Conference: 2010 International PHA Conference and Scientific Sessions
Release Date: 06.24.2010
Presentation Type: Abstracts
Le R, Fenstad E, Maradit-Kremers H, McCully R, Frantz R, McGoon M, Kane G.
Mayo Clinic, Rochester, MN, USA
BACKGROUND: Adults with pulmonary arterial hypertension usually present with dyspnea. However, syncope by historical data may occur in up to 30% of patients with PAH. Despite the frequency with which syncope is thought to be present, its implications on the course of the disease have not yet been well characterized. The echocardiographic and hemodynamic features specific to patients with syncope remain ill defined.
METHODS: Single center cohort study of 475 adult patients with Group 1 PAH first seen between 1995 and 2006. All patients completed a standardized symptom assessment at the time of diagnosis. Initial clinical, echocardiographic and hemodynamic data as well as survival status were compiled as of July 1, 2009. Survival status was available in all patients with details of cause and setting of death in approximately 60%.
RESULTS: 53 (11.2%) patients presented with syncope at the time of PAH diagnosis. There were no significant differences in gender, age, functional class of dyspnea, six-minute walk or etiology of PAH in those who presented with syncope compared to those without. The echocardiographic characteristics of patients with PAH with syncope versus without syncope included more patients with severe right atrial (p=0.04) and right ventricular enlargement (p=0.04) and more patients with pericardial effusions (p=0.04). Right heart catheterization revealed higher right atrial pressures (p=0.04) and lower cardiac outputs in patients with syncope (p=0.01). One, 3 and 5 years survival was lower in syncopal (73%, 55%, 41%) versus non-syncopal (86%, 70%, 55%; p<0.01) patients. In syncopal patients, those who died at follow-up were older (p=0.001), had lower GFR (p=0.002), higher BNP (p=0.03) and lower DLCO (p=0.01); they were more likely to have collagen vascular disease (p=0.03) than other types of PAH. By echocardiography, syncope patients who died were more likely to have severe right ventricular enlargement (p=0.03) and severe tricuspid valve regurgitation (p=0.02) compared to patients with syncope who survived; they also had higher right atrial pressures (p=0.02). After factoring in age, sex, WHO/NYHA dyspnea class, etiology of PAH, 6 minute walk distance and findings on echocardiography and right heart catheterization; syncope was the most predictive variable of death [hazard ratio 2.56 (95% confidence interval 1.26, 4.84)]. Where available PAH played a primary or secondary role in mortality, with death invariably preceded by a progressive decline in functional status and right heart failure. There was no apparent difference between syncopal and non-syncopal patients. Unexpected sudden death was relatively low and no higher in the syncopal group.
CONCLUSIONS: In a broad spectrum of clinical PAH patients, syncope is infrequent, associated with markers of right heart dysfunction and remains independently predictive of poor outcome.