Background and aim of the study: Mitral stenosis (MS) with severe pulmonary hypertension (PHT) constitutes a high-risk subset for surgical commissurotomy or valve replacement. Mitral balloon valvuloplasty (MBV) has emerged as the treatment of choice for patients with severe pliable MS. The efficacy of this procedure in patients with severe PHT has not been fully elucidated, notably with regards to the long-term outcome.
Methods: MBV was successfully performed in 531 consecutive patients. Of these patients, 82 (15%) had severe PHT at baseline (group A), defined as pulmonary artery systolic pressure (PASP) at rest > 60 mmHg, compared to the remaining 449 patients, who served as controls (group B).
Results: Patients with PHT had a higher echo score and were more symptomatic, the majority (52.4%) having moderate to severe tricuspid regurgitation (TR). When comparing PHT with controls, the left atrial pressure was higher (28 +/- 4.9 versus 25.6 +/- 4.6 mmHg; p < 0.0001), the mean mitral gradient was similar (14.6 +/- 3.8 versus 14.4 +/- 2.1 mmHg; p = 0.30), the baseline mitral valve area (MVA) was smaller (0.72 +/- 0.17 versus 0.86 +/- 0.19 cm2; p < 0.0001), pulmonary vascular resistance was higher (612 +/- 343 versus 211 +/- 183 dyne/s/cm(-5); p < 0.0001), and post-procedure MVA was smaller (1.7 +/- 0.44 versus 1.85 +/- 0.54 cm2; p = 0.007). The PASP decreased significantly over 12 months after MBV, from 79 +/- 14 to 36.7 +/- 7.53 mmHg (p < 0.0001). Freedom from restenosis in PHT patients at 10 and 15 years, respectively, was 66 +/- 6% and 45 +/- 8% versus 78 +/- 2% and 47 +/- 3% in controls (p = 0.0066). Event-free survival at 10 and 15 years, respectively, was 77 +/- 6% and 41 +/- 11% in PHT patients versus 89 +/- 1% and 54 +/- 4% for controls (p = 0.0169). In total, 33 patients (40%) had moderate TR and 10 (12%) had severe TR at baseline. At follow up, only 12 patients had moderate TR and none had severe TR.
Conclusion: MBV is a safe and effective technique for treating patients with MS and severe PHT. Although the immediate results were comparable with those in controls, the long-term results proved to be slightly inferior, with a regression of PHT and concomitant severe TR.