Effect of Inoue balloon mitral valvotomy on severe pulmonary arterial hypertension in 315 patients with rheumatic mitral stenosis: immediate and long-term results.

BACKGROUND AND AIMS OF THE STUDY: Despite advances in surgical techniques, mitral valve surgery in patients with severe pulmonary arterial hypertension (PAH) causes considerable mortality and morbidity. Balloon mitral valvotomy (BMV) is an established alternative to treat high-risk surgical patients with mitral stenosis (MS). The study aims were to evaluate immediate and long-term efficacy of BMV in patients with MS and severe PAH, compared to those with mild/moderate PAH.

METHODS: Among 1,125 patients who underwent Inoue BMV, 315 had severe PAH (mean pulmonary artery (PA) pressure > or = 50 mmHg (group I; 79 of these patients had suprasystemic PAH). Results from this group were compared with those of patients with mild/moderate PAH (group II).

RESULTS: Group I patients were younger and more symptomatic (mean PA pressure 62 +/- 10.6 mmHg versus 32.6 +/- 8.2 mmHg in group II). Before BMV, mean transmitral gradient (17.8 +/- 6.5 versus 14.4 +/- 5.4 mmHg) and pulmonary capillary wedge pressure (PCWP) (31.6 +/- 6.1 versus 22.8 +/- 6.2 mmHg) were significantly higher, while mitral valve area (MVA) (0.66 +/- 0.2 versus 0.85 +/- 0.2 cm2) was significantly lower in group I. After BMV, PA mean pressure was significantly reduced (34.8 +/- 11.2 and 21.1 +/- 8.4 mmHg), transmitral gradient (8.0 +/- 3.9 and 6.9 +/- 3.2 mmHg) and mean PCWP (12.8 +/- 5.8 and 11.0 +/- 5.1 mmHg) in groups I and II, respectively, with a comparable increase in MVA (1.77 +/- 0.4 and 1.84 +/- 0.5 cm2). Group I patients had worse baseline hemodynamic parameters than group II, but the former had a higher absolute gain in hemodynamic parameters. Residual severe PAH after BMV was seen in 9.8% of patients, with PA pressures normalized in 9.5%. Among 79 patients with suprasystemic PA pressure (mean PA systolic pressure 116.6 +/- 28.2 mmHg), 16.5% normalized their PA pressures and 25.3% had residual severe PAH. At mean follow up of 33 months, 80.4% were in NYHA class I. Mean PA systolic pressure in 161 patients was 39.0 +/- 14.2 mmHg compared with a post-BMV value of 55.0 +/- 16.9 mmHg; thus, a sustained fall in pressure was demonstrated at follow up.

CONCLUSION: Inoue BMV is safe and effective in patients with MS and severe PAH. Although these patients have worse clinical and hemodynamic parameters before BMV, they achieve a greater absolute gain in terms of improvement in all hemodynamic parameters.