ABSTRACT
BACKGROUND: Exercise-induced pulmonary hypertension (PH) is often seen in chronic thromboembolic PH (CTEPH) patients with normalized resting hemodynamics, but it is difficult to differentiate precapillary PH as pulmonary vascular dysfunction and post-capillary PH from occult-left ventricular dysfunction (LVD). The aim of this study was to examine whether the exercise-induced elevation of pulmonary arterial wedge pressure (PAWP) can be predicted by the echocardiographic index at rest.MethodsâandâResults:A total of 71 CTEPH patients (67±11 years old, male/female=15/56) treated by pulmonary angioplasty with near-normal pulmonary arterial pressure (PAP) and normal PAWP at rest underwent symptom-limited exercise test using supine cycle ergometer with right heart catheterization. Exercise-induced elevation in PAWP of >20 mmHg during exercise was defined as occult-LVD. Resting echocardiography was performed within 3 months. In the occult-LVD (n=28), PAWP at rest after leg raising for exercise (14±4 vs. 11±3 mmHg, P<0.001), and mean PAP during exercise were higher compared with the non-LVD (n=43). Peak oxygen consumption, cardiac output, and pulmonary vascular resistance at peak exercise did not differ between groups. Left atrial volume index (LAVi) in the occult-LVD was significantly larger (39.7±8.1 vs. 34.4±9.6 mL/m2, P=0.017). LAVi correlated with exercise PAWP (r=0.356, P=0.002), but not resting PAWP (r=0.161, P=0.179). CONCLUSIONS: Larger left atrial volume may reflect the exercise-induced PAWP elevation as occult-LVD in CTEPH patients.
Subject(s)
Echocardiography , Exercise , Hemodynamics , Hypertension, Pulmonary/diagnostic imaging , Pulmonary Artery/physiopathology , Pulmonary Embolism/complications , Aged , Angioplasty, Balloon , Arterial Pressure , Atrial Function, Left , Atrial Remodeling , Catheterization, Swan-Ganz , Chronic Disease , Diagnosis, Differential , Exercise Test , Female , Humans , Hypertension, Pulmonary/etiology , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/therapy , Male , Middle Aged , Predictive Value of Tests , Pulmonary Embolism/diagnosis , Pulmonary Embolism/physiopathology , Pulmonary Embolism/therapy , Pulmonary Wedge Pressure , Risk Factors , Vascular Resistance , Ventricular Function, LeftABSTRACT
BACKGROUND: Sleep apnea (SA) can cause repeated nocturnal arterial oxygen desaturation and result in acute increase in pulmonary arterial pressure (PAP). The presence of SA is associated with a poor prognosis in patients with chronic left-sided heart failure, but little is known for patients with pulmonary arterial hypertension (PAH). MethodsâandâResults: We enrolled 151 patients with PAH (44±16 years old, male/female=37/114). They were all in the Nice Classification group 1 (idiopathic PAH/associated PAH=52/48%, mean PAP of 46±16 mmHg). They underwent right-heart catheterization and a sleep study with simplified polysomnography. Averaged percutaneous oxygen saturation (SpO2) during sleep was measured and an apnea-hypopnea index >5 was defined as SA. SA was noted in 58 patients (obstructive SA/central SA: 29/29). Over an average follow-up of 1,170±763 days, 32 patients died. By Kaplan-Meier analysis, there was no significant difference in deaths of patients with and without SA (χ2=2.82, P=0.093). On the other hand, the mortality in patients with lower averaged SpO2 was significantly higher than in those with higher averaged SpO2 (χ2=14.7, P<0.001) and that was the only independent variable related to death in multivariate Cox proportional hazards analysis. CONCLUSIONS: SA in patients with PAH was not associated with worse prognosis, unlike left ventricular heart failure, but nocturnal hypoxemia was related to poor prognosis.
