To the Editor: The recommendation for managing acute ST-segment-elevation myocardial infarction with percutaneous coronary intervention (PCI) is that the door-to-balloon inflation time should be 90 minutes. However, it can be up to 120 minutes, depending on when patients present to the emergency department (ED) after the onset of their symptoms.1 In such cases, an alternative immediate reperfusion strategy — fibrinolysis — should be considered.

At first glance, a door-to-balloon time of 90 minutes seems readily achievable, but what if the patient presents after hours, or presents to a hospital without PCI facilities?

The time required to refer the patient for PCI, organise ambulance transport and call in cardiac catheterisation laboratory staff can be considerable.

In the PRAGUE-2 trial from the Czech Republic, the average door-to-balloon time was 97 minutes.2 The DANAMI-2 study from Denmark had a cohort of 27 080 patients and had door-to-balloon times of about 114 minutes for those patients transferred to another facility.3 The National Registry of Myocardial Infarction 4 investigators reported a median door-to-balloon time of 185 minutes for American patients transferred to centres capable of PCI, and a door-to-balloon time of less than 90 minutes for only 3% of patients.4

Doctors working in EDs without onsite access to PCI need to know the door-to-balloon times of the institutions to which they refer patients for PCI. Centres performing PCI may not be forthcoming with this information, as they have a vested interest in keeping their numbers up for PCI. Alternatively, this information may not be known to the clinician accepting the patient for PCI.

In addition, doctors in EDs who opt to transfer their patients have the burden of organising transport for potentially unstable patients who may develop lethal arrythmias.

As door-to-needle time for thrombolysis has become a clinical indicator for EDs, perhaps door-to-balloon times can be a clinical indicator for cardiac catheterisation laboratories.

Finally, it is important to note that in some patients requiring urgent coronary artery reperfusion, the first electrocardiogram (ECG) is not diagnostic, so a more pragmatic indicator would be diagnostic ECG-to-balloon time. This would require an enforcement of the current recommendations for an ECG to be performed and critically reviewed shortly after a patient presents with symptoms suggestive of an acute coronary syndrome.

In reply: We agree with the points highlighted by Weeraratne, and these have been broadly addressed within the new National Heart Foundation of Australia and Cardiac Society of Australia and New Zealand Guidelines for the management of acute coronary syndromes 2006.1

The guidelines emphasise the need for appropriate systems of care which are regionally based, have formal links with specialist centres, include appropriate monitoring, feedback and quality improvement components, and are sensitive to the cultural and personal beliefs and wishes of individual patients.

Clinicians do need to know the achievable door-to-balloon times for primary percutaneous coronary intervention within their local contexts, and if there is any doubt about the timely availability of this treatment for patients with ST-segment-elevation myocardial infarction, the guidelines recommend that fibrinolysis be given promptly.