Right Heart Failure and the Impella RP® with SmartAssist® Heart Pump

What are the causes and incidence of right heart failure?

The causes of right heart failure (RHF) are diverse and include acute myocardial infarction (AMI), post-surgery or heart transplant, left ventricular assist device (LVAD) implantation and pulmonary embolism.

How is right heart failure diagnosed?

Given that right ventricular failure (RVF) is a hemodynamic problem, assessment of hemodynamic parameters including central venous pressure (CVP) and cardiac output or index, using the pulmonary artery (PA) catheter in combination with cardiac echocardiography, represents the gold standard for evaluation of RV function. Kapur et al. suggest the following hemodynamic variables to assess RV function and the cut-off values depending on the etiology of RVF.⁶

Hemodynamic Formulas to Assess RV Function

Table 1. Hemodynamic Formulas to Assess Right Ventricular Function

CO indicates cardiac output; LVAD, left ventricular assist device; MI, myocardial infarction; mPAP, mean pulmonary artery pressure; PA, pulmonary artery; PADP, pulmonary artery diastolic pressure; PASP, pulmonary artery systolic pressure; PCWP, pulmonary capillary wedge pressure; RAP, right atrial pressure; RV, right ventricular; RVF, right ventricular failure; and SV, stroke volume.

Three-dimensional echocardiography represents an accurate method to assess RV size, contractility and ejection fraction.¹ The American Society of Echocardiography (ASE) suggests quantitative assessment of RV function by at least one of the following parameters:^1,7

• Tricuspid annular plane systolic excursion (TAPSE, normal reference limit ≥ 18 mm)
• RV fractional area change (RVFAC, normal value > 35%)
• RV tissue Doppler S velocity (normal value > 10 cm/s) of the tricuspid annulus

Which Impella® heart pump is FDA-approved for right heart failure?

The Impella RP with SmartAssist and Impella RP Flex™ with SmartAssist are the only devices designated by the FDA as a safe and effective therapy for right heart failure. The Impella RP received FDA pre-market approval (PMA) for use in acute heart failure on September 20, 2017 (P170011).⁸

The Impella RP is a 22Fr 3-D catheter-based microaxial pump approved by the U.S Food and Drug Administration (FDA) for use in acute RHF for up to 14 days.⁹ The catheter pump is advanced antegrade under fluoroscopic guidance over a 0.027-inch platinum super-stiff wire and positioned across the tricuspid and pulmonary valves through a 23Fr peel-away sheath inserted in the femoral vein. The pump inflow is positioned in the inferior vena cava (IVC) and the outflow in the pulmonary artery (PA); thus, the pump aspirates blood from the IVC and expels it into the PA at a rate of up to >4 L/min, thereby directly bypassing the RV.

What clinical evidence was used for FDA approval of Impella RP for acute right heart failure?

Impella RP is the most studied right-sided device and the only percutaneous technology with FDA approval designating it as safe and effective for right heart support. Its exclusive FDA approval is a result of five years of research that included:¹⁰

• RECOVER RIGHT, an FDA-approved, prospective, multicenter, single-arm study, which commenced after Abiomed received FDA investigational device exemption (IDE) approval in November 2012 and concluded in 2014
• HDE approval study, which was completed in January 2015
• A Continuous Access Protocol (CAP)

What are the results of the post-approval study of Impella RP?

The 18-month post-approval study (PAS) submitted to the FDA for Impella RP included 42 patients.¹¹ Of the 42 patients, the FDA determined that only 14 patients met the inclusion criteria for the RECOVER RIGHT pre-market trial and 28 patients received Impella RP as a salvage therapy. Salvage patients were those who received Impella RP > 48 hours after cardiogenic shock and those who sustained out-of-hospital cardiac arrest.

Based on the survival rate of 64% in non-salvage patients, the FDA validated that the post-approval study demonstrates Impella RP is safe and effective for treatment of right heart failure.¹⁰

What are the best practices for use of Impella RP for right-sided support?

Abiomed encourages clinicians to select patients and time Impella RP implantation appropriately. Clinicians should review the inclusion and exclusion criteria for Impella RP and follow guidelines, which recommend implantation of Impella RP within 48 hours of cardiogenic shock onset caused by right side failure.