Parachute tricuspid valve: a systematic review

BACKGROUND: A parachute tricuspid valve is a very rare congenital cardiac anomaly. Its morphological features and clinical implications have not been sufficiently described so far. The purpose of the present systematic review is to disclose the morphological and clinical characteristics of parachute tricuspid valve, and to discuss its diagnostic methods, treatments and patients’ outcomes. MAIN BODY: The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement guidelines were followed in this systematic review. Publications were systematically searched in the PubMed, Highwire Press, and the Cochrane Library databases. By comprehensive retrieval of the pertinent literature published between 1979 and 2019, 13 reports were collected with 14 patients recruited into this study. Their ages ranged from neonate to 52 years old with a median age of 23 years. Tricuspid valve regurgitation of a less-than-severe degree was seen in 6 (60%) patients, tricuspid valve stenosis was present in 3 (30%) patients and normally functioning tricuspid valve was noted in 1 (10%) patient. All patients had a single papillary muscle in the right ventricle. The chordae tendineae could be normal in length and thickness, or elongated, or shortened and thickened. Forty percent of the patients were asymptomatic or with only mild symptoms and did not need a surgical or interventional therapy, and 6 (60%) patients were indicated for a surgical/interventional treatment due to their severe presenting symptoms, associated congenital heart defects, and the resultant severe right ventricular inflow obstruction and (or) tricuspid stenosis. Patients’ outcomes varied depending on the substantial status of the patients with a survival rate of 70% and mortality rate of 30%. CONCLUSION: A few patients with a parachute tricuspid valve are asymptomatic or only with mild symptoms and a surgical or interventional treatment is not required. The surgical/interventional indications for parachute tricuspid valve patients are their severe presenting symptoms, associated congenital heart defects, and the resultant severe right ventricular inflow obstruction and (or) tricuspid stenosis. The survival rate of this patient setting is satisfactory.