Clinical characteristics, microbiology, and outcomes of infective endocarditis in Qatar
Authors: Zaqout Ahmed , Mohammed Shaban , Thapur Maliha , Al-Soub Hussam , Al-Maslamani Muna A. , Al-Khal Abdullatif , Omrani Ali S. 
Published: October 2020

Background: Infective endocarditis (IE) is a serious and potentially life-threatening disease. The epidemiology, treatment options, and outcomes have changed considerably over the last two decades. The aim of the study was to describe the epidemiology, clinical characteristics, and outcomes of patients with IE in Qatar.

Methods: Patients were identified from Hamad Medical Corporation hospitals’ electronic records, the national referral center for the State of Qatar. We included those aged ≥ 18 years with Duke Criteria-based diagnosis of IE during the period from January 2015 to September 2017. Demographic and clinical data were retrieved. Descriptive statistics were performed, and logistic regression analysis was used to describe the relationship between patient characteristics and all-cause in-hospital mortality. All potentially relevant variables were included in the univariate analysis, while those with p < 0.1 in the univariate logistic regression model were included in the multivariate analysis. For the final model, we calculated odds ratios (OR) adjusted for each of the variables included, along with their 95% confidence intervals (95% CI). Data were analyzed using STATA software version 15 (StataCorp, College Station, Texas, USA). The study was approved by the Institutional Research Board with a waiver for informed consent.

Results: Fifty-seven cases were included, of which 70% were males. The mean age was 51 years ( ± 16.8 years). Eleven (19%) were associated with prosthetic valves, and 6 (11%) with implantable cardiac devices. Fever (84%), dyspnea (46%), and heart failure (37%) were the most common presentations. Only 58% of patients had known preexisting valvular heart disease or an intracardiac device. Skin infections (10 patients, 18%) were the most prevalent portals of infection, followed by venous catheters, recent valve surgery, and implantable cardiac devices. Staphylococci were implicated in 19 (34%) and Streptococcaceae in 9 (16%) patients, whereas 21 (37%) patients were culture negative. Left-side IE (49 patients, 86%) was predominant. Acute kidney injury (AKI) (17 patients, 30%) and heart failure (11 patients, 19%) were common complications. The majority of patients received targeted antimicrobial therapy with at least two active agents. Only 9 (16%) patients underwent surgical intervention. Fourteen (25%) patients died of any cause before hospital discharge. Logistic regression analysis identified septic shock [OR 57.8, 95% CI 2.6–1360.2; p < 0.01] and AKI OR 33.9, 95% CI 2.9–398.1; p < 0.01) as the only risk factors independently associated with in-hospital mortality.

Conclusion: Staphylococci are the most common microbiological cause of IE in Qatar. Surgical intervention is uncommon, and mortality is relatively high. Our findings suggest that efforts should be directed toward improving IE prevention strategies in high-risk patients, encouraging early microbiological investigations and improving medical and surgical management.