Prognostic value of right ventricular diastolic dysfunction in patients with inferior ST-elevated myocardial infarction

Abstract

Background: Right ventricle infarction (RVI) is predominantly a complication of inferior wall myocardial infarction; it occurs in approximately one third of these patients. Right ventricular dysfunction in patients with inferior STEMI and RV infarction was under assessed. Nevertheless, studies which targeted RV assessment by echocardiography, did not routinely evaluate RV diastolic dysfunction. In this study, we aimed to evaluate RV diastolic dysfunction and its prognostic value in patients with inferior STEMI and RVI.

Results: Sixty patients with inferior STEMI and RV infarction, who underwent primary PCI were enrolled in the study. Patients with pre-existing clinical conditions that might affect RV function, were excluded. Echocardiography was performed within twenty-four hours following the PCI, to assess the RV systolic and diastolic functions with special focus on tricuspid inflow velocities (E velocity, A velocity and E/A ratio) by pulsed wave (PW) doppler and tricuspid annular velocities by tissue doppler index (TDI) (E', A' and E/E' ratio). Clinical features and MACE, including cardiogenic shock, arrhythmia, stroke, reinfarction and death were analyzed in all our patients within 3 months follow up period. The average age of the study population was 51.58 ± 10.11 years, 10% were females. Five patients developed MACE (death, cardiogenic shock and pulmonary edema, anterior STEMI and cardiogenic shock, recurrent inferior STEMI, and arrhythmia and stroke), of whom four occurred in hospital within the first 48 h. Patients who developed MACE had high filling pressures, as all of them had E/E' > 6. E' velocity ≤ 6 cm/sec was associated with increased MACE as 25% of patients with E' velocity ≤ 6 had MACE compared with 2.3% of patients with E' velocity > 6 with a p value of 0.015.

Conclusions: Tricuspid annular velocities by TDI are essential when evaluating RV diastolic dysfunction. E/E' and E' velocity have a prognostic value in patients with inferior STEMI and RV infarction; E/E' > 6 and E' velocity ≤ 6 cm/sec were associated more MACE in patients with inferior STEMI and RVI.

Keywords: Diastolic dysfunction; Right ventricle infarction; ST elevation myocardial infarction; Tissue Doppler imaging.