History Of Recent Myocardial Infarction Research Articles

Are preventive drugs preventive enough? A study of patients’ expectation of benefit from preventive drugs

Objectives - The study aimed to find the threshold of benefit for a hypothetical cholesterol-lowering drug below which the subject would not be prepared to take the drug. We also looked at whether proximity to the target event (myocardial infarction) and the subjects’ views on drug taking affected this threshold.Design - We studied 307 subjects using a written questionnaire and interview. Group 1 (102 subjects) had just been discharged from the coronary care unit. Group 2 (105 subjects) were taking cardio-protective drugs but had no recent history of myocardial infarction. Group 3 (100 subjects) had no history of myocardial infarction and were taking no cardio-protective drugs.Results - Median values for the threshold of benefit below which the subject would not take the preventive drug were 20%, 20%, and 30% absolute risk reduction for Groups 1, 2 and 3 respectively. Median values for expectation of average prolongation of life were 12, 12 and 18 months respectively. Only 27% of subjects would take a drug offering 5% or less absolute risk reduction over five years. Subjects’ views on medicinal drug taking in general and proximity to the target event were predictors of the acceptance of preventive drugs. Eighty percent of subjects wished to be told the numerical benefit of a preventive drug before starting on it.Conclusion - For the majority, the expectation of benefit from a preventive drug is higher than the actual benefit provided by current drug strategies. There is a tension between the patient’s right to know about the chance of benefiting from a preventive drug and the likely reduction in uptake if they are so informed.

Predictors for waiting time for coronary angioplasty in a high risk population.

Objective--To describe the clinical and non-clinical factors which influence the waiting time from initial angiography to angioplasty. Design--Follow up of a random sample of 106 patients undergoing their first coronary angiography for whom a decision to revascularise by percutaneous transluminal angioplasty was made in 1991. The period between the date of angiography and the date of angioplasty and various clinical characteristics of patients were retrieved from medical notes in mid 1993. Patients were sampled from those investigated in the two Northern Ireland catheterisation laboratories in Belfast, which provide services for the whole of the province (population 1.5 million). Main measures--The dependent variable was the period between initial angiography and angioplasty, and the independent variables included age, sex, distance from cardiac catheterisation centre, referral source, characteristics of the clinical history, severity of angina, and anatomical extent of disease. Cox's proportional hazards analysis was used to derive a relative hazard, expressing the relative chances of revascularisation occurring at any time during follow up. Results--Of the 106 patients studied, 93 had had percutaneous transluminal angioplasty at follow up. The most important predictors of waiting time were the presence of severe angina (relative hazards 3.1(95 % confidence interval (95% CI) 1.4-6.8) and 2.7(1.2-6.2) for Canadian Cardiovascular grades III and IV v angina grade I angina), a recent history of myocardial infarction (relative hazard, 2.5(1.3-4.8), and whether or not the patient was economically active (relative hazard 0.6(0.4-1.0) for economically inactive v active patients). Although there was also an association with the relative deprivation of the area of residence of the patient it had no clear linear trend. Conclusions--Although waiting time for percutaneous transluminal angioplasty was predictably related to the patient's clinical presentation, demographic factors may also be important in determining access to intervention. These factors clearly merit further study; ultimately, the evaluation of equity in a waiting time distribution may more properly be a societal rather than a clinical judgment.

Angiographic predictors of new coronary occlusions

To determine whether coronary angiography is predictive of the future site of coronary occlusion, we analyzed the coronary angiograms of 246 consecutive patients having two or more angiograms with therapeutic invasive intervention in the interval between angiograms. The average interval between studies was 46 months. Of 2183 normal segments at the first angiogram, 51 (2.3%) were occluded at the second angiogram, whereas in segments with minimal disease (1% to 25% diameter stenosis) 33 (8%) of 411 were occluded ( p < 0.05). There was a further stepwise increase in the occlusion ratio, with increasing stenosis reaching a 31% occlusion ratio in lesions with critical (91% to 99%) stenosis at the first angiogram. For any given degree of stenosis, the occlusion ratio of “long” lesions (5 to 20 mm) was on the average more than twice that of “short” lesions (<5 mm, p < 0.01), except in lesions with critical stenosis (91% to 99%) where length was no longer important. Occlusion of segments judged free of disease on the first angiogram was highest in the right coronary artery, 4.7%, versus 2.7% in the left anterior descending and 0.6% in the circumflex artery ( p < 0.01). History of recent myocardial infarction was a good clinical predictor of occlusion and deterioration of ventricular function.

Diffuse Embolization Following Percutaneous Transluminal Coronary Angioplasty of Occluded Vein Grafts: The Blush Phenomenon

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 146 saphenous vein grafts in 116 patients. In 29 patients, 31 grafts were totally occluded. Myocardial staining lasting over 5 minutes--"the blush phenomenon"--followed the opening of the occluded grafts in 9 of these patients. In 5 of these 9, enzyme release suggested infarction. A sixth patient died within a few hours of PTCA, with suspected infarction. Autopsy demonstrated diffuse and extensive distal coronary arterial embolization of grumous material, including cholesterol crystals, platelets, and fibrin. The blush phenomenon was not seen following PTCA in the remaining 20 patients with total occlusions, nor in any of the 87 patients with stenosed grafts. We have not observed the blush phenomenon following PTCA of more than 3300 coronary arteries. Of the 9 patients demonstrating the blush phenomenon, 6 had a recent history of myocardial infarction or unstable angina pectoris, compared with 4 of the remaining 20 patients with occluded grafts. We now approach occluded grafts with injection of intragraft thrombolytic agents or with atherectomy prior to PTCA. Future approaches may include atherectomy or laser angioplasty.

Are patients with a history of recent myocardial infarction at higher risk for complications during coronary bypass surgery?

Are patients with a history of recent myocardial infarction at higher risk for complications during coronary bypass surgery?

The use of epinephrine in the treatment of older adult asthmatics.

Three subcutaneous doses of 0.3 mL 1:1,000 epinephrine were given 20 minutes apart to 95 adult asthmatics 15 to 96 years old during 108 asthma exacerbations. Patients with a history of recent myocardial infarction or of angina were excluded from our study. Heart rhythm and rate, blood pressure, respiratory rate, and clinical response were prospectively evaluated before, during, and after the administration of epinephrine. There was no significant difference in the occurrence of ventricular arrhythmias between patients less than 40 and more than 40 years old. The mean systolic and diastolic blood pressures, mean heart rate, and mean respiratory rate decreased with treatment in the older population. Our results suggest that epinephrine is safe to use in acute asthmatics of any age.

Deep-Vein Thrombosis Mimicking Acute Appendicitis

IN THE very young and the elderly, acute appendicitis commonly has an atypical presentation and a high perforation rate.¹It represents a difficult clinical challenge. The surgical and nonsurgical conditions that mimic acute appendicitis are well known.²The overall rate of a normal appendix at appendectomy is 20%, and the rate is much higher in women.¹In highrisk patients, particularly those with a history of recent myocardial infarction or other serious illnesses, a correct preoperative diagnosis is of the utmost importance because unnecessary surgery carries with it a substantial morbidity and mortality for these patients. Recent literature has incriminated the Swan-Ganz catheter and other invasive intravascular devices in the development of venous or arterial thrombosis. Ileofemoral venous thrombosis can mimic the symptoms of acute appendicitis, and it should be included in the differential diagnosis of right lower quadrant abdominal pain. A complete history and careful physical examination

Application and safety of outpatient ergonovine testing in accurately detecting coronary spasm in patients with possible variant angina

We analyzed the results of 61 consecutive outpatient ergonovine provocation tests to determine the safety and efficacy of such outpatient testing for detecting coronary artery spasm (CAS). Criteria for outpatient testing included: clinical history suggestive of variant angina, noncritical coronary artery disease documented by coronary arteriography, normal exercise treadmill test, no symptomatic arrhythmias, and no history of recent myocardial infarction. All antianginal medications were tapered and stopped. Ergonovine maleate was given as a bolus at 3-minute intervals in consecutive doses of 0.05, 0.10, and 0.25 mg. A positive test was defined as chest pain accompanied by > 0.1 mV ST segment elevation on 12-lead ECG. If pain and ST-segment elevation occurred, intravenous and sublingual nitroglycerin were immediately administered for rellef of myocardial ischemia. Of the 61 patients studied, 10 had positive tests; there were no complications. Follow-up of the 51 patients with negative studies has not revealed cardiac etiology for their chest pain. We conclude that outpatient ergonovine testing is a safe and accurate diagnostic test for identifying CAS in a highly selected population of patients with possible variant angina when performed under carefully controlled conditions.