Heart disease and erythropoietin

Comprehensive review of cardiovascular toxicity of drugs and related agents

Cardiovascular diseases are a leading cause of morbidity and mortality in most developed countries of the world. Pharmaceuticals, illicit drugs, and toxins can significantly contribute to the overall cardiovascular burden and thus deserve attention. The present article is a systematic overview of drugs that may induce distinct cardiovascular toxicity. The compounds are classified into agents that have significant effects on the heart, blood vessels, or both. The mechanism(s) of toxic action are discussed and treatment modalities are briefly mentioned in relevant cases. Due to the large number of clinically relevant compounds discussed, this article could be of interest to a broad audience including pharmacologists and toxicologists, pharmacists, physicians, and medicinal chemists. Particular emphasis is given to clinically relevant topics including the cardiovascular toxicity of illicit sympathomimetic drugs (e.g., cocaine, amphetamines, cathinones), drugs that prolong the QT interval, antidysrhythmic drugs, digoxin and other cardioactive steroids, beta-blockers, calcium channel blockers, female hormones, nonsteroidal anti-inflammatory, and anticancer compounds encompassing anthracyclines and novel targeted therapy interfering with the HER2 or the vascular endothelial growth factor pathway.

Meta-analysis of studies of patients in the United Arab Emirates with ST-elevation myocardial infarction treated with thrombolytic agents

We performed a meta-analysis of 6 studies we conducted in the United Arab Emirates from 1995 to 2009. These included 1,262 patients with ST-elevation myocardial infarction treated with thrombolytic drugs <6 hours after onset of symptoms and signs of myocardial infarction. All patients were treated with tenecteplase or alteplase to induce coronary thrombolysis. Characteristics of patients in all studies were quite similar. Overall mean age was 47 years, 98% were men, 28% had diabetes, 25% were hypertensive, 20% were hyperlipidemic, 56% were smokers, and 9% had sustained previous myocardial infarction. Incidence of adverse outcomes of 30-day mortality (3%), reinfarction (2.5%), stroke (0.4%), or major bleeding (0%) was low compared to global experience with recanalization regardless of how it was induced. There was no incidence of major bleeding requiring transfusion or laparotomy. In conclusion, in predominantly young men in the United Arab Emirates who were admitted and treated early after onset of an acute ST elevation myocardial infarction, recanalization induced by thrombolysis was an attractive therapeutic approach.

Erythropoietin to augment myocardial salvage induced by coronary thrombolysis in patients with ST segment elevation acute myocardial infarction

To determine whether the administration of erythropoietin (EPO) early after the onset of ischemia could enhance the preservation of jeopardized myocardium by reperfusion, 236 patients admitted <6 hours after the onset of chest pain indicative of acute coronary syndromes confirmed to be ST-segment elevation acute myocardial infarctions who were treated with tenecteplase to induce coronary thrombolysis were studied. Patients were randomized to standard care or standard care plus the administration of a single dose of EPO 30,000 IU intravenously immediately before the onset of treatment with tenecteplase. The primary end point was enzymatically estimated infarct size. The results indicated that infarct size index was virtually identical in the 2 groups, with a mean +/- SE of 13.2 +/- 0.1 creatine kinase-MB gram equivalents in controls and 12.4 +/- 0.9 creatine kinase-MB gram equivalents in patients treated with EPO. In conclusion, although the early administration of EPO was apparently safe, it did not enhance the preservation of jeopardized ischemic myocardium.

The magnitude and temporal dependence of apoptosis early after myocardial ischemia with or without reperfusion

In view of the conventional wisdom in the cardiology literature that apoptosis is extensive early after myocardial ischemia, predicated largely from results with the TUNEL assay known to be nonspecific, this study was performed to delineate its extent with multiple assays and at multiple intervals. Coronary occlusion with and without subsequent revascularization was induced in 10-wk-old C57BL6 mice subjected to 1 or 4 h of transient ligation followed by 24 h of reperfusion, or 24 h persistent ligation. Apoptosis was quantified throughout the left ventricle immunohistochemically by assay of TUNEL, single-stranded DNA (ssDNA), and cleaved caspase 3; electron microscopy (EM); and activity assays of caspase 3 and 8. TUNEL staining was marked, but ssDNA and cleaved caspase 3 staining were significantly less (P<0.001 compared with TUNEL), and apoptosis defined by EM was virtually absent in all groups. Caspase 3 and caspase 8 activities per milligram protein were not significantly different from those in normal hearts. Only rare, potentially apoptotic cells were seen by EM in hearts from any group. Thus, the results with TUNEL were not specific, and the extent of apoptosis was markedly less than that predicated on the results with the TUNEL procedure. Apoptosis is de minimus early after transitory or persistent ischemia, though it is overestimated by TUNEL assays. Thus, antiapoptotic interventions per se are not likely to preserve substantial amounts of myocardium early after ischemic insults.