What is the Relationship Between Dialysis and Mortality After TAVR?

While dialysis after transcatheter aortic valve replacement (TAVR) is associated with increased mortality, the proportion of patients needing it has decreased over time, according to research published Oct. 16 in JACC: Cardiovascular Interventions.

Charles J. Ferro, MD, et al., collected data from 6,464 patients in the UK TAVI Registry. Over a median follow-up of 625 days, 202 (3.1 percent) patients required dialysis for the first time after the TAVR procedure. Over time, the proportion of patients who needed new dialysis after TAVR has fallen, from 6.1 percent during the period of 2007-2008 to 2.3 percent during the period of 2013-2014.

A total of 2,486 (37 percent) patients died during follow-up. Of these, 314 died in hospital: 223 (3.7 percent) patients with no dialysis requirement, nine (7.8 percent) patients on dialysis before the procedure and 82 (40.6 percent) patients requiring dialysis after TAVR (p < 0.001). A new requirement for dialysis after TAVR was associated with a >6-fold increased risk of mortality at 30 days compared with non–dialysis-requiring control subjects, whereas patients established on dialysis before TAVR had a >2-fold increased risk.

The risk of new dialysis requirement after TAVR was independently associated with lower baseline renal function, year of procedure, impaired left ventricular function, diabetes, use of an Edwards valve, a nontransfemoral approach, need for open surgery and moderate-to-severe aortic regurgitation after the procedure. Requirement for new dialysis after TAVR was associated with higher mortality at 30 days (hazard ratio, 6.44; 95 percent confidence interval, 4.87-8.53) and at four years (hazard ratio, 3.54; 95 percent confidence interval, 2.99-4.19; p < 0.001 for all) compared with patients without dialysis requirement.

In an accompanying editorial comment, Anand Prasad MD, FACC, and Marlene Garcia MD, write, "Given the marked increase in mortality in patients who end up on dialysis post-TAVR, there needs to be a greater urgency and focus on the role of chronic kidney disease in these patients. Given the established role of contrast dye as a nephrotoxic agent and the growing evidence that both the route of valve delivery and perhaps the valve type may influence renal outcomes, future registries should be sufficiently granular in their data extraction to capture variables related to these factors. Although the role of embolic protection remains of interest in preventing stroke during TAVR, we should also look further down the aorta to the renal arteries as another vascular bed worthy of protection."

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and VHD, Interventions and Structural Heart Disease

Keywords: Aortic Valve Insufficiency, Transcatheter Aortic Valve Replacement, Renal Artery, Confidence Intervals, Ventricular Function, Left, Follow-Up Studies, Registries, Renal Insufficiency, Chronic, Aorta, Kidney, Diabetes Mellitus, Stroke

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