ACE-I/ARB Therapy prior to Contrast Exposure: What Should the Clinician Do?

Figure 1

Mechanism of action of ACE-Is/ARBs. ACE-Is act to inhibit the conversion of angiotensin-I to angiotensin-II as well as the formation of transforming growth factor beta-1, which may promote proximal tubular cell injury. Angiotensin receptor antagonists (ARAs) prevent binding of angiotensin-II to its receptor. ACE-Is and ARAs major effect is to decrease intraglomerular pressures and in the setting of hypotension are associated with hypoperfusion of the kidney and a reduction in GFR.