Delay in Hospitalization Raises Risk of All-Cause Mortality in Patients with NSTEMI
Patients with ST-segment elevation myocardial infarction (STEMI) failing to obtain immediate medical care face a significant risk of dying of early malignant arrhythmias or of developing heart failure, cardiogenic shock, or mechanical complications. These complications are less frequent in ST-segment elevation myocardial infarction (NSTEMI) patients, in whom an expected adverse effect of a late diagnosis is an increased risk of recurrent ischemia due to the delay in starting antithrombotic therapy and providing revascularization.
However, a recent study suggests that prehospital delay is associated with an increased risk of 3-year all-cause mortality in NSTEMI patients. The study findings were published in the Journal of the American College of Cardiology on January 24, 2022.
Recently, due to pandemics, patients decreased their visits to hospitals despite having symptoms due to concerns about nosocomial infection. This results in a reduced number of patients presenting with NSTEMI and an increased mortality rate. While several studies have analyzed the consequences of delayed hospital admission in STEMI patients, little is known regarding the potential influence of a late presentation on clinical outcomes in those with NSTEMI. Therefore, Jung-Joon Cha and his team conducted a study to investigate the association between prehospital delay and clinical outcomes in patients with NSTEMI.
For this study, the researchers included 6,544 patients with NSTEMI from the Korea-Acute-Myocardial-Infarction-Registry-National Institutes of Health (KAMIR-NIH). They further categorized patients into two groups based on their symptom-to-door (StD) times—less than 24 hours or 24 hours or more (27.9%). The major outcome assessed was 3-year all-cause mortality. The researchers also assessed a 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure.
Key findings of the study:
- Upon analyzing over a median 1,098-days follow up, the researchers found that patients with a ≥24 hour StD time had higher all-cause mortality compared with those with a time of <24 hours.
- They noted that the composite of all-cause mortality, recurrent MI, and hospitalization for heart failure are higher in patients with a ≥24 hour StD time.
- They also noted that all-cause mortality results were unchanged in subgroup analyses by age, sex, atypical chest pain, dyspnea, Q-wave in the electrocardiogram, use of emergency medical services (EMS), hypertension, diabetes, chronic kidney disease, LV dysfunction, TIMI flow, and GRACE score.
- Upon multivariate analysis, they found that older age, female sex, no EMS use, diabetes, and nonspecific symptoms like atypical chest pain or dyspnea were independent predictors of prehospital delays.
The authors concluded, "Prehospital delay is associated with an increased risk of 3-year all-cause mortality in patients with NSTEMI."
In an accompanying editorial, Dr José A. Barrabés wrote, "This study underscores the importance of seeking urgent medical attention (preferably by contacting the emergency medical services) in the presence of any symptoms suggestive of myocardial ischemia and confirms some variables related to long symptom-to-door times. Future studies addressing in-depth the characteristics associated with a late presentation in NSTEMI, especially the potential barriers of the health care system associated with a prolonged admission delay, are needed to improve the prognosis of these patients."
For further information:
Cha J-J, Bae S, Park D-W, et al. Clinical outcomes in patients with delayed hospitalization for non–ST-segment elevation myocardial infarction. J Am Coll Cardiol. 2022;79:311-323.
