Low eGFR in cardiogenic shock without CKD indicates hypoperfusion and increased 30-day mortality risk

Background In patients with cardiogenic shock (CS) but without pre-existing chronic kidney disease (CKD), worsening kidney function may provide prognostic information beyond established biomarkers such as serum lactate. Purpose To determine the effect of baseline estimated glomerular filtration rate (eGFR) on short-term mortality across different aetiologies of cardiogenic shock and to evaluate whether kidney dysfunction carries prognostic relevance depending on the underlying cause of CS. Methods Consecutive patients presenting with CS without a prior history of CKD and treated between 2009 and 2019 at a large tertiary cardiovascular centre were retrospectively analysed. Multivariable regression models adjusted for clinically relevant confounders, including age, comorbidities, haemodynamic parameters, and lactate levels, were constructed to assess the association between baseline eGFR and 30-day mortality. Analyses were additionally stratified according to CS aetiology, particularly acute myocardial infarction–related CS (AMI-CS) and heart failure–related CS (HF-CS). Results Among 935 eligible patients (median age 69 years; 269 women [28.8%]; median lactate concentration 4.6 mmol/L; mean eGFR 46.2 ml/min; AMI-CS 50.7%), lower eGFR values were associated with increased 30-day mortality. The risk of death increased by 6% for every 10 ml/min decrease in eGFR (HR 0.94; 95% CI 0.90–0.99; p=0.016). In patients with eGFR at or below the cohort median (41.74 ml/min), this association remained significant only in HF-CS (HR 1.32; 95% CI 1.00–1.73; p=0.047), whereas no significant relationship was observed in AMI-CS (HR 1.03; 95% CI 0.77–1.37; p=0.86). Conclusions In patients with cardiogenic shock without pre-existing CKD, impaired renal function is an independent predictor of increased 30-day mortality even after adjustment for lactate levels. This prognostic effect appears to be primarily driven by patients with HF-CS, in whom myocardial recovery options are limited compared with revascularisation strategies such as PCI in AMI-CS. These findings underscore the importance of rapidly restoring and maintaining end-organ perfusion to prevent irreversible extracardiac organ damage, particularly in HF-CS patients, and suggest that assessment of renal function may aid risk stratification and therapeutic decision-making in this high-risk population.