PubMed Health⌕ Search

Biomedical subjects

Dean E Smith

Publications and source records attributed to Dean E Smith.

28 records · Page 2Linked to original sources
PubMed2003

Comparison of patients with acute coronary syndrome with and without systemic hypertension.

The role of systemic hypertension in acute coronary syndrome (ACS) has not been well studied. We studied consecutive subjects admitted to the University of Michigan Health System (Ann Arbor, Michigan) with symptoms of ACS. Data were collected using a standardized form. This observational study is currently ongoing; we collected data from May 1999 to December 2000 for 979 subjects, 890 of whom also had 6-month follow-up data. Hypertensives represented 64.4% (n = 630) of the total population. In general, hypertensive patients were older than normotensives (66.3 vs 59.9 years, p <0.0001), more often women (38.7% vs 26.9%, p = 0.0002), and had more comorbidities, such as previous myocardial infarction (47.9% vs 33.8%, p <0.0001), congestive heart failure (25.7% vs 12.0%, p <0.0001), and diabetes (36.9% vs 17.8%, p <0.0001). At admission, hypertensives had higher systolic blood pressure. Hypertensives had fewer electrocardiographic abnormalities indicating ischemic changes (67.9% vs 76.3%, p = 0.01) and had fewer incident of acute myocardial infarction (AMI) (70.7% vs 76.1%, p = 0.07) than normotensives. There was consistency over different levels of admission systolic blood pressure. Hypertensives received more oral cardiovascular drugs, and had undergone more invasive procedures. The lower rate of AMI in hypertensives seemed to be related to the higher frequency of a history of percutaneous coronary intervention and coronary artery bypass grafting. However, at 6-month follow-up, age- and gender-adjusted odds ratios for adverse events were equivalent in hypertensives and normotensives, suggesting no continuing differential treatment benefit for hypertensives in the months after the initial ACS episode.

Acute Disease↗
PubMed2002

Chronobiological patterns of acute aortic dissection.

BACKGROUND: Chronobiological rhythms have been shown to influence the occurrence of a variety of cardiovascular disorders. However, the effects of the time of the day, the day of the week, or monthly/seasonal changes on acute aortic dissection (AAD) have not been well studied. METHODS AND RESULTS: Accordingly, we evaluated 957 patients enrolled in the International Registry of Acute Aortic Dissection (IRAD) between 1996 and 2000 (mean age 62+/-14 years, type A 61%). A chi2 test for goodness of fit and partial Fourier analysis were used to evaluate nonuniformity and rhythmicity of AAD during circadian, weekly, and monthly periods. A significantly higher frequency of AAD occurred from 6:00 AM to 12:00 noon compared with other time periods (12:00 noon to 6:00 PM, 6:00 PM to 12:00 midnight, and 12:00 midnight to 6:00 AM; P<0.001 by chi2 test). Fourier analysis showed a highly significant circadian variation (P<0.001) with a peak between 8:00 AM and 9:00 AM. Although no significant variation was found for the day of the week, the frequency of AAD was significantly higher during winter (P=0.008 versus other seasons by chi2 test). Fourier analysis confirmed this monthly variation with a peak in January (P<0.001). Subgroup analysis identified a significant association for all subgroups with circadian rhythmicity. However, seasonal/monthly variations were observed only among patients aged <70 years, those with type B AAD, and those without hypertension or diabetes. CONCLUSIONS: Similar to other cardiovascular conditions, AAD exhibits significant circadian and seasonal/monthly variations. Our findings may have important implications for the prevention of AAD by tailoring treatment strategies to ensure maximal benefits during the vulnerable periods.

Aged↗
PubMed2002

Acute type A aortic dissection in the elderly: clinical characteristics, management, and outcomes in the current era.

OBJECTIVES: We sought to evaluate the clinical characteristics, management, and outcomes of elderly patients with acute type A aortic dissection. BACKGROUND: Few data exist on the clinical manifestations and outcomes of acute type A aortic dissection in an elderly patient cohort. METHODS: We categorized 550 patients with type A aortic dissection enrolled in the International Registry of Acute Aortic Dissection into two age strata (<70 and >or=70 years) and compared their clinical features, management, and in-hospital events. RESULTS: Thirty-two percent of patients with type A dissection were aged >or=70 years. Marfan syndrome was exclusively associated with dissection in the young, whereas hypertension, atherosclerosis and iatrogenic dissection predominated in older patients. Typical symptoms (abrupt onset of chest or back pain) and signs (aortic regurgitation murmur or pulse deficits) of dissection were less common among the elderly. Fewer elderly patients were managed surgically than younger patients (64% vs. 86%, p < 0.0001). Hypotension occurred more frequently (46% vs. 32%, p = 0.002) and focal neurologic deficits less frequently (18% vs. 26%, p = 0.04) among the elderly. In-hospital mortality was higher among older patients (43% vs. 28%, p = 0.0006). Logistic regression analysis identified age >or=70 years as an independent predictor of hospital death for acute type A aortic dissection (odds ratio 1.7, 95% confidence interval 1.1-2.8; p = 0.03). CONCLUSIONS: Our study shows significant differences between older (age >or=70 years) and younger (age <70 years) patients with acute type A aortic dissection in their clinical characteristics, management, and hospital outcomes. Future research should evaluate strategies to improve outcomes in this high-risk elderly cohort.

Acute Disease↗
PubMed2002

The new definition of myocardial infarction: diagnostic and prognostic implications in patients with acute coronary syndromes.

BACKGROUND: The clinical implications of the recently revised criteria for diagnosis of acute myocardial infarction (AMI) in patients with suspected acute coronary syndromes are unknown. METHODS: To evaluate the prognostic implications of the new diagnostic criteria for AMI, we studied 493 consecutive patients with suspected acute coronary syndromes admitted to University of Michigan, Ann Arbor, between May 1, 1999, and January 1, 2000. Patients with positive cardiac enzymes and symptoms suggestive of coronary ischemia (n = 275) were divided into 2 groups: group A, with elevated peak creatine kinase-MB fraction and/or new electrocardiographic changes suggestive of AMI regardless of troponin status (diagnosed as AMI by old criteria), and group B, with normal peak creatine kinase-MB fraction but elevated troponin I level (additional patients diagnosed as having AMI by new criteria). RESULTS: As compared with group A (n = 224), patients in group B (n = 51) were older women, with increased comorbidities such as previous stroke or aortic stenosis, and had fewer in-hospital procedures. In-hospital adverse events (reinfarction, heart failure, shock, and mortality) were similar between the groups, whereas 6-month mortality was higher among group B patients (16.3% vs 5.8%; P =.03). This difference was not statistically significant after adjustment for differences in baseline characteristics between the groups (odds ratio, 1.6; 95% confidence interval, 0.5-5.9). CONCLUSIONS: The new criteria result in a substantial increase in the diagnosis of AMI. Furthermore, they help to identify patients with acute coronary syndromes who have greater comorbidities and worse 6-month outcomes who are otherwise missed by the old criteria. Additional studies are needed to confirm these preliminary findings and to determine the financial implications of the new criteria.

Acute Disease↗
PubMed2002

Usefulness of pulse deficit to predict in-hospital complications and mortality in patients with acute type A aortic dissection.

Vascular compromise seen with pulse deficits is common in patients with type A dissection. However, patient characteristics and in-hospital outcomes associated with pulse deficits have not been evaluated. Accordingly, we studied 513 patients (mean age 62 +/- 14 years, 65% men) with acute type A aortic dissection enrolled in the International Registry of Acute Aortic Dissection. Pulse deficits, defined as decreased or absent carotid or peripheral pulses as noted by clinicians and later confirmed by diagnostic imaging, at surgery or at autopsy were noted in 154 patients (30%). Age <70 years, male gender, neurologic deficit(s), altered mental status, and hypotension, shock, or tamponade on admission were all significantly higher in patients with than without pulse deficits. The etiology of aortic dissection, clinical symptoms, and imaging findings were similar in the 2 groups. In-hospital complications (hypotension, coma, renal failure, and limb ischemia) and mortality (41% vs 25%, p = 0.0002) were significantly higher in patients with pulse deficit. Cox proportional-hazards regression analysis identified pulse deficit as an independent predictor of 5-day in-hospital mortality (risk ratio 2.73, 95% confidence interval 1.7 to 4.4; p <0.0001). Further, overall mortality rates increased with an increasing number of pulse deficits (p for trend <0.0001). Pulse deficits are common findings in patients with type A aortic dissection and identify those at high risk of in-hospital adverse events. This simple clinical sign should direct physicians to consider a diagnosis of aortic dissection in patients with acute chest pain, and should help identify a subgroup of patients who would benefit from more aggressive strategies.

Aged↗
PubMed2002

Predicting death in patients with acute type a aortic dissection.

BACKGROUND: Given the high mortality rates in patients with type A aortic dissection, predictive tools to identify patients at increased risk of death are needed to assist clinicians for optimal treatment. METHODS AND RESULTS: Accordingly, we evaluated 547 patients with this diagnosis enrolled in the International Registry of Acute Aortic Dissection (IRAD) between January 1996 and December 1999. Univariate testing followed by multivariate logistic regression analysis was performed to identify independent predictors of death. In-hospital mortality rate was 32.5% in type A dissection patients. In-hospital complications (neurological deficits, altered mental status, myocardial or mesenteric ischemia, kidney failure, hypotension, cardiac tamponade, and limb ischemia) were increased in patients who died compared with survivors (P<0.05 for all). Logistic regression identified the following presenting variables as predictors of death: age > or =70 years (OR, 1.70; 95% CI, 1.05 to 2.77; P=0.03), abrupt onset of chest pain (OR 2.60; 95% CI, 1.22 to 5.54; P=0.01), hypotension/shock/tamponade (OR, 2.97; 95% CI, 1.83 to 4.81; P<0.0001), kidney failure (OR, 4.77; 95% CI, 1.80 to 12.6; P=0.002), pulse deficit (OR, 2.03; 95% CI, 1.25 to 3.29, P=0.004), and abnormal ECG (OR, 1.77; 95% CI, 1.06 to 2.95; P=0.03) (area under receiver operating curve, 0.74; Hosmer-Lemeshow statistic, P=0.75). CONCLUSIONS: The in-hospital mortality rate in acute type A aortic dissection is high and can be predicted with the use of a clinical model incorporated in a simple risk prediction tool. This tool can be used to educate patients with dissection about their predicted risk and in clinical research for risk adjustment while comparing outcomes of different therapies.

Aged↗
PubMed2002

Carotid artery reactivity to isometric hand grip exercise identifies persons at risk and with coronary disease.

BACKGROUND: The change in brachial artery diameter (DBA(d)) following release of an occluding cuff (BAO(cclR)) has been used to characterize local endothelial function and coronary risk. We designed a study to determine the CA diameter (CA(d)) response to exercise (IHG), whether the response is influenced by coronary risk, and compare it with the BAO(cclR) method. METHOD AND RESULTS: High resolution ultrasound was used to detect the DCA(d) in response to120 s of 33% of maximum and DBA(d) was measured 60 s following release of an occluding cuff. There was no change in CA(d) during IHG. At 90 s following release, CA(d) dilated >0.1 mm in 95% of volunteers with average risk (mean 0.42+/-0.25 mm or 5.97+/-3.5%). There was no change or constriction in 62% of high risk (0.01+/-0.28 mm, 0.0+/-3.6%), and predominantly constriction in CAD subjects (-0.22+/-0.23 mm, -0.01+/-3.2%), P=0.0001 for trend and 0.01 between groups. The %DCA(d) following IHG and %DBA(d) following OcclR were highly correlated, r=0.66, P=0.0001. The major determinant of response to each stressor was group (%DBA(d) R(2)=0.55 and %DCA(d) R(2)=0.52). CONCLUSIONS: The reactivity of the carotid artery to IHG is highly influenced by coronary risk, and may be an additional modality to characterize pre-clinical CAD and assess treatment strategies.

Adult↗
PubMed2002

Cholesterol predicts stroke mortality in the Women's Pooling Project.

BACKGROUND AND PURPOSE: Cholesterol is emerging as a risk factor for stroke; however, few data are available regarding the relation of cholesterol and stroke mortality in women and ethnic minorities. METHODS: We evaluated the risk of death caused by total stroke, nonhemorrhagic stroke, and hemorrhagic stroke by race, age, and cholesterol quintile in 24 343 women with no previous cardiovascular disease who were participating in 8 US longitudinal, prospective, cohort studies included in the Women's Pooling Project. RESULTS: We observed 568 stroke deaths (461 nonhemorrhagic, 83 hemorrhagic) for women > or =30 years of age without previous cardiovascular disease during 339 215 person-years of follow-up. In multivariate models, black women <55 years of age had a 76% increased risk of death caused by stroke compared with white women [relative risk (RR), 1.76; 95% confidence interval (CI), 1.10 to 2.81]. For black women <55 years of age, the top compared with the lowest cholesterol quintile (Q5 versus Q1) remained an independent predictor of stroke mortality (RR, 2.58; 95% CI, 1.05 to 6.32) in multivariate models. For white women <55 years of age, Q5 versus Q1 cholesterol did not predict stroke mortality with significance (RR, 1.47; 95% CI, 0.57 to 3.76). In analogous multivariate models, we found a positive relation between continuous cholesterol and nonhemorrhagic stroke death in women <55 years of age (RR, 1.23; 95% CI, 1.02 to 1.49). CONCLUSIONS: Our results show that cholesterol is a risk factor for nonhemorrhagic stroke death in women <55 years of age and is more strongly associated with mortality in black women <55 years of age than in white women. These data document the importance of cholesterol in addition to established risk factors for predicting stroke mortality in young women and may guide prevention strategies.

Adult↗
PubMed2002

Health-related quality of life in patients 7 months after a myocardial infarction: factors affecting the Short Form-12.

We assessed patients' health-related quality of life after myocardial infarction and identified related variables. Clinical data were obtained retrospectively from medical records of consecutive patients admitted to a Midwestern university-affiliated medical center with diagnosis of myocardial infarction from July 1999-July 2000. Telephone interviews 7 months after discharge were made to administer the Short Form-12 (SF-12) and obtain patient, disease, drug, and intervention data. Complete information was obtained from 200 patients (mean age 63.4 +/- 13.1 yrs, 68% men). The mean Physical Component Summary (PCS)-12 score was 40.6 +/- 12.0, and the mean Mental Component Summary (MCS)-12 score was 52.1 +/- 10.0. Based on univariate analyses, low PCS-12 scores were associated with women; non-Q-wave infarctions; greater number of illnesses; history of myocardial infarction, chronic heart failure (CHF), transient ischemic attack (TIA), renal disease, peripheral vascular disease, or percutaneous coronary intervention (PCI); rehospitalization during the interim period; and unscheduled PCI since index myocardial infarction. Low MCS-12 scores were associated with age below 65 years, low overall self-reported drug therapy compliance, low self-reported compliance with angiotensin-converting enzyme inhibitor and lipid-lowering therapy, no history of coronary artery bypass graft, and no stress test since index myocardial infarction. A multivariate regression model for PCS-12 kept the following variables: greater number of illnesses, history of CHF or TIA, and rehospitalization since index myocardial infarction. The MCS-12 model contained age below 65 years, low overall compliance, and low compliance with lipid-lowering therapy. Further work is necessary to determine noncardiovascular predictors of quality of life and whether interventions for these patients will result in improved quality of life.

Adult↗