Acute anthracycline cardiotoxicity. Comparative morphologic study of three analogues

Cardiac assessment of patients for haematopoietic stem cell transplantation

The expanding role of haematopoietic stem-cell transplantation (HSCT) renders the previous policy of avoiding transplantation in high-risk cardiac patients obsolete. Patients with amyloid, autoimmune conditions, sickle-cell disease, or thalassaemia, and patients over the age of 60 years are increasingly being offered HSCT. It is evident that the policy of avoiding transplantation in patients with impaired systolic function fails to identify all high-risk patients in such groups, and will deprive some patients of the benefits of HSCT unnecessarily. The development of an appropriate algorithm for cardiac pre-assessment and peri-transplant management is hampered by an inadequate understanding of the predictive value of various tests of cardiovascular function, the rapid evolution of advanced management strategies for cardiac dysfunction, and the development of non-cardiotoxic conditioning regimens. To meet this need we propose that an algorithm based on evidence from other clinical situations - already been found to be successful in the management of HSCT in patients with systemic sclerosis - should be used uniformly, and registry studies should be undertaken to distinguish those aspects of the algorithm that positively help to expand the remit of HSCT from those that add little of value.

Cardiac conduction abnormalities in patients with breast cancer undergoing high-dose chemotherapy and stem cell transplantation

Cardiac toxicities in 39 consecutive patients with breast cancer receiving high-dose chemotherapy (HDC) with stem cell transplantation were reviewed. All 39 patients received various anthracycline-containing regimens in adjuvant settings and/or for metastatic disease before HDC. As a cytoreductive regimen, all received cyclophosphamide 2000 mg/m2 and thiotepa 200 mg/m2 for 3 consecutive days. No immediate fatal toxicities were observed, but one patient developed chronic congestive heart failure and two had transient left ventricular dysfunction. Pericardial effusion was observed in another three patients. ST-T abnormalities during HDC were observed in two patients and arrhythmias were observed in nine, four of which occurred during stem cell infusion (SCI). There were three atrial arrhythmias, two ventricular arrhythmias, and four atrioventricular (AV)-block episodes. Two patients developed advanced and complete AV-block with an asystolic pause. Notably, three patients experienced AV-block with uncontrolled vomiting. No relationship was observed between the cumulative dose of anthracycline and cardiac toxicities during HDC. These results suggest that abnormalities in the conduction system during HDC may be more frequent than previously reported. Vagal reflex secondary to emesis may play an important role in the development of AV-block. Bone Marrow Transplantation (2000) 25, 185-189.

Doxorubicin-heparin complex: reduction of cardiotoxicity of doxorubicin

We have compared the antitumor activity and cardiotoxicity of free doxorubicin (Dox) and doxorubicin-heparin complex in vivo and in vitro. Dox and Dox-heparin complex equally inhibited the DNA synthesis of leukemic cells and showed a similar anticancer activity against tumor-bearing mice. Acute toxicity of Dox at the dose of 20 mg/kg or 30 mg/kg was significantly more profound than that of the Dox-heparin complex, which was demonstrated by survival rate (P < 0.01). Chronic toxicities of Dox and the Dox-heparin complex were compared by giving the respective reagent (2 mg/kg) weekly for 20 weeks. The weight gains of the mice given Dox-heparin complex were greater than those of the mice given Dox alone (P < 0.01). The pathological damage to the cardiac tissue in mice treated with Dox-heparin complex was significantly less severe than that of mice treated with Dox. Thus, the present study indicates that complexing with heparin diminished the acute and chronic toxicity of Dox without reducing its antitumor activity in mice, and suggests a possible clinical application of Dox-heparin complex in humans.

New data on the pharmacokinetics of adriamycin and its major metabolite, adriamycinol

Twenty-two days after administration by intravenous bolus, of 50 mg of adriamycin to several patients we found concentrations of adriamycin and adriamycinol of the order of 100 pcg/ml. In theory, however, with a terminal half-life of 30 h, the plasma levels of adriamycin and adriamycinol should be close to 0.1 pcg/ml. Further pharmacokinetic investigation was therefore necessary. We have retained for this study nine male patients, aged between 53 and 69 years who received 25 to 50 mg of adriamycin by slow intravenous injection. The HPLC method permitted the detection of 50 pcg/ml of adriamycin and adriamycinol, with the possibility of monitoring their elimination during 120 h (and in one case during 160 h). The terminal half-lives of elimination estimated in 8 patients were respectively 110 +/- 52 h for adriamycin and 92 h 50 min +/- 43 h for adriamycinol. Surface ratios under adriamycinol curves against calculated adriamycin was 1.10 +/- 0.26. Plasma levels found during the To in certain patients correspond to the end of the drug elimination of the previous treatment. It is difficult with a half-life to 110 h to predict the effects of residual concentrations of adriamycin and adriamycinol.

Cardiac arrhythmias in patients with small cell lung cancer and cardiac disease before, during and after doxorubicin administration. An evaluation of acute cardiotoxicity by continuous 24-hour Holter monitoring

Cardiac arrhythmias have been reported during doxorubicin infusion. The aim of the present study was to investigate the prevalence of arrhythmias and elucidate whether previous cardiac disease might increase the probability of treatment-related ectopic activity. In 18 patients with small cell lung cancer, 11 with concomitant heart disease, electrocardiogram (ECG) was continuously registered by a portable tape recorder 24 h before, during and 24 h after doxorubicin infusion (Holter monitoring). The only significant finding was an increased number of bigeminal ventricular extrasystoles after doxorubicin infusion. A trend of increased number of ventricular extrasystoles was also observed. The study suggests that pretreatment arrhythmias do not dispose for increased cardiac irritability and that bolus injections of doxorubicin do not seriously influence the ectopic activity in patients with and without heart disease.

Acute circulatory effects of doxorubicin in the conscious dog

Experimental work on the mechanisms of acute doxorubicin-induced cardiotoxicity may contribute to a better understanding of the clinical problem of cardiac failure after treatment with anthracycline derivatives. We studied aortic pressure and heart rate continuously for 1 h following a bolus injection of doxorubicin (1 mg/kg) in 7 dogs. In contrast with previous studies in intact animals, no anesthesia was used in order to eliminate possible interactions of doxorubicin with other drugs. One minute after doxorubicin injection a severe hypotension was observed, the average nadir in systolic and diastolic pressure being 62% and 42% of initial values. Surprisingly, the decrease in arterial blood pressure was not accompanied by cardiac acceleration. Doxorubicin, apparently interferes with the normal regulation of heart rate through the baroreceptor control system. Although several theories have been put forward regarding the mechanisms governing acute anthracycline cardiotoxicity, our knowledge of the phenomenon is still incomplete.