Hong, KyungPyo

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.

AbstractPurposeOverall there is a lack of evidence on the accuracy and precision of phase‐contrast (PC) MRI in patients with cardiac implantable electronic devices (CIEDs). The purpose of this study is to determine whether aortic velocity measurements are influenced by a CIED.MethodsWe scanned 21 adult patients and 8 pediatric volunteers using clinical standard PC and real‐time PC (rt‐PC) sequences with and without a CIED generator taped on human subjects (below the left clavicle for adults and children; also on the abdomen for children) to mimic image artifacts. Peak and mean velocities above the aortic valve were calculated.ResultsThe Bland–Altman analyses on peak velocity measurements in pediatric subjects showed that both the accuracy and precision worsen as the distance between the CIED and aortic valve decreases (i.e., from abdomen to below the left clavicle). Specifically, both the bias and the coefficient of variation (CV) for both clinical PC and rt‐PC increased from the abdominal position (clinical: bias = −1.1%, CV = 4.3%; rt‐PC: bias = −0.3%, CV = 3.4%) to the clavicle position (clinical: bias = −4.0%, CV = 8.1%; rt‐PC: bias = 8.2%, CV = 7.3%). A similar trend was observed for mean velocity. The mean difference in peak and mean velocity measurements between rt‐PC with CIED (either position) and clinical standard PC with no CIED was within 7.5%. In adult patients, the mean difference between rt‐PC with CIED and clinical standard PC with CIED in peak velocity was 6.9%, and the CV was 7.9%.ConclusionThis study demonstrates that aortic velocity measurements are influenced by CIED in both adult and pediatric subjects.