Pulmonary Hypertension in Patients with Chronic Renal Failure

Abstract

Background: Many etiologies causing pulmonary hypertension (PH) have been reported, and one of the background disease seen with patients with PH is chronic renal failure (CRF); however, the pathogenesis of PH in this group of patients is not explained satisfactorily. Objectives: The aims of this study were to evaluate the incidence of unexplained PH among patients with CRF and to suggest possible etiologic factors. Methods: Two hundred and eleven patients with CRF were evaluated and the ones who have comorbid conditions that cause PH were excluded. Pulmonary arterial pressure (PAP) and cardiac functions were evaluated by Doppler echocardiography. Arteriovenous fistula (AVF) flow was measured by Doppler sonography. The patients were followed for at least 6 months. Results: Forty-eight CRF patients (20 males, 28 females) were included: 23 were predialysis patients, and 25 patients received hemodialysis via AVF. Patients were followed for 7.5 ± 1.01 months. Systolic PAP >35 mm Hg was found in 56% (14/25) of patients receiving hemodialysis (36.8 ± 10.7 mm Hg) and in 39.1% (9/23) of predialysis patients (29.5 ± 9.5 mm Hg). The parathyroid hormone level, cardiac output values and CRF duration were found to be increased in patients with elevated systolic PAP (p < 0.05). AVF flow and AVF duration were positively correlated with systolic PAP in patients receiving hemodialysis (p < 0.05). There was a negative correlation between systolic PAP and residual urine volume (p < 0.05). AVF compression in hemodialysis patients decreased systolic PAP from 36.8 ± 10.7 to 32.8 ± 10.5 mm Hg. Systolic PAP values were increased at the end of the study in the predialysis group, whereas they were decreased at the end of the follow-up in the hemodialysis group (36.9 ± 10.5 and 32.04 ± 10.5 mm Hg, respectively). Conclusions: This study demonstrates a high incidence of PH among patients with CRF. CRF duration, AVF flow, parathyroid hormone level and cardiac output may be involved in the pathogenesis of PH. The effective hemodialysis and dry weight reduction decreased systolic PAP values.

Prevalence of Pulmonary Hypertension in Patients with Early Stages of Chronic Renal Disease

“…Additionally, the prevalence of PHT in the stage 1-4 CKD patients and stage 5 patients was similar. Studies on non-dialysis-dependent stage 5 CKD patients reported that the prevalence of PHT ranges from 9-39% and that the prevalence of PHT is higher in patients undergoing dialysis than in nondialysis patients (9)(10)(11)(12). In the present study the prevalence of PHT in patients with stage 5 CKD not undergoing HD was 58.3%, which is higher than reported earlier (9,11,13,14).…”

“…Accordingly, we think in addition to CKD patients undergoing HD early-stage CKD patients should also be considered high risk patients. In most studies on patients with CKD, sPAP has been estimated as Doppler-derived sPAP and various sPAP cut offs have been used, ranging from 25 to ≥45 mmHg (9,11,(13)(14)(15). In the present study sPAP ≥35 mmHg based on Doppler echocardiography was considered diagnostic for PHT and the high prevalence of PHT in this study may be explained due to the lack of uniformity in diagnostic criteria and sPAP cutoffs in the literature.…”

“…Patients with an AVF had a high incidence of PHT due to increased cardiac output and it has been reported that the incidence of PHT in stage 5 CKD patients with an AVF was 40-50% (12,22). Although Havlucu et al (11) showed that the presence of PHT in patients with an AVF was significantly higher than that in patients without an AVF, Yigla et al (9) reported that mean sPAP significantly decreased after successful renal transplantation in CKD patients, while their AVF was intact. It was reported that compression of AVF can decrease cardiac output and sPAP, and that an AVF increases sPAP via elevation of cardiac output (23).…”

“…Studies on non-dialysis-dependent stage 5 CKD patients reported that the prevalence of PHT ranges from 9-39% and that the prevalence of PHT is higher in patients undergoing dialysis than in nondialysis patients (9)(10)(11)(12). In the present study the prevalence of PHT in patients with stage 5 CKD not undergoing HD was 58.3%, which is higher than reported earlier (9,11,13,14). In addition, there weren't any significant differences in sPAP or the prevalence of PHT between the patients undergoing and not undergoing HD.…”

Presence and Outcomes of Kidney Disease in Patients with Pulmonary Hypertension

“…Our data, which include all classes of PH, reveal a higher proportion of CKD in those patients with PH (36% in this study versus 4% in REVEAL). Similarly, Havlucu et al (25) reported a PH prevalence rate of 39% (assessed using Doppler echocardiogram) among those patients with nondialysis-dependent CKD. Underlying muscle mass influences serum creatinine generation (and thus, eGFR), and patients with PH might have muscle wasting from chronic heart failure, thereby underestimating the kidney function.…”