± 3 rhythm checks per patient, 72 patients maintained sinus rhythm. Between those who maintained sinus rhythm (n = 72) and those who reverted to AF (n = 28), the only clinical characteristic that was significantly different was age (60 ± 12 years vs 66 ± 9 years); for CMR metrics, neither mean LV ECV (25.1 ± 3.3% vs 24.7 ± 3.7%), native LV T1 (1093.8 ± 73.5 ms vs 1070.2 ± 115.9 ms), left ventricular ejection fraction (54.1 ± 11.2% vs 55.7 ± 7.1%), nor LA end diastolic volume/body surface area (42.4 ± 14.8 mL/m2 vs 43.4 ± 19.6 mL/m2) were significantly different (P ≥ .23). According to Cox regression tests, none of the clinical and imaging variables predict AF recurrence.ConclusionNeither LV ECV nor other CMR metrics predict recurrence of AF following catheter ablation.