Impact of type 2 diabetes mellitus in the utilization and in-hospital outcomes of surgical aortic valve replacement in Spain (2001-2015).

BACKGROUND: The aims of this study were to examine trends in the incidence and in-hospital outcomes of SAVR among T2DM patients from 2001 to 2015, to compare clinical variables among T2DM patients and matched non-T2DM patients hospitalized for SAVR and to identify factors associated with in-hospital mortality (IHM) among T2DM patients.

METHODS: We performed a retrospective study using the Spanish National Hospital Discharge Database, 2001-2015. We included patients who had SAVR as the procedure in their discharge report. For each T2DM patient, we selected a sex-, age-, implanted valve type- and year-matched nondiabetic patient.

RESULTS: We identified 78,223 patients who underwent SAVR (23.49% with T2DM). The prevalence of T2DM increased significantly (p < 0.001) from 16.7% in 2001-2003 to 23.5% in 2012-2015. The incidence of SAVR increased significantly from 28.99 cases in 2001 to 65.79 cases in 2015 per 100,000 individuals in the T2DM population. Using Poisson regression models, we found that the incidence of SAVR was 2.60 times higher among patients with T2DM than among those without diabetes (IRR 2.60; 95% CI 2.56-2.65). The incidence of mechanical SAVR among T2DM patients remained stable from 2001 to 2015, and bioprosthetic SAVR rose from 8.29 to 41.74 cases per 100,000 individuals in the T2DM patient population (p < 0.001). We matched 8835 and 9543 patients who underwent mechanical and bioprosthetic SAVR, respectively. IHM decreased over time in T2DM patients and non-T2DM patients (from 8.89% and 7.81% to 3.88% and 5.07%, respectively). IHM was significantly lower in T2DM patients than in nondiabetic subjects who underwent bioprosthetic SAVR (4.77% vs. 6.04%, p < 0.001), with similar results obtained for mechanical valves (7.11% and 7.77%).

CONCLUSIONS: The incidence of SAVR was higher in T2DM patients, and the incidence of bioprosthetic SAVR increased significantly among T2DM subjects. IHM decreased over time, regardless of the existence or absence of T2DM and the valve type. IHM was significantly lower in T2DM patients than in nondiabetic patients who underwent bioprosthetic SAVR.