Background and aims of the study: Significant pulmonary hypertension in aortic stenosis is evidence of severe dysfunction of the left ventricle. It is also a predictor of a bad prognosis in the natural course of the disease. This study was performed to evaluate the changes in the hemodynamic parameters of pulmonary circulation at rest and effort in patients who had significant pulmonary hypertension preoperatively and underwent valve replacement.
Materials and methods: The study consists of 11 male patients with aortic stenosis with an average peak transvalvular gradient of 68 mmHg and impaired left ventricular function (mean ejection fraction 38%). Six patients were in NYHA functional class III, and five were in class IV. The patients underwent Swan-Ganz catheterization before urgent valve replacement.
Results: Significant pulmonary hypertension was found in all subjects, and a below normal cardiac index in eight. Urgent valve replacement was performed in all patients: two of them were operated on during pulmonary edema and cardiogenic shock which developed soon after diagnosis-one of them died. Patients were followed up six months after surgery, and all of them showed major clinical improvement (six in NYHA class I, four in class II). Mean pulmonary artery systolic pressure dropped from 77 mmHg preoperatively to 32 mmHg, and the pulmonary artery mean pressure from 47 mmHg to 17 mmHg, pulmonary wedge pressure from 32 mmHg to 9 mmHg, and pulmonary vascular resistance from 4.74 to 1.8 Wood units. The cardiac index came back to normal in all patients (2.18 vs. 3.0 l/min/m2). Swan-Ganz catheterization was also performed during exercise (work load; 50 Watts in three patients, 100 Watts in six patients). The reaction of the hemodynamic parameters on exercise in most patients was almost normal.
Conclusion: Our data indicate that in aortic stenosis, even with severe left heart failure, pulmonary hypertension can be fully reversible and a significant improvement in both rest and effort hemodynamic parameters can be expected.