Introduction With the drive to reduce cost and length of hospital stay, there is a need for risk scoring tools to identify patients who can be discharged early. One tool that has been validated in primary percutaneous coronary intervention (PPCI) is the Zwolle Risk Score (see Abstract 117 Table 1). Independent predictors of 30-day mortality included in the score are age, anterior infarct, Killip class, ischaemia time, TIMI flow and the presence of triple vessel disease.
A score of ≤3 out of 16 has been shown to confer low risk, with one large study showing mortality of 0.1% at 2 days and 0.2% between 3 and 10 days. Proponents of the Zwolle risk score advocate early discharge (at 48 h) in patients with a score of ≤3, however this has not yet been universally accepted in the UK. We sought to review whether implementation of this risk score would identify a significant number of patients for early discharge without compromising patient care. We also analysed projected savings in bed days and cost.
Method We retrospectively evaluated 100 consecutive patients taken to the catheter laboratory as part of the PPCI pathway since starting our 24 h service. Data were collected from a dedicated angioplasty database and cross-referenced with the MINAP database and case notes. Baseline patient characteristics were collected and individual risk scores were calculated using the Zwolle criteria. Patients were considered as being potentially suitable for early discharge if they had a score of ≤3. Outcomes at 30 days were documented.
Results Eighty-one out of the 100 patients admitted via the PPCI pathway went on to have coronary intervention. The mean age of the cohort was 67+/−13 years; 57 male (70.4%), 11 diabetic (13.6%), 27 hypertensive (33.3%), 34 hypercholesterolaemic (42%) and 28 smokers (34.6%). The median Zwolle score was 3 (IQR 2–4), with 55 patients (67.9%) being potentially eligible for early discharge by having a score of ≤3. Of these, 22 (40%) were actually discharged at 48 h, with the rest staying a total of 55 bed days. A bed day at University Hospital is currently estimated to cost £110. By applying the Zwolle criteria for early discharge in all eligible patients, £6050 could have been saved. All complications required re-admission (n=5) and occurred at a mean of 9.2 days after intervention. The earliest complication was at 3 days for stent thrombosis secondary to clopidogrel omission. The remaining complications occurred after 9 days (femoral complication n=2, chest pain n=2).
Conclusion The use of the Zwolle risk score in patients undergoing PPCI identifies a significant proportion of patients who would be candidates for early discharge. This does not appear to compromise patient safety and the widespread implementation of this policy in the NHS has the potential for both substantial cost savings and reduced length of inpatient stay.
- primary angioplasty
- Zwolle risk score
- cost saving