Behavior of right atrial strain in patients with advanced idiopathic pulmonary arterial hypertension after initiation of specific combined therapy

Background

Right atrial (RA) function has emerged as an important determinant of outcome in pulmonary arterial hypertension (PAH). However, studies exploring RA function and assessing its behavior in response to specific PAH combination therapy, independent of RA size in patients with PAH is not adequately investigated.

Purpose

Assess the behavior of strain based measures of RA in response to combined PAH therapy, independent of RA size in patients with PAH.

Methods

RA peak longitudinal strain (PLS) and peak active contraction strain (PACS) were retrospectively assessed in 38 patients with advanced idiopathic pulmonary arterial hypertension (IPAH) who were referred to Aswan heart Centre and not receiving proper GDMT; at baseline and during follow-up after initiation of specific PAH combination therapy in the form of either Sildenafil/Bosentan or Sildenafil/Macitentan.

Results

Most of the patients were females with median (IR) age 34 (27–39) years. All patients presented with dyspnea WHO-FC III. At baseline, all patients were receiving only monotherapy in the form of sildenafil. Median (IR) time to echocardiographic follow-up was 11 (8–18) months. Patients presented with markedly right ventricle (RV) and RA enlargement, depressed RV systolic function, and reduced RA strain parameters compared with values previously reported in healthy controls. Among various baseline associations of the RA PLS, the strongest were with baseline RA area (rho: −0.659; p<0.001) and RVEF by CMR (rho: 0.570; p<0.001). At follow up; RA PLS and PACS significantly increased (16.6 vs 24 and 7.06 vs 11.42, respectively: p<0.001); however, RA area did not show significant decrease. Only RV TDI & FAC showed significant improvement among different RV function parameters measured by echocardiography. During the follow up period, 11 out of 38 patients (28.9%) were hospitalized. RA PLS change was significantly lower in the hospitalized group than the non-hospitalized group (4.40 vs 10.2; p=0.014). RA PLS change was independently associated with hospitalization in the multivariate regression analysis (95% CI: −0.061 to −0.010; p=0.008).

Conclusion

Initiation of specific PAH combination therapy in undertreated patients with IPAH showed improvement in RA strain parameters despite no change in RA area during follow up.

Funding Acknowledgement

Type of funding sources: None.

P2789A new technique to restore shape and pattern of flow in hypoplastic aortic arch

Background

There is no agreement about the best method for correcting hypoplastic aortic arch in infancy. Residual abnormalities in shape can cause late complications.

Patients and methods

We have developed and applied a new method of direct anastomosis of the descending to the ascending aorta to allow for restoration of shape, function and growth. 12 infants undergoing this technique at the age of 61±3months (range 6–28 months) underwent repeat CT 4–15 months after operation.

Pre- and post-operative arch width, height and height to width ratio were recorded for all cases. Computerized shape analysis using an in-house tool (developed in MATLAB) was used for processing the 3D segmented shapes of the aortic arch, and assessing changes in the cross-sectional area at different levels. Computational Fluid Dynamics (CFD) was used to simulate aortic flow propagation and pattern after surgery, using patient specific geometry and flow boundary conditions.

Results

The pre- and post-operative cross-sectional area along the centerline of the aorta and arch was almost normalized, Figure 1.

The pattern of flow during the cardiac cycle with a retrograde helix in the aortic arch, similar to normal, was observed in all cases with peak velocities of 1.1±0.2m/s.

Aortic Shape and flow after surgery

Conclusion

We here describe a new technique, which at least in the short term appears to normalize the size, shape and pattern of flow in the arch. Long term studies are required to establish the value of this technique.