Cardiogenic shock (CS) represents a high risk population that is at risk for both in-hospital
mortality and readmission following discharge. CS can be either left ventricular (LV) or
right ventricular (RV) or of biventricular (BiV) origin. Even in patients with CS treated
with an invasive approach (cardiac catheterization, angioplasty, and coronary bypass
surgery), in-hospital mortality approaches 50%. Other causes of CS mainly include severe
decline in underlying systolic function (from non-ischemic causes such as sepsis, stress, and
progression of systolic left ventricular dysfunction among others), arrhythmias, and
mechanical cardiac complications. Cardiogenic shock in the absence of acute myocardial
infarction (AMI) (non-AMI CS) is excluded from most studies including randomized trials and
remains largely understudied. For many years, the intra-aortic balloon pump was thought to be
helpful in improving outcomes in cardiogenic shock. However, the landmark randomized,
controlled IABP-SHOCK II trial, published in 2012, and concluded that the use of intra-aortic
balloon counter pulsation did not significantly reduce mortality in patients with cardiogenic
shock complicating acute myocardial infarction. This led investigators to search for
alternate temporary mechanical circulatory support systems that might prove effective in
reducing mortality in cardiogenic shock. One such system is the Impella 5.0 and Impella RP
devices. The Impella 5.0 pump in a temporary continuous flow pump approved for hemodynamic
support for left ventricular shock CS patient and the Impella RP for right ventricular shock.
The other system is the Tandem heart pump. The investigators utilize the Impella and the
tandem pump for AMI CS and non-ischemic CS. The device is implanted for bridge to recovery,
bridge to transplant and as a bridge to durable device. The investigators have discovered
that recovery rates following AMI shock are significantly improved with the Impellaand tandem
heart pumps however; identifying which patient recovers remains a mystery. Adequate
parameters do not exist.
Patients who we are unable to recover are transitioned to a durable continuous flow left
ventricular assist devices (CF-LVAD) which are an effective alternative to heart transplant,
but are not risk-free: among the other effects, right ventricle (RV) hemodynamics are
significantly altered by the LVAD implantation. In fact, RV failure occurs in 5% of patients
with implanted CF-LVADs, and leads to a 6-fold increase in the risk of death. Moreover, RV
failure is a major contributing factor in prolonged hospitalizations, and is associated with
a higher risk of bleeding, renal failure, and hypotension. Currently, predictors of RV
failure in patients undergoing LVAD implantation are based entirely on retrospective case
series, often evaluating cohorts of patients with outdated classes of pulsatile-flow
LVADs.Furthermore, right ventricular failure (RVF) still results as the major cause of
morbidity and mortality after LVAD implantation. Despite overall improved outcomes and lower
rates of RVF with the use of the newer, LVAD over pulsatile-flow devices, and development of
clinical prediction scores to facilitate preoperative identification of patients at risk for
RVF after implantation remains elusive. RVF occurs in 13% to 40% of continuous-flow device.
The ability to predict the development of RV failure post LVAD implantation would
significantly improve outcomes as these patients would either have planned RVAD implantation
or receive a total artificial heart implantation.
