Risk Factors for Early Bioprosthetic Heart Valve Degeneration in Patients with Rheumatic Fever

Abstract

Background: Rheumatic Fever (RF) is an immunological disorder related to exposure to group a streptococcus and rheumatic heart disease is an important cause of valve replacement. Bioprosthetic valves tend to degenerate faster in rheumatic patients, presumably due to immune mechanisms. Objectives: The study sought to assess whether classic risk factors for cardiovascular disease are related to Early Valve Degeneration (EVD) in patients with RF. Design: Case-control study. Methods: Patients with RF and EVD or Late Valve Degeneration (LVD) were selected. The cutoff point was 9 years for a second valve surgery. Data regarding cardiovascular risk of the two groups were obtained and compared. A data imputation analysis was used to deal with missing data. Results: Twenty valves were included in the primary outcome analysis and 33 were used for data imputation. The mean age for the first valve replacement was 40.6 (±6.2) years for the EVD group and 31.1 (±12.3) years for the LVD group, (p = 0.03), which remained significant after data imputation. For blood pressure, there was a non-statistically significant trend towards higher diastolic pressure in patients with EVD in relation to LVD (86.8 (±7.2) and 79 (±10.9) mmHg, respectively, p = 0.08), which after data imputation was statistically higher than that of the LVD group (88 [85.4-88.8] and 77 [73-84.5] mmHg, respectively, p = 0.001). Lipid profile was also worse on the EVD group. Conclusions: The data suggest that EVD may result more from aging and cardiovascular factors than from immunological mechanisms, suggesting stricter targets for cardiovascular disease in these patients.