Angiotensin II receptor blockers in patients with systemic right ventricles.

Nowadays, there are over 25,000 adult patients with a systemic right ventricle due to a congenitally or surgically corrected transposition of the great arteries. This means that the right ventricle is responsible for maintaining the circulation of the body. These patients have an increased risk of various cardiac disorders, causing deterioration of their clinical condition and contributing to their premature deaths. The latter is mainly caused by progressive heart failure of the systemic right ventricle, which is present in 90% of all adults with a systemic right ventricle. It has been demonstrated that the degree of right ventricular dysfunction correlates with myocardial fibrosis and right ventricular hypertrophy.
Angiotensin II receptor blockers (ARB) have a proven beneficial effect in patients with left ventricular dysfunction. They protect the myocardium by decreasing myocardial fibrosis and ventricular hypertrophy. Until now, these findings have not been proven to be applicable to patients with a systemic right ventricle. Only one study was performed on the patient, finding no benefits on the exercise capacity and the serum neurohormone levels in these patients. However, from this study it is difficult to draw definite conclusions on the role of ARB’s in patients with a systemic right ventricle, as the study was inadequately powered (only 29 patients), had a short follow-up period (only 15 weeks) and had inappropriate and inaccurate endpoints3. Therefore, a large scale, long term trial, with clear and accurate endpoints is essential to provide an optimal and evidence-based long term treatment and a better future for these patients.

Treatment with an angiotensin II receptor blocker (valsartan) stabilizes or improves the functional performance of the systemic right ventricle.

One group receives twice daily a 160 mg tablet of valsartan and the other group receives twice daily a placebo tablet.