Patients with acute coronary syndromes and elevated levels of natriuretic peptides: the results of the AVANT GARDE-TIMI 43 Trial

Abstract

Aims: Elevated natriuretic peptides (NPs) are associated with an increased cardiovascular risk following acute coronary syndromes (ACSs). However, the therapeutic implications are still undefined. We hypothesized that early inhibition of renin-angiotensin-aldosterone system (RAAS) in patients with preserved left ventricular function but elevated NPs but following ACS would reduce haemodynamic stress as reflected by a greater reduction NP compared with placebo.

Methods and results: AVANT GARDE-TIMI 43 trial, a multinational, double-blind trial, randomized 1101 patients stabilized after ACS without clinical evidence of heart failure or left ventricular function <or=40% but with an increased level of NP 3-10 days after admission to aliskiren, valsartan, their combination, and placebo. The primary endpoint was the change in NT-proBNP from baseline to Week 8. NT-proBNP declined significantly in each treatment arm, including placebo, by Week 8, though there were no differences in the reduction between treatment strategies (42% in placebo, 44% in aliskiren, 39% in valsartan, and 36% in combination arm). Although several subgroups had higher baseline levels of NP and greater reductions over the study period, there were no differences among treatment groups in any subgroup. There were no differences in clinical outcomes but there were more adverse events, including serious events and adverse events leading to early study drug discontinuation, in patients treated with active therapy.

Conclusion: In this study of a high-risk population with elevated levels of NPs but relatively preserved systolic function and no evidence of heart failure following ACS, there was no evidence for a benefit of early initiation of inhibition of RAAS with valsartan, aliskiren, or their combination compared with placebo with respect to a reduction in NP over 8 weeks of therapy. Moreover, adverse events were reported more frequently in patients assigned to active therapy.