OBJECTIVES : Latest clinical guidelines recommend biological prostheses as a reasonable choice in patients ≥65 years requiring aortic valve replacement (AVR). The aim is to compare clinical outcomes (major adverse events survival at short and long term) and resource-consumption (health resources, anticoagulation rates and post-surgery length of stay in ward -LoS- and intensive care unit -ICU-) between mechanical (MAVI) and biological aortic valve implants (BAVI) in AVR.

METHODS : An observational, retrospective study including all consecutive patients undergoing AVR with an isolated BAVI or MAVI between 2003 and 2016. Patients were followed-up until June 30th, 2020. In this analysis, patients >65y were considered (n=1,055: 881 BAVI, 174 MAVI). Propensity score matching and multivariate competing risks models with HR correction were applied to estimate differences in the clinical outcomes. Besides, non-parametric tests and multivariate count models were conducted to evaluate differences in resource-consumption.

RESULTS : At short term, low complication rates in both types of implants were observed among the matched sample. At long term, no differences in all-cause mortality were found (HR=0.848; CI: 0.663—1.086; p>0.1). Furthermore, BAVIs were associated to a lower prevalence of postoperative anticoagulant treatment (31.6% vs. 82.8%; p<0.01). Regarding ICU, BAVI were found to have a 51% shorter stay until discharge (p<0.01) than patients with MAVI. Analyses by time periods showed a downward trend in ward and ICU stays. During follow-up, other healthcare resources (i.e., number of echocardiograms, visits to cardiologist) were higher among BAVI.

CONCLUSIONS : Low perioperative rates of complications in both MAVI and BAVI were found, and long-term survival was similar in patients over 65y of age. BAVI was associated with a shorter post-surgery ICU stay and lower rates of anticoagulants, which might be related to recent advancements in biological implant technology and should be incorporated in further economic analyses.