Sudden cardiac death in diabetes mellitus: risk factors in the Rochester diabetic neuropathy study.

OBJECTIVES: To determine risk factors for sudden cardiac death and the role of diabetic autonomic neuropathy (DAN) in the Rochester diabetic neuropathy study (RDNS). METHODS: Associations between diabetic and cardiovascular complications, including DAN, and the risk of sudden cardiac death were studied among 462 diabetic patients (151 type 1) enrolled in the RDNS. Medical records, death certificates, and necropsy reports were assessed for causes of sudden cardiac death. RESULTS: 21 cases of sudden cardiac death were identified over 15 years of follow up. In bivariate analysis of risk covariates, the following were significant: ECG 1 (evolving and previous myocardial infarctions): hazard ratio (HR) = 4.4 (95% confidence interval (CI), 1.6 to 12.1), p = 0.004; ECG 2 (bundle branch block or pacing): HR = 8.6 (2.9 to 25.4), p<0.001; ECG 1 or ECG 2: HR = 4.2 (1.3 to 13.4), p = 0.014; and nephropathy stage: HR = 2.1 (1.3 to 3.4), p = 0.002. Adjusting for ECG 1 or ECG 2, autonomic scores, QTc interval, high density lipoprotein (HDL) cholesterol, 24 hour microalbuminuria, and 24 hour total proteinuria were significant. However, adjusting for nephropathy, none of the autonomic indices, QTc interval, HDL cholesterol, microalbuminuria, or total proteinuria was significant. At necropsy, all patients with sudden cardiac death had coronary artery or myocardial disease. CONCLUSIONS: Sudden cardiac death was correlated with atherosclerotic heart disease and nephropathy, and to a lesser degree with DAN and HDL cholesterol. Although DAN is associated with sudden cardiac death, it is unlikely to be its primary cause.

Variation in clinical preventive services.

CONTEXT: Preventive services are not delivered at optimal rates in primary care settings, and the literature suggests that a systems approach is key to improvement. Studying variation among clinics could help us to understand the extent of system use in practice. PRACTICE PATTERN EXAMINED: The proportion of patients who are up-to-date for preventive services in 44 primary care practices in the Midwest. PREVENTIVE SERVICES EXAMINED: Papanicolaou (Pap) smear, cholesterol testing, mammography, clinical breast examination, blood pressure measurement, influenza and pneumococcal vaccinations, and advice on tobacco use. DATA SOURCE: 6830 patients surveyed after their clinic visit (response rate, 85%). RESULTS: The proportion of patients up-to-date for preventive services varied widely among clinics. For example, up-to-date rates for Pap smear testing ranged from 70% to 93% and 45% to 88% for cholesterol screening. There was little correlation between a clinic's performance on one preventive service (relative to the other 43 clinics) and its performance on others. When correlations between pairs of up-to-date rates within clinics were examined, only 4 of 28 service pairs were positive and statistically significant and only 1 had a correlation coefficient that exceeded 0.5 (for mammography and clinical breast examination). CONCLUSION: There is wide variation in the rates at which various preventive services are performed, both between and within clinics. This variation, which is probably due to a lack of organized prevention systems that cover multiple services, provides a clear target for improvement efforts.

Time trends in the prevalence of atherosclerosis: a population-based autopsy study.

PURPOSE: Mortality from coronary heart disease is declining but little is known about trends in the prevalence of atherosclerosis. Autopsy rates in Olmsted County, Minnesota, are higher than the national average, offering an opportunity to address this matter. In this study, we determined the prevalence of anatomic coronary disease among autopsied Olmsted County residents and examined the generalizability of these findings. SUBJECTS AND METHODS: Reports of the 2,562 autopsies performed between 1979 and 1994 on Olmsted County residents > or =20 years of age were reviewed for the presence of coronary disease. RESULTS: Among autopsied decedents less than 60 years old at death and among coroner's cases, the prevalence of anatomic coronary disease declined with time (P for trend = 0.05); no trend was detected among older persons or noncoroner's cases. By logistic regression analysis, the crude odds ratio ([OR] per 5 years) for the association between time and anatomic coronary disease was 0.94 (95% confidence interval [CI]: 0.86 to 1.03; P = 0.18]. Age, sex, and antemortem diagnosis of heart disease were also strongly related to the presence of disease. After adjustment for sex and antemortem diagnosis of heart disease, the prevalence of anatomic coronary disease decreased more in younger people than in older people (age 40 years: OR 0.43 [95% CI: 0.24 to 0.80]; age 60 years: OR 0.62 [95% CI: 0.45 to 0.87]; age 80 years: OR 0.89 [95% CI: 0.64 to 1.23]). CONCLUSION: The prevalence of anatomic coronary disease at autopsy decreased between 1979 and 1994, particularly among younger people, supporting the notion that the burden of coronary disease has shifted toward the elderly. These results suggest that the decreased incidence of coronary artery disease has contributed to the recent decrease in coronary mortality, particularly among younger people.

Number needed to treat: caveat emptor.

Number needed to treat (NNT)-the inverse of the absolute risk reduction resulting from an intervention-was introduced as a yardstick to describe the harm as well as the benefit of therapeutic maneuvers. Analysis using NNT works well when comparing two or more interventions that have their impact over the same period of time in similar populations or patients. Under other conditions, however, analysis based on NNT can produce results that diverge widely from the impact that the interventions can be expected to have on risk of death. This can happen either for entire populations or for an individual when comparing NNTs for interventions which have their effects on different subsets of the population or when comparing interventions which have their effects over different periods of time. We demonstrate how this can occur by comparing the NNTs and effect of intervention on deaths in a population for automatic implantable cardioverter defibrillators (AICDs), heart transplantation, and cholesterol lowering through nutritional intervention with plant stanol ester.

Attitudes of Olmsted County, Minnesota, residents about tobacco smoke in restaurants and bars.

OBJECTIVE: To determine the attitudes of Olmsted County, Minnesota, adults about environmental tobacco smoke in restaurants, bars, and nightclubs. SUBJECTS AND METHODS: In this population survey,2014 adults were contacted by random digit dial methods between February 28 and May 5, 2000, and asked to participate in a telephone survey; 1224 (61%) consented. RESULTS: For the 57% (95% confidence interval [CI], 54%-60%) of the study population that reported exposure to environmental tobacco smoke, the most frequently reported sites of exposure were restaurants (44% [95% CI, 41%-48%]), work (21% [95% CI, 18%-24%]), and bars (19% [95% CI, 16%-22%]). Seventy-two percent (95% CI, 69%-74%) of respondents said that they would select a smoke-free restaurant over one where smoking is permitted, and 70% (95% CI, 67%-72%) said that they would select a smoke-free bar over one where smoking is permitted. The majority of respondents said that they would not dine out or visit bars or nightclubs more often or less often if all restaurants, bars, and nightclubs were smoke-free. CONCLUSIONS: Olmsted County residents prefer smoke-free restaurants, bars, and nightclubs.

Preventing heart disease and stroke: messages from the United States.

After rising steeply in the United States for the first two-thirds of the century, mortality from cardiovascular disease in the United States has declined sharply in the past 40 years. In addition to advances in the treatment of clinically manifest cardiovascular disease, the decline in deaths from cardiovascular disease results from a decline in tobacco consumption, decreased serum cholesterol levels, and improved control of hypertension. However, recent changes in risk factor levels are a cause for concern. These changes include sharp increases in smoking among young adults; increases in obesity and type II diabetes; a decrease in physical activity; and, a decline in hypertension control. In order to reduce the burden of cardiovascular disease in Olmsted County, Minnesota, we organized CardioVision 2020 (www.cardiovision2020.org). CardioVision 2020 is a population-based, multi-faceted, collaborative project based on personal commitment and community action.

The ability of a computer program based on the Marquette Matrix-12 short measurement matrix to replicate coding by the Minnesota ECG coding laboratory.

The study was undertaken to determine whether a computer program that uses "short measurement matrix" data from the Marquette Matrix-12 system can replicate Minnesota electrocardiogram (ECG) coding laboratory interpretations. An agreement was found between coding of median complex ECGs at the Minnesota ECG coding laboratory and coding based on Marquette Matrix-12 short measurement matrix. The comparison was based on 763 ECGs plus chest pain history and serum enzyme values for a stratified random sample of 141 patients hospitalized in 1990 or 1991 for an event coded as HICDA 410.x (acute myocardial infarction), 411 (other acute and subacute forms of ischemic heart disease), 413 (angina pectoris), or 796.9 (other ill defined and unknown causes of morbidity and mortality). The population was reconstructed from the stratified random sample to enable population-based inferences. Exact agreement between Matrix-12 and Minnesota coding laboratory interpretation on 4 ECG patterns (evolving diagnostic, diagnostic, equivocal, or other ECG pattern) was 74.5% (Kappa = 0.63 +/- 0.05) for the stratified random sample and 78.8% (Kappa = 0.66 +/- 0.05) for the reconstructed population. For coding myocardial infarction based on the ECG, serum enzyme levels, and ischemic chest pain, agreement was 91.5% (Kappa = 0.85 +/- 0.04) for the stratified random sample and 90% (Kappa = 0.83 +/- 0.04) for the reconstructed population. Although ECG interpretation by a computer program based on the short measurement matrix of the Matrix 12 system results in better agreement than prior attempts to replicate the Minnesota coding laboratory, interpretation remains unacceptably discordant.

The CardioVision 2020 baseline community report card.

OBJECTIVE: To establish baseline data for the CardioVision 2020 program, a collaborative project in Olmsted County, Minnesota, organized to reduce cardiovascular disease rates by altering 5 health-related items: (1) eliminating tobacco use and exposure, (2) improving nutrition, (3) increasing physical activity, (4) lowering serum cholesterol level, and (5) controlling blood pressure. SUBJECTS AND METHODS: Data about tobacco use, diet, and physical activity were collected by random digit dial interview and follow-up questionnaire from a sample of the population. Blood pressure data were collected from medical records at Mayo Clinic, and serum cholesterol data were derived from the Mayo Clinic laboratory database. Data were stratified into 6 age groups. RESULTS: A total of 624 women and 608 men responded to the questionnaire. Population blood pressure data were available for 1,956 women and 1,084 men. Population serum cholesterol data were available for 17,042 women and 12,511 men. Except for women in the 30- to 39-year-old age group, less than 10% of the population sampled met 4 or 5 goals. Conversely, about 90% of the population met at least 1 goal, and about 80% met 1, 2, or 3 of the goals. CONCLUSION: The data from the Olmsted County population indicate considerable opportunity to reduce this population's burden of cardiovascular disease.

Validation of death certificate diagnosis of out-of-hospital coronary heart disease deaths in Olmsted County, Minnesota.

OBJECTIVE: To evaluate the validity of death certificate diagnosis of out-of-hospital (OOH) coronary heart disease (CHD) and sudden cardiac death (SCD) in Olmsted County, Minnesota, between 1981 and 1994. METHODS: In this review of the medical records, autopsy reports, and coroner's files, OOH deaths with heart disease as the underlying cause of death on the death certificate were classified into CHD (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] codes 410-414) and non-CHD (other ICD-9-CM heart disease codes) deaths. A 10% random sample (n = 174) of these death certificates was reviewed by physicians, and published validation criteria were applied to classify these deaths into validated CHD or non-CHD categories. Sudden cardiac death was defined as validated CHD that occurred at an OOH location with less than 24 hours between symptom onset and death. RESULTS: The death certificate definition of OOH CHD death (ICD-9-CM codes 410-414) had high sensitivity and positive predictive value of 91% and 96%, respectively. The specificity and the negative predictive value were slightly lower at 86% and 72%, respectively. The sensitivity of death certificate diagnosis of CHD for validated SCD was 89%, and the positive predictive value was 77%. Using a more restrictive definition of SCD, that is, less than 1 hour between the onset of symptoms and death, the positive predictive value of CHD codes for SCD was lower at 52%. CONCLUSIONS: In Olmsted County, the positive predictive values of death certificate diagnosis for OOH CHD and SCD are high. Relying on death certificate diagnoses results in about 5% underestimation of the true CHD rates, whereas their use as a surrogate for SCD yields a 16% overestimation of the true SCD rates.