Jeff Macemon MBChB, PDMSM Advanced Trainee, CTS Two-Year Outcomes of Surgical Treatment of Moderate Ischaemic Mitral Regurgitation Jeff Macemon MBChB, PDMSM Advanced Trainee, CTS

BACKGROUND

A patient who is undergoing CABG had Moderate Ischaemic Mitral Regurgitation. Should repair or replacement of the Mitral Valve be performed? No Repair Replacement

Background ~10% of patient develop Mitral Regurgitation following MI Caused by Papillary muscle displacement Leaflet tethering Reduced closing forces Annular dilatation MR had an adverse effect on heart failure Available evidence for Severe MR supports surgical management at the time of CABG Management of Moderate iMR remains controversal

Background Some experts advocate revascularisation alone Others support restrictive annuloplasty The addition of Mitral surgery at the time of CABG necessitates Opening of the heart Longer CPB Leading to increased perioperative risk

Background Cardiothoracic Surgical Trials Network CABG alone vs CABG + MV repair At 1 year there was no significant difference in LV reverse remodelling or MACCE Combined procedure significantly reduced prevalence of moderate or severe MR at the expense of higher postoperative AV arrhythmias and serious neurological events The current study reports the 2 year outcomes for the same cohort

Hypothesis MV repair at time of CABG: Positive influence on reverse ventricular remodelling i.e. reduces LVESVI And hence improvement on MACCE and survival

Patient cohort 26 centres Adults with moderate iMR and multivessel CAD undergoing CABG Patients with structural MR excluded Verified by independent lab Approved rigid or semirigid annuloplasty ring to downsize the MV annulus CPB supported CABG

Trial end points Primary: Secondary endpoints Degree of left ventricular reverse remodelling As measured by LVESVI Secondary endpoints Findings on TTE MACCE (composite of death/stroke/subsequent MV surgery/hospitalisation for heart failure/worsening NYHA class/worsening MR/worsening quality of life/re hospitalisation.

LV regional wall motion Motion at each of the 17 segments was assessed at 6, 12, and 24 months

Results 301 patients (151 CABG vs 150 CABG/MVR) Similar baseline characteristics “Concomitant procedures were performed in 19%” In CABG/MVR group average MVA 31.4+/- 5.0mm 93% patients received ring of 30mm or less

Results X-clamp time 8 CABG patients underwent combined procedure 74.7 +/- 36.7 min vs 106.8 +/- 49.7 min (P<0.001) 8 CABG patients underwent combined procedure 3 MVR/CABG patients underwent CABG alone 2 patients in CABG alone underwent redo for MVR

Results At 2 years LVESVI Mod or severe MR 42.2 +/- 20.0ml vs 43.2 +/- 20.6ml (P=0.71) Mod or severe MR 11.2% vs 32.3% (P<0.001)

Results MACCE Quality of life No difference at 2 years Quality of life No difference Combined procedure group had higher DASI (cardiac physical function) scores P=0.02

Conclusion Findings imply that patient enrolled in this trial had iMR caused by reversible ischaemia rather than nonviable scar formation Addition of MV repair to CABG had no incremental effect on LV remodelling at 2 years Patients who underwent CABG alone had higher postop mod/severe MR but did not translate into MACCE Addition of MVR associated with longer cross clamp and bypass times, longer post op length of stay and higher serious neurological and SVA events

Strengths of the study Good follow on from original design 100% patient follow up

Limitations of the study Self reported Primary end point was echo finding, not MACCE Did not specify preop evaluation of myocardial viability Short observation period

CABG or MVR/CABG??