A pacemaker infection was diagnosed in 19 (9.4%) patients. There were 34 (16.8%) mechanical valves and 112 (55.4%) bioprosthetic valves implanted. Valvular plasties were performed in selleck catalog 66 patients (32.7%). One patient (0.5%) had a concomitant coronary artery bypass graft, and fourteen (6.9%) underwent ascending aorta replacement using a prosthetic tube. Median duration of extracorporeal circulation was 118 (85 to 163) minutes, and median duration of aortic cross-clamping was 89 (65 to 121) minutes. Circulatory arrest was necessary in five (2.5%) patients. A second operation (or more) was necessary in 29 (14.4%) patients. The main reasons were: tamponnade (n = 12, 41.4%), valve dysfunction (n = 6, 20.7%) and mediastinitis (n = 4, 13.8%).MicrobiologyThe causative pathogens are presented in Table 2.

The three most frequently involved species were: streptococci (n = 84, 41.6%), staphylococci (n = 56, 27.8%) and enterococci (n = 18, 8.9%). Blood cultures were positive in 155 (76.7%) patients.Table 2MicrobiologyRenal function and prognosisSixty-five patients (32.2%) presented with AKI before surgery, and 137(67.8%) had normal renal function before surgery. Of the 65 patients with pre-operative AKI, 52 (80%) were in AKIN stage 1, 9 (13.8%) in stage 2 and 4 (6.2%) in stage 3. A flow chart depicting the evaluation of renal function throughout the peri-operative period is provided in Figure 1. The evolution of serum creatinine in the peri-operative period is separately described in Figure 2.Figure 1Flow chart of patients. AKI, acute kidney injury.

Figure 2Evolution of serum creatinine during the peri-operative period. AKI, acute kidney injury.A total of 120 (59.4%) patients met the criteria for AKI in the post-operative period: 64 (46.7%) of the 137 patients without pre-operative AKI and 56 (86.1%) of the 65 patients with pre-operative AKI. Among the 65 patients with pre-operative AKI, 9 (13.8%) recovered during the 7 days following surgery, 29 (44.6%) had no AKI progression, and 27 (41.6%) experienced AKI progression (that is, worsening in their AKI stage).A total of 20 patients (9.9%) required RRT during the post-operative ICU stay. The delay between ICU admission and the initiation of RRT was 1.5 (1 to 3) days.Association between acute kidney injury and patients�� outcomesThirty patients (14.8%) died during their hospital stay.

Mortality was associated with the presence/absence of AKI. The association was not statistically significant when considering pre-operative AKI only: 16 (11.7%) patients Batimastat without pre-operative AKI died versus 14 (21.5%) patients with pre-operative AKI (P = 0.09 for univariate analysis). However, the association between post-operative AKI and mortality was statistically significant: 2 (2.4%) patients without post-operative AKI died, and 28 (23.3%) patients with post-operative AKI died during their hospital stay (P <0.001 for univariate analysis). AKI stage was also associated with mortality: 18 (52.