Cardiac involvement in mixed connective tissue disease: a systematic review.

OBJECTIVE: To report the clinical characteristic of cardiac disease in patients with mixed connective tissue disease (MCTD).

METHOD: We identified published case series that reported cardiac manifestations of patients with MCTD by searching the PubMed database using the search terms "mixed connective tissue disease". We identified 11 case series that met our eligibility criteria.

RESULT: 616 patients were included. Prevalence of cardiac involvement varied from 13% to 65% depending on patient selection and method used for detection. Pericarditis was the most common cardiac diagnosis with a prevalence of 30% and 43% in two prospective studies. Non-invasive cardiac tests, including electrocardiogram and echocardiogram, detected subclinical cardiac abnormalities in 6%-38% of patients. These abnormalities included conduction abnormalities, pericardial effusion and mitral valve prolapse. Diastolic dysfunction and accelerated atherosclerosis were well-documented in a case-control study. Three prospective studies revealed an overall mortality of 10.4% over the period of follow-up of 13-15 years. 20% of the mortality was directly attributable to cardiac cause.

CONCLUSION: Cardiac involvement was common among patients with MCTD though the involvement was often clinically inapparent. Non-invasive cardiac tests might have a role for subclinical disease screening for early diagnosis and timely treatment as cardiac involvement was one of the leading causes of mortality.