Biomedical subjects

Sara Partington

Publications and source records attributed to Sara Partington.

4 recordsLinked to original sources

PubMed2003

The effect of ethnicity on survival in male veterans referred for electrocardiography and treadmill testing.

BACKGROUND: Ethnic differences in the relationship between access to health care and survival are difficult to define because of many confounding factors, such as socioeconomic status and baseline differences in health. Because the Veterans Affairs health care system offers health care largely without financial considerations, it provides an ideal setting in which to identify and understand ethnic differences in health outcomes. Previous studies in this area have lacked clinical and cardiovascular data with which to adjust for baseline differences in patients' health. METHODS: Data were collected from consecutive men referred for resting electrocardiography (ECG) (n = 41 087) or exercise testing (n = 6213) during 12 years. We compared ethnic differences in survival between whites, blacks, and Hispanics after considering baseline differences in age and hospitalization status. We also adjusted for electrocardiogram abnormalities and cardiac risk factors, exercise test results, and cardiovascular comorbidities. RESULTS: White patients tended to be older and had more baseline comorbidities and cardiovascular interventions when they presented for testing. White patients had increased mortality rates compared with blacks and Hispanics. In the ECG population, after adjusting for demographics and baseline electrocardiogram abnormalities, Hispanics had improved survival compared with whites and blacks. In the exercise test population, after adjusting for the same factors, as well as adjusting for the presence of cardiovascular comorbidities, cardiac risk factors, and exercise test findings, Hispanics also exhibited improved survival compared with the other 2 ethnicities. There were no differences in mortality rates between whites and blacks. CONCLUSION: Our findings demonstrate that the health care provided to veterans referred for routine ECG or exercise testing is not associated with poorer survival in ethnic minorities.

Aged↗

PubMed2003

Prevalence and prognostic value of exercise-induced ventricular arrhythmias.

OBJECTIVE: The purpose of this study was to determine the prevalence and prognostic significance of exercise-induced ventricular arrhythmias (EIVAs) in patients referred for exercise testing, considering the arrhythmic substrate and exercise-induced ischemia. BACKGROUND: EIVAs are frequently observed during exercise testing, but their prognostic significance is uncertain. The design of this study was a retrospective analysis of prospectively collected data, and it took place in 2 university-affiliated Veterans Affairs Medical Centers. Patients comprised 6213 consecutive males referred for exercise tests. We measured clinical exercise test responses and all-cause mortality after a mean follow-up of 6 +/- 4 years. EIVAs were defined as frequent premature ventricular contractions (PVCs) constituting >10% of all ventricular depolarizations during any 30 second electrocardiogram recording, or a run of > or =3 consecutive PVCs during exercise or recovery. RESULTS: A total of 1256 patients (20%) died during follow-up. EIVAs occurred in 503 patients (8%); the prevalence of EIVAs increased in older patients and in those with cardiopulmonary disease, resting PVCs, and ischemia during exercise. EIVAs were associated with mortality irrespective of the presence of cardiopulmonary disease or exercise-induced ischemia. In those without cardiopulmonary disease, mortality differed more so later in follow up than earlier. In those without resting PVCs, EIVAs were also predictive of mortality, but in those with resting PVCs, poorer prognosis was not worsened by the presence of EIVAs. CONCLUSIONS: Exercise induced ischemia does not affect the prognostic value of EIVAs, whereas the arrhythmic substrate does. EIVAs and resting PVCs are both independent predictors of mortality after consideration of other clinical and exercise-test variables. These findings are of limited clinical significance because of the modest change in risk and the lack of any established intervention. However, they explain some of the previous controversy and highlight the need to consider resting PVCs and follow-up duration in assessing the clinical implications of EIVAs.

Electrocardiography↗

PubMed2002

The prognostic value of exercise testing in elderly men.

PURPOSE: Our purposes were to compare the responses to exercise testing in elderly (> or =65 years of age) and younger men, and to investigate whether exercise testing has similar prognostic value in the two age groups. METHODS: We included all elderly (n = 1185) and younger (n = 2789) male veterans without established coronary heart disease who underwent routine clinical exercise testing between 1987 and 2000 at two academically affiliated Veteran's Affairs medical center laboratories. Measurements included a standardized medical history, exercise testing, and all-cause mortality. RESULTS: Compared with younger patients, elderly patients achieved a lower workload (a mean [+/- SD] of 7 +/- 3 vs. 10 +/- 4 metabolic equivalents [METs], P <0.001) and were more likely to have abnormal ST depression (27% [n = 324] vs. 16% [n = 436], P <0.001). During the mean follow-up of 6 years, annual mortality was twice as high among elderly patients as among younger patients (4% vs. 2%, P <0.001). The only exercise test variable that was associated significantly with time to death in both age groups was maximal METs achieved: each 1 MET increase in exercise capacity was associated with an 11% reduction in annual mortality. Exercise-induced ST depression was more common in those who subsequently died, but was not an independent predictor of mortality. CONCLUSION: In elderly men, exercise testing provided prognostic information incremental to clinical data. Achieved workload (in METs) was the major exercise testing variable associated with all-cause mortality. Its prognostic importance was the same in elderly as in younger men.

Age Factors↗

PubMed2002

Exercise capacity and mortality among men referred for exercise testing.

BACKGROUND: Exercise capacity is known to be an important prognostic factor in patients with cardiovascular disease, but it is uncertain whether it predicts mortality equally well among healthy persons. There is also uncertainty regarding the predictive power of exercise capacity relative to other clinical and exercise-test variables. METHODS: We studied a total of 6213 consecutive men referred for treadmill exercise testing for clinical reasons during a mean (+/-SD) of 6.2+/-3.7 years of follow-up. Subjects were classified into two groups: 3679 had an abnormal exercise-test result or a history of cardiovascular disease, or both, and 2534 had a normal exercise-test result and no history of cardiovascular disease. Overall mortality was the end point. RESULTS: There were a total of 1256 deaths during the follow-up period, resulting in an average annual mortality of 2.6 percent. Men who died were older than those who survived and had a lower maximal heart rate, lower maximal systolic and diastolic blood pressure, and lower exercise capacity. After adjustment for age, the peak exercise capacity measured in metabolic equivalents (MET) was the strongest predictor of the risk of death among both normal subjects and those with cardiovascular disease. Absolute peak exercise capacity was a stronger predictor of the risk of death than the percentage of the age-predicted value achieved, and there was no interaction between the use or nonuse of beta-blockade and the predictive power of exercise capacity. Each 1-MET increase in exercise capacity conferred a 12 percent improvement in survival. CONCLUSIONS: Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.

Adrenergic beta-Antagonists↗