Significance of Off-hours in Centralized Primary Percutaneous Coronary Intervention Network

Aim

To analyze the efficacy of a regionally organized primary percutaneous coronary intervention (PCI) network at the Heart Center, Semmelweis University Budapest, part of the “Budapest model,” and the factors that influence it.

Methods

In order to investigate the differences between regular and off-hours patient care in a 24-hour myocardial infarction primary care system, we included 1890 consecutive, unselected patients with ST-segment elevation myocardial infarction and followed them until at least one year. The follow-up was complete for all participants.

Results

The difference between regular hours and off-hours mortality was not significant after 30 days (8.6% vs 8.8%, respectively) or after 1 year (15.3% vs 14.7%, respectively). The rate of patients with re-infarction, frequency of re-intervention, and major adverse cardiac events, including death, re-infarction, re-intervention, and coronary artery bypass graft surgery, were similar in both patient groups. The time delay between the onset of chest pain and arrival to the clinic was 5.9 ± 5.8 hours (mean ± standard deviation)during regular hours and 5.2 ± 4.6 hours during off-hours (P = 0.235). Direct transport caused significant decrease in the 30-day and 1-year mortality independent of duty time (7.2% vs 9.9%, P = 0.027; 12.6% vs 16.7%, P = 0.028; respectively).

Conclusion

Centralized primary PCI network of the “Budapest model” achieved the same level of patient care during both off-hours and regular hours.The generally accepted treatment of acute ST elevation myocardial infarction (STEMI) within 12 hours is primary percutaneous coronary intervention (PCI). However, the outcome of PCI may be influenced by several factors, like annual number of procedures (1-4), experience of the operating physician, time delay to treatment (5-8), and organization level of myocardial infarction care (9-16). In case of organized primary PCI network, the most important factor that influences the clinical outcome is the time of the arrival to the PCI center. Patients treated during off-hours can have a higher incidence of failed operation procedure and consequently a worse prognosis than patients treated during regular hours (17-22).Assali et al (18) reported that the unadjusted mortality at 1 month was significantly higher in patients treated during the night than in those treated during the day (9.7% vs 3.1%) (18). Henriques et al (19) demonstrated that the admittance of patients between 8:00 am and 6:00 pm was associated with an angioplasty failure rate of 3.8%, compared with 6.9% between 6:00 pm and 08:00 am Thirty-day mortality was 1.9% in patients with hospital admission between 8:00 am and 6:00 pm, compared with 4.2% in patients with hospital admission between 6:00 pm and 8:00 am (19). A related study of 231 164 STEMI patients (20) showed that the 30-day mortality was significantly higher for patients admitted on weekends (12.9% vs 12.0%). A cohort study of 68 439 patients with STEMI (21) showed that these patients had substantially longer door-to-balloon times during off-hours (116.1 minutes) than during regular hours (94.8 minutes; difference, 21.3 minutes; 95% confidence interval, 20.5-22.2).There are only limited data about organized primary PCI networks in large European cities (11-13,23,24). Despite the fact that it has been shown that high-quality organization of the primary PCI network may improve the outcome (25,26), a well organized, 24-hour available “service” for every citizen is rarely available (11).Five years ago we established a centralized myocardial infarction primary care model for the Budapest region, called the “Budapest model” (16), in which all the patients from the region requiring reperfusion therapy are primarily transported for PCI. The model comprises 5 PCI centers that perform primary PCI care on weekdays during regular hours, while during off-hours 1 of the 5 centers is on duty and admits all the patients.The aim of our study was to analyze the efficacy of the primary PCI network in Budapest and central Hungary, and to study the differences between regular and off-hours patient care in a 24-hour myocardial infarction primary care system.