From Baylor College of Medicine, Houston, Tex (J.J.M., C.M.P.); the
Center for Controlled Clinical Trials, School of Public Health, University of
Texas, Houston (L.A.M.); Jacksonville (Fla) Cardiovascular Clinic (D.A.C.);
University of Miami (Fla)/Jackson Memorial Hospital (R.F.S.); Baylor College
of Medicine/Veterans Administration Medical Center, Houston, Tex (G.B.H.);
Internal Medicine of Greer, SC (J.H.); University of Texas Health Science
Center at San Antonio (Tex)/Audie L. Murphy Veterans Hospital (A.J.); St.
Louis (Mo) University School of Medicine (B.R.C.); Schering-Plough
Corporation, Kenilworth, NJ (W.W.); and Schering-Plough Research Institute,
Kenilworth, NJ (H.M.-B.).
Correspondence to John J. Mahmarian, MD, 6550 Fannin St, SM-1246, Houston, TX 77030-2716. E-mail johnj{at}bcm.tmc.edu
Methods and ResultsThis was a randomized, double-blind,
placebo-controlled trial designed to investigate the long-term
(6-month) efficacy of intermittent transdermal
nitroglycerin (NTG) patches on LV remodeling in 291
survivors of AMI. Patients meeting entry criteria had baseline gated
radionuclide angiography (RNA) followed by randomization to placebo or
active NTG patches delivering 0.4-, 0.8-, or 1.6-mg/h. RNA was repeated
at 6 months and 6.5 days after withdrawal of double-blind medication.
The primary study end point was the change in end-systolic
volume index (ESVI). Both ESVI and end-diastolic volume
index (EDVI) were significantly reduced with 0.4-mg/h NTG patches
(-11.4 and -11.6 mL/m2, respectively,
P<.03). This beneficial effect was observed primarily
in patients with a baseline LV ejection fraction
ConclusionsTransdermal NTG patches prevent LV dilation in
patients surviving AMI. The beneficial effects are limited to patients
with depressed LV function and only at the lowest (0.4-mg/h) dose.
Continued administration is necessary to maintain efficacy. Whether
these remodeling effects confer a clinical or survival advantage will
need to be addressed in an adequately powered cardiac event trial.
Nitrates reduce infarct size,11 12 13 prevent acute
LV dilation,12 and limit infarct zone
expansion.12 14 Prolonged nitrate use in animal
models of infarction also limits LV dilation and improves
EF14; however, there is limited information
regarding their long-term effects on remodeling in
humans.15 16 17 This study was designed to
investigate the effects of transdermal nitroglycerin
patches on LV remodeling over a 6-month period in patients surviving
acute Q-wave myocardial infarction.
Patients eligible for enrollment were identified between the third
hospital day until hospital discharge. Exclusion criteria included (1)
severe congestive heart failure, (2) persistent hypotension
(systolic blood pressure <90 mm Hg), (3) sustained
ventricular tachycardia or high-degree AV
block, (4) unstable angina pectoris, (5) a significant noncardiac
illness that would contribute to 6-month morbidity or mortality, or (6)
either a requirement for or a known intolerance to nitrate
preparations.
Patients meeting all entry criteria had baseline gated radionuclide
angiography to measure LVEF and cardiac volumes. Long-acting nitrates
were discontinued a minimum of 48 hours before angiography. All other
cardiovascular medications were allowed, but every
attempt was made to maintain constant dosing throughout the 6-month
study period.
After radionuclide angiography, patients were randomized to
double-blind medication, which was increased at 5- to 7-day intervals
until the randomly assigned dosage (placebo or 0.4, 0.8, or 1.6 mg
nitroglycerin) was achieved. Medication was allowed to
be deescalated to the previously tolerated dosage if side effects
developed. Patients were then maintained on this final dosage for the
6-month study period and evaluated monthly for clinical stability.
Gated radionuclide angiography was used to assess sequential changes in
LVEF and cardiac volumes. The description of this method and its
reproducibility were given previously.19 20
Hemodynamic parameters measured were the LV
EDV, ESV, stroke volume, and EF. All cardiac volumes were indexed to
body surface area. Gated radionuclide angiography was performed at
baseline, after 6 months of double-blind medication (end-point visit
1), and 1 week later after withdrawal of study medication (end-point
visit 2). The radionuclide angiograms were interpreted blinded to
treatment allocation by one experienced investigator (J.J.M.) at the
core laboratory at Baylor College of Medicine.
Statistical Analysis
The baseline patient characteristics of the study population are shown
in Table 1
Nitroglycerin Patch Doses and Therapy
Duration
LV Volume Changes
Changes in the primary end point relative to baseline LVEF are depicted
in Fig 4
Cardiac Volumes After Nitroglycerin Withdrawal
LVEF
Effect of Nitroglycerin Patches on LV Volumes on
the Basis of Concomitant ACE Inhibitor Therapy
In patients not taking an ACE inhibitor at study entry, the
ESVI was significantly reduced among those randomized to 0.4-mg/h
nitroglycerin patches (Table 5
In patients taking an ACE inhibitor at study entry,
nitroglycerin patch therapy did not significantly
reduce ESVI beyond that observed with placebo. This negative result was
due in part to the minimal change in ESVI over the course of the study
in patients assigned to placebo, thereby limiting the detection of a
nitrate effect. However, in the subgroup of patients with an LVEF
Cardiac Events
Selection of LV ESVI as the Primary End Point
Nitrates and LV Remodeling
Comparison With the Remodeling Effects of ACE Inhibitors
A substudy from the SAVE trial examined the effects of captopril in 512
patients with an LVEF <40% who had sequential two-dimensional
echocardiography.9 At a
1-year follow-up, LV EDV and ESV were significantly larger in patients
who received placebo compared with those given active therapy.
Importantly, 1-year survivors had a significantly smaller increase in
LV dimensions compared with those patients who died.
In the present trial, significant reductions in both EDVI and ESVI
were observed but were almost exclusively limited to patients with an
LVEF
Previous Long-term Trials of Nitrates After Acute Myocardial
Infarction
Study Limitations
The effect of nitroglycerin patch therapy on LV
remodeling in patients with anterior and inferior
infarction was not specifically addressed in this study. Rather, we
prospectively chose to analyze our data on the basis of initial
LVEF. As expected, most of the patients with an LVEF
Finally, gated radionuclide angiography was chosen to assess changes in
LVEF and cardiac volumes because it is a precise and reproducible
count-based technique that, unlike two-dimensional
echocardiography, is not dependent on geometric
assumptions.19 20 However, two-dimensional
echocardiography does address other aspects of LV
remodeling, such as regional changes in wall thickness and infarct
expansion, that could not be assessed in this study with nuclear
imaging.
Conclusions
Presented in part at the 69th Scientific Sessions of the American Heart Association, New Orleans, La, November 1996, and previously published in abstract form (Circulation. 1996;94[suppl I]:I-504).
Received June 27, 1997;
revision received January 15, 1998;
accepted January 23, 1998.
2.
Mahmarian JJ, Mahmarian AC, Marks GF, Pratt CM, Verani
MS. Role of adenosine thallium-201 tomography for defining
long-term risk in patients after acute myocardial infarction.
J Am Coll Cardiol. 1995;25:13331340.[Abstract]
3.
Multicenter Postinfarction Research Group. Risk
stratification and survival after myocardial infarction. N
Engl J Med. 1983;309:331336.[Abstract]
4.
Sanz G, Castaner A, Betriu A, Magrina J, Roig E, Coll
S, Pare JC, Navarro-Lopez F. Determinants of prognosis in survivors of
myocardial infarction: a prospective clinical angiographic study.
N Engl J Med. 1987;306:10651070.[Abstract]
5.
White HD, Norris RM, Brown MA, Brandt PWT, Whitlock
RML, Wild CJ. Left ventricular end-systolic volume
as the major determinant of survival after recovery from myocardial
infarction. Circulation. 1987;76:4451.
6.
The CONSENSUS Trial Study Group. Effects of enalapril
on mortality in severe congestive heart failure: results of the
Cooperative North Scandinavian Enalapril Survival Study (CONSENSUS).
N Engl J Med. 1987;316:14291435.[Abstract]
7.
The SOLVD Investigators. Effect of enalapril on
survival in patients with reduced left ventricular ejection
fraction and congestive heart failure: results of the Treatment Trial
of the Studies of Left Ventricular Dysfunction (SOLVD): a
randomized double blind trial. N Engl J Med. 1991;325:293302.[Abstract]
8.
Pfeffer MA, Braunwald E, Moyé LA, Basta L, Brown
EJ Jr, Cuddy TE, Davis BR, Geltman EM, Goldman S, Flaker GC, Klein M,
Lamas GA, Packer M, Rouleau J, Rouleau JL, Rutherford JR, Wertheimer
JH, Hawkins CM, for the SAVE investigators. Effect of captopril on
mortality and morbidity in patients with left ventricular
dysfunction after myocardial infarction: results of the survival and
ventricular enlargement trial. N Engl J
Med. 1992;327:669677.[Abstract]
9.
St John Sutton M, Pfeffer MA, Plappert T, Rouleau J-L,
Moyé LA, Dagenais GR, Lamas GA, Klein M, Sussex B, Goldman S,
Menapace FJ Jr, Parker JO, Lewis S, Sestier F, Gordon DF, McEwen P,
Bernstein V, Braunwald E, for the SAVE Investigators. Quantitative
two-dimensional echocardiographic measurements are
major predictors of adverse cardiovascular events after
acute myocardial infarction: the protective effects of captopril.
Circulation. 1994;89:6875.
10.
Konstam MA, Rousseau MF, Kronenberg MW, Udelson JE,
Melin J, Stewart D, Dolan N, Edens TR, Ahn S, Kinan D, Howe DM,
Kilcoyne L, Metherall J, Benedict C, Yusuf S, Pouleur H, for the SOLVD
Investigators. Effects of the angiotensin converting enzyme
inhibitor enalapril on the long-term progression of left
ventricular dysfunction in patients with heart failure.
Circulation. 1992;86:431438.
11.
Jugdutt BI, Becker LC, Hutchins GM, Bulkley BH, Reid
PR, Kallman CH. Effect of intravenous
nitroglycerin on collateral blood flow and infarct size
in the conscious dog. Circulation. 1981;63:1728.
12.
Jugdutt BI, Warnica JW. Intravenous
nitroglycerin therapy to limit myocardial infarct size,
expansion and complications: effect of timing, dosage and infarct
location. Circulation. 1988;78:906919.
13.
Jaffe AS, Geltman EM, Tiefenbrunn AJ, Ambos HD, Strauss
HD, Sobel BE, Roberts R. Reduction of infarct size in patients with
inferior infarction with intravenous glyceryl
trinitrate: a randomised study. Br Heart J. 1983;49:452460.
14.
Jugdutt BI, Khan MI. Effect of prolonged nitrate
therapy on left ventricular remodeling after canine acute
myocardial infarction. Circulation. 1994;89:22972307.
15.
Michorowski BL, Tymchak WJ, Jugdutt BI. Improved left
ventricular function and topography by prolonged
nitroglycerin therapy after acute myocardial
infarction. Circulation. 1987;76(suppl IV):IV-128. Abstract.
16.
Jugdutt BI, Michorowski BL, Tymchak WJ. Improved left
ventricular function and topography by prolonged
nitroglycerin therapy after acute myocardial
infarction. Z Kardiol. 1989;78(suppl 2):127129.
17.
Jugdutt BI, Tymchak WJ, Humen DP, Gulamhusein S, Tang
SB. Effect of thrombolysis and prolonged captopril and
nitroglycerin on infarct size and remodeling in
transmural myocardial infarction. J Am Coll Cardiol. 1992;19:205A. Abstract.
18.
Pratt CM, Mahmarian JJ, Morales-Ballejo H, Casareto R,
Moyé LA, for the Transdermal Nitroglycerin
Investigators Group. The long-term effects of intermittent transdermal
nitroglycerin on left ventricular
remodeling after acute myocardial infarction: design of a randomized,
placebo controlled multicenter trial. Am J Cardiol. 1998;81:719724.[Medline]
[Order article via Infotrieve]
19.
Verani MS, Gaeta J, LeBlanc AD, Poliner LR,
Phillips L, Lacy JL, Thornby JI, Roberts R. Validation of left
ventricular volume measurements by radionuclide
angiography. J Nucl Med. 1985;26:13941401.
20.
Mahmarian JJ, Moyé L, Verani MS, Eaton T, Francis
M, Pratt CM. Criteria for the accurate interpretation of changes in
left ventricular ejection fraction and cardiac volumes as
assessed by rest and exercise gated radionuclide angiography.
J Am Coll Cardiol. 1991;18:112119.[Abstract]
21.
Seals AA, Pratt CM, Mahmarian JJ, Tadros S, Kleiman N,
Roberts R, Verani MS. Relation of left ventricular dilation
during acute myocardial infarction to systolic
performance, diastolic dysfunction, infarct size
and location. Am J Cardiol. 1988;61:224229.[Medline]
[Order article via Infotrieve]
22.
Pfeffer MA, Lamas GA, Vaughan DE, Parisi AF, Braunwald
E. Effect of captopril on progressive left ventricular
dilatation after anterior myocardial infarction. N Engl
J Med. 1988;319:8086.[Abstract]
23.
Pfeffer MA, Braunwald E. Ventricular
remodeling after myocardial infarction. Experimental observations and
clinical implications. Circulation. 1990;81:11611172.
24.
Erlebacher JA, Weiss JL, Weisfeldt ML, Bulkley BH.
Early dilation of the infarcted segment in acute transmural myocardial
infarction: role of infarct expansion in acute left
ventricular enlargement. J Am Coll Cardiol. 1984;4:201208.[Abstract]
25.
Erlebacher JA, Weiss JL, Eaton LW, Kallman C, Weisfeldt
ML, Bulkley BH. Late effects of acute infarct dilation on heart size: a
two-dimensional echocardiographic study. Am
J Cardiol. 1982;49:11201126.[Medline]
[Order article via Infotrieve]
26.
Jugdutt BI, Khan MI, Jugdutt SJ, Blinston GE. Impact of
left ventricular unloading after late reperfusion of canine
anterior myocardial infarction on remodeling and function using
isosorbide-5-mononitrate. Circulation. 1995;92:926934.
27.
Jugdutt BI, Khan MI, Jugdutt SJ, Blinston GE. Combined
captopril and isosorbide dinitrate during healing after myocardial
infarction: effect on ventricular remodeling, function,
mass and collagen. J Am Coll Cardiol. 1995;25:10891096.[Abstract]
28.
Yusuf S, Wittes J, Probstfield J, Tyroler HA.
Analysis and interpretation of treatment effects in subgroups
of patients in randomized clinical trials. JAMA. 1991;266:9398.
29.
GISSI-3 (Gruppo Italiano per lo Studio della
Sopravivenza nell'infarto Miocardico). GISSI-3: effects of
lisinopril and transdermal glyceryl trinitrate singly and
together on 6-week mortality and ventricular function after
acute myocardial infarction. Lancet. 1994;343:11151122.[Medline]
[Order article via Infotrieve]
30.
ISIS-4 (Fourth International Study of Infarct
Survival) Collaborative Group. ISIS-4: a randomised factorial trial
assessing early oral captopril, oral mononitrate, and
intravenous magnesium sulphate in 58,050 patients with
suspected acute myocardial infarction. Lancet. 1995;345:669685.[Medline]
[Order article via Infotrieve]
31.
Popovic AD, Neskovic AN, Marinkovic J, Thomas JD.
Acute and long-term effects of thrombolysis after
anterior wall acute myocardial infarction with serial assessment of
infarct expansion and late ventricular remodeling.
Am J Cardiol. 1996;77:446450.[Medline]
[Order article via Infotrieve]
© 1998 American Heart Association, Inc.
Clinical Investigation and Reports
Transdermal Nitroglycerin Patch Therapy Improves Left Ventricular Function and Prevents Remodeling After Acute Myocardial Infarction
Results of a Multicenter Prospective Randomized, Double-Blind, Placebo-Controlled Trial
![]()
Abstract
Top
Abstract
Introduction
Methods
Results
Discussion
References
BackgroundNitrates are widely used
in the treatment of angina in patients with acute myocardial infarction
(AMI). Short-term administration prevents left ventricular
(LV) dilation and infarct expansion. However, little information is
available regarding their long-term effects on LV remodeling in
patients surviving Q-wave AMI.
40% (
ESVI, -31
mL/m2;
EDVI, -33 mL/m2; both
P<.05) and only at the 0.4-mg/h dose. After NTG patch
withdrawal, ESVI significantly increased but did not reach pretreatment
values.
Key Words: remodeling myocardial infarction nitroglycerin
![]()
Introduction
Top
Abstract
Introduction
Methods
Results
Discussion
References
Event-free survival
after acute myocardial infarction is most influenced by the extent of
residual myocardial ischemia1 2 and the
global left ventricular (LV) ejection fraction
(EF).3 4 Patients with LV dysfunction are more
likely to have progressive LV dilation, which is an independent
determinant of long-term survival.5 Recent
studies demonstrate that ACE inhibitors improve survival in
patients with chronic LV dysfunction6 7 and in
those after acute myocardial infarction.8 This
benefit is thought to be at least partially due to prevention of LV
dilatation.9 10
![]()
Methods
Top
Abstract
Introduction
Methods
Results
Discussion
References
Details of the study design are reported elsewhere by Pratt et
al (Fig 1
).18
Briefly, this was a randomized, double-blind, placebo-controlled,
multicenter trial designed to investigate the efficacy of intermittent
nitroglycerin patch therapy delivering 0.4, 0.8, and
1.6 mg/h over a 6-month period in patients surviving an acute Q-wave
myocardial infarction. The study was conducted between July 6, 1992,
and December 29, 1994.

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Figure 1. Study design. MI indicates myocardial infarction;
NTG, nitroglycerin; and RNA, radionuclide
angiography.
This study was not powered to detect a difference in 6-month
cumulative cardiac event rates among the four treatment groups. Rather,
the prospectively defined primary end-point variable was the change
in ESVI as assessed by sequential gated radionuclide angiography. Other
variables assessed were (1) temporal changes in LVEF, EDVI, and
stroke volume index and (2) subsequent cardiac event rates over the
6-month time interval. Prospectively defined subgroup analyses
were performed based on baseline LVEF dichotomized at 40% and ACE
inhibitor use. This study had >90% power to detect an
11-mL/m2 absolute change in ESVI between
treatment groups assuming 50 to 60 patients per group. All data
analyses were performed as intention to treat. Unless otherwise
specified, all data are reported as mean±SD. A value of
P<.05 was considered significant.
![]()
Results
Top
Abstract
Introduction
Methods
Results
Discussion
References
Patient Population
Two hundred ninety-one patients were randomized to one of four
treatment limbs (77 to placebo and 75 to
0.4-mL/m2, 71 to 0.8-mg/h, and 68 to 1.6-mg/h
nitroglycerin patches), and 282 had a baseline gated
radionuclide angiogram (Fig 2
). Of these
latter patients, 245 had a repeat study at end-point visit 1, and 243
had one at end-point visit 2.

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Figure 2. Sequence of gated radionuclide angiography among
randomized patients in the four treatment limbs. Abbreviations as in
Fig 1
, and CHF indicates congestive heart failure; Pt, patient.
. No significant differences
between the four randomized groups were observed in any of the
demographic variables. Approximately 50% of the patients had
anterior infarction and most patients were in New York Heart
Association class I. Most patients were on aspirin and ß-blockers at
the time of randomization, and approximately one third were taking
calcium antagonists and ACE inhibitors. The
mean LVEF was not statistically different among the four treatment
groups, and 35% of patients had an EF
40%. The four groups were
well balanced at baseline as to the primary end-point variable (ie,
ESVI) (Table 2
). Other volume
measurements were likewise similar in the randomized patients.
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Table 1. Baseline Characteristics
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Table 2. Baseline Hemodynamic Results in the
Four Treatment Groups
All patients randomized to placebo and 0.4-mg
nitroglycerin patches continued on this regimen
throughout the trial. Protocol design allowed downtitration if side
effects occurred at higher doses (Table 3
). Accordingly, 60 of 71 patients
randomized to 0.8-mg/h patches (85%) were maintained on the assigned
dosage, whereas 11 patients had their dose decreased to 0.4-mg/h.
Forty-nine of 68 patients (72%) randomized to 1.6-mg/h patches
continued on this dosage throughout the study, but 11 patients were
downtitrated to the 0.4-mg/h dose and 8 to the 0.8-mg/h dosage. Despite
downtitration of study medication in certain patients, the mean doses
of nitroglycerin administered were still significantly
higher in patients randomized to 0.8- and 1.6-mg/h patches (0.74 and
1.31, respectively) compared to those given 0.4-mg/h patches. The major
reasons for downtitration of study medication in these 30 patients were
as follows: severe headache (40%), dizziness (27%), hypotension
(20%), and skin reactions to the patch (13%). Compliance with study
medication was comparably high (>90%) in all four treatment groups.
Randomized drug therapy was continued for at least 5 months in 91% of
patients on placebo and for 81% of patients on 0.4-mg/h, 77% on
0.8-mg/h, and 72% on 1.6-mg/h patches.
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Table 3. Nitroglycerin Patch Dosage by
Treatment Group
The primary end point of this study was the LV ESVI. During the
6-month study period, the mean LV EDVI and ESVI both increased in
patients assigned to placebo. Conversely, EDVI and ESVI were
significantly reduced on active therapy, but a statistically
significant effect was limited to patients assigned to the 0.4-mg/h
nitroglycerin patch dosage (P<.03) (Fig 3
). These results were due to a
combination of progressive LV dilation in patients receiving placebo
and a reduction in cardiac volumes among patients receiving 0.4-mg/h
nitroglycerin patches. Stroke volume index did not
significantly change from baseline to end-point visit 1 for patients on
placebo or active patch therapy.

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Figure 3. Changes in LV EDVI and ESVI (mL/m2)
from baseline to end-point visit 1 in the four randomized treatment
groups. Only the 0.4-mg/h nitroglycerin (NTG) patch
dose significantly reduced cardiac volumes. Data are presented
as mean±SEM.
. Almost the entire therapeutic
effect on LV remodeling was observed in patients with a baseline LVEF
40%. Patients with an LVEF >40% had no significant change in ESVI
over the duration of the study on placebo or active patch therapy.
However, in patients with an LVEF
40%, the ESVI increased by
19.7±81 mL/m2 on placebo but decreased by
11.1±17 mL/m2 on 0.4-mg/h active patch therapy
(P<.05). Likewise, the EDVI increased by 25±78
mL/m2 on placebo but decreased by 8±22
mL/m2 on the 0.4-mg/h dose (P<.05).
As in the overall analysis, significant reductions in cardiac
volumes occurred only in patients receiving the 0.4-mg/h dose.

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Figure 4. Changes in LV ESVI from baseline to end-point
visit 1 based on initial LVEF. Same format as in Fig 3
. No significant
changes in LV ESVI were noted in patients with an LVEF >40%. However,
in patients with an LVEF
40%, LV ESVI dramatically increased in
patients assigned to placebo but was significantly reduced in those
randomized to 0.4-mg/h nitroglycerin (NTG) patch
therapy. Data are presented as mean±SEM.
After study medication was discontinued for a mean of 6.5 days,
gated radionuclide angiography was repeated. No significant changes in
EDVI or ESVI occurred in patients randomized to placebo (Table 4
). In contrast, patients assigned to
0.4-mg/h nitroglycerin patches had a significant
increase in both EDVI and ESVI (5.7±12.1 and 4.2±7.7, respectively;
P<.05). Patients assigned to 0.8- and 1.6-mg/h patches had
a smaller increase in cardiac volumes after the study medication was
discontinued. Although the salutary effects of
nitroglycerin patches were partially reversed after
study drug withdrawal, there remained a significant reduction in ESVI
compared with placebo at the 0.4-mg/h dose (P=.038).
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Table 4. LV Volume Changes After Withdrawal of Double-Blind
Medication
The baseline LVEF was similar among all four treatment groups
(Table 2
). The mean LVEF on placebo did not significantly change from
baseline (47±12%) to end-point visit 1 (47±12%) or 2 (47±13%).
However, compared with placebo, there was a significant overall
increase in LVEF on active patch therapy from 45±13% to 48±13%
(P=.031). Likewise, the LVEF significantly increased from
baseline to end-point visit 1 at both the 0.4- and 1.6-mg/h doses (Fig 5
). We have previously demonstrated that
a
7% change in LVEF defines the 95% confidence limit for describing
a real change beyond the intrinsic variability associated with gated
radionuclide angiography.17 Significantly more
patients randomized to nitroglycerin patch therapy had
a
7% increase in LVEF compared with those administered placebo (23%
versus 11%, P<.01).

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Figure 5. Changes in LVEF from baseline to end-point visits
1 and 2 in the four randomized treatment groups. Patients on placebo
had no significant change in LVEF over the course of the study. The
improvement in LVEF observed in the 0.4- and 1.6-mg/h
nitroglycerin (NTG) patch groups was maintained even
after withdrawal of double-blind medication. Data are presented
as mean±SEM.
A prospectively defined analysis was to evaluate the
interaction of nitroglycerin patch therapy and ACE
inhibitors on ESVI. Of the 245 randomized patients who had
a repeat radionuclide angiogram, 79 (32%) were taking an ACE
inhibitor at study entry (Table 5
). Of the 79 patients with an LVEF
40%, 42 (53%) were on an ACE inhibitor compared with 37
of 166 patients (22%) with an LVEF >40%. The distribution of ACE
inhibitor use was not significantly different among the
four treatment groups.
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Table 5. Changes in ESVI From Baseline to End-Point Visit 1
on the Basis of ACE Inhibitor Therapy
). This occurred
regardless of initial LVEF. In patients with an LVEF
40%, the ESVI
increased by
34 mL/m2 in patients on placebo
but decreased by 22 mL/m2 in those assigned to
0.4-mg/h patches.
40%, a 10-mL/m2 difference in ESVI was
observed between those assigned to placebo versus 0.4-mg/h patches.
Although this analysis was underpowered to detect a
statistically significant difference because of small sample sizes (24
patients), the magnitude of the change in ESVI closely paralleled
that observed in the main trial.
Cardiac event rates over the 6-month period were not significantly
different between the placebo and active treatment groups (Table 6
).
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Table 6. Clinical End Points by Therapy Group
![]()
Discussion
Top
Abstract
Introduction
Methods
Results
Discussion
References
The results of this study provide the first evidence of a
long-term pharmacodynamic effect on LV remodeling with intermittent (12
hours on and off) nitroglycerin patch therapy initiated
within 1 week after acute myocardial infarction and continued for 6
months. The prevention of LV dilatation by
nitroglycerin patches in this study is most likely due
to an acute pharmacological effect rather than a permanent structural
alteration, as evidenced by the observed diminution in the magnitude of
LV volume reduction following study drug withdrawal after only 1 week.
As might be expected, the remodeling effects of
nitroglycerin patches were seen primarily in patients
with poor LV systolic function (LVEF
40%) and large volumes
at baseline. Of interest is the fact that although the 0.4-mg/h dose
resulted in a statistically significant reduction in LV volumes
compared with placebo, higher nitroglycerin doses (up
to a fourfold-higher dose range) prevented remodeling to a lesser
degree. A reasonable inference is that nitroglycerin
tolerance may have limited efficacy at the higher doses of patch
therapy used in this study.
Previous studies have demonstrated the prognostic importance of
the LV ESV, particularly when myocardial dysfunction is present
after acute infarction.5 9 LV dilatation may
develop within the initial 24 hours of acute infarction presumably as a
compensatory mechanism for maintaining stroke
volume.21 This is particularly true in patients
with anterior wall infarcts who generally have the largest extent of
initial LV dysfunction and therefore are most likely to develop early
infarct zone expansion.21 22 Over the ensuing
months, structural and geometric changes occur that entail scar
formation and thinning of the infarct zone, as well as
hypertrophy and dilatation of noninfarcted
regions.23 24 25 The initial loss of
myocardium, if large enough, leads to progressive LV
dilation, increasing wall stress, further LV dysfunction, and
ultimately end-stage heart failure. This cascade of events may explain
why ESVI is such an important long-term prognostic indicator. Gated
radionuclide angiography was used in the present study because it
is an accurate technique for measuring sequential changes in LV
volumes.20 ESVI was chosen as the primary study
end point because it is a readily quantifiable variable of known
prognostic importance. The degree to which
nitroglycerin patches could limit increases in LV
volumes and thereby improve hemodynamics after acute
infarction would seem a reasonable surrogate end point for cardiac
events.
Nitrates in the early postinfarction period reduce infarct
size11 12 13 and limit LV expansion and thinning
within the infarct zone.12 14 These beneficial
effects may result from a reduction in LV
preload/afterload,26 improvement in myocardial
blood flow to the infarct and noninfarct border
zones,11 and sustained integrity of the
myocardial collagen matrix.27 Prolonged nitrate
therapy during infarct healing may be more efficacious than short-term
treatment. In a recent trial of acute infarction in dogs, 2 weeks of
either transdermal or oral dinitrate preparations significantly reduced
LV volumes, LV cavity expansion, and aneurysm formation
compared with placebo.14 However, animals that
received nitrates over a 6-week period had less LV dilation than those
treated for only 2 weeks, with a significant improvement in LVEF. The
results of the present trial closely reflect these animal data in
that at least one dose of intermittent long-term nitrate patch therapy
significantly reduced LV volumetric indexes and improved LVEF compared
with placebo.
The results we report are directionally similar to those
found in trials assessing the effects of ACE
inhibitors.9 10 In the SOLVD study, a
cohort of 56 patients with chronic symptomatic LV
dysfunction (EF <35%) underwent serial gated radionuclide angiography
at baseline and again at 1 year.10 Patients in
the placebo group had progressive LV dilation over the ensuing year,
with significant increases in EDV and ESV. However, in those treated
with enalapril, both volumetric indexes significantly decreased over
time, with a shift in the pressure volume curve to the left and an
improvement in LVEF. Of note, after withdrawal of enalapril for only 2
weeks, LV volumes increased to pretherapy levels but were still
significantly less than those observed with placebo.
40%. The nitrate effect was most pronounced in patients not
taking ACE inhibitors, presumably because patients
receiving ACE inhibitors had only minimal subsequent LV
dilation. Nonetheless, even in patients taking an ACE
inhibitor, the ESVI was reduced by 10
mL/m2 in those with an LVEF
40% who were
assigned to 0.4-mg/h nitroglycerin patches. This
difference did not reach statistical significance because of the small
sample size (24 patients). However, the magnitude of the reduction in
ESVI within this subgroup was consistent with the reduction
observed in the main trial at the 0.4-mg/h dose. These results imply
that nitrates may further reduce LV dilation beyond that achieved with
ACE inhibitors alone.28 The ACE
inhibitor trials clearly support the concept that
preventing LV enlargement improves clinical outcome. Our trial was not
powered to evaluate whether preventing LV dilation with nitrates might
also confer such a survival benefit.
Two large multicenter trials involving almost 80 000 patients
have recently addressed whether transdermal
nitroglycerin therapy over 6
weeks29 or isosorbide mononitrate treatment over
4 weeks30 can reduce cardiac events in patients
surviving acute myocardial infarction. In GISSI-3, there was a trend
toward an overall reduction in cardiac events with nitrate therapy
(relative risk, 0.94; 95% confidence interval, 0.87 to 1.02;
P=.12), which reached statistical significance among the
elderly and women.29 Likewise, ISIS-4 showed no
significant difference in overall mortality with isosorbide mononitrate
but did demonstrate an early survival benefit.30
Although these results are not as impressive as those reported for ACE
inhibitors, several comments about study design are
noteworthy. First, in both ISIS-4 and GISSI-3, some 50% to 60% of
patients in the placebo group were on open-label nitrate preparations,
which invariably limited their ability to detect a survival advantage
with double-blind medication. Second, only 5% of patients in GISSI-3
and an unknown percentage in ISIS-4 had a depressed LVEF. This is an
important limitation because the beneficial effects of nitrates on LV
remodeling in our study were almost exclusively observed in patients
with depressed LV function.
This study assessed the long-term effects of intermittent
nitroglycerin patch therapy on LV remodeling in
survivors of acute myocardial infarction. Thrombolytic
therapy17 31 and intravenous
nitroglycerin12 administered
during acute infarction are also reported to limit subsequent LV
remodeling. These medications were evenly distributed among the four
treatment groups at the time of randomization. Whether other
medications, such as ß-blockers or calcium antagonists,
interact with nitroglycerin to alter remodeling cannot
be determined from this study; however, these medications were also
evenly distributed across all treatment groups.
40% (78%) had
an anterior infarction. Because the beneficial effects of
nitroglycerin patches were almost exclusively limited
to patients with an LVEF
40%, it seems reasonable to surmise that
patients with anterior infarction would benefit most from this form of
therapy. However, nitroglycerin patch therapy may also
be beneficial in patients with inferior infarction who have
an LVEF
40%.
Intermittent transdermal nitroglycerin patch
therapy at a dose of 0.4-mg/h prevents LV dilation and improves LVEF in
patients surviving acute myocardial infarction. These
hemodynamic effects are predominantly observed in
patients with depressed LV function who are most prone to progressive
cardiac dilation, if untreated. Whether improvement in LV function and
geometry with nitrates will ultimately confer a clinical or survival
advantage in patients with LV dysfunction will need to be addressed in
an adequately powered cardiac event trial.
![]()
Selected Abbreviations and Acronyms
EDV
=
end-diastolic volume
EDVI
=
end-diastolic volume index
EF
=
ejection fraction
ESV
=
end-systolic volume
ESVI
=
end-systolic volume index
LV
=
left ventricular
LVEF
=
left ventricular ejection fraction
![]()
Acknowledgments
Research was funded through a grant from Schering-Plough
Research Institute, Kenilworth, NJ.
![]()
Footnotes
Guest editor for this article was Marc A. Pfeffer, MD, Brigham & Women's Hospital, Boston, Mass.
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References
Top
Abstract
Introduction
Methods
Results
Discussion
References
1.
Gibson RS, Watson DD, Craddock GB, Crampton RS,
Kaiser DL, Denny MJ, Beller GA. Prediction of cardiac events after
uncomplicated myocardial infarction: a prospective study comparing
predischarge exercise thallium-201 scintigraphy and
coronary angiography. Circulation. 1983;68:321336.
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