Candesartan was studied in two heart failure outcome studies: 1. The Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity trial in patients intolerant of ACE inhibitors (CHARM–Alternative), 2. CHARM–Added in patients already receiving ACE inhibitors. Both studies were international double-blind, placebo-controlled trials in patients with NYHA class II - IV heart failure and LVEF ≤40%. In both trials, patients were randomized to placebo or candesartan cilexetil (initially 4-8 mg once daily, titrated as tolerated to 32 mg once daily) and followed for up to 4 years. Patients with serum creatinine ≥ 3 mg/dL, serum potassium ≥ 5.5 mEq/L, symptomatic hypotension or known bilateral renal artery stenosis were excluded. The primary end point in both trials was time to either cardiovascular death or hospitalization for heart failure.

CHARM–Alternative included 2028 subjects not receiving an ACE inhibitor due to intolerance. The mean age was 67 years and 32% were female, 48% were NYHA II, 49% were NYHA III, 4% were NYHA IV, and the mean ejection fraction was 30%. Sixty-two percent had a history of myocardial infarction, 50% had a history of hypertension, and 27% had diabetes. Concomitant drugs at baseline were diuretics (85%), digoxin (46%), beta-blockers (55%), and spironolactone (24%). The mean daily dose of candesartan cilexetil was approximately 23 mg and 59% of subjects on treatment received 32 mg once daily.

After a median follow-up of 34 months, there was a 23% reduction in the risk of cardiovascular death or heart failure hospitalization on candesartan cilexetil (p<0.001), with both components contributing to the overall effect (Table 1).

In CHARM–Added, 2548 subjects receiving an ACE inhibitor were randomized to candesartan cilexetil or placebo. The specific ACE inhibitor and dose were at the discretion of the investigators, who were encouraged to titrate patients to doses known to be effective in clinical outcome trials, subject to patient tolerability. Forced titration to maximum tolerated doses of ACE inhibitor was not required.

The mean age was 64 years and 21% were female, 24% were NYHA II, 73% were NYHA III, 3% were NYHA IV, and the mean ejection fraction was 28%. Fifty-six percent had a history of myocardial infarction, 48% had a history of hypertension, and 30% had diabetes. Concomitant drugs at baseline in addition to ACE inhibitors were diuretics (90%), digoxin (58%), beta-blockers (55%), and spironolactone (17%). The mean daily dose of candesartan cilexetil was approximately 24 mg and 61% of subjects on treatment received 32 mg once daily.

After a median follow-up of 41 months, there was a 15% reduction in the risk of cardiovascular death or heart failure hospitalization on candesartan cilexetil (p=0.011), with both components contributing to the overall effect (Table 2). There was no evident relationship between dose of ACE inhibitor and the benefit of candesartan cilexetil.

In these two studies, the benefit of candesartan cilexetil in reducing the risk of CV death or heart failure hospitalization (18% p<0.001) was evident in major subgroups (see Figure), and in patients on other combinations of cardiovascular and heart failure treatments, including ACE inhibitors and beta-blockers.

Figure. CV Death or Heart Failure Hospitalization in Subgroups – LV Systolic Dysfunction Trials