Frequency of hypercholesterolemia after cardiac transplantation

Effect of cyclosporin on plasma lipoproteins in bone marrow transplantation patients

The effects of cyclosporin and prednisone on plasma lipid and lipoprotein levels were studied in 20 allogeneic bone-marrow transplantation patients receiving cyclosporin plus prednisone therapy, and in 14 allogeneic patients treated only with cyclosporin during 100 days. Eighteen autologous bone-marrow patients not requiring cyclosporin were used as a control group. Patients were studied 5 days prior to transplantation, and on days 30, 60, and 100 after transplantation. To determine the reversibility of the changes, lipid parameters were analyzed 30 days after completion of the treatment. Nutritional supplementation, conditioning regimens, and concomitant medications were not significantly different between groups. Furthermore, no significant differences in age, weight, lipid, or lipoprotein levels were found at baseline. Our results indicate that cyclosporin therapy induces a reversible increase of plasma cholesterol, LDL-cholesterol, triglycerides, VLDL-triglycerides, and apolipoprotein B and a decrease of HDL-cholesterol, HDL2-cholesterol, and apolipoprotein A-I. The addition of prednisone to cyclosporin therapy induces a higher increase in plasma cholesterol mainly due to an increase in HDL-cholesterol. Total cholesterol/HDL-cholesterol ratio increased significantly in patients treated only with cyclosporin. No differences were found in this ratio in patients treated with prednisone compared to those submitted to autologous bone-marrow transplantation. Lipid changes observed in this study were reversible 30 days after cessation of cyclosporin treatment.

Effect of cyclosporin on plasma lipoprotein lipase activity in rats

The effects of cyclosporin on plasma lipoproteins and lipoprotein lipase (LPL) activity were studied in rats treated with different doses of the drug for periods ranging between 7 and 30 days. The treatment with cyclosporin resulted in an increase in plasma triglycerides and non-HDL-cholesterol, and a dose and time-dependent decrease of LPL activity and HDL-cholesterol, mainly because of a fall in the HDL2-cholesterol subfraction. The decrease of LPL activity was positively correlated (p < 0.01) with plasma HDL-cholesterol and HDL2-cholesterol and negatively with plasma triglycerides and non-HDL-cholesterol (p < 0.01). Our results indicate that the decrease in plasma LPL activity may be responsible for the increase in plasma triglycerides and the decrease in plasma HDL-cholesterol found in rats under cyclosporin treatment.

Impairment of coronary flow reserve in orthotopic cardiac transplant recipients with minor coronary occlusive disease

OBJECTIVE

Coronary occlusive disease is the major long-term complication after cardiac transplantation. The relation between minor angiographic abnormalities and myocardial perfusion has not been previously assessed in a large number of cardiac transplant patients.

DESIGN

Prospective study. Coronary flow reserve was measured with an intracoronary Doppler flow probe in the proximal left anterior descending coronary artery in each patient. A dose of intracoronary papaverine producing maximal vasodilation was then administered.

SETTING

A regional cardiothoracic centre and a supraregional transplant unit.

PATIENTS

Seven patients with chest pain but normal coronary anatomy (controls), and 61 cardiac transplant patients between three months and 10 years after operation (median 4.5 years). Twenty one cardiac transplant patients had angiographic evidence of minor coronary occlusive disease (mean (SD) percentage stenosis diameter 23% (6%)) in a primary or secondary coronary vessel (group 1), with 12 of these in the left anterior descending coronary artery (stenosis diameter (mean (SD) 24% (8%)). The remaining 40 transplant patients had normal coronary angiograms (group 2).

MAIN OUTCOME MEASURE

Coronary flow reserve was defined as the ratio of the peak flow velocity after papaverine to the resting flow velocity.

RESULTS

Group 1 patients had a noticeably impaired coronary flow reserve (2.6 (1.1)) compared with control patients (3.9 (0.4), p = 0.05) and, after adjusting for year after operation, compared with group 2 patients (3.8 (1.0), p < 0.001). No other variables were associated with a reduction in coronary flow reserve. Mean resting flow velocity was similar in all three groups (controls, 7.4 (4.6) cm/s; group 1, 7.5 (5.9) cm/s; and group 2, 7.3 (3.9) cm/s). Mean peak flow velocity response to papaverine was reduced in group 1 patients (18.1 (13.5) cm/s) relative to group 2 patients (27.5 (15.4) cm/s, p = 0.05) but not controls (28.4 (15.1) cm/s, p = 0.1).

CONCLUSIONS

Coronary flow reserve and the peak flow response to the coronary vascular smooth muscle relaxant papaverine are impaired in cardiac transplant patients with minor coronary occlusive disease. This disturbance of cardiac microvascular function may contribute to the late morbidity and mortality seen in cardiac transplant patients with coronary occlusive disease.

Coronary occlusive disease and late graft failure after cardiac transplantation

OBJECTIVE

Coronary occlusive disease is the main cause of late mortality after cardiac transplantation. It has both similarities and differences compared with conventional atherosclerotic coronary disease. The pathophysiology of late graft failure from coronary occlusive disease is unclear at present. We reviewed the experience of this disorder in our cardiac transplant programme.

DESIGN

A retrospective analysis of angiographic and pathological data.

SETTING

A regional cardiothoracic centre and transplant unit.

PATIENTS

Of a population of 383 orthotopic cardiac transplant recipients operated upon between January 1979 and June 1990, 447 coronary angiograms were available for review in 193 patients. Thirteen of a possible 18 results of post mortem examinations from patients dying from coronary occlusive disease were available.

MAIN OUTCOME MEASURE

Coronary occlusive disease was defined as any evidence of disease on coronary angiography. Post mortem examinations were performed with standard techniques.

RESULTS

The angiographic prevalence of coronary occlusive disease was 3% (1/32 patients) and 40% (19/47 patients) at one and five years respectively. Twenty six grafts failed due to coronary occlusive disease compared with 132 graft failures from all causes during this period. Acute thrombosis was present in a large vessel in seven of 13 fatal cases undergoing necropsy (54%). Noticeable large vessel involvement with disease in smaller distal vessels was present in four patients (31%). The remaining two patients (15%) had small vessel disease alone. Twelve of the 13 patients had significant cardiomegaly (cardiac weight > or = 400 g) with a mean weight of 510 (range 370-740) g.

CONCLUSION

Coronary occlusive disease is the main late complication after cardiac transplantation. A combination of coronary thrombosis, ischaemia from stenoses of large and small coronary vessels, and cardiomegaly contribute to the graft failure of these patients.

Factors influencing the development of hypercholesterolemia after cardiac transplantation

Although hypercholesterolemia is a frequent complication in cardiac transplant recipients, the exact mechanisms contributing to its development are not known. Cholesterol levels in 151 thoracic transplant patients treated with cyclosporine, azathioprine and prednisone were retrospectively examined to evaluate the factors influencing the heterogeneity of changes after the first year after transplantation in patients on a standard 3-drug immunosuppression regimen. Three groups were compared including ischemic heart transplant (n = 72), nonischemic heart transplant (n = 64) and heart-lung/lung transplant (n = 15) recipients. After the first year, 64 patients (43%) developed consistent hypercholesterolemia (greater than 240 mg/dl) for which pharmacologic treatment was initiated. Forty-eight patients (67%) in the ischemic heart transplant group required treatment, significantly (p less than 0.001) greater than both the nonischemic (n = 14; 22%) and heart-lung/lung transplant (n = 2; 13%) group. Univariate and forward stepwise multivariate regression analysis identified 4 factors that were all significantly and independently correlated with follow-up cholesterol including prednisone dose (p less than 0.001), baseline cholesterol (p less than 0.001), glucose (p less than 0.001) and weight gain (p less than 0.01). Changes in triglycerides in the 3 groups of patients were similar to changes in cholesterol. Furthermore, the increase in cholesterol in patients requiring treatment was primarily due to an increase in low-density lipoprotein cholesterol. These data demonstrate that hypercholesterolemia is common in heart transplant recipients treated with standard 3-drug immunosuppression and generally develops within the first 2 years after transplantation. However, this complication is not uniform and appears to be most strongly related to previous coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Liver transplantation modifies serum cholestanol, cholesterol precursor and plant sterol levels

Proportions of cholesterol precursors (squalene, delta 8-cholestenol, desmosterol and lathosterol), plant sterols (campesterol and sitosterol) and cholestanol to cholesterol in serum were measured before and serially after liver transplantation in eight patients with primary biliary cirrhosis (PBC) and three with acute liver necrosis. The preoperative proportions of cholestanol were 12 and 3-times higher in the PBC and necrosis groups, respectively, than in a control group of 27 individuals, while those of lathosterol were low in both groups and the campesterol/sitosterol ratio in the PBC group. During the operation the proportions of cholestanol fell sharply and those of lathosterol rose especially in the PBC group. During the postoperative follow-up of 5 weeks the proportions of the non-cholesterol sterols were markedly improved especially in the necrosis group yet those of cholestanol remained high and the campesterol/sitosterol ratios low, particularly in the PBC group. The proportions of lathosterol increased gradually almost to the control limits within the postoperative 5-week period, whereas those of desmosterol decreased. The non-cholesterol sterol values were not related to acute rejections, while significant correlations of cholestanol to liver function tests was found especially at the end of the follow-up.

Hyperlipidemia after heart transplantation: report of a 6-year experience, with treatment recommendations

Mean plasma lipid values in 100 patients who survived greater than 3 months after heart transplantation increased significantly at 3 months over pretransplantation values: total cholesterol from 168 +/- 7 to 234 +/- 7 mg/dl, low density lipoprotein (LDL) cholesterol from 111 +/- 6 to 148 +/- 6 mg/dl, high density lipoprotein (HDL) cholesterol from 34 +/- 1 to 47 +/- 1 mg/dl and triglycerides from 107 +/- 6 to 195 +/- 10 mg/dl. There were no significant increases after this time. The LDL cholesterol values reamined greater than or equal to 130 mg/dl in 64% of patients and triglyceride values remained greater than or equal to 200 mg/dl in 41% of patients 6 months after postoperative dietary instructions. Beginning in 1985, select patients whose total cholesterol values remained greater than 300 mg/dl despite 6 months of dietary intervention were treated with lovastatin given alone in a high dose (40 to 80 mg/day) or in combination with another hypolipidemic agent. Four of the five patients so treated developed rhabdomyolysis; two of the four had acute renal failure. Beginning in 1988, a second protocol--lovastatin at 20 mg/day as monotherapy--was used in patients who despite dietary intervention had total cholesterol greater than 240 mg/dl (mean follow-up 13 months). In the 15 patients so treated, mean total cholesterol decreased from 299 +/- 10 mg/dl before treatment with lovastatin to 235 +/- 9 mg/dl during treatment (21% reduction, p less than 0.001) and mean LDL cholesterol was reduced from a baseline value of 190 +/- 10 to 132 +/- 12 mg/dl during treatment (31% reduction, p less than 0.001). In this study, lovastatin at a dose of less than or equal to 20 mg/day as monotherapy was a well tolerated, effective treatment for hyperlipidemia after heart transplantation. It did not result in rhabdomyolysis and required no alteration in immunosuppressive therapy. However, the dose should not exceed 20 mg/day and combination therapy with either gemfibrozil or nicotinic acid should be avoided, even if the target LDL cholesterol value is not reached.

Pharmacokinetics of cyclosporine in hyperlipidaemic long-term survivors of heart transplantation. Lack of interaction with the lipid-lowering agent, fenofibrate

Cyclosporine (Cy) binds to lipoproteins in plasma. In order to test if its pharmacokinetics would be modified when efficient lipid-lowering treatment is introduced, a study has been done of Cy pharmacokinetics and any interaction with the lipid-lowering agent fenofibrate in hyperlipidaemic long-term, survivors of heart transplantation. Fenofibrate 200 mg once daily significantly reduced blood lipids (cholesterol 6.5 vs 7.7 mmol/l; apoprotein B 1.2 vs 1.6 g/l) but did not modify mean whole blood Cy trough levels (113 before fenofibrate vs 103 ng.ml-1), Cmax (812 ng.ml-1 by RIA and 757 ng.ml-1 by HPLC before fenofibrate versus 865 and 741 respectively, during fenofibrate); tmax (1.6 and 1.7 h before fenofibrate versus 1.4 and 1.4 h respectively), and t1/2 (13.9 and 11.1 h versus 9.5 and 10.7 h). The only adverse effect was an increase in creatinine (157 vs 145 mmol/l). Further studies are needed to investigate the mechanism of Cy-fenofibrate nephrotoxicity and to evaluate the long-term efficiency and safety of fenofibrate after heart transplantation.

Lipoprotein(a) and apolipoprotein changes after cardiac transplantation

Although lipoprotein changes after cardiac transplantation have been documented, the effects of transplantation and subsequent immunosuppressive therapy (particularly the combination of prednisone, azathioprine and cyclosporine) on apolipoprotein levels and lipoprotein(a) have not been reported. Fasting cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, apolipoprotein A-1 and B-100 and lipoprotein(a) were evaluated in 69 consecutive patients during the waiting period before cardiac transplantation. There were 28 deaths before donor organ identification and 41 patients received a cardiac allograft. The lipoprotein levels of transplant recipients were again assayed 3 months postoperatively. Mean (+/- SEM) values increased for total plasma cholesterol (from 180 +/- 8 to 228 +/- 8 mg/dl, p less than or equal to 0.001), triglycerides (from 126 +/- 11 to 207 +/- 14 mg/dl; p less than or equal to 0.001), HDL cholesterol (from 39 +/- 2 to 49 +/- 3 mg/dl; p less than or equal to 0.002) and LDL cholesterol (from 119 +/- 7 to 138 +/- 7 mg/dl; p less than 0.02). Apolipoprotein A-1 and B-100 also increased, but lipoprotein(a) decreased from 11.7 +/- 1.7 to 6.8 +/- 1.1 mg/dl; p less than or equal to 0.0001) after transplantation. Although total cholesterol, triglycerides, LDL cholesterol, apolipoprotein A-1 and B-100 increased dramatically after cardiac transplantation, so did HDL cholesterol, thereby keeping the LDL/HDL cholesterol ratio constant. The surprising decrease in lipoprotein(a) after cardiac transplantation suggests that metabolism of lipoprotein(a) is independent of LDL cholesterol and that immunosuppressive drugs either decrease the synthesis or increase catabolism of lipoprotein(a).

Aortic distensibility in patients with isolated hypercholesterolaemia, coronary artery disease, or cardiac transplant

The stiffness of the thoracic aorta can be assessed non-invasively. If aortic stiffness can be shown to be related to coronary heart disease, perhaps it can be used to identify which patients with hypercholesterolaemia are most likely to have atheromatous changes and thus to be selected for intensive cholesterol-lowering treatment. Hence the distensibility of the transverse aortic arch was measured by echocardiography of the aortic arch in four groups of patients--symptom-free patients with normal serum cholesterol; symptom-free patients with raised serum cholesterol; patients with coronary heart disease (all with raised serum cholesterol), and post-heart-transplant patients. In all groups distensibility fell with age. The regression slope was steeper (p less than 0.05) for patients with known coronary disease than for either of the disease-free groups, and among cardiac transplant recipients there was also a segregation of distensibility values between those with and without atheroma in their native hearts. The results indicate that aortic distensibility might be an indicator of coronary heart disease and that it might be useful in identifying which symptom-free subjects with modest hypercholesterolaemia should be treated aggressively.

Dose response of fish oil versus safflower oil on graft arteriosclerosis in rabbit heterotopic cardiac allografts

With the advent of cyclosporin A, accelerated coronary arteriosclerosis has become the major impediment to the long-term survival of heart transplant recipients. Due to epidemiologic reports suggesting a salutary effect of fish oil, the dose response of fish oil on graft coronary arteriosclerosis in a rabbit heterotopic cardiac allograft model was assessed using safflower oil as a caloric control. Seven groups of New Zealand White rabbits (n = 10/group) received heterotropic heart transplants from Dutch-Belted donors and were immunosuppressed with low-dose cyclosporin A (7.5 mg/kg/day). Group 1 animals were fed a normal diet and served as control. Group 2, 3, and 4 animals received a daily supplement of low- (0.25 mL/kg/day), medium- (0.75 mL/kg/day), and high- (1.5 mL/kg/day) dose fish oil (116 mg n-3 polyunsaturated fatty acid/mL), respectively. Group 5, 6, and 7 animals were supplemented with equivalent dose of safflower oil (i.e., 0.25, 0.75, and 1.5 mL/kg/day). Oil-supplemented rabbits were pretreated for 3 weeks before transplantation and maintained on the same diet for 6 weeks after operation. The extent of graft coronary arteriosclerosis was quantified using computer-assisted, morphometric planimetry. When the animals were killed, cyclosporin A was associated with elevated plasma total cholesterol and triglyceride levels in the control group. While safflower oil prevented the increase in plasma lipids at all dosages, fish oil ameliorated the cyclosporin-induced increase in total cholesterol only with high doses. Compared to control animals, there was a trend for more graft vessel disease with increasing fish oil dose, as assessed by mean luminal occlusion and intimal thickness. A steeper trend was observed for increasing doses of safflower oil; compared to the high-dose safflower oil group, animals supplemented with low-dose safflower oil had less mean luminal occlusion (16.3% +/- 5.9% versus 41.4% +/- 7.6%, p less than 0.017) and intimal thickness (7.9 +/- 1.9 microns versus 34.0 +/- 13.0 microns, analysis of variance: p = 0.054). Low-dose safflower oil also had a slight, but nonsignificant, beneficial effect on graft vessel disease when compared to control rabbits. The same trends were observed in the degree of histologic rejection (0 = none to 3 = severe) in fish oil- and safflower oil-treated animals. Rejection score correlated weakly but significantly (p = 0.0001) with mean luminal occlusion (r = 0.52) and intimal thickness (r = 0.46). Therefore allograft coronary disease in this model appeared to exhibit an unfavorable, direct-dose response to fish oil and safflower oil, independent of effects on plasma lipids.(ABSTRACT TRUNCATED AT 400 WORDS)

The pathophysiology of Sandimmune (cyclosporine) in man and animals

Part II: The side-effects of Sandimmune that have also been observed clinically include hepatic dysfunction, glucose intolerance, thrombo-embolic complications and nervous system disorders. To determine the cause and significance of such effects, the actions of Sandimmune on the liver, the pancreas, on hematostasis and the nervous system were examined. Comparisons were made between animal and human data obtained in vivo and in vitro, and the clinical setting under which the side-effects occur was analyzed. The actions of Sandimmune on the liver seem to reflect mostly a cholestasis with a small depression in protein synthesis and a mild disturbance in lipid metabolism of uncertain origin. The action of Sandimmune on the pancreas suggests insulin resistance and possibly a secretory disturbance, with no evidence for depressed insulin synthesis, except in animals at high doses. Sandimmune does not seem to promote thromboembolism in man, although fibrinolysis may be depressed and platelet aggregation can be enhanced. The effects of Sandimmune on the nervous system are unclear, for tremor is common but of uncertain origin, whereas seizures and encephalopathy are rare and invariably associated with other risk factors.

Serial evaluation of lipid profiles and risk factors for development of hyperlipidemia after cardiac transplantation

To determine the prevalence, time course and factors responsible for hyperlipidemia after heart transplantation, 83 consecutive 1-year survivors were studied. By 1 year, 83% of patients had serum total cholesterol levels greater than 5.2 mmol/liter (200 mg/dl) and 28% of the patients had serum total cholesterol higher than the age- and sex-matched ninety-fifth percentile. At the end of 1-year follow-up, serum total cholesterol correlated with the recipient age (p less than 0.0001), the preoperative cholesterol level (p less than 0.001), the actual dose of maintenance prednisone at 1 year (p less than 0.02) and the cumulative 1-year steroid dose (p less than 0.03). Similarly, the serum triglyceride level at 1 year correlated with the pretransplant level of serum triglycerides (p less than 0.0001), recipient age (p less than 0.03) and cumulative 1-year steroid dose (p less than 0.03). Patients with a pretransplant diagnosis of coronary artery disease had a significantly higher level of serum total cholesterol and triglyceride levels at 1 year (p less than 0.02 and p less than 0.03, respectively). Heart transplant recipients with body mass index greater than or equal to 25 kg/m2 also presented with significantly elevated serum total cholesterol and triglyceride levels at 1 year compared with nonobese patients (p less than 0.01 and p less than 0.002, respectively). Hyperlipidemia occurs frequently and is detected within the first month after heart transplantation. Optimal management of this problem requires further study.

Lovastatin therapy for hypercholesterolemia in cardiac transplant recipients

Hypercholesterolemia (type II hyperlipidemia) after cardiac transplantation is common and may play a role in the accelerated rate of coronary atherosclerosis seen following the procedure. However, conventional cholesterol-lowering drugs are either ineffective or contraindicated for use in transplant recipients. The presence of type II hyperlipidemia was identified in 11 cardiac transplant recipients during a mean follow-up period of 15 months (range 3 to 41) after transplantation. Lovastatin, at an initial dosage of 20 mg/day, was administered for a period of 1 year. The maximal dosage of lovastatin was 60 mg/day. All patients received maintenance dosages of immunosuppressive agents, including cyclosporine-A, prednisone and, in some instances, azathioprine. Lipid profiles, hepatic transaminases, serum creatinine, creatine kinase and cyclosporine-A serum trough levels were measured quarterly. Total cholesterol decreased by 27% (354 +/- 50 vs 258 +/- 36 mg/dl, p less than 0.01) after 3 months and remained stable thereafter. Similarly, low density lipoprotein cholesterol decreased by 34% (221 +/- 51 vs 146 +/- 40 mg/dl, p less than 0.01) after 3 months and remained constant. Triglycerides, high density lipoprotein, hepatic transaminases, creatinine, creatine kinase and trough cyclosporine-A levels remained stable during the 1-year follow-up period. Lovastatin was uniformly well tolerated in this study group. When given in modest dosages, lovastatin appears to be a safe, effective and well-tolerated therapy for hypercholesterolemia in cardiac transplant recipients.