Doctors' opinions on the prevention of myocardial infarction

In 1979, 1981 and 1983 random samples of approximately 200 general practitioners, 200 members of the Royal College of General Practitioners and 200 hospital physicians were asked to list, in order of effectiveness, measures which they considered useful in the prevention of myocardial infarction and reinfarction. The overall response rate was 67% and of the responses 77% were eligible for inclusion in the analysis.

There was a high degree of concordance between the opinions of the nine doctor-year groups (Kendall's W = 0.89, P < 0.001). Behavioural measures, such as diet, weight control, exercise and cessation of smoking, were mentioned frequently and were ranked above most drug therapies. Overall, opinions concerning the relative utility of different measures did not change between 1979 and 1983 yet there were significant changes in the frequency with which specific therapies were mentioned as useful preventive measures. Beta-blockers, calcium channel blockers, and arteriograms/coronary artery bypass grafting were mentioned more frequently in 1983 than in 1979 while lowering the lipid levels (with drugs) and sulphinpyrazone were mentioned less frequently. The changes in the opinions of doctors are discussed in the context of new therapeutic information published between 1979 and 1983.

     

The pathogenesis of angina pectoris and myocardial infarction.

A number of observations that have accumulated in the literature in the past several years cannot be explained by the classic pathogenetic hypothesis of angina pectoris and myocardial infarction. Experimental cardiac necroses of metabolic origin can be easily produced in the animal and if the classic pathogenetic hypothesis of angina pectoris and myocardial infarction is modified to include a metabolic factor, most of the unexplained observations become explainable.     

The incidence of myocardial infarction

I studied 183 patients with myocardial infarction including sudden deaths related to ischaemic heart disease occurring in general practice during a period of four years.

The figures are examined by age, sex, history of event, and place of treatment. The ratio of male to female infarctions was 2:1, males having a mean age of 63 years and females 71 years.

The total death rate for all myocardial infarctions was 46 per cent, but if sudden deaths are excluded, the rate becomes 24 per cent.

The annual incidence of myocardial infarction per 1,000 in the practice population of 11,195 was 4.1 and the total annual death rate per 1,000 was 1.9.

     

Long-term benefit of primary angioplasty as compared with thrombolytic therapy for acute myocardial infarction.

BACKGROUND: As compared with thrombolytic therapy, primary coronary angioplasty results in a higher rate of patency of the infarct-related coronary artery, lower rates of stroke and reinfarction, and higher in-hospital or 30-day survival rates. However, the comparative long-term efficacy of these two approaches has not been carefully studied. METHODS: We randomly assigned a total of 395 patients with acute myocardial infarction to treatment with angioplasty or intravenous streptokinase. Clinical information was collected for a mean (+/-SD) of 5+/-2 years, and medical charges associated with the two treatments were compared. RESULTS: A total of 194 patients were assigned to undergo primary angioplasty, and 201 to receive streptokinase. Mortality was 13 percent in the angioplasty group, as compared with 24 percent in the streptokinase group (relative risk, 0.54; 95 percent confidence interval, 0.36 to 0.87). Nonfatal reinfarction occurred in 6 percent and 22 percent of the two groups, respectively (relative risk, 0.27; 95 percent confidence interval, 0.15 to 0.52). The combined incidence of death and nonfatal reinfarction was also lower among patients assigned to angioplasty than among those assigned to streptokinase, with a relative risk of 0.13 (95 percent confidence interval, 0.05 to 0.37) for early events (within the first 30 days) and a relative risk of 0.62 (95 percent confidence interval, 0.43 to 0.91) for late events (after 30 days). The rates of readmission for heart failure and ischemia were also lower among patients in the angioplasty group than among patients in the streptokinase group. Total medical charges per patient were lower in the angioplasty group (16,090 dollars) than in the streptokinase group (16,813 dollars, P=0.05). CONCLUSIONS: During five years of follow-up, primary coronary angioplasty for acute myocardial infarction was associated with lower rates of early and late death and nonfatal reinfarction, fewer hospital readmissions for ischemia or heart failure, and lower total medical charges than treatment with intravenous streptokinase.     

The impact of initial treatment delay using primary angioplasty on mortality among patients with acute myocardial infarction: from the Korea acute myocardial infarction registry

The impact of treatment delays to reperfusion on patient mortality after primary percutaneous coronary intervention (PCI) for ST elevation myocardial infarction (STEMI) is controversial. We analyzed 5,069 patients included in the Korea Acute Myocardial Infarction Registry (KAMIR) between November 2005 and January 2007. We selected 1,416 patients who presented within 12 hr of symptom onset and who were treated with primary PCI. The overall mortality at one month was 4.4%. The medians of door-to-balloon time, symptom onset-to-balloon time, and symptom onset-to-door time were 90 (interquartile range, 65-136), 274 (185-442), and 163 min (90-285), respectively. One-month mortality was not increased significantly with any increasing delay in door-to-balloon time (4.3% for < or =90 min, 4.4% for >90 min; p=0.94), symptom onset-to-balloon time (3.9% for < or =240 min, 4.8% for >240 min; p=0.41), and symptom onset-to-door time (3.3% for < or =120 min, 5.0% for >120 min; p=0.13). These time variables had no impact on one-month mortality in any subgroup. Thus, this first nationwide registry data in Korea showed a good result of primary PCI, and the patient prognosis may not depend on the initial treatment delay using the current protocols.     

Thrombolytic therapy and myocardial infarction.

Examination of 27 hearts from patients treated by streptokinase following myocardial infarction showed one major histopathological difference from controls, the presence of massive interstitial haemorrhage into the necrotic tissue in some cases. This change is presumably related to the re-establishment of the circulation to infarcted areas.