Percutaneous balloon mitral valvuloplasty in patients with severe mitral stenosis and low transmitral diastolic pressure gradient.

An elevated left atrial pressure and high diastolic pressure gradient (DPG) across the mitral valve are the major hemodynamic abnormalities in mitral stenosis (MS). However, a subgroup of patients with severe MS is characterized by low initial DPG. The authors reviewed the clinical, echocardiographic and hemodynamic data as well as procedural results in 180 patients who underwent percutaneous balloon mitral valvuloplasty (PBMV). An initial mean DPG > 10 mmHg was found in 144 patients (80%) (group A) and mean DPG < or = 10 mmHg in 36 patients (20%) (group B). Patients in group A had higher left ventricular ejection fraction (LVEF) than in group B (61 +/- 5% versus 42 +/- 6%, respectively) and higher cardiac index (2.8 +/- 0.4 versus 2.0 +/- 0.3 l/min/m(2) ). In group B 12 patients (33%) had normal LVEF, whereas 24/36 (67%) had reduced LVEF. All the latter had wall motion abnormalities on ventriculography. Unlike group A, intraprocedural echocardiography was essential for monitoring and evaluating immediate results of PBMV in group B. On follow-up of three years, 75% of group A patients and 55% in group B were in functional class I (p < 0.05). PBMV did not significantly improve symptoms in patients in group B who had preprocedure LVEF < or = 35%.