Determinants of cardiorenal damage progression in normotensive and never-treated hypertensive subjects

Noninvasive central pulse pressure is an independent determinant of renal function

The purpose of this study was to investigate the prognostic properties of different BP measurements for renal function decrement and early chronic kidney disease (CKD) in community-dwelling populations with normal renal function at baseline. A total of 1426 participants were included and followed for a median of 4.8 years (interquartile range, 4.5-5.2), and central hemodynamic profile and estimated glomerular filtration rate (eGFR) were evaluated. One main outcome was the rapid eGFR decline defined as a decline in eGFR of greater than 3 mL/min per 1.73 m² per year; the other was the new incidence of CKD. At the end of follow-up, mean eGFR decreased from 93.39 ± 13.46 mL/min per 1.73 m² to 85.72 ± 14.81 mL/min per 1.73 m² , and the incidence of rapid eGFR decline and CKD were 20.7% and 5.6%, respectively. In multivariate linear regression analysis, central pulse pressure (PP), age, fasting blood glucose, and concentration of homocysteine were independent determinants of the change in renal function. Not only in the prediction of rapid eGFR decline but also in the incident of CKD, baseline central PP was the only BP component that consistently independently associated with both outcomes after adjustment for various confounders. When compared with subjects in the lowest quartile of central PP, those in the highest quartile demonstrated a significantly increased risk of CKD (hazard ratio [HR], 1.57; 95% confidence interval [CI], 1.08-2.96; P = .006). The study showed that central PP emerged as an independent predictor of the decline in renal function.

Prognostic Value of the Estimated Glomerular Filtration Rate Decline in Hypertensive Patients Without Chronic Kidney Disease

BACKGROUND

Our objective of this study was to determine if rate of estimated glomerular filtration rate (eGFR) decline and its intensity was associated with cardiovascular risk and death in patients with hypertension whose baseline eGFR was higher than 60 ml/minute/1.73 m2.

METHODS

This study comprised 2,516 patients with hypertension who had had at least 2 serum creatinine measurements over a 4-year period. An eGFR reduction of ≥10% per year has been deemed as high eGFR and a reduction in eGFR of less than 10% per year as a low decline. The end points were coronary artery disease, stroke, transitory ischemic accident, peripheral arterial disease, heart failure, atrial fibrillation, and death from any cause. Cox regression analyses adjusted for potentially confounding factors were conducted.

RESULTS

A total of 2,354 patients with low rate of eGFR decline and 149 with high rate of eGFR decline were analyzed. The adjusted model shows that a -10% rate of eGFR decline per year is associated with a higher risk of the primary end point (HR 1.9; 95% CI 1.1-3.5; P = 0.02) and arteriosclerotic vascular disease (HR 2.2; 95% CI 1.2-4.2; P < 0.001) in all hypertensive groups. The variables associated to high/low rate of eGFR decline in the logistic regression model were serum creatinine (OR 3.35; P < 0.001), gender, women (OR 15.3; P < 0.001), tobacco user (OR 1.9; P < 0.002), and pulse pressure (OR 0.99; P < 0.05).

CONCLUSIONS

A rate of eGFR decline equal to or higher than -10% per year is a marker of cardiovascular risk for patients with arterial hypertension without chronic kidney disease at baseline. It may be useful to consider intensifying the global risk approach for these patients.

Retinal vascular caliber associated with cardiac and renal target organ damage in never-treated hypertensive patients

OBJECTIVE

The aim of this study was to assess the relationship between retinal vascular caliber and target organ damage in HT patients.

METHODS

Data were collected on cardiac, renal, vascular, and retinal variables in 88 consecutive never-treated HT subjects. Retinal vascular calibers were measured from fundus photographs by using a semi-automated computer-assisted program and summarized as CRAE and CRVE.

RESULTS

Mean CRAE and CRVE were significantly lower in patients with left ventricular hypertrophy (left ventricular mass ≥110 g/m² for women, 125 g/m² for men) than in those with normal left ventricular (CRAE: 129.4±3.7 vs 138.2±2.3 μm; P=.04; CRVE: 195.6±4.4 vs 209.8±2.7 μm; P=.008). CRAE and CRVE were negatively correlated with urinary albumin excretion (β±SE=-15.4±3.2, P<.0001 and β±SE=-11.9±4.4, P=.001, respectively) but were not correlated with estimated glomerular filtration rate (P=.21 and P=.75, respectively), carotid-to-femoral pulse wave velocity (P=.24 and P=.14), or carotid augmentation index (P=.43 and P=.16).

CONCLUSION

In never-treated HT patients, reduced CRAE and CRVE were associated with cardiac and renal preclinical damage, ie, left ventricular hypertrophy and albuminuria, but not estimated glomerular filtration rate or vascular stiffness.

Biphasic decline in renal function after radical cystectomy with urinary diversion

BACKGROUND

We evaluated short- and long-term renal function in patients after radical cystectomy with urinary diversion and identified risk factors for the deterioration of renal function.

METHODS

This retrospective study comprised 91 patients who underwent radical cystectomy and urinary diversion for bladder cancer and survived ≥3 years after surgery. The estimated glomerular filtration rate (eGFR) was calculated, and longitudinal changes of eGFR were assessed. Deterioration in renal function in early and late postoperative years was defined as a ≥25 % decrease in the eGFR from preoperative to postoperative year one, and a reduction in the eGFR of >1 mL/min/1.73 m² annually in subsequent years, respectively. Univariate and multivariate logistic regression analyses were used to evaluate its association with clinicopathologic features.

RESULTS

The median follow-up period after surgery was 7 years (range 3-26). The mean eGFR decreased from preoperative 65.1 to 58.9 mL/min/1.73 m² 1 year after the surgery, followed by a continuous decline of ~1.0 mL/min/1.73 m² per year thereafter. Multivariate analyses identified ureteroenteric stricture as the sole risk factor associated with early renal function deterioration [odds ratio (OR) 4.22, p = 0.037]. Diabetes mellitus (OR 8.24, p = 0.015) and episodes of pyelonephritis (OR 4.89, p = 0.038) were independently associated with the gradual decline in the late postoperative period.

CONCLUSION

In cystectomy patients with urinary diversion, the rapid deterioration of renal function observed during the first year after surgery and the gradual but continuous decline in function thereafter were found to be associated with different risk factors.

Trends in renal function after radical cystectomy and ileal conduit diversion: new insights regarding estimated glomerular filtration rate variations

INTRODUCTION

Our objectives were to evaluate the long-term renal function after radical cystectomy (RC) and ileal conduit diversion (ICD) and to analyze year-by-year the estimated glomerular filtration rate (eGFR) and morphologic upper urinary tract changes.

PATIENTS AND METHODS

We retrospectively identified 226 patients who had undergone RC and ICD from 1980 to 2008, with regular postoperative follow-up visits. The eGFR was calculated using the Modification of Diet in Renal Disease equation at baseline and during follow-up. A decrease in renal function was defined as > 1 mL/min/1.73 m(2) annually.

RESULTS

The median follow-up period after RC was 91 months (range, 61-235 months). The median eGFR decreased from 66 mL/min/1.73 m(2) (range, 17-139 mL/min/1.73 m(2)) to 59 mL/min/1.73 m(2) (range, 33-102 mL/min/1.73 m(2)). A rapid decline in renal function occurred during the first 2 postoperative years (-9 mL/min/1.73 m(2) and -4 mL/min/1.73 m(2) in the first and second year, respectively), with a moderate to slight decrease in the subsequent years. Urinary obstruction was diagnosed in 51 patients (23%). Among the patients who underwent prompt surgical treatment, we did not find any association with the eGFR decline (P = .8).

CONCLUSION

Patients with urinary ICD have a lifelong risk of chronic kidney disease. Regular monitoring of renal function and the morphologic upper urinary tract will permit early diagnosis and treatment of modifiable factors, avoiding irreversible kidney damage.

Etanercept normalises left ventricular mass in patients with rheumatoid arthritis

BACKGROUND

Cardiovascular mortality is increased in patients with rheumatoid arthritis (RA). RA is associated with an increased left ventricular mass index (LVMI), a strong marker of cardiovascular mortality, and vessel abnormalities. Experimental studies have suggested that tumour necrosis factor α (TNFα) may induce LV hypertrophy.

OBJECTIVE

To study the effect of medium-term (3- and 6-months) treatment with the TNFα inhibitor etanercept (ETN) and synthetic disease-modifying antirheumatic drugs (sDMARDs) on LV morphological features and arterial stiffness in patients with RA.

METHODS

Consecutive female patients with active RA requiring treatment with ETN (n=28) or sDMARDs (n=20) were included. Clinical and biological monitoring, echocardiography and pulse wave velocity (PWV) assessment were performed at inclusion and at 3 and 6 months after the start of treatment. Paired t tests and multivariate linear regression analysis were used.

RESULTS

Mean LVMI tended to be higher at baseline in the ETN group than in the sDMARD group (96.5±19.8 vs 84.3±26.8 g/m2; p=0.11 for the ETN and sDMARD groups, respectively). In patients with ETN treatment, mean LVMI was significantly decreased at 3 and 6 months (-6.3±7.6 and -14.2±9.3 g/m2; p<0.001), with no change from baseline for patients with sDMARD treatment (-2.2±10.9 and -2.7±10.2 g/m2, respectively). Blood pressure (BP) and aortic PWV were not changed by either treatment.

CONCLUSIONS

ETN induced a significant decrease in LVMI with medium-term treatment with no change in BP or PWV. TNFα may be an important factor of LV hypertrophy, which may explain the benefit of TNF inhibitors on cardiovascular morbidity and mortality in RA. These results need to be confirmed by larger studies and with other TNF inhibitors.

Retinal vascular caliber is associated with renal function in apparently healthy subjects

PURPOSE

To assess the relation between retinal vascular caliber and renal function.

PATIENTS AND METHODS

Eighty apparently healthy subjects screened for cardiovascular risk factors (mean age 47 years, 51% female, 36% hypertensive, without diabetes or renal dysfunction) were recruited. Retinal vascular calibers were measured from fundus photographs and expressed as central retinal artery and venular equivalent. Renal function was assessed by measurement of glomerular filtration rate (urinary clearance of 99mTc-DTPA) and urinary albumin/creatinine ratio.

RESULTS

Mean glomerular filtration rate was 117 ml/min/1.73m(2). Overall, central retinal artery and venular equivalent were positively correlated with glomerular filtration rate (r = +0.31, p = 0.005 and r = +0.30, p = 0.006, respectively). In addition, central retinal artery equivalent was negatively correlated with urinary albumin/creatinine ratio (r = -0.34, p = 0.002). No significant relationship was found between central retinal venular equivalent and urinary albumin/creatinine ratio (r = +0.12, p = 0.32). The observed relations between retinal vascular calibers and renal function parameters remained significant after adjusting for potential confounding factors.

CONCLUSION

In apparently healthy subjects with normal renal function, retinal arteriolar and venular calibers were negatively correlated with kidney function, suggesting common determinants of these preclinical target organ damages.

Exercise aortic stiffness: reproducibility and relation to end-organ damage in men

Resting aortic stiffness (pulse wave velocity; aortic PWV (aPWV)) independently predicts end-organ damage and mortality. Exercise haemodynamics have been shown to unmask cardiovascular abnormalities, otherwise undetectable at rest, but the response of aPWV to exercise has never been examined. This study aimed to develop a technique to measure exercise aPWV, determine reproducibility and relation to subclinical end-organ damage with aging. Healthy younger (n=17, 30±8 years) and older (n=18, 54±8 years) untreated men underwent cardiovascular assessment at rest and during low intensity semirecumbent cycling. Tonometry was used to assess aPWV and central blood pressure (BP). All participants underwent 24 h ambulatory BP (ABP) monitoring. Kidney function was assessed by estimated glomerular filtration rate (eGFR). Fifteen participants had testing repeated within 28±18 days. Exercise aPWV had good reproducibility (mean difference=-0.35±0.61 m s(-1), intraclass correlations=0.874, P<0.001) and was increased 26% above resting values in younger men (5.8±0.9 vs 7.3±1.6 m s(-1), P<0.001) and 19% above resting values in older men (6.3±1.0 vs 7.4±0.9 m s(-1), P<0.001). Exercise, but not resting, aPWV was significantly correlated with eGFR in older men (r=-0.633, P=0.005), and this was maintained after correction for age, body mass index and daytime systolic ABP (r=-0.656, P=0.008). Conversely, in younger men there was no significant association between eGFR and aPWV either at rest (r=-0.031, P=0.906) or during exercise (r=-0.117, P=0.655). Exercise aPWV is reproducible and significantly associated with kidney function in healthy older men. Further studies to determine the physiology and clinical relevance of raised exercise aPWV are warranted.

Treatment of hypertension with renin-angiotensin system inhibitors and renal dysfunction: a systematic review and meta-analysis

BACKGROUND

To determine whether inhibitors of the renin-angiotensin system (RAS) reduce the incidence of renal dysfunction when compared to other antihypertensive treatments in patients with essential hypertension and no pre-existent renal disease.

METHODS

The search strategy used the Cochrane Library, Medline, previous meta-analyses, and journal reviews. The selection criteria included randomized, controlled trials of antihypertensive drugs that compared a RAS inhibitor with another treatment in essential hypertension. Studies that specifically enrolled only patients with diabetes or renal disease were not included. The quality assessment and data extraction of studies were performed by two independent reviewers. Effects on dichotomous renal outcome (serum creatinine (SCreat) higher than a prespecified value, doubling of SCreat or end-stage renal disease) and secondary continuous marker of renal outcome (change in SCreat) were calculated using Peto's method.

RESULTS

33,240 patients met the inclusion criteria for studies with a dichotomous outcome and 10,634 patients for studies with a continuous outcome. The mean follow-up was 42 ± 13 months. Patients randomized to RAS inhibitors did not show a significant reduction in the risk of developing renal dysfunction as compared to other antihypertensive strategies (odds ratio = 1.05; 95% confidence interval (CI) 0.89-1.25; P = 0.54). There was no significant difference in change of SCreat between groups (mean difference = 0.0005 mg/dl; 95% CI -0.0068 to 0.0077 mg/dl; P = 0.91).

CONCLUSION

In patients with essential hypertension and no pre-existent renal disease, prevention of renal dysfunction is not significantly different with RAS inhibitors when compared to other antihypertensive agents.

Association of increased arterial wave reflections with decline in renal function in chronic kidney disease stages 3 and 4

BACKGROUND

Increased arterial wave reflections predict cardiovascular events in dialysis patients. Their impact on the progression of renal disease has not been determined.

METHODS

We prospectively quantified wave reflections as pressure augmentation (AP) and augmentation index (AIx) using radial applanation tonometry and a transfer function, in 111 patients (mean age 53.6 years; 71 men, 31 diabetics) with chronic kidney disease not requiring dialysis. Primary endpoint was a composite of doubling of serum creatinine, need for dialysis, and transplantation. Secondary endpoint was a combination of renal and cardiovascular events.

RESULTS

After a mean follow-up of 41.3 months, 37 and 46 patients reached the primary and the secondary endpoint. AIx and AP proved statistically significant predictors of the renal endpoint (P < 0.05 for all), with a 2.5- and 3-fold increased risk for patients in the highest vs. the lowest tertile, respectively. After adjustment for mean blood pressure (MBP), age, gender, diabetes, serum albumin, hemoglobin, urine albumin/creatinine ratio, and renal function at baseline, AIx (hazard ratio 1.474/10% increase in AIx, P = 0.04) as well as AP (hazard ratio 1.559/10 mm Hg increase in AP, P = 0.04) remained significant predictors of the renal endpoint. In addition, AIx and AP were significant (P < 0.05) predictors of the combined cardiorenal endpoint in univariate analysis and multivariable models.

CONCLUSION

Increased arterial wave reflections are independent predictors of renal as well as cardiorenal events in patients with chronic kidney disease.

Dietary sodium, aldosterone, and left ventricular mass changes during long-term inhibition of the renin-angiotensin system

In essential hypertension, the regression of left ventricular hypertrophy is an important goal of treatment. In addition to treatment-associated changes in blood pressure (BP), the roles of other determinants of left ventricular hypertrophy regression, including dietary sodium intake, deserve investigation. In the present study, the change in echographic left ventricular mass index (LVMI) was assessed in 182 patients with never-treated essential hypertension at baseline and after 3 years of treatment by angiotensin converting enzyme inhibitors or angiotensin II receptor antagonists given at recommended doses and associated with other antihypertensive agents. Treatment was associated with satisfactory control of BP (<140/90 mm Hg) in 64% of patients, and left ventricular hypertrophy prevalence decreased from 56% to 39%. Twenty-four-hour urinary sodium was positively related to LVMI at baseline and at the end of the study, independently of age, sex, and systolic BP. Supine plasma aldosterone concentration was correlated with LVMI only at baseline but not in multivariate analysis. In response to treatment, the percentage of change in LVMI was positively correlated with the absolute changes in systolic BP, urinary sodium, and plasma aldosterone concentration, independently of baseline LVMI. The population was divided into 3 tertiles according to final values of gender-specific urinary sodium. When, within each urinary sodium tertile, patients were divided into those with plasma aldosterone concentration below and above the median (11.6 ng/dL), LVMI progressively increased across sodium tertiles only in patients with high plasma aldosterone concentration. Systolic BP was similar across all of the groups. In conclusion, aldosterone requires the presence of high dietary salt for the expression of its unfavorable effect on the heart.

Vascular permeability, blood pressure, and organ damage in primary hypertension

Sub-clinical organ damage is a strong independent predictor of cardiovascular mortality in primary hypertension, and its changes over time parallel those in risk of cardiovascular events. A better understanding of the pathogenetic mechanisms underlying the development of target organ damage may help us devise more effective therapeutic strategies. We therefore investigated the relationship between the presence of organ damage and some of its potential determinants, such as blood pressure severity and early atherosclerotic abnormalities. Thirty-seven untreated, non-diabetic hypertensive patients were enrolled. Target organ damage was assessed by albuminuria and left ventricular mass index; systemic vascular permeability was evaluated by transcapillary escape rate of albumin (TERalb); and blood pressure was measured by 24h ambulatory blood pressure monitoring. The albumin-to-creatinine ratio and left ventricular mass index were directly related to TERalb (r = 0.48, p = 0.003 and r = 0.39, p < 0.020, respectively) and 24-h systolic blood pressure values (r = 0.54, p < 0.001; r = 0.60, p < 0.001). The simultaneous occurrence of increased blood pressure load and TERalb was associated with higher left ventricular mass index values (p = 0.012) and entailed an increased risk of having at least one sign of damage (chi2 = 17.4; p < 0.001). Logistic regression analysis showed that the risk of presenting at least one sign of organ damage increased more than ten-fold when TERalb was above the median and more than five-fold with each 10 mmHg increase in 24-h systolic blood pressure. Blood pressure load and vascular permeability are potentially modifiable factors that are independently associated with the occurrence of sub-clinical signs of renal and cardiac damage in hypertensive patients.

Hypertensive renal vascular disease and cardiovascular endpoints

PURPOSE OF REVIEW

Hypertension involves the entire cardiovascular system, and hypertensive vascular disease may promote and exacerbate cardiac and renal dysfunction. We discuss the coexistence of cardiorenal disease as a manifestation of vascular involvement in hypertension, and the relationship of biomarkers of renal vascular involvement in hypertension with cardiovascular endpoints.

RECENT FINDINGS

Markers of renal dysfunction, especially microalbuminuria, have been considered recently as potent predictors of cardiovascular morbidity and mortality in all explored populations, including hypertensive individuals. Microalbuminuria, per se, is related to vascular injury and to the increased glomerular permeability of albumin as a direct manifestation of renal vascular involvement in hypertension, a systemic vascular disease. Left ventricular hypertrophy in hypertension develops even before proteinuria or impairment of renal function. Factors including anemia, inflammation and hyperuricemia are either induced or exacerbated by renal vascular disease, and each of these may exert additional influence in determining the increased incidence of cardiovascular events with progressive renal dysfunction.

SUMMARY

The development and progression of vascular disease is the primary determinant in the progressive cardiac and renal dysfunction observed in hypertension and, therefore, is the underlying mechanism of the overall clinical manifestations of cardiorenal disease. Commonly used biomarkers of renal and vascular function are important tools for determination of the progression and, hence, management of hypertensive disease and its complications.

Pulse pressure is an independent determinant of renal function decline during treatment of essential hypertension

BACKGROUND

In large epidemiological studies and using serum creatinine or estimates of glomerular filtration rate (GFR), blood pressure has emerged as a predominant determinant of the age-associated decline in renal function.

METHODS

The present longitudinal study (median follow-up period of 5.8 years) was conducted in 132 never-treated patients with essential hypertension at baseline. The effect of treatment on the GFR and effective renal plasma flow, estimated by urinary clearances of isotopic markers, was assessed.

RESULTS

Satisfactory control of hypertension (<140/90 mmHg) was achieved in 57% of the population. During follow-up, the yearly change in the GFR was -1.72+/-0.21 ml/min per year (mean+/-SEM). In univariate regression analysis, the change in the GFR was correlated with baseline pulse pressure (r=-0.27, P=0.002), whereas no influence of systolic, diastolic or mean blood pressures, as well as baseline albuminuria or left ventricular mass index, was found. Multivariate logistic regression analysis showed that only baseline pulse pressure conveyed a significant odds ratio of accelerated decline of GFR (>median of 1.5 ml/min per year), independently of age, baseline GFR, mean blood pressure and other known cardiovascular risk factors. No influence of the type of antihypertensive treatment (64% of the population had received angiotensin-converting enzyme inhibitor) was detected.

CONCLUSION

Pulse pressure (a marker of arterial stiffening) is suggested as an independent determinant of the treatment-associated decline in renal function in essential hypertension. No influence of target organ damage (albuminuria of left ventricular hypertrophy) was detected.

The natural history of postoperative renal function in patients undergoing ileal conduit diversion for cancer measured using serial isotopic glomerular filtration rate and 99m technetium-mercaptoacetyltriglycine renography

PURPOSE

There is little consensus regarding long-term followup of renal function in patients who undergo urinary diversion. We established the usefulness of combined serial isotopic glomerular filtration rate measurement and diuresis renography in the early identification of patients at risk for deterioration of renal function following ileal conduit diversion.

MATERIALS AND METHODS

A total of 340 patients with ileal conduit diversion who were followed between 1990 and 2000 were identified. We analyzed data on 178 patients who had more than 4 years of followup. Renal function was assessed by serial estimation of serum creatinine, isotopic glomerular filtration rate and diuresis renographic measurements.

RESULTS

Of the patients 52 (29%) demonstrated a worsening glomerular filtration rate. Mean followup +/- SEM was 8.2 +/- 0.4 years (range 4 to 30) and 67% of patients had more than 6 years of followup. In this group we found that hypertension, recurrent urinary sepsis and an initial post-diversion glomerular filtration rate of less than 50 ml per minute per 1.73 m were prevalent risk factors. Hypertension was an independent predictor of a decreased glomerular filtration rate in this group. Of 52 patients with a deteriorating glomerular filtration rate 19 had type II or IIIb curves on followup renography, of whom 13 underwent revision surgery. Renal function subsequently stabilized or improved in this group.

CONCLUSIONS

Of patients with an ileal conduit 29% have renal function deterioration in the long term. No surgical cause for glomerular filtration rate deterioration was found in 18%. Important predisposing factors in nonobstructed cases were hypertension, recurrent urinary sepsis and a glomerular filtration rate of less than 50 ml per minute per 1.73 m. Hypertension was an independent predictor of a decreased glomerular filtration rate in the group with worsening glomerular filtration rates. In 11% of patients deterioration was due to upper tract obstruction. This was identifiable using renography and the glomerular filtration rate. A type IIIb curve was an early indicator of obstruction.

Controversies in hypertension

Hypertension remains the most common risk factor for cardiovascular morbidity and mortality. Its incidence is rising in both ageing and obese populations, but its control remains inadequate worldwide. We address several persisting controversies that may interfere with appropriate management of hypertension. They include: the reasons behind the increasing incidence of hypertension and the possible ways to slow the process, especially by lifestyle changes; the need for overall cardiovascular risk assessment; the major issues in the decision to institute drug therapy and the choice of drugs; and the importance of screening for various identifiable causes. We provide the background for these controversies, followed by some opinions on how to guide practitioners to offer more effective management of hypertension.