H. M. Alexander

How soon after quitting smoking does risk of heart attack decline

A population-based case-control study (involving 1282 cases and 2068 controls) was conducted to examine the risk of myocardial infarction or coronary death after cigarette smokers quit smoking. The odds ratios for current smokers were significantly elevated compared to non-smokers (OR = 2.7 for men and OR = 4.7 for women). For ex-smokers odds ratios declined rapidly after quitting and after about 3 years they were not significantly different from unity. Fibrinogen concentrations measured in the controls only were higher in current smokers and ex-smokers up to 2 years after quitting than in non-smokers and after that time were similar to levels in non-smokers; however, most of the differences among categories of smokers were not statistically significant. These results support the hypothesis that risk of a coronary event in ex-smokers declines rapidly after quitting and within 2-3 years is similar to the risk for non-smokers.

Success of cardiopulmonary resuscitation after heart attack in hospital and outside hospital.

Abstract Objectives: To determine factors associated with cardiopulmonary resuscitation being attempted after cardiac arrest from myocardial infarction, in or outside hospital, and estimate short term and long term survival rates. Design: Descriptive cross sectional and cohort study. Setting: Community based register of all suspected heart attacks and sudden cardiac deaths in Lower Hunter region of New South Wales, Australia. Subjects: 4924 men and women aged 25-69. Main outcome measures: Rates of attempted cardiopulmonary resuscitation and survival after successful resuscitation. Results: Cardiopulmonary resuscitation was attempted in 41% of cases of cardiac arrest after myocardial infarction outside hospital and 63% of cases in hospital. Survival rates at 28 days were 12% and 39% respectively. Among the survivors, although 41% had another myocardial infarction (or coronary death), 81% of both groups were still alive two years later. Younger and better educated people were more likely to receive cardiopulmonary resuscitation in either setting, and being married predicted cardiopulmonary resuscitation being attempted outside hospital. Younger age predicted better survival rates after attempted resuscitation in hospital. Conclusions: The reasons for better education to predict cardiopulmonary resuscitation being attempted need explanation. The higher survival rate after cardiopulmonary resuscitation in hospital compared with outside hospital and the good long term prognosis for survivors in both settings suggest that attempts to improve success of cardiopulmonary resuscitation outside hospital may be worth while.

Risk of primary and recurrent acute myocardial infarction from lipoprotein(a) in men and women.

OBJECTIVES This study sought to examine whether lipoprotein(a) concentrations were risk factors for a first acute and recurrent myocardial infarction. BACKGROUND There is conflicting evidence concerning the risk of acute myocardial infarction from lipoprotein(a). No studies have examined the risk of recurrent acute myocardial infarction from lipoprotein(a), and few have addressed the risk in women. METHODS This was a population-based case-control study of 893 men and women 35 to 69 years old participating in the World Health Organization Monitoring Trends and Determinants in Cardiovascular Disease (MONICA) Project in Newcastle, Australia in 1993 to 1994. Case and control patients were classified into those with and without a previous myocardial infarction, and median lipoprotein(a) concentrations were compared after adjusting for other variables. Quintiles of lipoprotein(a) concentration were also examined. RESULTS Compared with control subjects without a previous myocardial infarction, median lipoprotein(a) concentrations increased from case patients with a first myocardial infarction (15 mg/liter higher, 95% confidence interval [CI] -36 to 60) to control patients with a previous myocardial infarction (159 mg/ liter higher, 95% CI 40 to 278) and case patients with a previous myocardial infarction (60 mg/liter higher, 95% CI -16 to 136, p < 0.01, test for trend). Women had significantly higher lipoprotein(a) concentrations than men (median 71 mg/liter higher, 95% CI 23 to 118). The highest quintile of lipoprotein(a) (>550 mg/liter) was a significant risk factor for a first acute myocardial infarction (odds ratio [OR] 1.77, 95% CI 1.03 to 3.03); but in those with a previous myocardial infarction, the highest quintile was not associated with recurrent myocardial infarction (OR 0.84, 95% CI 0.30 to 2.37). CONCLUSIONS High lipoprotein(a) concentrations may be a marker of vascular or tissue injury or may be associated with other genetic or environmental factors that cause acute myocardial infarction. Currently, lipoprotein(a) measurement cannot be recommended for assessment of risk for acute myocardial infarction.

Changing patterns of coronary heart disease in the Hunter Region of New South Wales, Australia

A population-based observational study of men and women aged 35-69 years in the Hunter Region of New South Wales, Australia, was conducted to assess the impact of risk-factor modification and increased drug therapy on the trends in major coronary events and case fatality. From 1985 to 1993, there were 3006 coronary deaths and 6450 nonfatal major coronary events. Rates of death and nonfatal myocardial infarction declined, but there was an increase in hospital admissions for prolonged chest pain. Reductions in cigarette smoking, diastolic blood pressure, total cholesterol, and increased use of aspirin can fully explain the 3.3% (95% confidence interval [CI] 2.4, 4.2) average annual reduction in rates of major coronary events for men and the 4.1% (95% CI 2.7, 5.5) reduction for women. In contrast, increased use of aspirin, beta-blockers, fibrinolytic therapy, and angiotensin-converting enzyme inhibitors explain less than half of the 8.9% (95% CI 5.9, 11.8) and 6.9% (95% CI 2.7, 10.9) average annual reduction in case fatality in hospital for men and women, respectively. These trends suggest a decline in severity of coronary heart disease consistent with reductions in risk-factor levels and improved acute medical treatment.

Whose diet has changed

Abstract: The same questions about diet were asked in two community–based surveys conducted in the Hunter Region of New South Wales in 1983 and 1994. There were substantial changes in diet over the period; for example, the proportion of respondents who reported using low–fat or skim milk increased from 25 per cent to 51 per cent, the proportion eating meat fewer than five times a week doubled from 21 per cent to 42 per cent and the proportion eating fewer than three eggs per week increased from 55 per cent to 80 per cent. In both surveys, women reported eating a healthier diet than men, and older people and those of higher socioeconomic status reported better diets than younger people or people with less education or lower status occupations. The surprising finding was that over the 11–year period the changes in patterns of food consumption were remarkably similar across all strata of the population. The conclusions are that widespread dietary change is possible. However, the changes in the last decade related mainly to reducing the risk of cardiovascular disease; similar behavioural changes to reduce the risk of diet–related cancer are required.