Percutaneous devices have been developed to provide hemodynamic support during complex coronary interventions. However, the presence of a mechanical aortic valve excludes the use of the Impella left ventricular assist device. We describe the use of the alternative TandemHeart left ventricular assist device (CardiacAssist) for a complex coronary intervention involving an unprotected left main coronary lesion in a patient with decompensated heart failure and a mechanical aortic valve.
A 79 year-old female was transferred to our facility with non-ST elevation myocardial infarction (NSTEMI) with a peak troponin of 49.3. Her past medical history was significant for aortic valve replacement with a mechanical Top Hat valve (Carbomedics) and 2-vessel coronary artery bypass graft surgery (CABG) with saphenous vein graft (SVG) to left anterior descending artery (LAD) and SVG to diagonal branch 9 years prior. In addition, she was known to have had a previous cerebrovascular accident and ischemic cardiomyopathy with a left ventricular (LV) ejection fraction of 35%.
Coronary angiogram revealed severe ostial left main coronary artery (LMCA) 95% stenosis, with a distal LAD 100% occlusion, left circumflex artery (LCX) proximal 100% occlusion, and right coronary artery (RCA) ostial 80% stenosis. Furthermore, the SVG to LAD and SVG to diagonal arteries were both occluded at the ostium. She was also noted to have significant peripheral arterial disease with 90% right external iliac artery stenosis, 95% right common femoral artery (CFA) stenosis in the proximal portion and 100% right superficial femoral artery (SFA) occlusion at its origin.
Due to the complexity and extensive nature of disease, the cardiothoracic surgery team was consulted for surgical revascularization. However, in the setting of re-do open heart surgery with mechanical aortic valve, severe LV dysfunction, and NSTEMI, the patient was deemed to carry a high surgical risk. Therefore, a percutaneous revascularization approach with hemodynamic support using an LV assist device was pursued.
Access was obtained in bilateral femoral arteries and bilateral femoral veins.
Femoral angiograms confirmed severe iliac disease bilaterally and initial intervention was focused on the left iliac arteries in order to support the placement of the TandemHeart arterial cannula. After balloon angioplasty of the left external iliac artery using a Mustang 6 x 40 mm balloon (Boston Scientific) at 12 atm, a Complete SE 6 x 60 mm self-expanding stent (Medtronic) was deployed in the left external iliac artery and post-dilated using the same balloon at 12 atm. An Express 7 x 27 mm stent (Boston Scientific) was then deployed at the lesion in the left common iliac artery at 14 atm, with good expansion and no residual gradient across both lesions. The left femoral artery sheath was then up-sized to a 10 Fr sheath.
An intracardiac echocardiography (ICE) catheter (Biosense Webster) was then advanced from the left femoral vein into the right atrium to image the interatrial septum. A Brockenbrough needle was advanced through an SR1 transseptal sheath from the right femoral vein access and positioned against the fossa ovalis. Needle entry into the left atrium (LA) was confirmed with LA pressure tracing and aterial oxygen saturations. The TandemHeart 21 Fr transseptal cannula was then advanced over an Amplatz stiff wire (Cook) after serial dilations of the right femoral vein and interatrial septum into the left atrium, visualized using ICE imaging. A 10 Fr arterial cannula was then inserted into the left femoral artery and hemodynamic support initiated using the TandemHeart LV assist device, with systemic output of up to 2.5 L/min.
A 6 Fr JL 4 guide was used to engage the LMCA and a Kinetix wire (Boston Scientific) advanced across the lesion into the distal LAD. An NC Quantum Apex 4 x 12 mm balloon (Boston Scientific) was used to pre-dilate the LMCA lesion at 12 atm with good expansion. An Integrity 4 x 12 mm stent (Medtronic) was deployed, extending into the LAD at 10 atm. The Integrity stent was post-dilated using the same balloon at 12 atm with good angiographic result and TIMI-3 flow into the LMCA and LAD segments.
Next, a JR 4 guide was used to engage the RCA and a PT Graphix wire (Boston Scientific) advanced across the lesion into the distal RCA. An NC Sprinter 2.5 x 12 mm balloon (Medtronic) was used to pre-dilate the ostial lesion at 18 atm, an Integrity 3 x 12 mm stent (Medtronic) deployed at 18 atm, and the stent balloon used to post-dilate the ostium at 18 atm, with good angiographic result and TIMI-3 flow.
At this point, the TandemHeart LV assist device was discontinued and the cannulas clamped. The femoral arterial and venous sheaths were sequentially withdrawn and hemostasis achieved using manual compression. The patient was transferred to medical intensive care unit for post percutaneous coronary intervention care without complications. She was eventually discharged to a rehabilitation center in stable condition after therapeutic anticoagulation on warfarin for her mechanical aortic valve.
Significant hemodynamic compromise leading to cardiogenic shock, in the setting of acute myocardial infarction, decompensated chronic heart failure, acute mitral valve regurgitation, or ventricular septal defect, clearly increases the risk of any interventional procedure. Pharmacologic therapy, including vasoconstrictors and positive inotropes, may be helpful, but is often not sufficiently potent to sustain hemodynamics or inhibit undesirable side effects such as increased arrhythmias or worsened tissue perfusion.
Percutaneous LV assist devices have been proven to reduce cardiac workload and provide circulatory assistance and myocardial protection during complex coronary revascularization. The use of the Impella 2.5 LV assist device (Abiomed) has been shown to reduce the incidence of major adverse events during high-risk coronary interventions1, allowing even complex unprotected LMCA revascularization as previously reported.2 However, the presence of a mechanical aortic valve excludes the use of this device.
TandemHeart is an alternative percutaneous LV assist device currently approved for short-term hemodynamic support, up to 6 hours. The device consists of an extracorporeal centrifugal pump that withdraws blood from the left atrium through a 21 Fr transseptal cannula introduced via the femoral vein. Blood is then pumped by the device and delivered into one or both femoral arteries through 15 or 18 Fr cannulae. The pump thus functions in parallel with the left ventricle in moving blood from the left atrium to the aorta.
Preliminary results showed that this device can improve hemodynamics in patients with cardiogenic shock caused by myocardial infarction and other causes. Studies also showed a reduction in serum lactate levels, an indication that there is improved tissue perfusion and oxygenation, and thus reversal of cardiogenic shock state. In a more recent study, 41 patients with cardiogenic shock owing to acute myocardial infarction failing medical treatment were randomized to treatment with either an intra-aortic balloon counterpulsation pump (IABP) or the TandemHeart assist device.3 The IABP had almost no effect on the hemodynamics of the heart, but the TandemHeart device significantly increased cardiac output and blood pressure while significantly decreasing pulmonary capillary wedge pressure and serum lactate. In a trial by Burkhoff et al, TandemHeart was evaluated for safety in a feasibility study consisting of 13 patients with cardiogenic shock from 5 centers.4 Hemodynamic variables, including cardiac index, mean arterial pressure and pumonary capillary wedge pressure, were improved following initiation of TandemHeart support. Survival rate was 54% in this high-risk group of patients.4
In a summary of several technologies for treatment of acute myocardial infarction complicated by cardiogenic shock, Garatti et al cited TandemHeart as having the highest wean and highest survival rate of 75% and 58%, respectively.5 Bleeding remained the leading complication of TandemHeart, and no significant left-to-right shunt has been observed following removal of the trans-septal cannula.6
In the case herein, the unprotected LMCA lesion in the setting of NSTEMI and ischemic cardiomyopathy was complicated by the presence of a mechanical aortic valve. We report the successful use of TandemHeart as an alternative percutaneous LV assist device in order to perform such complex coronary interventions.
The authors may be contacted via Dr. Jon George at: firstname.lastname@example.org
- Dixon SR, Henriques JP, Mauri L, et al. A prospective feasibility trial investigating the use of the Impella 2.5 system in patients undergoing high-risk percutaneous coronary intervention (The PROTECT I Trial): initial US experience. JACC Cardiovasc Interv 2009; 2: 91-96.
- Desai H, George JC. Complex left main coronary intervention for in-stent restenosis facilitated by use of percutaneous left ventricular assist device. Cath Lab Digest 2011 November; 19(11): 26-30.
- Thiele H, Sick P, Boudriot E, et al. Randomized comparison of intra-aortic balloon support versus a percutaneous left ventricular assist device in patients with revascularized acute myocardial infarction complicated by cardiogenic shock. Eur Heart J 2005; 26(13): 1276-1283.
- Burkhoff D, O’Neill W, Brunckhorst C, Letts D, Lasorda D, Cohen HA. Feasibility study of the use of the Tandem Heart percutaneous ventricular assist device for treatment of cardiogenic shock. Catheter Cardiovasc Interv 2006; 68 (2): 211-217.
- Garatti A, Russo c, Lanfranconi M, et al. Mechanical circulatory support for cardiogenic shock complicating acute myocardial infarction: an experimental and clinical review. ASAIO J 2007; 53 (3):278-287.
- Thiele H, smalling RW, Schuler GC. Percutaneous left ventricular assist devices in acute myocardial infarction complicated by cardiogenic shock. Eur Heart J 2007;28(17):2057-2063.
Disclosure: Dr. Desai and Dr. Kovach report no conflicts of interest regarding the content herein. Dr. George reports he is a consultant for Boston Scientific and Abiomed.