Patient-prosthesis mismatch after transapical aortic valve implantation: incidence and impact on survival

Transcatheter aortic valve implantation (TAVI) has become an important therapeutic option for high-risk patients with severe aortic valve stenosis. Patient-prosthesis mismatch (P-PM) is an important determinant of morbidity and mortality after open aortic valve replacement. The objective of our study was to evaluate P-PM incidence and its impact on survival in a large cohort of patients treated with TAVI.

We retrospectively analyzed transesophageal echocardiographic data of 278 consecutive patients (Society of Thoracic Surgeons score 18.5 ± 15.3, age 80 ± 8 years) who underwent transapical TAVI with Edwards Sapien valves between April 2008 and March 2011. Effective orifice area was calculated using the continuity equation and indexed with body surface area (iEOA). P-PM was stratified as severe (iEOA < 0.65 cm(2)/cm(2)) and moderate (iEOA, 0.65-0.85 cm(2)/m(2)). Midterm survival (up to 30 months) was analyzed by Kaplan-Meier curves and log-rank tests. There was no P-PM in 181 (65.1%) patients; moderate P-PM was found in 76 (27.3%) patients and severe P-PM in 21 (7.6%). Thirty-day survival was 96.0%, 97.3%, and 90.5%. The 3-month survival was 91%, 90%, and 66%, respectively (P = .0013). Combination of severe P-PM with peak pressure gradients greater than 10 mm Hg further reduced the 3-month survival to 48%. Additionally, mean survival time in patients with an ejection fraction less than 50% was significantly shorter than in patients with an ejection fraction greater than 50% (20.8 ± 1.5 vs 24.1 ± 0.8 months; P = .027).

P-PM is found in patients undergoing transapical TAVI. Severe mismatch is accompanied by high early mortality, especially when combined with increased pressure gradients.