Pulmonary Hypertension in CKD

Abstract

Pulmonary hypertension (PH), defined as a mean pulmonary artery pressure (mPAP) $25 mmHg, is described in numerous pathologic conditions and its presence is typically associated with worse outcomes. Experts in the field have established a clinical classification system which places patients with PH into five groups according to shared pathobiology, clinical presentation, and therapeutic approaches. 1 Although patients with CKD exhibit many symptoms and risk factors associated with PH, literature describing the epidemiology and impact of PH in CKD has been limited. Until recently, in fact, this literature was limited to CKD stages 4 and 5 with and without dialysis dependency. In these patients with advanced CKD, PH is prevalent (approximately 30%-40%) and associated with worse outcomes. 2,3 Reflective of poor insight into the nature of PH in this population, individuals with PH and ESRD are included in group 5 PH -that due to cryptic or multifactorial etiologies. The larger population with earlier stages of CKD bears a very high burden of cardiovascular morbidity and mortality; therefore, gaining additional knowledge related to PH in this population is of clinical relevance.The current study from Navaneethan et al. leverages the power of the Chronic Renal Insufficiency Cohort (CRIC), a large (n52959) longitudinal cohort study of subjects with eGFR 20-70 ml/min per 1.73 m 2 , providing the most comprehensive description to date of PH prevalence and significance in a nondialysis CKD population. 4 CRIC subjects underwent transthoracic Doppler echocardiography (TTE) interpreted centrally in a core laboratory, as well as detailed ascertainment of covariates and comorbid conditions, and thorough adjudication of cardiovascular and kidney outcomes. The authors used an accepted echocardiographic case definition of PH: pulmonary artery systolic pressure (ePASP) .35 mmHg and/or tricuspid regurgitant velocity .2.5 m/s.Concordant with recent studies from Italy and China, 5,6 PH was prevalent in the CRIC, present in roughly one in five subjects (21%), and was significantly and indirectly related to the eGFR, rising from 6% among CKD stage 1 to 33% in CKD stage 5. As has been described in other studies, PH was associated with older age, systemic hypertension, diabetes, and a history of heart failure (HF). 5,7 Multivariable analysis found that older age, lower hemoglobin, lower left ventricular ejection fraction, and the presence of left ventricular hypertrophy were independently associated with PH. The presence of PH was associated with a 38% increased risk of overall mortality and a 23% increased risk of cardiovascular events (HF, myocardial infarction, cerebrovascular accident, and peripheral vascular disease). In this cohort PH was not associated with progression of CKD.This study has value, not only for the relative novelty of the message that PH is prevalent in all stages of CKD, but additionally for its ability to assess predictors and mortality related to PH using a more systematized approach than prior studies. Despite ...

The value of ventricular gradient for predicting pulmonary hypertension and mortality in hemodialysis patients

“…In the present study VG-RVPO values were higher in HD patients compared to controls, and 55.5% of patients were classified into intermediate and high risk groups for PHT based on echocardiographic parameters. This suggests that PHT is prevalent in HD patients, a finding in agreement with previous studies demonstrating that the prevalence of PHT is around 18.8–68.8%, depending on the criteria adopted for PHT diagnosis, selection factors and co-morbidities 2 , 5 , 8 , 10 , 36 , 37 . Right heart catheterization was not included in the study protocol because of medical-ethical reasons.…”

The impact of vascular access location on pulmonary arterial pressure in chronic kidney disease patients undergoing hemodialysis

“…About two‐thirds of this study sample had anemia. Anemia is known to contribute to PH by inducing a state of hyperdynamic circulation in the pulmonary vasculature 30 . Systolic arterial blood pressure is an established predictor of pulmonary hypertension, 24,25 and systolic arterial blood pressure was found to be an independent predictor of PASP in this study after controlling for other covariates.…”

“…AVF-mediated PH is characterized by increased cardiac output and normal or increased pulmonary artery wedge pressure. 30 Though PASP estimated by echocardiogram is a reliable proxy for measured pulmonary artery pressure, to resolve whether PH in a given patient is attributable to AVF, mechanistic insight into the pathogenesis of PH is required, and such information could be obtained only with right heart catheterization.…”

Prognosis of Heart Valve Calcification on Cardiovascular Events in Hemodialysis Patients without Central Venous Catheters

“…The incidence of PH in patients with MHD is approximately 25–49%. PH leads to an increased risk of all-cause mortality [26, 27]. In this paper, PASP >30 mm Hg was found in 48.10% of HD patients; however, there was no statistically significant difference between the two groups, and most of the PASP values were mildly elevated, as there were 18 (11.39%) patients with PASP >45 mm Hg and only 2 (1.27%) with PASP >60 mm Hg.…”