Can pulmonary venous hyper-tension be graded by the chest radiograph?

Aim: The chest radiograph is widely used for the diagnosis and follow-up of patients with pulmonary venous hypertension (PVH) caused by rheumatic hear t disease. Observer accuracy and interobserver agreement on the radiographi c diagnosis of PVH is rarely assessed. We have studied this accuracy and ag reement in 120 consecutive patients. Methods and Results: Patients were selected on the basis of mean pulmonary capillary wedge pressures (PCWP) obtained in the basal state, A chest radio graph was obtained within the 24 h before catheterization and was assessed by two observers blinded to the diagnosis and PCWP, PVH was graded as absen t (PCWP < 12 mmHg); mild (PCWP 12-19 mmHg; redistribution of blood flow and hilar haze); moderate (PCWP 20-25 mmHg; septal oedema, pleural effusion) a nd severe (PCWP > 25 mmHg; alveolar oedema), Observer and interobserver agr eement was quantified by using the Kappa (kappa) statistic. The radiological assessment coincided with the measured PCWP in 52% of the patients according to observer 1 and 43% of the patients according to obser ver 2 (kappa 0.36 and 0.24), indicating poor agreement with haemodynamic va lues. Interobserver agreement was poor (kappa 0.3-0.35). Observer accuracy and interobserver agreement increased when the radiographic criteria were u sed to distinguish patients with normal PCWP from those with abnormal press ures when 85% and 78% of radiographs were correctly classified (kappa 0.6 a nd 0.5) by observers 1 and 2, respectively. Overall agreement was significa nt (kappa 0.6). In differentiating patients with a PCWP > 20 mmHg from thos e with a PCWP < 20 mmHg, 78% and 75% of radiographs were correctly classifi ed, giving kappa values of 0.6 and 0.5, Overall observer agreement was sign ificant (kappa 0.6). Conclusion: The chest radiograph is useful in detecting the presence of PVH and in distinguishing significant elevations in PCWP (>20 mmHg) from mildl y elevated PCWP. There is poor correlation between haemodynamic and radiogr aphic findings when more precise grading of the severity of PVH is attempte d.