ORLANDO — Echocardiography overestimates the true prevalence of primary pulmonary hypertension in hemodialysis patients with end-stage renal disease, according to a study presented at a meeting sponsored by the National Kidney Foundation.
For this reason, hemodialysis patients with echocardiographic evidence of pulmonary artery hypertension (PAH) should undergo right heart catheterization for confirmation, Dr. Ifeanyi Isaiah and colleagues, of Temple University, Philadelphia, wrote in a poster.
The reported prevalence of PAH in hemodialysis patients ranges from 27% to 40%, but these numbers are based on studies that relied exclusively on echocardiographic estimates of pulmonary arterial pressures to make the diagnosis.
The more accurate way of making the diagnosis is with right heart catheterization, Dr. Isaiah and colleagues wrote.
To establish the true prevalence of PAH in this population, the investigators conducted a retrospective, observational analysis of all echocardiographic and right heart catheterization studies done in their outpatient hemodialysis unit from January 2000 to December 2006.
Of the 502 patients included in the analysis, the majority (439 patients, or 87.5%) had undergone echocardiography. Pulmonary arterial pressure greater than 40 mm Hg, suggesting the presence ofPAH, was documented in 127 of the echocardiography patients (28.9%).
Data for right heart catheterization, which were available for 22 of these 127 patients, showed that 11 (50%) of them had elevated pulmonary arterial pressure.
Although the results showed that pulmonary hypertension may be overestimated, the study also “confirms a higher prevalence of pulmonary hypertension in end-stage renal disease patients receiving hemodialysis than [in] the general population,” the investigators wrote.
In addition to providing a more accurate diagnosis of PAH in hemodialysis patients, right heart catheterization is valuable in distinguishing those patients whose elevated pulmonary pressure results from heart failure from those who have isolated PAH with no heart failure, they added.