Background

Coronary heart disease remains the leading cause of mortality [1]. Prevention of in-hospital death is a crucial step in improving prognosis of patients with ST elevation myocardial infarction (STEMI). We want to investigate the risk factors of in-hospital death.

Methods

Source of data

Totally 9668 patients with acute STEMI in Beijing Anzhen Hospital, Capital Medical University from January 2002 to August 2019.

Inclusion criteria: (1) patient hospitalized with STEMI; (2) age of more than 18 years.

We established the diagnosis of acute myocardial infarction (AMI) and STEMI base on fourth universal definition of myocardial infarction [2].

Exclusion criteria: none.

Evaluation and diagnosis of in-hospital death

All causes for in-hospital death is defined as cardiac or non-cardiac death during hospitalization.

Predictors

We selected 11 predictor variables for inclusion in our prediction rule. They were shown in Table 1. PCI = percutaneous coronary intervention, CABG = coronary artery bypass grafting. Atrial fibrillation is defined as all type of atrial fibrillation during hospitalization. Atrioventricular block is defined as all type of atrioventricular block during hospitalization.

Table 1 Clinical characteristics of patients with in-hospital death and in-hospital survivors
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Statistical analysis

We followed the methods of Li et al. 2019 [3].

Results

Participants and predictors of in-hospital death

Totally 188 patients had in-hospital death (in-hospital death group) and 9480 patients had no in-hospital death (control group). The results are shown in Table 1.

Predictors of in-hospital death

Eight variables (age, gender, history of myocardial infarction, history of hypertension, Killip classification, atrial fibrillation, atrioventricular block, and underwent PCI during hospitalization) were significant differences in the two groups of patients (p < 0.05). After application of backward variable selection method, three variables (underwent PCI, age, and Killip classification) remained as significant independent predictors of in-hospital death. Results are shown in Tables 2 and 3.

Table 2 Predictor of in-hospital death obtained from multivariable logistic regression models (odds ratio)
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Table 3 Predictor of in-hospital death obtained from multivariable logistic regression models (Coef)
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We drew the receiver operating characteristic curve. The area under the receiver operating characteristic curve was 0.94 ± 0.007, 95% CI = 0.926–0.954.

Study limitations

This is a single-center experience. Some patients were enrolled > 10 years ago, thus their treatment may not conform to current standards and techniques.

Discussion

We investigated the predisposing factors of in-hospital death. A frequency of in-hospital death was 1.9% (188/9668). Killip classification is an independent risk factor of in-hospital death. In our study, patients with Killip class IV were at 64.7 higher risk of in-hospital death than patients with Killip class I–III. Not underwent PCI is an independent risk factor of in-hospital death. Patients who do not get successful reperfusion are at higher risk of early complications and death [4]. Age is an independent risk factor of in-hospital death. Older patients have more comorbidities and are less likely to receive reperfusion therapy [5, 6]. Elderly patients are also at particular risk of bleeding [4].

Conclusions

Age, not underwent PCI during hospitalization, and Killip classification are independent risk factors for predicting in-hospital death in patients with acute STEMI.