Repeat Infective Endocarditis in Persons Who Inject Drugs: “Take Another Little Piece of my Heart”*

Abstract

BackgroundInjection drug use (IDU) is a major risk factor for infective endocarditis (IE). Few data exist on repeat IE (rIE) in persons who inject drugs (PWID).MethodsPatients ≥18 years old seen at Wake Forest Baptist Medical Center from 2004 to 2017 who met Duke criteria for IE and who self-reported IDU in the 3 months before admission were identified. The subset of PWID who developed rIE, defined as another episode of IE at least 10 weeks after diagnosis of the first episode, was then reviewed.ResultsOf the 87 PWID who survived their first episode of IE, 22 (25.3%) experienced rIE and 77.3% had rIE within a year of the first episode. All patients who experienced rIE resumed IDU between episodes of IE. Of the patients with rIE, 54.5% had an infection caused by S. aureus and 22.7% required surgical intervention. Mortality at 1 year was 36.3%. Compared with their first IE episode, patients with rIE had fewer S. aureus infections (P = .01). Compared with PWID who experienced single-episode IE, intravenous prescription opioid use (P = .01), surgery (P < .01), tricuspid valve involvement (P = .02), and polymicrobial infection (P = .03) occurred more often during first episodes of IE in individuals who then developed rIE.ConclusionsrIE is common among IDU-related IE and confers a high 1-year mortality rate. The microbiology of rIE is varied, with S. aureus being less frequently isolated. More studies on modification of social and clinical risk factors are needed to prevent rIE.

Recurrent Endocarditis in Persons Who Inject Drugs

“…The rate of recurrent endocarditis among PWID in our cohort was 32%, with 68 patients experiencing a second episode. This is higher than rates that have previously been reported in non–drug user populations (which range from 2.4% to 10.9%) [26] but is similar to a cohort of PWID from the 1970s where the recurrence rate was 41% [27] and a more contemporary population in North Carolina where the recurrence rate was 25.3% in PWID [9]. It remains unclear whether any clinical factors increase the likelihood of experiencing a second episode of endocarditis, beyond continued injection drug use.…”

“…Interestingly, the risk of recurrent endocarditis in PWID has been inconsistent. It has been shown that repeat endocarditis is associated with injection drug use [9, 25]; however, older studies before the recent opioid crisis did not note an association of recurrent endocarditis with injection drug use [17]. We present the largest case series of recurrent endocarditis among PWID to date.…”

“…Recurrence is defined as repeated IE episodes at least 6 months apart or caused by different microorganisms [7, 8]. In the literature, recurrent IE episodes in PWID affect 5.6%–25% of patients [9, 10] and recurrent episodes were reported in 1 small study to be associated with increased morbidity and mortality [9].…”

“…Few studies have reported on the microbial etiology and outcomes of recurrent IE episodes [7, 17], likely due to its rarity in most patient populations. Only 1 small study has recently been published on recurrent IE in PWID [9]. Given the current opioid epidemic and its association with IE, there is an urgent need for data on this population.…”

Risk factors of infective endocarditis in persons who inject drugs

“…There has been very little data assessing the detailed injection practices associated with developing IE. The literature primarily studies the clinical and epidemiological characteristics of PWID developing IE [3,5,7,26,27]. Some studies assessing injection practices of PWID are in relation to the development of skin and soft tissue infections [28] or infections in general [14,20,29].…”