Right ventricular functional recovery after acute myocardial infarction: relation with left ventricular function and interventricular septum motion. GISSI-3 echo substudy

Objective: To evaluate the pattern of right ventricular ( RV) functional recovery and its relation with left ventricular (LV) function and interventricular septal (IVS) motion in low risk patients after acute myocardial infarction ( AMI). Design and setting: Multicentre clinical trial carried out in 47 Italian coronary care units. Patients: 500 patients from the GISSI ( Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico) - 3 echo substudy, who underwent serial echocardiograms 24 - 48 hours after symptom onset and at discharge, six weeks, and six months after AMI. Results: Tricuspid annular plane systolic excursion (TAPSE) increased significantly during follow up ( mean (SD) 1.79 ( 0.46) cm at 24 - 48 hours to 1.92 ( 0.46) cm at six months, p< 0.001) and the increase was already significant at discharge ( 1.88 ( 0.47) cm, p< 0.001). LV ejection fraction ( LVEF) was the best correlate of TAPSE at 24 - 48 hours ( r = 0.15, p = 0.001). TAPSE increased significantly in patients both with reduced (,<45%) and with preserved (> 45%) LVEF, but the magnitude of increase was higher in patients with lower initial LVEF ( p = 0.001). Improvement in IVS wall motion score index ( IVS-WMSI) was the only independent predictor of TAPSE changes during follow up ( r = 20.12, p = 0.007). Conclusions: In low risk patients after AMI, RV function recovered throughout six months of follow up and was already significant at discharge. TAPSE was significantly related to LVEF at 24 - 48 hours. The magnitude of RV functional recovery was higher in patients with lower initial LVEF. RV functional recovery is best related to IVS-WMSI improvement, suggesting that IVS motion has an important role in RV functional improvement in this setting.