AKI after Transcatheter or Surgical Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) is an alternative to surgical aortic valve replacement (SAVR) for patients with symptomatic severe aortic stenosis who are at high risk of perioperative mortality. Previous studies showed increased risk of postoperative AKI with TAVR, but it is unclear whether differences in patient risk profiles confounded the results. To conduct a propensity-matched study, we identified all adult patients undergoing isolated aortic valve replacement for aortic stenosis at Mayo Clinic Hospital in Rochester, Minnesota from January 1, 2008 to June 30, 2014. Using propensity score matching on the basis of clinical characteristics and preoperative variables, we compared the postoperative incidence of AKI, defined by Kidney Disease Improving Global Outcomes guidelines, and major adverse kidney events in patients treated with TAVR with that in patients treated with SAVR. Major adverse kidney events were the composite of in-hospital mortality, use of RRT, and persistent elevated serum creatinine ≥200% from baseline at hospital discharge. Of 1563 eligible patients, 195 matched pairs (390 patients) were created. In the matched cohort, baseline characteristics, including Society of Thoracic Surgeons risk score and eGFR, were comparable between the two groups. Furthermore, no significant differences existed between the TAVR and SAVR groups in postoperative AKI (24.1% versus 29.7%; P=0.21), major adverse kidney events (2.1% versus 1.5%; P=0.70), or mortality >6 months after surgery (6.0% versus 8.3%; P=0.51). Thus, TAVR did not affect postoperative AKI risk. Because it is less invasive than SAVR, TAVR may be preferred in high-risk individuals.