DEFER-STEMI: Holding Off Stenting for Several Hours Improves Outcomes

SAN FRANCISCO, CA—A strategy of deferred stenting reduces no-reflow and thrombotic events compared with immediate stenting in select patients with ST-segment elevation myocardial infarction (STEMI), according to a study presented March 9, 2013, at the American College of Cardiology/i2 Scientific Session.

For the single-center all-comers DEFER-STEMI trial, researchers led by Colin Berry, MD, PhD, of the University of Glasgow (Glasgow, United Kingdom), studied 101 STEMI patients who underwent initial reperfusion with aspiration thrombectomy and/or balloon angioplasty such that TIMI 3 flow was established. Patients were then randomized to immediate (n = 49) or deferred stenting (n = 52).

Advantages Seen for Deferral

The median time to deferred stenting was 9 hours (range, 6-12). Overall, the incidence of no reflow or slow flow, the primary endpoint, was significantly lower in the deferred stenting group compared with those who underwent usual care with immediate stenting. The same was true for intra-procedural thrombotic events (development of new or worsening thrombus, abrupt vessel closure, no reflow, slow reflow, distal embolization or stent thrombosis) and the individual component endpoint of no reflow (TIMI 0/1; table 1).

Table 1. Primary Endpoints



Immediate Stenting
(n = 49)

Deferred Stenting
(n = 52)

P Value

No Reflow/Slow Flow (TIMI < 3)




Intra-procedural Thrombotic Events



< 0.0001

No Reflow (TIMI 0/1)




At 2 days post MI, the deferred stenting group also showed a trend toward a lower rate of microvascular obstruction and lower median infarct size on MRI (table 2).

Table 2. MRI Results



Immediate Stenting
(n = 49)

Deferred Stenting
(n = 52)

P Value

Microvascular Obstruction




Infarct Size




Two patients experienced early recurrent ST-elevation within 6 hours. In one of these cases, analysis suggested the patient may not have adequately met eligibility criteria.

Potentially Transferrable to Clinical Practice

“We’re very excited about these results,” Dr. Berry said, adding that the full range of angiographic data were consistently in favor of the deferred stenting strategy.

Currently, no evidence-based preventative treatments exist for deterrence of no reflow. Dr. Berry said the strategy offers anovel, pragmatic preventative intervention for no reflow and is potentially transferrable into clinical practice.”

He added that the safety and cost-effectiveness of the strategy merits further prospective assessment in a multicenter trial. Theoretically, delaying stenting would be likely to increase costs associated with adjunctive anticoagulation, repeated catheterization, and extended hospital stay.

Session co-moderator Gary S. Mintz, MD, of the Cardiovascular Research Foundation, (New York, NY), questioned Dr. Berry about the mechanism behind deferred stenting. According to Dr. Berry, the reduction in thrombus provides a benefit in that “all the problems that give rise to microvascular thrombosis… are less at that time.”

Dr. Mintz also pointed out that according to the most recent data from the National Cardiovascular Data Registry, the incidence of no reflow in treated STEMI patients was very low.

“There is a pathologic link between flow reduction during the procedure and microvascular obstruction. We believe the problem is common,” Dr. Berry said. “At the microvascular level we think there are opportunities for improvement and this strategy I believe has significant potential in that regard.”

Note: Several study co-authors are faculty members of the Cardiovascular Research Foundation, which owns and operates TCTMD. Dr. Mintz serves as Medical Director and Editor-in-Chief of TCTMD.




Source:Berry C. DEFER STEMI: A randomised trial of deferred vs. immediate stenting to prevent no-reflow in acute STEMI. Presented at: American College of Cardiology Annual Scientific Session; March 9, 2013; San Francisco, CA.





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  • The study was funded by the British Heart Foundation
  • Dr. Berry reports no relevant conflicts of interest.
  • Dr. Mintz reports receiving consulting fees/honoraria from Boston Scientific, Volcano, and Lightlab, and serving on the speaker’s bureau for Pfizer.

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