Statins after cardiac transplantation: which statin, what dose, and how low should we go?

The effect of statins on cardiac allograft survival

PURPOSE

In addition to having a lipid-lowering effect, statins also have an anti-inflammatory effect that may reduce allograft dysfunction by preventing cardiac allograft vasculopathy (CAV) and play an immunomodulatory role. We studied the effect of statins on cardiac allograft survival at the National Taiwan University Hospital (NTUH).

MATERIALS AND METHODS

We retrospectively reviewed the patients undergoing heart transplantation at NTUH in the last 6 years. After transplantation, all patients received biochemical monitoring every month and echocardiographic examination regularly at NTUH. Protocol biopsy was performed in all except 18 pediatric patients. All patients received immunosuppressants, including tacrolimus or cyclosporine, everolimus or mycophenolate acid, and prednisolone. They were divided into statin and nonstatin groups according to whether or not a statin was taken.

RESULTS

At NTUH, from 2007 to 2012, 168 heart transplantations were performed. The ages of the patients ranged from 6 to 74 years old with male predominance. The etiology was mainly dilated cardiomyopathy (52.4%) and ischemic cardiomyopathy (39.3%), including 7 retransplantations from severe CAV with heart failure. Twenty-three patients (17%) suffered from acute rejection. The overall 1-year actuarial survival rate was 86% ± 2% and the 5-year survival rate was 79% ± 3%. Seventy-eight patients (57.4%) took statins and the statin group has a better 5-year survival rate and freedom from cardiac death survival rate (P < .01).

CONCLUSION

Our study showed that the use of statins after transplantation was associated with better survival.

Cardiac allograft vasculopathy: The achilles’ heel of long-term survival after cardiac transplantation

Over the past 40 years, cardiac transplantation has evolved as the single best long-term option for eligible candidates with end-stage heart failure. Approximately 2000 transplants are performed annually in the United States, and with the institution of calcineurin-based immunotherapy, surveillance biopsies, and programmatic-based patient care, life expectancy at 1 and 12 years is 85% and 50%, respectively. Cardiac allograft vasculopathy (CAV) is the number one cause of death after the first year of transplantation. The incidence of CAV remains as high as 50% at 5 years, with life expectancy significantly abbreviated once it is recognized. Although current immunotherapy has reduced the likelihood of cellular rejection, it has not impacted CAV substantially. Better treatment of established risk factors and the advent of newer antiproliferative immunotherapy may hold promise in treating CAV. However, future therapies must address the multitude of mechanisms underlying CAV. This manuscript reviews the pathophysiology, clinical manifestations, screening, and diagnostic strategies for cardiac allograft vasculopathy while emphasizing current treatment paradigms designed to stave off or retard the progression of CAV.

Safety and Efficacy of Rosuvastatin Therapy for the Prevention of Hyperlipidemia in Adult Cardiac Transplant Recipients

BACKGROUND

Hyperlipidemia after orthotopic heart transplantation (OHT) is associated with immunosuppression. Many OHT patients have increased lipid levels above published guidelines despite treatment with high doses of statins. Treatment with rosuvastatin (ROS) in OHT patients has not yet been evaluated. Therefore, we assessed its efficacy and safety in an OHT population.

METHODS

Twenty-one OHT recipients, median age 66 years, whose lipid levels were sub-optimal on the highest tolerated doses of statins, received ROS in addition to standard immunosuppression. Total cholesterol (TC), low-density lipoprotein (LDL-C) and high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), liver transaminases (AST) and creatinine kinase (CK) were measured before and during treatment with ROS.

RESULTS

After 6 weeks on an average ROS dose of 10 mg/day, a TC:HDL-C ratio of <4 was reached in 76% of patients, and 70% of patients reached an LDL-C level of <2.5 mmol/liter (100 mg/dl). TC decreased to <5.2 mmol/liter (200 mg/dl) in 80% of patients and TG decreased to <2 mmol/liter (175 mg/dl) in 61% of patients. Except for the HDL-C increase, all changes were statistically significant. The decrease in the median TC:HDL-C ratio between baseline and 6 weeks was also statistically significant (p = 0.001). There were no significant changes in CK or AST levels, and no clinical evidence of myositis. One patient developed myalgia and 2 were withdrawn from the study because of mild elevation of CK (<3-fold upper limit of normal [ULN]).

CONCLUSIONS

In the setting of tertiary referral centers, ROS appears to be safe and effective in lowering LDL-C in OHT recipients in whom treatment with other statins failed to achieve target LDL-C. No evidence of liver or muscle dysfunction was noted. Long-term studies are needed to ascertain the effect of ROS therapy on incidence of coronary artery disease (CAD) in this population.

Metaanalysis of statins and survival in de novo cardiac transplantation

BACKGROUND

The use of HMG CoA reductase inhibitors (statins) after cardiac transplantation has been suggested to decrease the incidence of severe rejection and improve survival. Individual investigations that have led to this suggestion are randomized (but not placebo-controlled) studies, including small patient numbers that have (and thus underpowered) and enrolling heterogeneous subjects (including retransplant recipients). The purpose of this pooled analysis was to quantify the benefit of statins on survival in de novo cardiac transplant recipients.

METHODS

Medline (1966 to 2003) was queried using the keywords statin, HMG CoA reductase inhibitors, cardiac transplantation, transplant, cholesterol, atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin. In addition, we searched the cited literature and previously published systematic reviews. Of 36 articles retrieved, 3 randomized controlled studies met our population inclusion criteria; namely age >18 years, de novo heart transplant recipients, statin therapy within 3 months, and > or = 1-year follow-up. Pooled data were metaanalyzed by Mantel-Haenszel tests using a random effects model that included tests for heterogeneity.

RESULTS

The three pooled studies included 246 patients (statin, n = 129; no statin, n = 117) and 27 events (11%). The pooled analysis demonstrated a significant reduction in mortality with statin use (RR 0.31; 95% CI 0.13 to 0.7; P = .006) without significant heterogeneity (P = .7) among the studies. Two of the three studies reported allograft rejection with hemodynamic compromise. The pooled analysis demonstrated a significant benefit on this endpoint (RR 0.22, 95% CI 0.08 to 0.63; P = .004).

CONCLUSION

This meta-analysis demonstrates that statin therapy decreases rejection episodes with hemodynamic consequences and improves 1-year heart transplant survival.

Statin inhibition of Fc receptor-mediated phagocytosis by macrophages is modulated by cell activation and cholesterol

OBJECTIVES

An inflammatory response to altered lipoproteins that accumulate in the arterial wall is a major component of the pathogenesis of atherosclerosis. Statins reduce plasma levels of low-density lipoprotein (LDL) and are effective treatments for atherosclerosis. It is hypothesized that they also modulate inflammation. The aim of this study was to examine whether lovastatin inhibits macrophage inflammatory processes and clarify its mechanism of action.

METHODS AND RESULTS

We examined the effects of statins on phagocytosis of antibody-coated red blood cells by cultured human monocytes and mouse peritoneal macrophages. Lovastatin, simvastatin, and zaragozic acid, a squalene synthase inhibitor, blocked Fc receptor-mediated phagocytosis by cultured human monocytes and mouse peritoneal macrophages. The inhibitory effect of lovastatin on Fc receptor-mediated phagocytosis was prevented completely by addition of mevalonate, farnesyl pyrophosphate, LDL, or cholesterol to the culture medium. The inhibitory effect of zaragozic acid was reversed by addition of LDL, but not by the addition of geranylgeranyl pyrophosphate, to the medium. In addition, the effect of lovastatin on phagocytosis is a function of cell activation because treatment of cells with tumor necrosis factor-alpha or lipopolysaccharide prevented inhibition of phagocytosis by lovastatin.

CONCLUSIONS

The inhibition of Fc receptor-mediated phagocytosis of lovastatin is related to its effect on cholesterol biosynthesis rather than its effect on the formation of isoprenoids.

Treatment of hyperlipidemia in cardiac transplant recipients

Of the 60,000 patients receiving heart transplants between 1982 and 2001, approximately 12,000 are currently alive. The high incidence of hyperlipidemia and coronary disease (also known as accelerated graft atherosclerosis, or AGA) in these patients warrants early prophylaxis soon after transplantation with 3-hydroxy-3-methylglutaryl (HMG) Co-A reductase inhibitors (statins). Immunosuppressive agents such as prednisone, cyclosporine, mycophenylate mofetil, and sirolimus are associated with hyperlipidemia. Statins, in addition to lowering cholesterol levels, also benefit cardiac transplant recipients via effects on the immune system and endothelial function. Recent data have demonstrated that statins decrease AGA and mortality rates. Furthermore, greater benefits are seen when statins are started early. The 2 statins shown to decrease mortality in patients after cardiac transplantation are pravastatin and simvastatin, which differ in their metabolism (pravastatin is the only statin with non-cytochrome metabolism) and lipophilicity (pravastatin is less lipophilic). Although the benefit of simvastatin has been shown to extend to 8 years after transplantation, increased adverse effects in other studies with higher doses of simvastatin have resulted in new prescribing recommendations, which state that the dose of simvastatin should probably not exceed 10 mg with cyclosporine or gemfibrozil and 20 mg with amiodarone or verapamil. The evidence for potential benefits, interactions, and adverse effects of other potential lipid-lowering drugs for this patient population, such as fibrates, niacin, fish oil, cholestyramine, and ezetimibe, are also discussed. A summary algorithm is proposed, including approaches to patients with statin-associated musculoskeletal symptoms and patients with inadequate results after initial statin therapy.

Efficacy and safety of fluvastatin therapy for hypercholesterolemia after heart transplantation

BACKGROUND

Hypercholesterolemia is frequent after heart transplantation. Statins can reduce cholesterol levels but their use in heart transplant patients is complicated by pharmacokinetic interactions with cyclosporin and the risk of serious adverse effects including rhabdomyolysis. Fluvastatin has been used safely to treat hypercholesterolemia in renal transplant patients but there are few data relating to its use after heart transplantation. Therefore, we conducted a randomised blinded placebo controlled trial.

METHODS AND RESULTS

Seventy-nine patients, 3 months to 12 years after heart transplantation with a low density lipoprotein (LDL) cholesterol between 3.5 and 8.0 mmol/l were randomly assigned, in a 2:1 ratio, to receive either fluvastatin 40 mg od (n=52) or matching placebo (n=27). Changes in total cholesterol (TC) in the fluvastatin and placebo groups were -17.0% and +4.5%, respectively, (p<0.001); the corresponding changes in LDL were -20.5% and +4.8% (P<0.001) and in triglycerides -14.5% and +7.1% (p=0.012) at the end of the 1-year study period. Withdrawals were more frequent in the fluvastatin group (23% vs. 11% p=0.24). Two deaths occurred during the study (the rate expected from International Society of Heart Lung Transplantation registry) and appeared to be unrelated to the study medication. There were no episodes of rhabdomyolysis or other serious drug-related side effects.

CONCLUSIONS

Fluvastatin (40 mg/day) was both an effective and a safe treatment for hypercholesterolemia in patients who had undergone heart transplantation more than 3 months previously.

Coronary artery vasculopathy in pediatric cardiac transplant patients: the therapeutic potential of immunomodulators

The single largest cause of late graft loss in pediatric cardiac transplantation is transplant coronary artery vasculopathy (CAV). The mechanism of CAV remains unknown; it appears to have both immune and non-immune causes. The final common pathway of these mechanisms is endothelial activation, a prothrombotic environment, and endothelial damage with subsequent diffuse intimal proliferation. The disease process has largely been thought to be progressive and unresponsive to treatment. Re-transplantation has been advocated as the only definitive treatment. The appropriate management is largely unknown; intervention or surgical management has had limited utility, while medical management appears to have the most promise. Improvement in outcome can be achieved by optimizing non-immune factors and aggressive management of the immune mechanisms. Long-term survival of transplant patients after diagnosis with CAV is now being reported.

Comparative beneficial effects of simvastatin and pravastatin on cardiac allograft rejection and survival

OBJECTIVES

We sought to evaluate the relative effects of low doses of pravastatin (20 mg/day) and simvastatin (10 mg/day) on indices of cardiac allograft rejection. We further examined the relative efficacy and safety of these two drugs on lipid-lowering in heart transplantation.

BACKGROUND

The immunomodulatory effects of hydroxy methyl glutaryl-coenzyme A reductase inhibitors have been increasingly recognized. Previous studies have demonstrated an ameliorative influence of pravastatin on hemodynamically compromising rejection after heart transplantation. A recent observational trial suggested that simvastatin 20 mg/day was associated with trends to lower survival and more adverse effects than pravastatin 40 mg/day.

METHODS

In a 12-month prospective, open-label study, 50 heart transplant recipients received either open-label pravastatin 20 mg daily (n = 24) or simvastatin 10 mg daily (n = 26) within four weeks of transplantation. Indices of allograft rejection including treated rejection, rejection with hemodynamic compromise, noncellular rejection, and mean one-year biopsy score were compared between the two cohorts, as well as with a statin-naive control population (n = 37). Lipid levels, safety, and post-transplant outcomes were also assessed as secondary end points.

RESULTS

We found no significant differences in any allograft rejection parameter between the two groups. However, total low-density lipoprotein (LDL), but not high-density lipoprotein cholesterol or triglycerides, were lower in the simvastatin arm (-23% vs. -11%, p = 0.02). No cases of rhabdomyolysis or myositis occurred in either group. Survival at one year was similar in both treatment groups (91% for patients on pravastatin and 92% for patients on simvastatin). Both groups had better survival compared with the statin-naive control group (80%, p = 0.04).

CONCLUSIONS

Simvastatin (10 mg/day) and pravastatin (20 mg/day) are associated with similar beneficial effects on cardiac allograft rejection and one-year survival. At these doses, simvastatin decreases LDL cholesterol more so than pravastatin with no increase in adverse effects in heart transplantation.

[Utility of pravastin in cardiac transplant dyslipidemia]

Patients undergoing cardiac transplantation are at increased risk of dyslipidemia (60% to 80%). Lipid-lowering treatment in these patients should be aggressive given the known role of dyslipidemia in chronic transplant rejection. The objective of this study was to evaluate the efficacy and safety of pravastatina therapy and its effect upon cyclosporine levels in a population of dyslipidemic cardiac transplant patients.A total of 20 cardiac transplant patients were enrolled in this 39-week length prospective observational study. Patients had serum cholesterol levels exceeding 200 mg/dl, and received pravastatin therapy at the adequate dose to obtain an optimal lipid profile without significant adverse effects. Pravastatin, at a mean dose of 50 18 mg/day, produced a significant reduction in total cholesterol levels (from 291 32 to 203 25 mg/dl, p < 0.05), LDL cholesterol (from 187 34 to 102 15 mg/dl, p < 0.05) and an increase in HDL-cholesterol levels (from 48 16 to 55 14, p < 0.05). A slight asymptomatic increase in CPK levels was observed but no differences in cyclosporine levels. Pravastatin has shown to be an effective and safe therapy in dyslipidemic cardiac transplant patients.

Neurologic complications of transplantation

BACKGROUND

Organ transplantation is one of the most dynamic fields in medicine and has evolved into a life-saving option for thousands of patients with previously fatal conditions. The posttransplantation clinical course is frequently associated with neurologic complications that are usually related to pretransplant morbidity, the surgical procedure of transplantation, immunosuppression, and opportunistic infection.

REVIEW SUMMARY

Neurologic complications of organ transplantation may be divided into complications common to all types of allografts and complications that are specific for a particular type of organ transplantation. The most common complications include seizures, opportunistic central nervous system (CNS) infection, metabolic encephalopathy, stroke, intracranial hemorrhage, and drug-related adverse events. Opportunistic CNS infection may have a subtle presentation and should not be overlooked, as the consequences of delayed treatment may be grave. Neurotoxicity of immunosuppressive agents is also a frequent cause of neurologic complications and may occur in the setting of normal serum drug levels. The clinical course of transplant patients is frequently complex, requiring close cooperation between the transplant team and specialty consultants. Prolonged survival of transplant patients will shift the focus of neurologic complications from acute, perioperative to chronic complications of immunosuppression.

CONCLUSIONS

Neurologic complications of organ transplantation are commonly related to opportunistic infection or neurotoxicity of immunosuppressive agents, requiring careful titration of immunosuppression. Timely diagnosis of CNS infection or other causes of neurologic dysfunction may significantly improve recovery and outcome in these patients.

Safety and efficacy of atorvastatin in heart transplant recipients

BACKGROUND

Pravastatin and simvastatin prolong survival and reduce transplant-related coronary vasculopathy, although low-density lipoprotein (LDL) lowering with these agents is only modest. The objective of this study was to assess the safety of moderate dose atorvastatin and its efficacy when prior treatment with another statin had failed to lower LDL to < 100 mg/dl.

METHODS

Data from 185 patients were retrospectively evaluated for adverse events, duration of exposure (person-days), and the mean atorvastatin dose exposure. Changes in lipid parameters, and prednisone and cyclosporine doses were determined.

RESULTS

SAFETY

48 patients received atorvastatin for 24,240 person-days at a mean dose exposure of 21 +/- 10 mg. Rhabdomyolysis, myositis, myalgias, and hepatotoxicity occurred in 0, 2, 2, and 0 patients, respectively. All events occurred at the 10-mg dose, within the first 3 months, and were rapidly reversible with atorvastatin discontinuation.

EFFICACY

Thirty-four patients evaluable for efficacy analyses had a pre-atorvastatin LDL of 145 +/- 38 mg/dl on the following statins: pravastatin (n = 30, 40 +/- 0mg), fluvastatin (n = 3, 33 +/- 12 mg), simvastatin (n = 1, 40 mg). After atorvastatin (21 +/- 9 mg/day) for 133 +/- 67 days, LDL was reduced to 97 +/- 24 mg/dl (relative reduction 31 +/- 20%, p < 0.0001). At the end of the observation period (418 +/- 229 days, atorvastatin final dose 24 +/- 14 mg/day), LDL was further decreased to 88 +/- 23 mg (relative reduction 37 +/- 17%, p < 0.0001).

CONCLUSION

Atorvastatin, when used at moderate doses and with close biochemical and clinical monitoring, appears to be safe and is effective in aggressively lowering LDL in heart transplant recipients when treatment with other statins has failed to achieve LDL goals.

Safety and efficacy of pravastatin therapy for the prevention of hyperlipidemia in pediatric and adolescent cardiac transplant recipients

BACKGROUND

Hyperlipidemia is common after cardiac transplantation and it is a risk factor for post-transplantation coronary artery disease. Immunosuppression with corticosteroids and cyclosporine has been associated with hyperlipidemia. Pravastatin, a HMG-CoA reductase inhibitor, has been shown to be effective and safe for cholesterol reduction in adult heart transplant recipients. To our knowledge the safety and efficacy of pravastatin therapy in pediatric and adolescent heart transplant populations have not been previously analyzed. Therefore, we evaluated lipid profiles, liver transaminases, rejection data, and possible side effects in pediatric and adolescent cardiac transplant recipients treated with pravastatin.

METHODS

The study group consisted of 40 cardiac transplant recipients 10 to 21 years old (mean age 16.9 years). Twenty-two patients received pravastatin in addition to an immunosuppressive regimen of either cyclosporine or tacrolimus, azathioprine or mycophenolate mofetil, and prednisone. Serial determinations of total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein, and triglycerides were available for all pravastatin-treated patients. Pre-treatment lipid values and hepatic transaminases were compared with those measured after therapy with pravastatin. Comparison of pravastatin-induced lipid reduction between groups treated with cyclosporine vs tacrolimus was also made.

RESULTS

Patients receiving pravastatin experienced a mean 32 mg/dl decrease in TC (p < 0.005) and a mean 31 mg/dl decrease in LDL (p < 0.005), regardless of their immunosuppressive regimen. No statistical differences occurred in the magnitude of mean lipid reduction induced by pravastatin between the groups treated with cyclosporine vs tacrolimus. No significant changes in hepatic transaminase levels were noted, and no clinical evidence of pravastatin-induced myositis occurred in any subjects.

CONCLUSION

Pravastatin therapy is effective and safe when used in pediatric and adolescent cardiac transplant recipients. Although the pravastatin-induced reduction in TC and LDL was more pronounced in patients receiving cyclosporine, the reduction was not statistically different from that in the tacrolimus group. No evidence of hepatic dysfunction or rhabdomyolysis in patients treated with pravastatin was noted. Long-term studies are required to evaluate the effect of pravastatin therapy on the incidence of accelerated coronary atherosclerosis in this population.