Enalapril versus Digoxin in Patients with Congestive Heart failure: A Multicenter Study (Canadian Enalapril versus Digoxin Study Group) - DIG Enalapril


Digoxin and enalapril for mortality in mild congestive heart failure.


Digoxin and Enalapril exhibit different clinical efficacy in treatment of mild heart failure.

Study Design

Study Design:

Patients Screened: 155
Patients Enrolled: 145
NYHA Class: II=65%, III=35%
Mean Follow Up: 3 months
Mean Patient Age: 59
Female: 25
Mean Ejection Fraction: 30% (measured in 53% of patients)

Patient Populations:

LV dysfunction (EDD > 6 cm or % FS < 25% or EF < 50%)
Physical signs or chest x-ray evidence of left ventricular dysfunction at some time in the past


ACE inhibitor in previous month; other vasodilator therapy
Unstable angina, MI, CVA within 3 months
Hypertension or clinically important renal, hepatic, or hematologic disorders
Valvular or congenital heart disease
Hypertrophic cardiomyopathy
Atrial arrhythmias
Use of medications known to interact with digoxin
History of digoxin toxicity
Renal insufficiency with creatinine > 1.5 or BUN > 25 mg/dl
Inability to exercise because of co-morbid conditions

Primary Endpoints:

Clinical outcome and functional capacity, improvement equals a decrease in functional class of at least one category with worsening equal to increase in functional class of at least one category or withdrawal from study.
Treadmill exercise time.
Change in echocardiographic dimensions.

Secondary Endpoints:

Rest and exercise heart rate, blood pressure and rate-pressure product.
Perceived exertion after each exercise stage.

Drug/Procedures Used:

Enalapril (average 19 mg/day)
Digoxin (average 0.28 mg/day)
Echocardiography, exercise treadmill testing obtained at baseline, 4 weeks and 14 weeks.

Concomitant Medications:

Furosemide (100%) - average 47 mg/day

Principal Findings:

Improved clinical outcome with Enalapril compared to Digoxin in both 4 and 14 weeks.

Exercise time and left ventricular function improved in both groups with no significant difference between groups (no placebo group).

Rate pressure product and subjectively evaluated exertion during submaximal exercise were reduced only in the Enalapril group.


"Although the majority of patients in both groups did well, those receiving Enalapril experienced fewer adverse clinical events and had less fatigue during maximal exercise." (From Abstract)


1. J Am Coll Cardiol 1991;18:1602-9. Final results

Clinical Topics: Heart Failure and Cardiomyopathies, Noninvasive Imaging, Acute Heart Failure, Echocardiography/Ultrasound

Keywords: Enalapril, X-Rays, Digoxin, Heart Failure, Ventricular Dysfunction, Left, Echocardiography, Exercise Test

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