Between November 1985 and January 1994, 4832 patients with rheumatic mitral stenosis from 120 medical centers in China underwent PBMV by the Inoue technic. There were 1440 men and 3392 women with a mean age of 36.8 +/- 12.3 years. The procedure success rate was 99.30%. Major complications included death in 0.12%, > or = 3+/4+ mitral regurgitation in 1.41%, cardiac tamponade in 0.81%, and thromboembolism in 0.48%. After PBMV, the mean left atrial pressure decreased from 26.2 +/- 7.6 mm Hg to 11.4 +/- 6.1 mm Hg (p < 0.001); mean mitral diastolic gradient decreased from 18.3 +/- 5.1 mm Hg to 5.4 +/- 3.1 mm Hg (p < 0.001); pulmonary artery systolic pressure decreased from 51.2 +/- 14.8 mm Hg to 33.9 +/- 8.8 mm Hg (p < 0.001); cardiac output increased from 3.8 +/- 1.3 L/min to 4.8 +/- 1.2 L/min (p < 0.001); and mitral valve area expanded from 1.1 +/- 0.3 cm2 to 2.1 +/- 0.2 cm2 (p < 0.001). Functional status was NYHA class IV in 5.6%, class III in 38.8%, class II in 55.5%, and class I in 0.1% of patients before PBMV and improved to class I in 75.8%, class II in 23%, and class III in 1.2% after PBMV. The rate of restenosis was 5.2% over a follow-up period of 32.2 +/- 14.2 months in the entire group and 4.6% over a follow-up period of 5.1 +/- 1.0 years in Guangdong Cardiovascular Institute, where PBMV was begun in China.(ABSTRACT TRUNCATED AT 250 WORDS)