Pulmonary Hypertension and Elevated Transpulmonary Gradient in Patients with Mitral Stenosis

Background And Aim Of The Study: Pulmonary hypertension frequently complicates mitral stenosis, with a subset of these patients exhibiting pressures well in excess of their mitral valve hemodynamics. The prevalence of this condition and its impact on clinical outcome following percutaneous balloon mitral commissurotomy (PBMC) is unknown.

Methods: The transpulmonary gradient (TPG) was measured in 317 patients undergoing PBMC; patients were subsequently defined as having either an appropriate or excessive TPG (< or =15 mmHg or >15 mmHg, respectively). Twenty-two patients were excluded due to valvuloplasty-related significant mitral regurgitation. The remaining 295 patients (250 females, 45 males; mean age 52 +/- 13 years) were prospectively followed up, with each patient underwent serial echocardiography.

Results: Among the patients, 214 (73%) had pulmonary hypertension (pulmonary artery pressure >25 mmHg) and 55 (19%) also had an elevated TPG. Females were almost fivefold more likely than males to have an elevated TPG (p = 0.003). Patients with an elevated TPG had a worse mean NYHA functional class than those with a normal TPG (3.0 +/- 0.5 versus 2.7 +/- 0.6, p = 0.01), while the mitral valve area (MVA) was slightly smaller in patients with an elevated TPG (1.0 +/- 0.2 versus 1.1 +/- 0.2 cm2, p = 0.003). All patients demonstrated a significant increase in MVA after commissurotomy (final MVA 1.7 +/- 0.6 cm2, p < 0.001 for elevated TPG; 1.8 +/- 0.4 cm2, p < 0.001 for normal TPG), and the NYHA class at six months was improved for all patients (2.8 +/- 0.6 versus 1.6 +/- 0.7, p < 0.001). The improvements in NYHA class, TPG and MVA were sustained at 36 months.

Conclusion: Pulmonary hypertension with elevated TPG occurs in patients with mitral stenosis, and is significantly more common in females. Despite worse symptoms and higher right-sided pressures, PBMC is equally successful in patients with a normal TPG, and provides sustained benefit for up to 36 months after the procedure.