EHRCT is superior to the pulmonary function test at showing small airway disease in patients with isolated mitral valve stenosis

Introduction: We investigated whether expiratory high resolution computed tomography (EHRCT) is superior to the pulmonary function test (PFT) in showing small airway disease (SAD) in patients with isolated mitral valve stenosis (MVS). Methods: Sixty patients contributed to the study prospectively. Cases were divided into three groups (mild, moderate, severe) on the basis of MVS and PAP. Results: A highly significant relation was determined between severity of MVS and both FEV1 (p<0.002) and FVC (p<0.007). Mean FEV1 in patients with severe MVS were significantly lower than those of cases of mild and moderate MVS (p=0.015, p=0.004). Highly significant variation was also determined between FEF25-75% based on severity of MVS (p<0.003). Mean FEF25-75% of cases of severe MVS were significantly lower than those of the mild and moderate cases (p=0.008, p=0.009). Significant variation was determined between mean FEV1 depending on PAP classifications (p<0.038). Significant variation was also observed among mean FEF25-75% in terms of PAP (p<0.005). FEF25-75% of cases with air trapping in cases of moderate and severe MVS were significantly lower than those of cases without air trapping (p=0.043, p=0.016). Mean FEF25-75% of all cases with air trapping were highly significantly lower than those of cases without air trapping (p<0.001). A significant difference was determined when presence of air trapping was assessed according to EHRCT and FEF25-75% in cases with mild and moderate MVS (p=0.021, p=0.016). Conclusions: According to our knowledge, this is the first study to show the superiority of EHRCT over PFT (FEF25-75%) in showing SAD in patients with isolated MVS (mild and moderate stages but not in severe MVS) without additional respiratory disease.