Prevalence and Predictors of Left Atrial Appendage Inactivity in
patients of Rheumatic Mitral Stenosis in Sinus Rhythm- An observational
study.
Abstract
BACKGROUND: Systemic thromboembolism is a known complication of
rheumatic mitral stenosis (RMS) in sinus rhythm (SR). Left atrial
appendage (LAA), the commonest site of thrombus formation is usually
hypocontractile (inactive) in such patients. We aimed to study the
prevalence of LAA inactivity (LAAI) in severe RMS and assess its
independent predictors. METHODS: The study population consisted of 100
patients of severe RMS in sinus rhythm. Transthoracic and
transesophageal echocardiography were done to assess LAA contractile
function. Patients with LAA-peak emptying velocity <25 cm/sec
were defined as having LAAI. RESULTS: The mean age of study subjects was
31.66±8.69 years and 56% were females. 73% patients had LAAI (Group
A), while remaining 27% had normal LAA function (Group B). Mitral-valve
area (MVA) and lateral annulus systolic velocity (Sa-wave) were
significantly lower while mean pressure gradient across mitral valve
(MGMV) and serum fibrinogen were significantly higher (all p-values
<0.001) in group A patients. On multivariate regression
analysis, MGMV (p<0.001), Sa-wave (p=0.02) and serum
fibrinogen (p=0.005) were independent predictors of LAAI. Optimal
cut-off values of MGMV, Sa-wave and serum fibrinogen for predicting LAAI
were 11.5mmHg, 6.8cm/sec and 300mg/dL respectively.67(90.55%) patients
in group A compared to 13(48.1%) in group B had LA/LAA smoke. LAAI was
the only independent predictor of left atrium (LA)/LAA smoke and
associated thrombus. CONCLUSION: There is high prevalence of LAAI in
patients of severe MS in SR. MGMV, Sa-wave and serum fibrinogen levels
are independent predictors of LAAI. LAAI is an independent predictor of
LA/LAA smoke and associated thrombus.