Left Atrial Reservoir Function in Symptomatic Versus Asymptomatic Patients with Moderate Mitral Stenosis

BACKGROUND AND AIM OF THE STUDY: Deformation of the left atrium during the reservoir phase may provide information regarding potential preclinical heart disease, but at present insufficient data are available concerning left atrial (LA) reservoir function in valvular heart disease. The study aim was to assess LA reservoir function in patients with moderate mitral stenosis (MS), and its relation to the patient’s clinical status. METHODS: A total of 40 patients (31 females, nine males; mean age 29.47 ± 19.1 years) with isolated moderate MS and in sinus rhythm were allocated to either symptomatic or asymptomatic groups (n = 20 in each group). All patients provided their complete medical history, were examined clinically and underwent transthoracic echocardiography to assess MS severity, systolic pulmonary artery pressure (SPAP), mean pulmonary artery pressure (MPAP), left atrial maximal volume (LAV(max)), left atrial minimal volume (LAV(min)), and indices of left atrial reservoir function, including total left atrial emptying volume Tot(empVol), indexed Tot(empVol), and total left atrial emptying fraction (LAEF). RESULTS: Symptomatic patients showed a significantly higher mean LAV(max) (79.25 ± 19.12 versus 70.65 ± 13.34 ml, p = 0.022), LAV(min) (54.63 ± 6.68 versus 47.1 ± 12.87 ml, p = 0.029), Tot(empVol) (23.83 ± 5.33 versus 18.4 ± 7.13 ml, p = 0.01), indexed Tot(empVol) (14.73 ± 2.49 versus 12.53 ± 3.18 ml/m2, p = 0.02), SPAP (44.35 ± 7.79 versus 32.65 ± 10.6 mmHg, p = 0.002), and MPAP (37.60 ± 10.78 versus 30.46 ± 7.55 mmHg, p = 0.02) and a significantly lower mean LAEF (30.40 ± 7.26 versus 36.13 ± 6.37%, p = 0.011). Significant negative correlations were noted between LAEF with SPAP, LAV(max) and LAV(min). Further significant associations were detected for the symptomatic group between LAEF (r = -0.43) and mitral valve area (r = -0.37). Similarly, multivariate linear regression analysis revealed a significant negative association between presence in the symptomatic group and LAEF (β = -4.78, SE = 2.22, p <0.05). Finally, Tot(empVol) was the strongest predictor of LAEF (β = 1.23). CONCLUSION: LA reservoir function is impaired in symptomatic patients with moderate MS.