IABP VS. PERCUTANEOUS LVADS
Intra-aortic balloon pump (IABP) remains the method of choice for mechanical assistance1 in patients experiencing LV failure because of its proven hemodynamic capabilities, prompt time to therapy, and low complication rates. Percutaneous left ventricular assist devices (pLVADs) represent an emerging option for partial or total circulatory support2 and several studies have compared the safety and efficacy of these devices with IABP.
A few randomized controlled trials have demonstrated better hemodynamic profiles for pLVADs compared with IABP. However, this has not translated into improved 30-day survival. Additionally, there was no trend toward a reduced 30-day mortality rate associated with pLVADs. Moreover, patients treated with pLVADs tended to have a higher incidence of leg ischemia and device related bleeding.3 The use of positive inotropic drugs or vasopressors was expected to be lower in patients with pLVADs but no differences have been detected in the overall use of these agents.4, 5
However, pLVADs may increase their use for patients not responding to PCI, fluids, inotropes, and IABP. Therefore, the decision making process on how to treat requires an integrated stepwise approach, although the evidence supporting this is very limited. A pLVAD might be considered on the basis of individual risk, success rates or standard treatment, and potential periprocedural event rates.6
Until an alternative modality, characterized by improved efficacy and safety features compared with IABP, is developed, IABP remains the cornerstone of temporary circulatory support.2
1 Percutaneous LVADs in AMI complicated by cardiogenic shock. H Thiele, et al. EHJ 2007;28:2057-2063
2 Cardiogenic shock current concepts and improving outcomes. H R Reynolds et al. Circulation 2008 ;117 :686-697
3 Percutaneous left ventricular assist devices vs. IABP counterpulsation for treatment of cardiogenic shock. J M Cheng, et al. EHJ doi:10.1093/eurheart/ehp292
4 A randomized clinical trial to evaluate the safety and efficacy of a pLVAD vs. IABP for treatment of cardiogenic shock caused by MI. M Seyfarth, et al. JACC 2008;52:1584-8
5 A randomized multicenter clinical study to evaluate the safety and efficacy of the tandem heart pLVAD vs. conventional therapy with IABP for treatment of cardiogenic shock.
6 Percutaneous LVADs in AMI complicated by cardiogenic shock. H Thiele, et al. EHJ 2007;28:2057-2063
Impella will not demonstrate a significant difference in major adverse events in very high-risk patients when compared to IABP.
Abstract - E P Tsagalou, et al. CHF 2009;15:35-40
Intractable heart failure (HF) remains a leading fatal complication of acute myocardial infarction (AMI). Intra-aortic balloon pump (IABP) counterpulsation assists the failing left ventricle and accelerates the functional recovery of stunned myocardium. Despite its remarkable performance, the beneficial effects of the IABP in the setting of acute HF or cardiogenic shock complicating AMI have not been confirmed in a randomized clinical trial. Instead, large amounts of information have been collected in observational studies or in retrospective analyses of randomized trials of reperfusion strategies in patients with AMI. The strategy of "stabilize with IABP, treat with reperfusion, and transfer for complete revascularization" has, thus far, yielded the best outcomes, and every effort should be made to implement this strategy in all patients presenting with AMI and severe HF.
Abstract - D Burkhoff, et al. AHJ 2006;152:469.e1-469.e8
BACKGROUND & OBJECTOVES: Despite major advances in the treatment of heart failure, cardiogenic shock (CGS) remains associated with substantial mortality. Recent data suggest that the TandemHeart percutaneous ventricular assist device (pVAD) may be useful in the management of CGS. The aim of this prospective randomized study was to test the hypothesis that the TandemHeart (pVAD) provides superior hemodynamic support compared with intraaortic balloon pumping (IABP).
METHODS: Forty-two patients from 12 centers presenting within 24 hours of developing CGS were included in the study and treated in an initial roll-in phase (n = 9) or randomized to treatment with IABP (n = 14) or TandemHeart pVAD (n = 19). Thirty patients (71%) had persistent CGS despite having an IABP in place at the time of study enrollment.
RESULTS: Cardiogenic shock was due to myocardial infarction in 70% of the patients and decompensated heart failure in most of the remaining patients. The mean duration of support was 2.5 days. Compared with IABP, the TandemHeart pVAD achieved significantly greater increases in cardiac index and mean arterial blood pressure and significantly greater decreases in pulmonary capillary wedge pressure. Overall 30-day survival and severe adverse events were not significantly different between the 2 groups.
CONCLUSION: In patients presenting within 24 hours of the development of CGS, TandemHeart significantly improves hemodynamic parameters, even in patients failing IABP. Larger-scale studies are required to assess the influence of improved hemodynamics on survival.
Abstract - M Seyfarth, et al. JACC 2008;52:1584-8
OBJECTIVES: The aim of this study was to test whether the left ventricular assist device (LVAD) Impella LP2.5 (Abiomed Europe GmbH, Aachen, Germany) provides superior hemodynamic support compared with the intra-aortic balloon pump (IABP).
BACKGROUND: Cardiogenic shock caused by left ventricular failure is associated with high mortality in patients with acute myocardial infarction (AMI). An LVAD may help to bridge patients to recovery from left ventricular failure.
METHODS: In a prospective, randomized study, 26 patients with cardiogenic shock were studied. The primary end point was the change of the cardiac index (CI) from baseline. Secondary end points included lactic acidosis, hemolysis, and mortality after 30 days.
RESULTS: Baseline cardiac index (CI) was 1.7 l/min/m2 for both groups. At 4 hours CI was higher with IABP (2.23 l/min) vs. IABP (2.25 l/min). Reversal of serum lactate levels were comparable for both groups. Hemolysis, as measured by free hemoglobin, was significantly higher in Impella patients during the first 24 hours. The Impella patients also required more packed red blood cells and fresh-frozen plasma, while one patient suffered from acute limb ischemia requiring surgery.Overall 30 day mortality was 46% in both groups.
Abstract - J M. Cheng, et al. EHJ doi:10.1093/eurheart/ehp292
OBJECTIVES: Studies have compared safety and efficacy of percutaneous left ventricular assist devices (LVADs) with intra-aortic balloon pump (IABP) counterpulsation in patients with cardiogenic shock. We performed a meta-analysis of controlled trials to evaluate potential benefits of percutaneous LVAD on haemodynamics and 30-day survival.
METHODS & RESULTS: Two independent investigators searched Medline, Embase, and Cochrane Central Register of Controlled Trials for all controlled trials using percutaneous LVAD in patients with cardiogenic shock, where after data were extracted using standardized forms. Weighted mean differences (MDs) were calculated for cardiac index (CI), mean arterial pressure (MAP), and pulmonary capillary wedge pressure (PCWP). Relative risks (RRs) were calculated for 30-day mortality, leg ischaemia, bleeding, and sepsis. In main analysis, trials were combined using inverse-variance random effects approach. Two trials evaluated the TandemHeart and a recent trial used the Impella device. After device implantation, percutaneous LVAD patients had higher CI (MD 0.35 L/min/m2, 95% CI 0.09Ð0.61), higher MAP (MD 12.8 mmHg, 95% CI 3.6Ð22.0), and lower PCWP (MD *5.3 mm Hg, 95% CI *9.4 to *1.2) compared with IABP patients. Similar 30-day mortality (RR 1.06, 95% CI 0.68Ð1.66) was observed using percutaneous LVAD compared with IABP. No significant difference was observed in incidence of leg ischaemia (RR 2.59, 95% CI 0.75Ð8.97) in percutaneous LVAD patients compared with IABP patients. Bleeding (RR 2.35, 95% CI 1.40Ð3.93) was significantly more observed in TandemHeart patients compared with patients treated with IABP.
CONCLUSION: Although percutaneous LVAD provides superior haemodynamic support in patients with cardiogenic shock compared with IABP, the use of these more powerful devices did not improve early survival. These results do not yet support percutaneous LVAD as first-choice approach in the mechanical management of cardiogenic shock.
Abstract - H Thiele, et al. EHJ 2007;28:2057-2063
Cardiogenic shock (CS) remains the most common cause of death in patients with acute myocardial infarction (AMI). In addition to percutaneous coronary intervention, inotropes, and fluids, intraaortic balloon pumping (IABP) is most widely used for initial haemodynamic stabilization. However, the main limitation of IABP is the lack of active circulatory support and the requirement of a certain level of left ventricular (LV) function. In many patients with severe depression of LV function, haemodynamic support and LV unloading derived from IABP is insufficient to reverse CS. The use of percutaneous LV assist devices (LVAD) with active circulatory support might be beneficial in CS patients not responding to standard treatment including IABP support. This review reports the current experience of percutaneous LVAD in CS complicating AMI.