Subclinical carditis in rheumatic fever: a systematic review.

OBJECTIVE: Subclinical carditis (SCC)--pathological valvular regurgitation detected on echocardiography that is not evident clinically--has been reported in acute rheumatic fever (ARF), but its significance is unknown. We aimed to review the existing literature on the prevalence and outcome of SCC in ARF.

METHODS: We conducted a systematic literature review using MEDLINE.

RESULTS: Prevalences of SCC in ARF ranged from 0% (in one study only) to 53% in 23 articles. The weighted pooled prevalence of SCC in ARF was 16.8% (95%CI 11.9 to 21.6). This increased slightly to 18.1% (95%CI 11.1 to 25.2) by analysing only the 10 studies that applied full World Health Organization criteria for SCC diagnosis. The weighted pooled prevalence of persistence or deterioration of SCC 3 to 23 months after ARF diagnosis was 44.7% (95%CI 19.3 to 70.2) from 11 articles.

CONCLUSION: SCC is relatively common in ARF. Although some studies suggest that SCC lesions may persist or deteriorate, the available data are insufficient and of poor quality, so no confident conclusions can be drawn about the prognosis of SCC. Until better studies are conducted, clinicians will have to make management decisions that are not evidence-based. These decisions will have important practical implications for the use of echocardiography acutely and during follow-up, diagnosis of ARF, and duration of secondary prophylaxis in patients with SCC.