Report into a discordant result at D16S539 between SGM Plus® and PowerPlex® ESI 16 kits in a criminal case sample and implications for the UK National DNA Database upgrade.

Upon re-testing of a DNA extract as part of a defence examination, a discordant result was observed at D16S539. Further STR testing and DNA sequencing of the sample identified the cause as a primer binding site mutation which was shown to be a previously unreported SNP. The testing results obtained in this case are considered in light of the current ongoing Multiplex Upgrade Project in the UK and the likely increase in discordant results that may be observed once different next generation kits are introduced.

Y chromosome STR haplotype data for an Irish population.

Y chromosome haplotype data was collected for 155 Irish males residing in the Republic of Ireland. Eleven short tandem repeat (STR) markers: DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439 were analysed and the allele and haplotype frequencies calculated. This Irish data is presented here and was found to be less diverse when compared with the neighbouring UK population.

Epidemiology of persistent proteinuria in type II diabetes mellitus. Population-based study in Rochester, Minnesota.

Clinical risk factors for nephropathy were assessed in a population-based study of Rochester, Minnesota, residents with diabetes mellitus initially diagnosed between 1945 and 1969 (incidence cohort). The 1031 Rochester residents with non-insulin-dependent diabetes mellitus (NIDDM) were followed through their complete medical records in the community to 1 January 1982. The prevalence of persistent proteinuria was 8.2% at the diagnosis of NIDDM. Among those initially free of persistent proteinuria, the subsequent incidence was 15.3/1000 person-yr. Twenty years after the diagnosis of diabetes, the cumulative incidence of persistent proteinuria was 24.6%. A proportional hazards model identified the following risk factors for persistent proteinuria in NIDDM: elevated initial fasting blood glucose (P less than .01); older age at onset of diabetes (P less than .01); male gender (P = .05); and presence of macrovascular disease (P = .05), diabetic retinopathy (P = .05), or glycosuria (P = .07) at the diagnosis of diabetes. Separate analyses controlling for attained age indicated no association between duration of NIDDM and the incidence of persistent proteinuria. Stratified analysis of the two most significant risk factors (fasting blood glucose and age) indicated that hyperglycemia was a stronger risk factor for proteinuria in younger diabetic subjects, perhaps because of a competing risk of death in the elderly diabetic patient. In contrast to a recently described decreasing secular trend of proteinuria in Danish insulin-dependent diabetes mellitus patients, there was no decrease over the past 40 yr in proteinuria risk in this NIDDM incidence cohort.

Evaluation and management of patients with both peripheral vascular and coronary artery disease.

The prevalence of serious angiographic coronary artery disease ranges from 37% to 78% in patients undergoing operation for peripheral vascular disease. Clinical studies have demonstrated that cardiac outcome after peripheral vascular surgery is not adequately predicted by the standard criteria of history, physical findings and rest electrocardiogram. An adequate exercise work load, left ventricular function and thallium redistribution have proved important in perioperative risk stratification. The choice of a perioperative functional cardiac test depends on patient-related factors and the nature of the peripheral vascular operation. Although procedures involving aortic cross-clamping exert a greater hemodynamic stress than do carotid endarterectomy and femoral popliteal surgery, late cardiac morbidity and mortality are significant in all patients with atherosclerotic disease. The decision to proceed with preoperative coronary angiography and myocardial revascularization should be based primarily on indications independent of the peripheral vascular procedure. However, peripheral vascular surgery may influence the timing of myocardial revascularization. Patients with high risk or unstable coronary artery disease may benefit from preoperative coronary revascularization, although this hypothesis remains unproved. In all patients, careful monitoring during and after operation is essential. All patients with peripheral vascular disease should be considered to be at lifelong risk for fatal and nonfatal cardiac events and should undergo appropriate clinical and laboratory evaluation and be treated accordingly.

Natural history of idiopathic dilated cardiomyopathy: effect of referral bias and secular trend.

OBJECTIVES: The current study was designed to determine the effect of secular trend and referral bias on the natural history of idiopathic dilated cardiomyopathy. BACKGROUND: In a previous study of 104 patients with idiopathic dilated cardiomyopathy conducted in a referral population at the Mayo Clinic between 1960 and 1973, the 1- and 5-year mortality rates were 31% and 64%, respectively. A recent study of 40 patients with idiopathic dilated cardiomyopathy conducted in a population-based cohort at the Mayo Clinic between 1975 and 1984 reported 1- and 5-year mortality rates of 5% and 20%, respectively. We hypothesized that improvements in diagnosis and therapy have occurred since the original referral cohort was described and that these improvements have altered the apparent natural history of the disease. We refer to this effect as secular trend. Alternatively, the presence of more advanced disease in the referral population (referral bias) may also contribute to the differences in survival. METHODS: Two sequential referral populations with idiopathic dilated cardiomyopathy seen at the Mayo Clinic between 1976 and 81 (n = 85) and 1982 and 1987 (n = 137) were identified. Outcome was compared between these cohorts and the 1960-1973 referral cohort to examine the effect of secular trend. Outcomes were compared with that of the population-based cohort to examine the effect of referral bias. RESULTS: Survival in the 1976-1981 referral cohort did not differ from that in the 1960-1973 referral cohort, suggesting little impact of secular trend during these time periods. Survival in the more recent 1982-1987 referral cohort was significantly better than that in the earlier referral cohorts, suggesting that improvements in diagnosis and treatment in the 1980s altered the natural history of idiopathic dilated cardiomyopathy. Survival in the 1982-1987 referral cohort was still worse than that of the population-based cohort, suggesting an effect of referral bias on studies of the natural history of idiopathic dilated cardiomyopathy. CONCLUSIONS: The current study demonstrates that secular trend and referral bias affect the apparent natural history of idiopathic dilated cardiomyopathy. Survival in referral patients with this disease is significantly better than previously described.

Influence of coronary artery disease on morbidity and mortality after abdominal aortic aneurysmectomy: a population-based study, 1971-1987.

The prognostic importance of coronary artery disease at the time of elective abdominal aortic aneurysmectomy was evaluated among 131 residents of Olmsted County, Minnesota who underwent elective aneurysmectomy from 1971 to 1987 and were followed up to 1988 for death and cardiac events (cardiac death, myocardial infarction, coronary bypass surgery and angioplasty). Before aneurysmectomy, 75 patients (Group 1) had no clinically recognized coronary disease, 47 patients (Group 2) had suspected or overt uncorrected coronary artery disease (history of prior myocardial infarction, angina or a positive stress test) and 9 patients (Group 3) had undergone coronary artery bypass grafting or coronary angioplasty. The 30 day operative mortality rate was 3% (2 of 75) in Group 1 and 9% (4 of 47) in Group 2 (p = 0.15). According to Kaplan-Meier analysis, estimated survival 8 years after aneurysmectomy was 59% (expected rate 68%, p = 0.29) in Group 1 versus 34% (expected rate 61%, p = 0.01) in Group 2. The cumulative incidence rate of cardiac events at 8 years was 15% and 61%, respectively, for patients without and with suspected/overt coronary artery disease (p less than 0.01). Using multivariable proportional hazards analysis, uncorrected coronary artery disease was associated with a nearly twofold increased risk of death (hazard ratio 1.79, 95% confidence interval 1.06 to 3.00) and a fourfold increased risk of cardiac events (hazard ratio 3.71, 95% confidence interval 1.79 to 7.69). These population-based data support an aggressive life-long approach to the management of coronary artery disease in patients undergoing abdominal aortic aneurysmectomy.

Influence of coronary heart disease on morbidity and mortality after carotid endarterectomy: a population-based study in Olmsted County, Minnesota (1970-1988)

To evaluate the prognostic importance of coronary artery disease among patients undergoing carotid endarterectomy, 177 residents of Olmsted County, Minnesota who underwent carotid endarterectomy during the period 1970 through 1988 were followed up to July 1, 1989. Patients were stratified as to the presence (n = 64) or absence (n = 93) of overt coronary artery disease or prior myocardial revascularization (n = 20) at the time of endarterectomy. At 30 days after carotid endarterectomy, there were no significant differences between patients with or without coronary artery disease in the occurrence of death, myocardial infarction or stroke. Kaplan-Meier estimate of 8-year relative survival after carotid endarterectomy (assessed as a percent of survival in age- carotid endarterectomy (assessed as a percent of survival in age- and gender-matched control subjects) was 89% in those without and 75% in those with overt coronary artery disease. Of the 59 total deaths, 29 (49%) had a cardiac cause and 4 (7%) were due to stroke (p less than 0.0001). The cumulative incidence of a cardiac event at 8 years after carotid endarterectomy was greater in those with than in those without overt coronary artery disease (61% vs. 25%, p less than 0.0001). In multivariable analysis, uncorrected coronary artery disease and diabetes were the only independent predictors of subsequent cardiac events, whereas age was the only independent predictor of death. These population-based data suggest that carotid endarterectomy can be safely undertaken in patients with stable coronary artery disease. In long-term follow-up of these patients, coronary rather than cerebral vascular disease is the most frequent cause of morbidity and mortality. Thus, these data lend strong support to the concept of early identification and management of coronary artery disease in patients undergoing carotid endarterectomy.

Influence of coronary heart disease on morbidity and mortality after lower extremity revascularization surgery: a population-based study in Olmsted County, Minnesota (1970-1987).

OBJECTIVES: The aim of this study was to evaluate the short- and long-term postoperative cardiac outcome of patients undergoing lower extremity revascularization surgery in a geographically defined patient group. BACKGROUND: Among patients with peripheral vascular disease, cardiac events have an important effect on long-term outcome after peripheral vascular surgery. However, long-term outcome is poorly documented. METHODS: We examined the entire community medical records of 173 residents of Olmsted County, Minnesota, who underwent peripheral artery bypass surgery between 1970 and 1987 and were followed up to January 1, 1991. Patients were allocated to subgroups of 60 patients with and 106 patients without overt coronary artery disease. RESULTS: There were no significant differences in perioperative death, myocardial infarction or stroke between subgroups at 30 days after operation. The 5- and 10-year Kaplan-Meier survival rate after operation was 77% and 51% in those without and 54% and 24% in those with overt coronary artery disease (p < 0.001), respectively. For both groups, survival was significantly poorer than that expected for an age- and gender-matched group. Patients undergoing aortoiliac surgery were more likely to be alive at 10 years than those undergoing femoropopliteal surgery (47% vs. 28%, p = 0.001). The 5-year cumulative incidence of cardiac events was greater in those with overt coronary artery disease (50% vs. 28%, p = 0.003). In multivariable analysis, age, coronary artery disease and diabetes were independent predictors of death. CONCLUSIONS: Coronary events are the most important cause of long-term morbidity and mortality after peripheral vascular surgery. Patients without overt coronary artery disease are at significant risk for long-term cardiac events.

Relation between mode of pacing and long-term survival in the very elderly.

OBJECTIVES: This study analyzes the relationship between pacing mode and long-term survival in a large group of very elderly patients (> or = 80 years old). BACKGROUND: The relationship between pacing mode and long-term survival is not clear. Because the number of very elderly who are candidates for pacing is increasing, issues related to pacemaker (PM) use in the elderly have important clinical and economic implications. METHODS: We retrospectively reviewed 432 patients (mean age, 84.5+/-3.9 years) who received their initial PM (ventricular in 310 and dual chamber in 122) between 1980 and 1992. Follow-up was complete (3.5+/-2.6 years). Observed survival was estimated by the Kaplan-Meier method. Age- and gender-matched cohorts from the Minnesota population were used for expected survival. Log-rank test and Cox regression hazard model were used for univariate and multivariate analyses. RESULTS: Patients with ventricular PMs appeared to have poor overall survival compared with those with dual-chamber PMs. Observed survival after PM implantation in high grade atrioventricular block (AVB) patients was significantly worse than expected survival of the age- and gender-matched population (p < 0.0001), whereas observed survival of patients with sinus node dysfunction was not significantly different from expected survival of the matched population (p = 0.413). By univariate analysis, ventricular pacing in patients with AVB appeared to be associated with poor survival compared with dual-chamber pacing (hazard ratio [HR] 2.08; 95% confidence interval [CI] 1.33 to 3.33). After multivariate analysis, this difference was no longer significant (HR 1.41; 95% CI 0.88 to 2.27). Independent predictors of all-cause mortality were number of comorbid illnesses, New York Heart Association functional class, left ventricular depression and older age at implant. Pacing mode was not an independent predictor of overall survival. Older age at implantation, diabetes mellitus, dementia, history of paroxysmal atrial fibrillation and earlier year of implantation were independent predictors of ventricular pacemaker selection. CONCLUSIONS: After PM implantation, long-term survival among very elderly patients was not affected by pacing mode after correction of baseline differences. Selection bias was present in pacing mode in the very elderly, with ventricular pacing selected for sicker and older patients, perhaps partly explaining the apparent "beneficial impact on survival" observed with dual-chamber pacing.

Y chromosome STR haplotypes in three UK populations.

Eleven Y chromosome short tandem repeat markers: DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438 and DYS439, have been typed in the three main UK population groups: Caucasians, Afro-Caribbeans and South Asians. Existing PCR reactions were adapted to incorporate DYS437, DYS438 and DYS439. The observed 11 loci haplotypes and the individual allele frequencies for each locus are presented. Distinct differences for most markers were observed between the population groups studied.

A study of mutation rates and the characterisation of intermediate, null and duplicated alleles for 13 Y chromosome STRs.

Previously reported Y chromosome STR haplotype databases for three UK population groups, plus additionally analysed samples, have been scrutinised for the presence of non-standard (intermediate, null and duplicated) alleles. These alleles have been characterised by sequencing, some showing changes in the repeat structure, and the frequencies reported. Mutation rates for each of the 13 STRs have been calculated when analysis of father-son pairs has been possible. An example illustrating the use of non-standard alleles in a large family tree is outlined.

Positive predictive value of clinical suspicion of abdominal aortic aneurysm. Implications for efficient use of abdominal ultrasonography.

Although selective screening for an abdominal aortic aneurysm (AAA) by abdominal palpation aimed at detecting AAAs has engendered considerable support, no population-based data pertaining to the positive predictive value (PPV) of the clinical assessment of AAAs in routine clinical practice are available. Therefore, we used the unique resources of the Rochester (Minn) Epidemiology Project and the Mayo Clinic computerized abdominal ultrasonography database to identify all residents of Olmsted County, Minnesota,who underwent ultrasound examination for a clinically suspected AAA between November 1, 1985, and October 31, 1987. Of 116 residents who were suspected of having an AAA on abdominal palpation and were referred for an ultrasound examination for confirmation, 17 patients had a 3.5-cm or greater AAA by ultrasound examination (PPV = 14.7%). The probability of AAA by ultrasound examination (PPV = 14.7%). The probability of AAA documentation by ultrasound examination given clinical suspicion of an AAA was associated with higher body mass index, older age,and presence of other macrovascular disease. In 17 patients aged 70 years or younger, without other macrovascular disease and with body mass index of 24 or less, only 1 had an AAA of 3.5 cm or greater (PPV = 6%), while 10 of 20 patients aged 70 years or older, with macrovascular disease,and with body mass index greater than 24 had an AAA of 3.5 cm or greater (PPV = 50%). These population-based data that highlight the poor PPV of the clinical assessment for AAAs indicate that abdominal palpation aimed at detecting AAAs as part of a periodic health examination may lead to a much higher rate of false-positive results than indicated by previous referral-based data. Further research is needed to identify patient subgroups in whom abdominal palpation for detection of AAAs will be cost-effective with respect to reduction in AAA mortality.

Learning from the last ultrasound. A population-based study of patients with abdominal aortic aneurysm.

BACKGROUND: Patients with abdominal aortic aneurysm often are followed up with serial ultrasound examinations, but published studies usually describe rupture risk according to the diameter of the abdominal aortic aneurysm at diagnosis rather than by most recent ultrasound. Information in this form is misleading when used to predict prognosis. METHODS: We used data from the population-based cohort of residents of Rochester, Minn, diagnosed as having abdominal aortic aneurysm who have had at least 1 ultrasound measurement. Of the 181 patients who were enrolled in this cohort between January 1, 1974, and December 31, 1988, 5 had clinical evidence of rupture at entry. Analysis of a cohort defined by size category at "last ultrasound" was undertaken to assess rupture risk and growth rate. RESULTS: Median overall aneurysmal growth rate was 0.21 cm/y. Initial growth rate did not correlate with subsequent growth rate (r = 0.18; P = .14) or with initial size (r = -0.12; P = .22). Only 1 aneurysm ruptured when last ultrasound was less than 5 cm, and this occurred 3 1/2 years after this ultrasound. Estimated rupture risk by last ultrasound was 0% per year (95% confidence interval [CI], 0%-5%) when less than 4.00 cm, 1.0% per year (95% CI, 0%-5%) when 4.00 to 4.99 cm, and 11% per year (95% CI, 1%-21%) when 5.00 to 5.99 cm. CONCLUSIONS: The most clinically useful approach to estimating the risk of abdominal aortic aneurysm rupture is according to size at last ultrasound. Aneurysm growth rate is predicted neither by size nor by initial growth rate.

The contribution of non-insulin-dependent diabetes to lower-extremity amputation in the community.

BACKGROUND: Despite the significant public health burden of lower-extremity amputations in diabetes mellitus, few data are available on the epidemiology of lower-extremity amputations in diabetes mellitus in the community setting. METHODS: A retrospective incidence cohort study based in Rochester, Minn, was conducted. RESULTS: Among the 2015 diabetic individuals free of lower-extremity amputation at the diagnosis of diabetes mellitus, 57 individuals underwent 79 lower-extremity amputations (incidence, 375 per 100,000 person-years; 95% confidence interval, 297 to 467). Among the 1826 patients with non-insulin-dependent diabetes mellitus, 52 underwent 73 lower-extremity amputations, and the subsequent incidence of lower-extremity amputation among these residents was 388 per 100,000 person-years (95% confidence interval, 304 to 487). Of the 137 insulin-dependent diabetic patients, four subsequently underwent five lower-extremity amputations (incidence, 283 per 100,000 person-years; 95% confidence interval, 92 to 659). Twenty-five years after the diagnosis of diabetes mellitus, the cumulative risk of one lower-extremity amputation was 11.2% in insulin-dependent diabetes mellitus and 11.0% in non-insulin-dependent diabetes mellitus. When compared with lower-extremity amputation rates for Rochester residents without diabetes, patients with non-insulin-dependent diabetes mellitus were nearly 400 times more likely to undergo an initial transphalangeal amputation (rate ratio, 378.8) and had almost a 12-fold increased risk of a below-knee amputation (rate ratio, 11.8). In this community, more than 60% of lower-extremity amputations were attributable to non-insulin-dependent diabetes mellitus. CONCLUSIONS: These population-based data document the magnitude of the elevated risk of lower-extremity amputation among diabetic individuals. Efforts should be made to identify more precisely risk factors for amputation in diabetes and to intervene in the processes leading to amputation.

Incidence of diabetic retinopathy and blindness: a population-based study in Rochester, Minnesota.

Among the 1135 Rochester residents discovered to have diabetes in the period 1945-69, the prevalence of retinopathy was 2.6% at the time of initial diagnosis. Among those free of retinopathy at diagnosis of diabetes, the subsequent incidence of any retinopathy was 17.4 per 1000 person-years and for proliferative retinopathy alone was 1.6 per 1000 person-years, based on 12,000 person-years of follow-up. The incidence rate of retinopathy was almost three times greater among residents with insulin-dependent (IDDM) than with non-insulin-dependent diabetes (NIDDM); however, the actual number of retinopathy cases was over four times greater among the more numerous residents with NIDDM. By 20 yr after diagnosis of diabetes, the cumulative incidence of retinopathy approached 70% among IDDM subjects and was 30% and 36%, respectively, among the obese and nonobese NIDDM residents. The epidemiologic patterns for proliferative retinopathy were qualitatively similar to those for nonproliferative retinopathy. The risk of blindness was greater among those with proliferative than with nonproliferative retinopathy but was substantial even for those without retinopathy. Most blindness was caused by factors other than isolated diabetic retinopathy.

Risk factors for diabetic retinopathy: a population-based study in Rochester, Minnesota.

Retinopathy is an important sequela of diabetes mellitus, but clinical risk factors for this condition have rarely been assessed in a geographically defined population. In this population-based study, the 1135 Rochester, Minnesota, residents with diabetes mellitus initially diagnosed between 1945 and 1969 (incidence cohort) were followed through their complete medical records in the community to January 1, 1982. Because most of the cases of diabetic retinopathy in Rochester residents developed in patients with non-insulin-dependent diabetes mellitus (NIDDM), risk factors for diabetic retinopathy were examined in this group (N = 1031). A proportional hazards model identified the following risk factors for diabetic retinopathy in NIDDM: elevated initial fasting blood glucose level, marked obesity, and earlier age at onset of diabetes. Stratified analyses indicated that duration of diabetes was also significantly associated with an increased risk of retinopathy. Two secular trends, increasing detection of "mild" NIDDM and decreasing risk of diabetic retinopathy, had a major effect on retinopathy risk assessment. These data also suggest that insulin therapy is not an independent risk factor for diabetic retinopathy.

Rheumatoid pericarditis: clinical features and survival.

We describe the clinical characteristics and actuarial survival of a consecutive cohort of 41 patients with rheumatoid arthritis and clinical pericarditis who were seen at the Mayo Clinic between 1970 and 1987 and followed up until death or through 1987. The survivors were followed up for a median of 5.1 years. Approximately three-fourths of our patients had acute pericarditis, the remainder having recurrent acute pericarditis, chronic pericarditis with effusion, or chronic constrictive pericarditis. Most patients had symmetrical joint swelling, morning stiffness, subcutaneous nodules, rheumatoid factor, and classic radiographic changes of rheumatoid arthritis. Common extra-articular features included fatigue, loss of weight, and fever. Dyspnea or orthopnea, typical pericardial pain, peripheral edema, tachycardia, tachypnea, a diminished mean blood pressure, a pericardial friction rub, jugular venous distension, rales, radiographic evidence of cardiomegaly and pleural effusions, and abnormal echocardiograms were the most common cardiac manifestations. An elevated erythrocyte sedimentation rate and anemia were other common laboratory findings. Our cohort demonstrated decreased survival in comparison with an age- and sex-matched North Central white population (from the upper midwestern United States), especially during the first year after diagnosis. Increasing age, the presence of other heart disease, an increasing total number of other extra-articular manifestations of rheumatoid arthritis, jugular venous distention, and a lower mean blood pressure were associated with decreased survival.

Rheumatoid vasculitis: survival and associated risk factors.

We describe the clinical and laboratory characteristics of 52 patients with rheumatoid vasculitis whose condition was diagnosed at a tertiary care center between 1974 and 1981, and we report their survival and the factors that were associated with decreased survival. The patients with rheumatoid vasculitis had decreased survival in comparison with an age-, sex-, and region-matched general population. Their survival was also decreased in comparison to that of an incidence cohort of community patients with rheumatoid arthritis. In the latter cohort, decreased survival was confined to those patients with classic but not definite rheumatoid arthritis. After partial correction for referral bias, we found no difference in survival between the cohort with rheumatoid vasculitis and the cohort with classic rheumatoid arthritis. We found that the age at diagnosis of rheumatoid vasculitis, the therapeutic decisions before and at diagnosis, and the referral distance were the best predictors of survival. Abnormal urinary sediment and hypergammaglobulinemia also predicted poor survival, but because of a lack of specificity in a small number of clinically abnormal values, we urge a cautious interpretation of their importance.

Clinical risk factors for Alzheimer's disease: a population-based case-control study.

Using information on clinical risk factors provided through the medical record linkage system of the Rochester Epidemiology Project, we conducted a population-based case-control study of Alzheimer's disease (AD). During the period 1960 to 1974, we identified 415 newly diagnosed cases of AD among residents of Rochester, Minnesota, and matched one community control to each case based on age, sex, and duration of community medical record. We estimated odds ratios using conditional logistic regression for several potential clinical risk factors of AD. Among more than 20 clinical risk factors that were evaluated, the only statistically significant findings were for episodic depression, personality disorder, and hypertension.

Prognostic value of exercise radionuclide angiography in a population-based cohort of patients with known or suspected coronary artery disease.

Five hundred thirty-six residents of Olmsted County, Minnesota, who underwent supine rest and exercise radionuclide angiography because of known or suspected coronary artery disease, were followed for a median of 46 months to determine the prognostic value of exercise radionuclide angiography in a community population who generally did not undergo coronary angiography. There were 71 persons who experienced a new cardiac event (the initial events were cardiac death and nonfatal myocardial infarction in 26 and 45 persons, respectively). A proportional-hazards model identified 4 independent predictors of cardiac events: exercise ejection fraction (p < 0.001), exercise heart rate (p < 0.001), and age (p = 0.04). Four-year infarct-free survival was 98% for the 152 patients with a peak exercise heart rate at or above the median (122 beats/min) and an exercise ejection fraction at or above the median (0.58). In the 150 patients with a peak exercise heart rate < 122 beats/min and an exercise ejection fraction < 0.58, 4-year infarct-free survival was 68%. When this population-based cohort was compared with a referral case series previously reported from our institution, these population-based patients were significantly more likely to be men, to have typical angina, to have higher exercise heart rates and exercise ejection fractions, and were less likely to be receiving beta-receptor antagonist therapy. At each level of exercise ejection fraction, the population-based patients had a slightly but insignificantly greater risk than referral patients for subsequent cardiac events. These population-based data provide strong evidence of the prognostic value of exercise radionuclide angiography in community practice.