Prospective evaluation comparing the effects of enalapril and losartan in left ventricular remodeling after acute myocardial infarction.
BACKGROUND
Previous studies have compared angiotensin receptor blockers and angiotensin-converting enzyme inhibitors in patients with heart failure, but there are few data about the effect of these drugs regarding left ventricular remodeling after myocardial infarction.


METHODS
Fifty-two consecutive patients with first anterior wall myocardial infarction within 24 hours of evolution were randomized to receive enalapril (as much as 20 mg; mean, 14.6 mg), or losartan (as much as 50 mg; mean, 48 mg). Left ventricular ejection fraction and ventricular volumes were analyzed in 2 serial radionuclide ventriculograpies, carried out within 4 days after the infarction (mean, 97.4 +/- 114.2 hours) and after 6 months (mean, 177.7 +/- 16.7 days). Ventriculographies were analyzed by a single blinded observer. Mainly because of the unexpected large SD values obtained, the power of the study to demonstrate equivalence between the groups was only 15.7%.


RESULTS
The differences obtained between the first and the second ventriculographies, for the enalapril and losartan groups, were: for left ventricular ejection fraction, -0.4% +/- 6.6% versus -1.1% +/- 5.9% (P =. 67; 95% CI, 2.77-4.23); for final systolic volume, 0.07 +/- 7.7 mL/m(2) versus -0.2 +/- 6.1mL/m(2) (P =. 85; 95% CI, -3.57-4.26); for final diastolic volume -0.7 +/- 12.1 mL/m(2) versus -3.6 - 9.9 mL/m(2) (P =. 34; 95% CI, -3.22-9.17).


CONCLUSIONS
This study, although underpowered, suggests that neither enalapril nor losartan was superior as compared with each other for left ventricular remodeling after myocardial infarction; however, powerful evidence of equivalence was not provided.
Maia
Lilia Nigro
LN
Hospital de Base, São José do Rio Preto Medical School (FAMERP) and Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil. ucor@famerp.br
Nicolau
José Carlos
JC
Vítola
João V
JV
Santos
Márcio
M
Brandi
Josélia Menin
JM
Joaquim
Marcos Rogério
MR
Baggi
José Mário
JM
Cordeiro
José Antonio
JA
de Godoy
Moacir F
MF
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002216:Captopril; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D019808:Losartan / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology*; D015635:Radionuclide Ventriculography / Q000379:methods; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D016277:Ventricular Function, Left / Q000187:drug effects / Q000502:physiology; D020257:Ventricular Remodeling / Q000187:drug effects* / Q000502:physiology
D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D004656:Enalapril; D002216:Captopril; D019808:Losartan