Background Clinical investigations of
shock in cardiac intensive care units (CICUs) have primarily focused on acute
myocardial infarction (AMI) complicated by
cardiogenic shock (AMICS). Few studies have evaluated the full spectrum of
shock in contemporary CICUs. Methods and Results The
Critical Care Cardiology Trials Network is a multicenter network of advanced CICUs in North America. Anytime between September 2017 and September 2018, each center (n=16) contributed a 2-month snap-shot of all consecutive medical admissions to the CICU. Data were submitted to the central coordinating center (TIMI Study Group, Boston, MA).
Shock was defined as sustained systolic blood pressure <90 mm Hg with end-organ dysfunction ascribed to the
hypotension.
Shock type was classified by site investigators as cardiogenic, distributive,
hypovolemic, or mixed. Among 3049 CICU admissions, 677 (22%) met clinical criteria for
shock.
Shock type was varied, with 66% assessed as
cardiogenic shock (CS), 7% as distributive, 3% as
hypovolemic, 20% as mixed, and 4% as unknown. Among patients with CS (n=450), 30% had AMICS, 18% had ischemic
cardiomyopathy without AMI, 28% had nonischemic
cardiomyopathy, and 17% had a cardiac cause other than primary myocardial dysfunction. Patients with mixed
shock had cardiovascular comorbidities similar to patients with CS. The median CICU stay was 4.0 days (interquartile range [IQR], 2.5-8.1 days) for AMICS, 4.3 days (IQR, 2.1-8.5 days) for CS not related to AMI, and 5.8 days (IQR, 2.9-10.0 days) for mixed
shock versus 1.9 days (IQR, 1.0-3.6) for patients without
shock ( P<0.01 for each). Median Sequential Organ Failure Assessment scores were higher in patients with mixed
shock (10; IQR, 6-13) versus AMICS (8; IQR, 5-11) or CS without AMI (7; IQR, 5-11; each P<0.01). In-hospital mortality rates were 36% (95% CI, 28%-45%), 31% (95% CI, 26%-36%), and 39% (95% CI, 31%-48%) in AMICS, CS without AMI, and mixed
shock, respectively. Conclusions The epidemiology of
shock in contemporary advanced CICUs is varied, and AMICS now represents less than one-third of all CS. Despite advanced
therapies, mortality in CS and mixed
shock remains high. Investigation of management strategies and new
therapies to treat
shock in the CICU should take this epidemiology into account.