A single-centre prospective, cohort study of the natural history of acute pancreatitis.

Background: The natural history of acute pancreatitis is based on clinical studies that aim to elucidate the course of disease on the basis of predicted risk factors.

Aims: To evaluate the long-term occurrence of recurrent acute pancreatitis and chronic pancreatitis in a cohort of patients following an initial episode of acute pancreatitis.

Methods: 196 patients were enrolled consecutively and studied prospectively. Clinical characteristics, exogenously/endogenously-associated factors, and evolution to recurrent acute pancreatitis and chronic pancreatitis were analyzed.

Results: 40 patients developed recurrent acute pancreatitis 13 of whom developed chronic pancreatitis. In a univariate analysis, recurrent acute pancreatitis was associated with an idiopathic aetiology (p<0.001), pancreas divisum (p=0.001), and higher usage of cigarettes and alcohol (p<0.001; p=0.023). Chronic pancreatitis was associated with a severe first episode of acute pancreatitis (p=0.048), PD (p=0.03), and cigarette smoking (p=0.038). By multivariate analysis, pancreas divisum was an independent risk factor for recurrent acute pancreatitis (OR 11.5, 95% CI 1.6-83.3). A severe first-episode of acute pancreatitis increased the risk of progressing to chronic pancreatitis by nine-fold.

Conclusions: Special attention should be given to patients who experience a severe first attack of acute pancreatitis as there appears to be an increased risk of developing chronic pancreatitis over the long term.