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 SR.Transthoracic and transesophageal echocardiography were done to assess LAA contractile function. Patients with LAA-peak emptying velocity < 25 cm/seconds 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 mitral valve mean gradient (MVMG) and serum fibrinogen were significantly higher (all p-values < 0.001) in group A patients. On multivariate binary logistic regression analysis, MVMG (p < 0.001), Sa-wave (p = 0.02), and serum fibrinogen (p = 0.005) were independent predictors of LAAI. Optimal cut-off values of MVMG, Sa-wave and serum fibrinogen for predicting LAAI were 11.5 mm Hg, 6.8 cm/seconds and 300 mg/dl, respectively. Sixty-Seven (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 with or without associated thrombus. Conclusion:There is high prevalence of LAAI in patients of severe MS in SR. MVMG, Sa-wave, and serum fibrinogen levels are independent predictors of LAAI. LAAI is an independent predictor of LA/LAA smoke with or without associated thrombus.

Spontaneous left atrial echo contrast, mitral annular systolic velocity, and left atrial appendage late emptying velocity in predicting improvement of left atrial function after percutaneous balloon mitral valvuloplasty

“…Using the LAAEV as a marker for inactive LAA, our study found that a value of 25 cm/sec was the cut-off point for inactive LAA, which is consistent with Mukhopadhyay et al [29], who studied 100 patients with severe rheumatic mitral stenosis to determine the prevalence of inactive LAA, but this value is higher than Gawako et al who defined the cut-off value of LAAEV to be 20 cm/sec, which could be a factor in predicting inactive LAA. Nonetheless, this difference could be an indicator of a different pathology [30]…”

Assessment of Coagulation Factors in Patients of Severe Rheumatic Mitral Stenosis in Sinus Rhythm With Left Atrial Appendage Inactivity

“…The main effect of transmitral gradient is increased afterload on LA/LAA leading to impairment of its contractility and promoting stasis. In our previous study, 20 we have already shown that mean gradient across MV ≥11 mmHg is an independent predictor of LAA stasis and in both the patient groups it was higher.…”

“…We have also shown that LAA inactivity is the only independent predictor of LASEC, a marker of LA/LAA stasis in this subset of patients. 20…”

“…We have also shown that LAA inactivity is the only independent predictor of LASEC, a marker of LA/LAA stasis in this subset of patients. 20 Thirdly, a large number of small observational studies have also reported a hypercoagulable state in the left atrium of patients of MS in sinus rhythm. 9,12.…”

“…Inactive LAA was defined as late peak LAAEV <25 cm/s. 15,16 As in our previous study, 20 LAAEV was recorded in three consecutive cycles in two views (mid-esophageal short axis view and two chamber view). Only those patients with mean LAAEV values of <25 cm/s in both the views were enrolled for the study.…”