Geographic variation in procedure selection and hospital mortality in mitral valve surgery

There is paucity of data relating to the geographic variation in mitral valve (MV) repair trends and outcomes of patients undergoing MV surgery.

Using the 2005-2008 Nationwide Inpatient Sample (NIS) Database, the four geographic regions of the US (Northeast, Midwest, South, and West) were compared with respect to baseline characteristics, mitral procedure selection, and hospital mortality of patients undergoing either MV repair (ICD-9CM code 35.12) or replacement (ICD-9-CM codes 35.23 and 35.24).

Patient age was similar across regions. The Midwest had the highest proportion of whites, while patients in the South were the least affluent. The Northeast had the highest proportion of patients presenting non-electively. The West and Midwest had more women and patients with private insurance compared to the South, but the proportion of patients on Medicaid was similar across all regions. The Northeast and the South had a higher Charlson Comorbidity Index compared to the West. The overall repair rate was 47%; the Midwest had the highest rate (50%), and the South the lowest (42%) (p = NS). Following adjustment for baseline characteristics, hospital mortality was similar among regions for patients undergoing MV replacement. For the subset undergoing MV repair, hospital mortality was more than 2.5-fold higher in the South than in the Northeast (OR = 2.88, 95% CI 1.45-5.71).

MV repair is utilized in less than half of all mitral procedures nationwide. Repair rates and hospital mortality are comparable across all four regions in the US. Hospital mortality for isolated MV surgery is low. The higher adjusted mortality for patients undergoing MV repair in the South identifies an important area for future improvement in the care of patients with valvular heart disease.