Individual-Level Socioeconomic Position and Long-Term Prognosis in Danish Heart-Transplant Recipients

Socioeconomic deprivation can limit access to healthcare. Important gaps persist in the understanding of how individual indicators of socioeconomic disadvantage may affect clinical outcomes after heart transplantation. We sought to examine the impact of individual-level socioeconomic position (SEP) on prognosis of heart-transplant recipients. A population-based study including all Danish first-time heart-transplant recipients (n = 649) was conducted. Data were linked across complete national health registers. Associations were evaluated between SEP and all-cause mortality and first-time major adverse cardiovascular event (MACE) during follow-up periods. The half-time survival was 15.6 years (20-year period). In total, 330 (51%) of recipients experienced a first-time cardiovascular event and the most frequent was graft failure (42%). Both acute myocardial infarction and cardiac arrest occurred in ≤5 of recipients. Low educational level was associated with increased all-cause mortality 10-20 years post-transplant (adjusted hazard ratio [HR] 1.95, 95% confidence interval [CI] 1.19-3.19). During 1-10 years post-transplant, low educational level (adjusted HR 1.66, 95% CI 1.14-2.43) and low income (adjusted HR 1.81, 95% CI 1.02-3.22) were associated with a first-time MACE. In a country with free access to multidisciplinary team management, low levels of education and income were associated with a poorer prognosis after heart transplantation.

Magnetic resonance imaging in patients with temporary external pacemakers

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): This work was supported by Aarhus University, the Danish Heart Foundation (grant number R140-A9482-B2407); Health Research Foundation of Central Denmark Region (grant number R64-A3194-B1667); and Gangstedfonden.

Background

Magnetic resonance imaging (MRI) is increasingly becoming the imaging modality of choice for many clinical disorders. According to guidelines, MRI can safely be performed 6 weeks after implantation of a MRI-conditional permanent pacemaker. However, there is no recommendations and only very limited evidence regarding MRI in patients treated with temporary external pacemakers. Such patients thus may be denied the opportunity for well-indicated MRI.

Purpose

To describe safety and feasibility of MRI in patients with temporary external pacemakers.

Method

We reviewed patient records of all patients treated with temporary external pacing between 2016 and 2020 at a tertiary centre. Temporary pacing was established using a transvenous standard active fixation pacing lead inserted percutaneously and connected to a MRI-conditional pacemaker taped to the skin. Information on baseline characteristics, indication, days of hospital and pacemaker function before and after MRI was gathered. Before MRI, devices were programmed according to guidelines for permanent pacemakers and the device was fixated to avoid movement due to the magnetic field of the MRI system. Patients were monitored during MRI. Values are reported as N (%), and continuous variables are presented as median (interquartile range [IQR]) or mean ± SD.

Results

A total of 827 patients received a temporary pacemaker. MRI was performed in 44 (5%) patients. Mean age was 71 ­± 13 years and 13 (30%) were females. Indication for temporary device were atrioventricular block (20 [45%]), aborted cardiac arrest (9 [21%]), infective endocarditis (9 [21%]), and other (6 [14%]). MRI was performed to rule out or confirm structural heart disease (16 [36%]), cerebral disease (9 [20%]), spondylodiscitis (7 [16%]), or other (12 [27%]), which was not able to do with other imaging modalities. Cardiac MRI was performed in 22 (50%) patients, while MRI of cerebrum, spine, abdomen, and lower extremities were performed in the remaining patients. Median (IQR) time from implantation of the temporary device to MRI was 6 (3–11) days. During MRI, we observed no device-related malfunction or arrhythmia. Nor did we detect any change in lead sensing, impedance, or pacing threshold. A final diagnosis was confirmed in 27 (61%) patients after MRI. However, MRI provided information to guide the clinical management in all cases without artifacts compromising the diagnostic image quality. Instead of a dual chamber pacemaker, 7 (22%) patients had implanted a cardiac resynchronization therapy and/or implantable cardioverter defibrillator due to the MRI diagnosis. A permanent pacemaker was implanted in 32 (73%) patients within median (IQR) 12 (7–23) days after temporary pacing was established.

Conclusion

MRI is feasible and safe in patients with temporary external pacing established with a regular MRI-conditional device and a standard active fixation lead. The MRI was helpful in determining type of permanent device.

The DR6 protein from human herpesvirus-6B induces p53-independent cell cycle arrest in G2/M

HHV-6B infection inhibits cell proliferation in G2/M, but no protein has so far been recognized to exert this function. Here we identify the protein product of direct repeat 6, DR6, as an inhibitor of G2/M cell-cycle progression. Transfection of DR6 reduced the total number of cells compared with mock-transfected cells. Lentiviral transduction of DR6 inhibited host cell DNA synthesis in a p53-independent manner, and this inhibition was DR6 dose-dependent. A deletion of 66 amino acids from the N-terminal part of DR6 prevented efficient nuclear translocation and the ability to inhibit DNA synthesis. DR6-induced accumulation of cells in G2/M was accompanied by an enhanced expression of cyclin B1 that accumulated predominantly in the cytoplasm. Pull-down of cyclin B1 brought down pCdk1 with the inactivating phosphorylation at Tyr15. Together, DR6 delays cell cycle with an accumulation of cells in G2/M and thus might be involved in HHV-6B-induced cell-cycle arrest.