Background: The purpose of this study is to identify independent echocardiographic predictors of mitral stenosis (MS)-related death or intervention in infants. Congenital MS is a rare and morphologically heterogeneous lesion with variable prognosis. Among patients diagnosed with MS in early infancy, echocardiographic factors associated with MS-related intervention or death have not been determined.
Methods and results: The clinical and echocardiographic data of patients diagnosed with MS at age <6 months by echocardiography between 1986 and 2004 were reviewed. The primary outcome was a composite end point of either mitral valve (MV) intervention (catheter or surgery) or death related to MS. Multiple variables from the initial echocardiogram were analyzed for association with outcomes. Seventy-one patients (median age at diagnosis 63 days) fulfilled the inclusion criteria. Multivariate analysis identified higher initial MV mean inflow gradient (P = .009) and lower left ventricular (LV) diastolic length Z-score (P = .006) at presentation as predictors of intervention or death. Among patients with an initial MV inflow gradient < 2 mm Hg, none reached an end point, whereas, among patients with an initial mean gradient >/= 5.5 mm Hg, the risk of intervention or death was 85%. Among patients with a gradient > 2 and < 5.5 mm Hg, an end point was reached in 38%, and an LV diastolic length Z-score </= 0 was predictive of outcome (71% vs 17%, P = .005). Mitral valve morphology was not predictive of outcome.
Conclusions: In young infants with congenital MS, higher mean MV inflow gradient and shorter LV length, but not MV morphology, are associated with increased risk of MV intervention or MS-related death.