Contemporary profile of infective endocarditis in young patients in the era of ageing population: a comparative study
Authors: Gomez-Ramirez D , Olmos C , Zulet P , Lopez J , Perez-Camargo D , Saez C , Jeronimo A , Pulido P , Perez-Serrano J , De Miguel-Alava M , Cabezon G , Carnero M , San-Roman J A , Vilacosta I 
Published: November 2023

Abstract

Aim
The aim of the study is to describe the main differences in epidemiological characteristics, clinical features and prognosis between IE patients aged &lt;50 and ≥50 years.

Methods
A total of 1935 episodes of IE were prospectively recruited at three tertiary centres from 1996 to 2022. Patients were classified into two groups: &lt;50 years (n=333, median age 40 [IQR 33-45] and ≥50 years (n=1602, median age 71 [IQR 64-78]). Variables related to epidemiology, microbiology, echocardiography and outcomes among both groups were analysed.

Results
The proportion of male patients was higher in those &lt;50 years (73.9% vs 64%; p&lt;0.001). Patients aged ≥50 years had more comorbidities. Time to diagnosis was longer in this group of patients (6.2 ± 1.5 vs 21.7 ± 14.12 days; p&lt;0.001). Proportion of community-acquired IE was higher in &lt;50-year episodes (64.4% vs 81%; p&lt;0.001). Intravenous drug use (IVU) was significantly more frequent in younger patients (22.6% vs 0.5%; p&lt;0.001). Likewise, tricuspid native valve IE was more common in patients &lt;50 years old (16.6% vs 4%; p&lt;0.001). Congenital heart disease (17.2% vs 2.7%; p&lt;0.001) and mitral valve prolapse (6.3% vs 3.8%; p=0.041) were more frequent in patients aged&lt;50 years. Conversely, prosthetic valve IE (38.4% vs 20.7%; p&lt;0.001) was more common in patients &gt;50 years. Streptococcus bovis (0.9% vs 5.6%; p&lt;0.001), enterococci (3% vs 12.6%; p=0.000), coagulase-negative staphylococci (9.9% vs 18.4%; p&lt;0.001) and gram-negative bacilli (1.2% vs 3.5%; p=0.028) infections were more frequent in ≥50-year adults, while the incidence of Streptococcus viridans (21.9% vs 10.7%; p&lt;0.001) and HACEK (1.2% vs 0.3%; p=0.03) infections was higher in the &lt;50-year group. Staphylococcus aureus IE was similar between the two groups (23.7% vs 19.4%; p=0.074). The presence of vegetations (87.4% vs 80.9%; p=0.005), as well as severe new valve regurgitation (42% vs 30.8%; p&lt;0.001) were more often found in &lt;50-year patients.
Acute heart failure (44.1% vs 59.5%; p&lt;0.001), acute kidney failure (27.3% vs 47.5%; p&lt;0.001) and septic shock (15.3% vs 20.9%; p=0.02) were more frequent in &gt;50-year group. No differences in frequency of cardiac surgery among both groups were found (61.9% vs 57.6%; p=0.147).
In-hospital mortality was significantly higher in ≥50-year patients (15.6% vs 29.2%; p&lt;0.001). Mortality remained higher in ≥50-year adults who underwent cardiac surgery (12.4% vs 23.3%; p=0.001) as well as those who did not undergo surgery (20.5% vs 37.2%; p&lt;0.001).

Conclusions
Patients aged &lt;50 years diagnosed with IE were more frequently male, and had a higher proportion of community-acquired infections. Congenital heart disease, mitral valve prolapse and IVU were more frequent in &lt;50-year adults. Streptococcus viridans infections were more frequent in this group of patients. In-hospital complications and mortality were lower compared to older patients, regardless of whether they underwent cardiac surgery.