Background The prognostic role of diabetes mellitus (DM) in elderly patients with myocardial infarction-related cardiogenic shock (MI-CS) remains controversial. Little information exists about the impact of intensive cardiac care unit (ICCU) and revascularization on outcomes of elderly patients with MI-CS. We aimed to assess the prognostic impact of DM according to age in patients with MI-CS, and to analyze the impact ICCU management and revascularization on in-hospital mortality in MI-CS patients at older ages.
Methods Discharge episodes with diagnosis of CS associated with MI were selected from the Spanish National Health System's Basic Data Set. Centers were classified according to their availability of ICCU. Main outcome measured was in-hospital mortality.
Results A total of 23, 590 episodes of MI-CS were identified, of whom 12, 447 (52.8%) were in patients aged ≥ 75 years. The impact of DM on in-hospital mortality was different among age subgroups. While in younger patients, DM was associated to a higher mortality risk (0.52 vs. 0.47, OR = 1.12, 95% CI: 1.06-1.18, χ2 < 0.001), this association became non-significant in older patients (0.76 vs. 0.81, χ2 = 0.09). Adjusted mortality rate of MI-CS aged ≥ 75 years was lower in patients admitted to hospitals with ICCU (adjusted mortality rate: 74.2% vs. 77.7%, P < 0.001) and in patients undergoing revascularization (74.9% vs. 77.3%, P < 0.001).
Conclusions Prognostic impact of DM in patients with MI-CS was different according to age, with a significantly lower impact at older ages. The availability of ICCU and revascularization were associated with better outcomes in these complex patients.