The treatment of cardiogenic shock has undergone major changes over the past decades, largely driven by the development and adoption of mechanical circulatory support devices.

Following publication of the IABP-SHOCK II trial, which failed to demonstrate a mortality reduction with intra-aortic balloon pump use in patients with acute myocardial infarction and cardiogenic shock, guideline recommendations changed and its use declined substantially. At the same time, the use of other percutaneous mechanical circulatory support devices and extracorporeal membrane oxygenation (ECMO) has progressively increased. However, most patients included in IABP-SHOCK II underwent percutaneous revascularization, whereas only a small proportion were treated with bypass surgery. This raises the question of whether those conclusions can be directly applied to surgical patients.

Within this context, a retrospective observational study was conducted using data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. A total of 34.015 patients with recent acute myocardial infarction complicated by cardiogenic shock who underwent coronary artery bypass grafting between 2011 and 2022 were included.

The aim was to assess temporal trends in mechanical circulatory support use and its association with clinical outcomes. The primary endpoint was operative mortality, defined as in-hospital death or death within 30 days after surgery. Secondary endpoints included stroke, any reoperation, reoperation for bleeding, postoperative renal failure, and need for dialysis. Clinical characteristics, surgical variables, and timing of device implantation were analyzed, including preoperative, intraoperative, and postoperative support. Factors associated with support use and mortality were evaluated using multivariable logistic regression.

Overall operative mortality was 20.9%, with a significant decline over time, from 24.2% in 2011 to 19.0% in 2022 (p < .001). The intra-aortic balloon pump was the most commonly used device. It was used preoperatively in 70.1% of patients, although its use decreased from 74.6% in 2011 to 64.6% in 2022. By contrast, percutaneous mechanical circulatory support devices increased progressively, from 1.3% to 11.3% over the same period. ECMO was used less frequently, although it also showed an upward trend. In the adjusted analysis, preoperative balloon pump use was associated with lower mortality. In contrast, the use of percutaneous support and ECMO was associated with higher mortality.

The authors conclude that mortality among patients with myocardial infarction and shock undergoing coronary surgery has declined over the last decade. In addition, intra-aortic balloon pump use has decreased, whereas percutaneous support devices have become more frequently used.

COMMENTARY:

This study provides an updated view of cardiogenic shock management in patients undergoing coronary artery bypass grafting, a setting that remains poorly represented in randomized clinical trials.

The progressive reduction in operative mortality is the most relevant finding. It seems reasonable to assume that this decline is multifactorial and related to improvements in systems of care, accumulated experience, and the implementation of multidisciplinary shock teams, rather than solely to the introduction of any specific device.

It is striking that the intra-aortic balloon pump continues to be the most commonly used device in surgical practice and, moreover, is associated with lower adjusted mortality. This finding contrasts with the results of the IABP-SHOCK II trial, which evaluated balloon pump use in the setting of percutaneous coronary intervention. This suggests that the pathophysiology and clinical profile of surgical patients may differ from those of patients treated with angioplasty, thereby limiting direct extrapolation of results between the 2 settings.

The progressive increase in the use of percutaneous devices and ECMO reflects a shift in therapeutic strategies. However, these devices are more often used in patients with greater clinical severity, which makes it difficult to draw firm conclusions regarding their effect on survival. The observed association with higher mortality is most likely driven by the greater baseline severity of these patients.

Among the main limitations are the retrospective nature of the study, the absence of detailed hemodynamic data, and the lack of specific information on the different devices used and the protocols followed at each center.

Despite this, the study provides valuable real-world evidence and reinforces the concept that the surgical patient with cardiogenic shock represents a distinct clinical entity, warranting further dedicated investigation.

REFERENCE:

An KR, Harik L, Rahouma M, Caldonazo T, Habib RH, Dhingra NK, et al. Trends and Outcomes of Mechanical Circulatory Support in Acute Myocardial Infarction and Cardiogenic Shock Patients Undergoing Coronary Artery Bypass Grafting. Ann Thorac Surg. 2026 Jan;121(1):223-230. doi: 10.1016/j.athoracsur.2025.09.022.