Results:
Between November 2010 and September 2017, 47 cardiac arrest patients
were initiated on ECMO at the time of active CPR for cardiac arrest.
Baseline characteristics for survivors and non-survivors are described
in Table 1. ECPR patients were more commonly male (n=33; 70.2%) with a
median age of 53 years. The majority of patients had underlying
cardiovascular disease, including 20 patients (42.6%) with known
cardiomyopathy and 27 (57.4%) with coronary artery disease.
Arrest and cannulation locations are described in Table 2. Forty-five
patients (95.7%) experienced an in-hospital cardiac arrest while two
patients experienced an out-of-hospital arrest but were cannulated in
the hospital while receiving CPR (4.3%). The most common locations for
both arrest and cannulation were the cardiac catherization lab and the
intensive care unit.
Arrest rhythms were either PEA (n=25; 53.2%) or pulseless VT/VF (n=22;
46.8%). Arrest etiologies included acute coronary syndromes (n=17;
36.2%), acute heart failure syndromes (n=10; 21.3%), pulmonary
embolism (n=7; 14.9%), primary arrhythmia (n=5; 10.6%), drug toxicity
or overdose (n=2; 4.3%), and other causes (n=6; 13%), including
tamponade (n=2), air embolism (n=1), perioperative hemorrhagic shock
(n=1), and sepsis/endocarditis (n=2) . In total, 4 patients (8.5%)
experienced arrest post-cardiotomy (from tamponade, PE, VT storm, and
VF), with 50% of these patients dying while on ECMO and the remaining
surviving to discharge.
Overall, 34 patients (72.3%) were adjudicated to have a primary cardiac
origin of their cardiac arrest. There was no significant association
found between etiology of arrest, arrest rhythm, or cardiac versus
non-cardiac origin of arrest and survival to discharge. Similarly, no
combination of arrest origin (cardiac or non-cardiac) and arrest rhythm
(PEA or VT/VF) was significantly associated with survival to discharge
[Table 3].
ECMO characteristics are described in Table 4. Almost all patients
underwent peripheral cannulation. Following cannulation, 22 (46.8%)
were underwent targeted temperature management, 19 (40.4%) had a
subsequent revascularization procedure, and 6 (12.8%) had a venting
ventricular assist device placed. Median time on ECMO support was 3.00
days.
ECMO-related complications included major bleeding (n=28; 59.6%), renal
replacement therapy (n=24; 51.1%), cerebrovascular accident (n=10;
21.3%), and limb ischemia (n=8; 17.0%) [Table 5].
Overall ECPR patient survival to hospital discharge was 25.5% (n=12).
Twenty-six patients died on ECMO (55.3%) while 9 patients (19.1%)
survived ECMO decannulation but died prior to discharge. The majority of
patients who survived to discharge experienced myocardial recovery
(n=10; 83%); one patient underwent orthotopic heart transplantation
(8.3%), one received a durable ventricular assist device (8.3%), and 2
required new dialysis at discharge (16.7%). Most survivors had a
favorable CPC score of 1 at discharge (n=9; 66.7%) [Table 6].
Median intensive care unit and hospital length of stay for survivors was
28.5 [IQR 13.50, 39.50] and 35.50 days [IQR 21.75, 49.50]
respectively. Causes of death in non-survivors are listed in Table 7.
In univariate analysis, characteristics associated with survival to
discharge include younger age (median 44.0 [IQR 45.00,64.00] in
survivors versus 60.00 in non-survivors [IQR 46.00, 6.65]; p 0.034)
and arrest location in the emergency department (33.3% of survivors
versus 2.9% of non-survivors; p=0.012). Arrest etiology of pulmonary
embolism approached but did not cross the pre-established threshold for
significance (33.3% of survivors versus 8.6% of non-survivors,
p=0.060).