Indications for short- or long-term mechanical circulatory support (MCS) in patients with acute or chronic severe disease, of various degrees of urgency, and with different probabilities of myocardial recovery are presented and discussed in details in other chapters.

Short-term mechanical support is generally a rescue therapy and can be applied in almost all the patients, due to the variety of available devices, some of which can also be implanted percutaneously. The goal is to maintain perfusion and oxygenation, thus gaining time, while hopefully there would be some improvement in myocardial, lung, and end-organ function. The predicted duration goes from days to weeks.

On the other side, long-term mechanical support therapy (most often provided with a left ventricular assist device, LVAD) is now intended for accompanying patients for months to years. Comparing INTERMACS reports published in 2010 and 2015, which include about 1000 and over 15,000 cases, respectively, there is an increasing proportion of patients who received LVAD as permanent treatment (destination therapy, DT) from <10% to >45% and a decreasing 1-year transplant rate, from >50% to 20%, in patients who received LVAD with bridge-to-transplant (BTT) strategy [1, 2]. Currently, indication for LVAD therapy is considered earlier in the course of the disease, in order to avoid the sum of procedure- and device-related adverse events and patient-related risk factors [3]. Despite improvements regarding device duration, portability, user interface, and may be thrombogenicity, relevant morbidity is still associated with long-term LVAD, even when functional improvement without excess mortality is simultaneously obtained [4].

For these reasons, it is recommended to perform a comprehensive patient evaluation before the operation, to assess baseline status, and to identify pre-existing or new comorbid conditions that may influence postoperative survival and the probability of adverse events and complications, or may compromise the expected improvement in functional status and quality of life [5, 6]. In practice, this work-up is similar to what is usually done for HTX candidate selection. As for HTX listing, the border between contraindications, unacceptable or acceptable risk factors is not clear-cut in many situations. However, the objectives of these screening processes are not exactly the same, both in terms of specific goals and of underlying principles. Regarding HTX listing, besides beneficiality versus risk in the individual patient, the best use of a scarce, fixed resource must be taken into account also from the perspective of the community. Another difference with respect to HTX is that in many patients, except those with INTERMACS profile 1 and 2, LVAD implant is an elective or semi-elective procedure. Thus, in most cases, there are some days/weeks for addressing patient-specific risk factors, to minimize their burden on patient outcome or at least to set up in advance a strategy to monitor and approach expected complications. On the contrary, HTX cannot be planned, and generally there is a very short time – if any – for preoperative patient assessment and treatment. This chapter will summarize briefly the preoperative evaluation process before LVAD implantation; then some of the issues that may deserve attention, to reduce the probability of unfavorable outcome and/or complications, will be specifically discussed. The interplay between long-term MCS and HTX is discussed elsewhere (► Chaps. 8, 10, and 13).

◘ Table 5.1 provides a summary of what, ideally, should be done in patients under evaluation prior to long-term LVAD implant [5, 6]. Several aspects are taken into account: prognosis on medical therapy [7–11]; global status, including psychosocial aspects and quality of life [12–15], hemodynamic and morphological aspects [16, 17], kidney and liver function [11], coagulation and hematology [18–20], diabetes, nutritional status [21], respiratory function, peripheral vessels, neurological status, and infections [22]; and screening for cancer or other comorbidities, some of which are discussed later. The depth, extent, and degree of details of preoperative evaluation should be adapted to individual patients’ characteristics, including age, diagnosis, pathophysiological profile, and severity of the clinical picture (◘ Table 5.2). For details, see also ► Chaps. 1, 2, 3, and 5.