Real-world interventional outcomes for cardiogenic shock complicating acute myocardial infarction

Acute myocardial infarction with cardiogenic shock (AMICS) carries high mortality and remains a major concern. This concern drives use of interventions with marginal benefit and some evidence of harm. The configuration of hospital care and allocation of interventions for AMICS in our health system created a natural experiment to analyze interventional outcomes for patients with AMICS.

To compare clinical outcomes among AMICS patients treated with mechanical circulatory support (MCS) using a micro-axial left ventricular assist device and intra-aortic balloon counter-pulsation (IABP).

In this observational study in a large health system, we used clinical registry data augmented with data from other sources to analyze 30-day and 180-day mortality as well as complications including major bleeding, and access site injury.

Of 505 patients with AMICS, 73 were treated with MCS and 160 with IABP. Baseline characteristics were similar between treatment groups except infarct location. Multivariable logistic regression showed that MCS was associated with 1.92 (CI = 1.10-3.37) times higher 30-day mortality risk and 2.03 (CI = 1.17-3.57) times higher 180-day mortality risk. In MCS-inclined hospitals as compared with IABP-inclined hospitals, patients had significantly higher 180-day mortality (45.3 % versus 33.9 %, p = 0.017), and bleeding rates (15.1 % versus 1.3 %, p < 0.001), with trends toward higher 30-day mortality (41.4 % versus 32.6 %, p = 0.064) and access site injury (4.7 % versus 1.3 %, p = 0.063).

In this real-world setting, MCS use for AMICS was associated with higher complication rates. Before using this device for AMICS, clinicians should consider tight selection criteria to minimize harm and maximize overall benefit.