Is There a Simple Biomarker For Predicting The Success of Pulmonary Valvuloplasty?

Background
Pulmonary valve stenosis (PS) could be treated by balloon valvuloplasty. The success of valvuloplasty is estimated by reduction of PG. Right ventricular (RV) strain could occur even with non-severe PG. Markers of myocardial damage with increased afterload such as troponin are hypothesized to increase with severe RV strain. We aim to find a laboratory test that determines the success of valvuloplasty and the relief of RV afterload.

Methods
We recruited patients with PS who are amenable for balloon valvuloplasty . Echocardiographic evaluation and hs troponin T analysis were done before valvuloplasty then 2 weeks and 6 months later. Balloon valvuloplasty were done using single balloon technique.

Results
Forty five patients were recruited with mean age 21.3 ± 14.6 year. Mean PG across pulmonary valve before dilatation was 73 ± 17 mmHg. They were all successfully dilated with significant drop of PG. Mean PG post-dilatation was 22±14 mmHg. Troponin T level was initially positive in 32 cases (71.1%) . In the group who had initially positive troponin, there was a significant correlation between PG and troponin level. Two weeks post-dilatation, troponin T was negative in all cases . Six months later, 8 cases had re-elevation of troponin with increased PG in those cases by 17 ± 9 mmHg.

Conclusions:
PS causes pressure overload on RV resulting in myocardial cell damage. This results in troponin release. Assessment of troponin can help in classifying the degree of stenosis . It could be a marker to detect the failure of valvuloplasty. Troponin re-elevation occurs in pulmonary re-stenosis. This objective laboratory marker can be used to assess the need for re-dilatation .