X1
| Patients having suffered chronic heart failure IV degree of the New York Heart Association during the six previous months. | Inclusion |
X2
| Functional class III or IV at the moment of inclusion, diagnosed as cardiac insufficiency at least six weeks earlier. | Inclusion |
X3
| Patients with an ejection fraction of the left ventricle below 35% during the past six months. | Inclusion |
X4
| Diabetes | Exclusion |
X5
| Renal insufficiency or creatinine above 2.5 mg/dl | Exclusion |
X6
| Congenital cardiopathy | Exclusion |
X7
| Unstable angina | Exclusion |
X8
| Patients with potassium >5 mm/l | Exclusion |
X9
| Hyperkalaemia history | Exclusion |
X10
| Operable valvular disease | Exclusion |
X11
| Primary hepatic failure | Exclusion |
X12
| Cardiac transplant indication | Exclusion |
X13
| Active cancer or any life threatening disease | Conditional |
X14
| Close laboratory monitoring during treatment | Conditional (research process) |
X15
| Potassium supplements were not recommended, except when potassium concentrations in serum were below 3.5 mmol/l | Conditional (research process) |
X16
| Patients had to be in treatment with a loop diuretic and an angiotensin converting enzyme inhibitor if it were tolerated | Conditional (research process) |
X17
| Treatment with digitalis and vasodilators was permitted but not with potassium sparing diuretics | Conditional (research process) |