[Cardiopulmonary exercise capacity increases after interventional ASD-closure].
BACKGROUND
In patients with atrial septal defects of the secundum-type (ASD), exercise tolerance is reduced. Generally, ASD closure is recommended in symptomatic patients and in patients with a relevant left-to-right shunt (Qp/Qs > 1.5). Only few data are available concerning objective parameters of cardiopulmonary exercise capacity. The aim of this study was to evaluate exercise capacity as achieved by ergospirometry in adult patients with an ASD at baseline and in the long-term following transcatheter closure.


RESULTS
Thirty consecutive patients (8 male; mean age 43.4 years; defect size 23.5 mm; pulmonary-to-systemic flow ratio (Qp/Qs) 1.94) performed exercise testing on a supine bicycle ergometer. At baseline, oxygen consumption at maximal exercise (VO(2) peak) was 14.3 ml/min kg, oxygen consumption at the anaerobic threshold (VO(2)-AT) was 11.2 ml/min/kg and maximal achieved workload was 86 Watt. At one and six months after ASD-closure, there was no relevant increase of the VO(2) peak, the VO(2)-AT or the maximal workload. After 12 months, there was a significant increase of the VO(2) peak (15.1 ml/min/kg, p = 0.049), the VO(2)-AT (13 ml/min/kg, p < 0.001) and the maximal workload (99 Watt, p < 0.01). An increase of the oxygen consumption at the anaerobic threshold (Delta VO(2) AT) could be seen in 24 out of 30 patients and was independent of shunt volume (Q(p)/Q(s) < or = 2, 1.95 ml/ min/kg; Q(p)/Q(s) > 2, 2.13 ml/min/ kg; ns), defect size (defect < or = 24 mm, 2.0 ml/min/kg; defect > 24 mm, 1.5 ml/min/kg; ns), age (age < or = 44 years, 1.97 ml/min/kg; age >44 years, 1.66 ml/min/kg; ns), gender (female 1.56 ml/min/ kg; male 1.91 ml/min/kg; ns) and of the existence of a residual shunt. Highly symptomatic patients had a tendency to have greater benefit from ASD-closure as compared to mildly symptomatic patients (NYHA 0/I 1.85 ml/min/kg; NYHA II 1.5 ml/min/ kg; NYHA III 2.7 ml/min/kg; ns). There was no correlation between shunt volume, shunt size, pulmonal arterial pressure and increase of the oxygen consumption at the anaerobic threshold (Delta VO(2) AT).


CONCLUSIONS
There is no relevant improvement in exercise capacity early (1-6 months) after interventional ASD-closure, but late after ASD-closure (12 months) exercise capacity improves significantly. This improvement can be found in almost all patients independent of gender, age, symptoms, shunt volume and defect size.
Weber
M
M
Kerckhoff-Klinik, Abteilung für Kardiologie, Benekestrasse 2-8, 61231 Bad Nauheim, Germany. Michael.Weber@kerckhoff.med.uni-giessen.de
Neumann
T
T
Rau
M
M
Brandt
R
R
Dill
T
T
Maikowski
C
C
Mitrovic
V
V
Hamm
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology; D006328:Cardiac Catheterization; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006344:Heart Septal Defects, Atrial / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology; D011183:Postoperative Complications / Q000175:diagnosis* / Q000503:physiopathology; D019919:Prosthesis Implantation; D013147:Spirometry
D010100:Oxygen