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Biomedical subjects

Allen J Taylor

Publications and source records attributed to Allen J Taylor.

At least 55 records · Page 3Linked to original sources
PubMed2003

The prevalence and severity of coronary artery calcification on coronary artery computed tomography in black and white subjects.

OBJECTIVES: We studied the relationship between coronary artery calcium (CAC) and race in asymptomatic, active-duty personnel in the Prospective Army Coronary Calcium (PACC) project. BACKGROUND: Valid cardiovascular risk assessments in black Americans using coronary artery computed tomography (coronary CT) require the generalizability of population-based CAC score distributions derived from primarily white patient populations. METHODS: Among 1,000 consecutive participants (mean age, 42 +/- 2 years; range, 40 to 45 years), 999 participants underwent coronary CT and indicated a specific racial affiliation. This included white, non-Hispanic in 699 (69.9%) participants and black, non-Hispanic in 194 (19.4%) participants. Univariate associations between race and cardiovascular risk variables were entered into a logistic regression model for CAC that also controlled for socioeconomic status and education. RESULTS: Coronary artery calcium was nearly twice as prevalent in white (19.2%) than in black participants (10.3%) (p = 0.004). Black individuals had a threefold greater prevalence of hypertension, left ventricular hypertrophy, ST-T-wave abnormalities, and current cigarette smoking. Black subjects also had significantly greater blood pressure, high-density lipoprotein cholesterol, glycosylated hemoglobin, lipoprotein(a) and fibrinogen levels, and lower triglyceride levels and waist girth than white subjects. After adjustment for these differences, and socioeconomic adjusters, black individuals were 39% as likely to have any CAC present (odds ratio, 0.39; 95% confidence interval, 0.20 to 0.78; p = 0.007). CONCLUSIONS: Despite a worse cardiovascular risk profile, black Americans have significantly less CAC than white Americans. The use of coronary CT as an accurate risk prediction tool in black Americans will require ethnic-specific data on the presence and severity of CAC.

Adult↗
PubMed2003

Heart failure as a cause for hospitalization in chronic dialysis patients.

BACKGROUND: Risk factors for heart failure (HF) have not been reported previously in a nationally representative sample of dialysis patients. METHODS: We conducted a historic cohort study of 1,995 patients enrolled in the US Renal Data System Dialysis Morbidity and Mortality Study Wave 2 who were Medicare eligible at the study start and were followed up until December 31, 1999, or receipt of a renal transplant. Cox regression analysis was used to model associations with time to first hospitalization for both recurrent and de novo HF (International Classification of Diseases, Ninth Revision code 428.x), defined as patients with and without a history of HF, respectively. RESULTS: The incidence density of HF was 71/1,000 person-years. Angiotensin-converting enzyme inhibitors and beta-blockers were each used in less than 25% of patients with a known history of HF. A history of coronary heart disease was associated with an increased total risk for HF, as were hemodialysis (versus peritoneal dialysis), aspirin use, and a history of diabetes. However, hemodialysis and aspirin use were the only factors associated with both de novo and recurrent HF. Widened pulse pressure was associated with de novo HF. The mortality rate after HF was 83% at 3 years (adjusted hazard ratio for mortality, 2.10; 95% confidence interval, 1.80 to 2.45; P < 0.0001). CONCLUSION: In chronic dialysis patients, hemodialysis and aspirin use were associated with increased risk for both total and de novo HF. Hospitalized HF was associated with a significantly increased risk for death.

Adrenergic beta-Antagonists↗
PubMed2003

Hospitalized atrial fibrillation after renal transplantation in the United States.

UNLABELLED: Renal transplant recipients have a high incidence of hypertension, a known risk factor for atrial fibrillation (AF), as well as factors that could increase their risk of AF. However, the incidence of, risk factors for, and mortality associated with AF after renal transplantation have not been reported. We present a historical cohort study of 39 628 renal transplant recipients in the United States Renal Data System between 1 July 1994 and 30 June 1998. DATA SOURCE: USRDS files through May 2000. Associations with hospitalizations for a primary diagnosis of AF (ICD-9 codes 427.31) after renal transplant were assessed by Cox Regression analysis. Tacrolimus was not approved for use by the FDA during the time-frame of the study. The incidence of AF after renal transplantation was 5.8 episodes/1000 person-years. In Cox Regression analysis, recipients who were older age, experienced graft loss, rejection, had higher body mass index, renal failure due to hypertension, and cyclosporine use (vs. tacrolimus use) were associated with increased risk of hospitalized AF. Atrial fibrillation was not uncommon after renal transplantation, and was associated with increased risk of mortality, primarily from cardiovascular disease. The strongest risk factors for AF after renal transplantation were older age, allograft rejection, graft loss and obesity.

Atrial Fibrillation↗
PubMed2003

Effect of atorvastatin and pravastatin on serum C-reactive protein.

BACKGROUND: Extra-lipid effects of statins, such as anti-inflammatory actions, may contribute to their clinical benefit. These effects, with important implications for the concept of a statin "class effect," may be drug specific or may be related to the extent of lipid lowering. METHODS: We randomized 130 patients to treatment with either atorvastatin (80 mg daily, n = 63) or pravastatin (40 mg daily, n = 67), and measured serum lipids, C-reactive protein, and fibrinogen at baseline and after 3 months of therapy. RESULTS: Mean C-reactive protein (CRP) levels were significantly reduced in both groups, with a 36% reduction in the atorvastatin group (0.39 +/- 0.36 to 0.25 +/- 0.27, P =.001) and a 22% reduction observed in the pravastatin group (0.40 +/- 0.33 to 0.31 +/- 0.32, P =.003). A reduced or unchanged CRP level was seen in 67.2% of pravastatin-treated patients (45/67) and 73% of atorvastatin- treated patients (46/63) (P =.47). There was no difference between drugs in either the absolute or relative reductions in CRP levels. However, whereas the reduction of CRP with pravastatin was unrelated to the degree of low-density lipoprotein reduction (r = -.05, P =.69), atorvastatin-induced CRP reductions correlated directly to the change in low-density lipoprotein-C (r =.33, P =.009). CONCLUSIONS: High-dose atorvastatin and pravastatin both reduce CRP levels. However, whereas pravastatin's effect on CRP is independent of lipid-lowering efficacy, these data suggest that lipid-dependent mechanisms are, at least in part, active in atorvastatin-treated patients.

Adult↗
PubMed2003

Early renal insufficiency and hospitalized heart disease after renal transplantation in the era of modern immunosuppression.

Renal insufficiency has been identified as a risk factor for graft loss and death after renal transplantation but has not been consistently linked to early, nonfatal, hospitalized heart disease (HHD). With the United States Renal Data System database, 29,597 patients who received a kidney transplant between January 1, 1996, and July 31, 2000, with Medicare as the primary payer, and were monitored until December 31, 2000, were studied. Cox proportional-hazards regression models were used to calculate the association of recipient estimated GFR (eGFR) at 1 yr after renal transplantation, as determined with the Modification of Diet in Renal Disease formula, with hospitalization for treatment of acute coronary syndromes (ACS) (International Classification of Diseases, version 9, code 410.x or 411.x) or congestive heart failure (CHF) (code 428.x) 1 to 3 yr after renal transplantation. Rates of ACS and CHF were 2.2 and 4.9%, respectively, for patients with eGFR of <44.8 ml/min per 1.73 m(2), compared with 1.2 and 1.4% for patients with eGFR of >69.7 ml/min per 1.73 m(2). Reduced eGFR (<44.8 ml/min per 1.73 m(2), compared with >69.7 ml/min per 1.73 m(2)) at the end of the first 1 yr after transplantation was independently associated with increased risks of both ACS (adjusted hazard ratio, 2.16; 95% confidence interval, 1.39 to 3.35) and CHF (adjusted hazard ratio, 2.95; 95% confidence interval, 2.24 to 3.90). It was concluded that early renal insufficiency (approximately stage 3 chronic kidney disease) was associated with higher rates of HHD 1 to 3 yr after kidney transplantation. Preservation of renal function after renal transplantation may reduce the rates of HHD, and renal transplant recipients with reduced eGFR should be considered at high risk of developing cardiovascular disease.

Adult↗
PubMed2003

The relationship between the 'metabolic score' and sub-clinical atherosclerosis detected with electron beam computed tomography.

BACKGROUND: This study examines the contribution of the metabolic syndrome, as defined by National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), to sub-clinical atherosclerosis and the cardiovascular risk assessment in an asymptomatic screening population. METHODS AND RESULTS: We studied 1000 consecutive, asymptomatic, apparently healthy men and women aged 40-45 years, enrolled into a prospective cardiovascular risk assessment study. The 'metabolic score' (MS) was calculated as the sum of the five metabolic syndrome risk factors defined per NCEP III. The metabolic syndrome was defined as a metabolic score >/=3. Coronary artery calcification (CAC) on electron beam computed tomography (EBCT) was used to measure sub-clinical atherosclerosis. The prevalence of the metabolic syndrome was 8.9% (89/999), and was associated with significantly higher fasting serum insulin levels and significantly lower activity indices. Participants with the metabolic syndrome were more likely to have a positive CAC score 24.7% (24 of 89) compared to those without 16.5% (159 of 910, P<0.05.) After controlling for serum low-density lipoprotein, the metabolic score and the metabolic syndrome remained a significant independent predictor of sub-clinical atherosclerosis. CONCLUSION: The 'metabolic score' is a simple clinical measurement that directly and independently relates to the likelihood of premature sub-clinical calcified atherosclerosis in an asymptomatic screening population.

Adult↗
PubMed2002

Atherosclerosis imaging to detect and monitor cardiovascular risk.

Atherosclerosis imaging techniques, such as coronary computed tomography, carotid ultrasound, and vascular magnetic resonance imaging, accurately measure the extent of subclinical atherosclerosis as a biomarker of the effects of an individual patient's coronary risk factors. Among the many potential applications of these tests, their greatest public health impact will be their use in the detection and management of cardiovascular risk. A growing body of data supports the application of these tests for the detection of cardiovascular risk, although further work is needed to document their additive diagnostic and management impact over measured risk factors and the global risk assessment. Each of these tests has a high degree of accuracy and reproducibility, creating the potential for serial imaging as a way to monitor cardiovascular risk by the detection of atherosclerosis progression, which is a known marker for an adverse cardiovascular prognosis.

Biomarkers↗
PubMed2002

ARBITER: Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol: a randomized trial comparing the effects of atorvastatin and pravastatin on carotid intima medial thickness.

BACKGROUND: Whether marked LDL reduction to levels well below 100 mg/dL would further reduce the burden of cardiovascular disease is controversial. We compared the effects of 2 statins with widely differing potencies for LDL reduction (pravastatin 40 mg/d and atorvastatin 80 mg/d) on carotid intima-media thickness (CIMT). METHODS AND RESULTS: This was a single-center, randomized, clinical trial of 161 patients (mean age, 60 years; 71.4% male; 46% with known cardiovascular disease) that met National Cholesterol Education Program (NCEP) II criteria for lipid-lowering therapy. The effects of atorvastatin (80 mg/d; n=79) and pravastatin (40 mg/d; n=82) on CIMT were compared using blinded, serial assessments of the far wall of the distal common carotid artery. Baseline CIMT and other characteristics were similar between study groups. As anticipated, atorvastatin was substantially more potent for LDL reduction after 12 months: in the atorvastatin group, LDL cholesterol was 76+/-23 mg/dL after 12 months (-48.5%); LDL cholesterol was 110+/-30 mg/dL in the pravastatin group (-27.2%; P<0.001). Atorvastatin induced progressive CIMT regression over 12 months (change in CIMT, -0.034+/-0.021 mm), whereas CIMT was stable in the pravastatin group (change of 0.025+/- 0.017 mm; P=0.03). CONCLUSIONS: Marked LDL reduction (<100 mg/dL) with a high-potency statin provides superior efficacy for atherosclerosis regression at 1 year. This early effect on CIMT, a surrogate for clinical benefit, suggests that marked LDL reduction with synthetic statins may provide enhanced reduction in clinical coronary event rates.

Adult↗
PubMed2002

Preoperative risk stratification using electron beam computed tomography in elective vascular surgery: relationship to clinical risk prediction and postoperative complications.

We studied the utility of electron beam computed tomography as a screening test for the cardiovascular risk of elective vascular surgery. In 45 patients undergoing principally carotid and aortic surgical procedures, coronary artery calcification was prevalent and severe, and related to the clinically predicted cardiovascular risk of the procedure. However, only the clinically predicted surgical risk, and not coronary artery calcification, was related to the incidence of perioperative cardiovascular complications.

Aged↗
PubMed2002

Implementation of a therapeutic-interchange clinic for HMG-CoA reductase inhibitors.

A therapeutic-interchange clinic for statins is described. In 1999, the Department of Defense mandated the use of cerivastatin and simvastatin as the formulary statins in all military health care facilities by April 2000. Cerivastatin was the preferred agent; the goal was to use this agent in 60-65% of all patients. Walter Reed Army Medical Center developed a voluntary therapeutic-interchange clinic for patients receiving statins. Goals included facilitating the rapid switching of patients to the formulary statins, maximizing the use of the preferred agent, maintaining or improving lipid control, monitoring safety, determining costs, educating patients about their treatment, and documenting satisfaction with the clinic. Written educational materials were prepared, an algorithm for statin conversion was created, and laboratory tests were performed, among other measures. Between January and April 2000, 1356 patients were seen by the therapeutic-interchange clinic; of these, 942 agreed to have the efficacy and safety of their therapy monitored by the clinic. Before the formulary change, the most commonly prescribed statins were atorvastatin (44% of patients) and pravastatin (42%). Under the conversion policy, 96% of patients received cerivastatin and 4% simvastatin. The percentage of patients achieving their targeted low-density-lipoprotein cholesterol concentration increased from 65% to 75%. The policy saved an average of $115 per patient in the first year. Most patients were satisfied with the clinic, but only 36% of providers were satisfied. Cerivastatin was withdrawn from the market in August 2001; simvastatin became the only formulary statin. A therapeutic-interchange clinic at a military medical center provided an efficient means of switching a large number of patients to alternative statin therapy, monitoring the outcomes, and individualizing patient care.

Aged↗
PubMed2002

Hospitalized congestive heart failure after renal transplantation in the United States.

PURPOSE: African Americans have increased risk for congestive heart failure (CHF) compared to Caucasians in the general population, but the risk of CHF in African American renal transplant recipients has not been studied in a national renal transplant population. METHODS: Therefore, 33,479 renal transplant recipients in the United States Renal Data System (USRDS) from 1 July, 1994 to 30 June, 1997 were analyzed in an historical cohort study of the incidence, associated factors, and mortality of hospitalizations with a primary discharge diagnosis of CHF [International Classification of Diseases-9 (ICD9) Code 428.x]. RESULTS: African American renal transplant recipients had increased age-adjusted risk of hospitalizations for congestive heart failure compared to African Americans in the general population [rate ratio 4.60, 95% confidence interval (CI) 4.59-4.62]. In logistic regression analysis, African American recipients had increased risk of congestive heart failure after renal transplantation, independent of other factors. Among other significant factors associated with congestive heart failure, the strongest were graft loss and allograft rejection. No maintenance immunosuppressive medications were associated with CHF. In Cox regression analysis patients hospitalized for CHF had increased all-cause mortality compared with all other recipients (hazard ratio 3.69, 95% CI, 2.23-6.10), but African American recipients with CHF were not at significantly increased risk of mortality compared to Caucasian recipients with CHF. CONCLUSIONS: African Americans recipients were at high risk for CHF after transplant independent of other factors. The reasons for this increased risk should be the subject of further study. All potential transplant recipients should receive particular attention for the diagnosis and prevention of CHF in the transplant evaluation process, which includes preservation of allograft function.

Adolescent↗
PubMed2002

Acute coronary syndromes after renal transplantation in patients with end-stage renal disease resulting from diabetes.

Coronary heart disease is the leading cause of death in both diabetes mellitus and end-stage renal disease. Although renal transplantation is known to reduce mortality in end-stage renal disease, its effect on the incidence of acute coronary syndromes is unknown. Using data from the United States Renal Data System, we studied 11,369 patients with end-stage renal disease due to diabetes enrolled on the renal and renal-pancreas transplant waiting list from 1 July 1994 to 30 June 1997. Cox nonproportional hazards regression models were used to calculate the adjusted, time-dependent relative risk for the most recent hospitalization for acute coronary syndromes (including acute myocardial infarction, unstable angina, or other acute coronary syndromes, ICD9 Code 410.x or 411.x) for a given patient in the study period. Demographics and comorbidities were controlled by using data from the medical evidence form (HCFA 2728). After renal transplantation, patients had an incidence of acute coronary syndromes of 0.79% per patient year, compared to 1.67% per patient year prior to transplantation. In comparison to maintenance dialysis, renal transplantation was independently associated with a lower risk for acute coronary syndromes (hazard ratio 0.38, 95% confidence interval, 0.30-0.49). Patients with end-stage renal disease due to diabetes on the renal transplant waiting list were much less likely to be hospitalized for acute coronary syndromes after renal transplantation. The reasons for this decreased risk should be the subject of further study.

Angina, Unstable↗
PubMed2002

Incident acute coronary syndromes in chronic dialysis patients in the United States.

BACKGROUND: Patients on dialysis have a disproportionately high rate of cardiovascular disease (CVD). However, the incidence and risk factors for incident acute coronary syndromes (ACS) have not been previously assessed in dialysis patients. METHODS: We analyzed the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave II in a historical cohort study of ACS. Data from 3374 patients who started dialysis in 1996 with valid follow-up times were available for analysis, censored at the time of renal transplantation and followed until March 2000. Cox regression analysis was used to model factors associated with time to first hospitalization for ACS (ICD9 code 410.x or 411.x) adjusted for comorbidities, demographic factors, baseline laboratory values, blood pressures and cholesterol levels, type of vascular access, dialysis adequacy, and cardioprotective medications (angiotensin-converting enzyme inhibitors, calcium channel blockers, HMG-CoA reductase inhibitors (statins), beta blockers, and aspirin). Follow-up was 2.19 +/- 1.14 years. RESULTS: The incidence of ACS was 29/1000 person-years. Factors associated with ACS were older age, the extreme high and low ranges of serum cholesterol level, history of coronary heart disease (CHD), male gender, and diabetes. No cardioprotective medications including statins had a significant association with ACS in this study. However, medications known to reduce mortality after ACS were used in less than 50% of patients with known CHD at the start of the study, and statins were used in less than 10% of patients with CHD. CONCLUSIONS: Dialysis patients had similar risk factors for ACS compared to the general population. Cardioprotective medications were not associated with a significant benefit, possibly due to their striking underutilization in this at-risk population.

Adult↗
PubMed2002

Physical activity and the presence and extent of calcified coronary atherosclerosis.

PURPOSE: Regular physical activity leads to a more favorable cardiovascular risk factor profile and a lower risk of developing incident coronary heart disease (CHD). These correlations suggest that higher levels of physical activity should also attenuate the presence and extent of coronary atherosclerosis. METHODS: Physical activity was measured using the Baecke Physical Activity Index in 630 consecutive asymptomatic men and women ages 39-45 without known heart disease. The degree of physical activity was compared with the cardiovascular risk factor profile and the presence and extent of subclinical atherosclerosis measured using electron beam computed tomography. RESULTS: Sports-related physical activity was associated with lower body mass index (r = -0.11; P = 0.001), higher high-density lipoprotein (HDL) cholesterol (r = 0.13; P = 0.003) and less glucose resistance as assessed by fasting serum insulin levels (r = -0.16; P = 0.001). Leisure-time and work-related physical activity were unrelated to any coronary risk variables. Calcified subclinical atherosclerosis was unrelated to all physical activity dimensions. Comparing the most sedentary (lowest quartile) and most active (highest quartile) patients, the prevalence of coronary calcium (17.0% vs 18.5%; P = 0.92) and mean coronary calcium scores (8 +/- 31 vs 5 +/- 15; P = 0.87) were similar. In a multivariate model controlling for standard cardiovascular risk factors and physical activity level, only low-density lipoprotein (LDL) cholesterol was associated with the presence of coronary calcium. CONCLUSION: Physical activity, particularly high-intensity exercise in sports-related activities, promotes a healthy cardiovascular risk profile, including lower body mass index and insulin resistance, but is unrelated to coronary calcification. This suggests that the risk reduction associated with physical activity is mediated by factors other than retarding the development of calcified atherosclerosis.

Adult↗
PubMed2002

Graft loss and acute coronary syndromes after renal transplantation in the United States.

The impact of graft loss on acute coronary syndromes (ACS) after renal transplantation has not been studied in a national population. It was hypothesized that ACS might be more frequent after graft loss, as many of the benefits of a functioning allograft on metabolism and volume regulation would be lost. Data from the 2000 United States Renal Data System (USRDS) was used to conduct an historical cohort study of ACS in 14,237 patients who received renal transplants between April 1, 1995, and June 30, 1998, (followed until April 28, 2000) with valid information from CMS Form 2728, excluding patients with hospitalized ACS before renal transplant. Cox nonproportional regression models were used to calculate the time-dependent adjusted hazard ratio (AHR) of graft loss (censored for death) for time-to-first hospitalization for ACS (International Classification of Diseases 9th Modification Diagnosis Codes [ICD9] code 410.x or 411.x) occurring after transplant. The incidence of ACS was 12.1 per 1000 patient-years (PY) in patients after graft loss versus 6.5 per 1000 PY after transplantation (excluding patients with graft loss). As a time-dependent variable, graft loss had an AHR of 2.54 (95% confidence interval, 1.09 to 5.96; P = 0.031 by Cox regression). Other risk factors associated with ACS included diabetes, older recipient, and male recipient. Allograft rejection was NS. Renal transplant recipients share some of the risk factors for ACS with the general population. In addition, graft loss was identified as a unique risk factor for ACS in this population.

Acute Disease↗
PubMed2002

Does the diagnosis of coronary calcification with electron beam computed tomography motivate behavioral change in smokers?

BACKGROUND: Electron beam computed tomography is promoted as a test that may enhance patient motivation to alter cardiovascular risk behaviors. METHODS: We surveyed a consecutive sample of asymptomatic, active smokers (N = 144) who underwent screening electron beam computed tomography about their current motivation to alter their smoking behavior in the context of their tomography results. RESULTS: Patients with coronary artery calcification (42% of the sample) were more likely to perceive increased cardiovascular risk (42 vs. 13%; p < 0.01). Overall, most patients (59%) rated themselves as more motivated to quit smoking after electron beam computed tomography, but there was no relationship between motivational levels or smoking behavioral change and the presence of coronary artery calcification. CONCLUSIONS: In smokers predominantly self-referred for electron beam computed tomography, the presence of coronary artery calcification does not appear to influence motivation for smoking cessation or smoking behavior.

Calcinosis↗