Current Surgical Risk Scores Overestimate Risk in Minimally Invasive Aortic Valve Replacement

Ahmed Alnajar, Subhasis Chatterjee, Brendan P. Chou, Mariam Khabsa, Madeline Rippstein, Vei Vei Lee, Angelo La Pietra, Joseph Lamelas

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Objective: Risk-scoring systems for surgical aortic valve replacement (AVR) were largely derived from sternotomy cases. We evaluated the accuracy of current risk scores in predicting outcomes after minimally invasive AVR (mini-AVR). Because transcatheter AVR (TAVR) is being considered for use in low-risk patients with aortic stenosis, accurate mini-AVR risk assessment is necessary. Methods: We reviewed 1,018 consecutive isolated mini-AVR cases (2009 to 2015). After excluding patients with Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) scores ≥4, we calculated each patient’s European System for Cardiac Operative Risk Evaluation (EuroSCORE) II, TAVR Risk Score (TAVR-RS), and age, creatinine, and ejection fraction score (ACEF). We compared all 4 scores’ accuracy in predicting mini-AVR 30-day mortality by computing each score’s observed-to-expected mortality ratio (O:E). Area under the receiver operating characteristic (ROC) curves tested discrimination, and the Hosmer–Lemeshow goodness-of-fit tested calibration. Results: Among 941 patients (mean age, 72 ± 12 years), 6 deaths occurred within 30 days (actual mortality rate, 0.6%). All 4 scoring systems overpredicted expected mortality after mini-AVR: ACEF (1.4%), EuroSCORE II (1.9%), STS-PROM (2.0%), and TAVR-RS (2.1%). STS-PROM best estimated risk for patients with STS-PROM scores 0 to <1 (0.6 O:E), ACEF for patients with STS-PROM scores 2 to <3 (0.6 O:E), and TAVR-RS for patients with STS-PROM scores 3 to <4 (0.7 O:E). ROC curves showed only fair discrimination and calibration across all risk scores. Conclusions: In low-risk patients who underwent mini-AVR, current surgical scoring systems overpredicted mortality 2-to-3-fold. Alternative dedicated scoring systems for mini-AVR are needed for more accurate outcomes assessment.

Original languageEnglish (US)
Pages (from-to)43-51
Number of pages9
JournalInnovations: Technology and Techniques in Cardiothoracic and Vascular Surgery
Issue number1
StatePublished - Jan 2021
Externally publishedYes


  • aortic valve replacement
  • minimally invasive surgery
  • outcomes
  • risk analysis
  • risk modeling

ASJC Scopus subject areas

  • Surgery
  • Pulmonary and Respiratory Medicine
  • Cardiology and Cardiovascular Medicine


Dive into the research topics of 'Current Surgical Risk Scores Overestimate Risk in Minimally Invasive Aortic Valve Replacement'. Together they form a unique fingerprint.

Cite this