Mechanical versus bioprosthetic valves for patients with chronic ischemic mitral regurgitation

1. MECHANICAL VERSUS BIOLOGICAL PROSTHESES FOR CHRONIC
ISCHAEMIC MITRAL REGURGITATION: A LONG-TERM HEMODYNAMIC
AND FUNCTIONAL CAPACITY COMPARISON
Carlo Fino MD
Cardiovascular Department
Azienda Ospedaliera Papa Giovanni XXIII
Bergamo, Italy

2. Background
• Chronic ischemic mitral regurgitation is a
common complication in patients with
coronary artery disease
• The outcome is poor
• The treatment is still debated
Lamas et al Circulation 1997
Magne et a Circulation 2009
Lorusso et al JTCVS 2013

3. Summary of Recommendations for
Chronic Severe Ischemic MR
COR: Class of Recommendation LOE: level of Evidence
AHA/ACC Guideline for the Management of Patients
With Valvular Heart Disease, JACC 2014

4. …Replacement provided a more durable
correction of mitral regurgitation, but there was
no significant between-group difference in
clinical outcomes…
Acker M.A et al

5. Complete chordal-sparing mitral valve replacement
Pibarot P et al, Heart 2006

6. Cardiovascular Assessment
• 6-MWT is a practical, simple, inexpensive test, which does
not require any exercise equipment.
• It has been proposed both as a functional status indicator
and as an outcome measure in various categories of
patients (i.e postcardiac surgery)
• Coupled with exercise stress echocardiography, is able to
accurately assess global cardiovascular function, specifically
in patients with LV dysfunction
Demers et al, Am Heart J 2001
Picano et al, Heart 2013
Rostagno et al, Intern Emerg Med 2008

7. Aim of the Study
Long-term global cardiovascular performance
assessed by ESE and 6-MWT, in patients with
ischaemic mitral regurgitation referred to valve
replacement with Bio prostheses, compared to
replacement with Mech prostheses.

8. .
Preoperative Data
M: mechanical prostheses; B: biological prostheses; BSA: body surface area;
VC: vena contracta; 6-MWT: six-minute walking test

9. Operative Data
M: mechanical prostheses, B: biological prostheses; CPB: cardio pulmonary by-pass; ACC: aortic cross
clamp; CABG: coronary artery by-pass grafting; IABP: intraortic ballon pump
*P values refer to differences among Mech and Bio groups

10. Resting and Exercise Follow-up Echocardiographic data
32±13 months
M: mechanical prostheses, B: biological prostheses; CO: cardiac output; CI: cardiac index; MPG: mitral
peak gradient; MMG: mitral mean gradient; SPAP: systolic pulmonary arterial pressure
*p<0.05 (Rest vs. Exercise); † p<0.05 (M vs. B)

11. Change in 6-MWD
Bio Mech
Bio Mech
Absolute difference (mt)
Relative change (%)
32±13 months
P<0.0001 P<0.0001

12. Postoperative change 6-MWT distance
20 30 40 50 60 70 80
250
200
150
100
50
0
-50
-100
-150
-200
-250
Post-op changes in 6MWT distance
r=-0.70
p<0.0001
 Biological
 Mechanical
Exercise SPAP, mmHg

13. Independent Determinants of 6-MWD
IEOA: indexed effective orifice area; SPAP:systolic pulmonary arterial
pressure; 6-MWD: six-minute walking distance

14. Limitations
 Retrospective study
 The prosthesis choice for individual patients may have
been subjected to selection bias
 Limited informations regarding preoperative myocardial
viability in the two groups
 No comparison group with newer ring and subvalvular
procedures

15. CONCLUSIONS
 Our findings suggest that use of mechanical prosthesis
in patients with severe ischemic MR is not inferior to
bioprostheses.
 In the long term, patients with mechanical prostheses
seem to show a better cardiovascular performance
compared to patients with biological prostheses
 These observations warrant future bigger confirmatory
studies with a longer follow-up

16. Thank you very much
There’s plenty of room at the bottom
Richard Feynman
1918-1988