A total of 207 acute patients who showed primary symptoms of STEMI and successfully underwent emergent PCI treatment during hospitalization in the Department of Cardiology of Xuzhou Central Hospital (Jiangsu, China) from December, 2012 to December, 2014, were randomly divided into two groups of dual antiplatelet therapy (aspirin plus clopidogrel). The test group (PPIs), which received co-treatment of aspirin and clopidogrel and pantoprazole, comprised 123 patients (69 men and 54 women), with an average age of 59.32±9.14 years. The control group (treatment with aspirin and clopidogrel), comprised 84 patients (48 men and 36 women), with an average age of 58.47±10.06 years.

The selected patients adhered to the WHO diagnostic criteria of STEMI: i) typical chest pain duration of >30 min; ii) ST-segment elevation in electrocardiogram in the lead of at least two limbs or two precordial leads >1 mm; and iii) dynamic changes in serum cardiac enzymes with surgery indications for emergent PCI. Exclusion criteria for the patients were: i) with other heart diseases; ii) with severe heart failure (Killip grade III–IV) and liver and kidney dysfunction; iii) combined with acute and chronic infections, gastrointestinal ulcers, blood diseases, malignancies, rheumatic connective tissue diseases and other immune system disorders; iv) with recent surgery or trauma with previous PCI surgery; v) with diabetes and other endocrine diseases; and vi) with cerebrovascular and peripheral vascular diseases and other diseases.

Immediately after admission the patients received (before PCI) aspirin tablets (500 mg) by chewing and clopidogrel orally at a loading dose of 600 mg. The patients were then postoperatively administered clopidogrel at a dose of 75 mg and Bayer aspirin (Yangtze River Pharmaceutical Co., Ltd., Taizhou, China) at 100 mg, both by oral administration, daily, and enoxaparin sodium was used concomitantly for 5 to 8 days.

Patients in the PPIs group were treated with intravenous injection of pantoprazole at 40 mg immediately after admission for 3 to 5 days, on a daily basis. followed by oral administration at 40 mg, daily, until discharge.

Patients showing relevant indications during hospitalization received statins, β-blockers and angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) or other medicine for the treatment.

Gastrointestinal bleeding was observed in the two groups during hospitalization. A gastrointestinal ulcer due to stress was identified from one of the following signs especially during the first week of hospitalization: vomit; brown, red or black gastric juice, or bloody stool; black stool in parallel with positive result of occult blood test; unexplained decline in hemoglobin (5); and recessive bleeding without the abovementioned signs: positive results only in occult blood test, no significant bleeding; severe gastrointestinal bleeding: obvious vomiting of blood, bloody stool or sharp decline of hemoglobin; minor bleeding: bleeding between recessive and gastrointestinal bleeding.

During the first 6 months of illness (including the hospitalization period), the major adverse cardiac events (MACEs) of the two groups were recorded, including secondary onset of heart failure, severe arrhythmias (ventricular tachycardia, ventricular fibrillation, atrioventricular block at degree II or above III), infarction after angina, recurrent myocardial infarction, and cardiac death.

SPSS 18.0 (Chicago, IL, USA) software was used for statistical analysis. Measurement data are presented as mean ± standard deviation and the countable data were analyzed using the Chi-square test (χ²). P<0.05 was considered statistically significant.

There were no statistically significant differences (p>0.05) for gender, age, body mass index (BMI), smoking, drinking history, concomitant diseases (hypertension, hyperlipidemia), and the biochemical criteria (blood routine examination, coagulation function, biochemistry full terms) of patients between the PPIs and control groups.

Gastrointestinal bleeding occurred in two cases (1.6%) of the PPIs group, including one case of occult bleeding and one case of minor bleeding, without severe gastrointestinal bleeding in this group. Additionally, there were 13 cases of gastrointestinal bleeding in the control group (15.5%), including 5 cases of recessive bleeding, 5 cases of minor bleeding and 3 cases of severe gastrointestinal bleeding. There were significant differences (p<0.05) between the PPIs and control groups (Table I).

There were no statistical differences in the secondary onset of heart failure, severe arrhythmias (ventricular tachycardia, ventricular fibrillation, atrioventricular block at degree II or above III), infarction after angina, and recurrent myocardial infarction, as well as cardiac death in patients between two groups (all at p>0.05), (Table II).