CARDIOVASCULAR JOURNAL OF AFRICA • Volume 34, No 5, November/December 2023 AFRICA 295 it was shown that 30% of cases had mild MS, 32% had moderate MS and 38% had severe MS. Comparison among patients with different grades of MS (mild, moderate and severe) with regard to the demographic data showed statistically significant differences in the gender distribution only (p = 0.002). Concerning echocardiographic findings, statistically significant/ highly significant differences were found in tricuspid regurgitation (TR) grades, and RV and LA measurements (Table 2). MVA showed a statistically highly significant positive correlation with RV and LA function, and a statistically significant/highly significant negative correlation with RV and LA dimensions. Re-analysis of patients with isolated MS revealed the same significant association (Table 3). The ECG findings demonstrated that 47 patients were in sinus rhythm, while the remaining 34 were in AF. There was no statistically significant difference between patients in both categories in the distribution of different grades of MS severity (p = 0.06). Patients in AF had statistically significantly higher LA area and volume, and statistically significantly lower LA function (p = 0.003) (Table 4). Receiver operating characteristic (ROC) curve analysis was performed for assessing LA function in predicting significant MS (moderate and severe MS) in RHD patients. The area under the curve (AUC) was 0.813, and a value of 39.4% was found to be the best cut-off point to predict significant MS among RHD patients, with a sensitivity of 83.93%, specificity of 80% and a statistically highly significant p-value (p < 0.001) (Fig. 1). Table 3. Correlation analysis between MVA and echocardiography parameters Variables MVA r p-value Right ventricle TAPSE (mm) 0.472 0.000 RVD (ml) –0.412 0.000 All study patients (n = 81) LA area LAD (ml) –0.473 < 0.001 LA area S4 (ml) –0.415 < 0.001 LA area S2 (ml) –0.365 < 0.001 AvLS (ml) –0.435 < 0.001 LA area D4 (ml) –0.507 < 0.001 LA area D2 (ml) –0.473 < 0.001 avLD (ml) –0.530 < 0.001 LA volumes LAvolmax (ml) –0.383 < 0.001 LAvolmin (ml) –0.480 < 0.001 LAVImax (ml/m2) –0.421 < 0.001 LAVImin (ml/m2) –0.512 < 0.001 LA function (%) 0.507 < 0.001 Isolated MS patients (n = 33) LA area LAD (ml) –0.479 0.005 LA area S4 (ml) –0.415 0.016 LA area S2 (ml) –0.359 0.04 AvLS (ml) –0.481 0.005 LA area D4(ml) –0.511 0.002 LA area D2 (ml) –0.426 0.013 avLD (ml) –0.545 0.001 LA volume LAvolmax (ml) –0.418 0.047 LAvolmin (ml) –0.507 0.014 LAVImax (ml/m2) –0.410 0.018 LAVImin (ml/m2) –0.506 0.003 LA function (%) 0.560 0.001 TAPSE: tricuspid annular plane systolic excursion, RVD: right ventricular diameter, LAD: left atrial diameter, LAA S4V: left atrial area systolic four shaper view, LAA S2V: left atrial area systolic two shaper view, LAA D4V: left atrial area diastolic four shaper view, LAA D2V: left atrial area diastolic two shaper view, LAvolmax: maximum left atrial volume, LAvolmin: minimum left atrial volume, LA function: left atrial function. AvLS: average length systole, avLD: average length diastole, LAVI: left atrial volume index, r: Spearman’s correlation coefficient. p-values are based on Spearman’s correlation test as appropriate. Statistical significance at p < 0.05 Table 4: Demographic and echocardiographic characteristics of the patients according to the different MS grades Variables Sinus rhythm (n = 47) AF (n = 34) p-valuea MS severity Mild 17 (70.8) 7 (29.2) 0.06 Moderate 17 (65.4) 9 (34.6) Severe 13 (41.9) 18 (58.1) LA area LAD (ml) 49.7 ± 6.83 53.79 ± 8.6 0.026 LA area S4 (ml) 28.12 ± 7.89 32.26 ± 8.41 0.028 LA area S2 (ml) 22.84 ± 6.08 28.43 ± 8.73 0.003 AvLS (ml) 6.16 ± 0.84 6.73 ± 0.98 0.009 LA area D4 (ml) 21.54 ± 7.82 27.02 ± 9.10 0.005 LA area D2 (ml) 17.32 ± 6.23 23.46 ± 8.63 0.001 avLD (ml) 5.55 ± 0.92 6.28 ± 1.09 0.002 LA volumes LAVS (ml) 89.44 ± 34.27 117.43 ± 48.29 0.005 LAVD (ml) 58.53 ± 31.13 88.27 ± 44.35 0.001 LAVImax (ml/m2) 47.9 ± 18.2 63.1 ± 27.96 0.008 LAVImin (ml/m2) 31.3 ± 16.6 47.3 ± 24.8 0.001 LA function 0.37 ± 0.14 0.28 ± 0.16 0.003 AF: atrial fibrillation, MS: mitral stenosis, EF: ejection fraction, IVSd: interventricular septum diameter, LVPWd: left ventricular posterior wall diameter, LVESD: left ventricular end systolic diameter, LVEDD: left ventricular enddiastolic diameter, LVMI: left ventricular mass index, RWT: Relative wall thickness, TAPSE: tricuspid annular plane systolic excursion, RVD: right ventricular diameter, LAD: left atrial diameter, LAA S4V: left atrial area systolic four shaper view, LAA S2V: left atrial area systolic two shaper view, LAA D4V: left atrial area diastolic four shaper view, LAA D2V: left atrial area diastolic two shaper view, LAvolmax: maximum left atrial volume, LAvolmin: minimum left atrial volume, LA function: left atrial function. AvLS: average length systole, avLD: average length diastole, LAVI: left atrial volume index. ap-values are based on the Kruskal–Wallis test. 1 – Specificity (%) 0.0 0.2 0.4 0.6 0.8 1.1 Sensitivity (%) 1.0 0.8 0.6 0.4 0.2 0.0 Fig. 1. ROC curve for analysis of LA function for the prediction of significant MS.
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