Percutaneous left ventricular assist devices--still waiting for the final word.

Cardiovascular Division, Department of Medicine,University of Miami Miller School of Medicine,Miami, FloridaThe development of temporary percutaneous leftventricular assist devices (TPLVAD) is perceived as animportant step forward in the care of patients with car-diogenic shock and patients with extensive coronaryartery disease, low ejection fraction, and multiplecomorbidities whose only revascularization option ispercutaneous coronary intervention (PCI). The preva-lence of cardiogenic shock has remained stable atapproximately 7% in ST-elevation myocardial infarc-tion over the past 30 years. The mortality remains high(>50%) despite a better understanding of inotropictherapies and widespread use of intraaortic balloonpumps (IABP) [1]. To date, there are only moderate-to-small randomized and observational studies investi-gating TPLVAD, due to the select nature of the targetpopulation, the complexities associated with their useand monitoring, and their high cost.In this issue of the Journal, Froesch et al. [2] presenttheir single center experience with the use of TPLVADin a retrospective analysis of 75 patients with cardio-genic shock (n549) and high risk PCI (n526). Inter-estingly, TandemHeart was more likely to be used incardiogenic shock compared with Impella, which wasmore frequently used to support high-risk PCI. This isnot surprising as TandemHeart can fully support circu-lation in the most extreme cases. The authors reporteda high 6-month mortality of 23% in the high-risk PCIgroup and 55% in the shock group. The overall devicecomplication rate was as high at 36% (more than 1 in3), with a staggering 43% in the shock group. Theseﬁgures may represent selection bias, as operators tendto favor the use of TPLVAD in cases of advanced re-fractory shock with profound hypotension and systemicinﬂammatory response that are unlikely to respond toIABP support.The feasibility of use and superior hemodynamicsassociated with TPLVAD in high-risk PCI aresupported by previous data [3–5]. The recently pre-sented PROTECT II trial, randomized a unique high-risk PCI patient population to IABP versus Impella2.5. After an interim analysis with 324 patients, thetrial was stopped for futility. However, the ﬁnal resultsincluding 447 patients showed an intriguing 21%reduction in major adverse events at 90 days withImpella compared with IABP (40.8% vs 51.4%,p50.029), mostly driven by a decrease in repeat revas-cularization procedures. Impella support provided bet-ter hemodynamic stability during PCI allowing opera-tors to perform longer procedures with more aggressiveuse of rotational atherectomy [6].The survival beneﬁt of TPLVAD over IABP is yetto be established in patients with cardiogenic shock[7]. Previous studies have shown that hemodynamicparameters are consistently improved with TPLVAD[7–10]. The ongoing IMPRESS in STEMI trial, inves-tigating Impella 2.5 versus IABP for large anteriorwall STEMI with high clinical risk, will hopefully pro-vide a more deﬁnitive answer to this question [11].TPLVAD insertion and use is more complex thanIABP. TPLVAD work best in the hands of skilledoperators with expertise in the management of largesize catheters and transseptal puncture for thepositioning of the left atrial cannula in the case ofTandemHeart. In addition, catheterization laboratorypreparedness and well-trained staff are essential for theoptimal use and minimization of complications associ-ated with TPLVAD. Science is replete with exampleswhere proof of concept and expert consensus does notnecessarily translate into clinical beneﬁt. On the otherhand clinical practice is even more replete with exam-ples where inconclusive results do not easily dissuadea steadfast clinician convinced about the beneﬁt of anintervention. The registry data presented in this issueof the Journal provides useful information to betterunderstand the clinical use of TPLVAD [2]. However,