Background: Heart failure with preserved ejection fraction can lead to pulmonary hypertension. The aim of the current study was to evaluate the diagnostic role of exercise during right heart catheterization in the unmasking of diastolic dysfunction.
Methods: Between 2004 and 2012 200 symptomatic patients with exertional dyspnea, normal lung function tests, preserved systolic function and suspected pulmonary hypertension were referred for right heart catheterization. Study population included 63 patients with rest post capillary wedge pressure (PCWP) ≤ 15 mmHg. Patients were divided to three tertiles based on their PCWP at exercise.
Results: Mean age was 60 ± 20 years, and 29% of the patients were men. Mean change in PCWP between rest and exercise was 0.0±4.3, 4.6±2.4, and 16.6±7.1 mmHg in the lower, middle and upper tertiles, respectively (Figure). Higher exercise PCWP tertiles were associated with reduced pulmonary vascular resistance at rest (8.3± 6.7, 2.9±2.7 and 5.8±4.6 Wood units; p=0.004) and during exercise (8.0±6.9, 2.9±2.1 and 3.2±2.4 Wood units; p=0.008). A multivariate linear regression model demonstrated that each 5 kg/m2 increase in body mass index was associated with 2.5±1.0 mmHg increase in exercise PCWP (p=0.017). In addition, multivariate binary logistic regression model showed that patients with borderline PCWP at rest were 5 times more likely to be in the upper tertile of exercise PCWP (HR=4.9, 95% CI [1.5-16.0] p=0.008).
Conclusions: In symptomatic patients with suspected pulmonary hypertension and preserved ejection fraction, exercise during right heart catheterization can unmask diastolic dysfunction. This is especially true for obese patients and patients with borderline resting PCWP.
