Aim : To determine whether symptomatic response to lansoprazole predicts abnormal acid reflux in endoscopy-negative patients with non-cardiac chest pain.

Methods : Patients who complained of chest pain, but had normal coronary angiography, were asked to undergo upper endoscopy. Those without gastric and oesophageal lesions were recruited for 24-h ambulatory oesophageal pH monitoring, and were randomly given lansoprazole 30 mg or placebo, both daily for 4 weeks. Chest pain symptoms were recorded before and 1 month after treatment on a locally validated questionnaire. The symptom score was calculated by multiplying the severity and frequency of the symptom, and symptom improvement was defined as > 50% reduction in symptom score.

Results : Overall, 68 patients, 36 on lansoprazole and 32 on placebo, completed the trial. The symptom score was reduced significantly in both groups (P < 0.001). In the lansoprazole group, more patients with than without abnormal reflux showed symptom improvement (92% vs. 33%; odds ratio = 22; 95% confidence interval, 2.3–201.8; χ2 = 10.9; P = 0.001), giving a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 92%, 67%, 58%, 94% and 75%, respectively. In the placebo group, the rates of symptom improvement were similar between those with and without abnormal reflux (33% vs. 35%, P = N.S.).

Conclusions : Treatment with lansoprazole is a useful test in diagnosing endoscopy-negative gastro-oesophageal reflux disease in Chinese patients with non-cardiac chest pain.