The Challenging Diagnosis of Septic Cardiomyopathy

We read with interest the “septic heart” review in the February issue of CHEST.1Martin L. Derwall M. Al Zoubi S. et al.The Septic Heart: current understanding of molecular mechanisms and clinical implications.Chest. 2019; 155: 427-437Abstract Full Text Full Text PDF PubMed Scopus (143) Google Scholar The authors highlight the urgent need for a clear definition of septic cardiomyopathy. The main challenges in this definition are the evaluation of the cardiovascular context (in particular, evaluation of cardiac function in the setting of highly variable preload and afterload conditions), and the lack of longitudinal echocardiography data starting from premorbid heart function with serial echocardiographic evaluations performed during the course of the critical illness and eventually following recovery. We applaud the authors1Martin L. Derwall M. Al Zoubi S. et al.The Septic Heart: current understanding of molecular mechanisms and clinical implications.Chest. 2019; 155: 427-437Abstract Full Text Full Text PDF PubMed Scopus (143) Google Scholar for their efforts and fully endorse the need for a standardized definition of septic cardiomyopathy; however, at present, there are not enough data to support a precise definition of septic cardiomyopathy. The first characteristic proposed by the authors (Table 1) is a combination of left ventricular (LV) dilatation with normal/low filling pressure (LVFP). A dilated left ventricle has increased end-diastolic volume (and, in most cases, end-diastolic pressure). It seems unlikely that well-resuscitated patients with manifestations of septic cardiomyopathy can exhibit a dilated left ventricle without increased LVFP. Indeed, a meta-analysis reported significantly higher ratio of the E wave to e' wave obtained with tissue doppler imaging (E/e' - surrogate of LVFP) in patients with sepsis who were nonsurvivors. However, in the vast majority of the included studies, survivors also had abnormal E/e′ values, confirming the large prevalence of raised LVFP during sepsis.2Sanfilippo F. Corredor C. Arcadipane A. et al.Tissue Doppler assessment of diastolic function and relationship with mortality in critically ill septic patients: a systematic review and meta-analysis.Br J Anaesth. 2017; 119: 583-594Abstract Full Text Full Text PDF PubMed Scopus (81) Google ScholarTable 1Proposed “Main Characteristics” of Septic Cardiomyopathy by Martin et al1Martin L. Derwall M. Al Zoubi S. et al.The Septic Heart: current understanding of molecular mechanisms and clinical implications.Chest. 2019; 155: 427-437Abstract Full Text Full Text PDF PubMed Scopus (143) Google ScholarAcute cardiac dysfunction unrelated to ischemia with one or more of the following:•Left ventricular dilatation with normal-filling or low-filling pressure•Reduced ventricular contractility•Right ventricular dysfunction or left ventricular (systolic or diastolic) dysfunction with a reduced response to volume infusion Open table in a new tab The second proposed criteria—“reduced ventricular contractility”—is generic and incorporated into the third proposed characteristic, which includes a wide spectrum of biventricular dysfunction, with systolic or diastolic abnormalities. In the context of sepsis, it is important to clearly differentiate LV diastolic dysfunction (associated with worse outcomes) from LV systolic dysfunction (which has not shown similar associations3Sanfilippo F, Corredor C, Fletcher N, et al. Diastolic dysfunction and mortality in septic patients: a systematic review and meta-analysis [published correction appears in Intensive Care Med. 2015;41(6);1178-1179]. Intensive Care Med. 2015;41(6):1004-1013.Google Scholar). Accordingly, patients with LV diastolic dysfunction may warrant a careful approach in terms of fluid resuscitation (which should be based not only on indexes of fluid responsiveness), modulation of afterload, and optimization of heart rate.4Sanfilippo F. Scolletta S. Morelli A. Vieillard-Baron A. Practical approach to diastolic dysfunction in light of the new guidelines and clinical applications in the operating room and in the intensive care.Ann Intensive Care. 2018; 8: 100Crossref PubMed Scopus (40) Google Scholar Finally, the authors discussed the potential role of a speckle-tracking echocardiography (STE).1Martin L. Derwall M. Al Zoubi S. et al.The Septic Heart: current understanding of molecular mechanisms and clinical implications.Chest. 2019; 155: 427-437Abstract Full Text Full Text PDF PubMed Scopus (143) Google Scholar As the authors suggest, STE is a promising technique in the context of sepsis. We endorse this idea and note that data were recently reported in support of this technique. Indeed, a meta-analysis found an association between worse LV function as assessed according to STE (global longitudinal strain) and higher mortality in patients with sepsis.5Sanfilippo F. Corredor C. Fletcher N. et al.Left ventricular systolic function evaluated by strain echocardiography and relationship with mortality in patients with severe sepsis or septic shock: a systematic review and meta-analysis.Critical Care. 2018; 22: 183Google Scholar Of course, prior to firm conclusions being made regarding STE, further research is required with large robust studies, keeping in mind that STE parameters are also affected by preload and afterload conditions. The Septic Heart: Current Understanding of Molecular Mechanisms and Clinical ImplicationsCHESTVol. 155Issue 2PreviewSeptic cardiomyopathy is a key feature of sepsis-associated cardiovascular failure. Despite the lack of consistent diagnostic criteria, patients typically exhibit ventricular dilatation, reduced ventricular contractility, and/or both right and left ventricular dysfunction with a reduced response to volume infusion. Although there is solid evidence that the presence of septic cardiomyopathy is a relevant contributor to organ dysfunction and an important factor in the already complicated therapeutic management of patients with sepsis, there are still several questions to be asked: Which factors/mechanisms cause a cardiac dysfunction associated with sepsis? How do we diagnose septic cardiomyopathy? How do we treat septic cardiomyopathy? How does septic cardiomyopathy influence the long-term outcome of the patient? Each of these questions is interrelated, and the answers require a profound understanding of the underlying pathophysiology that involves a complex mix of systemic factors and molecular, metabolic, and structural changes of the cardiomyocyte. Full-Text PDF ResponseCHESTVol. 156Issue 3PreviewWe thank Dr Sanfilippo and colleagues for their comments on our review summarizing the current understanding of molecular mechanisms and clinical implications of septic cardiomyopathy.1 We fully agree with the authors that one of the main challenges in the definition of septic cardiomyopathy is the evaluation of cardiac function in the setting of highly variable preload and afterload conditions, as well as the lack of longitudinal echocardiography data starting from premorbid heart function. Full-Text PDF