Objective To evaluate the effects of spironolactone on cardiac sympathetic nerve activity (CSNA) and left ventricular (LV) remodelling in patients with ST-segment elevation myocardial infarction (STEMI).

Design Single-centre, prospective, randomised evaluation study.

Setting Patients with a first STEMI and single-vessel disease undergoing primary coronary angioplasty.

Patients Sixty patients randomly assigned to two groups before angioplasty.

Interventions Patients were randomly assigned to receive or not the spironolactone before primary coronary angioplasty.

Main outcome The extent score (ES) was determined by use of ^99mTc-pyrophosphate scintigraphy to evaluate the area of initial myocardial damage 3–5 days after primary angioplasty. The LV end-diastolic volume (LVEDV), LV end-systolic volume (LVESV) and LV ejection fraction were determined by echocardiography, and plasma procollagen type III aminoterminal peptide (PIIINP) was measured before and 3 weeks after treatments. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate (WR) were determined from ¹²³I-meta-iodobenzylguanidine scintigraphy after 3 weeks.

Results After primary angioplasty, age, gender, risk factors, culprit coronary artery, peak serum creatine kinase concentration, recanalisation time and ES were similar in the two groups. However, in the spironolactone group, the TDS and WR were significantly lower (TDS: mean (SD) 22.5 (8.0) vs 29.5 (10.1), p<0.005, WR: 30.5 (8.7)% vs 40.0 (10.9)%, p<0.001) and the H/M ratio was significantly higher (2.18 (0.37) vs 1.96 (0.30), p<0.05) than in the non-spironolactone group. Moreover, significant correlations were found between the degree of change in PIIINP concentration and change in LVEDV (r=0.559, p=0.001), or LVESV (r=0.546, p=0.002) in the spironolactone group.

Conclusion Administration of spironolactone improves CSNA and prevents LV remodelling in patients with a first STEMI.