Reversible airway obstruction in rheumatic mitral valve disease

Area of Science:

• Cardiology
• Pulmonology
• Respiratory Medicine

Background:

• Advanced mitral stenosis can lead to obstructive ventilatory patterns.
• A significant percentage of patients exhibit reduced forced expiratory volume in 1 second (FEV1) preoperatively.
• Obstructive patterns can persist postoperatively in some patients following mitral valve replacement (MVR).

Purpose of the Study:

• To investigate the reversibility of airflow obstruction in patients with mitral stenosis.
• To evaluate the effect of salbutamol (a beta2 agonist) on lung function pre- and post-MVR.
• To assess changes in airway resistance (Rex) and intrathoracic gas volume (VTG).

Main Methods:

• A blind study involving 24 patients scheduled for MVR.
• Preoperative and 6-month postoperative lung function tests, including flow volume curves and body plethysmography.
• Administration of placebo and salbutamol inhalations to assess response.

Main Results:

• Significant improvements were observed with salbutamol compared to placebo for FEV1, FEV1% FVC, PEFR, Vmax50, Rex, and VTG (P<0.001).
• These improvements were noted in both the preoperative and postoperative periods.
• Forty percent of patients had preoperative FEV1 < 60% predicted, with 25% showing similar patterns postoperatively.

Conclusions:

• Salbutamol inhalation effectively improves obstructive lung impairment in patients with mitral stenosis.
• The benefits of salbutamol are evident both before and after mitral valve replacement.
• Airway obstruction is a relevant issue in MVR patients, with potential for pharmacological improvement.