Hypertension after liver transplantation: a predictive role for pretreatment hemodynamics and effects of isradipine on the systemic and renal circulations

Treatment of Hypertension Because of Immunosuppressive Therapy After Solid Organ Transplantation-Pharmacological Approach

ABSTRACT

Solid organs transplantation procedures have been performed for more than half a century. Growing knowledge of immune response and development of new immunosuppressive regimens guarantee more and more successful outcomes. However, many of the applied drugs lead to cardiovascular complications, the most frequent of which is hypertension. This article describes epidemiology, pathogenetic mechanisms, and treatment of hypertension induced by immunosuppressive medication. The main impact is focused on drugs belonging to the following groups: calcineurin inhibitors, the inhibitors of the mammalian target of rapamycin, and glucocorticosteroids. We analyze the mechanism of action of the main hypertensive drugs and their influence on the reversing hypertonic action of the immunosuppressive agents. In the absence of current guidelines addressing this problem, this article is an attempt to fill the gap, helping clinicians to choose proper medication.

Tacrolimus Predose Concentration Is Associated With Hypertension in Pediatric Liver Transplant Recipients

BACKGROUND

The aim of the study was to analyze the incidence of hypertension in pediatric liver transplantation (LT) recipients using ambulatory blood pressure measurements (ABPM) and to identify factors associated with hypertension. We also investigated whether hypertension or tacrolimus predose concentration (TAC C0) was associated with increased left ventricular (LV) wall thickness.

PATIENTS AND METHODS

On a retrospective longitudinal base, we included 39 pediatric LT recipients. Median time since transplantation was 65 months (range: 11-183). Two consecutive ABPM were analyzed with a median time interval of 13 months. Data from echocardiographic evaluation parallel to the baseline ABPM were analyzed. All patients except 1 were prescribed tacrolimus. The median TAC C0 was 4 ng/mL (range 0.9-11.2). Univariate and multivariate logistic regression models were fitted to identify factors associated with systolic and diastolic hypertension and LV wall thickness.

RESULTS

Twenty-two of 39 children were hypertensive at baseline and 19 of 32 were hypertensive at follow-up. At baseline 10 (26%) children had masked systolic hypertension. TAC C0 was associated with systolic (P = 0.007, Exp(B) 2.02, 95% CI 1.2-3.3) and diastolic (P = 0.044, Exp(B) 1.48, 95% CI 1.0-2.2) hypertension. LV wall thickness was increased in children after LT compared with healthy population, but it was not associated with hypertension or TAC C0.

CONCLUSIONS

Given the high prevalence of masked hypertension, ABPM should be performed in all pediatric LT recipients. Systolic and diastolic hypertension is associated with TAC C0; therefore, children with a higher target TAC C0 require a more intensive blood pressure surveillance.

Hypertension: The Neglected Complication of Transplantation

Arterial hypertension and transplantation are closely linked, and its association may promote impaired graft and overall survival. Since the introduction of calcineurin inhibitors, it is observed in 50–80% of transplanted patients. However, many pathophysiological mechanisms are involved in its genesis. In this review, we intend to provide an updated overview of these mechanisms, dealing with the causes common to all kinds of transplantation and emphasizing special cases with distinct features, and to give a perspective on the pharmacological approach, in order to help clinicians in the management of this frequent complication.

Control of blood pressure in liver transplant recipients

BACKGROUND

Increased blood pressure (BP) is common after liver transplantation. However, there is scarce information on its control.

METHODS

In this prospective, cross-sectional, multicenter study, we determined BP according to the recommended international standards in 921 liver transplant patients during one routine outpatient visit to assess their grade of control of BP. At the time of the study, 490 patients had been previously diagnosed with arterial hypertension and were receiving antihypertensive treatment, and 431 were not previously diagnosed as hypertensive.

RESULTS

In the hypertensive group, arterial hypertension was uncontrolled (BP >140/90 mm Hg [>130/80 in diabetics]) in 158 (32%) patients and controlled in 332 (68%) patients. In a multivariate analysis, only diabetes was identified as a significant predictor of uncontrolled hypertension. Among patients not previously diagnosed as hypertensive, BP was increased in 106 (25%) and normal in 325 (75%). On multivariate analysis, the only variable independently associated with increased BP in this group was metabolic syndrome.

CONCLUSION

BP is not adequately controlled in a noticeable percentage of liver transplant patients, especially in subjects with diabetes or metabolic syndrome.

Disruption of Transitional Stages in 24-h Blood Pressure Recording in Renal Transplant Recipients

Patients with kidney replacement exhibit disrupted circadian rhythms. Most studies measuring blood pressure use the dipper/non-dipper classification, which does not consider analysis of transitional stages between low and high blood pressure, confidence intervals nor shifts in the time of peak, while assuming subjective onsets of night and day phases. In order to better understand the nature of daily variation of blood pressure in these patients, we analyzed 24 h recordings from 41 renal transplant recipients using the non-symmetrical double-logistic fitting assessment which does not assume abruptness nor symmetry in ascending and descending stages of the blood pressure profile, and a cosine best-fitting regression method (Cosinor). Compared with matched controls, double-logistic fitting showed that the times for most transitional stages (ascending systolic and descending systolic, diastolic, and mean arterial pressure) had a wider distribution along the 24-h. The proportion of individuals without daily blood pressure rhythm in the transplanted group was larger only for systolic arterial pressure, and the amplitude showed no significant difference. Furthermore, the transplant recipient group had a less pronounced slope in descending systolic and ascending mean blood pressure. Cosinor analysis confirmed this phase-related changes, showing a wider distribution of times of peak (acrophases). We conclude that daily disruptions in renal transplant recipients can be explained not necessarily by an absence in diurnal variation, but also by changes in waveform-related parameters of the rhythm, and that alterations in the phase of the rhythm are the most consistent finding in these patients.

Medical management of the liver transplant recipient

Long-term survival of liver transplant recipients has become the rule rather than the exception. As a result, the medical complications of long-term survival, including atherosclerotic cardiovascular disease, metabolic bone disease, and de novo malignancy, have accounted for an increasing proportion of late morbidity and mortality. Risk factors for these complications begin before transplant and are potentially modifiable but are exacerbated by the requirement for immunosuppressive medications after transplantation. Surveillance and early intervention programs administered by transplant hepatologists and other medical subspecialists may improve long-term outcomes in liver transplant recipients by ameliorating risk factors for atherosclerosis, bone fractures, and cancer.

Increased vascular resistance and not salt retention characterizes cyclosporine A-induced hypertension: report in an anuric patient

Cyclosporine A (CsA) use is associated with hypertension in most solid-organ transplant recipients. The mechanisms of CsA-induced hypertension have not been fully elucidated and are still controversial. We present a case of CsA-induced hypertension who was anuric and receiving hemodialysis, and in whom noninvasive cardiothoracic bioimpedence revealed elevated systemic vascular resistance without evidence of fluid-volume overload. We briefly discuss the possible mechanisms of CsA-induced hypertension in light of this information.

Reducing the risks of cardiovascular disease in liver allograft recipients

Liver allograft recipients are at increased risk of death from cerebrovascular and cardiovascular disease. We propose the following strategy of risk-reduction, based on currently available literature. Lifestyle: standard advice should be given (avoidance of smoking, excess alcohol and obesity, adequate exercise, reduction of excess sodium intake). Hypertension: target blood pressure should be 140/90 mmHg or lower, but for those with diabetes or renal disease, 130/80 mmHg or lower. For patients without proteinuria, antihypertensive therapy should be initiated with a calcium channel blocker and for those with proteinuria, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker. If monotherapy fails to achieve adequate response, calcium channel blockers and ACE-inhibitors or angiotensin II receptor blockers should be combined. If hypertension remains uncontrolled, an alpha-blocker may be added. Consideration should be given to changing immunosuppression and avoiding use of calcineurin inhibitors. Diabetes: recipients should be regularly screened for diabetes. For patients with new-onset diabetes after transplant, stepwise therapy should be guided by HbA1c concentrations, as with type II diabetes mellitus. Hyperlipidemia: annual screening of lipid profile should be undertaken, with treatment thresholds and targets based on those advocated for the high risk general population. Dietary intervention is appropriate for all patients. A statin should be considered as the first line treatment to achieve specified targets. In patients receiving a calcineurin inhibitor, Pravastatin should be commenced at a dose of 10 mg/day. In patients receiving other forms of immunosuppression, pravastatin may be commenced at a dose of 20 mg/day. Liver tests should be monitored and patients warned to report myalgia. If monotherapy is inadequate, ezetimibe or a fibrate may be added. Consideration may be given to change in immunosuppression if combination lipid-lowering therapy proves inadequate.

Cardiovascular risk factors after liver transplantation

1. Yearly screening of liver recipients with serum cholesterol, triglycerides, and lipoproteins, and assessment for risk factors for atherosclerotic cardiovascular disease, is an important component of comprehensive post transplant care. 2. Revised guidelines and target levels of LDL-cholesterol levels specific for moderate and high cardiovascular risk patients have been recently revised. 3. Transplant physicians should be aware of advances in the management of post transplant arterial hypertension, diabetes mellitus, obesity, and nicotine dependence.

Hemodynamic effects of amlodipine, bisoprolol, and lisinopril in hypertensive patients after liver transplantation1

BACKGROUND

Hypertension is common after liver transplantation. There are few published data on optimum treatment. Augmentation index (AIx) is a measure of arterial wave reflection determined by pulse wave analysis.

METHODS

Amlodipine was administered to 24 hypertensive liver transplant recipients. Thirteen patients intolerant of or unresponsive to amlodipine were randomized to a crossover study comparing bisoprolol with lisinopril.

RESULTS

With amlodipine, systolic blood pressure (SBP) fell from 154+/-2 mm Hg to 130+/-2 mm Hg, and AIx also fell. With bisoprolol, SBP fell from 154+/-2 mm Hg to 142+/-4 mm Hg, but AIx increased. With lisinopril, SBP fell from 154+/-2 mm Hg to 130+/-5 mm Hg, and AIx also fell (P <0.001 throughout).

CONCLUSIONS

Amlodipine is an effective treatment for hypertension. The increased AIx with bisoprolol indicates increased wave reflection such that central aortic pressure is reduced less than peripheral SBP. Lisinopril reduces AIx and reduces SBP more than bisoprolol and is the preferred drug.

Acute renal failure in hospitalized patients: part II

BACKGROUND

Acute renal failure (ARF) is a common condition in hospitalized patients. Research has been unable to identify the optimal target for therapeutic intervention; hence, effective prevention of and/or treatment for ARF remain elusive.

OBJECTIVE

To examine the usefulness of current and potential pharmacologic treatments in seriously ill, hospitalized patients.

DATA SOURCES

A MEDLINE search (1996-June 2002) was conducted using the search terms kidney (drug effects) and acute kidney failure (drug therapy). Bibliographies of selected articles were also examined to include all relevant investigations.

STUDY SELECTION AND DATA EXTRACTION

Review articles, meta-analyses, and clinical trials describing prevention of and treatment for hospital-acquired ARF were identified. Results from prospective, controlled trials were given priority when available.

CONCLUSIONS

Appropriate management of ARF includes prospective identification of at-risk patients, fluid administration, and optimal hemodynamic support. Drug treatments, including low-dose dopamine and diuretics, have demonstrated extremely limited benefits and have not been shown to improve patient outcome. Experimental agents influence cellular processes of renal dysfunction and recovery; unfortunately, relatively few drugs show promise for the future.

Sympathetic neural mechanisms in normal and hypertensive pregnancy in humans

BACKGROUND

Direct recordings from peripheral sympathetic nerves have shown an increased sympathetic drive in pregnancy-induced hypertension (PIH) and preeclampsia (PE). It is unknown whether sympathetic drive is altered in normal pregnancy, when arterial blood pressure can be normal or relatively low. The aim of this study was to measure and compare peripheral sympathetic discharge, its vasoconstrictor effect and its baroreceptor control, during pregnancy and postpartum in women with normal pregnancy (NP) and PIH and in normotensive nonpregnant (NN) women.

METHODS AND RESULTS

Twenty-one women with NP, 18 women with PIH, and 21 NN women had muscle sympathetic nerve activity assessed from multiunit discharges (MSNA) and from single units with defined vasoconstrictor properties (s-MSNA). The s-MSNA in NP (38+/-6.6 impulses/100 beats) was greater (P<0.05) than in NN women (19+/-1.8 impulses/100 beats) despite similar age and body weight but less than in PIH women (P<0.001) (146+/-23.5 impulses/100 beats). MSNA followed a similar trend. Cardiac baroreceptor reflex sensitivity (BRS) was impaired in NP and PIH women relative to NN. After delivery, sympathetic activity decreased to values similar to those obtained in NN, and there was an increase in BRS. In women with NP, the decrease in sympathetic output occurred despite an insignificant change in blood pressure.

CONCLUSIONS

Central sympathetic output was increased in women with normal pregnancy and was even greater in the hypertensive pregnant group. The findings suggest that the moderate sympathetic hyperactivity during the latter months of normal pregnancy may help to return the arterial pressure to nonpregnant levels, although when the increase in activity is excessive, hypertension may ensue.