Stent Primary Angioplasty in MI - STENT PAMI

Description:

Stenting vs PTCA in acute MI

Hypothesis:

Stenting would reduce acute and long term adverse events.

Study Design

Study Design:

Patients Screened: 1458
Patients Enrolled: 900
NYHA Class: Not reported
Mean Follow Up: 6.0.-6.5 months
Mean Patient Age: >18
Female: 25%
Mean Ejection Fraction: average 48%

Patient Populations:

Acute MI with symptom onset <12 hours and with culprit vessel suitable for coronary stenting

Exclusions:

Prior administration of thrombolytic agents for the index infarction, current use of warfarin, stroke in prior month, renal failure, cardiogenic shock, life expectancy <1 year, childbearing potential (unless recent pregnancy test negative), and known contraindications to aspirin, heparin, or ticlopidine

Primary Endpoints:

6-month incidence of death, reinfarction, and disabling stroke, or target vessel revascularization secondary to ischemia

Secondary Endpoints:

Mean luminal diameter, TIMI flow grade, all-cause mortality

Drug/Procedures Used:

Balloon angioplasty or heparin-coated Palmaz-Schatz stenting

Principal Findings:

Acute procedural success rates were >99% in both groups. The postprocedural TIMI grade 3 flow rates were 89.4% in the angioplasty group and and 92.7% in the stent group (p=0.10). At 6 months, the stent group had a larger mean luminal diameter (2.56mm vs 2.12mm, p<0.001) and lower restenosis rate (20.3% vs. 33.5%, P<0.001). Stenting was associated with showed a trend toward fewer primary composite end point events at 30 days (death, MI, disabling stroke, ischemia-driven TVR; 4.6% vs. 5.8%, p=0.46) and a significant reduction at 6 months (12.4% vs. 20.1%). The stent group also had significantly lower 6-month rates of total TVR (12.8% vs. 21.4%); bleeding rates were similar. Among patients with an occluded artery at the start of the PCI, 6 month mortality was higher among stented patients (6.1% for stent vs 2.0% for PTCA).

Interpretation:

In patients with ST segment elevation acute MI, routine implantation of a coronary stent was associated with a reduction in target vessel revascularization due to ischemia. In this trial, stenting of a closed artery was associated with a higher mortality rate at 30 days and 6 months (see Lansky reference below). the higher mortality rates among stented patients is troubling. It should be noted that the use of GP 2b3a inhibitors was infrequent in the trial, rigid early generation stents were used, high pressure deployment was in vogue during this time as was the tendency to oversize the stent. Many of these practice patterns have now changed, and the mortality differential should be re-evaluated in light of this.

References:

N Engl J Med 1999; 341: 1949-56. Lansky AJ, et al. J Am Coll Cardiol. 1999;33 (suppl A):368A.

Keywords: Myocardial Infarction, Stroke, Heparin, Angioplasty, Balloon, Coronary, Stents


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