Noninvasive diagnosis of pulmonary arterial hypertension in chronic obstructive pulmonary disease: right ventricular ejection fraction at rest.

Because right ventricular ejection fraction (RVEF) depends on impedance to RV ejection, the hypothesis was tested that an abnormality in radionuclide-determined RVEF would be a useful noninvasive predictor of pulmonary artery (PA) hypertension in patients with chronic obstructive pulmonary disease (COPD). Simultaneous measurements of resting RVEF and PA pressure were made in 30 patients with COPD. All were stable and without clinical evidence of respiratory decompensation or congestive heart failure. Eleven patients had normal (less than 20 mm Hg) mean PA pressure and 19 patients had PA hypertension. The average RVEF was 41 +/- 7% (range 29 to 60%). Five patients had normal (greater than 45%) and 25 patients depressed RVEF. An inverse linear relation between mean PA pressure and RVEF was present (r = -0.74). In the group with normal PA pressure, RVEF averaged 48% (range 42 to 60%). In the group with PA hypertension, RVEF averaged 36% (range 29 to 44%). RVEF was significantly higher in the group with PA hypertension. Using RVEF less than 45% as an indicator of PA hypertension, the sensitivity was 100%, the specificity 55%, and the predictive accuracy of a positive result 79%. Using RVEF less than or equal to 40% as an indicator of PA hypertension, the sensitivity was 75%, the specificity 100%, and the predictive accuracy of a positive study 100%. Thus, radionuclide-determined RVEF using the first-pass technique and a multicrystal camera is a useful noninvasive test for diagnosing PA hypertension in patients with advanced COPD.