Abstract 17570: Hemodynamic Determinants of Long Term Functional Capacity in Patients Undergoing Mitral Valve Annuloplasty or Mitral Valve Replacement for Ischemic Mitral Regurgitation
Background: Mitral valve annuloplasty (MVA) or mitral valve replacement (MVR) are conventional approaches for the treatment of patients with ischemic mitral regurgitation (IMR). Few data exist about the long-term impact of these strategies on exercise hemodynamic parameters and functional capacity.
Objective: To evaluate the relationship between exercise mitral valve hemodynamic performance and changes in functional capacity following surgery.
Methods: An exercise stress echocardiography (ESE) was performed in 120 patients with IMR, following MVA or MVR. Pre-operative and late postoperative (60 ± 10 months) functional capacity was assessed using 6-minute walking distance (6MWD).
Results: The patients were matched (1:1) for age, gender and studied in 2 groups according to the surgical procedure: MVA (n=60) vs. MVR (n=60). There was no significant difference between the 2 groups regarding baseline clinical data. Exercise mean, peak transmitral gradient and systolic arterial pulmonary pressure (SPAP) were significantly higher in MVA group, as compared to MVR (11± 3.6 vs. 9 ± 3.5 mmHg, p = 0.006; 20.7 ± 6.5 vs. 16.5 ± 8.8 mmHg, p = 0.008; 56 ± 10 vs. 41 ± 10 mmHg, p = 0.001, respectively), despite significant lower EF and cardiac output (46 ± 7 vs. 49 ± 5 %, p = 0.01, 7.5 ± 1.5 vs. 8.8 ± 1.4 l/min, p = 0.001, respectively).
Effective orifice area (EOA) were significantly lower in MVA as compared to MVR (1.9 ± 0.5 vs. 2.3 ± 0.4, p = 0.001). A significant net improvement in 6MWD was only observed in the MVR group (+36.7 ± 39 m vs. -24 +/- 49 m, p < 0.001), and was significantly correlated with EOA (r = 0.32, p = 0.001), EF ( r = 0.44, p = 0.001) and SPAP (r = - 0.5, p = 0.001). On multivariate analysis, surgical strategy (MVA vs. MVR) was the only independent determinant of both reduced absolute and relative 6MWD changes.
Conclusions: In patients with IMR, MVR seems to show a better functional capacity, as compared to MVA. These findings are also related to a better exercise haemodynamic performance of MVR.
- © 2013 by American Heart Association, Inc.