Surgical and transcatheter pulmonary valve replacement in patients with repaired tetralogy of Fallot: cardiac magnetic resonance imaging characteristics and morphology of right ventricular outflow tract

BACKGROUND

Pulmonary valve replacement is recommended in patients with repaired tetralogy of Fallot based on cardiac magnetic resonance imaging (MRI) criteria. This procedure is performed by surgical or transcatheter approaches.

OBJECTIVE

We aimed to investigate the differences in preprocedural MRI characteristics (volume, function, strain) and morphology of the right ventricular outflow tract and branch pulmonary arteries in patients for whom surgical or transcatheter pulmonary valve replacement was planned.

MATERIALS AND METHODS

Cardiac MRI of 166 patients with tetralogy of Fallot were analyzed. Of these, 36 patients for whom pulmonary valve replacement was planned were included. Magnetic resonance imaging characteristics, right ventricular outflow tract morphology, branch pulmonary artery flow distribution and diameter were compared between surgical and transcatheter groups. Spearman correlation and Kruskal-Wallis tests were performed.

RESULTS

Circumferential and radial MRI strain for the right ventricle were lower in the surgical group (P=0.045 and P=0.046, respectively). The diameter of the left pulmonary artery was significantly lower (P=0.021) and branch pulmonary artery flow and diameter ratio were higher (P=0.044 and P = 0.002, respectively) in the transcatheter group. There was a significant correlation between right ventricular outflow tract morphology and right ventricular end-diastolic volume index and global circumferential and radial MRI strain (P=0.046, P=0.046 and P= 0.049, respectively).

CONCLUSION

Preprocedural MRI strain, right-to-left pulmonary artery flow, diameter ratio and morphological features of the right ventricular outflow tract were significantly different between the two groups. A transcatheter approach may be recommended for patients with branch pulmonary artery stenosis, since both pulmonary valve replacement and branch pulmonary artery stenting can be performed in the same session.

High AST/ALT Ratio Is Associated with Cardiac Involvement in Acute COVID-19 Patients

Background and Objectives: We aimed to assess the effect of AST/ALT ratio on echocardiographic and cardiac magnetic resonance imaging (CMRI) parameters after COVID-19 patients recover. Materials and Methods: 87 patients with COVID-19 were included in the study. The patients were hospitalized with COVID-19 pneumonia, but the patients did not need intensive care unit follow-up or non-invasive mechanical ventilation support. After a discharge and two weeks following the positive swab test result, patients were considered eligible if they had any symptoms. Transthoracic echocardiography (TTE) was performed within 24 h prior to CMRI. The median value of AST/ALT ratio was found, and the study population was divided into two subgroups based on the median AST/ALT ratio value. The clinical features, blood test, TTE and CMRI results were compared between subgroups. Results: C-reactive protein, D-dimer and fibrinogen were found to be significantly higher in patients with high AST/ALT ratio. LVEF, TAPSE, S', and FAC were significantly lower in patients with high AST/ALT ratio. LV-GLS were significantly lower in patients with high AST/ALT ratio. In CMRI, native T1 mapping signal, native T2 mapping signal and extracellular volume raised significantly in patients with high AST/ALT ratio. Right ventricle stroke volume and right ventricle ejection fraction were significantly lower in patients with high AST/ALT ratio, but right ventricle end systolic volume was significantly higher in patients with high AST/ALT ratio. Conclusion: High AST/ALT ratio is related to impaired right ventricular function parameters with CMRI and echocardiography after recovery from acute COVID-19. Assessment of AST/ALT ratio at hospital admission may be used to assess the risk of cardiac involvement in COVID-19 disease, and these patients may require closer follow-up during and after the course of COVID-19.

Cardiac magnetic resonance T2* mapping in patients with COVID-19 pneumonia is associated with serum ferritin level?

The coronavirus disease of 2019 (COVID-19)-related myocardial injury is an increasingly recognized complication and cardiac magnetic resonance imaging (MRI) has become the most commonly used non-invasive imaging technique for myocardial involvement. This study aims to assess myocardial structure by T2*-mapping which is a non-invasive gold-standard imaging tool for the assessment of cardiac iron deposition in patients with COVID-19 pneumonia without significant cardiac symptoms. Twenty-five patients with COVID-19 pneumonia and 20 healthy subjects were prospectively enrolled.Cardiac volume and function parameters, myocardial native-T1, and T2*-mapping were measured. The association of serum ferritin level and myocardial mapping was analyzed. There was no difference in terms of cardiac volume and function parameters. The T2*-mapping values were lower in patients with COVID-19 compared to controls (35.37 [IQR 31.67-41.20] ms vs. 43.98 [IQR 41.97-46.88] ms; p < 0.0001), while no significant difference was found in terms of native-T1 mapping value(p = 0.701). There was a positive correlation with T2*mapping and native-T1 mapping values (r = 0.522, p = 0.007) and negative correlation with serum ferritin values (r = - 0.653, p = 0.000), while no correlation between cardiac native-T1 mapping and serum ferritin level. Negative correlation between serum ferritin level and T2*-mapping values in COVID-19 patients may provide a non-contrast-enhanced alternative to assess tissue structural changes in patients with COVID-19. T2*-mapping may provide a non-contrast-enhanced alternative to assess tissue alterations in patients with COVID-19. Adding T2*-mapping cardiac MRI in patients with myocardial pathologies would improve the revealing of underlying mechanisms. Further in vivo and ex vivo animal or human studies designed with larger patient cohorts should be planned.