Treatment of hyperlipidemia in cardiac transplant recipients

Value of blood lipid in predicting graft dysfunction after organ and tissue transplantation: A study of Mendelian randomization

Background

While immunosuppressive regimens have improved outcomes in solid organ transplantation, non-immune factors have also been identified as contributors to graft prognosis. Age, gender, hormones, heredity, and other diseases have been recognized to affect organ transplantation. However, the causal relationship between blood lipids and graft dysfunction remains unverified in human clinical investigations. In this study, we employed two-sample Mendelian randomization (MR) to examine the causality between different types of blood lipids and graft dysfunction following organ and tissue transplantation.

Methods

We conducted a two-sample MR study using available genome-wide association summary data from the online database MRBASE (http://app.mrbase.org/), which encompasses over 11 billion associations between genetic factors and health-related outcomes, enabling researchers to explore various potential determinants of poor health. The exposure factors included four types of blood lipids: high-density lipoprotein, low-density lipoprotein, cholesterol, and triglycerides. For each exposure factor, three databases were selected for analysis. The outcome factor was the failure and rejection of transplanted organs and tissues. All databases consisted of European population samples, without specific subgroups. The related studies were conducted between 2016 and 2022, and the "TwoSampleMR" R package was employed for variant selection.

Results

A total of 13 sample groups were collected and analyzed. The results revealed a causal association between blood lipids and graft dysfunction following organ and tissue transplantation. Specifically, the two-sample MR analysis confirmed that low-density lipoprotein and cholesterol levels were significant risk factors for increased graft dysfunction risk after transplantation. Moreover, high-density lipoprotein potentially reduced the risk of allograft dysfunction, while triglycerides possibly elevated the risk.

Conclusions

Our recent study provides the initial confirmation that blood lipids may initiate causal pathological processes leading to graft dysfunction after organ and tissue transplantation.

Mycophenolate mofetil-induced hyperlipidemia with cutaneous manifestations

We report a case of a 49 year old woman who developed biopsy-proven xanthomas on her hands and arms after initiation of Mycophenolate mofetil therapy for systemic lupus erythematosus (SLE) and subsequently went into remission upon cessation of the medication.

Long-term changes in body weight and serum cholesterol in heart transplant recipients

INTRODUCTION

Long-term changes in weight and blood lipids beyond 12 months after heart transplantation are largely unknown. We quantified changes in weight, body mass index (BMI), blood cholesterol, and triglycerides in heart transplant recipients (HTRs) during the 36 months after transplantation, and we assessed the influence of statin therapy on these outcomes.

METHODS

Retrospective cohort study of adult HTRs, transplanted 1990-2017, in Queensland, Australia. From each patient's medical charts, we extracted weight, total cholesterol, triglycerides, and statin therapy at four time-points: time of transplant (baseline), and 12-, 24-, 36-month post-transplant. Changes in weight and blood lipids were assessed according to baseline BMI.

RESULTS

Among 316 HTRs, 236 (median age 52 years, 83% males) with available information were included. During the 36 months post-transplant, all patients gained weight (83.5-90.5 kg; p < .001), especially those with baseline BMI < 25.0 km/m2 (67.9-76.2 kg; p < .001). Mean blood cholesterol (4.60-4.90 mmol/L; p = .004) and mean blood triglycerides (1.79-2.18 mmol/L; p = .006) also increased significantly in all patients, particularly in those with baseline BMI ≥ 25.0 km/m2 but the differences were not significant (total cholesterol 4.42-5.13 mmol/L; triglycerides 1.76-2.47 mmol/L). Total cholesterol was highest in patients not taking statins, and levels differed significantly (p = .010) according to statin dosing changes during the 36 months post-transplant.

CONCLUSION

Patients demonstrate significant rises in weight and blood lipids in the 36 months after heart transplantation.

Changes in body weight and serum cholesterol after heart transplant in relation to ventricular assist device implantation

Weight gain is common after implantation of a ventricular assist device (VAD) prior to heart transplantation, but post-transplant changes in weight and also in blood lipids in those with VAD is virtually unknown. This study aimed to determine the influence of pre-transplant VAD implantation on body weight, blood cholesterol and triglyceride levels in Australian adult heart transplant recipients (HTRs), 1990-2017, from time of transplantation to 36 months post-transplantation. Information on VAD implantation, weight and blood lipids was collected for HTRs from medical records. Changes in weight and blood lipids from post-transplant to 12-, 24 and 36 months later, were assessed by VAD status using linear mixed-effects models. Of 236 heart transplant recipients, 48 (20%) had VAD implants. HTRs irrespective of VAD status, tended to increase their mean weight (p < 0.001) over 36 months (VAD implant: 76.9-84.4 kg; no VAD: 81.3-88.2 kg). Patients with VAD tended to have lower mean blood lipids but experienced increases similar to those with no VAD, from baseline to 36 months (cholesterol: VAD: 4.24-4.66 mmol/l; no VAD: 4.73-4.88 mmol/l; p = 0.05; triglycerides: VAD 1.59-1.63 mmol/l; no VAD 1.85-2.22 mmol/l; p = 0.09). We conclude that HTRs in general experience weight gain and lipid increases in the first 36 months after transplantation, regardless of prior VAD implantation.

Management of dyslipidemia after allogeneic hematopoietic stem cell transplantation

Dyslipidemia is one of the complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT), and it is often underestimated and undertreated. Dyslipidemia in allo-HSCT recipients has been confirmed to be associated with endocrine dysfunction, acute and chronic graft-versus-host disease (aGVHD and cGVHD), immunosuppressive agent application, etc. However, few studies have illustrated the accurate molecular signaling pathways involved in dyslipidemia, and there are no standard guidelines for dyslipidemia management after HSCT. This review will discuss the pathogenesis of dyslipidemia, especially the association with aGVHD and/or cGVHD. Comprehensive treatment methods for dyslipidemia after HSCT will also be summarized.

Intravascular ultrasound-guided selection for early noninvasive cardiac allograft vasculopathy screening in heart transplant recipients

BACKGROUND

Noninvasive screening for cardiac allograft vasculopathy (CAV) instead of invasive coronary angiography (ICA) within the first 3 to 5 years after heart transplantation (HTx) is controversial. We evaluated a strategy of intravascular ultrasound (IVUS)-guided conversion to early noninvasive screening post-HTx.

METHODS

A single-center study of 103 consecutive HTx recipients from 2008 to 2018 undergoing ICA at 1 year post-HTx. Of 88 patients with normal 1-year ICA, sixty-six patients underwent IVUS examination for risk stratification by maximal intimal thickness (MIT) into (i) low-risk group (MIT < 0.5 mm) (n = 41, 62%) followed noninvasively versus (ii) high-risk group (MIT ≥ 0.5 mm) (n = 25, 38%) followed with yearly ICA. Both groups underwent ICA at year 5 post-HTx. We evaluated a combined endpoint of angiographic CAV and death at 5-year follow-up post-HTx.

RESULTS

Median (IQR) age was 51 (33-60) years, and 62% were male. Follow-up was 1443 (1125-1456) days. Survival free from angiographic CAV (Kaplan-Meier) differed significantly between groups (log-rank p < .0001). A subgroup of 27 patients completed ICA at year 5, and the proportion of angiographic CAV was significantly lower in low-risk patients (p < .0001).

CONCLUSION

IVUS-guided selection for early noninvasive CAV screening appears to be safe and holds promise as a novel strategy for early risk stratification and CAV surveillance post-HTx.

Hypercholesterolemia after conversion to sirolimus as primary immunosuppression and cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

Sirolimus (SRL) attenuates cardiac allograft vasculopathy (CAV) progression after heart transplantation (HT) but often results in hyperlipidemia. In this study we investigated the differential effects of SRL-based and calcineurin inhibitor (CNI)-based immunosuppression on CAV progression and clinical outcomes in HT recipients.

METHODS

CAV progression was assessed by coronary intravascular ultrasound (IVUS) as changes in volumetric measurements after correction to time between the first and last follow-up IVUS exams. CAV progression rate and CAV-associated events were compared between patients with mean follow-up low-density lipoprotein (LDL) <100 mg/dl (lower level or LL) and ≥100 mg/dl (higher level or HL) in the SRL and CNI groups.

RESULTS

We identified 227 patients on SRL (LL: 118; HL: 109) and 96 on CNI (LL: 56; HL: 40), with a median follow-up of 6.7 years. Clinical characteristics did not differ between the LL and HL groups and all patients were on statins. In the SRL arm, there were no significant differences in CAV progression rate and there were no differences in all-cause mortality and CAV-associated events between the LL and HL groups. In the CNI arm, the Δ change in plaque volume normalized to segment length and time of follow-up (PV/SL/year) (0.55 ± 0.53 vs 1.53 ± 2.32, p = 0.003) and Δ change in plaque index per year (defined as PV/vessel volume ratio) (3.1 ± 3.7% vs 6.3 ± 10.4%; p = 0.034) were significantly lower in the LL than the HL group. After adjusting for patient characteristics, HL was associated with higher rates of advanced CAV requiring coronary angioplasty (hazard ratio [HR] 3.0, 95% confidence interval [CI] 1.05 to 9.40, p = 0.040) and higher rates of all CAV-associated events (HR 2.2, 95% CI 1.10 to 4.54, p = 0.026) in these CNI-treated subjects.

CONCLUSION

Unlike CNI-based immunosuppression, the effects of SRL on attenuating CAV progression are independent of LDL cholesterol levels post-HT.

Timing of 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor initiation and allograft vasculopathy progression and outcomes in heart transplant recipients

Aims

Early studies from the 1990s have shown that statins improve survival and attenuate cardiac allograft vasculopathy (CAV). However, little contemporary data are available on the incremental benefit of statins with the current use of new‐generation immunosuppressive agents and the use of coronary intravascular ultrasound for assessment of CAV. We sought to investigate the effect of early statin (ES) as compared with late statin (LS) initiation after heart transplantation (HT) on long‐term CAV progression and clinical outcomes in a large contemporary HT cohort.

Methods and results

We analysed a cohort of 409 adult HT recipients. CAV progression was assessed by serial coronary intravascular ultrasound volumetric measurements of the differences between baseline and last follow‐up plaque volume (PV) and plaque index (PV/vessel volume ratio). CAV progression and clinical outcomes were compared between the ES (<2 years after HT) and the LS (>2 years after HT) groups. During a median follow‐up of 8.2 years, ES resulted in significantly lower change (Δ) of plaque index (+3.8% ± 1.7% vs. +8.2% ± 3.6%; P = 0.0008) and PV (+0.8 ± 0.3 vs. +1.9 ± 1.2; P = 0.045) compared with LS group. In a Cox proportional hazards regression model and after adjustment for baseline characteristics, ES was associated with a 52% decreased risk of CAV‐associated events (hazard ratio 0.48, 95% confidence interval: 0.27–0.91; P = 0.025) and a 42% decreased risk of the composite endpoint of all‐cause mortality and CAV‐associated events (hazard ratio 0.58, 95% confidence interval: 0.38–0.91; P = 0.019).

Conclusions

Early initiation of statin therapy after HT results in attenuated CAV progression as well as in decreased CAV‐related events and mortality.

Comprehensive morphologic and functional imaging of heart transplant patients: first experience with dynamic perfusion CT

OBJECTIVES

We aimed to assess the diagnostic performance of a combined protocol with coronary computed tomography angiography (CCTA) and stress CT perfusion imaging (CTP) in heart transplant patients for comprehensive morphological and functional imaging.

METHODS

In this prospective study, 13 patients undergoing routine follow-up 8±6 years after heart transplantation underwent CCTA and dynamic adenosine stress CTP using a third-generation dual-source CT scanner, cardiac magnetic resonance (MR) adenosine stress perfusion imaging at 1.5 T, and catheter coronary angiography. In CCTA stenoses >50% luminal diameter narrowing were noted. Myocardial perfusion deficits were documented in CTP and MR. Quantitative myocardial blood flow (MBF) was calculated with CTP. Left ventricular ejection fraction was determined on cardiac MR cine images. Radiation doses of CT were determined.

RESULTS

One of the 13 patients had to be excluded because of severe motion artifacts. CCTA identified three patients with stenosis >50%, which were confirmed with catheter coronary angiography. CTP showed four patients with stress-induced myocardial hypoperfusion, which were confirmed by MR stress perfusion imaging. Quantitative analysis of global MBF showed lower mean values as compared to known reference values (MBF under stress 125.5 ± 34.5 ml/100 ml/min). Average left ventricular ejection fraction was preserved (56 ± 5%).

CONCLUSIONS

In heart transplant patients, a comprehensive CT protocol for the assessment of morphology and function including CCTA and CTP showed good concordance to results from MR perfusion imaging and catheter coronary angiography.

KEY POINTS

• Stress CT perfusion imaging enables the detection of myocardial ischemia • CT myocardial perfusion imaging can be combined with coronary computed tomography angiography • Combining perfusion and coronary CT imaging is accurate in heart transplant patients • CT myocardial perfusion imaging can be performed at a reasonable radiation dose.

Impact of environmental factors on alloimmunity and transplant fate

Although gene-environment interactions have been investigated for many years to understand people's susceptibility to autoimmune diseases or cancer, a role for environmental factors in modulating alloimmune responses and transplant outcomes is only now beginning to emerge. New data suggest that diet, hyperlipidemia, pollutants, commensal microbes, and pathogenic infections can all affect T cell activation, differentiation, and the kinetics of graft rejection. These observations reveal opportunities for novel therapeutic interventions to improve graft outcomes as well as for noninvasive biomarker discovery to predict or diagnose graft deterioration before it becomes irreversible. In this Review, we will focus on the impact of these environmental factors on immune function and, when known, on alloimmune function, as well as on transplant fate.

Post-transplant dyslipidemia: Mechanisms, diagnosis and management

Post-transplant dyslipidemia is highly prevalent and presents unique management challenges to the clinician. The two major outcomes to consider with post-transplant therapies for dyslipidemia are preserving or improving allograft function, and reducing cardiovascular risk. Although there are other cardiovascular risk factors such as graft dysfunction, hypertension, and diabetes, attention to dyslipidemia is warranted because interventions for dyslipidemia have an impact on reducing cardiac events in clinical trials specific to the transplant population. Dyslipidemia is not synonymous with hyperlipidemia. Numerous mechanisms exist for the occurrence of post-transplant dyslipidemia, including those mediated by immunosuppressive drug therapy. Statin therapy has received the most attention in all solid organ transplant recipient populations, although the effect of proper dietary advice and adjuvant pharmacological and non-pharmacological agents should not be dismissed. At all stages of treatment appropriate monitoring strategies for side effects should be implemented so that the benefits from these therapies can be achieved. Clinicians have a choice when there is a conflict between various transplant society and lipid society guidelines for therapy and targets.

[Painless anterior acute myocardial infarction in a transplanted heart]

Cardiac allograft vasculopathy is the major determinant of long-term survival in patients after heart transplantation. Clinical presentations are congestive heart failure, ventricular arrhythmias and sudden cardiac death. Acute coronary syndrome is a rare presentation of cardiac allograft vasculopathy due to myocardial denervation. We present the case of a 31-year-old patient, who had undergone heart transplantation 6 months earlier and who developed a painless anterior myocardial infarction revealed by syncope. He was successfully treated by percutaneous coronary intervention with drug eluting stent implantation.

Cardiac allograft vasculopathy: diagnosis, therapy, and prognosis

Development of cardiac allograft vasculopathy represents the major determinant of long-term survival in patients after heart transplantation. Due to graft denervation, these patients seldom present with classic symptoms of angina pectoris, and the first clinical presentations are progressive heart failure or sudden cardiac death. Although coronary angiography remains the routine technique for coronary artery disease detection, it is not sensitive enough for screening purposes. This is especially the case in the first year after transplantation when diffuse and concentric vascular changes can be easily detected only by intravascular ultrasound. The treatment of the established vasculopathy is disappointing, so the primary effort should be directed toward early prevention and diagnosis. Due to diffuse vascular changes, revascularization procedures are restricted only to a relatively small proportion of patients with favorable coronary anatomy. Percutaneous coronary intervention is preferred over surgical revascularization since it leads to better acute results and patient survival. Although there is no proven long-term advantage of drug-eluting stents for the treatment of in-stent restenosis, they are preferred over bare-metal stents. Severe vasculopathy has a poor prognosis and the only definitive treatment is retransplantation. This article reviews the present knowledge on the pathogenesis, diagnosis, treatment, and prognosis of cardiac allograft vasculopathy.

Use of antioxidants to prevent cyclosporine a toxicity

Cyclosporine A (CsA) is a potent immunosuppressor that is widely used in transplant surgery and the treatment of several autoimmune diseases. However, major side effects of CsA such as nephrotoxicity, hepatotoxicity, neurotoxicity and cardiovascular diseases have substantially limited its usage. Although molecular mechanisms underlying these adverse effects are not clearly understood, there is some evidence that suggests involvement of reactive oxygen species (ROS) . In parallel, protective effects of various antioxidants have been demonstrated by many research groups. Extensive studies of CsA-induced nephrotoxcity have confirmed that the antioxidants can restore the damaged function and structure of kidney. Subsequently, there have appeared numerous reports to demonstrate the positive antioxidant effects on liver and other organ damages by CsA. It may be timely to review the ideas to envisage the relationship between ROS and the CsA-induced toxicity. This review is comprised of a brief description of the immunosuppressive action and the secondary effects of CsA, and a synopsis of reports regarding the antioxidant treatments against the ROS-linked CsA toxicity. A plethora of recent reports suggest that antioxidants can help reduce many CsA’s adverse effects and therefore might help develop more effective CsA treatment regimens.

Effect of ABCB1 genotype on pre- and post-cardiac transplantation plasma lipid concentrations

Genetic variation of ATP-binding cassette subfamily B member 1 (ABCB1) which encodes P-glycoprotein (P-gp) has been associated with lipid levels and response to statins. Here, we studied these associations in patients with advanced heart failure who subsequently underwent transplantation. Fasting total cholesterol (TC), low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglycerides (TG) concentrations in 268 adult heart transplant recipients were analysed retrospectively before and at 1 year after transplantation (n = 176). ABCB1 genotyping and haplotyping for C1236T, G2677T/A and C3435T was performed using polymerase chain reaction. Pre-transplant LDL cholesterol was found to be associated with the C3435T genotype and the G2677T/A-C3435T and C1236T-G2677T/A-C3435T haplotypes. T-allele carriers at all loci (n = 77) had higher LDL levels than non-T-allele carriers (n = 24, 3.5 ± 1.2 vs. 2.8 ± 1.2 mmol/L, respectively, p = 0.025). This association remained after adjustment for age, sex, body mass index, statin use and underlying ischaemic heart disease. ABCB1 genotype was not associated with post-transplant lipid parameters. Hypercholesterolaemia (TC >5.7 mmol/L) was more prevalent post-transplant than pre-transplant (51% vs. 30%, respectively) and was likely related to steroid and calcineurin inhibitor use. Muscle-related statin effects were only seen in patients possessing the T-haplotype. In conclusion, an association between ABCB1 haplotype and plasma fasting LDL cholesterol concentration was found in patients with advanced heart failure. This association was not seen 1 year after cardiac transplantation.

Dyslipidemia after allogeneic hematopoietic stem cell transplantation: evaluation and management

Currently, approximately 15,000 to 20,000 patients undergo allogeneic hematopoietic stem cell transplantation (HSCT) annually throughout the world, with the number of long-term survivors increasing rapidly. In long-term follow-up after transplantation, the focus of care moves beyond cure of the original disease to the identification and treatment of late effects after HSCT. One of the more serious complications is therapy-related cardiovascular disease. Long-term survivors after HSCT probably have an increased risk of premature cardiovascular events. Cardiovascular complications related to dyslipidemia and other risk factors account for a significant proportion of late nonrelapse morbidity and mortality. This review addresses the risk and causes of dyslipidemia and impact on cardiovascular complications after HSCT. Immunosuppressive therapy, chronic graft-versus-host disease, and other long-term complications influence the management of dyslipidemia. There are currently no established guidelines for evaluation and management of dyslipidemia in HSCT patients; in this review, we have summarized our suggested approach in the HSCT population.

Simvastatin induces apoptosis of fibroblast-like synoviocytes

Background:

Statins (3-Hydroxy-3-methylglutaryl-CoA reductase inhibitors) exert favorable effects on lipoprotein metabolism, but appeared to possess anti-inflammatory properties among others, as suggested by their ability to inhibit collagen-induced arthritis in mice. Their activity in fibroblast-like synovial cells (FLS) has not yet been studied.

Objectives:

To evaluate the effect of varying doses of simvastatin on apoptosis of FLS.

Methods:

Synovial tissue, obtained during total knee replacement due to osteoarthritis, was cut into small pieces and cultured in Petri dishes with test materials, as previously described. FLS were incubated for 48 hours with 1 μmol/ml, 5 μmol/ ml, 15 μmol/ml and 50 μmol/ml of simvastatin. Following incubation, apoptosis was analyzed by two-dimensional flow cytometry (FACS) using annexin V/PI staining according to the manufacturer’s instructions.

Results:

Different concentrations of simvastatin induced apoptosis of FLS. The level proportion of apoptotic cells of resting or activated with lipopolysaccharide (LPS; 3 μg/ml) FLS, not treated with simvastatin, was 21%. At 48 hours, the rate of apoptosis of activated fibroblasts, incubated with 1 μmol/ml, 5 μmol/ml, 15 and 50 μmol/ml was 22%, 32%, 48% and 41% respectively. Synovial cell viability evaluated by tetrazolium salt XXT was unaffected by the simvastatin concentration used.

Conclusion:

Varying concentrations of simvastatin induce apoptosis of activated fibroblast-like synoviocytes, suggesting another possible mechanism of anti-inflammatory effects of statins in inflammatory conditions.

Lipid management in chronic kidney disease, hemodialysis, and transplantation

Recent studies have shown the spectrum of dyslipidemia in patients who have chronic kidney disease (CKD) or end-stage renal disease to be different from that of the general population. This article discusses the pathophysiology of dyslipidemia in CKD, dialysis, and renal transplant patients, the therapeutic options, and their association with clinical outcomes. Whenever possible, comparisons are made to outcomes in the general population.

Adverse drug reactions in patients with cardiovascular disease

Adverse drug reactions (ADRs) occur frequently in modern medical practice, increasing morbidity and mortality and inflating the cost of care. Patients with cardiovascular disease are particularly vulnerable to ADRs due to their advanced age, polypharmacy, and the influence of heart disease on drug metabolism. The ADR potential for a particular cardiovascular drug varies with the individual, the disease being treated, and the extent of exposure to other drugs. Knowledge of this complex interplay between patient, drug, and disease is a critical component of safe and effective cardiovascular disease management. The majority of significant ADRs involving cardiovascular drugs are predictable and therefore preventable. Better patient education, avoidance of polypharmacy, and clear communication between physicians, pharmacists, and patients, particularly during the transition between the inpatient to outpatient settings, can substantially reduce ADR risk.

A comparison of the effects of fish oil and flaxseed oil on cardiac allograft chronic rejection in rats

Both fish and flaxseed oils are major sources of different n-3 fatty acids. Beneficial effects of fish oil on posttransplantation complications have been reported. The current study aimed to compare the effects of flaxseed and fish oils in a rat cardiac allograft model. Male Fischer and Lewis rats were used as donors and recipients, respectively, to generate a heterotopic cardiac allograft model. Animals were randomly assigned into three groups and fed a diet supplemented with 1) 5% (wt/wt) safflower oil (control, n = 7), 2) 5% (wt/wt) flaxseed oil ( n = 8), or 3) 2% (wt/wt) fish oil ( n = 7), and an intraperitoneal injection of cyclosporine A (CsA; 1.5 mg·kg−1·day−1) over 12 wk. Body weight, blood pressure, plasma levels of lipids, CsA, select cytokines, as well as graft function and chronic rejection features were assessed. Body weight and blood CsA levels were similar among the groups. Relative to controls, both treated groups had lower systolic and diastolic blood pressure and plasma levels of macrophage chemotactic protein-1. Treatment with fish oil significantly ( P < 0.05) lowered plasma levels of triglycerides, total cholesterol, and LDL-cholesterol. HDL-cholesterol concentrations were significantly higher ( P < 0.05) in the flaxseed oil-treated group compared with the other two groups. Both flaxseed oil and fish oil may provide similar biochemical, hemodynamic, and inflammatory benefits after heart transplantation; however, neither of the oils was able to statistically significantly impact chronic rejection or histological evidence of apparent cyclosporine-induced nephrotoxicity in this model.

Ezetimibe in Heart Transplantation: Initial Experience

Dyslipidemia is a common problem among heart transplant (HT) recipients; it is a frequent risk factor in these patients that is exacerbated by immunosuppressive drugs. Statins are effective drugs to treat dyslipidemia in HT recipients, but control is suboptimal in some patients. Ezetimibe acts through inhibition of the enterohepatic recirculation, a mechanism different from but complementary to statins. Our objective was to assess the effect of the addition of ezetimibe to statin therapy among a population of HT patients.

PATIENTS AND METHODS

We included 19 stable patients on statin therapy with suboptimal control of cholesterol. Determinations were performed at baseline on statins and at 6 months (statins + ezetimibe). The analyzed variables were total cholesterol and fractions, triglycerides, cyclosporine levels, CPK, SGOT/SGPT, and bilirubin. The statistics were Student's t test for paired samples.

RESULTS

The overall mean age was 59 +/- 9 years with 95% males and mean BMI 27.5 +/- 3.5. The time since HT was 7 +/- 3 years. The reason for HT included ischemic heart disease in 68%. Pre-HT risk factors included in arterial hypertension in 32% and insulin-dependent diabetes mellitus in 10%, Dyslipidemia occurred in 68%; hypertriglyceridemia in 16% and hyperuricemia in 21%. Immunosuppression was cyclosporine in 100% and steroids in 94%. Type of lipid-lowering agent was simvastatin in 5%; pravastatin, 32%; atorvastatin, 58%; fibrates, 10%. The ezetimibe dose was 10 mg/day in 95% of cases. When ezetimibe was added we observed differences in total cholesterol values (total cholesterol at baseline: 279 +/- 74, total cholesterol with ezetimibe: 198 +/- 47 mg/dL; P = .0001) and LDL-cholesterol values (LDL-cholesterol at baseline: 171 +/- 69, LDL-cholesterol with ezetimibe: 109 +/- 41 mg/dL; P = .001). The remaining variables did not show significant differences.

CONCLUSION

The addition of ezetimibe to statin therapy among heart transplant patients was effective to control dyslipidemia and showed an excellent safety profile.

Low HDL-C predicts the onset of transplant vasculopathy in pediatric cardiac recipients on pravastatin therapy

The levels and protein/lipid compositions of major lipoprotein particles of 19 pediatric cardiac transplant recipients (4-18 yr of age) were studied in this prospective, open clinical follow-up study before and at one yr of pravastatin therapy (10 mg/day). The recipients were grouped into those with (n = 6; group A) and those without (n = 13; group B) angiographically detectable vasculopathy. Twenty-one pediatric non-transplant controls were studied at baseline. At baseline, the group A recipients had 29% lower HDL-C concentrations (p = 0.031) and 29% higher apoB-100/apoA-I ratios (p = 0.034) than the group B recipients. At one yr of pravastatin, the respective figures were 29% (p = 0.013) and 33% (p = 0.005). Compared with the healthy pediatric controls, the transplant recipients had significantly higher serum TG before pravastatin [median (range): 1.3 mmol/L (0.6-3.2) vs. 0.7 mmol/L (0.3-2.4), p = 0.0002] and at one yr [1.3 mmol/L (0.5-3.5) vs. 0.7 mmol/L (0.3-2.4), p = 0.0004]. The baseline apoB-100/apoA1 ratios of the recipients were 33% higher (p = 0.005). In conclusion, low HDL-C and high apoB-100/apoA-I ratio were associated with angiographically detectable vasculopathy. Even though pravastatin effectively lowered the TC and LDL-C and improved compositional properties of LDL and HDL(2) particles, it failed to normalize the elevated TG and, in some patients, to prevent the progression of transplant vasculopathy.

Treatment of Hypercholesterolemia With Ezetimibe in Cardiac Transplant Recipients

The purpose of this study was to examine the efficacy and tolerability of ezetimibe in cardiac transplant recipients who were intolerant of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) or unable to reach target lipid levels with statin therapy. After treatment with ezetimibe (n = 16), mean total and low-density lipoprotein cholesterol levels decreased significantly (228 +/- 40 mg/dl to 197 +/- 48 mg/dl, p = 0.003; and 149 +/- 34 mg/dl to 117 +/- 39 mg/dl, p < 0.001, respectively). One patient required a reduction in ezetimibe dose owing to myalgias; no other adverse events occurred. This initial experience indicates that ezetimibe is well tolerated in cardiac transplant recipients and is effective in reducing total and low-density lipoprotein cholesterol levels.

Safety of Statins When Response is Carefully Monitored: A Study of 336 Heart Recipients

BACKGROUND

Statins are used as first-line drugs against hypercholesterolemia after heart transplantation. Randomized clinical trials have shown that they reduce cholesterol levels, and the incidence of rejection and coronary vasculopathy. Adverse effects have been related to the use of certain statins, high statin dosages, comorbidities, and coadministration with cyclosporine. However, estimation of the risk of adverse effects for a given patient is difficult. The aims of this study were to determine the incidence of various kinds of adverse effect of statins; to evaluate certain potential risk factors; and to assess the efficacy of early response to signs of adverse effects.

METHODS

Between April 1991 and December 2003, we retrospectively evaluated 336 heart transplant patients (including 55 women) with regard to the occurrence of possible adverse effects of statins (rhabdomyolysis, myalgia, hepatotoxicity, high CK without muscle symptoms, and others). Resolution on reduction of dosage or discontinuance and/or change of statin were deemed to constitute confirmation of cause. Relations were sought between adverse effects and age, sex, immunosuppressive therapy, kidney failure, body mass index (BMI), arterial hypertension, and diabetes mellitus.

RESULTS

Possible adverse events of statins were suffered by 60 patients, all of them men. The causal role of statins was confirmed in 41 (12.2% of all 336): hepatotoxicity was suffered by 13, high CK without muscle ache or weakness by 18, rhabdomyolysis by 5, myalgia by 3, and other effects by 2. The incidence of confirmed statin-related complications was higher among patients with BMI >29 kg/m(2) than among those with lower BMI (P = .055). None of the patients with confirmed statin-related complications needed dialysis, none died, and permanent suspension of statin treatment was only necessary in 13 cases (3.9% of the 336).

CONCLUSIONS

Some 10% to 20% of HT patients appear to suffer adverse side effects of initial statin therapy. However, early detection of such effects through diligent clinical and analytical monitoring allows the therapy to be modified in time to minimize the appearance of severe complications. In only a minority of cases permanent suspension of statin therapy is necessary.