The Subcutaneous Heparin and Angioplasty Restenosis Prevention (SHARP) trial. Results of a Multicentre Randomized Trial Investigating the Effects of High Dose Unfractionated Heparin on Angiographic Restenosis and Clinical Outcome - SHARP Prevention

Description:

The goal of this study was to assess the safety and efficacy of high-dose subcutaneous unfractionated heparin in the prevention of restenosis among patients after successful percutaneous transluminal coronary angioplasty (PTCA).

Hypothesis:

Experimental animal data suggested that heparin may influence changes in vascular smooth muscle cells that lead to restenosis. It was therefore hypothesized that high-dose subcutaneous unfractionated heparin therapy for four months after successful PTCA would be associated with a decrease in the rate of restenosis.

Study Design

Patients Enrolled: 339
Mean Follow Up: Four months
Mean Patient Age: Mean age 56 years
Female: 19

Patient Populations:

Patients were eligible to participate in this study if they had symptomatic coronary stenoses, which were treated by successful PTCA.

Exclusions:

Patients were excluded if they had restenotic lesions, lesions in conduits, or chronic occlusions.

Primary Endpoints:

The primary endpoint of this trial was the within-patient change in MLD, as assessed by four-month quantitative coronary angiography.

Secondary Endpoints:

The secondary endpoints of this study were the occurrence of death, fatal myocardial infarction, the need for CABG, the need for repeat PTCA, and presence and severity of angina at follow-up.

Drug/Procedures Used:

Eligible patients were randomized to receive either 12,500 IU of subcutaneous unfractionated heparin twice daily for four months or no heparin after successful PTCA.

Concomitant Medications:

All patients were anticoagulated with intravenous unfractionated heparin prior to and for up to 24 hours after their procedure. Additionally, all patients were discharged on aspirin 75 to 300 mg daily.

Principal Findings:

At four-month angiographic follow-up, there were no significant differences between the no heparin and the heparin groups in terms of loss of minimal lumen diameter (MLD) (-0.55 ± 0.58 mm vs. -0.43 ± 0.59 mm; p=0.07) or restenosis (51% vs. 41%; p=0.09). Additionally, there were no significant differences in the incidence of death, fatal myocardial infarction, coronary artery bypass surgery (CABG), or repeat PTCA.

Interpretation:

Among patients with symptomatic coronary artery disease who underwent a successful PTCA for a significant stenosis in one or more coronary arteries, high-dose subcutaneous unfractionated heparin was not associated with a significant difference in the primary endpoint of within-patient change in MLD at four-month coronary angiography.

Additionally, there was no difference in the occurrence of clinical events or angina during the follow-up period. These findings suggest that long-term treatment with high-dose subcutaneous unfractionated heparin is not beneficial in clinical outcomes or the prevention of coronary restenosis after successful PTCA.

References:

Brack MJ, Ray S, Chauhan A, et al. The Subcutaneous Heparin and Angioplasty Restenosis Prevention (SHARP) trial. Results of a multicenter randomized trial investigating the effects of high dose unfractionated heparin on angiographic restenosis and clinical outcome. J Am Coll Cardiol 1995;26:947-54.

Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Coronary Restenosis, Coronary Angiography, Heparin, Constriction, Pathologic, Coronary Artery Bypass, Muscle, Smooth, Vascular, Angioplasty, Balloon, Coronary


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