The prevalence of pre-procedural kidney failure in patients undergoing transcatheter aortic valve replacement (TAVR) can be as high as 50 – 60% (stage 3 kidney failure or worse); it has been strongly associated with acute kidney deterioration and, ultimately, an increase of post TAVR mortality.

A recent meta-analyzis of several small studies carried out in a single center, reported a dialysis need rate of 5.8% associated with a 9 fold increase in mortality. However, at the same time, the German TAVR Registry confirmed mortality increase at 30 days (not at one year).

So far, there were no studies assessing whether the prognosis was different for patients requiring post procedural dialysis compared to patients already presenting fatal kidney failure prior procedure.

Also Read: “Incomplete Revascularization Associated to Mortality in TAVR”.

The UK TAVI Registry was established to report the outcomes of all TAVR procedures in the UK between 2007 and 2014. Data were gathered prospectively from 6464 patients at a mean follow up of 625 days. 

The proportion of patients that were on dialysis prior to TAVR remained constant in time, with 1.8%. However, the number of patients requiring new dialysis after procedure varied. Between 2007 and 2008, 6.1% of patients undergoing TAVR required post procedural dialysis, but in the period 2013-2014, it dropped to 2.3%.

The risk of new dialysis after procedure was independently associated to baseline kidney failure, ventricular dysfunction, diabetes, the use of the Edwards valve, an access other than femoral, the need of open surgery, and mild to severe residual aortic regurgitation.

Also Read: “Dual APT in TAVR: Is Single Better?”

The need of dialysis after TAVR was associated to major mortality both at 30 days (HR: 6.44; CI 95%: 4.87 to 8.53) and 4 years (HR: 3.54; CI 95%: 2.99 to 4.19; p<0.001).

Conclusion

The proportion of patients requiring dialysis after TAVR has dropped in time, but continues to be a factor clearly associated to mortality, both at short and long term.

Editorial Comment

The incidence of new dialysis decreased year after year regardless patient comorbidities or procedure characteristics (at least those recorded in the database), which is why we could think operator experience plays a major role.

All the factors involved in post procedural kidney failure were the ones typically associated to this complication; the only exception was valve type. Actually, it is difficult to explain why after multiple adjustments the balloon expandable valve from Edwards was associated to more post procedural kidney failure and this, in turn, did not raise mortality. Perhaps, the simplest explanation is that given the positive outcomes and the ample experience operators have with this device, they might be inclined to use it in the most challenging cases, more prone to develop kidney failure.

Título original: Dialysis Following Transcatheter Aortic Valve Implantation, Risk Factors and Outcomes. An Analysis from the UK TAVI Registry (Transcatheter Aortic Valve Implantation) Registry.

Referencia: Charles J. Ferro et al. JAmCollCardiol Intv 2017. Article in press.

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