Letter by Kalavrouziotis et al Regarding Article, "Temporal Trends in Predictors of Early and Late Mortality After Emergency Coronary Artery Bypass Grafting for Cardiogenic Shock Complicating Acute Myocardial Infarction".

Abstract

Circulation. 2017;135:e814–e815. DOI: 10.1161/CIRCULATIONAHA.116.026180 e814 Dimitri Kalavrouziotis, MD, MSc François Dagenais, MD Siamak Mohammadi, MD To the Editor: We read with interest the article by Davierwala et al1 examining early and late survival after coronary artery bypass graft surgery (CABG) in the setting of cardiogenic shock post–acute myocardial infarction (CS-AMI). The improvement in CABG outcomes as reported in this large, single-center experience for CS-AMI is reassuring. The authors hypothesize that improvements in the technical conduct of CABG such as the avoidance of cross-clamping the heart, and increased rates of completeness of revascularization, as well, may explain the improved surgical results in the modern era. Despite a sophisticated analysis in >500 patients, the study design is severely limited by its retrospective nature and the author’s claim of a “beneficial effect of surgical revascularization” in CS-AMI remains speculative. There is no doubt that CABG is superior to percutaneous coronary intervention (PCI) in achieving completeness of revascularization. This is important in that half of patients with ST-segment–elevation myocardial infarction have multivessel disease; in patients with CS-AMI, this percentage increases to 70% to 80%.2 However, the relevance of completeness of revascularization in cardiogenic shock is questionable. In the SHOCK trial (Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock), 30-day and 1-year mortality rates were similar between patients who underwent CABG and those that underwent PCI, despite a significantly higher rate of complete revascularization in the CABG subgroup.3 Although multivessel PCI at the time of culprit-artery revascularization for AMI shows promising results for stable patients,4 there are data suggesting harm in CS-AMI.5 This is not at all surprising given that the major driver of clinical outcome in CS-AMI is end-organ hypoperfusion and its consequences, as corroborated by the lactate subanalysis in the Davierwala et al study, and not the theoretical risk of residual remote myocardial ischemia associated with incomplete revascularization. Furthermore, the authors do not report the proportion of CS-AMI patients who did not undergo CABG and who were directed instead to mechanical circulatory support as a bridge to further therapy such as a durable left ventricular assist device or cardiac transplant. Taken further, it is conceivable that the benefit observed following CABG in CS-AMI in the latter time period of the study was simply attributable to better patient selection and refined treatment allocation, with those patients with the most profound forms of shock treated with mechanical circulatory support as a bridge to recovery, transplant, or durable left ventricular assist device as an alternative to early surgical revascularization. It is becoming increasingly clear that further refinements in the timing and execution of PCI and CABG are unlikely to have a meaningful impact in the prognosis of patients with CS-AMI, which continues to be dismal. Primary PCI and CABG in select patients are, and should, continue to be the cornerstone of the management of the majority of patients with CS-AMI. However, there is an urgent need to investigate alternative treatment modalities to coronary revascularization, such as early institution Letter by Kalavrouziotis et al Regarding Article, “Temporal Trends in Predictors of Early and Late Mortality After Emergency Coronary Artery Bypass Grafting for Cardiogenic Shock Complicating Acute Myocardial Infarction”

DOI: 10.1161/CIRCULATIONAHA.116.026180

Cite this paper

@article{Kalavrouziotis2017LetterBK, title={Letter by Kalavrouziotis et al Regarding Article, "Temporal Trends in Predictors of Early and Late Mortality After Emergency Coronary Artery Bypass Grafting for Cardiogenic Shock Complicating Acute Myocardial Infarction".}, author={Dimitri Kalavrouziotis and François Dagenais and Siamak Mohammadi}, journal={Circulation}, year={2017}, volume={135 13}, pages={e814-e815} }