Address for correspondence:
Shuvodra Routh, MD
200 Lothrop Street, N-715
Pittsburgh, PA 15213
E-mail: rouths@upmc.edu, Fax:
412-692-4944
Abstract:
We report a case of acute right ventricular failure in a patient with
cardiogenic shock on left-sided mechanical circulatory support with
Impella 5.0. The patient was successfully bridged to heart
transplantation using additional right-sided support with ProtekDuo. Key
learning points of the case include prompt recognition of right
ventricular failure in patients on left-sided support, early
consideration of right-ventricular mechanical support platforms, and
timely deployment of right-sided mechanical support.
Case:
A 61-year-old man with non-ischemic cardiomyopathy and inotrope
dependence was admitted for acute cardiogenic shock. Admission vitals
and physical exam on his home dose of milrinone (0.375mcg/kg/min) showed
the following: blood pressure (BP) 99/63mmHg, regular heart rate of 115
beats/min, normal oxygen saturation on room air, jugular venous
distention to 14cm, and cool extremities with significant bilateral
lower extremity edema. Notable laboratory findings on initial
presentation were creatinine 1.5mg/dL (baseline 1.1mg/dL), lactate
0.7mmol/L, LDH 274IU/L, normal transaminases and bilirubin.
Echocardiogram showed globally reduced systolic function with left
ventricular ejection fraction (LVEF) 10-15%, dilated left ventricle
with end-diastolic diameter 7.4cm, mildly reduced global systolic
function of right ventricle (RV) with mild dilation, and RV wall
thickness with no thrombus. Given poor response to diuresis and
worsening renal function refractory to escalating doses of milrinone, a
right heart catheterization (RHC) was performed while the patient was on
milrinone 0.50mcg/kg/min. RHC was consistent with elevated biventricular
filling pressures and low cardiac output (Table 1). An Impella 5.0 was
placed for mechanical left-ventricular (LV) support, which resulted in
clinical and symptomatic improvement. The patient remained on stable
inotropic and mechanical circulatory support over the next several days.
Continued hemodynamic monitoring with a pulmonary artery catheter (PAC)
showed stable central venous pressures (CVP) of 6-8mmHg and PA
saturations of 55-60%. About a week after Impella placement, he was
noted to have an acute increase in his CVP to 30mmHg, a decrease in PA
saturation to 36%, cardiac index 1.8L/m2, worsening
hypoxia, and hypotension (BP 88/59). These hemodynamic changes were
preceded by a 37-beat run of ventricular tachycardia followed by
spontaneous return to sinus rhythm. Bedside cardiac ultrasound revealed
severely reduced RV function. Figure 1 shows the CVP trend leading up to
this event.
Additional Medical/Surgical History:
Implantable cardioverter-defibrillator (ICD) placement, Chronic kidney
disease (stage II)
Differential Diagnosis:
The differential for this patient’s acute RV failure includes:
- RV infarction
- RV failure precipitated by ventricular arrhythmia
- Acute-on-chronic RV failure precipitated by left-ventricular assist
device
- Pulmonary embolism
Investigations:
Laboratory markers of end-organ dysfunction showed an uptrend in serum
creatinine and total bilirubin. Chest radiograph revealed worsening
bilateral pulmonary edema. From PAC monitoring, the patient’s pulmonary
artery pulsatility index (PAPI) was determined to be 1.1 (systolic PA
pressure 50mmHg, diastolic PA pressure 22mmgHg, CVP 30mmHg as a
surrogate of right atrial pressure).
Management:
Due to acute RV shock, the patient urgently underwent placement of a
right-ventricular assist device (RVAD). A Protek Duo extracorporeal pump
was placed for RV support. Flow rates of the right- and left-sided
devices were adjusted to prevent LV overload. The patient’s hemodynamics
improved following RVAD placement. The oxygenator was able to be spliced
out from the Protek Duo circuit within 2 days of placement of the
device, but the patient remained dependent on mechanical circulatory
support (MCS) with the Impella and Protek Duo for biventricular failure.
The patient was designated Status 1 on the heart transplant listing.
Learning Objectives:
To recognize the importance of early detection of RV failure through
close monitoring of RV hemodynamics in a patient with a
left-ventricular assist device.
To consider the options available for percutaneous RV support, and
understand the applications and limitations of RV support platforms.
Discussion:
Up to 20% of patients have RV failure following placement of a LV
assist device (LVAD) (1). The mechanisms for this are varied. With left
ventricular mechanical support, as cardiac output normalizes, RV preload
increases, which can unmask chronic RV dysfunction and manifest as RV
shock. Bowing of the interventricular septum towards the LV due to
mechanical unloading of the LV can also precipitate RV dysfunction (2).
Additionally, ventricular arrhythmias or defibrillator shocks could
compromise RV function. In rare cases, embolic phenomena to the coronary
or pulmonary vasculature can also result in RV failure, even with
therapeutic anticoagulation. In the case presented, the etiology of the
patient’s acute RV failure was hypothesized to be a result of
ventricular arrhythmias or chronic RV failure unmasked by Impella
placement. The patient underwent heart transplantation within 5 days of
the onset of RV shock, and pathology of the native heart unexpectedly
revealed an acute RV infarct from a suspected right coronary artery
embolus (Figure 2).
The incidence of biventricular MCS necessitated by RV failure after LVAD
placement is reported to be between 9-37% (3). Early detection of RV
failure can be implemented by close hemodynamic monitoring with a PAC
and using echocardiographic data. In patients with RV shock refractory
to initial medical management, early mechanical support with a right
ventricular assist device (RVAD) should be considered. The PAPI index
has been shown to be an independent predictor of RV failure and need for
RVAD implantation in patients on LVADs. A prior study identified a PAPI
of <1.85 to be a sensitive predictor of RV failure following
continuous-flow LVAD placement (4).
Percutaneous RVAD options include venoarterial extracorporeal membrane
oxygenation (VA-ECMO), Impella RP, TandemHeart RVAD and Protek Duo.
VA-ECMO is an indirect method of bypassing the RV, whereas the other
devices directly bypass the RV by providing a RA to PA conduit. VA-ECMO
and Protek Duo have the additional benefit of oxygenating capabilities
(5) (6). Table 2 summarizes the hemodynamic effects and several of the
advantages and limitations of these devices. All these devices come with
the risk of bleeding and thromboembolic complications. A distinct
advantage of Protek Duo is the ability of this dual-lumen device to be
percutaneously introduced through the right internal jugular vein,
allowing the patient to remain ambulatory (6). Of note, these devices
are for temporary RV support; new technologies for durable RV support
remain under investigation.
Follow-Up:
The patient was discharged home after undergoing a heart transplant, and
is doing well post-transplantation.
Conclusions:
In this patient, acute RV shock was precipitated by an embolic RV
myocardial infarction, leading to biventricular failure requiring dual
support with Impella 5.0 and Protek Duo, allowing successful bridging to
transplant. This case exemplifies the importance of prompt recognition
of RV failure, and selection of appropriate MCS devices for RV support.
References:
- Ravichandran, A., Baran, D. et al.(2018). Outcomes with the Tandem
Protek Duo Dual-Lumen Percutaneous Right Ventricular Assist Device.
ASAIO Journal, 64(4), 570-572.
- Toennes, B., Garan, A.(2016). Percutaneous Right Ventricular Support
Devices for Right Ventricular Failure. JACC.
- Fida N., Loebe M., et al.(2015). Predictors and management of right
heart failure after left ventricular assist device implantation.
Methodist Debakey Cardiovasc J., 11(1):18-23.
- Morine K., Kiernan M., et al.( 2016). Pulmonary artery pulsatility
index is associated with right ventricular failure after left
ventricular assist device surgery. J Card Fail., 22:110–116.
- Kapur, N., Esposito, M., et al.(2017). Mechanical Circulatory Support
Devices for Acute Right Ventricular Failure. Circulation, 136(3),
314-326.
- Nicolais, C., Suryapalam, M., et al.(2018). Use Of Protek Duo Tandem
Heart For Percutaneous Right Ventricular Support In Various Clinical
Settings: A Case Series. JACC, 71(11).