Acute cardiovascular events

Elevated levels of lipoprotein-associated cholesterol in the blood, particularly that associated with LDL but also that in the more triacylglycerol-rich lipoproteins, are associated with the formation of cholesterol-rich atheromatous plaque in the vessel wall, eventually leading to diffuse atherosclerotic vascular disease resulting in acute cardiovascular events, such as a myocardial infarction, a stroke, or symptomatic peripheral vascular insufficiency. High levels of HDL in the blood, therefore, are believed to be vasculoprotective, because these high levels increase the rate of reverse cholesterol transport away from the blood vessels and toward the liver ( out of harm s way ). 

Exercise tolerance (stress) testing (ETT) is recommended for patients with an intermediate probability of CAD. Results correlate well with the likelihood of progressing to angina, occurrence of acute MI, and cardiovascular death. Ischemic ST-segment depression during ETT is an independent risk factor for cardiovascular events and mortality. Thallium myocardial perfusion scintigraphy may be used in conjunction with ETT to detect reversible and irreversible defects in blood flow to the myocardium. 

The sudden deaths of workers in the explosives industry have been attributed to a series of cardiovascular events that occur after repeated occupational exposures (Carmichael and Lieben 1963). Acute exposures result in a depression of both the systolic and diastolic blood pressure. Continued exposure to low concentrations of nitrate esters produces a progressive rise in the diastolic blood pressure from the previously depressed level without a comparable rise in the systolic blood pressure. This narrowing of the pulse pressure combined with an increased diastolic pressure and high pulse rate, which occurs following cessation of exposure, may contribute to acute myocardial ischemia. 

Rapamycin (sirolimus), a macrolide antibiotic, has been used recently in organ transplantation for its potent immunosuppressive actions by inhibiting both cytokine mediated and growth factor mediated proliferation of smooth muscle cells and lymphocytes [55, 56]. In the RAVEL trial of non-acute single vessel lesions, the Sirolimus-eluting stent was compared to bare metal stent (BMS) in a 1 1 fashion [57]. One-year major adverse cardiovascular events and 6 month neointimal proliferation as assessed by late luminal loss (-0.01 0.33 mm in Sirolimus stent versus 0.80 0.53 mm in BMS) were improved. The Sirolimus-eluting stent thus virtually eliminated in-stent restenosis with no evidence of edge effect, dissection, or in-stent thrombosis. 

Virtanen, J. K., Voutilainen, S., Rissanen, T. H., Mursu, J., Tuomainen, T. P., Korhonen, M. J., Valkonen, V. P., Seppanen, K., Laukkanen, J. A., and Salonen, J. T. (2005). Mercury, fish oils, and risk of acute coronary events and cardiovascular disease, coronary heart disease, and all-cause mortality in men in eastern Finland. Arterioscler. Thromb. Vase. Biol. 25, 228-233. 

Wallentin L. Prevention of cardiovascular events after acute coronary syndrome. Semin Vase Med. 2005 5 293-300. 

Antithrombotic therapy for acute peripheral occlusive disease is largely empirical. Thrombolytic therapy typically is reserved for patients in whom the occlusion is not amenable to surgery and for those in whom a possible delay between the initiation of therapy and thrombolysis would not jeopardize the viability of the limb. Evidence that antithrombotic therapy changes the natural course of the peripheral disease is sparse, but these patients are at an increased risk of cardiovascular mortality and should receive long-term aspirin therapy. Initial trials suggest that ticlopidine may improve the symptoms of chronic arteriosclerotic arterial insufficiency and also reduce fatal and nonfatal cardiovascular events, but further studies are needed. 

Mehta SR, Eikelboom JW, Rupprecht HJ, et al. Efficacy of hirudin in reducing cardiovascular events in patients with acute coronary syndrome undergoing early percutaneous coronary intervention. Eur HeartJ 2002 23 1 17-123. 

Patients with acute coronary syndromes such as acute myocardial infarction and unstable angina remain at risk for recurrent myocardial ischemia despite therapy with antiplatelet agents and heparin. Although first clinical trials indicate a possible use of oral direct TIs for the prevention of cardiovascular events in patients after acute myocardial infarction, the presently available data are still limited and it has not... 

Cuisset T Frere C, Quilici J, et al, High post-treatment platelet reactivity identified low-responders to dual antiplatelet therapy at increased risk of recurrent cardiovascular events after stenting for acute coronary syndrome, J Thromb Haemost 2006 4 542-549. 

Bonaa KH, et al. Homocysteine lowering and cardiovascular events after acute myocardial infarction. N Engl J Med 2006. 

The role of the sympathetic nervous system in renal injury, end-stage renal disease, and renovascular hypertension are discussed through a literature review accompanying sympathetic nerve mechanisms in hypertension and obesity. Relevant studies of sympathetic nerve activity and 32-adrenoceptor polymorphism might contribute to the onset and maintenance of renal injury in healthy subjects and in patients with chronic heart failure and cardiovascular events in ESRD patients. A better understanding of the relationships of sympathetic nerve activity with renal injury might help clinical implications (treatment) for renal injury in hypertensive patients and hypertension in patients with ESRD. Recently, the role of denervation of renal sympathetic nerve in refractory hypertension has been examined and showed its efficacy in humans. The outcome from the study have not been established, but a number of animal studies show theoretical benefits for those patients in the acute phase. Further studies are needed to clarify the relationships between the sympathetic nerve activity and renal injury. 

As cocaine use has become more widespread, the number of cocaine-related cardiovascular events has increased (39). Myocardial ischemia and infarction associated with cocaine are unrelated to the route of administration, the amount taken, and the frequency of use. The risk of acute myocardial infarction is increased after acute use of cocaine and it can occur in individuals with normal coronary arteries at angiography. The patients are typically young men and smokers and do not have other risk factors for atherosclerosis. 

Cocaine use may account for up to 25% of acute myocardial infarctions among patients aged 18-45 years. The safety of a 12-hour observation period in a chest pain unit followed by discharge in individuals with cocaine-associated chest discomfort who are at low risk of cardiovascular events has been evaluated in 302 consecutive patients aged 18 years or older (66% men, 70% black, 84% tobacco users) who developed chest pain within 1 week of cocaine use or who tested positive for cocaine (59). Cocaine use was self-reported by 247 of the 302 subjects and rest had urine positive for cocaine 203 had used crack cocaine, 51 reported snorting, and 10 had used it intravenously. Of the 247 who reported cocaine use, 237 (96%) said they had used it in the week before presentation and 169 (68%) within 24 hours before presentation. Follow-up information was obtained for 300 subjects. There were no deaths from cardiovascular causes. Four patients had a non-fatal myocardial infarction during the 30-day period all four had continued to use cocaine. Of the 42 who were directly admitted to hospital, 20 had acute coronary syndrome. The authors suggested that in... 

The second study was a case-control study sponsored by Merck Co (the manufacturers of celecoxib), in which the risk of acute thromboembohc cardiovascular events among 16 937 patients aged 40-75 years with rheumatoid arthritis using naproxen was examined using the British General Practice Research Database (52). Each patient with a first... 

The initial question must be whether the clinical data point to the emergence of complications of this type. The 1990 International Consensus Meeting found an increase in acute cardiovascular accidents during use of oral contraceptives, but not persisting after they had been discontinued. There is also a great deal of anecdotal evidence, although in view of the massive scale on which oral contraceptives have been used over 40 years, coincidence alone would lead to the accumulation of many reports of adverse events. Other evidence suggesting an increase in arterial thrombotic events has been noted incidentally in... 

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