Observed to expected 30-day mortality as a benchmark for transcatheter aortic valve replacement

Matthew C. Henn, Alan Zajarias, Nishath Quader, Marc Sintek, John M. Lasala, Kelly Koogler, Marci S. Damiano, Puja Kachroo, D. Craig Miller, C. Ryan King, Spencer J. Melby, Marc R. Moon, Ralph J. Damiano, Hersh S. Maniar

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Objective: The observed-to-expected 30-day mortality ratio (O:E ratio) is a standard metric by which transcatheter aortic valve replacement (TAVR) trials have been evaluated. Early TAVR trials consistently demonstrated O:E ratio less than 0.6 after TAVR when based on the Society for Thoracic Surgery Predicted Risk of Mortality (STS-PROM) for surgical aortic valve replacement. Recent published results from the Transcatheter Valve Therapy (TVT) Registry have demonstrated O:E ratios of 1.0. We evaluated our own O:E ratios for TAVR to investigate this discordance. Methods: Data were collected prospectively for TAVR patients from 2008 through 2015 (N = 546) and were reviewed retrospectively. The observed mortality and STS-PROM were calculated to formulate O:E ratios and were compared over a variety of subgroups. Results: Overall, the O:E ratio for 30-day mortality was 0.4 and significantly less than 1 (P <.001; 95% confidence interval, 0.25-0.63). The O:E ratio relationship remained less than 0.5 for patients with low (STS-PROM < 4), moderate (STS-PROM = 4-8) and high risk (STS-PROM > 8). The O:E ratio was significantly higher for transapical patients (O:E ratio = 0.8) when compared with transfemoral patients (O:E ratio = 0.2). Lastly, O:E ratios for both commercial (O:E ratio = 0.5) and research (O:E ratio = 0.3) patients were similar (P =.337), and both were significantly less than 1 (P =.007 and P <.001, respectively). Conclusions: The STS-PROM consistently overestimated 30-day mortality after TAVR. Achieving an O:E ratio less than 0.6 may be a realistic goal for all TAVR programs. While an accurate and specific risk calculator for 30-day mortality after TAVR remains to be established, our data suggest that current TVT results are not acceptable for commercial TAVR and that programs with an O:E ratio greater than 0.6, based on the STS-PROM, should reevaluate internal processes to improve their results.

Original languageEnglish
Pages (from-to)874-882.e8
JournalJournal of Thoracic and Cardiovascular Surgery
Issue number3
StatePublished - Mar 2019


  • TAVR
  • aortic stenosis
  • aortic valve replacement
  • survival


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