Patients in cardiogenic shock (CS) have been reported to have a 30-day inhospital mortality between 30% and 50%.1 Multiple predictors of mortality have been described for CS, such as advanced age, diabetes (DM), lactate concentration, advanced stage according to the Society for Cardiovascular Angiography and Intervention (SCAI) classification, and acute kidney failure, among others.2,3

Additionally, patients with chronic heart failure or acute coronary syndrome and poor nutritional status (NS) are known to have poorer prognosis than patients with adequate NS.4

Because of its simplicity, the Controlling Nutritional Status (CONUT) scale is commonly used to evaluate the NS of patients with cardiovascular disease. This scale is based on serum albumin (≥ 3.5g/dL [0 points], 3-3.49g/dL [2 points], 2.5-2.9g/dL [4 points], <2.5g/dL [6 points]), lymphocytes (≥ 1600mm3 [0 points], 1200-1599mm3 [1 point], 800-1199mm3 [2 points], <800mm3 [3 points]), and total cholesterol (> 180mg/dL [0 points)], 140-180mg/dL [1 point], 100-139mg/dL [2 points], <100 mg/dL [3 points]). The sum of these scores is then used to classify nutritional status as normal (0-1) or as light (2-4), moderate (5-8), or severe undernutrition (9-12).5,6

To date, no study has explored the influence of undernutrition on the prognosis of patients in CS. The aim of this study was to assess the role of undernutrition in the prognosis of CS, using the CONUT scale.

The study protocol was approved by the local ethics committee, and the study was conducted in accordance with the Declaration of Helsinki. An informed consent exemption was approved in view of the retrospective and observational design of the study.

The analysis included data for 93 consecutive patients hospitalized between 2016 and 2023 due to CS secondary to acute myocardial infarction. Patients’ baseline characteristics are listed in table 1.

Overall mortality was 48.39%, and 30-day mortality was 32.97%. Patients were classified by severity according to the SCAI scale (B [4.3%], C[55.91%], D (23.66%), and E [16.13%]), and the CONUT score was calculated as described by Ulíbarri et al.6 A normal NS was seen in 23.66% of patients, with light undernutrition observed in 35.48%, moderate in 35.48%, and severe in 5.38% of patients. As NS worsened, shock severity increased (ANOVA test, P<.001) (figure 1A).

Figure 1.

A: association between shock severity according to the Society for Cardiovascular Angiography and Intervention (SCAI) classification and nutritional status according to the Controlling Nutritional Status (CONUT) scale. B: Kaplan-Meier curves comparing survival in patients with normal nutritional status versus light undernutrition (CONUT <5) and moderate or severe undernutrition (CONUT ≥ 5). C: Kaplan-Meier curves comparing survival between the various nutritional statuses. 95%CI, 95% confidence interval; HR, hazard ratio.

(0.24MB).

A total of 98.9% of patients underwent revascularization; of these, percutaneous coronary intervention was performed in 88.17% and fibrinolysis±rescue percutaneous coronary intervention in 11.83%. There were no differences in survival between the 2 groups (P=.72).

The optimal cut-off point for predicting mortality using the CONUT scale was determined using receiver operating characteristic (ROC) curves (5 points; area under the curve=0.71; 95% confidence interval [95%CI], 0.61-0.8; sensitivity=57.8%; specificity=75%). The CONUT score was also shown to be associated with 30-day mortality by a Cox regression analysis (figure 1B). A total of 38 patients (40.86%) had CONUT ≥ 5 points. These patients had worse kidney function (creatinine 2.53mg/dL versus 1.46mg/dL; P<.001) as well as a trend toward higher lactate and aspartate aminotransferase, worse low blood pressure, and stronger likelihood to require orotracheal intubation (OTI) (the differences in baseline and clinical characteristics of both groups are shown in table 1).

The 30-day survival was analyzed using the Kaplan-Meier method, and the groups were compared by a log-rank test. The optimal cut-off point for predicting mortality was determined by ROC curves using creatinine (1.32 mg/dL), lactate (3.96 mmol/L), age (72 years), high-sensitivity troponin T (6.425 pmol/L), and vasoactive–inotropic score (VIS) (45.3). A univariate Cox model was used to analyze the association of these variables (along with left ventricular ejection fraction <30%, SCAI D or E, and DM) with 30-day mortality. The variables were then introduced into a multivariate (backward stepwise) Cox model, identifying the following independent predictors of mortality: CONUT score ≥ 5 (hazard ratio [HR],2.54; 95%CI, 1.14-5.67; P=.023), SCAI stage D or E (HR,5.03; 95%CI, 1.99-12.74; P=.001), lactate ≥ 3.96 mmol/L (HR,6.72; 95%CI, 1.56-28.88; P=.01), high-sensitivity troponin T ≥ 6.425pmol/L (HR,5.31; 95%CI, 1.22-23.11; P=.026), and a history of DM (HR,2.77; 95%CI, 1.31-5.87; P=.008).

As NS worsened, mortality increased significantly (normal NS, 9.1%; light undernutrition, 22.58%; moderate undernutrition, 51.52%; severe undernutrition, 80%; log-rank test, P<.001) (figure 1C).

The results of the study showed the influence of NS on the prognosis of patients in CS; notably, more than 75% of them had an inadequate NS on admission. The association observed between worse NS on admission and shock severity (SCAI) is at least partly explained by the more pronounced kidney function impairment of patients with CONUT ≥ 5, as well as by the trend toward higher lactate and liver enzymes and low blood pressure, all parameters determining shock severity. The potential for early correction of NS to improve CS prognosis is a hypothesis that should be explored in future studies, as it could represent a new pathway to optimizing survival in a group of patients with very high mortality.

This study had several limitations. Because of the retrospective observational nature of the study, causal relationships could not be identified. The study sample was also small; hence, further studies with stronger evidence levels and larger samples are needed to confirm these results. Last, the parameters used in the CONUT scale may also be influenced by inflammation in patients in critical condition. Nevertheless, inflammation is also present in undernutrition, and other studies with patients in critical condition due to other causes (sepsis, trauma, COVID-19) have reported results consistent with our findings.