Temporal trends in infective endocarditis epidemiology from 2007 to 2013 in Olmsted County, MN

Abstract

The aim of this study is to determine if there have been contemporary shifts in infective endocarditis (IE) epidemiology in our local population; an analysis of cases from 2007 to 2013 was conducted. This is a population-based review of all adults (≥18 years) residing in Olmsted County, MN, with definite or possible IE using the Rochester Epidemiology Project from January 1, 2007, to December 31, 2013. We identified 51 cases of IE in Olmsted County, MN, between 2007 and 2013. Median age of IE cases was 68.8 years (interquartile range 55.6-76.5), and 41% were females. Age- and sex-adjusted incidence of IE was 7.4 (95% CI 5.3-9.4) cases per 100,000 person-years. From a multivariable Poisson regression model, incidence of IE did not change significantly during the study period (P = .222) but was significantly higher in males and those of older age (P < .001). The annual incidences (per 100,000 person-years) were 2.5 for Staphylococcus aureus, 1.1 for viridans group streptococci, 1.6 for Enterococcus species, and 0.8 for coagulase-negative staphylococci. Only 19.6% (10/51) of Olmsted County patients underwent valve surgery between 2007 and 2013 as compared with 44.4% (197/444) of non-Olmsted County patients treated at Mayo Clinic Rochester. In this population-based study, no significant change in the overall incidence of IE in Olmsted County, MN, between 2007 and 2013 was seen, and it was similar to that seen between 1970 and 2006. Male gender and older age were associated with increased IE risk. With a lesser extent of cases attributable to viridans group streptococcal IE compared with previous years, S aureus was the predominant pathogen in IE cases during 2007 to 2013. The relatively low valve surgery rate was disparate from that reported from large, tertiary care centers (including our own) with non-population-based cohorts, which are subject to referral bias and can influence the expected characterization of IE.