Should all patients with an acute myocardial infarction be referred for direct PTCA?

Emergency percutaneous coronary interventions for acute myocardial infarction with ST-segment elevation in a regional hospital: a quality control study

BACKGROUND

An invasive approach of acute myocardial infarction with ST-segment elevation (STEMI) with primary percutaneous coronary intervention (PCI) is currently considered as the most efficient revascularisation strategy and is performed around-the-clock in tertiary hospitals. The present study is aimed at investigating the short term outcome of primary PCI eligible patients after STEMI in a regional institution (CHCV, Sion) in comparison to a University Hospital (CHUV, Lausanne).

METHODS

From January the 1st to December the 31st 2002, all consecutive STEMI patients of both centres who had an emergency coronary arteriography were included in the analysis. Clinical and angiographic data were retrospectively collected. The primary end point was the combined incidence of in-hospital death, reinfarction, and target vessel revascularisation (TVR) at 7 days.

RESULTS

The analysis included 58 patients in the CHVC (60+/-13 years, 16% of whom were female) and 160 patients in the CHUV (63+/-12 years, 25% were female). Both populations were identical according to the severity of coronary artery disease and distribution of risk factors, except for smokers (55% in CHCV, 39% CHUV, p=0.04). Most of the patients were treated by PCI in both centres (80% CHCV versus 86% CHUV, p=NS). A low proportion in both groups underwent urgent surgical treatment (3.5% CHCV versus 5.5% CHUV, p=NS). At 7 days, adverse events free survival was not statistically different.

CONCLUSION

These results were expected because the CHCV fulfils the international guidelines criteria for performance of emergency angioplasty. Our study demonstrates that around-the-clock primary PCI for acute STEMI can safely be done in a regional hospital (CHCV Sion) providing there is strict adherence to all aspects of international guidelines.

Determining geographic areas and populations with timely access to cardiac catheterization facilities for acute myocardial infarction care in Alberta, Canada

Background

This study uses geographic information systems (GIS) as a tool to evaluate and visualize the general accessibility of areas within the province of Alberta (Canada) to cardiac catheterization facilities. Current American and European guidelines suggest performing catheterization within 90 minutes of the first medical contact. For this reason, this study evaluates the populated places that are within a 90 minute transfer time to a city with a catheterization facility. The three modes of transport considered in this study are ground ambulance, rotary wing air ambulance and fixed wing air ambulance.

Methods

Reference data from the Alberta Chart of Call were interpolated into continuous travel time surfaces. These continuous surfaces allowed for the delineation of isochrones: lines that connect areas of equal time. Using Dissemination Area (DA) centroids to represent the adult population, the population numbers were extracted from the isochrones using Statistics Canada census data.

Results

By extracting the adult population from within isochrones for each emergency transport mode analyzed, it was found that roughly 70% of the adult population of Alberta had access within 90 minutes to catheterization facilities by ground, roughly 66% of the adult population had access by rotary wing air ambulance and that no population had access within 90 minutes using the fixed wing air ambulance. An overall understanding of the nature of air vs. ground emergency travel was also uncovered; zones were revealed where the use of one mode would be faster than the others for reaching a facility.

Conclusion

Catheter intervention for acute myocardial infarction is a time sensitive procedure. This study revealed that although a relatively small area of the province had access within the 90 minute time constraint, this area represented a large proportion of the population. Within Alberta, fixed wing air ambulance is not an effective means of transporting patients to a catheterization facility within the 90 minute time frame, though it becomes advantageous as a means of transportation for larger distances when there is less urgency.