Transitioning disopyramide to mavacamten in obstructive hypertrophic cardiomyopathy: A case series and clinical guide

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a genetic disorder for which first-line treatments for obstructive HCM (oHCM) include beta-blockers, non-dihydropyridine calcium channel blockers, and disopyramide for refractory cases. Mavacamten, a selective cardiac myosin inhibitor, is indicated for symptomatic oHCM to improve functional capacity and symptoms. Use of disopyramide and mavacamten together is not recommended due to concerns of additive negative inotropic effects. Transitioning from disopyramide to mavacamten may be preferred to avoid adverse effects and frequent administration, however, the best approach for making the transition has not been established.

CASES

We present a series of seven patients with oHCM who transitioned from disopyramide to mavacamten and underwent echocardiograms mandated by a Risk Evaluation and Mitigations Strategies program. Two methods were employed. The first approach, involving washout of disopyramide before starting mavacamten, resulted in worsening of heart failure symptoms in the first two cases. The second approach, involving tapering disopyramide when starting mavacamten, was successfully implemented in the last five cases, with no adverse effects or worsening of systolic dysfunction.

CONCLUSION

Our method of tapering disopyramide when starting mavacamten using a stepwise approach is feasible and safe. Our report fulfills an unmet need by serving as a guide for other clinicians who seek to transition their patients from disopyramide to mavacamten.

Astragaloside IV inhibits cardiac fibrosis via miR-135a-TRPM7-TGF-β/Smads pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiac fibrosis is a common characteristic of many cardiac diseases. Our previous results showed that TRPM7 channel played an important role in the fibrosis process. MicroRNA-135a was reported to get involved in the fibrotic process. Astragalus membranaceus (Fisch.) Bunge was widely used in Chinese traditional medicine and showed cardiac protective effects in previous researches. Astragaloside IV(ASG), which is regarded as the most important ingredient of Astragalus, has been showed the effect of cardiac protection via various mechanisms, while no data suggested its action related to miRNAs regulation.

AIM OF THE STUDY

The objective of this article is to investigate the inhibition effect of ASG on cardiac fibrosis through the miR-135a-TRPM7-TGF-β/Smads pathway.

MATERIALS AND METHODS

We extracted the active components from herb according to the paper and measured the content of ASG from the mixture via HPLC. The inhibition potency of cardiac hypertrophy between total extract of Astragalus and ASG was compared. SD rats were treated with ISO (5 mg/kg/day) subcutaneously (s.c.) for 14 days, ASG (10 mg/kg/d) and Astragalus extract (AE) (4.35 g/kg/d, which contained about ASG 10 mg) were given p.o. from the 6th day of the modeling. Cardiac fibroblasts (CFs) of neonatal rats were incubated with ISO (10 μM) and treated with ASG (10 μM) simultaneously for 24 h.

RESULTS

The results showed that both AE and ASG treatment reduced the TRPM7 expression from the gene level and inhibited cardiac fibrosis. ASG group showed similar potency as the AE mixture. ASG treatment significantly decreased the current, mRNA and protein expression of TRPM7 which was one of targets of miR-135a. The activation of TGF-β/Smads pathway was suppressed and the expression of α-SMA and Collagen I were also decreased obviously. In addition, our results showed that there was a positive feedback between the activation of TGF-β/Smads pathway and the elevation of TRPM7, both of which could promote the development of myocardial fibrosis.

CONCLUSIONS

AE had the effect of cardiac fibrosis inhibition and decreased the mRNA expression of TRPM7. ASG, as one of the effective ingredients of AE, showed the same potency when given the same dose. ASG inhibited cardiac fibrosis by targeting the miR-135a-TRPM7-TGF-β/Smads pathway.

Transient hypertrophic cardiomyopathy and hypertension associated with hydrocortisone in preterm infant: A case report

RATIONALE

Hypertrophic cardiomyopathy (HCM) is a heterogeneous, usually familial disorder of heart muscle. The hypertrophic form of cardiomyopathy is frequently genetic, or as part of several neuromuscular disorders. In neonates, especially prematurity, HCM could also be secondary to corticosteroid treatment.

PATIENT CONCERNS

We reported here a 34 weeks gestational age preterm infant presented with profound cardiomegaly after multiple doses of hydrocortisone used to treat blood pressure instability associated with septic shock and persistent pulmonary hypertension (PPHN).

DIAGNOSIS

Patient presented auscultation of a grade III/IV harsh systolic ejection murmur from day 14, which was absent before. Profound cardiomegaly was indicated at chest film at day 30. Echocardiography showed severe thickening of the IVS (13.8 mm, z score = 8.29) and mild thickening of the posterior left ventricular wall (LVPW, 6 mm).

INTERVENTIONS

Propranolol and captopril were started along with supportive care. The patient was also admitted to NICU for further treatment with 24-hour Holter electrocardiographic monitoring.

OUTCOMES

A reversible course was observed without left ventricular outflow tract obstruction nor arrhythmias within 4 weeks.

LESSONS

The risk/benefit ratio must be carefully considered when corticosteroids are used in prematurity. Monitors such as echocardiography and electrocardiograph should be conducted in order to guide cardiovascular management. Systematic surveys of the incidence of cardiac complications in a larger population of preterm infant treated with corticosteroid are needed in the future.

[Effects of ligustrazine on the mitochondrial structure and functions in the process myocardial hypertrophy]

OBJECTIVE

To explore changes of mitochondrial structure and functions, as well as the protection of ligustrazine in the process of myocardial hypertrophy.

METHODS

Neonatal myocardial cells were isolated and cultured with angiotensin II (Ang II) for 72 or 96 h. The total protein content was detected using BCA method. The cell diameter was measured by inverted microscope, by which to reflect the proliferation situation of cardiomyocytes. The mitochondrial membrane potential (MMP) was measured by fluorescence microscope. The mitochondrial monoamine oxidase (MAO) activity was detected by spectrophotometer. The mitochondrial cytochrome oxidase (COX) activity and the mitochondrial damage percentage were detected by microplate reader, by which to reflect the damage of mitochondrial outer membrane's structure and the membranes' function. Also, cells were treated with ligustrazine and losartan and then the pharmacological effects on the mitochondrial structure and functions in the myocardial cells treated with Ang II were observed.

RESULTS

At 72 h and 96 h, when compared with the blank group, cells treated with Ang II had increased total protein content (P < 0.01) and enlarged diameter (P < 0.01). Treated with Ang II, the MAO activity and the outer membrane damage percentage of myocardial cells significantly increased (P < 0.01), and mitochondrial COX activity and the mitochondrial MMP significantly decreased (P < 0.01). Compared with the model group at the same time period, ligustrazine significantly reduced myocardial cells' total protein content and myocardial cell diameter, and significantly decreased myocardial cells' MAO activity, increased mitochondrial COX activity, improved the outer membrane damage percentage and inner membrane MMP at 72 and 96 h, all showing statistical difference (P < 0.01, P < 0.05).

CONCLUSIONS

During the process of myocardial hypertrophy existed the damage to the mitochondrial structure and functions. Ligustrazine protected the mitochondrial structure and functions of the myocardial cells in reversing Ang II induced myocardial cell hypertrophy.

Tacrolimus-related hypertrophic cardiomyopathy in an adult cardiac transplant patient

Left ventricular hypertrophy associated with the use of tacrolimus is a rare complication of solid organ transplantation in adult recipients. We present a cardiac transplant recipient who developed severe concentric left ventricular hypertrophy with congestive heart failure related to myocardial hypertrophy on tacrolimus. Hypertrophy improved when the drug was discontinued and replaced with sirolimus.

The perils of pharmacological treatment for obesity: a case of sibutramine-associated cardiomyopathy and malignant arrhythmias

A 58-year-old woman presented with severe left ventricular dysfunction and malignant arrhythmias after taking combination drug treatment for weight loss. The combination treatment included sibutramine, liothyronine, hydrochlorothiazide diuretic, metformin and fucus. The effect of these drugs individually and in combination is discussed, with particular reference to it being a malignant combination. The patient showed reversability of the left ventricular dysfunction and negative ventricular stimulation studies after cessation of the drug concoction.

[Right ventricular hypertrophic cardiomyopathy in the fetus --may it be caused by chronic oral tocolysis with fenoterol?]

The use of fenoterol in the treatment of preterm labor is associated with the risk of many complications in the mother and the fetus. We present a case of a multipara treated with oral fenoterol due to threatening preterm labor 14 weeks. At 35 weeks of gestation the fetus was diagnosed with hypertrophic cardiomyopathy with severe impairment of the right ventricle. The only factor that might have caused such a state of the fetal circulatory system was fenoterol, used from 21 weeks of gestation. After the withdrawal of the fenoterol the fetal right ventricular function improved gradually. However fetal cardiac hypertrophy persisted until the birth at 39 weeks of gestation. Concentric hypertrophy of the right ventricular wall and interventricular septum were confirmed in the newborn.

Morton lentil extract attenuated angiotensin II-induced cardiomyocyte hypertrophy via inhibition of intracellular reactive oxygen species levels in vitro

The objective was to investigate whether a lentil (Morton) extract had any protective effect on cardiac hypertrophy, which is one of the most significant sequelae of cardiovascular diseases. High phenolic compounds (43.4 mg of GAE/g), including thirteen phenolic acid and two flavonoids, were detected in the acetone/water/acetic acid lentil extract. The extract showed strong antioxidant ability (105 μmol of TE/g). The effect of lentil extract on angiotensin (Ang) II-induced cardiac hypertrophy was examined. Results showed that pretreatment with lentil extract (25, 50, 100 μg/mL) significantly attenuated Ang II (0.1 μM)-induced hypertrophy by 18, 28, and 36% in rat cardiomycytes, respectively; lentil extract (12.5, 25, 50 μg/mL) attenuated Ang II (0.1 μM)-induced hypertrophy by 9, 17, and 25% in human cardiomycytes, respectively. Intracellular reactive oxygen species (ROS) levels were enhanced by Ang II treatment, and this stimulatory action was significantly attenuated (33% inhibition) by lentil extract (100 μg/mL) in rat cardiomyocytes and attenuated by 22% by 50 μg/mL lentil extract in human cardiomyocytes. In conclusion, Morton lentil extracts attenuated Ang II-induced rat and human cardiomyocytes hypertrophy via decreasing intracellular ROS levels.

Estrogen delays the progression of salt-induced cardiac hypertrophy by influencing the renin-angiotensin system in heterozygous proANP gene-disrupted mice

Left ventricular hypertrophy is considered an independent risk factor for cardiac morbidity and mortality, and many studies have shown that women have a lower incidence of left ventricular hypertrophy even after correcting for numerous risk factors. This cardio-protective effect seen in women has been attributed to estrogen, which likely modulates specific growth-promoting systems such as the renin-angiotensin system, and in turn may lead to the prevention of left ventricular hypertrophy. Furthermore, the underlying mechanisms responsible are poorly understood. The aim of the present study was to examine the effect of estrogen in relation to its impact on the development of left ventricular hypertrophy through its interaction with the renin-angiotensin system by using the proANP heterozygous (ANP +/-) mouse as a model of salt-sensitive cardiac hypertrophy. Male, female ANP +/- mice and also ovariectomized female ANP +/- mice treated with oil or estrogen, were fed either a normal or high-salt diet. All four groups exhibited a general suppression of the renin-angiotensin system under the high salt challenge. However, after the 5-week treatment period, marked left ventricular hypertrophy was noted only in the male and oil-injected ovariectomized female ANP +/- mice treated with high salt. Collectively, we provide direct evidence that the differences in cardiac hypertrophy between genders in ANP +/- mice is attributed to estrogen. Furthermore, estrogen may play a key role in slowing down the progression of salt-induced left ventricular hypertrophy in ANP +/- mice, in part, independent of the classical systemic renin-angiotensin system and possibly through other pathways.

Reversal of tacrolimus-related hypertrophic cardiomyopathy after conversion to rapamycin in a pediatric liver transplant recipient

Tacrolimus (Tac)-related hypertrophic cardiomyopathy (HCM) has been reported to be an unusual but serious complication affecting pediatric patients after solid organ transplantation. Herein, we present a case of young liver transplant recipient with Tac-induced HCM, treated by discontinuation of Tac followed by conversion to rapamycin (Rap). Our case report points out the potential but rather low risk of HCM during Tac immunosuppression in pediatric liver transplants and demonstrates that replacement of calcineurin inhibitors with mammalian target of Rap (mTOR) inhibitors may be an efficacious therapeutic tool to effect regression of established cardiac hypertrophy.

Contributory role of VEGF overexpression in endothelin-1-induced cardiomyocyte hypertrophy

Although endothelin-1 (ET-1) stimulates vascular endothelial growth factor (VEGF) expression in a variety of cells, including endothelial cells and vascular smooth muscle cells, the effects of ET-1 on expression of VEGF and its receptors in cardiomyocytes are unknown. In the present study, we found that treatment of neonatal rat cardiomyocytes with ET-1 for 24 h resulted in upregulation of VEGF and its two principal receptors, fetal liver kinase 1 and fms-like tyrosine kinase 1, in a concentration-dependent manner (10(-12) to 10(-6) M). ET-1 treatment also caused significant cardiomyocyte hypertrophy, as indicated by increases in cell surface area and [(14)C]leucine uptake by cardiomyocytes. Treatment with TA-0201 (10(-6) M), an ET(A)-selective blocker, eliminated ET-1-induced overexpression of VEGF and its receptors as well as cardiomyocyte hypertrophy. Treatment with VEGF neutralizing peptides (5-10 mug/ml) partially but significantly inhibited ET-1-induced cardiomyocyte hypertrophy. These results suggest that ET-1 treatment of cardiomyocytes promotes overexpression of VEGF and its receptors via activation of ET(A) receptors, and consequently the upregulated VEGF signaling system appears to contribute, at least in part, to ET-1-induced cardiomyocyte hypertrophy.

Thyroid hormone downregulates the expression and function of sarcoplasmic reticulum-associated CaM kinase II in the rabbit heart

Phosphorylation of sarcoplasmic reticulum (SR) Ca2+-cycling proteins by a membrane-associated Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) is a well-documented physiological mechanism for regulation of transmembrane Ca2+fluxes and the cardiomyocyte contraction-relaxation cycle. The present study investigated the effects of l-thyroxine-induced hyperthyroidism on protein expression of SR CaM kinase II and its substrates, endogenous CaM kinase II-mediated SR protein phosphorylation, and SR Ca2+pump function in the rabbit heart. Membrane vesicles enriched in junctional SR (JSR) or longitudinal SR (LSR) isolated from euthyroid and hyperthyroid rabbit hearts were utilized. Endogenous CaM kinase II-mediated phosphorylation of ryanodine receptor-Ca2+release channel (RyR-CRC), Ca2+-ATPase, and phospholamban (PLN) was significantly lower (30–70%) in JSR and LSR vesicles from hyperthyroid than from euthyroid rabbit heart. Western immunoblotting analysis revealed significantly higher (∼40%) levels of sarco(endo)plasmic reticulum Ca2+-ATPase isoform 2 (SERCA2) in JSR, but not in LSR, from hyperthyroid than from euthyroid rabbit heart. Maximal velocity of Ca2+uptake was significantly increased in JSR (130%) and LSR (50%) from hyperthyroid compared with euthyroid rabbit hearts. Apparent affinity of the Ca2+-ATPase for Ca2+did not differ between the two groups. Protein levels of PLN and CaM kinase II were significantly lower (30–40%) in JSR, LSR, and ventricular tissue homogenates from hyperthyroid rabbit heart. These findings demonstrate selective downregulation of expression and function of CaM kinase II in hyperthyroid rabbit heart in the face of upregulated expression and function of SERCA2 predominantly in the JSR compartment.

Reversal of tacrolimus-related hypertrophic obstructive cardiomyopathy 5 years after kidney transplant in a 6-year-old recipient

Hypertrophic obstructive cardiomyopathy (HOCM) is an unusual but serious side-effect of tacrolimus (TAC) based immunosuppression primarily affecting pediatric patients after solid organ transplant. TAC-induced HOCM has already been described in patients after liver, bowel and heart transplant shortly after the procedure. Herein, we present the first case report of TAC-induced HOCM in a young renal transplant recipient 5 yr after renal transplant. The condition was diagnosed by ECHO and EKG and successfully treated by discontinuation of TAC followed by conversion to cyclosporine (CsA).

Left ventricular hypertrophy with outflow tract obstruction-a complication of dexamethasone treatment for subglottic stenosis

To our knowledge, this is the 1st reported case of steroid-induced obstructive cardiomyopathy in a child being treated for subglottic stenosis. As well, although born at 27 weeks, our patient was over 4 kg and 4 months of age (44 weeks corrected gestational age). This appears to be a phenomenon chiefly involving premature babies in the neonatal period with no reports of this occurring in patients greater than 40 weeks corrected gestational age. Signs of cardiac hypertrophy include tachycardia, new cardiac murmur, increased oxygen requirements, decreased urine output, and decreased peripheral perfusion. Diagnosis and eventual recovery was confirmed with serial echocardiograms. Knowledge of this serious side effect of dexamethasone will allow otolaryngologists to intervene early and prevent a potentially deadly complication.

Chronic Nitric Oxide Synthase Inhibition Prevents New Coronary Capillary Generation

L-NAME-induced hypertension has been shown to produce concentric (eutrophic) remodeling of the heart despite an enhanced afterload. We postulated that nitric oxide synthase inhibition could limit coronary capillary growth to explain the nature of remodeling. To test our hypothesis, we aimed at determining the effect of endogenous and exogenous nitric oxide on coronary neovascularization. Aortic and coronary rings from normotensive animals were incubated in a three-dimensional type I collagen matrix in the presence of L-NAME or the nitric oxide donor SNAP. L-NAME inhibited, while SNAP stimulated, neovascularization from aortic and coronary rings after 12 days of in vitro incubation. In arterial rings harvested from rats treated with L-NAME for 14 days and in which no further in vitro treatment was added, only coronary rings showed a reduction in new capillary generation. While confirming that chronic L-NAME-treated rats develop concentric remodeling, the evaluation of capillary density did not reveal any difference as compared with the controls in 3 areas of the myocardium. In conclusion, chronic inhibition of nitric oxide synthesis in vivo produces a long-lasting reduction in the capacity of coronary arteries to generate new capillaries in vitro. Thus, our results lend support to the hypothesis that an inhibition of new capillary formation could prevent the development of compensatory ventricular hypertrophy, in favor of concentric remodeling.

Cardiomyopathie hypertrophique compliquant une corticothérapie orale pour hémangiome palpébral

INTRODUCTION

Systemic corticosteroid therapy is the usual treatment for hemangioma with vascular risk. Tolerance to such treatment is usually good.

OBSERVATION

A two Month-old girl presented with a hemangioma of the lower right eyelid that had developed since she was 15 days old. Treatment with betamethasone at the dose of 0.3 mg/kg/day was prescribed because of the risk of alteration in sight. The treatment was highly effective. The discovery of a systolic cardiac murmur motivated a cardiac sonography that showed signs of an obstructive hypertrophic myocardiopathy. The progressive reduction of the corticosteroids led to the regression of this disease.

DISCUSSION

The onset of a cardiomyopathy during systemic corticosteroid therapy has only been reported exceptionally in the literature. There is little known of the risks. When in doubt, clinical and sonographic monitoring is probably necessary. In the case of the appearance of a cardiac murmur, the sonography is crucial.

Hemopericardium and cardiac tamponade as presenting findings of dexamethasone-induced hypertrophic cardiomyopathy complicated by transmural myocardial infarction

This is the first report of dexamethasone-induced left ventricular outflow obstruction causing decreased coronary artery perfusion and apical transmural cardiac infarct that resulted in hemopericardium and rapid cardiac tamponade. The differential diagnosis of hemorrhagic pericardial effusion must now include dexamethasone-induced hypertrophic cardiomyopathy.

Multicenter prospective investigation on cardiovascular adverse effects of tacrolimus in kidney transplantations

To clarify the incidence and pathophysiological mechanism of cardiovascular adverse effects of tacrolimus, the present prospective study performed scheduled cardiovascular examinations at 1, 2, 4, 8, 16, 20, and 24 weeks after starting the tacrolimus therapy in 68 consecutive kidney transplantation recipients enrolled from 26 institutes in Japan. Patients with previous coronary artery disease or congestive heart failure were excluded. The examinations included any subjective symptoms, changes in resting ECG, ambulatory Holter's dynamic ECG, two-dimensional echocardiography, and monitoring of serum drug concentrations and cardiac troponin T levels. Cardiac nuclear imaging and/or coronary angiography were performed in the case of suspicious coronary events. During the investigation, chest pain in 9 (13.2%) and palpitation in 6 patients (8.8%) were reported, both closely related to elevated blood drug concentrations (37.2 +/- 18.7 ng/mL, mean +/- SD). Cardiovascular examinations detected development of resting ECG abnormalities in 12 patients (17.6%), asymptomatic ST depression following increased heart rate in 11 (16.2%) and ventricular arrhythmias in 7 patients (10.3%) on Holter's dynamic ECG. Elevation of troponin T was detected in 3 patients (4.4%), which was also closely related to elevated drug concentrations and interpreted as myocardial damage associated with the therapy. Assessments by thallium(Tl)-201 myocardial scintigraphy and/or coronary angiography in patients with suspicious coronary events revealed only two patients (2.9%) were considered to be myocardial ischemia associated with coronary vasospasm or microcirculatory disturbance. Sequential evaluations on echocardiography revealed significant (p<0.05) decrease in LV end-diastolic dimension (4, 8, 18 and 24 weeks) and LV end-systolic dimension (from 1 to 24 weeks), and significant (p<0.05) increase in LV ejection fraction 1 to 4 weeks after the kidney transplantation. Thickening of LV wall (>2 mm compared with baseline) was detected in only one patient. The present prospective study detected totally 30.9% incidence of cardiovascular adverse events. Symptomatic events and troponin T elevation were closely related to elevated blood drug concentrations (>20 ng/ml). Coronary vasomotor dysfunction seemed to be related to these adverse events especially when the blood drug concentration was exceeding 20 ng/ml.

An unusual complication of the treatment of a hemangioma

A 3-month-old infant was administered high-dose systemic prednisolone for management of a hemangioma of the nasal sidewall. After 10 weeks of therapy, medical evaluation of weight loss disclosed hypertrophic obstructive cardiomyopathy. After discontinuation of the steroid, the cardiomyopathy resolved.

[Cardiac lesions in methamphetamine abusers]

Various cardiac lesions such as hypertrophy, disarray and fibrosis similar to HCM, were often found in the heart of methamphetamine (MA) abusers. Myolysis, eosinophilic changes, contraction band necrosis and small round cell infiltration were also observed. Male ddy mouse were administered MA 1 mg/kg subcutaneously every day for 4 weeks. Their hearts revealed many cardiac changes such as hypertrophy, myolysis, contraction band necrosis, disarrangement of myofibers, saw-like cytoplasm, side-to-side connection of cardiac cells and vascuolative degeneration microscopically, and crysterosis of mitochondria, enlargement of sarcoplasmic reticulum and hypercontraction electronmicroscopically. These changes are thought to be similar to that of MA abusers, so it is certified that MA has toxic effect on the heart. Moreover, these changes could not be found when beta-blocker or calcium antagonist was premedicated. To elucidate the mechanisms of MA cardiac toxicity, we have designed some experiments. When MA (15 mg or 20 mg/kg) was administered on rats, cardiac lipid peroxidates, as a marker of free radical, increased rapidly. When rats were feeded for 7 weeks with Vitamin E deficient diet, 10 mg/kg MA administration was enough to increase lipid peroxidates. Simultaneous ECG observation revealed various arrhythmia such as VPB, A-V block and intraventricular conduction delay. In the investigation of contractile protein, although we could not find differences in the isozyme pattern of myosin heavy chain between MA groups (1 mg/kg for 8 and 12 weeks) and control group, Mg2+ ATPase activity of myocardial actomyosin at 0.1 microM Ca2+ increased significantly in 12 weeks MA group. We also found MA induced cardiac toxicity in cultured myocytes. Primary cultured adult rat myocytes were exposed to MA (1 x 10(-5) M and 1 x 10(-3) M) for 1 to 24 h in the presence and absence of 1 x 10(-5) M propranolol. After 24-h MA treatment, cellular granulation, swelling and hypercontraction and release of CPK were observed both with and without propranolol treatment. These findings suggest that MA may exert direct toxic effects on the heart.

Lack of tacrolimus-induced cardiomyopathy

BACKGROUND

Hypertrophic cardiomyopathy (HCM) has been reported in pediatric transplant patients receiving tacrolimus. It is unclear whether tacrolimus is associated with HCM in adult transplant recipients.

OBJECTIVE

To determine the prevalence of HCM in noncardlac adult transplant patients receiving tacrolimus.

METHODS

A retrospective analysis of nonheart transplant recipients who received tacrolimus at our institution from January 1982 to April 1996 was conducted. Patients with left-ventricular hypertrophy (LVH) defined as a posterior or septal wall thickness > or = 1.3 cm by echocardiography (ECHO) were independently evaluated.

RESULTS

There were 3609 patients who met entry criteria including 2257 liver, 1333 kidney, and 19 other organ transplants. Of the 502 patients who had undergone ECHOs after transplantation, 171 had LVH. The etiology of LVH was categorized as valvular disease (36%), hypertensive disease (29%), ischemic heart disease (17%), or multifactonal (15%). There were six patients in whom, after detailed chart review, no underlying cause of LVH was evident. Five of these patients had HCM, representing an overall prevalence of 0.1% in the entire group of tacrolimus-treated patients, and 1% in patients referred for ECHO.

CONCLUSIONS

The prevalence of HCM in our tacrolimus-treated adult transplant population is similar to that reported in general population studies. These data suggest that tacrolimus is not a risk factor for HCM in adult transplant recipients.

[Bepridil inhibition on the delayed rectifier K+ currents in thyroxine induced hypertrophied guinea pig ventricular myocytes]

AIM

To study the effects of bepridil on the rapidly activating component (IKr), the slowly activating component (IKs) of the delayed rectifier potassium current and the inward rectifier potassium current (IK1) in hypertrophied guinea pig ventricular myocytes.

METHODS

The whole cell patch clamp techniques were used.

RESULTS

In hypertrophied guinea pig ventricular myocytes, bepridil 30 mumol.L-1 markedly inhibited IKr and IKs (by 20.9% and 27.2% at 0 mV and mV, respectively). The effect of bepridil on IKs was larger than on IKr. Bepridil 30 mumol.L-1 also significantly inhibited the inward component of IK1 (by 15.1% at +100 mV), but the reverse potential of IK1 was unaffected. Bepridil (1-100 mumol.L-1) was shown to inhibit IKr and IKs in a concentration-dependent manner. Their IC50 were 46.7 mumol.L-1 and 23.8 mumol.L-1, respectively.

CONCLUSION

Bepridil inhibit IKr, IKs and IK1 in hypertrophied guinea pig ventricular myocytes, which may be important in understanding the antiarrhythmic effects of this drug.

Echocardiographic findings of hypertrophic cardiomyopathy in children after orthotopic liver transplantation

This study was carried out to compare echocardiographic findings of children taking tacrolimus and cyclosporin A (CsA) after orthotopic liver transplantation (OLT). Echocardiograms of 19 children were reviewed during hospitalizations after OLT, and echocardiograms were performed on 23 children who returned to the clinic for a routine follow-up visit after OLT. Measurements were made of the left ventricle (LV) end-diastolic dimension, and of the thickness of the LV free wall (LVFW) and the inter-ventricular septum (IVS). From these measurements, the LV mass was calculated. LV outflow gradient was measured by using Doppler interrogation. Comparisons were made between patients on CsA and patients on tacrolimus. Children with hypertrophic cardiomyopathy (HCM) were identified. Two patients from the in-patient tacrolimus group were found to have HCM. These two patients had asymmetric septal hypertrophy with dynamic LV outflow obstruction and were successfully treated with propranolol, with or without discontinuing tacrolimus. In the out-patient studies, there was no difference in LVFW and IVS thickness, or LV mass index, between children on CsA and children on tacrolimus. Hence, tacrolimus is associated with the development of HCM in children. The effect of tacrolimus on HCM development may be acute and temporary. More data are needed to determine the incidence of HCM in children on tacrolimus therapy and to establish guidelines for clinicians who follow-up these children.

Steroid-induced hypertrophic cardiomyopathy following stem cell transplantation in a neonate: a case report

We report a case of severe left ventricular outflow tract obstruction complicating steroid therapy in an infant undergoing allogeneic transplant in the first few weeks of life for treatment of Krabbe's disease. While this complication is well known to those treating premature infants, it has not been reported in the stem cell transplant setting. For young infants undergoing allogeneic transplant who require steroid therapy, cardiac monitoring after 2--3 weeks of therapy is recommended.

Sirolimus in pediatric gastrointestinal transplantation: the use of sirolimus for pediatric transplant patients with tacrolimus-related cardiomyopathy

Hypertrophic obstructive cardiomyopathy (HOCM) associated with the use of tacrolimus is a rare complication of liver and intestinal transplantation seen almost exclusively among pediatric patients. Reduction of tacrolimus dosage or conversion to cyclosporin A (CsA) has been used as an effective treatment in reviewed cases. We present three pediatric transplant recipients who developed hypertrophic obstructive cardiomyopathy while under tacrolimus immunosuppression and were treated with conversion to sirolimus (Rapamycin). The patients (ages 6 yr, 12 yr and 11 months) were transplant recipients (liver, n = 2; liver and intestine, n = 1) who developed significant cardiomyopathy 15 and 96 months post-transplant. One patient died of post-transplant lymphoproliferative disorder 21 days after starting sirolimus. One patient had received two liver transplants and had been on CsA for 12 yr before conversion to tacrolimus at 60 months post-transplant for acute and chronic rejection. The surviving patients were receiving mycophenolate mofetil, tacrolimus and steroids at the time of diagnosis. Dose reduction of tacrolimus and treatment with beta blockers failed to alleviate the hemodynamic changes. The patients were converted to sirolimus 1.6, 37 and 148 months post-transplant and maintained a whole-blood trough level of 15-20 ng/mL 21 days after starting sirolimus. Repeat echocardiograms in the surviving patients showed improvement in cardiomyopathy. One patient had one rejection episode (intestinal biopsy, mild acute cellular rejection) after starting sirolimus that responded to a transient increase in steroids. The early demise of the third patient after sirolimus conversion prevented an adequate assessment of cardiomyopathy. Conversion to sirolimus was associated with a reduction in the cardiomyopathy of the two surviving patients while still providing effective immunosuppression. To our knowledge this observation has not been previously reported.

Transient hypertrophic cardiomyopathy in the newborn following multiple doses of antenatal corticosteroids

Postnatal exposure to steroids has been associated with hypertrophic cardiomyopathy (HCM) in the newborn. Such an effect has not been described in infants born to mothers who received antenatal steroids. We report three newborns whose mothers were treated with betamethasone prenatally in different doses, duration of time, and who developed various degrees of HCM diagnosed by echocardiography. There was no maternal evidence of diabetes except for one infant whose mother had a normal fasting and post-prandial blood glucose prior to steroid therapy, but an abnormal one hour postprandial glucose after 8 weeks of betamethasone therapy, with a normal HbA1 C level. There was no family history of HCM, no history of maternal intake of other relevant medications, and no hypertension in all three newborns. Follow-up echocardiography revealed complete resolution of the HCM changes in all infants. We suggest that repeated antenatal maternal steroid intake may cause changes of HCM in the newborn. These changes appear to be dose- and duration-related and are mostly reversible. Further prospective controlled studies to evaluate these observations and to investigate potential mechanisms are warranted.

Chloroquine cardiomyopathy with conduction disorders

A 58 year old woman on long term treatment with chloroquine for systemic lupus erythematosus presented with cardiac conduction disorders and heart failure with hypertrophic cardiomyopathy, which was confirmed by histology to be related to chloroquine toxicity. The heart failure improved on stopping chloroquine treatment.

Left ventricular wall thickening does occur in elite power athletes with or without anabolic steroid Use

Reports on the occurrence of left ventricular wall thickening in resistance-trained athletes have rejected the possibility for this physiological adaptation to occur without concomitant anabolic steroid abuse. Others have concluded short bursts of arterial hypertension that occur with maximal weight lifting are not sufficient to induce left ventricular wall thickening, and left ventricular wall thickness >/=13 mm should not be found in pure resistance-trained athletes. Therefore, we examined 4 elite resistance-trained athletes by two-dimensional echocardiography. In addition, we retrospectively examined the individual left ventricular dimensions of 13 bodybuilders from our previous echocardiographic studies. All 4 elite resistance-trained athletes had left ventricular wall thicknesses beyond 13 mm. One of the elite bodybuilders has the largest left ventricular wall thickness (16 mm) ever reported in a power athlete. Retrospectively, 43% of the drug-free bodybuilders and 100% of the steroid users had left ventricular wall thickness beyond the normal range of 11 mm. In addition, 1 drug-free subject and 3 steroid users were beyond the critical mark of 13 mm. No subjects demonstrated diastolic dysfunction. In contrast to previous reports, we have demonstrated that left ventricular wall thicknesses >/=13 mm can be found routinely in elite resistance-trained athletes. The use of anabolic steroids concomitant with intensive resistance exercise does appear to augment left ventricular size without dysfunction. Anabolic steroids may accelerate left ventricular wall thickening indirectly by increasing strength, thus augmenting the pressor response.

Effect of beta-blockade on symptomatic dexamethasone-induced hypertrophic obstructive cardiomyopathy in premature infants: three case reports and literature review

OBJECTIVE

The objective of this study was to assess the efficacy of beta-blockade on clinically significant left ventricular outflow tract obstruction in premature infants treated with dexamethasone because of bronchopulmonary dysplasia.

STUDY DESIGN

Case reports are presented of three premature infants (mean gestational age 27 weeks) cared for in the intensive care nursery in whom clinically significant septal hypertrophy and left ventricular outflow tract obstruction developed during dexamethasone treatment for bronchopulmonary dysplasia. The infants were treated with oral propranolol. Serial physiologic and echocardiographic parameters were followed. Physiologic data were analyzed with an analysis of variance, with the Kruskal-Wallis test used for nonparametric data. A p value < 0.05 was considered statistically significant.

RESULTS

Oral administration of the beta-blocker propranolol resulted in clinical and echocardiographic improvement of the left ventricular outflow tract obstruction. One patient had a lower average heart rate and two patients had lower average mean blood pressure values during propranolol treatment, none of which was clinically significant. None of the patients had worsening of the respiratory status.

CONCLUSION

beta-blockade treatment was well tolerated and may be beneficial in relieving symptomatic steroid-induced left ventricular outflow tract obstruction in premature infants.

Arteritis and increased intracellular calcium as a possible mechanism for tacrolimus-related cardiac toxicity in a pediatric transplant recipient

We recently reported partially to wholly reversible hypertrophic cardiomyopathy, including severe hypertrophic obstructive cardiomyopathy, as a side effect in pediatric transplant recipients receiving tacrolimus immunosuppression. This seemed to be dose related. We describe a pediatric patient receiving tacrolimus who died 3 weeks after liver/bowel transplantation. Postmortem findings revealed arteritis of cardiac arteries and extensive calcification of cardiac tissue suggesting a possible mechanism of tacrolimus cardiac toxicity. This is consistent with recent reports of tacrolimus increasing calcium release into the sarcoplasmic reticulum of cardiac and striated muscle.

Hypertrophic cardiomyopathy in preterm infants treated with dexamethasone

Steroid therapy has been widely used in neonates for its beneficial effects. Adverse side-effects have been described, also affecting the cardiovascular system. We report two cases of hypertrophic cardiomyopathy in two preterm newborns secondary to dexamethasone treatment. Full recovery occurred after discontinuing steroids. Risk/benefit ratios must be carefully considered before using steroids in the neonatal period.

CONCLUSION

Serial echocardiographic evaluations should be performed to evaluate prevalence and clinical relevance of hypertrophic cardiomyopathy in preterm infants treated with dexamethasone.

[Glucocorticoid-induced hypertrophic cardiomyopathy in premature infants: apropos of 4 cases]

BACKGROUND

The steroidal treatment used to prevent bronchopulmonary dysplasia (BD) in the preterm babies may be the cause of several complications, one of them being hypertrophic cardiomyopathy.

CASE REPORT

Four infants developed hypertrophic cardiomyopathy during glucocorticoid (dexamethasone and/or betamethasone) treatment for bronchopulmonary dysplasia. In one of them, septal hypertrophy led to left ventricular outflow tract obstruction and congestive heart failure. All four were premature infants born after 2 weeks of gestation and weighing 780 to 1,080 g. The first echocardiographic changes appeared between the 4th and 15th day of the glucocorticoid course when the cumulated dose was respectively 1.82-1.87-3.51 and 3.86 mg/kg. Hypertrophic cardiomyopathy resolved completely between 2 and 4 weeks after cessation of the treatment.

CONCLUSION

The glucocorticoid dosage to prevent BD should be reduced to 0.3 mg/kg/j and the myocardial function should be monitored by repeated echocardiograms during the first 15 days of treatment.

[Hypertrophic cardiomyopathy complicating a prolonged corticotherapy for hemorrhagic rectocolitis]

BACKGROUND

The cardiac side-effects of corticosteroid therapy are very uncommon.

CASE REPORT

A girl with ulcerative colitis developed at the age of 8 years an acute digestive episode despite prednisolone and total parenteral nutrition. The patient was then given intravenous methylprednisolone (2 mg/kg/d). Polypnea appeared 25 days later while blood pressure remained normal. Echocardiography revealed a cardiac hypertrophy associated with a systolic anterior motion of the mitral valve. Cardiac symptoms and echography findings returned to normal after reduction of corticosteroid therapy and its administration via the oral route.

CONCLUSION

Hypertrophic cardiomyopathy has been described in preterms treated with dexamethasone for bronchopulmonary dysplasia. It is exceptional in older children under corticosteroid therapy and its mechanism remains unknown.

Iatrogenic neonatal hypertrophic cardiomyopathy

Transient hypertrophic cardiomyopathy is a rare sequela of both glucocorticoid and insulin excess. We report two ELBW infants who developed hypertrophic cardiomyopathy as an iatrogenic complication of the concurrent therapeutic administration of a glucocorticoid and insulin. In both cases the hypertrophic cardiomyopathy resolved completely on cessation of therapy. We advise caution when using this therapeutic combination and stress the need for regular echocardiography.

Cardiac effects of dexamethasone in very low birth weight infants

OBJECTIVE

To characterize the cardiac effects of dexamethasone in very low birth weight infants.

DESIGN

Prospective, randomized, placebo-controlled, double-blind trial. Enrolled subjects were randomized to receive either a 42-day tapering course of dexamethasone or a saline placebo. Echocardiographic measurements were obtained on days 0, 7, 14, 28, and 42.

SUBJECTS

Thirteen infants received dexamethasone and 13 a saline placebo. The two groups were similar in birth weight, gestational age, age at enrollment, and sex/ race composition.

RESULTS

Patients receiving dexamethasone had a significantly larger increase in septal thickness on days 7, 14, and 28 and left ventricle (LV) posterior wall thickness on day 14. A significantly lower left ventricular end-diastolic dimension in the dexamethasone group was initially noted on day 7 and persisted until day 42. With the reduced left ventricular end-diastolic dimension, no significant differences in LV mass were noted, despite the increased wall thickness. No differences in LV systolic function, as assessed by area shortening, were seen. Assessment of diastolic function showed a significant increase in the atrial portion of mitral inflow in dexamethasone patients on day 14, as well as a significant prolongation in isovolumic relaxation time on days 7, 14, and 28.

CONCLUSIONS

Infants receiving dexamethasone developed evidence for impaired LV filling with a lager increase in wall thickness but no increase in LV mass, asymmetric septal hypertrophy, or augmented systolic function. This suggests that alterations in left ventricular filling play an important role in the development of hypertrophy seen with dexamethasone administration.

[Long-term selective beta 1-blockade therapy for a patient with anthracycline-induced cardiomyopathy]

A 44 year-old woman with acute myeloid leukemia (AML, FAB, M4E) developed heart failure during treatment with anthracyclines for AML. She had not experienced heart disease and her left ventricular ejection fraction (LVEF) was 59% at the end of a successful remission induction therapy. Because her LVEF decreased to 33% after early consolidation therapy, the chemotherapy for AML was discontinued. The cumulative dose of daunorubicin, aclarubicin and mitoxantrone was 486 mg/m2, 135 mg/m2 and 55 mg/m2, respectively. In October 1990, four months after the end of the chemotherapy, heart failure (class III, NYHA) developed and did not improve by treatment consisting of dobutamin, digoxin and diuretics. Anthracycline cardiomyopathy was histologically confirmed by endomyocardial biopsy. Then we administered selective beta 1-antagonist, metoprolol (Seloken), with an initial dose of 5 mg/day which was doubled 3 times every 4 or 8 weeks to 40 mg/day, according to the treatment schedule of dilated cardiomyopathy. She recuperated satisfactorily (Class I, NYHA), and was discharged on February '91. Her LVEF gradually improved and it has been maintained at above 50% on an outpatient basis. The patient has been in complete hematological remission during this period. It seems that low dose selective beta 1-antagonist therapy has a potential to improve myocardial function in some patients with anthracycline cardiomyopathy.