Clinical and biochemical parameters in chronic kidney disease with pulmonary hypertension

Risk Factors of Pulmonary Hypertension in Patients on Hemodialysis: A Single Center Study

Introduction

Pulmonary hypertension (PH) is an underestimated cardiovascular consequence and a mortality predictor in patients on hemodialysis (HD). Thus, we studied its prevalence, risk factors, association with inflammation/oxidative stress, and cardiac changes in HD patients.

Methods

This was a single-center cross-sectional observational study conducted at a tertiary care hospital. Patients aged >18 years on hemodialysis for at least three months were included and divided into those with and without PH; patients with secondary causes for PH were excluded. Clinical characteristics, HD-related factors, lab parameters (C-reactive protein and malondialdehyde with thiol assay were used as markers of inflammation and oxidative stress, respectively), and echocardiography details were compared. PH was defined as a mean pulmonary artery pressure of >25 mmHg at rest, and it was further divided as mild (25–40 mmHg), moderate (40–60 mmHg), and severe (>60 mmHg).

Results

Of 52 patients, 28 patients had PH (mild 24, moderate 4, and none had severe PH) with prevalence of 54%. No difference was found in clinical characteristics, dialysis-related factors, biochemical parameters including inflammation (C-reactive protein; p=0.76), or oxidative stress (thiol; p=0.36 and MDA; p=0.46) between the groups. When compared to individuals without PH, HD patients with PH exhibited significantly more mitral regurgitation (p=0.002).

Conclusion

Hemodialysis patients have a high prevalence of PH. PH was significantly associated with the presence of mitral regurgitation on echocardiography. Our study did not find differences in traditional risk factors, HD-related factors, and inflammation/oxidative markers between the groups with and without PH.

Case series of 5 patients with end-stage renal disease with reversible dyspnea, heart failure, and pulmonary hypertension related to arteriovenous dialysis access

Patients with end-stage renal disease (ESRD) with arteriovenous dialysis access (AVDA) can develop symptoms of heart failure and pulmonary hypertension (PH). We report on 5 patients with ESRD and AVDA who presented with shortness of breath, heart failure, and PH. All patients had partial or complete closure of AVDA and were reevaluated after AVDA revision. All 5 subjects had clinical and echocardiographic evidence of heart failure, hypertensive heart disease, left ventricular diastolic dysfunction, and PH at baseline. After complete closure ([Formula: see text]) or partial banding ([Formula: see text]) of AVDA, mean New York Heart Association class improved from [Formula: see text] to [Formula: see text] ([Formula: see text]). Mean 6-minute walk distance improved from [Formula: see text] to [Formula: see text] m ([Formula: see text]). Serial echocardiography revealed a decrease in the right ventricle∶left ventricle ratio from [Formula: see text] to [Formula: see text] ([Formula: see text]) and improved diastolic dysfunction parameters. On right heart catheterization before definitive AVDA revision, acute manual fistula or graft occlusion led to an average decrease in cardiac output of 1.1 L/min with no other changes in hemodynamics: [Formula: see text] to [Formula: see text] L/min ([Formula: see text]). However, the average decrease in cardiac output after definitive revision of the AVDA (mean, 90 days) was 4.0 L/min with marked improvements in biventricular filling pressures and pulmonary artery pressure. In patients with ESRD and AVDA presenting with heart failure and PH, revision or closure of AVDA can markedly improve dyspnea as well as the clinical, echocardiographic, and hemodynamic manifestations of heart failure and PH.

Effect of allopurinol on blood pressure and aortic compliance in hypertensive patients

BACKGROUND

Arterial hypertension is commonly associated with hyperuricemia. Several studies have shown that allopurinol reduces arterial blood pressure in animal models and in adolescent patients with newly diagnosed hypertension. Moreover, allopurinol has shown beneficial effects on endothelial function and arterial wave reflection in contrast to uricosuric agents. Antihypertensive drugs produce different effects on serum uric acid levels.

OBJECTIVE

The aim of the study was to evaluate the influence of allopurinol on blood pressure and aortic compliance in patients with arterial hypertension depending on hypotensive therapy with angiotensin-converting enzyme inhibitor (ACE-I) or thiazide diuretic, hypotensive drugs with distinct effects on serum uric acid levels and conversely, a positive influence on pulse wave velocity (PWV) in the aorta.

MATERIAL AND METHODS

Sixty-six patients aged 25-70 (mean age 46.17 ± 10.89) with mild and moderate arterial hypertension diagnosed on the basis of office blood pressure, were studied. They were randomized to antihypertensive therapy on either perindopril (n = 35) or hydrochlorothiazide (n = 31). After 8 weeks of antihypertensive therapy, 150 mg of allopurinol daily was added for the next 8 weeks. Measurement of the serum uric acid level, PWV and 24-h ambulatory blood pressure monitoring (ABPM) were performed at baseline, after 8 weeks antihypertensive therapy and again after the final 8 weeks with the additional allopurinol.

RESULTS

No significant changes in systolic (SBP) and diastolic blood pressure (DBP) or ABPM were observed after allopurinol treatment in either of the subgroups receiving ACE-I or thiazide-based antihypertensive therapy. The mean PWV decreased from 10.7 ± 1.4 m/s to 10.0 ± 1.2 m/s (p = 0.00008) in the ACE-I-based therapy subgroup and from 11.5 ± 1.7 m/s to 10.4 ± 1.5 m/s (p = 0.00002) in the thiazide-based therapy subgroup after treatment with allopurinol. However, significant correlations were found between PWV changes and the basic PWV (r = -0.52; p < 0.001) or SBP changes (r = 0.29; p < 0.019) after allopurinol treatment.

CONCLUSIONS

Allopurinol does not produce additional antihypertensive effects in patients with treated arterial hypertension. Allopurinol increases aortic compliance independently of ACE-I or thiazide-based, antihypertensive therapy. However, this effect is significantly dependent on the initial PWV in the aorta and on SBP changes during allopurinol therapy.