Aspirin and the Risk of Developing Myocardial Infarction in Patients with Acute Coronary Syndrome - Research Paper Example

? Does aspirin affect the risk of developing myocardial infarction in patients with acute coronary syndrome? Your al affiliationAbstract Myocardial infarction is serious coronary disease and there are many risk factors associated with it. These factors are; age, gender, positive family history of MI, high blood pressure, obesity, high levels of cholesterol, lack of physical activity, diabetes, stress, hypertension, increased serum triglycerides, excessive intake of saturated fats, salt and carbohydrates. Those drugs which are selective cyclooxygenase-2 inhibitors and those that are nonselective nonsteroidal anti-inflammatory, have been shown to increase the risk of reinfarction. This study will be hospital based and hopes to collect enough data to find out whether aspirin increases the risk of developing myocardial infarction in patients with acute coronary syndrome. Myocardial infarctions or acute myocardial infarction (MI) is commonly called heart attack and is a serious disease of coronary which occurs due hardening or narrowing of arteries when cholesterol plaque builds up. Blockage of arteries leads to a major reduction of blood supply, consequently causing necrosis (death or damage) of heart muscles (myocardium) or myocardium ischemia as the heart muscles are not served with oxygenated blood for quite some time (Imagins website:The women health resource,Overview of myocardial infarction, 2009).The infarction site depends on which vessels are involved. For example, if blockage occurs in circumflex coronary artery, this leads to lateral MI while blockage of right coronary artery can lead to right sided heart failures (Imagins website:The women health resource,Overview of myocardial infarction, 2009) There are many predisposing factors to the higher number of MI cases. Some of these factors can be controlled while others cannot. These factors are; age, gender, positive family history of MI, high blood pressure, obesity, high levels of cholesterol, lack of physical activity, diabetes, stress, hypertension, increased serum triglycerides, excessive intake of saturated fats, salt and carbohydrates (Ridker et al, 1998; Salim et al, 2004 ). Other risk factors includes, sedentary life, increased homocysteine and C -resistance proteins and use of drugs such as amphetamines and cocaine (Haffner, Seppo, Tapani, Kalevi and Markku, 1998). About 20% of patients with MI have diabetes (Salim et al, 2004).Obesity on its own or in combination with other factors, increases the risk of developing coronary disease (Khandekar, Khurana, Kakrani, Katdare and Inamdar, 2006). The symptoms of MI are; arm, epigastric and chest pain, breath shortness, diaphoresis, clammy skin dizziness, nausea, vomiting, angina frequency, fatigue, presence of pericardial friction rub, systolic murmurs, bradycardia, hypertension, absence of jagular vein distension, activity intolerance, decreased cardiac output, anxiety, among others (Imagins website:The women health resource,Overview of myocardial infarction, 2009) Diagnosis Diagnosis can be achieved through physical examination of symptoms. Other diagnostic tests which can be used are; detection of elevated levels of homocysteine and C- resistance proteins, electrocardiogram, use of cardiac troposin to differentiate between MI and injury of skeletal muscles. This can also be done through looking at the family history to identify if there is positive relationship. Identification of symptoms is important as this may help a clinician to refer the case to more qualified personnel if need be.The clinician should be able to clarify actual and potential health issues and the associated risk factors. Reflective thinking is also an important component during diagnosis. The clinician should be able to find out if the participation of the patient is optimal, if the data is complete and accurate, if there are assumptions identified and finally if conclusions are drawn from the facts of evidence obtained because there are other possible conclusions which can be drawn from the data obtained (Imagins website:The women health resource,Overview of myocardial infarction, 2009) Those drugs which are selective cyclooxygenase-2 inhibitors and those that are nonselective nonsteroidal anti-inflammatory, have been shown to increase the risk of reinfarction (Gunnar et al, 2006) .Recent studies have shown that, therapeutic trials with aspirin and heparin combination drugs, reduces the risk of incidence of myocardial infarction (Theroux, Walters, Qui, MCcans, P de Guise and Juneau, 1999; Khandekar et al, 2006).These drugs have shown to inhibit platelet formation and thrombin generation (Kandekar et al, 2006).Studies have shown that, dose incomplete generation of thromboxane can lead to occurrence of cardiovascular events (Eikelboom, Jack, Jeffrey, Marilyn, Qulong, Salim, 2002).Those patients with coronary syndrome usually have a range of therapeutic alternatives and the type of therapy used depends on the expected benefits and the clinical presentation of the disease (Boersma et al , 2000) . Studies have also shown that, aspirin reduces the risk of developing cardiovascular events by an estimate of 25% in patients with cardiovascular disease. Nevertheless, it has a limited effectiveness since 10-20% of all patients treated with aspirin and with arterial thrombosis have had recurrence of myocardial infarction at some point in the follow up (Theroux et al, 1999). Aspirin shows its antithrombotic affect by acetylating platelet cyclooxygenase 1 irreversibly and consequently inhibiting synthesis of thromboxane A2.There are also other poorly explained effects of asprin function of platelets but these effects are not certain (Theroux et al, 1999). Death is significantly reduced if aspirin (150mg daily) is taken daily when myocardial infarction is suspected. Treatment can be prescribed regardless of age, sex or diagnosis of diabetes or hypertension. It is beneficial and its risks are minimal. Almost all patients who could be having a myocardial infarction can take this drug and the treatment should be continued for a long term (NHS centerfor reviews and dissemination, 1995).This drug is also easier to administer. Some of the known contradictions or consequences of this drug are; hypersensitivity, peptic ulcers and also bleeding. Contraindications are also seen if a patient is treated with other drugs such as warfarin or any anticoagulant (NHS center for reviews and dissemination, 1995).In addition to this, gastrointestinal complications can also be seen. For those patients with acute myocardial infarction, prompt intravenous thrombolic therapy has been show to be very useful and effective. This is because delays may increase the start of symptoms (NHS center for reviews and dissemination, 1995).Intravenous therapy also reduces death occurrence significantly. Although there are other therapies which can be used instead of aspirin, these drugs are not very effective( NHS center for reviews and dissemination, 1995).Aspirin is prescribed for patients with angina, stroke,transient ischaemia attack, those with previous myocardial events and also for patients with angioplasty or by pass surgery (NHS center for reviews and dissemination, 1995). How aspirin therapy can reduce risk of myocardial infarction, stroke or death (NHS center for reviews and dissemination, 1995). Patient’s history Estimation reduction Previous myocardial infarction 25% Stroke/transient ischemic attack 22% Unstable angina 33% Peripheral vascular and valvular disease 20% For low heart disease and stroke , the approximations are not proven (NHS center for reviews and dissemination, 1995). There are a number of possible explanations of the reasons as to its limited efficacy. Firstly, it is well know that there are many pathways in which platelets can be activated, pathways which in aspirin does not block. In addition, high doses of aspirin ranging from 75- 325mg/d may be needed to obtain optimal antithrombolic effect in some patients (Theroux, et al, 1999). However, studies have shown that low doses of asprin are capable of blocking 95% of platelet cyclooxgynase activity and therefore, it is not very convincing that aspirin antithrombotic activity is linked to its dose (Theroux et al, 1999). This study hopes to determine whether aspirin affects the risk of developing myocardial infarction in patients with acute coronary syndrome. Hypothesis Null hypothesis -Aspirin could affect the risk of developing myocardial infarction in patients with acute coronary syndrome. Methodology Data will be collected as part of routine data collection information. Information on regular intake of aspirin in the month prior to admission and on discharge diagnosis will be collected. Regular intake of aspirin in this case, refers to daily aspirin intake. Information on the duration, dosage and frequency of aspirin use will be recorded. In final analysis of data, those patients whose first diagnosis is likely to be linked with aspirin use such as headache, cancer, different forms of arthritis, gastrointestinal bleeding, alcoholism, psychological disturbances and also anxiety, will be excluded. Those patients who are medically unfit for interview will also be excluded. Research design Follow up design will be used to compare those exposed to aspirin and those not exposed. The fundamental principle of this design is that there are equal risks of developing the myocardial infraction in both case and follow up groups. Data collection Data will be collected using questionnaires and interviews. Interviews will be contacted by trained people to avoid introduction of biasness. The patients will be asked about their past medical histories such as previous hypertension , myocardial infarction, diabetes, arthritis, rheumatic fever and a peptic ulcers. Ethical consideration Since this study will involve collection of information from patients, a written consent will be obtained from the medical institution. This will be particularly important so as to ensure confidentiality of the participants. Follow up and selecting of clinical outcomes All the patients will be followed up till completion of the study to ensure compliance. In each follow up, aspirin use outcomes will be recorded.The main outcome will be myocardial infarction. Statistical analysis of results Both descriptive and inferential statistics will be used. The mean proportion and medians for baseline demographics will be calculated. Multivariate analysis of data will be used to explore the association of aspirin use and the development of myocardial infarction. A multivariate score will be derived to characterize each individual risk of developing myocardial infarction. Such score will include history of myocardial infarction, peptic ulcers, antianginal drug user history. Correlation analysis will also be used to find association between the case and control group. Reporting of findings Information from this study can be shared through publications in journals, conferences or through other media. References Boersma, E., Pieper, K.S., Steyerberg, E.W., Robert, G, W, Wei-Ching, C., Lee, K.L., Martijin, A., Robert, A. H., Jaap, W.D., Armstrong, P.W., Michael, L., Robert, M,C., Eric, J.T and Maarten, L.S (2000). Predictors of outcome in patient with acute coronary syndrome without persistent st-segment elevation:Results from an international trial of 9461 patients ;. Journal of the American Heart association . doi: 10.1161/01.CIR.101.22.2557 NHS center for review and dissemination, N. c. (1995, April1). Effectiveness matters:Aspirin and myocardial infarction. Retrieved from www.york.ac.uk Eikelboom, J.W., Jack, H., Jeffrey, I.W., Marilyn, J., Qulong, Yi., Salim, Y. (2002). Aspirin resistant Thromboxane biosynthesis and the risks of myocardial infarction, stroke or cardiovascular death patients at high risk for cardiovascular events. Circulation , 105, 1650-1655. doi: 10.1161/01.CIR.0000013777.21160.07 Frans Ven de Weif., Jeroen,B., Amadeo, B., Carina,B.L., Filippo,C., Volkmar, F., Gerasimos, F.., Keith,F., Kurt,H., Adam, K., Annika, R.,Gabriel. S.P., Mario,T., Freek,V., Franz,W and Michael,W. (20008)."Management of acute myocardial infarction in patients presenting with persistent ST- segment elevation." European heart journal 29 . doi:10.1093/eurheartj/ehn416 Gunnar, H.G., Soren , J., Jeppe, N.R., Soren, R., Pernille, B., Jens, F., Tina, K.S, Steen, Z.A, Lars, K., Mette, M., Christian, T. P. (2006). Risk of death or reinfarction associated with the use of selective cyclooxygenase-2 inhibitor and Nonselective nonsteroidal antiinflammatory drugs after acute myocardial infarction. Journal of Americal Herat Association , 2906-2913. doi: 10.1161/CIRCULATIONAHA.106.616219 Haffner, S.M., Seppo,L., Tapani, R., Kalevi, P and Markku, L.,. "Mortality from coronary heart diseasesin subjects with type 2 diabetes and in non-diabetic subjects with and without myocardial infarction.(1998).The new England journal of medicine 339.4: 229-234. Imagins website:The women health resource,Overview of myocardial infarction. Retrieved from http://www.imaginis.com/heart-disease/heart-disease-myocardial-infarction-heart-attack Khandekar, M.M.,Khurana, A.S., Kakrani, A.L., Katdare, A,D and Inamdar, A.K (2006). Platelet volume indices in patients with coronary artery disease and acute myocardial infarction:an indian scenario. J. Clin Pathol , 59, 146-149. doi: 10.1136/jcp.2004.025387 Ridker, P.M., Nader, Rifai, Marc, A.P., Frank, M.S., Lemuel, A,.M., Steven, G., Greg, C.F and Eugene, B. (1998). Inflammation , pravastatin, and the risk of coronary events after myocardial infarction in patients with average cholesterol levels. Circulation , 98, 839-844. doi: 10.1161/01.CIR.98.9.839 Salim, Y., Steven,H., Stephania, O., Tony,D., Alvaro,A., Fernando, L., Mathew, M., Andrzej, B ., Prem, P., John,V and Liu, L. (2004)."Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study ) Case- control study.Retrieved from http://image.thelancet.com Theroux, P., Walters, D., Qui, S., MCcans, J, P de Guise and Juneau, M (1993). Asprin versus heparin to prevent myocardial infarction during the acute phase of nstable angina. Journal of American herat association .Circulation ,88, 2045-2048.doi: 10.1161/01.CIR.88.5.2045 Read More