Clinical and geographic patterns of rheumatic heart disease in outpatients attending cardiology clinic in western Kenya

Abstract

Introduction: Rheumatic heart disease (RHD) remains a leading cause of cardiovascular mortality in sub-Saharan Africa. Identifying high risk populations and geographic patterns of disease is crucial to developing RHD prevention and screening strategies in endemic areas.

Objectives: To identify clinical and geographical trends in RHD throughout western Kenya METHODS: We conducted a retrospective chart review of all patients <50years old attending adult cardiology clinic at a national referral hospital in western Kenya. Demographic information, residential location and cardiac history were collected. We mapped the spatial distribution of cardiac disease rates and analyzed the effect of distance from the hospital on RHD status.

Results: Two-thirds (64%) of cardiology clinic patients <50years old (n=906) had RHD. RHD patients were younger (26 vs. 33years, p<0.001) and more often female (69% vs. 59%, p=0.001) than non-RHD patients. Global clustering of disease rates existed within 200km of the hospital with significant clustering of the RHD and non-RHD rate difference surrounding the hospital (Moran's I: 0.3, p=0.001). There was an interaction between ethnicity and distance from the hospital such that the odds of RHD decreased with further distance for Nilotes, but the odds of RHD increased with further distance for non-Nilotes CONCLUSION: Most adult cardiology patients treated at a national referral hospital in western Kenya have RHD. Young people and females are commonly affected. Ethnicity and distance to the hospital interdependently affect the odds of RHD. Future studies in this area should consider the impact of ethnic predisposition to RHD.

Keywords: Africa; Epidemiology; Kenya; RHD; Rheumatic heart disease; Valvular disease.