Introduction
In the early 1960s, the creation of Cardiac Care Units (CCUs) led to a 50% reduction in the in-hospital mortality of acute myocardial infarction (AMI). Prompt application of closed chest cardiac resuscitation and external defibrillation -- then new technologies -- served to reduce the consequences of the event. Over the ensuing four decades, therapeutic advances in the treatment of AMI (e.g. prompt reperfusion strategies) have favorably altered its natural history, potentially obviating the need for CCU care. Since such care is expensive, identification of a low risk cohort of patients in whom this care is not necessary could allow substantial improvements in the cost of cardiac care.
Hypothesis
Existing risk models can be used to accurately identify low risk STEMI patients who do not require CCU care after primary PCI.
Methods
We performed a retrospective chart review of all STEMI cases from 2010 at Carolinas Medical Center. We then assessed them using the TIMI STEMI risk score and a risk assessment algorithm for uncomplicated STEMI developed at Brigham and Women's Hospital (BWH). The BWH STEMI Care Redesign defines low risk STEMI patients as those who are promptly revascularized via successful single vessel PCI with (1) no evidence of ongoing ischemia, (2) EF>40%, (3) absence of CHF, hemodynamic or electrical instability, and (4) who are awake without need of respiratory support. Cost data (fixed and variable) from Quality Advisor™, a product by Premier, was abstracted for each STEMI case, examining specific resources used in CCU and non-CCU units.
Results
Among 310 consecutive STEMI patients, in-hospital mortality was 3.9%. The BWH risk score identified 46.4% of these patients as low-risk. Among these patients, in-hospital mortality was 0%. Only one of these 144 low-risk patients required subsequent CCU care. None required CPR or defibrillation after revascularization. The TIMI STEMI risk score <2 classified 26.1% of the patients as low-risk. Among these patients, in-hospital mortality was 0%. However, 3.7% of these "low-risk" patients had ventricular arrhythmias or respiratory decompensation during or shortly after PCI. None of the 3.7% were classified as "low-risk" by the BWH model. CCU care added $723 in fixed costs and $340 in variable costs per hospital day.
Conclusion
The BWH model, but not the TIMI STEMI risk score, accurately predicted a sizable cohort of STEMI patients at very low risk of in-hospital death and complications. These patients may be appropriate for admission to non-CCU level care immediately following primary PCI. Doing so would be projected to yield a cost savings of >$1000 per patient.
Ambulatory Outpatient Management of patients with low risk febrile neutropaenia
