The effective treatment for most patients with secundum atrial septal defect (ASD) is Transcatheter closure procedure. Immediately after closure, right ventricular (RV) volume overload improves and there is also subsequent marked improvement in left ventricular (LV) stroke volume. It has been reported, that LV filling pressure (LVFP) increases after ASD device closure in some patients.
The determinants of LVFP elevation after transcatheter ASD closure have not been fully investigated. So, this study analysed the time course of LVFP after transcatheter ASD closure on Doppler echocardiography to determine the predictors of subsequent LVFP elevation.
The study involved 97 adult patients with sinus rhythm who underwent both transcatheter ASD closure and transthoracic echocardiography. Elevated LVFP was diagnosed during the first month of follow-up according to the American Society of Echocardiography guidelines: that is, ratio of transmitral early filling to the lateral annular diastolic velocity (lateral E/e’) >13 was used to exclude the effect of the device on the atrial septum.
Out of the 97 adult patients with sinus rhythm who underwent both transcatheter ASD closure and transthoracic echocardiography, fifteen patients (15.5%) were diagnosed with increased LVFP during the 1-month follow-up period (median lateral E/e’: from 9.2, IQR, 6.6–10.8; to 15.5, IQR, 13.8–17.8; P<0.001). Independent predictors of LVFP elevation were left ventricular (LV) relative wall thickness, lateral E/e›, and peak tricuspid regurgitation pressure gradient (TRPG) at baseline (OR, 1.67; 95% CI: 1.04–2.69; OR, 1.52; 95% CI: 1.07–2.15; and OR, 1.14; 95% CI: 1.04–1.25; cut-offs: 0.42, 7.5, and 27.0 mmHg, respectively).
Median lateral E/e› returned to baseline in most patients with LVFP elevation during 6 months of subsequent follow-up (1-month–6-month follow-up: 15.5, IQR, 13.8–17.8; 11.1, IQR, 8.8–14.8, respectively; P=0.001).
Remodelling of both ventricles started immediately after ASD closure, and gradual changes continued through 6 months of follow-up, but no significant changes were observed between the 1-month and 6-month follow-up time points.
On comparison of echocardiography parameters, however, RWT was significantly greater in patients with LVFP elevation. The severity of TR significantly improved 1 month after the procedure in patients without LVFP elevation, but showed no marked change in patients with LVFP elevation. The severity of MR did not change significantly during the 1-month follow-up period in either group.
Left-to-right inter-atrial shunting causes LV under-filling as a counterbalance to RV over-filling, which can prevent congestive heart failure due to intrinsic LV dysfunction by decreasing preload. The unmasking of this issue by ASD closure is generally considered to be the primary etiology of LVFP elevation following this procedure.
Increased LVFP was estimated on Doppler echocardiography after transcatheter ASD closure and was associated with LV wall thickening, impaired LV diastolic function, and increased peak TRPG. LVFP, however, decreased to the normal range by 6 months after closure in most patients.