Prosthetic Valve Endocarditis—Insights from the NatIonal Danish Endocarditis stUdieS (NIDUS) Registry

Background: Prosthetic valve endocarditis (PVE) is considered a serious complication of valve replacement, and worse outcomes have been reported for PVE versus native valve endocarditis (NVE). Comprehensive data on clinical presentation and practice patterns are lacking. Methods: The Danish NatIonal enDocarditis stUdieS (NIDUS) registry was used to obtain data on all patients with left-sided PVE or NVE from 2016–2021 in Denmark. Patients were classified as having a PVE or NVE according to the modified Duke criteria One-year mortality rates for PVE and NVE were assessed using the reversed Kaplan–Maier estimator and adjusted Cox’s regression models. Results: In total, 3017 patients were included, of which 791 (26.2%) had PVE and 2226 (73.8%) had NVE. In the PVE group, the median age was 76 years [IQR 70–82], and 74% were males. In the NVE group, the median age was 73 years [IQR 63–80], and 65% were males. The comorbidity burden was similar between groups. The median length of hospital stay was 44 days [IQR 28–52] for PVE and 34 days [IQR 24–45] for NVE. In the PVE group, 567 (74.8%) had definite IE vs. 1863 (82.5%) in the NVE group. At admission, the proportion of patients who presented with embolism (PVE 10.1% vs. NVE 12.5%) and sepsis (PVE 24.4% vs. NVE 23.2%) were comparable. The most common microbiological etiologies for PVE vs. NVE were Streptococcus spp. (30.2% vs. 33.8%), S. aureus (21.6% vs. 33.4%), and Enterococcus spp. (24.5% vs. 14.3%). Surgery during admission was performed in 23.4% of patients with PVE vs. 20.7% with NVE. The absolute risk of one-year mortality in patients with PVE was 30% [95% CI: 27–33], and for NVE, it was 35% [95% CI 33–37] (p = 0.0036), with an adjusted hazard ratio (HR) of 0.79 [95% CI 0.68–0.92], with p = 0.002. This difference between groups was mainly driven by those above the age of 70 years. Conclusions: This nationwide study showed that patients with PVE were older, had similar comorbidity burden, and had a longer length of hospital stay compared to patients with NVE. The PVE group had a numerically higher prevalence of Enterococcus spp. Although PVE is a severe condition, our findings indicate that the associated outcomes are more comparable to or even better than NVE than previously assumed, probably related to the unselected and nationwide nature of these data.