[Transcatheter closure of atrial septal defect using the amplatzer septal occluder--early haemodynamic and exercise capacity changes].

AIM: To evaluate the outcomes of transcatheter closure of secundum atrial septal defect (ASD) using the Amplatzer Septal Occluder (ASO).

METHODS: Between December 2000 and December 2002, 27 adult patients (20 females, 7 males) with a mean age of 41.1 +/- 13.3 (range 18-62) years were enrolled for an attempted ASD closure with a ASO device. All patients had an isolated secundum ASD with a large left-to-right shunt (ratio of pulmonary to systemic blood flow, Qp:Qs > 1.5;1). Transthoracic color Doppler echocardiographic study was performed on all patients before procedure, after 24 hours, and after one six months of follow-up. Symptom-limited treadmill exercise tests with respiratory gas exchange analysis (Bruce protocol) were performed on all patients before procedure, and six months of follow-up.

RESULTS: The ASO device was successfully implanted in all patients, with only 3 patients with a trivial residual shunt. The ASD diameter ranged from 7 to 24 mm. No predictors for a residual shunt were identified. At one month of follow-up transthoracic echocardiography showed that the device was correctly positioned in all cases. Residual trivial shunt in one month follow-up was shaded in 3 patients. Septal motion abnormalities normalized in all patients. The right ventricular and atrium dimensions evaluated by 2D echocardiography decreased in most of the patients after one and six months of follow-up. After 6 months of ASD closure, all the pts showed a significant improvement of VO2max, VEN/VCO2, VO2peak as well as lengthened of time of exercise. The mean increase of VO2max in pts 40 years old or younger was 9.5 +/- 6.4 (4-10.7) ml/kg/min; compared to 3.9 +/- 4.1 (2-8) in older pts (p < 0.003), the mean increase of time of exercise in pts 40 years old or younger was 12.7 +/- 7.0 (7-14) compared to 9.1 +/- 7.0 (4.3-11) in others (p < 0.008).

CONCLUSIONS: Transcatheter closure of secundum ASD using the ASO is a safe and effective procedure, with excellent short-term follow-up results. During six months observation it caused partial normalization parameters of echocardiography. During six months observation it caused significant improvement of exercise capacity in most of the patients. Younger patients (up to 40 years) can benefit more in exercise capacity after ASD closure in comparison to the older group.