Heart valve operations associated with reduced risk of death from mitral valve disease but other operations associated with increased risk of death: a national population-based case–control study

BACKGROUND: Mitral valve disease is the most common heart valve disease worldwide. Heart valve operation is the predominant treatment strategy for heart valve disease. This study analyzed the death risk from heart valve disease with respect to the frequency of heart valve operation and other operations in patients with mitral valve disease. MATERIALS AND METHODS: We conducted a retrospective nationwide population-based case–control study using a claims dataset from Taiwan’s National Health Insurance Research Database. The case and control groups enrolled mitral valve disease patients from 2002 to 2013 who had either underwent an heart valve operation procedure or not, respectively. Conditional logistic regression was estimated the odds ratios (ORs) associated with various risk factors for heart valve operation-related death, including other operations and comorbidities. RESULTS: A total of 25,964 patients with mitral valve disease were recruited for the study and divided into heart valve operation (600 patients) and non-heart valve operation (25,364 patients) groups. After matching, a total of 1800 non-heart valve operation patients were selected for final analysis. Heart valve operation was associated with decreased risk of death (adjusted OR [aOR] 0.439), but operations related to other cardiovascular disease (CVD, aOR 3.691), respiratory conditions (aOR 3.210), and the urinary system (aOR 1.925) were associated with increased risk of death for patients with mitral valve disease. Patients with mitral valve disease and diabetes (aOR 1.505), chronic kidney disease (CKD, aOR 3.760), or emphysema (aOR 2.623) also had a higher risk of death. Patients who underwent more heart valve operations had a lower risk of death from mitral valve disease, but patients who underwent more other operations had a higher risk of death from mitral valve disease. CONCLUSIONS: The death risk for patients with mitral valve disease patients could be lowered by more frequently performing heart valve operations. However, the risk of death is increased for patients with mitral valve disease who more frequently undergo other operations, chiefly those for other CVD system, respiratory conditions, and urinary system, or have comorbidities such as diabetes, chronic kidney disease, and emphysema.