Abstract 2332: Mortality After Mitral Valve Repair/Replacement for Chronic Non-ischemic Regurgitation: Association with Post-Operative Ventricular Tachycardia and Ventricular Dysfunction
Background: Despite excellent early survival after mitral valve replacement/repair (MVR/r) for mitral regurgitation (MR), late death, all cause and sudden (SD), exceeds that expected without MR. We previously reported high prevalence of asymptomatic ventricular tachycardia (AVT = ≥ 3 sequential PVCs) in severe MR and found that AVT usually recurs despite MVR/r. We now aim to define the impact of post-op AVT, with and without subnormal left and/or right ventricular ejection fraction (EF), on survival and SD after MVR/r.
Methods: In 68 prospectively studied pts with MR (53% women, av age 58 [28 –77] yrs) with ≥1 post-op EF assessment and ≥1 post-op 24 hour AECG, the maximum number of post-op VT runs per AECG and the maximum length of any VT run, alone and combined with post-op EF, were related to all cause death or SD late after MVR/r (av follow-up [survivors] = 9.2 ± 4.3 years) Kaplan-Meier curves were compared by log rank testing.
Results: Death occurred in 16 patients (8=sudden, 5 other cardiovascular (CV), 2 non-CV, 1 unknown). Average annual risk (AAR) of death was higher in the tercile with > 1 AVT run on any post-op AECG than in other pts (4.6% vs. 1.4 %, p<.03). Subnormal EF alone was less strongly associated with death (AAR 3.7% vs. 1.8%, p<.10), but AAR was highest in pts with both subnormal EF and > 1 run of AVT/24 ECG (5.6% vs. 1.7%, p<.01). SD also was best associated with frequent VT plus subnormal EF (AAR 3.5% vs. 0.6%, p<.01); SD association was weaker for VT alone (AAR 2.5% vs. 0.5%, p<.06) or subnormal EF alone (AAR 2.2% vs. 0.6%, p<.07). Maximum VT length on any post-op AECG did not relate to death or SD, alone or combined with EF.
Conclusion: After MVR/r, AVT and ventricular dysfunction independently predict death and SD. Pts at highest risk have both descriptors. Thus, intracardiac defibrillators may improve post-op survival in this population.