Based on large population-based studies, the risk of prosthetic valve endocarditis (PVE) after surgical aortic valve replacement is 0.57% per person year. There is no causal link from asymptomatic bacteriuria (ASB) to PVE, however antibiotics are often prescribed in an abundance of caution given the catastrophic downside. The risk of PVE is yet to be determined in patients who receive a transcatheter aortic valve replacement (TAVR), but likely lower due to the minimally invasive approach. At our institution, ASB is heterogeneously treated with antibiotics prior to TAVR. Herein we quantified some untoward outcomes of treatment of ASB pre-TAVR.
A single-center retrospective study was conducted for patients who underwent TAVR between October 2012 and June 2017. Pre- and post-procedural urinalyses (UA), culture results, antibiotic regimens, development of resistance, symptoms of UTI, 30-day readmission rates, and 30- and 90-day mortality rates were collected.
296 patients with median age of 83 (range 49-97) underwent TAVR. 260 UAs with reflex to culture (137 of which reflexed) and 8 additional urine cultures (UC) were sent. 133 of 145 patients cultured had no documented symptoms. There were 44 patients with positive UC, of which 9 (20%) had symptoms. Of the 35 with ASB, 27 received antibiotics prior to TAVR (77%). Among those who were treated, there was 1 case of C. diff, 3 cases of development of resistance in an organism previously isolated and 3 cases of newly acquired MDRO. This amounts to a number needed to harm of 3.86. There were no cases of any of these outcomes, 30-day readmission or death within 90 days for the ASB patients who did not receive treatment. In the treatment group there was one case of bacteremia for which the causative organism was different from the organism isolated in UC.
In this small cohort of mostly elderly TAVR patients, the rate of ASB was high as expected and most were treated. We documented cases of potential harm associated with antibiotic treatment, and found no such harm episodes in the untreated group. Given the high number needed to harm and the historically low risk of PVE, antimicrobial stewardship experts should continue to encourage avoidance of antibiotics for ASB, including for patients undergoing invasive and minimally invasive cardiac procedures.
G. M. Andujar Vazquez, None
S. Doron, None
D. Snydman, None