(P263) THE EFFECTS OF MITRAL ANNULAR CALCIFICATION ON LONG-TERM OUTCOMES AFTER MITRAL VALVE REPLACEMENT IN SEX AND AGE MATCHED PATIENTS

Background: Mitral annular calcification (MAC) portends a technically challenging mitral valve surgery and has been associated with worse short-term outcomes and long-term survival after mitral valve replacement (MVR) than other mitral etiologies. MAC patients requiring MVR are often older and more comorbid than patients without MAC, further compounding the risk of adverse outcomes. However, there is no study that compares long-term outcomes between patients with and without MAC in age- and sex-matched cohorts.

METHODS AND RESULTS: Between 2000-2017, 67 patients with MAC underwent MVR, who were age and sex propensity matched 1:3 with other mitral etiologies (degenerative, rheumatic, ischemic and isolated dilatational) without MAC to create a study cohort of 268 patients. An extended Cox regression model with time-dependent covariate included was used to investigate the long-term outcomes of MAC compared to other etiologies.

The groups were matched for age (MAC 70.5 years, non-MAC 70.4 years) and sex (MAC 61.2% male, non-MAC 61.7% male). Significantly higher rates of COPD (41.8% vs. 25.4%, p=0.013), diabetes (38.8% vs. 15.9%, p< 0.001), chronic renal failure (23.9% vs. 7%, p< 0.001), dialysis (10.4% vs. 3%, p=0.022), and family history of CAD (44.8% vs. 19.9%, p< 0.001) were observed in the MAC group compared to the non-MAC group. Post-operative complications between the two groups were similar besides a significantly higher incidence of acute renal failure requiring dialysis in the MAC group (29.9% vs. 6.5, p< 0.001). MAC was not a risk factor for one-year mortality (Odds Ratio 0.412, 95% confidence interval [CI]: 0.136-1.245, p=0.12). After one year, MAC was an independent risk factor for reduced survival (Hazard Ratio 2.781, 95% CI 1.642-4.709, p< 0.001) (Figure 1). The 5-year and 10-year survivals were significantly lower in the MAC group than in the non-MAC group (5-year: 51.0 ± 6.9% vs. 74.6 ± 3.1%; and 10-year: 40.1 ± 8.0% vs. 51.8 ± 4.1%).

Conclusion: In this age- and sex-matched cohort, patients with MAC exhibited more comorbidities but demonstrated similar early outcomes following MVR compared to those without MAC. However, patients with MAC have worse long-term survival following MVR versus those without MAC. MAC is an independent risk factor for reduced long-term survival following MVR, highlighting the notion that MVR does not address the underlying pathophysiology of disease progression in MAC.