The impact of active cytomegalovirus infection on donor-derived cell-free DNA testing in heart transplant recipients.

BACKGROUND: Little is known about the relationship between cytomegalovirus (CMV) infections and donor-derived cell-free DNA (dd-cfDNA) in heart transplant recipients. METHODS: In our study, CMV and dd-cfDNA results were prospectively collected on single-organ heart transplant recipients. If the CMV study was positive, a CMV study with dd-cfDNA was repeated 1-3 months later. The primary aim was to compare dd-cfDNA between patients with positive and negative CMV results. RESULTS: Of 44 patients enrolled between August 2022 and April 2023, 12 tested positive for CMV infections, 25 were included as controls, and seven patients with a viral infection without CMV were excluded. Baseline characteristics did not differ significantly between CMV-positive and CMV-negative patients with the exception of a later median time post-transplant in the CMV-positive group (253 days vs. 120 days, p = .03). Dd-cfDNA levels were significantly higher in patients with CMV infections compared to those without (p < .001) with more patients in the CMV positive group showing dd-cfDNA results ≥.12% (75% vs. 8%, p < .001) and ≥.20% (58% vs. 8%, p = .002). Each 1 log10 copy/ml reduction in CMV viral load from visit 1 to visit 2 was associated with a.23% reduction in log10 dd-cfDNA (p = .002). CONCLUSION: Our findings suggest that active CMV infections may raise dd-cfDNA levels in patients following heart transplantation. Larger studies are needed to validate these preliminary findings.

The Utility of Home Sleep Apnea Testing in the Advanced Heart Failure Populations.

Untreated sleep disorders form a risk of coronary artery disease, hypertension, obesity, and diabetes mellitus. Access to polysomnography is limited, especially during the COVID-19 pandemic, with home sleep apnea testing (HSAT) being a potentially viable alternative. We describe an HSAT protocol in patients with advanced heart failure (HF). In a single-center, observational analysis between 2019 and 2021 in patients with advanced HF and heart transplant (HT), 135 screened positive on the STOP-Bang sleep survey and underwent a validated HSAT (WatchPAT, ZOLL-Itamar). HSAT was successful in 123 patients (97.6%), of whom 112 (91.1%; 84 HF and 28 HT) tested positive for sleep apnea. A total of 91% of sleep apnea cases were obstructive, and 63% were moderate to severe. Multivariable linear regression showed that the apnea hypopnea index was 34% lower in the HT group than in the HF group (p = 0.046) after adjusting for gender, and that this effect persisted in White patients but not among African-Americans. Patient characteristics were similar between groups, with coronary artery disease, diabetes mellitus, and hypertension as the most prevalent co-morbidities. In conclusion, sleep apnea remains prevalent in patients with HF with a high co-morbidity burden. HSAT is a feasible and effective tool for screening and diagnosis in this population.