New-onset atrial fibrillation in patients with pneumococcal pneumonia. Impact of timing and duration on short- and medium-term mortality.: New-onset atrial fibrillation and pneumonia.

OBJETIVES: To assess the incidence, related factors, timing and duration of new- onset atrial fibrillation in a cohort of consecutive patients diagnosed with pneumococcal pneumonia.

METHODS: Observational study including all immunocompetent adults hospitalized for pneumococcal pneumonia. Patients were classified by time (atrial fibrillation recognized on emergency room arrival or developed during hospitalization) and duration (paroxysmal or persistent). Patients were followed-up for 6 months after discharge.

RESULTS: We included 1092 patients, of whom 109 (9.9%) had new-onset atrial fibrillation. An early event was documented in 87 (79.8%) cases. Arrhythmia was classified as paroxysmal in 78 patients. Older age, heavy drinking, respiratory rate ≥ 30/minute, leukopenia, severe inflammation and bacteremia were independent risk factors for developing new-onset atrial fibrillation on admission. Overall, 48 (4.4%) patients died during hospitalization, the rate being higher in those patients who developed new-onset arrhythmia (17.9% vs 2.9% p<0.001). Among patients with events recognized at admission, in-hospital mortality was higher in those with persistent arrhythmia (34.8% vs 6.3%, p= 0.002) and 6-month survival was better among those who developed paroxysmal event.

CONCLUSIONS: The development of new-onset atrial fibrillation was associated with pneumonia severity, and higher in-hospital mortality. Bacteremia and severe systemic inflammation were factors associated with its development.