Long-Distance Transfer for PCI Safe and Feasible

MINNEAPOLIS, Aug. 2 -- Myocardial infarction patients can be transported quickly and safely for percutaneous intervention at facilities more than 200 miles away, investigators in a model transfer program have found.

Researchers at the Minneapolis Heart Institute developed a standardized treatment system for patients with ST-elevation MI (STEMI) that resulted in an in-hospital mortality of 4.2% and a median hospital stay of three days, according to their report in the Aug. 2 issue of Circulation.

The system was used with 1,345 patients, including 1,048 who were transferred from hospitals as far as 210 miles away.

"A standardized treatment approach to STEMI in the United States has the potential to provide the optimal treatment (primary PCI) to the greatest number of patients, which will translate into improvement in the long-term outcome of STEMI patients," concluded Timothy D. Henry, M.D., and colleagues.

They noted that, in the U.S., the median first door-to-balloon time for primary percutaneous intervention is 180 minutes, and fewer than 5% of patients are treated within the 90-minute window recommended by the American Heart Association and the American College of Cardiology.

Such data has fueled the belief that a transfer strategy for percutaneous intervention in STEMI is impractical, the authors said.

Believing otherwise, Dr. Henry and colleagues developed a regional transfer protocol involving 30 community hospitals in Minnesota. The protocol was developed in accordance with AHA/ACC guidelines. Area physicians representing cardiovascular, emergency medicine, and primary care specialties provided input.

Key components of the protocol included:

• Collaboration between the tertiary care center where percutaneous intervention would be performed and the referral hospitals to emphasize ideal patient care.
• Diagnosis of STEMI by the emergency physician, who activated the protocol with a single phone call.
• Standardized treatment protocol based on AHA/ACC guidelines with preprinted standing orders.
• Coordinated hospital-specific transfer plan.
• Admission directly to the cath lab at the tertiary care center.
• Extensive initial training with comprehensive feedback and quality assurance that meets accepted criteria for STEMI.

After a trial run with a pilot program involving a single community hospital, the protocol was put in place in five hospitals in March 2003. Since that time, the number of participating hospitals has grown to 30, 11 of them within 60 miles of the Minneapolis Heart Institute (zone 1) and 19 from 60 to 210 miles away (zone 2).

The referring hospitals ranged in size from 10 to 162 beds. None had 24-hour cardiovascular consultation on site.

The study included patients with STEMI or new left bundle-branch block and symptom onset of 24 hours or less.

The 1,345 patients included in the data analysis consisted of 297 who presented directly to the tertiary care center, 627 transferred from zone 1 hospitals, and 421 from zone 2 hospitals. Many of the patients had high-risk characteristics:

• Age 80+ (14.6%)
• Cardiogenic shock (12.3%)
• Pre-PCI cardiac arrest (10.8%)
• Pre-PCI mechanical ventilation (6.9%)

Door-to-balloon times of <90 minutes were registered for 40% of patients transported from zone 1 hospitals and 10% of those from zone 2 facilities, compared with 80% of patients who were seen initially at the tertiary care facility.

Times less than <120 minutes were registered for 80% of those from zone 1 facilities and 40% of patients from zone 2 compared with more than 90% of those who went directly to the tertiary care center

The vast majority of patients from both zone 1 and zone 2 hospitals (70.5%) were transported to the tertiary care facility via helicopter.

Percutaneous intervention was attempted in 80.3% of the patients (N=1,072) and was successful in 99.3% of attempts, most of which included stent placement. An additional 48 patients had open heart surgery without PCI (coronary bypass graft surgery in 45 of the cases).

The 30-day mortality for all patients was 4.9%, and one-year mortality was 7.2%. Among patients undergoing PCI, mortality was 3.5% in hospital, 4.1% at 30 days, and 6.4% at one year. Exclusion of patients with cardiogenic shock resulted in mortality of 0.9% in hospital, 1.4% at 30 days, and 3.3% at one year.

Mortality data did not differ among patients who presented directly to the tertiary care center or those who were transferred from zone 1 or zone 2 hospitals.

"Our experience demonstrates that a regional care system for STEMI, anchored by a timely PCI strategy, is feasible in the United States, yields outcomes similar to a PCI center, and therefore has the ability to provide the most effective therapy for STEMI to a large segment of the population," the authors concluded.