Effect of preoperative low serum albumin on postoperative complications and early mortality in patients undergoing transcatheter aortic valve replacement

Background: Patients undergoing transcatheter aortic valve replacement (TAVR) are mostly elderly patients with substantial comorbidities. Established risk scores are not validated for TAVR and collectives with elderly patients making periprocedural risk stratification difficult. Serum albumin is known to be an indicator for malnutrition and frailty and is simple to measure, independent of physician's bias. Using serum albumin as a preoperative marker for postoperative complications might help estimating morbidity and mortality of these patients.

Methods: A total of 457 patients with severe symptomatic aortic stenosis undergoing TAVR at our institution in a period from January 2014 to December 2015 were included in this retrospective study. Baseline characteristics as well as preoperative laboratory parameters were registered. Postoperative morbidity and 30-day mortality were analyzed as primary end points. Enrolled patients with preoperative low serum albumin (<3.5 g/dL) were compared with those revealing normal serum albumin (≥3.5 g/dL).

Results: Among 457 patients, 51 (11%) presented pre-procedural low serum albumin and 406 (89%) had normal serum albumin. Patients' mean age was 81±6 years and 50% of them were male. Postoperative complications such as requirement of blood transfusions (63% versus 33%, P<0.001), infection (53% versus 24%, P<0.001), acute kidney injury (41% versus 19%, P=0.001) and 30-day mortality (10% versus 3%, P=0.045) showed significant differences between preoperative low and normal albumin groups.

Conclusions: Preoperative low serum albumin might be an indicator for higher morbidity and mortality in patients undergoing TAVR.