Objective acid exposure links to cardiac polyps: insights from 24-hour MII-pH monitoring and esophageal manometry

AIM: The etiology of cardiac polyps remains debated. Previous studies have primarily relied on symptomatic and endoscopic findings, lacking objective evidence of gastroesophageal reflux. We aimed to investigate the relationship between pathologic acid exposure and cardiac polyps based on 24-hour multichannel intraluminal impedance-pH monitoring (24h MII-pH) and high-resolution esophageal manometry (HREM). METHODS: This retrospective cross-sectional study enrolled patients who underwent upper endoscopy, 24h MII-pH and HREM examination. Clinical, endoscopic, and physiological parameters were compared between cardiac polyp and control group. Logistic regression was used to analyze the association between acid exposure time and cardiac polyps. RESULTS: A total of 123 patients (37 in the polyp group, 86 in the control group) were included. Acid exposure time were significantly elevated, while lower esophageal sphincter resting pressure was lower in the polyp group. After adjusting for confounders, each 1% increase in acid exposure time was associated with a 25% higher risk of cardiac polyps. Patients with acid exposure time >6% had a 3.7-fold increased risk compared to those with acid exposure time <4%. Pathological acid exposure was associated with cardiac polyps in populations with low LES resting pressure and without H. pylori infection. CONCLUSION: This study is the first to objectively demonstrate an independent positive correlation between acid exposure time and cardiac polyps particularly in H. pylori-negative patients and those with esophageal motility disorders, but causal relationships cannot be established. These findings provide new insights into the pathogenesis of cardiac polyps and suggest a potential role for acid-suppressive therapy in selected patients.