Clinical presentation and in-hospital outcome of patients with myocardial infarction admitted in Mulago hospital

Abstract

Background Myocardial infarction is one of the leading causes of mortality worldwide with decreasing incidence in developed countries and increasing incidences in developing countries, Uganda inclusive. This increasing trend has been attributed to urbanization and changing life styles in developing countries. There is high burden of risk factors like hypertension and diabetes mellitus in our setting Objectives To describe the clinical presentation and in-hospital outcome among patients admitted with myocardial infarction in Mulago hospital. Methods This was a prospective cohort study that was conducted in Mulago Hospital complex and Uganda Heart Institute. 54 subjects were recruited during the eight months study period. Data on clinical presentations, associated risk factors, laboratory and imaging findings, and complications were collected through standardized questionnaire. Blood samples were obtained for laboratory investigations. Participants were followed for minimum of two weeks and maximum of one month. Results A total of 54 patients were recruited, 29/54 (63%) had ST segment elevation myocardial infarction (STEMI) and 17/54(37%) had non-ST segment elevation myocardial infarction. Chest pain (66.7%) was the common presentation. Most patients in this study came to the hospital more than 72hours with median time of presentation to the hospital from onset of symptoms 93.5hours (SD 57.09, OR=1.002 95%CI 0.9-1.0). The mean age for the study participants was 58.7(SD=+/-10) with more males 38/54 (70.4%) than females 16/54(29.6%). Common associated symptoms were breathlessness 39/54(54.7%), palpitations 21/54(38.9%). Symptoms occurred at rest, with exercise and emotional stress. Only 7/59(13%) of the participants had low systolic and 11/54(20.4%) low diastolic blood pressure. 18/54(33.3%) had high systolic and 20/54(37%) diastolic pressure at admission. 19/54(35.2%) of participants had significant pulmonary rales at admission. 34/54(63%) had New York Heart Association class I and 40/54(74.1%) were in Killip class I. Risk factors include past medical history of hypertension 35/54 (OR=1.53, 95% CI=0.48-4.90), diabetes mellitus (OR=1.52, 95% CI=0.46-4.95), dyslipidaemia 7/54 (OR=1.73, 955CI=0.29-10.10), high LDL Cholesterol were higher risk for myocardial infarction. Low HDL (OR=1.9, 95% CI=0.55-6.58) confers higher risk for myocardial infarction compared to normal and high HDL cholesterol levels. Also similar patterns are seen in family history as positive for hypertension (59.3%) (OR=1.1, 955CI=0.35-3.88) and diabetes mellitus (37%). 50.9% of male and 92.9% of female participants had abdominal circumference greater than 102cm and 88cm respectively. Higher body mass index of 24.5-29.5(OR=2.0, 95%CI 0.3-13.1) and 29.5-39(OR=2.2, 95%CI=0.38-13.5) though the p value is not statistically significant was also a risk for myocardial infarction. Positive history of current or former h/o alcohol consumption constituted more than half of the participants (29/54). In contrast only approximately 13/54(24.1%) were current or previous smokers. Over all 10/54(24.1%) developed shock, 10/54(18.5%) had pulmonary oedema and congestive heart failure, 6/54(11.1%) developed arrhythmia, 6/54(11.1%) died in the hospital, and 2/54(3.7%) had ventricular wall aneurysm formation. 1/54(1.9%) had stroke, re infarction and thrombus formation. No patient developed pericarditis and LV dysfunction. Conclusion Majority of patients admitted with myocardial infarction had STEMI and present with chest pain. Most patients are males. Hypertension, Diabetes Mellitus and dyslipidaemia were high risk factors. There was delayed time to presentation to hospital from the time of onset of symptoms. Almost half of the patients with STEMI developed pulmonary edema, shock, congestive heart failure and arrhythmia.