The following is a response to the Letter to the Editor by Cong et al.

Objective: To determine the predictors of postoperative AKI following non-emergent cardiac surgery among patients with variable preoperative eGFR levels. Methods: Retrospective study of patients who underwent elective or in-hospital cardiac surgical procedures performed between January 2006 and November 2015. The procedures included isolated CABG, isolated AVR or combined CABG and AVR. The primary outcome AKI (any stage) following non-emergent cardiac surgery utilizing the 2012 KDIGO criteria. Patients were categorized based the following renal outcomes: mild AKI, severe AKI (KDIGO stage 2 or 3) and post-operative dialysis.. Results: A total of 6713 patients were included in our study. The mean age was 66.8 years (SD ± 10.3), with 76.2% being males. A total of 4487 patients had normal or mildly decreased eGFR (G1 or G2) preoperatively (66.8%), while 1960 patients were in the G3 category (29.1%). Only 266 patients (3.9%) had G4 or worse renal function. A total of 1489 (28.5%) patients experienced post-operative AKI. The need for postoperative dialysis occurred in 4.2% of the AKI subgroup. In-hospital mortality was higher among the AKI subgroup (7.3% vs 0.5%, p<0.0001). In an adjusted model, a lower pre-operative eGFR category was the strongest predictor of AKI. A practical scorecard for the preoperative estimation of severe AKI for non-emergent cardiac procedures incorporating these parameters was developed. Conclusions: Preoperative eGFR is the strongest predictor of post-operative AKI in individuals undergoing non-emergent cardiac surgery. A practical scorecard incorporating preoperative predictors of AKI may allow informed decision making and to predict AKI following non-emergent cardiac surgery

Background The Carpentier-Edwards Perimount valves have a proven track record in aortic valve replacement: good durability, hemodynamic performance, rates of survival, and infrequent valve-related complications and PPM. The St. Jude Medical Trifecta is a newer valve that has shown comparable early and midterm outcomes. Studies show reoperation rates of Trifecta are comparable to Perimount valves, with a few recent studies bringing into focus early SVD, and increased midterm SVD in younger patients. Given that midterm data for Trifecta is still sparse, we wanted to confirm the early low reoperation rates of Trifecta persist over time compared to Perimount. Methods The Maritime Heart Centre Database was searched for isolated AVR or AVR+CABG between January 2011 and December 2016. Primary end point of the study was all-cause reoperation rate. Results 711 Perimount and 453 Trifecta implantations were included. The reoperation hazards were determined for age: 0.96 (0.92-0.99, p=0.02), female (vs male): 0.35 (0.08-1.53, p=0.16), smoker (vs non-smoker): 2.44 (0.85-7.02, p=0.1), and Trifecta (vs Perimount): 2.68 (0.97-7.39, p=0.06). Kaplan-Meier survival analysis in subgroups—age < 60, age ≥ 60, male, female, smoker, and non-smoker—showed Perimount having lower reoperation rates than Trifecta in patient younger than 60 (p=0.02) and those with smoking history (p<0.01). Conclusions The rates of reoperation of Perimount and Trifecta were comparable, with Trifecta showing higher rates in patients younger than 60 years, and current smokers. Continued diligence and further independent reporting of midterm reoperation and SVD rates of the Trifecta, including detailed echocardiographic follow up, are needed to confirm these findings.