Longitudinal Study of the Effects of Bacteremia and Sepsis on 5-year Risk of Cardiovascular Events

Abstract

Background: The long-term and cumulative effect of multiple episodes of bacteremia and sepsis across multiple hospitalizations on the development of cardiovascular (CV) events is uncertain.

Methods: We conducted a longitudinal study of 156 380 hospitalizations in 47 009 patients (≥18 years old) who had at least 2 inpatient admissions at an academic tertiary care center in St Louis, Missouri, from 1 January 2008 through 31 December 2012. We used marginal structural models, estimated by inverse probability weighting (IPW) of bacteremia or sepsis and IPW of censoring, to estimate the marginal causal effects of bacteremia and sepsis on developing the first observed incident CV event, including stroke, transient ischemic attack, and myocardial infarction (MI), during the study period.

Results: Bacteremia and sepsis occurred during 4923 (3.1%) and 5544 (3.5%) hospitalizations among 3932 (8.4%) and 4474 (9.5%) patients, respectively. CV events occurred in 414 (10.5%) and 538 (12.0%) patients with prior episodes of bacteremia or sepsis, respectively, vs 3087 (7.2%) and 2963 (7.0%) patients without prior episodes of bacteremia or sepsis. The causal odds of experiencing a CV event was 1.52-fold (95% confidence interval [CI], 1.21- to 1.90-fold) and 2.39-fold (95% CI, 1.88- to 3.03-fold) higher in patients with prior instances of bacteremia or sepsis, respectively, compared to those without. Prior instances of septic shock resulted in a 6.91-fold (95% CI, 5.34- to 8.93-fold) increase in the odds of MI.

Conclusions: Prior instances of bacteremia and sepsis substantially increase the 5-year risk of CV events.

Keywords: bloodstream infection; causal inference; inverse probability weighting; marginal structural model; time-varying confounding.

Figure 1.

A directed acyclic graph for the time-varying confounding effects of risk factors, comorbidities, medications, and covariates that are also intermediate variables for the effects of bacteremia and sepsis on cardiovascular events. Time-varying exposures, time-varying confounders, and outcome are indicated by A, L, and Y, respectively. Subscripts indicate the time points.