Number of procedures performed - split by clinical presentation of patient
Patients need PCI for a variety of different reasons called ‘syndromes’ and these are called the ‘Indications for PCI’. The indications for PCI in each operator’s practice are shown. Below is an explanation of each of these indications.
Stable angina occurs when a coronary artery becomes progressively narrowed and blood supply to the heart muscle becomes restricted. People usually experience a tight constricting feeling across the chest which may be associated with breathlessness. It is brought on by physical exertion or stress. Patients with stable angina will have been admitted from home for a planned procedure and usually return home the same day or the following day.
Primary PCI (for ST Elevation Myocardial Infarction or STEMI)
Patients presenting with a complete blockage causing ST elevation on the ECG need immediate treatment. If the blockage persists the region of the heart muscle supplied by that artery will progressively die (myocardial necrosis). In the past patients were treated with a drug that dissolved the occlusive clot (thrombolysis), but now the majority are treated by PCI. This emergency treatment is called Primary PCI, and the number of these cases by each consultant (or hospital) is shown (in these data we have also included ‘facilitated PCI’ – where primary PCI is immediately preceded by treatment with certain other medications).
ACS (Non STEMI)
All other acute coronary syndromes (unstable angina and NSTEMI) are usually caused by a partial or intermittent blocked of the coronary artery and do not usually need to be treated immediately. Recommendations are that they are treated during the initial hospital presentation, preferably within 72 hours. These have been grouped together in this category, and labelled ‘ACS (non STEMI)’.
Shock (Patients in cardiogenic shock before the start of the PCI procedure)
In some patients, the damage caused to the heart muscle by a heart attack is so extensive that the pumping function of the heart is profoundly compromised. If the amount of blood pumped around the patient’s body falls too low, it may be insufficient to sustain the normal function of vital organs, and they begin to shut down (for example kidneys, brain and the liver). When this happens a patient is described as being in ‘cardiogenic shock’. The chances of a patient surviving this critical condition are low, even when the best possible care is provided by the cardiac team. Approximately a third to a half of all such patients will succumb. An operator who works in a hospital that sees a relatively large number of such patients will have a higher mortality irrespective of how skilled the teams are in treating such patients. These factors need to be taken into account when interpreting outcome data. The risk adjustment models attempt to correct for these differences, but all such mathematical methods have limitations (see below)
Ventilated Pre op (patients who have sustained out of hospital cardiac arrest)
Another group of patients whose mortality is high, are those whose hearts stop before they can be brought to hospital. They are said to have suffered an ‘out of hospital cardiac arrest’. While such patients often die before reaching hospital, some can be resuscitated by trained bystanders or paramedics. In this case they are usually brought into hospital by ambulance unconscious and attached to a machine to help them breathe (a ventilator). This group are described as ‘Ventilated Pre-Op’. Even if they are successfully brought to hospital the chance of survival remains poor at about 50%. It is also very difficult to predict survival at the time they arrive. For example it is not possible to know if they have already sustained irreversible brain damage (which is the organ most susceptible to damage at the time of cardiac arrest). If this is the case then even after a successful PCI to treat their heart attack, they may never regain consciousness. These cases are listed in the chart, but as there are no mathematical models yet developed to predict outcomes they have not been included in the assessment of risk adjusted outcome.
There are a few other less common reasons for performing PCI which are grouped here.
|List of abbreviations|
|ACS||Acute Coronary Syndrome|
|BCIS||British Cardiovascular Intervention Society|
|CABG||Coronary Artery Bypass Grafting|
|CHD||Coronary Heart Disease|
|MACCE||Major Adverse Cardiac and Cerebrovascular Event|
|NSTEMI||Non ST elevation Myocardial Infarction|
|PCI||Percutaneous Coronary intervention|
|STEMI||ST elevation Myocardial Infarction|