HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort

PLoS One. 2013 May 17;8(5):e63181. doi: 10.1371/journal.pone.0063181. Print 2013.


The HACEK organisms (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) are rare causes of infective endocarditis (IE). The objective of this study is to describe the clinical characteristics and outcomes of patients with HACEK endocarditis (HE) in a large multi-national cohort. Patients hospitalized with definite or possible infective endocarditis by the International Collaboration on Endocarditis Prospective Cohort Study in 64 hospitals from 28 countries were included and characteristics of HE patients compared with IE due to other pathogens. Of 5591 patients enrolled, 77 (1.4%) had HE. HE was associated with a younger age (47 vs. 61 years; p<0.001), a higher prevalence of immunologic/vascular manifestations (32% vs. 20%; p<0.008) and stroke (25% vs. 17% p = 0.05) but a lower prevalence of congestive heart failure (15% vs. 30%; p = 0.004), death in-hospital (4% vs. 18%; p = 0.001) or after 1 year follow-up (6% vs. 20%; p = 0.01) than IE due to other pathogens (n = 5514). On multivariable analysis, stroke was associated with mitral valve vegetations (OR 3.60; CI 1.34-9.65; p<0.01) and younger age (OR 0.62; CI 0.49-0.90; p<0.01). The overall outcome of HE was excellent with the in-hospital mortality (4%) significantly better than for non-HE (18%; p<0.001). Prosthetic valve endocarditis was more common in HE (35%) than non-HE (24%). The outcome of prosthetic valve and native valve HE was excellent whether treated medically or with surgery. Current treatment is very successful for the management of both native valve prosthetic valve HE but further studies are needed to determine why HE has a predilection for younger people and to cause stroke. The small number of patients and observational design limit inferences on treatment strategies. Self selection of study sites limits epidemiological inferences.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aggregatibacter
  • Cardiobacterium
  • Cohort Studies
  • Eikenella corrodens
  • Endocarditis, Bacterial / epidemiology*
  • Endocarditis, Bacterial / microbiology
  • Endocarditis, Bacterial / physiopathology*
  • Endocarditis, Bacterial / therapy*
  • Haemophilus
  • Humans
  • Kingella
  • Odds Ratio
  • Prevalence
  • Statistics, Nonparametric
  • Treatment Outcome

Grant support

This work was supported by the American Heart Association 0675027N (VHC), educational grants from International Society of Cardiovascular Infectious Diseases, International Society of Chemotherapy, the “Ministerio de Sanidad y Consumo, Instituto de Salud Carlos III”, Madrid, Spain, and the Spanish Network for Research in Infectious Diseases (REIPI RD06/0008) (MA, CGDM) and the Fundación Privada Máximo Soriano Jiménez (Barcelona, Spain) (CGDM). The funders had no role in study design, data collection adn analysis, decision to publish, or preparation of the manuscript.