Outcomes of cardiac valve replacement for rheumatic heart disease in aboriginal Australians

Abstract

Background: Few studies have looked specifically at the outcomes of cardiac valve replacement for rheumatic heart disease (RHD) in developing or indigenous populations. Aims: To describe outcomes of cardiac valve replacement in patients with rheumatic heart disease living in urban and rural communities in northern Australia. Methods: Retrospective chart review with some prospective follow-up of 81 consecutive patients, predominantly aboriginal, who underwent mitral and/or aortic valve replacement for RHD between 1964 and 1996. Survival analyses were performed using the Kaplan-Meier method, and multivariable analyses using the Cox Proportional Hazards model. Results: Most patients received mechanical prostheses. There was 1 (1.2%) perioperative death. 27/29 late deaths were related to RHD. Actuarial probability estimates for survival at 1, 5 and 10 years were 91%, 79% and 68% and for complication-free survival were 81%, 52% and 44%. Linearised rates (per 100 person-years) were: death, 4.82; all complications, 14.62; emboli, 3.92; bleeding, 2.68; endocarditis, 1.25; reoperation, 0.50; non-structural dysfunction, 2.10. Diminished preoperative left ventricular function was the only variable strongly associated with death (hazard ratio 3.38, 95% CI, 1.01 to 11.28), and this effect was greatest in the first 2 postoperative years. Conclusions: Survival and freedom from complications in this population are less than in similar studies from developing countries. Consideration should be given to operating before the left ventricular function diminishes substantially and to using techniques which obviate the need for anticoagulation.