Prosthetic Valve Endocarditis After Surgical Aortic Valve Replacement
Authors: Natalie Glaser, Veronica Jackson, Martin J. Holzmann, Anders Franco-Cereceda, Ulrik Sartipy
Journal: Circulation (2017)

Prosthetic valve endocarditis (PVE) is the most severe form of infective endocarditis and accounts for 20% of all cases of infective endocarditis. 1,2However, studies reporting the incidence of PVE after surgical aortic valve replacement (AVR) are scarce and based mainly on noncontemporary patient cohorts.Whether PVE affects biological and mechanical aortic valves to the same extent remains unknown.Therefore, we investigated the incidence and risk of PVE after surgical AVR in patients with biological and mechanical valves.This observational, nationwide, population-based cohort study was approved by the regional Human Research Ethics Committee in Stockholm, Sweden (Dnr.2016/1241-32) and is registered at ClinicalTrials.gov(Unique identifier: NCT02276950).No informed consent from patients was required.The SWEDE-HEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) register was used to obtain the study population.The unique personal identity number was used for cross-linking patient-level data from other national healthcare registers as described previously. 3All patients who underwent AVR with a biological or mechanical valve prosthesis in Sweden from January 1, 1995, to December 31, 2012, were included in the study.Patients with multiple valve surgeries were excluded.Person-time in days was counted from the date of surgery until the date of diagnosis of PVE, death, or end of follow-up (December 31, 2012, for PVE and March 24, 2014, for death).Cox regression was used to estimate the relative risk of PVE.Data management and statistical analyses were performed with Stata version 14.2 (StataCorp LP, College Station, TX).We included 26 580 patients; 16 426 (62%) received a bioprosthesis and 10 154 (38%) received a mechanical valve.Patients with bioprostheses were older (mean age, 74.1 versus 61.0 years) and had more comorbidities than patients with mechanical valves.During a mean follow-up of 6.2 years (maximum, 18.0 years), 940 patients (3.5%) were hospitalized for infective endocarditis.The event rates and crude and adjusted risks for PVE are shown in the Table .The incidence rate of PVE was 0.57% (95% confidence interval [CI], 0.54-0.61)per person-year.The incidence rates of PVE in biological and mechanical valves at 0 to 1, 1 to 5, 5 to 10, and 10 to 15 years' follow-up are shown in the Table.The risk of PVE was higher in patients with bioprostheses, both in the unadjusted analysis (hazard ratio [HR], 1.51; 95% CI, 1.31-1.74)and in the multivariable-adjusted analysis (HR, 1.54; 95% CI, 1.29-1.83).The results were consistent in age-stratified and agematched analyses.The adjusted risk of both early (within 1 year) endocarditis (HR, 1.65; 95% CI, 1.16-2.37)and late endocarditis (HR, 1.53; 95% CI, 1.25-1.86)was higher in patients with bioprostheses.In this nationwide, population-based cohort study, the incidence of PVE after AVR was 0.57% per person-year.The risk of PVE was highest during the first year after AVR; thereafter, the yearly rate of PVE was halved and remained stable during