Carlo Fino MDCarlo Fino MDCardiovascular Department

Azienda Ospedaliera Papa Giovanni XXIIIBergamo, Italy

Mechanical versus Biological Prostheses for Chronic Ischaemic Mitral Regurgitation: A Long-Term Hemodynamic and Functional Capacity

Comparison

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 2009Lorusso et al JTCVS 2013

COR: Class of Recommendation LOE: level of Evidence

Summary of Recommendations for Chronic Severe Ischemic MR

AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease, JACC 2014

…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

Complete chordal-sparing mitral valve replacement

Pibarot P et al, Heart 2006

•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

Cardiovascular Assessment

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.

.

Preoperative Data

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

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

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)

Change in 6-MWD

MechBioBio Mech

Absolute difference (mt)

Relative change (%)

P<0.0001P<0.0001

32±13 months

20 30 40 50 60 70 80-250

-200

-150

-100

-50

0

50

100

150

200

250P

ost

-op

ch

an

ges

in 6

MW

T d

ista

nc

e

r=-0.70p<0.0001

Biological Mechanical

Exercise SPAP, mmHg

Postoperative change 6-MWT distance

Independent Determinants of 6-MWD

IEOA: indexed effective orifice area; SPAP:systolic pulmonary arterial pressure; 6-MWD: six-minute walking distance

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

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

There’s plenty of room at the bottom Richard Feynman

1918-1988

Thank you very much