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Drip and Ship: The Case for Facilitated Percutaneous Coronary Intervention

Topic: Interventional Cardiology
Interviewee: Howard C. Herrmann, MD, FACC
Interviewer: Raymond J. Gibbons, MD, FACC

The Challenge

Primary angioplasty is widely viewed in the United States as the therapy of choice for reperfusion in acute myocardial infarction (MI), but time is a critical factor in optimizing outcome with any reperfusion therapy.1 Considering that percutaneous coronary intervention (PCI) programs are available at less than 25% of acute-care hospitals in the U.S.,2 there may be lengthy delays in getting a patient transferred to a hospital for primary PCI.

In other countries, as well as in many rural areas of the United States, these delays have led to the adoption of so-called facilitated PCI. This approach uses early pharmacologic reperfusion followed by later catheterization and revascularization, if necessary. According to Howard C. Herrmann, MD, FACC, this approach never received the widespread acceptance in the U.S. due, at least in part, to early data suggesting potential increased risk associated with combining the two therapies. Moreover, as PCI and stenting evolved and as more patients were considered candidates for primary angioplasty, there was limited support for advancing what many considered to be “yesterday’s” reperfusion strategy.

However, new data and large meta-analyses are suggesting that facilitated angioplasty deserves a second look.

The Data

At first glance, the data certainly underscore the value of primary angioplasty. A meta-analysis, published in Lancet in 2003, reviewed data from 23 trials comparing primary angioplasty to intravenous thrombolytic therapy. It concluded that PCI is more effective in reducing mortality by 2 percentage points in patients with ST-segment elevation MI (STEMI). The findings favored angioplasty based on overall short-term mortality (7% vs. 9%, p=0.0002), nonfatal reinfarction (3% vs. 7%, p<0.0001), and stroke (1% vs. 2%, p=0.0004). The advantages associated with primary angioplasty were sustained during long-term follow-up, and were independent of factors like the type of thrombolytic agent used.3 (Slide 1)

However, when evaluating the findings of randomized trials, such as those included in the Lancet study, door-to-balloon times were very short, usually well within 3 hours of symptom onset. In real-world circumstances, said Dr. Herrmann, it is often difficult to achieve these same optimal times to reperfusion. The data also support the fact that delays weaken the benefit of primary angioplasty compared to pharmacologic reperfusion.

The importance of prompt treatment was described in a recent study of 1,791 patients with acute STEMI, who were treated with primary angioplasty. A total of 5.8% of these patients had died at 1-year follow-up. After adjusting for confounding factors such as age, gender, diabetes and prior revascularization, the study concluded that each 30 minutes of delay increased the risk of 1-year mortality by 7.5%.4

The issue of delays in PCI – specifically those associated with the interhospital transfer of patients – was quantified by Nallamothu, et al.5 Real-world transfer times were obtained using data from the National Registry of Myocardial Infarction (the NRMI-3 and -4 cohorts). Among 4,278 STEMI patients transferred for primary PCI, the median total door-to-balloon time was 180 minutes. Only 4.2% of patients were treated within 90 minutes, which is the time frame recommended by national quality guidelines; only 15% were treated within 120 minutes. The researchers concluded that “transfer for primary PCI in the United States is presently failing to achieve established benchmarks in the majority of STEMI patients.”6,7

Findings like these raise the issue of whether reperfusion therapy should be administered before or during transport to the catheterization laboratory. A number of trials are underway to determine which pharmacologic therapy may be preferred in this setting or whether the optimal approach is to wait until angiography can be performed. An international trial, FINESSE (Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events), is farther along than other studies designed to examine these questions, with more than half of its 3,000 projected patients with acute MI currently enrolled in this prospective, multicenter, randomized, double-blind, placebo-controlled trial. FINESSE has three treatment arms, comparing the efficacy and safety of (a) facilitated PCI with reduced-dose reteplase plus abciximab bolus doses given in the emergency department (ED), (b) facilitated PCI with an abciximab bolus injection administered in the ED, and (c) primary PCI with abciximab given in the cardiac catheterization lab just prior to the procedure.1 (Slide 2)

Interpretation

According to Dr. Herrmann, “Early trials in the late 1980s and early 1990s examined the concept of giving a lytic agent and then going into the cath lab. And uniformly, no matter what lytic agent was given or what endpoint was looked at, angioplasty after an early lytic agent had a worse outcome than delayed angioplasty – defined as angioplasty 24 hours, 48 hours, or even 7 days later.” But, he added, because the action of thrombolytics can lead to potent platelet activation, more recent trials are using the addition of a glycoprotein IIb/IIIa receptor agonist (such as abciximab) that inhibits platelet aggregation. “Some of the early bad outcomes may have been related to reocclusion due to platelet activation,” he said, suggesting that outcomes could be improved by using newer, more potent antiplatelet agents.

Technological advances in PCI also may improve outcomes associated with facilitated angioplasty. Better balloons, wires, and visualization techniques may reduce risk. In the past, said Dr. Herrmann, when angioplasty would be performed after administering a thrombolytic agent, the angioplasty itself might damage the arterial walls, increasing bleeding that would compromise outcomes. “But we now have intracoronary stents, which are very good at sealing dissections,” thus leading to better results.

Facilitated PCI, according to Dr. Herrmann, also has the potential benefit of improving patient stability during interventions. Patients with open arteries have less shock and more favorable intra-arterial blood pressure. Technical success during intervention may be more likely due to a less hectic procedure, and better distal vessel visualization.

Because studies like FINESSE are still ongoing, definitive answers about optimal therapeutic approaches are not yet available. Nevertheless, the data are certainly encouraging and provide options for certain patients, such as the high-risk patient “with a large MI or a patient heading toward early cardiogenic shock.” If there is a delay in estimated door-to-balloon time, early thrombolysis or fibrinolysis may be an option.

Second Opinion

Raymond J. Gibbons, MD: Time is very important in terms of outcomes with reperfusion therapy. Although facilitated PCI is an attractive concept, the data are not yet available to prove that it really works. In the meantime, all of us ought to do everything possible to reduce delays in transfer, and make sure that patients are reperfused as soon as possible.

Guidelines

Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction—executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1999 guidelines for the management of patients with acute myocardial infarction). Circulation. 2004;110:588-636.

Van de Werf F, Ardissino D, Betriu, et al. Management of acute myocardial infarction in patients presenting with ST-segment elevation; the Task Force on the Management of Acute Myocardial Infarction of the European Society of Cardiology. Eur Heart J 2003;24:28-66.

References

  1. Ellis SG, Armstrong P, Betriu A, et al. Facilitated percutaneous coronary intervention versus primary percutaneous coronary intervention: design and rationale of the Facilitated Intervention with Enhanced Reperfusion Speed to Stop Events (FINESSE) trial. Am Heart J 2004;147:-
  2. American Hospital Association. The Annual Survey of Hospitals Database: Documentation for 2000 Data. 2000;:-
  3. Keeley EC, Boura JA, Grines CL. Primary angioplasty versus intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review of 23 randomized trials. Lancet 2003;361:13-20
  4. De Luca G, Suryapranata H, Ottervanger JP, Antman EM. Time delay to treatment and mortality in primary angioplasty for acute myocardial infarction. Circulation 2005;111:718-720
  5. Nallamothu BK, Bates ER, Herrin J, et al. Times to treatment in transfer patients undergoing primary percutaneous coronary intervention in the United States. NRMI 2005;111:761-767
  6. Antman EM, Anbe DT, Armstrong PW, et al. ACC/AHA guidelines for the management of patients with acute myocardial infarction—executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines Circulation 2004;110:588-636
  7. Van de Werf F, Ardissino D, Betriu, et al. Management of acute myocardial infarction in patients presenting with ST-segment elevation; the Task Force on the Management of Acute Myocardial Infarction of the European Society of Cardiology. Eur Heart J 2003;24:28-66

Fuente: Cardiosource

Ultima actualizacion: 07 DE ABRIL DE 2005

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