Efficacy and Safety of Percutaneous Life Support During High-Risk Percutaneous Coronary Intervention, Refractory Cardiogenic Shock and In-Laboratory Cardiopulmonary Arrest

ABSTRACT: Background. High-risk percutaneous coronary interventions (PCI), refractory cardiogenic shock and in-lab cardiac arrest are all associated with significant mortality. Percutaneous left ventricular assist devices (pLVAD) and CPS (cardiopulmonary support) have been used to support such patients. However, the extent to which the use of these devices can improve outcomes in this patient subset is not known. Methods. We evaluated clinical features, efficacy and safety outcomes in a retrospective cohort of 39 patients, treated either with pLVAD or CPS for support of high-risk PCI, cardiogenic shock or in-lab cardiac arrest. The TandemHeart and a new versatile Multifunctional Percutaneous Heart (MPH) system, with both CPS and LVAD capability, were used and assessed. Results. 19 patients received the TandemHeart and 20 received the MPH system. The MPH system was used as a pLVAD in 12 and to provide CPS in 8 patients. Procedural efficacy was 100%. Emergent institution of CPS, in the setting of cardiac arrest, was able to support 7 out of 8 patients and resulted in a 50% survival to hospital discharge rate. Overall, in-hospital death and 30-day major adverse cardiac event rates were 28.2% and 35.9%, respectively. The risk of vascular complications and bleeding was relatively small. Conclusions. pLVADs are effective in supporting patients during high-risk cardiac (coronary and structural heart) interventions, with a low risk of device-related complications. Further, the expeditious use of CPS in the catheterization laboratory can improve survival in a selected subset of patients with refractory cardiogenic shock and cardiac arrest. J INVASIVE CARDIOL 2011;23:141–147 ———————————————————— Percutaneous coronary intervention (PCI) in the setting of left ventricular (LV) dysfunction [left ventricular ejection fraction (LVEF) 1 In current interventional practice, PCI and procedures like aortic valvuloplasty often need to be performed in patients with the above-mentioned as well as other high-risk angiographic and clinical features. These include unprotected left main or left main equivalent stenosis, last remaining vessel/conduit, rotatational atherectomy with severely depressed LV function, refractory cardiogenic shock and resuscitation from cardiac arrest.^2,3 Many of these patients are not considered to be surgical candidates and are at high risk of death due to ischemia and pump failure. Currently employed support devices include the intra-aortic balloon pump (IABP) cardiopulmonary support (CPS) system (C.R. Bard Inc., Murray Hill, New Jersey), TandemHeart (Cardiac Assist Inc., Pittsburgh, Pennsylvania) and Impella (Abiomed, Danvers, Massachusetts). The TandemHeart percutaneous left ventricular assist device (pLVAD) was first used clinically in May 2003 to support high-risk PCI.⁴ Since then, it has been successfully used to support high-risk intervention, such as unprotected left main PCI,^5–9 management of refractory cardiogenic shock,¹⁰ as a bridge to heart transplant or long-term assist device,^11,12 support of the right ventricle,¹³ support of the ventricle during aortic valvuloplasty,¹⁴ and after myocarditis or post-myocardial infarction ventricular septal defect (VSD).^15,16 In studies comparing the TandemHeart system to the IABP, the former has provided better hemodynamic support, but without a survival advantage in the setting of refractory cardiogenic shock.^17,18 A pLVAD is able to maintain an adequate cardiac output and support vital organ perfusion, despite severely compromised LV systolic function. However, in the setting of cardiopulmonary arrest, both the heart and lungs have to be bypassed with institution of an extracorporeal circuit capable of oxygenating venous blood and returning it to the arterial system to preserve life. This has been done in the cardiac catheterization laboratory with institution of percutaneous extracorporeal cardiopulmonary bypass or support. Due to some limitations in using the TandemHeart device for CPS, we have assembled an alternate and novel percutaneous life-support system at our institution: the so-called Multifunctional Percutaneous Heart (MPH). This is a versatile system that can be used either as an LV assist device or for CPS. It can be easily transitioned from a pLVAD application to provide CPS by opening connections to an oxygenator which is incorporated in the circuit. It can also be used to provide emergency CPS in patients with cardiac arrest, in whom there is no time for transseptal placement of the venous cannula.

Methods

Study population. Nineteen patients underwent placement of the TandemHeart system between April 2006 and October 2008. This cohort consisted of 2 subsets of patients. The first was an elective group, in which support was initiated electively for high-risk coronary or structural heart intervention. The second was the emergent group, which consisted of patients who were either unstable prior to intervention or who became hemodynamically unstable following periprocedural events. Elective high-risk patients consisted of those requiring PCI of an unprotected left main/left main equivalent anatomy, PCI on the last remaining vessel, multivessel PCI with rotational atherectomy or aortic valvuloplasty, almost always in the setting of a depressed LVEF. The emergent group consisted of patients with refractory cardiogenic shock or in-lab cardiac arrest as a bridge to LVAD/transplant. The TandemHeart device was used exclusively as a pLVAD. Twenty patients underwent placement of the Multifunctional Percutaneous Heart (MPH) system between February 2008 and March 2009. This cohort was also comprised of an elective group of patients in whom the device was used to support high-risk PCI and an emergent group of patients with cardiogenic shock or cardiopulmonary arrest. Among 20 patients, the MPH device was used as a pLVAD (MPH-L) in 12 patients and for CPS in 8 patients (MPH-CPS), mainly for the management of in-lab cardiopulmonary arrest. Given the combination of high-risk PCI and poor hemodynamics in most patients in both cohorts, we elected to use a percutaneous LV assist device versus an IABP. MPH device. The MPH disposable circuit incorporates a rotary pump, oxygenator, tubing, high-flow stopcocks and a pressure display set. The efficient and durable centrifugal pump has a low priming volume and carries a low risk of hemolysis. A Quadrox D oxygenator (Maquet, Cardiopulmonary, Hirrlingen, Germany) is used with polymethylpentene diffusion fibers that are resistant to plasma leakage during long-term support. It contains a hydrophobic filter at its apex which facilitates priming and removal of air that may be inadvertently entrained during use. The circuit tubing is comprised of 3/8th inch venous and arterial lines with Trillium coating (Medtronic Cardiopulmonary, Minneapolis, Minnesota) for improved biocompatibility. A DLP pressure display set (Medtronic Cardiopulmonary, Minneapolis, Minnesota) is used to assist with monitoring oxygenator efficiency. High-flow stopcocks can be used to implement continuous veno-venous hemofiltration (CVVH) or hemodialysis (CVVH-D). When MPH is used for right or left heart support, we bypass the oxygenator, while maintaining its integrity, in the event pulmonary support is required. Pulmonary support is easily administered by transitioning a few tubing clamps. The MPH system was designed for flows up to 7 L/min and has a dynamic priming volume of approximately 200 ml, when used as a pLVAD, to approximately 450 ml when the oxygenator is deployed. The MPH is pre-assembled and filled with normal saline. Therefore, the device is ready for emergent application immediately and allows rapid activation of circulatory support in the cardiac catheterization laboratories or cardiac intensive care unit. The pre-assembled and filled device needs to be replaced only once a month, if not used. A pictorial representation of the device is shown in Figure 1. Implantation technique. The implantation technique of both the TandemHeart and the MPH system were identical when used as a pLVAD. Using intracardiac echo (ICE) guidance, a trans-septal puncture was performed. A 21 French (Fr) venous cannula was advanced over a stiff guidewire from the femoral vein into the left atrium. The common femoral artery was accessed and ‘preclosed’ with two Perclose Proglide (Abbott Laboratories, Abbott Park, Illinois) devices. A 15–18 Fr arterial cannula was then inserted. After connecting the tubing to the pump, circulatory support was initiated with left atrial to femoral bypass. When the MPH was used for CPS, the venous cannula was positioned in the right atrium, and the oxygenator added to the circuit. Conversion from pLVAD to CPS could easily be performed by pulling the venous cannula back from the left to the right atrium, and transitioning tubing clamps to route blood through the oxygenator. In 1 case of TandemHeart and 2 cases of MPH, the arterial cannula was inserted after axillary cut down. Heparin was used in most cases, while bivalirudin was used in confirmed or suspected HIT cases. Arterial closure was performed using Perclose, while a subcutaneous “figure of 8” stitch was used to remove the venous cannula in most cases. In some cases, elective surgical closure of the arteriotomy was performed. Study endpoints. The efficacy endpoint in TandemHeart and MPH-L cases was procedural efficacy, defined as the successful completion of the procedure (coronary, valvular or structural heart intervention) without development of refractory hypotension, cardiac arrest or sustained ventricular arrhythmias. For the MPH-CPS, the primary efficacy endpoint was successful support of cardiopulmonary function until a cardiac rhythm associated with a mean arterial pressure of ≥ 50 mmHg (with or without vasopressors) could be obtained. The secondary efficacy endpoint was survival to hospital discharge. The primary safety endpoint in all cases was the incidence of in-hospital death and 30-day major adverse cardiovascular events (MACE), defined as a composite of death, recurrent MI, stroke and urgent target vessel revascularization (TVR). Recurrent MI was defined as elevation of CK-MB > 3 times the upper limit of normal. Secondary safety endpoints included vascular complications, renal failure and bleeding defined by number of packed red blood cell units transfused within 48 hours of device insertion. We also calculated an additive and logistic EuroSCORE (European System for Cardiac Operative Risk Evaluation)²⁰ on each patient and SYNTAX²¹ scores in patients undergoing PCI of native coronary arteries. Data analysis. Means and standard deviatiosn (SD) are used to summarize continuous variables. Categorical variables are presented as frequencies and percentages. SYNTAX scores were calculated in those patients undergoing PCI of native coronary vessels, and summarized using means ± SD. Additive and logistic EuroSCOREs were also calculated in patients undergoing PCI and presented as medians. Due to a limited sample size with a small number of endpoints (such as death), we were unable to perform a multivariate analysis of predictors of death or 30-day MACE.

Results

Clinical data. Nineteen patients underwent placement of the TandemHeart device for the following indications: unprotected left main/left main equivalent PCI (n = 7); last remaining vessel (n = 2); multivessel PCI with rotational atherectomy in setting of severe LV dysfunction (n = 1); aortic valvuloplasty with depressed LVEF of 15–35% (n = 4); refractory cardiogenic shock as bridge to LVAD/transplant (n = 2); in-lab cardiac arrest as bridge to LVAD/transplant (n = 1); and high-risk PCI with high jeopardy score or severe LV dysfunction and cardiogenic shock (n = 2). The device was placed electively in 16 patients and emergently in 3 patients. Twenty patients underwent placement of the MPH device. Support was placed for unprotected LM PCI with cardiogenic shock (n = 1); PCI on the last remaining vessel (n = 4); high-risk PCI in setting of cardiogenic shock (n = 1); combined PCI and aortic valvuloplasty with depressed LVEF (n = 1); VSD repair with cardiogenic shock (n = 1); in-lab or pre-lab cardiac arrest (n = 7), with 1 case in the setting of ST-segment elevation myocardial infarction (STEMI); rotational atherectomy with depressed LVEF (n = 1); refractory post-STEMI cardiogenic shock (n = 2); cardiogenic shock before primary PCI (n = 1); and high-risk PCI with high jeopardy score and depressed LV function (n = 1). The device was placed electively in 7 patients and emergently in 13 patients. The mean patient age was 63 ± 14 years (range, 33–87 years), with 23% females. Diabetes was present in 20.5%, and 33.3% had undergone prior coronary artery bypass graft (CABG) surgery. Mean LVEF was 27.9 ± 15.3%, with an LVEF 20 as ventricular tachycardia/ventricular fibrillation, aborted sudden death, pre-operative cardiac massage, pre-operative ventilation before anesthetic room, pre-operative inotropes or IABP, preoperative acute renal failure (anuria or oliguria Procedural data. The mean time from the point when the decision to institute CPS, in the setting of in-lab arrest, was made, to the time the pump was started was 26 ± 10.6 minutes (although this is based on analysis of only 5 cases in which it was possible to obtain accurate times from the procedure log). Average flow rate delivered by the TandemHeart was 3.45 ± 0.83 L/min versus 3.38 ± 0.8 L/min for the MPH device, with no significant difference between the flows achieved (p = 0.717). Average flow rate delivered by the 2 devices, when analyzed together, was 3.3 ± 0.8 L/min. Average duration of flow was 376.5 ± 677.5 minutes (range, 30–5760 minutes). Nine patients required support for > 6 hours. The longest duration of pLVAD support was 96 hours in 2 patients using the TandemHeart device and 24 hours for CPS using the MPH device. In 1 patient, after initial stabilization with CPS, the MPH device was reconfigured to function as a pLVAD by performing a trans-septal puncture Efficacy endpoint. Device implantation was successful in all cases. Procedural efficacy, in the TandemHeart and MPH-L cases, as previously defined, was 100%. In 7 out of 8 MPH-CPS cases, institution of CPS allowed support of cardiopulmonary function until a cardiac rhythm associated with a mean arterial pressure of ≥ 50 mmHg could be restored, and definitive treatment, with PCI or emergency CABG, could be instituted. The primary efficacy endpoint was therefore achieved in 87.5% of patients. In 1 patient with suspected free wall rupture, there was insufficient inflow due to exsanguination and the patient expired, despite pericardiocentesis and volume expansion. The secondary efficacy endpoint in this group (survival to hospital discharge) of 8 patients was 50%. Safety endpoints. Overall in-hospital death rate was 28.2% with 11 deaths. 30-day MACE rate was 35.9%, with a total of 11 deaths; 2 recurrent MIs, 1 of which required TVR, and 1 stroke. All but 2 deaths were due to refractory pump failure. In the remaining 2, the TandemHeart device served successfully as a bridge to transplant in 1 case and a surgically implanted biventricular assist device in another; nonetheless, both died from multi-organ failure while in the hospital. Univariate predictors of death were arterial cannula size, cardiac arrest, prior MI, STEMI and pump time. Due to small sample size, a multivariate analysis could not be performed. Vascular complications were noted in 2 patients in the TandemHeart group — 1 due to a failed Perclose requiring surgical repair and 1 small arteriovenous fistula managed conservatively. One patient in the MPH-L group developed critical limb ischemia and rhabdomyolysis, requiring a femoral graft and fasciotomy. The average number of packed red blood cell units transfused within 48 hours of the initiation of the procedure was 1.74 ± 2.4. The MPH devices used in this study were preassembled and filled. Average time between preparation and usage was 14.5 days. There was no documented infection. We utilized a “figure 8” stitch technique19 to close the venous access immediately after removal of venous cannula (20–21 Fr) while still fully anticoagulated. This technique was initially developed by the authors. Complete hemostasis was achieved in all patients. Table 2 outlines procedural, efficacy and safety data.

Discussion

This study demonstrates that institution of percutaneous life support for high-risk intervention is clinically efficacious in maintaining an adequate systemic blood pressure to allow for successful completion of the procedure. In the setting of refractory cardiogenic shock and cardiac arrest, rapid institution of LV unloading and cardiopulmonary support acts as a temporizing measure while definitive treatment is undertaken. Both the TandemHeart and the MPH device were effective in this regard, with a clinically acceptable rate of complications. In the absence of a true control group, we can comment on the safety and efficacy of this technology based on safety and efficacy outcomes reported with percutaneous life support in the literature. The TandemHeart device was used for diverse indications in our study. Consequently, assessment of its performance should be made in context of the specific patient subgroup and indication for support, since published data are also based on results in specific populations and indications. The following patient populations and indications were studied. PCI on the unprotected left main (ULM) coronary artery. PCI of the ULM coronary artery, by experienced operators in high-volume centers using contemporary techniques, can be accomplished with low procedural morbidity and mortality.²² However, the risk of ULM PCI increases significantly in the setting of severe LV dysfunction, additional multivessel/complex coronary artery disease (elevated SYNTAX score), poor hemodynamics, high euroSCORE and in those cases where abrupt closure would be catastrophic, as in the case of an occluded or diseased right coronary artery (RCA).^23–25 The LVEF in the 8 cases of ULM PCI in our series was 36.2 ± 6.9%. In a study of ULM PCI in the setting of LVEF 24 In addition, 4 out of the 8 cases of ULM PCI in our series were associated with either an occluded (n = 3) or severely diseased RCA (n = 1). In a study evaluating the impact of RCA disease on outcomes of ULM PCI, patients with RCA disease were noted to have a significantly higher rate of cardiac death (17.7%) compared with those without RCA disease (6.7%; p = 0.056). Notably, patients with a CTO in the RCA had a significantly higher cardiac mortality (30.0%) compared with patients without RCA disease (6.7%; p = 0.015).²⁵ Two patients requiring ULM PCI in our series required either adjunctive rotational atherectomy or rheolytic thrombectomy of the LM, both of which are associated with higher risk than stand-alone stenting. Finally, all cases involved stenting of the distal LM, which is associated with a higher rate of adverse events than stenting the ostium or shaft of the vessel. There are limited data with use of TandemHeart for ULM PCI. In a case series of 5 patients undergoing ULM or last remaining conduit PCI with TandemHeart support, mortality was 20%. LVEF was not stated for all cases in that series.⁴ In another series of 6 patients, with a mean LVEF of 33% and the majority undergoing ULM PCI, 30-day survival was 83%.⁵ In our study, 30-day survival after 8 cases of ULM/LM equivalent PCI, with a mean SYNTAX score of 28.9 ± 8.2 and LVEF of 32 ± 10.6%, was 100% with TandemHeart. With the MPH, survival was again 100% in 5 cases (LVEF, 24 ± 7.5%). Use in setting of refractory cardiogenic shock associated with STEMI. Theile and colleagues observed a 44% 30-day mortality rate among 18 patients with post-MI cardiogenic shock treated with the TandemHeart device, of which 5 had a post-infarction VSD. Mortality was 31% if the VSD patients were excluded.²⁶ In another study, among 13 patients with pre-procedure cardiogenic shock (despite an IABP in 69%), 7 survived to hospital discharge, with utilization of the TandemHeart device as a bridge to cardiac surgery or PCI.²⁷ In our study, only 1 patient received the TandemHeart for post-STEMI cardiogenic shock and did not survive. This patient had presented with stent thrombosis of an unprotected LM stent and had severe mitral regurgitation (MR) with refractory shock despite IABP and multiple vasopressors. Similarly, none of the 3 patients who received the MPH device for post-STEMI cardiogenic shock survived. One had a VSD (known to be associated with poor survival), and the remaining 2 patients had an LVEF of Use in the setting of cardiogenic shock due to dilated cardiomyopathy. The device has also been used as a bridge to an implantable VAD or heart transplantation. Among 5 patients in whom it was used in the setting of refractory cardiogenic shock or cardiac arrest, there were no deaths at a mean follow-up of 8.4 ± 9.9 months after heart transplantation.²⁸ In our study, the TandemHeart was successfully able to bridge 2 patients with either refractory cardiogenic shock or cardiac arrest due to dilated cardiomyopathy. However, both patients died post-transplant or BiVAD implantation. The MPH was not used for this indication. Use in the setting of PCI with high jeopardy score. Gimelli and associates studied 11 patients with a pre-PCI LVEF of 25 ± 8% and high risk for CABG (mean additive euroSCORE, 12 ± 2; mean logistic euroSCORE, 33 ± 17) who underwent high-risk PCI with TandemHeart support. In-hospital and 30-day mortality was 0%.²⁹ In our study, 2 patients each in the TandemHeart and MPH groups (mean logistic euroSCORE, 44.6 ± 21.6 and 25.6 ± 2.9, respectively) underwent successful high-risk PCI without mortality. Use in the setting of aortic valvuloplasty. One of the first uses of cardiopulmonary support (CPS) described in the United States was for support of aortic valvuloplasty.³⁰ Since then, the use of the TandemHeart device has been described to support 7 patients requiring balloon aortic valvuloplasty (BAV) and their outcomes were compared to 4 patients who had BAV without an LV-assist device.³¹ Of the 7 supported patients, all survived to 1 month, whereas 2 out of 4 unsupported patients died during their hospital stay. The average LVEF was lower in the supported group (24 ± 9% versus 47 ± 10% in the control group). The use of the TandemHeart device allowed a significantly longer balloon inflation time. In our series, LV support was used due to the presence of severe LV systolic dysfunction (average LVEF, 24 ± 7.4%). The presence of LV support allows better tolerance of the rapid right ventricular pacing that is required to prevent balloon displacement during inflation and can allow longer, and thus more precise, inflations. Use in the setting of cardiopulmonary arrest. CPS or bypass instituted by a percutaneous technique to support high-risk coronary angioplasty was first reported in 1988.³⁰ In a study of the emergent institution of percutaneous CPS for the management of 7 patients with cardiac arrest, in the setting of cardiogenic shock or cath lab complications, survival was 57%.³² All survivors received definitive therapy (CABG or repeat percutaneous transluminal coronary intervention), whereas none of the patients who did not receive revascularization survived. In a separate study, survival with CPS was 20% (6 out of 30 patients), with the majority of survivors, again, having undergone revascularization.³³ None of the 7 patients with refractory cardiac arrest survived, despite definitive therapy in 3 patients. A 27% survival to discharge rate was reported with the use of ECMO, during resuscitation of adult cardiac arrest, in which 75% of patients had a primary cardiac diagnosis.³⁴ In our study, 7 out of 8 patients in the MPH group, who needed CPS (MPH-CPS), had pre-lab or in-lab cardiac arrest with ongoing CPR; the remaining patient had pre-procedure cardiogenic shock. MPH-CPS was successful in salvaging 3 out of 7 patients with cardiac arrest and the 1 patient with cardiogenic shock. The 4 patients who survived underwent PCI (n = 3) or CABG (n = 1). Of 4 patients who died, 3 died of complications after successful resuscitation in the catheterization laboratory, whereas 1 died in the laboratory due to free-wall rupture. The overall survival to hospital discharge in the MPH-CPS group was therefore 50% and was 43% for the subgroup with cardiac arrest. Institution of extracorporeal support alone does not effectively treat ischemia in the distribution of an occluded coronary artery. Rapid institution of CPS to maintain vital organ perfusion accompanied by definitive treatment of ischemia with PCI or surgery is therefore of key importance in improving survival to discharge. Of note, mechanical problems and clots in the circuit were noted in 32.2% and 19% of cases in the previously cited study of ECMO in cardiac arrest, respectively.³⁴ In contrast, there were no mechanical problems or clots in the ECMO circuit with the MPH device in our study. The presence of pre-assembled and filled MPH devices in our cath lab allows rapid deployment of the device in the setting of cardiac arrest which, in our estimate, eliminates the 20–30 minute preparation time. This time-saving is critical for patients with cardiopulmonary arrest and may have contributed to the success in our series. Infection is a concern with devices pre-filled with saline; thus, we discard all unused disposable equipment after 1 month. We have not noticed any infectious illness in our series. Of note, this practice is standard of care in pediatric ECMO. The MPH device can be easily assembled with existing products. The cost is approximately 10–15% of other commercially available devices. The easy assembly and low cost provide a new opportunity for hospitals and their patients. Comparison of safety outcomes with previously reported data on peripheral life-support devices. The percentages of bleeding/patients requiring transfusion (TandemHeart 68%, MPH 50%) in our study were higher compared with the 9–31% rates mentioned in 3 previous studies using TandemHeart.^8,27,29 Patients requiring support > 12 hours and those requiring surgical axillary cutdown for arterial cannula placement tended to require more blood products, as expected. It is possible that hemolysis may have contributed to blood loss, although we did not measure indices of hemolysis. Furthermore, we included all transfusions received up to 48 hours after device insertion. The incidence of lower-extremity ischemia was comparable (TandemHeart 0, MPH 5%) with the 4.4–23% rate previously reported with TandemHeart.^8,27Mortality based on SYNTAX and EuroSCORE. We calculated SYNTAX and both additive and logistic EuroSCOREs in the patient population that underwent PCI. Despite a median additive EuroSCORE of 11 and median logistic EuroSCORE of 20.4 in the 27 PCI patients, observed mortality was 14.8%. In a paper by Romagnoli et al, used for validation of the EuroSCORE for prediction of post-PCI in-hospital mortality, a mortality of 5.5% was noted for the median EuroSCORE interquartile range of 9–11 and 28% for the 12–14 range.³⁵ The mean SYNTAX scores and mortality rates among 17 patients who underwent PCI of native coronary vessels were 28.3 ± 14.6 and 17.6%, respectively. Rationale for using percutaneous life support. In contemporary interventional practice, complex PCI is often performed using intra-aortic balloon pump (IABP) or the Impella device.³⁶ The majority of cases in our series consisted of patients requiring complex PCI (unprotected distal left main) with very poor LV function (LVEF for the MPH in our institution is $1,615, compared with $21,000 for TandemHeart and $25,000 for Impella. The cost of the MPH, in fact, is quite comparable to that of an IABP ($800 for disposables). With regard to the regulatory status of the MPH device, all of the components of the MPH are FDA-approved for extracorporeal circulation. We simply built the system to accommodate our needs and identified that it resulted in cost savings. Table 3 provides a summary of the comparison between currently used support devices. Study limitations. We acknowledge that the patient population studied in this study is highly heterogenous and lacks a matched or randomized control population. In the absence of controls, we calculated the additive and logistic EuroScore in the PCI population, which has been validated as an independent predictor of in-hospital mortality in patients undergoing PCI.³⁵ While the EuroSCORE was used to obtain an assessment of high-risk clinical features, we used the SYNTAX score to determine angiographic complexity in patients undergoing PCI of native coronaries. Despite calculating the EuroSCOREs and SYNTAX scores, direct comparisons cannot be made between outcomes in our heterogeneous patient population and the historical control population, which was used to validate the predictive value of these scores. We recognize this as a shortcoming. The current study represents a retrospective cohort study, which is susceptible to bias in assessment of both exposure and outcome. The limited sample size did not allow us to perform multivariate analysis of predictors of death. Nonetheless, as these catastrophic conditions are fortunately infrequent occurrences, our sample size was comparable to, if not more robust than prior series. We were able to quantify angiographic severity of CAD only in patients undergoing PCI of native coronary vessels, since the SYNTAX score applies only to that patient population.

Conclusion

The study is one of the largest single-center experiences with percutaneous life support with a total of 39 patients. Despite a high prevalence of critical pre-procedure state markers (cardiac arrest 20.5%, emergent procedure 28% and cardiogenic shock 20.5%), institution of percutaneous life support in the form of pLVAD or CPS was efficacious and associated with a 100% 30-day survival rate in patients undergoing high-risk PCI and 43% survival to hospital discharge following in-laboratory cardiac arrest. Incidences of death, MACE, bleeding and lower extremity ischemic complications were comparable with previously published data. There were no cases of device malfunction. Further large-scale studies of protocol-based and early use of percutaneous life support for critically ill patients in the cardiac catheterization laboratory are needed to further elucidate the respective potential roles of these devices in this high-risk population.

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———————————————————— From the Division of Cardiovascular Medicine, Vanderbilt University Medical Center and the Vanderbilt Heart and Vascular Institute, Nashville, Tennessee, and ^†Saint Joseph’s Translational Institute and Northside Hospital, Atlanta, Georgia. The authors report no conflicts of interest regarding the content herein. Manuscript submitted October 22, 2010, provisional acceptance given November 22, 2010, final version accepted February 15, 2011. Address for correspondence: David Zhao, MD, PhD, Vanderbilt University Medical Center, Cardiovascular Medicine, Vanderbilt Heart and Vascular Institute, 1215 21st Avenue S., MCE 5th Floor, Nashville, TN 37232-8802. E-mail: david.zhao@vanderbilt.edu