Methods
Between March, 1999, and March, 2001, patients were
randomly assigned, in a double-blind way, candesartan
or matching placebo (figure 1) according to computergenerated
assignment, stratified by site and component
trial, and provided through a coordinating telephone
centre. The assignment code was held at an independent
centre and by the data safety monitoring board. The
initial dose used could be 4 mg or 8 mg candesartan
once daily or matching placebo, decided by the study
physician.19 Study-drug dose could be doubled, as
tolerated, at a minimum of every 2 weeks, to the target
dose of 32 mg once daily, with recommended
monitoring of blood pressure and serum potassium and
creatinine. Study medication could be increased or
decreased in response to the patients’ clinical status, and
algorithms were provided as guidelines for management
of hypotension or renal dysfunction. After the titration
phase, visits were scheduled every 4 months, with a
minimum planned duration of 2 years. Routine safety
laboratory assessments were done in North American
patients at baseline, 6 weeks, 14 months, and yearly
thereafter. Use of conventional heart-failure treatments,
such as blockers, diuretics, digitalis, spironolactone,
and, if appropriate, angiotensin-converting-enzyme
inhibitors, were allowed. After the results of the
Heart Outcomes Prevention Evaluation trial20 were
available, physicians were permitted to use angiotensinconverting-
enzyme inhibitors in CHARM-Preserved
patients who had similar demographic features. Patients
were free to discontinue their participation in the study
at any time. Discontinuations because of patients’
preference or physicians’ decision were recorded and
these patients were followed up for outcomes if possible,
according to the intention-to-treat principle.
The primary outcome of the overall programme was allcause
death. The outcomes in the three component trials
were: cardiovascular death or unplanned admission to
hospital for the management of worsening CHF (primary
outcome); cardiovascular death, admission to hospital for
CHF, or non-fatal myocardial infarction; cardiovascular
death, admission to hospital for CHF, non-fatal
myocardial infarction, or non-fatal stroke; cardiovascular
death, admission to hospital for CHF, non-fatal
myocardial infarction, non-fatal stroke, or coronary
revascularisation; death (any cause) or admission to
hospital for CHF; and development of new diabetes.
We classified all deaths as cardiovascular unless an
unequivocal non-cardiovascular cause was established.
A CHF hospital admission was defined as admission to
hospital necessitated by heart failure and primarily for its
treatment or when heart failure became a major
component of the patient’s hosiptal admission. A patient
admitted for this reason had to show signs and symptoms
of worsening heart failure and require treatment with
intravenous diuretics. Evidence of worsening heart failure
had to include at least one of the following items:
increasing dyspnoea on exertion, orthopnoea, nocturnal
dyspnoea, pulmonary oedema, increasing peripheral
oedema, increasing fatigue or decreasing exercise tolerance,
renal hypoperfusion (ie, worsening renal function), raised
jugular venous pressure, and radiological signs of CHF.
A diagnosis of myocardial infarction was made if the
following conditions were met: creatine kinase or creatine
kinase-MB more than twice the upper limit of normal, or
troponin I or T more than twice the upper limit of normal
if neither creatine kinase or creatine kinase-MB were
available; or three times the upper limit of normal for the
same markers within 24 h of percutaneous transluminal
coronary angioplasty; or five times the upper limit of
normal for the same markers within 24 h of coronary
artery bypass grafting surgery. In addition to these
marker criteria, a patient had to have experienced
electrocardiographic changes in two or more contiguous
leads showing new Q waves (or R waves in V1 or V2), leftbundle-
branch block, or ischaemic ST-T wave changes,
or typical clinical presentation consistent with myocardial
infarction defined as one of the following: cardiac
ischaemic type pain lasting more than 20 min, pulmonary
oedema, or cardiogenic shock not otherwise explained.