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Biomedical subjects

Thomas H Marwick

Publications and source records attributed to Thomas H Marwick.

At least 19 recordsLinked to original sources
PubMed2026

Racial outcomes in patients with diabetic cardiomyopathy treated with an aldose reductase inhibitor: the ARISE-HF trial.

BACKGROUND: Racial and ethnic differences in diabetic cardiomyopathy (DbCM) exist, with black and Hispanic participants showing poorer health status. It remains unclear whether these differences affect the natural progression of the disease. We aimed to evaluate disease progression in individuals with DbCM, as well as racial differences in the response to AT-001. METHODS: A total of 625 participants with DbCM were randomised to either placebo or AT-001 and followed for 15 months. The primary outcome was change in peak oxygen uptake (peak VO2) and secondary outcomes included Kansas City Cardiomyopathy Questionnaire (KCCQ) and Physical Activity Scale for the Elderly scores. Analyses were stratified by race and ethnicity (black, Hispanic, white). RESULTS: Black and Hispanic participants who received placebo experienced greater declines in peak VO2 (-0.74 and -1.67 mL/kg/min, respectively) compared with white participants (-0.23 mL/kg/min, p=0.005). AT-001 demonstrated a non-statistically significant trend towards slower declines in peak VO2 in black and Hispanic participants (-0.31 and -0.62 mL/kg/min, p=0.29, respectively). Black participants who received placebo had the largest declines in most KCCQ scores. CONCLUSION: Black and Hispanic participants with DbCM experienced faster disease progression, with black participants showing the most pronounced functional and quality of life declines. The effect of AT-001 on peak VO2 changes was not statistically significant with similar effects between racial and ethnic groups (NCT04083339). TRIAL REGISTRATION NUMBER: NCT04083339.

Aged↗
PubMed2007

Role of diastolic dyssynchrony in the delayed relaxation pattern of left ventricular filling.

We investigated the extent to which diastolic dyssynchrony contributes to the delayed relaxation pattern of left ventricular filling and limitation in exercise capacity. In 100 patients with diabetes, preserved left ventricular systolic function, normal filling pressure, and no coronary disease, we measured magnitude of early diastolic tissue lengthening (tissue velocity and strain rate) and diastolic dyssynchrony (SD in QRS to peak early diastolic tissue velocity interval across 4 basal myocardial segments). From transmitral flow patients were divided into those with normal filling (50 patients) and delayed relaxation (50 patients). Myocardial lengthening was reduced and SD in interval from QRS onset to peak early diastolic tissue velocity across all segments was higher in patients with delayed relaxation compared with control patients. Myocardial lengthening was the only predictor of delayed relaxation and correlation with exercise capacity was better for lengthening indices than SD in interval from QRS onset to peak early diastolic tissue velocity across all segments. Therefore, in this group a reduced rate of myocardial lengthening plays a more important role in delayed relaxation than diastolic dyssynchrony.

Adult↗
PubMed2007

Alterations in myocardial characteristics associated with obesity: detection, mechanisms, and implications.

Hypertension, obstructive sleep apnea, and coronary artery disease all contribute to the myocardial dysfunction in obesity. However, the development of sensitive cardiac imaging techniques has enabled detection of myocardial structural and functional changes independently attributable to obesity, at the preclinical stage. This review will evaluate the evidence for myocardial disease in this setting, its significance, important mechanisms, preclinical detection, and possible therapeutic implications.

Animals↗
PubMed2006

Differentiation of subendocardial and transmural infarction using two-dimensional strain rate imaging to assess short-axis and long-axis myocardial function.

OBJECTIVES: This study sought to differentiate the transmural extent of infarction (TME) by assessment of the short-axis and long-axis function of the left ventricle (LV) using 2-dimensional (2D) strain. BACKGROUND: The differentiation of subendocardial infarction from transmural infarction has significant prognostic and clinical implications. METHODS: Contrast-enhanced magnetic resonance imaging (CE-MRI) and dobutamine stress echocardiography (DBE) were performed in 80 patients (age 63 +/- 10 years) with chronic ischemic LV dysfunction. Myocardial function was assessed in the short axis at the midventricular level using peak strain rate (SR) and strain (S) in circumferential and radial dimensions, and was assessed in the long axis using longitudinal SR and S. Wall motion analysis was performed during DBE to assess for contractile reserve. RESULTS: Transmural infarct segments had lower circumferential S (-10.7 +/- 6.3) and SR (-1.0 +/- 0.4) than subendocardial infarcts (S: -15.4 +/- 7.0, p < 0.0001; SR: -1.4 +/- 0.8, p = 0.02) and normal myocardium (S: p < 0.0001; SR: p < 0.0001). Transmural and subendocardial infarct segments had similar radial S and SR. Subendocardial infarct segments showed significant reduction of longitudinal S (-13.2 +/- 5.6) and SR (-0.91 +/- 0.45) compared with normal myocardium (S: -17.8 +/- 5.4, p < 0.0001; SR: -1.1 +/- 0.41, p < 0.0001), but there were no significant differences between subendocardial and transmural infarct segments (p = 0.09). Wall motion analysis by DBE could not identify subendocardial infarction on CE-MRI (TME 1% to 50%: DBE scar 38%, DBE viable 38%, DBE ischemic 24%, p = NS). CONCLUSIONS: The combined assessment of long-axis and short-axis function using 2D strain may be used to identify TME.

Aged↗
PubMed2006

Effect of weight loss due to lifestyle intervention on subclinical cardiovascular dysfunction in obesity (body mass index >30 kg/m2).

Subclinical myocardial and vascular dysfunctions occur in subjects with obesity. We investigated whether these changes were reversible with weight loss due to lifestyle intervention. Quantitative assessment of myocardial and vascular functions was performed at baseline and after a minimum of 8 weeks of a lifestyle intervention program in 106 subjects with significant risk factors but no history of cardiovascular disease and normal ejection fractions. Myocardial function was assessed using strain rate, strain, regional myocardial systolic velocity, and diastolic velocity (e(m)). Myocardial reflectivity was assessed by calibrated integrated backscatter. Vascular function was assessed using brachial arterial reactivity and arterial compliance. Exercise capacity was measured by peak oxygen consumption per unit time (VO(2)). Weight loss (-4.5 +/- 2.0%) was achieved by 48 subjects, and 58 maintained or increased weight (+1 +/- 1.5%, p <0.001). Compared with the stable weight group, the weight loss group showed significant improvement in brachial arterial reactivity (8.6 +/- 4.9% vs 6.7 +/- 4.9%, p <0.05), e(m) (6.4 +/- 1.9 vs 5.5 +/- 1.9 cm/s, p <0.01), and reflectivity (calibrated integrated backscatter, 18.3 +/- 4.9 vs 16.2 +/- 5.2 dB, p <0.01). The magnitude of weight change correlated with changes in e(m) (r = 0.36) and calibrated integrated backscatter (r = 0.33). The change in e(m) correlated with peak VO(2) (r = 0.38, p <0.001) and was an independent predictor for peak VO(2) even after adjustment for age and body mass index in a multivariate model (R(2) = 0.45, p <0.001). Weight loss was not associated with a significant change in systolic parameters (regional myocardial systolic velocity, global strain, and strain rate) or arterial compliance.

Body Mass Index↗
PubMed2006

Aortic stenosis is associated with elevated plasma levels of asymmetric dimethylarginine (ADMA).

OBJECTIVES: We tested the hypothesis that the presence of aortic stenosis (AS) is associated with elevation of plasma levels of asymmetric dimethylarginine (ADMA), a physiological inhibitor of nitric oxide synthase, a mediator and marker of endothelial dysfunction and an indicator of incremental cardiovascular risk. BACKGROUND: The presence of aortic sclerosis (ASC), the precursor of AS is independently associated both with endothelial dysfunction, and with incremental coronary event risk. It remains uncertain whether elevations of ADMA levels might mediate endothelial dysfunction in these conditions. METHODS: Forty two consecutive patients referred for echocardiography for evaluation of AS, who had calculated aortic valve areas of <1.4 cm(2) (AS group) were evaluated together with 42 consecutive age-matched referred patients (non-AS group). Plasma ADMA levels were measured by high-performance liquid chromatography (HPLC). Determinants of elevation of plasma ADMA levels were identified via stepwise multiple linear regression analysis. RESULTS: Plasma ADMA levels were not statistically different between the AS and non-AS group (median 0.59 vs 0.54 micromol/L, p=0.13, Mann-Whitney test) on univariate analysis. However, in backward stepwise multiple linear regression, the presence of AS was a significant predictor of elevated ADMA levels (p=0.04, 95% CI=0.001, 0.072). In addition, elevated plasma ADMA levels were also associated with history of atrial fibrillation (p=0.009, 95% CI=0.015, 0.100), and negatively associated with creatinine clearance (p=0.01, 95% CI=-0.002, 0.000), and the use of statin therapy (p=0.01, 95% CI=-0.081, -0.011). CONCLUSIONS: AS is independently associated with elevation of ADMA levels, beyond that implied by "conventional" risk factors for endothelial dysfunction. The clinical status of AS as an incremental marker of cardiovascular risk may reflect ADMA-mediated endothelial dysfunction.

Aortic Valve Stenosis↗
PubMed2006

Prognostic value of intraventricular dyssynchrony according to clinical stage of left ventricular impairment.

Intraventricular dyssynchrony has prognostic implications in patients who have severe functional limitation and decreased ejection fraction. Patients with less advanced cardiac disease often exhibit intraventricular dyssynchrony, but there is little available information about its prognostic relevance in such patients. We investigated the prognostic effect of intraventricular dyssynchrony on outcome in 318 patients with known or suspected coronary artery disease who were classified according to the presence or absence of left ventricular dysfunction and heart failure symptoms. Mortality was considered the primary end point over a median follow-up of 56 months, and a Cox proportional hazards model was used for survival analysis. Despite a low prevalence (8%) of left bundle branch block, there was a high prevalence of intraventricular dyssynchrony even in patients without symptomatic heart failure. The magnitude of intraventricular dyssynchrony correlated poorly with QRS duration (r = 0.25), end-systolic volume index (r = 0.27), and number of scar segments (r = 0.25). There were 58 deaths during follow-up. Ventricular volume, ischemic burden, and magnitude of intraventricular dyssynchrony predicted outcome, but magnitude of intraventricular dyssynchrony was an independent predictor of survival only in patients with asymptomatic left ventricular dysfunction. In conclusion, patients with known or suspected coronary artery disease have a high prevalence of intraventricular dyssynchrony. Although ventricular volume, ischemic burden, and intraventricular dyssynchrony are potentially important prognostic markers, the relative importance of intraventricular dyssynchrony changes with the clinical setting and may be greatest in patients with preclinical disease.

Coronary Disease↗
PubMed2006

Incremental cost-effectiveness of exercise echocardiography vs. SPECT imaging for the evaluation of stable chest pain.

AIMS: Technological advances in cardiac imaging have led to dramatic increases in test utilization and consumption of a growing proportion of cardiovascular healthcare costs. The opportunity costs of strategies favouring exercise echocardiography or SPECT imaging have been incompletely evaluated. METHODS AND RESULTS: We examined prognosis and cost-effectiveness of exercise echocardiography (n = 4884) vs. SPECT (n = 4637) imaging in stable, intermediate risk, chest pain patients. Ischaemia extent was defined as the number of vascular territories with echocardiographic wall motion or SPECT perfusion abnormalities. Cox proportional hazard models were employed to assess time to cardiac death or myocardial infarction (MI). Total cardiovascular costs were summed (discounted and inflation-corrected) throughout follow-up. A cost-effectiveness ratio < Dollars 50,000 per life year saved (LYS) was considered favourable for economic efficiency. The risk-adjusted 3-year death or MI rates classified by extent of ischaemia were similar, ranging from 2.3 to 8.0% for echocardiography and from 3.5 to 11.0% for SPECT (model chi2 = 216; P < 0.0001; interaction P = 0.24). Cost-effectiveness ratios for echocardiography were < Dollars 20,000/LYS when the annual risk of death or MI was < 2%. However, when yearly cardiac event rate were > 2%, cost-effectiveness ratios for echocardiography vs. SPECT were in the range of Dollars 66,686-Dollars 419,522/LYS. For patients with established coronary disease (i.e. > or = 2% annual event risk), SPECT ischaemia was associated with earlier and greater utilization of coronary revascularization (P < 0.0001) resulting in an incremental cost-effectiveness ratio of Dollars 32,381/LYS. CONCLUSION: Health care policies aimed at allocating limited resources can be effectively guided by applying clinical and economic outcomes evidence. A strategy aimed at cost-effective testing would support using echocardiography in low-risk patients with suspected coronary disease, whereas those higher risk patients benefit from referral to SPECT imaging.

Aged↗
PubMed2006

Validation of a generalized transfer function to noninvasively derive central blood pressure during exercise.

Exercise brachial blood pressure (BP) predicts mortality, but because of wave reflection, central (ascending aortic) pressure differs from brachial pressure. Exercise central BP may be clinically important, and a noninvasive means to derive it would be useful. The purpose of this study was to test the validity of a noninvasive technique to derive exercise central BP. Ascending aortic pressure waveforms were recorded using a micromanometer-tipped 6F Millar catheter in 30 patients (56+/-9 years; 21 men) undergoing diagnostic coronary angiography. Simultaneous recordings of the derived central pressure waveform were acquired using servocontrolled radial tonometry at rest and during supine cycling. Pulse wave analysis of the direct and derived pressure signals was performed offline (SphygmoCor 7.01). From rest to exercise, mean arterial pressure and heart rate were increased by 20+/-10 mm Hg and 15+/-7 bpm, respectively, and central systolic BP ranged from 77 to 229 mm Hg. There was good agreement and high correlation between invasive and noninvasive techniques with a mean difference (+/-SD) for central systolic BP of -1.3+/-3.2 mm Hg at rest and -4.7+/-3.3 mm Hg at peak exercise (for both r=0.995; P<0.001). Conversely, systolic BP was significantly higher peripherally than centrally at rest (155+/-33 versus 138+/-32 mm Hg; mean difference, -16.3+/-9.4 mm Hg) and during exercise (180+/-34 versus 164+/-33 mm Hg; mean difference, -15.5+/-10.4 mm Hg; for both P<0.001). True myocardial afterload is not reliably estimated by peripheral systolic BP. Radial tonometry and pulse wave analysis is an accurate technique for the noninvasive determination of central BP at rest and during exercise.

Adult↗
PubMed2006

Comparison of two-dimensional speckle and tissue velocity based strain and validation with harmonic phase magnetic resonance imaging.

Two-dimensional (2-D) strain (epsilon2-D) on the basis of speckle tracking is a new technique for strain measurement. This study sought to validate epsilon2-D and tissue velocity imaging (TVI)-based strain (epsilonTVI) with tagged harmonic-phase (HARP) magnetic resonance imaging (MRI). Thirty patients (mean age 62 +/- 11 years) with known or suspected ischemic heart disease were evaluated. Wall motion (wall motion score index 1.55 +/- 0.46) was assessed by an expert observer. Three apical images were obtained for longitudinal strain (16 segments) and 3 short-axis images for radial and circumferential strain (18 segments). Radial epsilonTVI was obtained in the posterior wall. HARP MRI was used to measure principal strain, expressed as maximal length change in each direction. Values for epsilon2-D, epsilonTVI, and HARP MRI were comparable for all 3 strain directions and were reduced in dysfunctional segments. The mean difference and correlation between longitudinal epsilon2-D and HARP MRI (2.1 +/- 5.5%, r = 0.51, p <0.001) were similar to those between longitudinal epsilonTVI and HARP MRI (1.1 +/- 6.7%, r = 0.40, p <0.001). The mean difference and correlation were more favorable between radial epsilon2-D and HARP MRI (0.4 +/- 10.2%, r = 0.60, p <0.001) than between radial epsilonTVI and HARP MRI (3.4 +/- 10.5%, r = 0.47, p <0.001). For circumferential strain, the mean difference and correlation between epsilon2-D and HARP MRI were 0.7 +/- 5.4% and r = 0.51 (p <0.001), respectively. In conclusion, the modest correlations of echocardiographic and HARP MRI strain reflect the technical challenges of the 2 techniques. Nonetheless, epsilon2-D provides a reliable tool to quantify regional function, with radial measurements being more accurate and feasible than with TVI. Unlike epsilonTVI, epsilon2-D provides circumferential measurements.

Echocardiography↗
PubMed2006

Diastolic stress echocardiography: hemodynamic validation and clinical significance of estimation of ventricular filling pressure with exercise.

OBJECTIVES: Our study attempted to validate a Doppler index of diastolic filling (E/E') during exercise with simultaneously measured left ventricular diastolic pressure (LVDP), investigate its association with exercise capacity, and understand which patients to select for testing. BACKGROUND: The ratio of early diastolic transmitral velocity to early diastolic tissue velocity approximates LVDP at rest, but there is limited validation of exercise E/E' with invasive hemodynamic measurement, and its clinical implications are unclear. METHODS: The ratio of early diastolic transmitral velocity to early diastolic tissue velocity was measured at rest and during supine cycle ergometry in 37 patients undergoing left heart catheterization. In addition to correlation between invasive and estimated LVDP, the accuracy of different cutoffs for identification of elevated LVDP (>15 mm Hg) was determined at both rest and exercise. Doppler index of diastolic filling was also measured at rest and immediately after maximal treadmill exercise in 166 patients to investigate the association between exercise E/E' and exercise capacity (<8 metabolic equivalents [METs]). RESULTS: In patients undergoing invasive measurement, nine (24%) had elevation of LVDP only during exercise. There was a good correlation between E/E' and LVDP at rest (r = 0.67) and during exercise (r = 0.59), and the regressions at rest and exercise corresponded closely. Receiver-operator curve analysis indicated that a cutoff value of 13 for exercise E/E' identified patients with an elevated LVDP during exercise. A post-exercise E/E' >13 was highly specific (90%) for reduced exercise capacity, and even after classification of resting E/E', exercise E/E' permitted classification of patients with exercise capacity <8 METs or > or =8 METs. CONCLUSIONS: The ratio of early diastolic transmitral velocity to early diastolic tissue velocity correlates with invasively measured LVDP during exercise. It can be used to reliably identify patients with elevated LVDP during exercise and reduced exercise capacity.

Cardiac Catheterization↗
PubMed2006

Measurement of strain and strain rate by echocardiography: ready for prime time?

Strain and strain rate (SR) are measures of deformation that are basic descriptors of both the nature and the function of cardiac tissue. These properties may now be measured using either Doppler or two-dimensional ultrasound techniques. Although these measurements are feasible in routine clinical echocardiography, their acquisition and analysis nonetheless presents a number of technical challenges and complexities. Echocardiographic strain and SR imaging has been applied to the assessment of resting ventricular function, the assessment of myocardial viability using low-dose dobutamine infusion, and stress testing for ischemia. Resting function assessment has been applied in both the left and the right ventricles, and may prove particularly valuable for identifying myocardial diseases and following up the treatment response. Although the evidence base is limited, SR imaging seems to be feasible and effective for the assessment of myocardial viability. The use of the technique for the detection of ischemia during stress echocardiography is technically challenging and likely to evolve further. The clinical availability of strain and SR measurement may offer a solution to the ongoing need for quantification of regional and global cardiac function. Nonetheless, these techniques are susceptible to artifact, and further technical development is necessary.

Echocardiography↗
PubMed2006

Prevalence of heart failure and systolic ventricular dysfunction in older Australians: the Canberra Heart Study.

OBJECTIVE: To estimate the prevalence of heart failure (HF) and left ventricular (LV) systolic dysfunction in a population-based sample of older Australians. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional survey of 2000 randomly selected residents of Canberra, aged 60-86 years, conducted between February 2002 and June 2003. Participants were assessed by history, physical examination by a cardiologist, and echocardiography. MAIN OUTCOME MEASURES: Age- and sex-specific prevalence rates of clinical HF and LV systolic dysfunction (defined as LV ejection fraction < or = 50%). RESULTS: Of 1846 people eligible for our study, 1388 (75%) agreed to participate and 1275 completed all investigations (mean age, 69.4 years; 50% men). In the study sample, 72 subjects (5.6%; 95% CI, 4.4%-7.1%) had clinical HF that had been previously diagnosed and was confirmed by our assessment. A further 0.6% (95% CI, 0.3%-1.2%) had undiagnosed clinical HF (ie, evidence of structural heart disease and symptoms/signs of cardiac insufficiency without a previous diagnosis of clinical HF). Thus, the overall prevalence of clinical HF in the sample was 6.3% (95% CI, 5.0%-7.7%). Clinical HF increased in prevalence with advancing age (a 4.4-fold increase from the 60-64-years age group to the 80-86-years age group; P < 0.0001). Of the 75 subjects (5.9%; 95% CI, 4.7%-7.3%) with LV systolic dysfunction, 44 (59%) were in the preclinical stage of disease. CONCLUSION: Diagnosed HF cases represent the "tip of the iceberg" for the national burden of HF and LV systolic dysfunction. Clinically identifiable HF cases can remain undiagnosed, and the majority of people with LV systolic dysfunction are in a preclinical stage of the disease.

Age Factors↗
PubMed2006

Association of subclinical right ventricular dysfunction with obesity.

OBJECTIVES: The purpose of this research was to identify the determinants of right ventricular (RV) dysfunction in overweight and obese subjects. BACKGROUND: Right ventricular dysfunction in obese subjects is usually ascribed to comorbid diseases, especially obstructive sleep apnea. We used tissue Doppler imaging to identify the determinants of RV dysfunction in overweight and obese subjects. METHODS: Standard and tissue Doppler echocardiography was performed in 112 overweight (body mass index [BMI] 25 to 29.9 kg/m2) or obese (BMI >30 kg/m2) subjects and 36 referents (BMI <25 kg/m2), including 22 with obstructive sleep apnea but no obesity. Tissue Doppler was used to measure RV systolic (s(m)) and diastolic (e(m)) velocities and strain indexes. RESULTS: Obese subjects with BMI >35 kg/m2 had reduced RV function compared with referent subjects, evidenced by reduced s(m) (6.5 +/- 2.4 cm/s vs. 10.2 +/- 1.5 cm/s, p < 0.001), peak strain (-21 +/- 4% vs. -28 +/- 4%, p < 0.001), peak strain rate (-1.4 +/- 0.4 s(-1) vs. -2.0 +/- 0.5 s(-1), p < 0.001), and e(m) (-6.8 +/- 2.4 cm/s vs. -10.3 +/- 2.5 cm/s, p < 0.001), irrespective of the presence of sleep apnea. Similar but lesser degrees of reduced systolic function (p < 0.05) were present in overweight (BMI 25 to 29.9 kg/m2) and mildly obese (BMI 30 to 35 kg/m2) groups. Differences in RV e(m), s(m), and strain indexes were demonstrated between the severely versus overweight and mildly obese groups (p < 0.05). Body mass index remained independently related to RV changes after adjusting for age, log insulin, and mean arterial pressures. In obese patients, these changes were associated with reduced exercise capacity but not the duration of obesity and presence of sleep apnea or its severity. CONCLUSIONS: Increasing BMI is associated with increasing severity of RV dysfunction in overweight and obese subjects without overt heart disease, independent of sleep apnea.

Adult↗
PubMed2006

The diabetic myocardium.

Heart failure and diabetes mellitus are frequently associated, with diabetes potentiating the development of heart failure after other myocardial insults. This review documents the evidence in support of a specific primary myocardial disease in diabetes. The strongest clinical evidence relates to the detection of otherwise unexplained diastolic dysfunction in apparently healthy diabetic subjects, but recent studies with sensitive echocardiographic markers have shown systolic disturbances as well. The mechanism of this myocardial disease is multifactorial, with contributions from metabolic effects on the myocyte, structural changes in the myocardium and interstitium, autonomic neuropathy, and perhaps coronary vascular disease. The common pathway appears to be related to glycemic control and new evidence suggests better metabolic control to be beneficial, as well as angiotensin-converting enzyme inhibition and cross-link breakers.

Diabetes Mellitus↗
PubMed2006

Increased targeting of cardiovascular risk factors in patients with chronic kidney disease does not improve atheroma burden or cardiovascular function.

BACKGROUND: Although multiple risk factor intervention (MRFI) is recommended to reduce the increased morbidity and mortality of cardiovascular disease (CVD) in chronic kidney disease (CKD), its efficacy is unknown. We studied the efficacy of a MRFI program in CKD. METHODS: This randomized controlled study of 200 patients with stage 4 or 5 CKD compared a physician-supervised, nurse-driven MRFI clinic (focused on dyslipidemia, hyperhomocysteinemia, blood pressure [BP], anemia, and hyperphosphatemia) with conventional care in CKD. One hundred eleven subjects completed 2 years of follow-up (median follow-up 674 days [interquartile range {IQR} 348-719 days]). Outcome measures were atheroma burden (carotid intimamedia thickness [IMT]) and endothelial function (brachial artery reactivity [BAR]). RESULTS: The MRFI group showed significant improvements, compared with usual care, in serum low-density lipoprotein cholesterol (-30.9 mg/dL vs -12.7 mg/dL, P = .001), homocysteine (-6.95 vs -0.67 micromol/L, P < .001), systolic BP (-6.9 vs -0.2 mm Hg, P = .049), and diastolic BP (-4.8 vs -1.0 mm of Hg, P = .043). No significant changes were seen in serum phosphate or hemoglobin level. Despite observed improvements in risk factors, no differences from baseline were demonstrated for IMT (-0.00 vs -0.01 mm, P = .533) or BAR (0.09% vs 0.22%, P = .834). Forty-two patients reached a composite end point of CVD death, acute coronary syndrome, revascularization, nonfatal stroke, and amputation and this was similar between groups (23 vs 19 events, P = .475). CONCLUSIONS: A MRFI program was not associated with improvement in vascular structure or function in stage 4 or 5 patients with CKD.

Adult↗
PubMed2006

Risk stratification of patients with chronic kidney disease: results of screening strategies incorporating clinical risk scoring and dobutamine stress echocardiography.

BACKGROUND: Cardiac disease is the principal cause of death in patients with chronic kidney disease (CKD). Ischemia at dobutamine stress echocardiography (DSE) is associated with adverse events in these patients. We sought the efficacy of combining clinical risk evaluation with DSE. METHODS: We allocated 244 patients with CKD (mean age 54 years, 140 men, 169 dialysis-dependent at baseline) into low- and high-risk groups based on two disease-specific scores and the Framingham risk model. All underwent DSE and were further stratified according to DSE results. Patients were followed over 20 +/- 14 months for events (death, myocardial infarction, acute coronary syndrome). RESULTS: There were 49 deaths and 32 cardiac events. Using the different clinical scores, allocation of high risk varied from 34% to 79% of patients, and 39% to 50% of high-risk patients had an abnormal DSE. In the high-risk groups, depending on the clinical score chosen, 25% to 44% with an abnormal DSE had a cardiac event, compared with 8% to 22% with a normal DSE. Cardiac events occurred in 2.0%, 3.1%, and 9.7% of the low-risk patients, using the two disease-specific and Framingham scores, respectively, and DSE results did not add to risk evaluation in this subgroup. Independent DSE predictors of cardiac events were a lower resting diastolic blood pressure, angina during the test, and the combination of ischemia with resting left ventricular dysfunction. CONCLUSION: In CKD patients, high-risk findings by DSE can predict outcome. A stepwise strategy of combining clinical risk scores with DSE for CAD screening in CKD reduces the number of tests required and identifies a high-risk subgroup among whom DSE results more effectively stratify high and low risk.

Adult↗