Population-based assessment of cardiovascular complications of rheumatic heart disease in Fiji: a record-linkage analysis

Abstract

Objective: To determine population-based rates of non-fatal complications of rheumatic heart disease (RHD).

Design: Retrospective cohort study based on multiple sources of routine clinical and administrative data amalgamated by probabilistic record-linkage.

Setting: Fiji, an upper-middle-income country, where most of the population has access to government-funded healthcare services.

Participants: National cohort of 2116 patients with clinically apparent RHD aged 5-69 years during 2008 and 2012.

Primary and secondary outcome measures: The primary outcome was hospitalisation for any of heart failure, atrial fibrillation, ischaemic stroke and infective endocarditis. Secondary outcomes were first hospitalisation for each of the complications individually in the national cohort as well as in hospital (n=1300) and maternity (n=210) subsets. Information on outcomes was obtained from discharge diagnoses coded in the hospital patient information system. Population-based rates were obtained using relative survival methods with census data as the denominator.

Results: Among 2116 patients in the national cohort (median age, 23.3 years; 57.7% women), 546 (25.8%) were hospitalised for an RHD complication, a substantial proportion of all cardiovascular admissions in the country during this period in those aged 0-40 years (heart failure, 210/454, 46.3%; ischaemic stroke 31/134, 23.1%). Absolute numbers of RHD complications peaked during the third decade of life with higher population-based rates in women compared with men (incidence rate ratio 1.4, 95% CI 1.3 to 1.6, p<0.001). Hospitalisation for any RHD complication was associated with substantially increased risk of death (HR 5.4, 95% CI 3.4 to 8.8, p<0.001), especially after the onset of heart failure (HR 6.6, 95% CI 4.8 to 9.1, p<0.001).

Conclusions: Our study defines the burden of RHD-attributable morbidity in the general population of Fiji, potentially reflecting the situation in low-income and middle-income countries worldwide. Hospitalisation for an RHD complication is associated with markedly increased risk of death, re-emphasising the importance of effective early prevention.

Keywords: Heart failure; OBSTETRICS; PAEDIATRICS; PUBLIC HEALTH; Stroke; Valvular heart disease.