STEMI Patients Far From PCI Centers Fare Well With Pharmacoinvasive Strategy

Primary PCI is the preferred reperfusion method for STEMI, but in the real world, many patients live too far from PCI-capable hospitals to receive timely intervention. Reassuringly, a new study suggests that a strategy of fibrinolysis followed by later angiography is associated with similar clinical outcomes as immediate PCI, with the exception of higher bleeding rates. 

The results would appear to support efforts that have been made in recent years to implement regional STEMI programs that coordinate care between PCI-capable and non-PCI-capable hospitals.

According to the study authors, led by Mohammed K. Rashid, BHSC (University of Ottawa Heart Institute, Ontario, Canada), the findings “are encouraging for centers that do not have rapid access to a PCI center.”

To TCTMD, senior author Michel R. Le May, MD (University of Ottawa Heart Institute), said the results also demonstrate that coordinated STEMI care utilizing pharmacoinvasive therapy has the “opportunity bridge the gap between fibrinolysis alone and primary PCI.”

Bleeding the Only Trade-off

The researchers examined safety and efficacy outcomes over a 2-year period from 2009 to 2011 among Canadian STEMI patients who lived within approximately 55 miles of a PCI-capable hospital and received primary PCI (n = 980) or who lived further away and received a pharmacoinvasive strategy (n = 236). The latter strategy consisted of clopidogrel (300 mg if ≤ 75 years), heparin (12 U/kg/h), and tenecteplase, with subsequent transfer to a PCI-capable facility for angiography within 24 hours of presentation.

Compared with patients who underwent primary PCI, those who did not had shorter median time from onset of symptoms to arrival at first hospital (92 min vs 97 min; P = 0.03), but much longer median door-to-balloon times (305 min vs 95 min; P < 0.0001). Additionally, the time from onset of symptoms to balloon inflation was more than twice as long in the pharmacoinvasive group (415 min vs 204 min; P < 0.0001).

Overall, there were no differences between the pharmacoinvasive and primary PCI groups for the composite of in-hospital mortality, stroke, or reinfarction (6.4% vs 7.0%; P = 0.71). However, three patients in the pharmacoinvasive strategy had intracranial bleeds compared with none in the primary PCI group. Furthermore, multivariate analysis indicated that those in the pharmacoinvasive group were twice as likely to have a major bleed compared with those in the primary PCI group (P = 0.06).

“The results with our pharmacoinvasive strategy were close to what we see with primary PCI,” LeMay noted. He added that based on the bleeding signal, his group has proposed a change to their protocol that would reduce the tenecteplase bolus to a half dose for patients age 75 and older to decrease the chance of intracranial bleeding, “with some contingencies to try to get those patients to the cath lab fast because we would not expect that the reperfusion, in terms of TIMI flow, would be quite as good as full-dose tenecteplase.”

Many Being Denied ‘Companion Strategy’

In an editorial accompanying the study, Timothy D. Henry, MD (Cedars-Sinai Heart Institute, Los Angeles, CA), and Paul W. Armstrong, MD (University of Alberta, Edmonton, Canada), say the Canadian experience highlights some key remaining issues in the contemporary treatment of STEMI, including the preferred reperfusion strategy for STEMI patients with an expected delay > 120 minutes.

Much like the current study, the STREAM trial found no difference in the composite of death, shock, heart failure, and reinfarction at 30 days between fibrinolysis prior to transfer to a PCI-capable hospital and primary PCI. A later subanalysis of STREAM suggested the pharmacoinvasive strategy was actually superior to primary PCI in situations where treatment delays ranged from 55 minutes to more than 97 minutes, Henry and Armstrong note.

“Therefore, the available evidence currently supports a [pharmacoinvasive] strategy when there is a potential delay beyond 120 [minutes] or perhaps even a lesser delay,” they write. “Based on recent National Cardiovascular Data Registry data, most US patients with delays are being denied this opportunity.” This situation has persisted for over a decade, they add, despite intensive national campaigns and quality assurance programs aimed at shortening D2B time.

“The resulting suboptimal treatment for many such patients underscores the familiar adage that ‘one size does not fit all’ and highlights the need to elevate [pharmacoinvasive] therapy as a companion strategy to PCI,” the editorialists point out.

But Henry and Armstrong say questions remain regarding the ideal drug regimen for a pharmacoinvasive strategy, as well as the optimal timing of the invasive portion of the intervention.

“Standardization is a key part of this process, but it is feasible to do it,” Lemay told TCTMD. “STEMI systems can work very efficiently, but you put them together a piece at a time. You start slow and you grow them, and you standardize and simplify all aspects of your protocols and make sure that everyone involved is on board. There are many choices potentially that you may need to make because one size doesn’t fit all, and there is room for improvement, but the real problem is when people don’t know what they are supposed to do. From our experience, feedback from all members of the team is a big key to fine-tuning and modifying our system.”

 

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Sources:

 

• Rashid MK, Guron N, Bernick J, et al. Safety and efficacy of a pharmacoinvasive strategy in ST-segment elevation myocardial infarction: a patient population study comparing a pharmacoinvasive strategy with a primary percutaneous coronary intervention strategy within a regional system. J Am Coll Cardiol Intv. 2016;9:2014-2020. 
• Henry TD, Armstrong PW. The choice is reperfusion therapy: but which one? J Am Coll Cardiol Intv. 2016;9:2021-2023. 

 

Disclosures:

 

• LeMay, Henry, and Armstrong report no relevant conflicts of interest. 

 

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• Coordinated STEMI Care Results in More Rapid Diagnosis and Treatment
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• RACE: Regional STEMI Care System Improves Time to Reperfusion, Survival