Infective Endocarditis due to Non-HACEK Gram-Negative Bacilli: Clinical Characteristics and Risk Factors from a Prospective Multicenter Brazilian Cohort

Abstract

Background: Non-HACEK Gram-negative bacilli (NGNB) infective endocarditis (IE) has a growing frequency. We aimed to describe cases of NGNB IE and find associated risk factors. Methods: We conducted a prospective observational study of consecutive patients with definitive IE according to the modified Duke criteria in four institutions in Brazil. Results: Of 1154 adult patients enrolled, 38 (3.29%) had IE due to NGNB. Median age was 57 years, males predominated, accounting for 25/38 (65.8%). Most common etiologies were Pseudomonas aeruginosa and Klebsiella spp. (8 episodes, 21% each). Worsening heart failure occurred in 18/38 (47.4%). Higher prevalence of embolic events was found (55,3%), mostly to the central nervous system 7/38 (18.4%). Vegetations were most commonly on aortic valves 17/38 (44.7%). Recent healthcare exposure was found in 52.6% and a central venous catheter (CVC) in 13/38 (34.2%). Overall mortality was 19/38 (50%). Indwelling CVC (OR 5.93; 95% CI, 1.29 to 27.3; p = 0.017), hemodialysis (OR 16.2; 95% CI, 1.78 to 147; p = 0.008) and chronic kidney disease (OR 4.8; 95% IC, 1.2 to 19.1, p = 0.049) were identified as risk factors for mortality. Conclusions: The rate of IE due to NGNB was similar to that in previous studies. Enterobacterales and P. aeruginosa were the most common etiologies. NGNB IE was associated with central venous catheters, prosthetic valves, intracardiac devices and hemodialysis and had a high mortality rate.

Infective endocarditis: comments on the 2023 Duke-International Society for Cardiovascular Infectious Diseases Criteria for Infective Endocarditis: Updating the Modified Duke Criteria

“…However, a recent study across 13 hospitals in Pennsylvania, USA (26), identified 123 cases through electronic records between April 2010 and December 2021, and found a high proportion of intravenous drug users (52%) and of S.marcescens, similar to older series from the 80's and 90's in which drug users prevailed. Other series of non-HACEK Gram negative IE did not show a predominance of S.marcescens nor of P.aeruginosa; E.coli and K.pneumoniae figure more frequently or just as frequently as these do (25,(27)(28)(29)(30)(31)(32)(33)(34). Although it is positive to stimulate clinicians to think of IE and pursue the diagnosis with TOE or PET CT, this will add a great deal of cost and invasive procedures.…”

“…Serratia marcescens and Pseudomonas aeruginosa, although not rare in BSI, are uncommon causes of IE. Non-HACEK Gram negative IE represents approximately 2% to 6% of all cases of IE, and has been associated with healthcare, including urinary tract procedures, intravenous lines and early prosthetic valve IE (25). However, a recent study across 13 hospitals in Pennsylvania, USA (26), identified 123 cases through electronic records between April 2010 and December 2021, and found a high proportion of intravenous drug users (52%) and of S.marcescens, similar to older series from the 80's and 90's in which drug users prevailed.…”