Musa A Sharkawi (Department of Cardiovascular Medicine, Hartford Hospital, Hartford, USA) and others report in Catheterization and Cardiovascular Interventions that the CADILLAC risk score could be used to determine which patients with ST-segment elevation myocardial infarction (STEMI) are at low risk for events after percutaneous coronary intervention (PCI) and, therefore, could be discharged from hospital before the recommended three days.
The authors report that the acute management of STEMI “typically involves immediate reperfusion followed by a period of observation and medication titration”, adding “much of the therapy is ‘front-loaded’ during the hospitalisation, and in uncomplicated cases, the benefit of prolonged observation is unclear”. Furthermore, they note that the current recommendation that low-risk patients can be discharged after 72 hours is based on data for fibrinolysis and “the risk of discharging low-risk patients following primary PCI earlier than 72 hours is not known”.
Therefore, Sharkawi et al retrospectively grouped, using the CADILLAC risk score, STEMI patients who underwent primary PCI over a two-year period into “low risk” or “intermediate to high risk” and then compared groups to assess adverse outcomes at day three or later. “The CADILLAC risk score assigns a point value to each of seven prognostic variables,” the authors explain. These variables include age >65 years, ejection fraction <40%, and final TIMI flow two or three.
Of the 228 patients in the study, 123 were considered to be low risk and 105 were considered to be intermediate to high risk. Low risk patients, according to Sharkawi et al, were more likely to be male, less likely to have diabetes, and were less likely to have prior heart failure. The median length of stay in both groups was three days, but the mean length of day was shorter in the low-risk group: 2.99±1 vs. 3.77±2.245 days (p<0.01). Furthermore, low-risk patients were less likely to die within one year: 0% vs. 4.8% for the intermediate to high risk group (p=0.02).
The authors report: “There were no cardiovascular events on the third day or later of hospitalisation in the low-risk group. There was a significantly lower event rate on day three or later patients with a low CADILLAC risk score compared to those with an intermediate to high-risk score (0% vs. 11.42%; p=0.0002).” They add in a secondary analysis, low-risk patients were significantly less likely to have cardiovascular event during the first 24 hours of hospitalisation: 3.25% vs. 13.3% for intermediate to high risk (p=0.006).
According to Sharkawi et al, their results support the use of CADILLAC risk score to identify low risk patients “in whom an early discharge is likely to be safe”. Furthermore, they note the European Society of Cardiology (ESC) guidelines suggest “at least a 24-hour period of monitoring” in a coronary care unit following reperfusion but comment: “Our findings, which are consistent with findings of the PAM II trial, suggest omission of the critical care observation period following successfully primary PCI for STEMI is feasible for low-risk patients in certain institutions”.
“Of patients with STEMI managed with primary PCI, low-risk patients identified using the CADILLAC risk score had no adverse events on the third day of hospitalisation or later, suggesting that an early discharge after two days midnights is safe in properly selected patients,” the authors conclude.
Sharkawi told Cardiovascular News: “Institutions with dedicated cardiac step-down units where staff are carefully educated and trained in post-STEMI care and complications may consider this. This would probably be most feasible and safest at medical centres with a high enough volume of sick cardiac patients. We would re-emphasise the need for careful and thoughtful patient selection for either early discharge or exclusion of critical care monitoring for STEMI patients after successful PCI.”