Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Antiplatelet therapy was better than anticoagulant therapy after coronary stenting

ACP J Club. 1997 Jul-Aug;127:4. doi:10.7326/ACPJC-1997-127-1-004


Source Citation

Schömig A, Neumann FJ, Walter H, et al. Coronary stent placement in patients with acute myocardial infarction: comparison of clinical and angiographic outcome after randomization to antiplatelet or anticoagulant therapy. J Am Coll Cardiol. 1997 Jan;29:28-34.


Abstract

Objective

To compare the effectiveness of antiplatelet (AP) therapy with that of anticoagulant (AC) therapy after successful stent placement in acute myocardial infarction.

Design

Randomized controlled trial with 6-month follow-up.

Setting

A hospital in Germany.

Patients

123 patients (mean age 60 y, 76% men) who had had recent myocardial infarction (< 48 h) and successful coronary stent placement. Exclusion criteria were contraindications to the study drugs; indications for AC therapy; or cardiogenic shock, mechanical ventilation, or both before angioplasty.

Intervention

After successful stent placement, patients received heparin (partial thromboplastin time 80 to 100 s) and were then allocated to AP therapy (ticlopidine, 250 mg twice daily for 4 wks, n = 61) or AC therapy (phenprocoumon, n = 62). Heparin infusion was stopped after 12 hours in the AP group. The AC group received heparin for 5 to 10 days until stable oral anticoagulation was achieved. All patients received aspirin (100 mg twice daily) and were hospitalized for ≥ 14 days. Repeat angiography was done at 6 months.

Main outcome measures

Rates of early (≤ 30 d) and late (6 mo) cardiac and noncardiac clinical events, stent vessel occlusion, and restenosis (6 mo).

Main results

The rates of early clinical events and noncardiac events in the AP group were lower than those in the AC group (P = 0.005 and P = 0.03, respectively) (Table). AP therapy led to lower rates of stent vessel occlusion (P = 0.03) and hemorrhagic events (P = 0.007) than AC therapy. At 6 months, the AP group had a higher rate of survival without recurrent myocardial infarction (P = 0.03) and a lower rate of stent vessel occlusion (P = 0.02) than the AC group. Restenosis rates did not differ between groups.

Conclusion

Compared with anticoagulant therapy, antiplatelet therapy after successful coronary stent placement reduced the rate of clinical events and stent vessel occlusion.

Sources of funding: In part, Siemens Medical Systems; Scimed-Boston Scientific; Johnson and Johnson Interventional Systems.

For article reprint: Dr. A. Schömig, 1. Medizinische Klinik, Klinikum rechts der Isar, Ismaningerstrasse 22, 81675 Munich, Germany. FAX 49-89-4140-4900.


Table. Antiplatelet (AP) vs anticoagulant (AC) therapy*

Outcomes at 30 days AP EER AC CER RRR (95% CI) ARR |EER-CER| NNT (CI)
Clinical events 3% 21% 84% (42 to 96) 18% 6 (3 to 15)
Noncardiac events 2% 13% 87% (25 to 98) 11% 9 (5 to 39)

*Abbreviations defined in Glossary; RRR, ARR, NNT, and CI calculated from data in article.


Commentary

Stent placement is challenging balloon angioplasty as the preferred percutaneous revascularization strategy for coronary artery disease. Initially, the procedure was limited by a 3% to 5% risk for subacute stent thrombosis (1, 2). APs and ACs, including aspirin, dipyridamole, dextran, heparin, and warfarin, were given to prevent this complication but were associated with a 1-week hospital stay and a 7% to 13% risk for bleeding or vascular complications (1, 2).

2 observations have made stent placement the preferred strategy for many patients. First, Columbo and colleagues (3) showed the importance of high-pressure balloon inflation in the stent to assure full stent apposition with the arterial wall. Second, Schömig and colleagues (4) and others (5) subsequently showed that AP therapy with aspirin and ticlopidine reduced both cardiac events and hemorrhagic and vascular events compared with AC therapy with intravenous heparin and warfarin. Presently, stent placement is associated with a 1% subacute thrombosis rate and a 1% risk for serious bleeding or vascular complications. Length of hospital stay for stent placement is at least equivalent to that of balloon angioplasty, and both acute ischemic complications and restenosis rates are lower with stent placement than with balloon angioplasty.

In this study, Schömig and colleagues further describe treatment results in 123 patients, who, in the initial study (4), had myocardial infarction within 48 hours of intervention. Despite concerns about the thrombogenicity of the metal surface that was placed in a thrombus-containing arterial segment, AP therapy was again superior to AC therapy. Moreover, adverse clinical events and reocclusion rates of infarcted arteries were lower than those in the historical data for balloon angioplasty. This study suggests that stenting may tip the controversy between thrombolytic therapy and primary balloon angioplasty for acute myocardial in-farction in favor of angioplasty in settings where angioplasty is immediately available.

Eric R. Bates, MD
University of MichiganAnn Arbor, Michigan, USA


References

1. Fischman DL, Leon MB, Baim DS, et al. N Engl J Med. 1994;331:496-501.

2. Serruys PW, de Jaegere P, Kiemeneij F, et al. N Engl J Med. 1994;331:489-95.

3. Columbo A, Hall P, Nakamura S, et al. Circulation. 1995;91:1676-88.

4. Schömig A, Neumann F-J, Kastrati A, et al. N Engl J Med. 1996;334:1084-9.

5. Hall P, Nakamura S, Maielo L, et al. Circulation. 1996;93:215-22.