Time interval from symptom onset to hospital care in patients with acute heart failure: A report from the Tokyo cardiac care unit network emergency medical service database

Aims: There seems to be two distinct patterns in the presentation of acute heart failure (AHF) patients; early - vs. gradual-onset. However, whether time-dependent relationship exists in outcomes of patients with AHF remains unclear. Methods: The Tokyo Cardiac Care Unit Network Database prospectively collects information of emergency admissions via EMS service to acute cardiac care facilities from 67 participating hospitals in the Tokyo metropolitan area. Between 2009 and 2011, a total of 3811 AHF patients were registered. The documentation of symptom onset time was mandated by the on-site ambulance team. We divided the patients into two groups according to the median onset-to-hospitalization (OH) time for those patients (2h); early- (presenting <2h after symptom onset) vs. gradual-onset (late) group (>2h). The primary outcome was in-hospital mortality. Results: The early OH group had more urgent presentation, as demonstrated by a higher systolic blood pressure (SBP), respiratory rate, and higher incidence of pulmonary congestion (48.6% vs. 41.6%; P<0.001); whereas medical comorbidities such as stroke (10.8% vs. 7.9%; P<0.001) and atrial fibrillation (30.0% vs. 26.0%; P<0.001) were more frequently seen in the late OH group. Overall, 242 (6.5%) patients died during hospitalization. Notably, a shorter OH time was associated with a better in-hospital mortality rate (odds ratio, 0.71; 95% confidence interval, 0.51-0.99; P = 0.043). Conclusions: Early-onset patients had rather typical AHF presentations (e.g., higher SBP or pulmonary congestion) but had a better in-hospital outcome compared to gradual-onset patients.