Carvedilol
and Left Ventricular Remodeling Following Acute Myocardial
Infarction: Variable Effects Over Time and Possible Mechanisms.
The CAPRICORN Echo Substudy
Robert
N Doughty
Authors: Norman Sharpe; Helen Walsh; Gillian A Whalley;
Robert N Doughty; Greg D Gamble
Background: The CAPRICORN
Echo Substudy has previously reported reverse remodeling
with carvedilol (C) at 6 months. The earlier effects of
C on remodeling and mechanisms of benefit are uncertain.
Methods: The substudy was
undertaken at 12 sites in New Zealand, Australia and Spain.
Quantitative 2-D echocardiograms were recorded at baseline,
1, 3 & 6 months of study treatment. LV end-diastolic
& end-systolic volumes (LVEDV and LVESV) & wall
motion score index (ASE) were measured off-line at the Core
Echo Lab.
Results: 129 patients
were included. Heart rate was decreased by 7-8bpm between
the C and placebo groups at 1, 3 & 6 months. Between
group changes in blood pressure (BP) at 1, 3 and 6 months
were: 7/7 (p<0.05), 6/2 (p=NS) and 3/1mmHg (p=NS) respectively.
Remodeling effects are shown in the table. At one month
there was an improvement in SV and LVEF associated with
the reduction in HR and BP. Improvement in wall motion score
was also evident at 1 month, suggesting an early functional
improvement. These changes were maintained at 3 months.
In addition, at 6 months there were significant reductions
in LVEDV and LVESV with C.
Conclusions: The early
effects of carvedilol appear primarily associated with the
reduction in heart rate and vasodilating properties of carvedilol.
The reverse remodeling effects are not evident early but
are significant and substantial at 6 months.
|
BL to 1 mth
|
BL to 3 mths
|
BL to 6 mths |
LVEDV, ml |
-1.1
|
-2.1
|
-8.6* |
LVESV, ml |
-6.3
|
-7.2
|
-10.8* |
SV, ml |
+5.5*
|
+4.7*
|
+2.3 |
LVEF, % |
+3.8*
|
+4*
|
+4.1* |
WMSI |
-0.2*
|
-0.16 |
-0.11* |
Values
= mean change between groups.
*p<0.05 carvedilol vs placebo |
|