Risk factors for sudden cardiac arrest in patients with ST-segment elevation myocardial infarction: a retrospective cohort study.

BACKGROUND: Sudden cardiac arrest (SCA) is a critical complication of acute myocardial infarction, especially ST-segment elevation myocardial infarction (STEMI). This study identified the risk factors for SCA in patients with STEMI before receiving catheterization. METHODS: We retrospectively analyzed the data of patients with STEMI and cardiac arrest who presented to a tertiary care center in Taiwan between January 1, 2016, and December 31, 2019. Only patients with coronary artery disease (CAD) confirmed by coronary angiography were included in this study. We collected the patients' demographic and clinical data, such as age, sex, medical history, estimated glomerular filtration rate (eGFR), and coronary angiographic findings. The primary outcome of this study was SCA in patients with STEMI. Continuous and nominal variables were compared using the two-sample Student's t-test and chi-squared test, respectively. The results of logistic regression were subjected to multivariate analysis with adjustment for possible confounders. RESULTS: A total of 920 patients with STEMI and coronary angiography-documented CAD and 108 patients with SCA who presented between January 1, 2016, and December 31, 2019, were included. The bivariate logistic regression analysis of patients' demographic data revealed that patients with STEMI and SCA were slightly younger, were more likely to have diabetes mellitus, and had a lower eGFR than did the patients without SCA. The coronary angiographic findings indicated a higher prevalence of left main CAD and three-vessel disease in patients with SCA than in patients without SCA. Multivariate logistic regression revealed that left main CAD (odds ratio [OR]: 3.77; 95% confidence interval [CI], 1.84 to 7.72), a lower eGFR (OR: 0.97; 95% CI, 0.96 to 0.98), and younger age (OR: 0.98; 95% CI, 0.96 to 0.99) were the risk factors for SCA in patients with STEMI. CONCLUSIONS: Left main CAD, lower eGFR, and younger age are the risk factors for cardiac arrest in patients with acute myocardial infarction.

Prognostic value of early and late spontaneous conversion into a shockable rhythm for patients with out-of-hospital cardiac arrest.

BACKGROUND: The prognostic significance of conversion into a shockable rhythm in patients who experienced out-of-hospital cardiac arrest (OHCA) with an initially nonshockable rhythm is controversial, perhaps due to the timing of rhythm conversion not being considered previously. We aimed to compare the different prognoses of patients with OHCA and early and late conversion of their rhythm into a shockable rhythm. METHODS: This was a single-centre retrospective cohort study. We enrolled patients with OHCA who were sent to a medical centre in central Taiwan from 2016 to 2020. Patients <18 years old, those with cardiac arrest due to trauma or a circumstantial cause, and those for whom resuscitation was not attempted were excluded. Patients were divided into two groups in accordance with presentation with an initially shockable rhythm. Those with an initially nonshockable rhythm were divided into three subgroups: early-conversion, late-conversion, and nonconversion groups. The primary outcome was the neurological functional status upon discharge from hospital. RESULTS: A total of 1645 patients with OHCA were included: initially shockable rhythm group, 339; early conversion group, 68; late-conversion group, 166; and nonconversion group, 1072. After adjustment, multivariate logistic regression revealed that a favourable neurological outcome was more common in the early conversion group than the nonconversion group (odds ratio [OR] 2.4; 95% confidence interval [CI], 1.1-5.3; p = 0.035), whereas the late-conversion group did not significantly differ from the nonconversion group (OR 0.5; 95% CI, 0.1-1.5; p = 0.211). The proportions of sustained return of spontaneous circulation and survival to discharge were also higher in the early conversion group than the late-conversion group (OR 2.9 95% CI 1.6-5.5, p = 0.001 and OR 4.5, 1.8-11.0, p = 0.001, respectively). CONCLUSION: In patients who experience OHCA and have an initially nonshockable rhythm, early conversion into a shockable rhythm resulted in a better prognosis, whereas late conversion was not significantly different from nonconversion.