The investigators intend to study how baseline arterial compliance (as defined by stroke volume/pulse pressure) influences the clinical success of intraaortic balloon counterpulsation (IABC) in patients with cardiogenic shock (CS). The investigators aim to compare clinical outcomes in CS patients requiring IABC with normal compliance versus low compliance. The study will enroll patients undergoing IABC that are clinically indicated. Baseline hemodynamic measurements will be obtained and then patients would be stratified based on their compliance. Post IABC, serial hemodynamic measurements will be obtained and compared between groups. Patients will continue to be followed longitudinally until the IABC has been discontinued for any reason. The proposed study will yield results that will aid in developing a larger clinical trial and ultimately assist clinicians in determining if IABC is appropriate therapy for patients in cardiogenic shock.

This study will focus on patients in cardiogenic shock (CS) that will be undergoing clinically indicated intraaortic balloon counterpulsation (IABC) insertion and right heart catheterization. Prior to IABC insertion a patient will have their clinically indicated right heart catheterization. The investigators will record these baseline hemodynamic parameters, including (but not limited to) stroke volume and arterial pulse pressure.

After IABC insertion is completed, repeat hemodynamic measurements will be obtained approximately 30 minutes later. Repeat hemodynamic measurements will be recorded at approximately 3-6 hours following the procedure, and 24 hours following the procedure. The act of recording hemodynamic measurements is part of the usual clinical management of patients with IABC.

The patients will continue be followed longitudinally until their IABC course has completed, either due to resolution of CS, exchange for a separate device, heart transplantation, durable Left Ventricular Assist Device (LVAD) implant, or patient death.

The investigators hypothesize that patients with low arterial compliance will have greater improvements in cardiac output and cardiac filling pressures compared to patients with normal compliance. The specific aims are to (1) compare hemodynamic changes with IABC in cardiogenic shock patients with low compliance vs those with normal compliance and (2) to determine a cutoff value of compliance that can be used for future larger clinical trials.

The proposed study will yield results that will aid in developing a larger clinical trial and ultimately assist clinicians in determining if IABC is appropriate therapy for patients in cardiogenic shock.

Inclusion Criteria:

• Age ≥18 years old
• Cardiogenic shock
• Undergoing Intra-aortic Balloon Counterpulsation (IABC) as part of clinical care
• Able to provide consent or have power of attorney or next of kin provide consent

Exclusion Criteria:

• Age <18 years old
• Unable to consent or does not have power of attorney or next of kin to consent

Cardiogenic shock patients undergoing Intra-aortic Balloon Counterpulsation