Antiplatelet Therapy Use after
Discharge among Acute
Myocardial Infarction Patients
with In-hospital Bleeding
Tracy Y. Wang, MD, MHS, Lan Xiao, PhD, Karen P.
Alexander, MD, Sunil V. Rao, MD, Mikhail N. Kosiborod, MD,
John S. Rumsfeld, MD, PhD, John A. Spertus, MD, MPH,
and Eric D. Peterson, MD, MPH
Wang TY et al, Circulation 2008
Background

Antithrombotic therapies are important in the
management of patients with acute myocardial infarction
(AMI), but incur an increased risk of bleeding
complications

Prior studies have established an association between
bleeding during AMI and worse short- and long-term
outcomes

One potential explanation may be that bleeding during
the AMI hospitalization reduces the patient’s subsequent
likelihood of receiving secondary prevention antiplatelet
therapies after hospital discharge
Methods
Total AMI Population in PREMIER Registry
N=2498
In-hospital bleeding or transfusion?
(TIMI major/minor bleeding or
non-CABG transfusion with baseline Hct ≥28)
yes
no
Bleeding
No Bleeding
N = 301
N = 2,197
Patient Follow-up
• 1 month
• 6 months
• 1 year
No Bleeding
Bleeding
N = 2,197
N = 301
P-value
Baseline characteristics
60.3 ± 12.8
65.1 ± 13.7
<.001
Women (%)
Hypertension (%)
Diabetes mellitus (%)
Prior MI (%)
31.1
62.7
28.7
21.4
43.2
70.4
29.6
22.3
<.001
.01
.76
.73
Prior PCI (%)
Prior CABG (%)
Prior CHF (%)
Baseline CrCl (mg/dL)
17.8
13.0
11.2
74.4 ± 29.8
18.9
12.6
18.3
65.6 ± 40.4
.62
.87
<.001
<.001
87.2
61.3
11.4
85.4
57.8
12.0
.39
.24
.79
Age (yrs)
In-hospital procedures
In-hospital cath
In-hospital PCI
In-hospital CABG
Adjusted Discharge Medication Use
Adjusted †OR
6 months
0.45
0.68
0.63
0.31– 0.64
0.50– 0.92
0.46– 0.87
1 year
0.94
0.66– 1.34
Discharge
0.62
0.83
0.42– 0.91
0.59– 1.17
1.06
1.12
0.78– 1.45
0.81– 1.55
1 month
0.76
1.05
0.54– 1.08
0.76– 1.44
6 months
1.09
0.79– 1.51
1 year
0.87
0.63– 1.20
Discharge
0.81
0.65
0.80
0.81
0.60– 1.10
0.48– 0.87
0.59– 1.09
0.58– 1.12
Discharge
Aspirin
Thienopyridine
1 month
1 month
6 months
1 year
Discharge
Beta-blocker
Statin
95% CI
1 month
6 months
1 year
0
1
Less use
2
More use
Antiplatelet Use Stratified by Follow-up Type
1 month
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
P=0.03
P<0.001
75
50
25
100
Thienopyridine Use at 1 month
Aspirin Use at 1 month
100
P=0.006
P<0.001
75
50
25
0
0
Bleeding
Non-bleeding
Bleeding
Non-bleeding
Antiplatelet Use Stratified by Follow-up Type
6 months
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
Aspirin Use at 6 months
P<0.001
P<0.001
75
50
25
0
Bleeding
Non-bleeding
Thienopyridine Use at 6 months
100
100
75
P<0.001
P<0.001
50
25
0
Bleeding
Non-bleeding
Antiplatelet Use Stratified by Follow-up Type
12 months
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
Cardiologist/Cardiac Surgeon
Internist/Family Practitioner/Primary MD
None
Aspirin Use at 12 months
P=0.003
P<0.001
75
50
25
0
Bleeding
Non-bleeding
Thienopyridine Use at 12 months
100
100
75
P<0.001
P<0.001
50
25
0
Bleeding
Non-bleeding
Limitations

Small sample size limited power to assess how timing
of antiplatelet medication resumption influences longterm outcomes

PREMIER did not capture detailed clinical rationale
behind medication adjustments after discharge

Outpatient follow-up (type/intensity) was not prespecified.

Observational analysis subject to unmeasured
confounders despite multivariable adjustment
Conclusions

A significant proportion (12%) of patients with AMI
experience bleeding complications or require nonCABG related transfusions during their AMI
hospitalization

Patients who bleed are older and more likely to have
comorbidities which can contribute to their worse
long-term outcomes

Yet, another explanation for these worse outcomes
might be that these patients are less aggressively
treated with guidelines-recommended AMI therapies
Conclusions

In the setting of a recent bleed, post-AMI patients are
less likely to be discharged on antiplatelet therapies
such as aspirin or thienopyridines

Clinicians may defer re-initiation until “safe” from
further bleeding

However, this treatment gaps persists even up to 6
months after the initial in-hospital event

Patients seen in follow-up by a cardiology specialist
are more likely to be treated with antiplatelet agents
than those seen in follow-up by a primary care
practitioner or those with no clinical follow-up
Implications


While the decision to treat AMI patients with
antiplatelet medications after bleeding is largely based
on clinical intuition, continuity of care is critical as
patients without post-discharge follow-up miss the
opportunity to be evaluated for possible re-initiation of
guidelines recommended secondary prevention
therapies.
Clinicians should continuously reassess the
opportunity to safely re-initiate these medications
after resolution of the bleeding event.