Clinical Significance and Prognostic Value of Hemostasis Parameters in 337 Patients with Acute Infective Endocarditis

Clinical correlates of circulating small dense low-density lipoproteins in acute infective endocarditis

BACKGROUND AND AIM

Infective endocarditis (IE) is a complex thrombo-inflammatory disorder, the pathogenesis of which involves a multifaceted interplay between vascular damage and bacterial virulence factors. This study aimed to assess the prognostic role of small dense low-density lipoprotein (sdLDL) cholesterol in patients with IE and its correlation with various disease-related features.

METHODS

A cohort of 198 patients with definite IE was included in this study. Clinical, laboratory, and echocardiographic parameters were meticulously analyzed, with a specific focus on comorbidities. sdLDL levels were measured using stored plasma samples obtained upon admission during the acute phase of the disease.

RESULTS

The median level of sdLDL was 24 mg/dL [with an interquartile range of 17.9-35.2 mg/dL], and this value showed a statistically significant positive correlation with LDL/HDL cholesterol and triglycerides (p < 0.01 for all). Furthermore, a remarkable inverse correlation between C-reactive protein and D-dimer levels was observed (p < 0.0001). Univariate analysis revealed that patients with sdLDL levels ≤ 24 mg/dL had 2.75 times higher odds of in-hospital mortality (95% Confidence Interval:1.08-6.98, p = 0.031). In addition, nonsurvivors had significantly lower median sdLDL levels (19.7 vs. 26.0 mg/dL, p = 0.041). Lower sdLDL levels were also associated with embolic complications, larger vegetation size, and positive blood cultures for Staphylococci (p = 0.019, p = 0.022, and p < 0.001, respectively).

CONCLUSIONS

Low circulating sdLDL levels in the acute phase of IE were significantly correlated with unfavorable clinical outcomes. These results suggest that the sdLDL level may serve as an important marker of disease severity in IE and may represent a link between vascular damage, embolic complications, and disease progression.

Elevated International Normalized Ratio and Mortality in Hospitalized Patients Treated with Direct Oral Anticoagulants

BACKGROUND

Direct oral anticoagulants (DOACs) are associated with a prolongation of the prothrombin time and an increased international normalized ratio (INR). The clinical significance of these changes is unclear. This study aimed to examine the association between an elevated INR on admission and in-hospital death and long-term survival in patients treated with DOACs.

METHODS

Data were retrospectively retrieved from records of hospitalized patients at the Sheba Medical Center between November 2008 and July 2023. Patients were selected based on DOAC treatment, coagulation profile, and INR test done within 48 hours of hospitalization. The outcomes were in-hospital mortality and mortality in the year following hospitalization.

RESULTS

The study included 11,399 hospitalized patients treated with DOACs. Patients with elevated INR had a 180% higher risk of in-hospital mortality (adjusted odds ratio 2.80; 95% confidence interval, 2.30-3.39) and a 57% increased risk of death during the following year (adjusted hazard ratio 1.57; 95% confidence interval, 1.44-1.71). Similar results were observed in subgroup analyses for each DOAC.

CONCLUSIONS

An elevated INR on admission is associated with a higher risk for in-hospital death and increased risk for mortality during the first year following hospitalization in hospitalized patients treated with DOACs. This highlights that elevated INR levels in patients on DOACs should not be dismissed as laboratory variations due to DOAC treatment, as they may serve as a prognostic marker.

Host-Bacterium Interaction Mechanisms in Staphylococcus aureus Endocarditis: A Systematic Review

Staphylococci sp. are the most commonly associated pathogens in infective endocarditis, especially within high-income nations. This along with the increasing burden of healthcare, aging populations, and the protracted infection courses, contribute to a significant challenge for healthcare systems. A systematic review was conducted using relevant search criteria from PubMed, Ovid's version of MEDLINE, and EMBASE, and data were tabulated from randomized controlled trials (RCT), observational cohort studies, meta-analysis, and basic research articles. The review was registered with the OSF register of systematic reviews and followed the PRISMA reporting guidelines. Thirty-five studies met the inclusion criteria and were included in the final systematic review. The role of Staphylococcus aureus and its interaction with the protective shield and host protection functions was identified and highlighted in several studies. The interaction between infective endocarditis pathogens, vascular endothelium, and blood constituents was also explored, giving rise to the potential use of antiplatelets as preventative and/or curative agents. Several factors allow Staphylococcus aureus infections to proliferate within the host with numerous promoting and perpetuating agents. The complex interaction with the hosts' innate immunity also potentiates its virulence. The goal of this study is to attain a better understanding on the molecular pathways involved in infective endocarditis supported by S. aureus and whether therapeutic avenues for the prevention and treatment of IE can be obtained. The use of antibiotic-treated allogeneic tissues have marked antibacterial action, thereby becoming the ideal substitute in native and prosthetic valvular infections. However, the development of effective vaccines against S. aureus still requires in-depth studies.

Infective Endocarditis in High-Income Countries

Infective endocarditis remains an illness that carries a significant burden to healthcare resources. In recent times, there has been a shift from Streptococcus sp. to Staphylococcus sp. as the primary organism of interest. This has significant consequences, given the virulence of Staphylococcus and its propensity to form a biofilm, rendering non-surgical therapy ineffective. In addition, antibiotic resistance has affected treatment of this organism. The cohorts at most risk for Staphylococcal endocarditis are elderly patients with multiple comorbidities. The innovation of transcatheter technologies alongside other cardiac interventions such as implantable devices has contributed to the increased risk attributable to this cohort. We examined the pathophysiology of infective endocarditis carefully. Inter alia, the determinants of Staphylococcus aureus virulence, interaction with host immunity, as well as the discovery and emergence of a potential vaccine, were investigated. Furthermore, the potential role of prophylactic antibiotics during dental procedures was also evaluated. As rates of transcatheter device implantation increase, endocarditis is expected to increase, especially in this high-risk group. A high level of suspicion is needed alongside early initiation of therapy and referral to the heart team to improve outcomes.