Journal Club Articles

Here is a nice general overview of the topic if you're interested in reading before you get to the individual studies. 

http://circ.ahajournals.org/content/123/16/1788.full

Articles:

http://www.nejm.org/doi/pdf/10.1056/NEJMoa021274

http://journal.publications.chestnet.org/article.aspx?articleid=1090134

Abstract: (article to come in full form from the library) http://www.ncbi.nlm.nih.gov/pubmed/23102885