Objectives: We aimed to identify the bronchial response
to inhaled methacholine in patients with mitral stenosis (MS) and to
clarify whether or not the bronchial hyperreactivity (BHR) is
reversible after percutaneous mitral balloon valvulotomy (PBMV).
Patients and setting: Thirty patients with MS and 28
age-matched healthy control subjects were prospectively evaluated with
pulmonary function tests and methacholine challenge. The productive
concentration of methacholine causing 20% decrease in FEV1
(PC20) was calculated and used as a parameter of bronchial
responsiveness. BHR was defined as a PC20 < 8 mg/mL. Mean
pulmonary artery pressure (PAP) and mean pulmonary capillary wedge
pressure (PCWP) were recorded in all patients through a Swan-Ganz
balloon-tipped catheter. Sixteen patients underwent PMBV, and a
methacholine test was repeated after each procedure.
Results: Bronchial response to methacholine was
significantly increased in patients with MS, so that 53% of them had
BHR, whereas all control subjects were nonresponders. The
PC20 was closely correlated with the PAP (r = − 0.777;
p < 0.001), PCWP (r = − 0.723; p < 0.001), and mitral valve
area (MVA; r = 0.676; p < 0.001). Balloon valvulotomy was
successfully performed in all of the 16 patients, and the cardiac
parameters (MVA, PAP, and PCWP) significantly improved after the
procedure. In contrast, no significant changes were shown in pulmonary
function test variables (total lung capacity, vital capacity [VC],
FEV1, and FEV1/VC). Although significant
improvement was observed in the mean PC20 values (from
4.97 ± 5.24 to 7.47 ± 6.96 mg/mL; p = 0.0006), BHR was
completely eliminated in only one patient.
Conclusions: Our data shows that BHR is fairly common among
patients with MS, and severity of bronchial responsiveness is
significantly correlated with the severity of MS. Moreover, PMBV leads
to significant reduction in pulmonary congestion and a consequent
improvement in BHR.