However, Heresi et al. used a sensitive assay to measure cardiac troponin I (cTnI), a myocardial infarction biomarker, and found a significant positive association between cTnI and a more severe PAH and worse clinical outcomes in patients with PAH [60], suggesting that the susceptibility of the RV to ischemic events is not completely understood. This evidence concerns the gene TNNI3 and myocardial infarction.