Life-course risk factor levels and coronary artery calcification. The Cardiovascular Risk in Young Finns Study.

BACKGROUND: Risk factors measured in early life have been shown to predict coronary artery calcium (CAC) in adulthood. However, limited data exist on when risk factor profiles of those who develop CAC diverge from those who do not. We investigated the associations of coronary heart disease risk factor trajectories beginning in adolescence and CAC measured at middle-age. METHODS: CAC was measured among 589 participants aged 39-45years in whom cardiovascular risk factors (serum lipids, blood pressure, body mass index, physical activity, smoking habits, and fruit, vegetable, fish, and butter intake) had been collected in 1980, 1983, 1986, 2001, and 2007 as part of the Cardiovascular Risk in Young Finns Study. RESULTS: Mean levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol, apolipoprotein B (Apo-B), and systolic blood pressure (SBP) levels across the 27-year period were significantly higher among those with CAC vs. those without. The difference between the groups was 0.25mmol/l (95% confidence interval, 95%CI, 0.079-0.41) for LDL-C, 0.26mmol/l (95%CI 0.080-0.44) for total cholesterol, 0.05mmol/l (95%CI 0.0085-0.091) for Apo-B and 1.92mmHg (95%CI 0.10-3.74) for SBP after adjustment for other risk factors. Those with CAC at age 39-45years had higher serum lipid levels already in adolescence or early adulthood compared with those without CAC, with these differences becoming more pronounced during the life-course. CONCLUSIONS: Long-time risk factor exposure to higher LDL-C, total cholesterol and Apo-B levels already starting in adolescence and higher SBP levels in adulthood is associated with CAC at middle-age.

Coronary heart disease risk factors, coronary artery calcification and epicardial fat volume in the Young Finns Study.

AIMS: We investigated associations of pre-clinical coronary heart disease (CHD), adolescence and adulthood CHD risk factors, and epicardial fat volume (EFV), which is thought to influence CHD pathology. METHODS AND RESULTS: EFV and coronary calcium scores were quantified using computed tomography imaging for 557 subjects from the Cardiovascular Risk in Young Finns Study in 2007. CHD risk marker levels were assessed repeatedly from 1980 to 2007. Carotid intima-media thickness (cIMT), carotid distensibility, and brachial flow-mediated dilatation were measured by vascular ultrasound in 2007. Increased EFV was cross-sectionally associated with male sex, increased waist circumference, body-mass index (BMI), cIMT, metabolic syndrome prevalence, levels of apolipoprotein B, total cholesterol, low-density lipoprotein cholesterol, triglycerides, C-reactive protein, blood pressure, insulin, and fasting glucose, as well as ever smoking, alcoholic intake, and lower high-density lipoprotein cholesterol (HDL-C), carotid distensibility and physical activity in adulthood. In BMI-adjusted analyses, only apolipoprotein B, ever smoking, alcohol intake and metabolic syndrome prevalence were independently associated with EFV. In adolescence, skinfold thickness, BMI, and insulin levels were higher and HDL-C lower with increasing EFV. Subjects in the lowest vs. highest quarter of EFV had consistently lower BMI across the early life-course. CONCLUSION: Associations of CHD risk markers with EFV were attenuated after multivariable adjustment. We found no evidence of increased EFV being independently associated with pre-clinical atherosclerosis. EFV was most strongly associated with BMI and waist circumference. Subjects with higher EFV had consistently higher BMI from age 12 suggesting that life-long exposure to higher BMI influences the development of EFV.

Adolescence risk factors are predictive of coronary artery calcification at middle age: the cardiovascular risk in young Finns study.

OBJECTIVES: The purpose of this study was to examine the roles of adolescence risk factors in predicting coronary artery calcium (CAC). BACKGROUND: Elevated coronary heart disease risk factor levels in adolescence may predict subsequent CAC independently of change in risk factor levels from adolescence to adulthood. METHODS: CAC was assessed in 589 subjects 40 to 46 years of age from the Cardiovascular Risk in Young Finns Study. Risk factor levels were measured in 1980 (12 to 18 years) and in 2007. RESULTS: The prevalence of any CAC was 19.2% (27.9% in men and 12.2% in women). Age, levels of systolic blood pressure (BP), total cholesterol, and low-density lipoprotein cholesterol (LDL-C) in adolescence, as well as systolic BP, total cholesterol, diastolic BP, and pack-years of smoking in adulthood were higher among subjects with CAC than those without CAC. Adolescence LDL-C and systolic BP levels predicted CAC in adulthood independently of 27-year changes in these risk factors. The multivariable odds ratios were 1.34 (95% confidence interval: 1.05 to 1.70; p=0.02) and 1.38 (95% confidence interval: 1.08 to 1.77; p=0.01), for 1-SD increase in adolescence LDL-C and systolic BP, respectively. Exposure to both of these risk factors in adolescence (defined as values at or above the age- and sex-specific 75th percentile) substantially increased the risk of CAC (multivariable odds ratio: 3.5 [95% confidence interval: 1.7 to 7.2; p=0.007]) between groups with no versus both risk factors. CONCLUSIONS: Elevated adolescence LDL-C and systolic BP levels are independent predictors of adulthood CAC, indicating that adolescence risk factor levels play an important role in the pathogenesis of coronary heart disease.

Clinical value of absolute quantification of myocardial perfusion with (15)O-water in coronary artery disease.

BACKGROUND: The standard interpretation of perfusion imaging is based on the assessment of relative perfusion distribution. The limitations of that approach have been recognized in patients with multivessel disease and endothelial dysfunction. To date, however, no large clinical studies have investigated the value of measuring quantitative blood flow and compared that with relative uptake. METHODS AND RESULTS: One hundred four patients with moderate (30%-70%) pretest likelihood of coronary artery disease (CAD) underwent PET imaging during adenosine stress using (15)O-water and dynamic imaging. Absolute myocardial blood flow was calculated from which both standard relative myocardial perfusion images and images scaled to a known absolute scale were produced. The patients and the regions then were classified as normal or abnormal and compared against the reference of conventional angiography with fractional flow reserve. In patient-based analysis, the positive predictive value, negative predictive value, and accuracy of absolute perfusion in the detection of any obstructive CAD were 86%, 97%, and 92%, respectively, with absolute quantification. The corresponding values with relative analysis were 61%, 83%, and 73%, respectively. In region-based analysis, the receiver operating characteristic curves confirmed that the absolute quantification was superior to relative assessment. In particular, the specificity and positive predictive value were low using just relative differences in flow. Only 9 of 24 patients with 3-vessel disease were correctly assessed using relative analysis. CONCLUSIONS: The measurement of myocardial blood flow in absolute terms has a significant impact on the interpretation of myocardial perfusion. As expected, multivessel disease is more accurately detected.

Intrapericardial, but not extrapericardial, fat is an independent predictor of impaired hyperemic coronary perfusion in coronary artery disease.

OBJECTIVE: To measure intrapericardial fat (IPF), extrapericardial fat (EPF), and myocardial perfusion (MBF) in patients with and without coronary artery disease (CAD), hypothesizing that perfusion is more strongly associated with IPF because it is in direct anatomic contiguity with the myocardium or coronary arteries. METHODS AND RESULTS: Fat surrounding the heart may increase the risk of CAD and calcification, but little is known about the role of MBF in this relationship. The study included 107 patients with an intermediate likelihood of CAD. Positron emission tomography/computed tomography was used to measure IPF and EPF volumes and coronary artery calcium level, together with MBF at rest and during adenosine-induced hyperemia. Subsequently, all subjects underwent coronary angiography and were grouped for presence/absence of CAD and severity of myocardial hypoperfusion. IPF and EPF levels were higher in men and in patients with CAD (n=85) than in those without CAD (n=22) (P<0.001). EPF was increased regardless of the degree of stenoses (n=45), whereas IPF was selectively increased in subjects with obstructive stenoses (n=40). IPF and EPF levels were both associated with coronary artery calcium scores (R=0.25 and R=0.26, respectively; P<0.02), coronary flow reserve (R=-0.37 and R=-0.38, respectively; P<0.001), and hyperemic MBF (R=-0.36 and R=-0.44, respectively; P<0.0005). Male sex was a strong negative predictor of MBF. After discounting for confounders, myocardial hyperemic perfusion was predicted independently by sex, coronary artery calcium score, and IPF, but not EPF. CONCLUSIONS: CAD is accompanied by augmented fat depots surrounding the heart, which are negatively related to coronary flow hyperemia. Among fat depots, IPF was the only independent predictor of hyperemic MBF, supporting the hypothesis of a direct paracrine/vasocrine effect.

Cardiopulmonary involvement in Fabry's disease.

BACKGROUND: Fabry's disease is an X-linked lysosomal storage disease caused by deficiency of alpha-galactosidase A enzyme activity. Decreased enzyme activity leads to accumulation of glycosphingolipid in different tissues, including endothelial and smooth-muscle cells and cardiomyocytes. OBJECTIVES: There is controversial data on cardiopulmonary involvement in Fabry's disease, because many reports are based on small and selected populations with Fabry's disease. Furthermore, the aetiology of cardiopulmonary symptoms in Fabry's disease is poorly understood. METHODS: We studied cardiopulmonary involvement in seventeen patients with Fabry's disease (20-65 years, 6 men) using ECG, bicycle stress, cardiac magnetic resonance imaging, spirometry, diffusing capacity and pulmonary high-resolution computed tomography (HRCT) tests. Cardiopulmonary symptoms were compared to observed parameters in cardiopulmonary tests. RESULTS: Left ventricular hypertrophy (LVH) and reduced exercise capacity are the most apparent cardiac changes in both genders with Fabry's disease. ECG parameters were normal when excluding changes related to LVH. Spirometry showed mild reduction in vital capacity and forced expiratory volume in one second (FEV I), and mean values in diffusing capacity tests were within normal limits. Generally, only slight morphological pulmonary changes were detected using pulmonary HRCT, and they were not associated with changes in pulmonary function. The self-reported amount of pulmonary symptoms associated only with lower ejection fraction (P < 0.001) and longer QRS-duration (P = 0.04) of all measured cardiopulmonary parameters, whereas cardiac symptoms have no statistically significant association with any of these parameters. CONCLUSION: LVH and reduced exercise capacity are the most apparent cardiopulmonary changes in Fabry's disease but they have only a minor association to cardiopulmonary symptoms.Therefore, routine cardiopulmonary evaluation in Fabry's disease using echocardiography is maybe enough when integrated to counselling for aerobic exercise training.

Echocardiography in Fabry disease: diagnostic value of endocardial border binary appearance.

BACKGROUND AND AIM: It has been reported that the endocardium in Fabry disease has a binary appearance on transthoracic echocardiography. It has been suggested that this sign could be used with good accuracy to differentiate Fabry disease from hypertrophic cardiomyopathy and even as a first filter to screen for suspected Fabry disease. METHODS: Therefore, we performed a blinded echocardiography in a non-selected population of patients with Fabry disease and matched controls. We included 23 echocardiographic studies of Fabry patients. RESULTS: Two of the Fabry patients had binary appearance of the endocardium. One of them had left ventricular hypertrophy (LVH) and the other had a normal left ventricular mass. Binary appearance of the endocardium was detected in four of the controls, and one of them had LVH. Subgroup analysis of patients who had LVH indicated a sensitivity of 12.5% and a specificity of 66.7% for binary appearance of the endocardium to detect Fabry disease as the underlying cause of LVH. Overall, binary appearance of the endocardium had a sensitivity and a specificity of 15.4 and 73.3%, respectively, to distinguish patients with Fabry disease from controls in our population. CONCLUSIONS: Binary appearance of the endocardium is not feasible for screening Fabry disease by echocardiography.

Effects of cognac on coronary flow reserve and plasma antioxidant status in healthy young men.

BACKGROUND: The cardioprotective effects of certain alcoholic beverages are partly related to their polyphenol content, which may improve the vasodilatory reactivity of arteries. Effect of cognac on coronary circulation, however, remains unknown. The purpose of this randomized controlled cross-over study was to determine whether moderate doses of cognac improve coronary reactivity as assessed with cold pressor testing (CPT) and coronary flow reserve (CFR) measurement. METHODS: Study group consisted of 23 subjects. Coronary flow velocity and epicardial diameter was assessed using transthoracic echocardiography at rest, during CPT and adenosine infusion-derived CFR measurements before drinking, after a moderate (1.2 +/- 0.1 dl) and an escalating high dose (total amount 2.4 +/- 0.3 dl) of cognac. To explore the bioavailability of antioxidants, the antioxidant contents of cognac was measured and the absorption from the digestive tract was verified by plasma antioxidant capacity determination. RESULTS: Serum alcohol levels increased to 1.2 +/- 0.2 per thousand and plasma antioxidant capacity from 301 +/- 43.9 micromol/l to 320 +/- 25.0 micromol/l by 7.6 +/- 11.8%, (p = 0.01) after high doses of cognac. There was no significant change in flow velocity during CPT after cognac ingestion compared to control day. CFR was 4.4 +/- 0.8, 4.1 +/- 0.9 (p = NS), and 4.5 +/- 1.2 (p = NS) before drinking and after moderate and high doses on cognac day, and 4.5 +/- 1.4, and 4.0 +/- 1.2 (p = NS) on control day. CONCLUSION: Cognac increased plasma antioxidant capacity, but it had no effect on coronary circulation in healthy young men. TRIAL REGISTRATION: NCT00330213.

Severe coronary artery stenoses and reduced coronary flow velocity reserve in atherosclerotic mouse model: Doppler echocardiography validation study.

OBJECTIVE: Genetically modified hyperlipidemic mice are increasingly used as an animal model of atherosclerosis, but their coronary artery disease remains poorly characterized. Furthermore, non-invasive tools to detect functional consequences of coronary lesions remain to be tested in mice. Coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography provides a hemodynamic measure of coronary artery stenosis severity in humans. Thus, we applied Doppler echocardiography in atherosclerotic mice to study the relationship between CFVR and histologically determined coronary artery narrowing. METHODS: Atherosclerotic LDLR/ApoB48 double knockout mice of 58-72 weeks age (n=12) and age-matched C57BL/6 mice (n=5) were studied. CFVR was measured in anesthetized mice by Doppler echocardiography in the middle left coronary artery (LCA) during adenosine-induced maximal vasodilatation. Histopathology of proximal and middle LCA was studied in serial tissue sections. RESULTS: All LDLR/ApoB48 double knockout mice had atherosclerotic lesions in the proximal, but not in the middle LCA causing various degrees of luminal narrowing (30-97%). No lesions were found in controls. Compared with controls, CFVR was significantly reduced in the atherosclerotic mice (2.3+/-0.5 vs. 1.7+/-0.5, p=0.02). There was a negative correlation between CFVR and the amount of luminal narrowing (r=-0.91, p=0.001). Average CFVR was consistently lower in mice that had >or=70% than <70% stenosis (1.3+/-0.1, n=7 vs. 2.2+/-0.4, n=5, p=0.0002). CONCLUSIONS: LDLR/ApoB48 double knockout mice are characterized with histologically severe coronary artery narrowings. Reduced CFVR is a consistent feature of these lesions. Doppler echocardiography of coronary artery flow can be used to detect flow-limiting stenosis in living atherosclerotic mice.

A moderate dose of red wine, but not de-alcoholized red wine increases coronary flow reserve.

BACKGROUND: Red wine consumption is associated with reduced cardiovascular disease mortality. Its cardioprotective properties may be partly related to its ability to improve endothelial function. The purpose of this randomized controlled cross-over study was to determine whether moderate doses of red wine and de-alcoholized red wine improve coronary flow velocity reserve (CFR). METHODS: Using transthoracic Doppler echocardiography, 176 CFR measurements were made in 22 healthy men before and after ingestion of a moderate (4.0+/-0.4 dl) and an escalating high dose (total amount 8.1+/-0.9 dl) of alcohol-containing red wine and de-alcoholized red wine, which contained similar amounts of phenolic substances. The difference in plasma antioxidant capacity was determined by colorimetric assay kit. RESULTS: Red wine increased CFR from 3.8+/-1.4 to 4.5+/-1.4 (p<0.01) and 4.0+/-1.2 (p=NS) after moderate and high doses, respectively; whereas de-alcoholized red wine had no significant effects on CFR (4.0+/-0.7, 4.3+/-1.3 and 4.5+/-1.4, respectively). Plasma antioxidant capacity increased significantly after high dose of red wine (27.5+/-14.7%, p<0.001), but not after de-alcoholized red wine (0.5+/-10.5%, p=NS) despite similar amounts of phenolic substances. Differences between CFR and plasma antioxidant capacities before and after drinking had no significant association. CONCLUSIONS: A moderate dose of red wine, but not de-alcoholized red wine increases CFR. The increase of CFR is probably mediated by other than direct antioxidant properties of polyphenols, because the simultaneous increase of CFR and plasma antioxidant capacity were not associated.

Ambulatory blood pressure: associations with coronary heart disease in the aged Finnish population.

BACKGROUND AND AIMS: Ambulatory blood pressure (ABP) has been shown to be a better predictor of cardiovascular events than clinical blood pressure (BP) in middle-aged and older populations. This study studied the association of various components of ABP (daytime, night-time, 24-hour ABP) in the presence of coronary heart disease (CHD) in an older Finnish population. METHODS: This cross-sectional, observational, population-based study was carried out in The Lieto Health Centre, Finland, in 1998-99. The study population consisted of 502 subjects (237 men, 265 women) aged 64-87 years. ABP measurements for 24 hours, daytime (awake) and night-time (asleep), were made. Resting electrocardiograms (ECG) were recorded. A person was considered to have CHD if at least one of the following criteria was met: (I) history of coronary by-pass surgery or coronary angioplasty, (II) diagnosis of CHD in previous medical records, (III) ischemia-related changes on ECG. RESULTS: CHD increased by 30% with a 10 mmHg increase in night-time systolic blood pressure (SBP) (OR 1.30, 95% Cl 1.15-1.47). When ambulatory 24-hour and daytime SBP values were each entered separately into the multivariate model, 24-hour SBP, but not daytime SBP, was associated with CHD. CONCLUSIONS: The most important information gained from 24-h BP monitoring in subjects with CHD is night-time BP. Night-time BP may provide new information about the CHD risk which is not identified in common clinical diagnoses of hypertension. ABP measurements should be made to confirm sufficient control of night-time BP, especially SBP, in older people with CHD.

Vasodilation of epicardial coronary artery can be measured with transthoracic echocardiography.

Transthoracic Doppler echocardiography (TTE) has been introduced as a noninvasive tool to measure coronary flow velocity reserve (CFVR). Velocity measurement, however, fails to take into account epicardial coronary artery vasodilation during hyperemia and this may cause underestimation of CFVR measurements. Therefore, we sought to determine whether the vasodilation of epicardial coronary artery can be measured during cold pressor test (CPT) and adenosine infusion simultaneously with the flow velocity measurement using TTE. We studied 41 healthy nonsmoking men with a linear high-frequency 8.0-MHz transducer. The CPT and adenosine infusion dilated the diameter of the distal left anterior descending coronary artery (LAD) from 1.4 +/- 0.4 mm to 1.5 +/- 0.4 mm (14 +/- 13%, p < 0.01) and from 1.4 +/- 0.4 mm to 1.8 +/- 0.5 mm (31 +/- 19%, p < 0.01), respectively. The CPT increased flow velocity and calculated coronary blood flow rate (velocity time integral x cross-sectional area) from 0.23 +/- 0.05 m/s to 0.36 +/- 0.13 m/s (31 +/- 34%, p < 0.01) and from 8.1 +/- 4.2 mL/min to 11.4 +/- 6.0 mL/min (47 +/- 51%, p < 0.01). CFVR and calculated coronary blood flow rate reserve were 3.9 +/- 1.0 and 6.0 +/- 1.9, respectively. In Bland-Altman analysis, velocity measurements underestimated the vasodilation response of the CPT and adenosine compared with the measurements where epicardial diameter dilation was taken into account. Intra- and interobserver variability of diameter measurements was low (coefficient of variation [CV] 2.6 to 6.5%). Day-to-day, within-day and intersonographer variabilities were of similar magnitude (CV 4.6 to 8.2%), suggesting good reproducibility. This study demonstrates that TTE can be used to assess changes in both epicardial coronary artery diameter and flow velocity simultaneously in the distal LAD artery.

Long-term alterations of heart rate dynamics after coronary artery bypass graft surgery.

We tested the hypothesis that there may be long-term alterations in overall heart rate (HR) variability and in fractal HR behavior after coronary artery bypass graft (CABG) surgery. Reduced HR variability predicts morbidity in various patient populations. Continuous 24-h electrocardiograph recordings were performed in 25 elective CABG surgery patients 1 wk before the operation and 6 wk and 6 mo after. Seventeen of the patients also had recordings 12 mo after CABG. Time and frequency domain measures of HR variability were assessed, along with measurement of short-term fractal scaling exponent (alpha1), approximate entropy, and power-law relationship of relative risk interval variability (beta-slope). The high, low, very low, and ultra low frequency powers decreased significantly after the operation and remained at a significantly decreased level 6 wk and 6 and 12 mo after the operation than before (P = 0.01, P < 0.001, P < 0.001, and P < 0.001 for overall difference between the time points, respectively). The fractal scaling exponent alpha1 was at significantly more decreased 6 wk after (P < 0.05) CABG than before surgery but recovered to the preoperative level 6 mo after the operation. Long-term fractal organization (beta-slope) remained stable, but the overall complexity (approximate entropy) decreased toward more predictable HR dynamics during the study period (P < 0.01 after 1 yr). The predictive value of temporary and persistent long-term changes of the HR dynamics after CABG surgery for long-term outcome is not clear.

Coronary flow reserve and heart failure in experimental coxsackievirus myocarditis. A transthoracic Doppler echocardiography study.

The objective of this study was to apply transthoracic Doppler echocardiography (TTDE) in mice to study coronary flow reserve (CFR), an index of coronary microvascular function, in mild and severe forms of experimental viral myocarditis. Regarding methodology, BALB/c mice were infected with cardiotropic coxsackieviruses causing either a mild (Nancy strain) or a severe (Woodruff strain) myocarditis. Left ventricular dimensions, fractional shortening, and CFR (ratio of left coronary artery flow velocity during maximal adenosine-induced vasodilatation to rest) were measured by TTDE before infection and again 1 or 2 wk after infection. As a result, the resting flow velocity did not change after infection. In contrast, CFR reduced significantly 1 wk after infection with either virus variant [from 2.5 (SD 0.3) to 1.4 (SD 0.1) in severe and from 2.4 (SD 0.4) to 2.1 (SD 0.3) in mild myocarditis], being significantly lower in the severe than mild myocarditis. CFR remained low in severe myocarditis 2 wk after infection. Fractional shortening decreased to the same levels 1 wk after infection with either virus variant [from 0.54 (SD 0.02) to 0.43 (SD 0.03) in severe and from 0.51 (SD 0.03) to 0.44 (SD 0.02) in mild myocarditis, P < 0.05]. However, 2 wk after infection, mice with severe myocarditis had enlarged left ventricles and lower fractional shortening [0.31 (SD 0.03)] than mice with mild myocarditis [0.47 (SD 0.02), P < 0.01]. In conclusion, CFR measured with TTDE is reduced in coxsackievirus myocarditis in mice. Low CFR is associated with progressive heart failure, indicating that dysfunction of coronary microcirculation is a determinant of poor outcome in viral myocarditis.

Determinants of coronary flow velocity reserve in healthy young men.

The objective of this study was to identify risk markers for attenuated coronary flow velocity reserve (CFVR) that exist in healthy young men without evident atherosclerotic risk factors. Coronary blood flow velocity was measured with transthoracic Doppler echocardiography at baseline and during adenosine infusion in 37 healthy nonsmoking men [mean age, 27 yr (SD 4.0)]. Body composition and distribution of fat tissue were assessed with anthropometric measures and regulation of fat metabolism by determination of adiponectin and leptin levels. Physical performance capacity was tested with ergospirometry. The mean body mass index was 23 kg/m2 (SD 1.9), waist-to-hip ratio was 0.84 (SD 0.04), and CFVR was 3.5 (SD 0.61). Obesity indexes at study outset, leptin, adiponectin, maximal load (Max load in W/kg) and maximal oxygen consumption (Vo2 peak in ml x kg(-1) x min(-1)) in ergospirometry, rate-pressure product, and heart rate at rest were significantly associated with CFVR. In multivariate analysis, Max load (in W/kg) and waist-to-hip ratio were the only independent predictors of CFVR. We found no relationship between CFVR and serum lipids or body mass index. We conclude that abdominal fat accumulation and low aerobic fitness are independently associated with CFVR in men.

The breakdown of fractal heart rate dynamics predicts prolonged postoperative myocardial ischemia.

UNLABELLED: Patients with myocardial ischemia after noncardiac surgery have a three- to ninefold increased risk of adverse cardiac events. In this study we tested the hypothesis that altered preoperative heart rate variability (HRV) predicts postoperative prolonged myocardial ischemia (>10 min) in elderly surgical patients. Thirty-two patients, age 60 yr or older, admitted to hospital for surgical repair of a traumatic hip fracture with preoperative night and daytime Holter recordings were included. Holter monitoring was initiated at arrival at hospital and continued until the third postoperative morning. Conventional HRV measures along with analysis of short-term fractal scaling exponent (alpha(1)) of RR intervals were assessed for night (from 2 AM to 5 AM) and day (7 AM to 12 AM) periods in each patient. Preoperative alpha(1) was significantly lower (i.e., increased randomness in HRV) during the nighttime compared with daytime (mean +/- SEM; 0.92 +/- 0.08 versus 1.03 +/- 0.06; P = 0.002) in patients with postoperative myocardial ischemia. Patients without ischemia had no such difference. In stepwise multivariate logistic regression analysis, increased preoperative night-day difference of alpha(1) was the only independent predictor of postoperative prolonged ischemia. The odds ratio for an increase of 0.16 U in night-day difference of alpha(1) (corresponding to interquartile range) was 7.7 (95% confidence interval, 1.9-51.4; P = 0.0018). Breakdown of fractal-like heart rate dynamics is predictive for postoperative prolonged myocardial ischemia in elderly patients having emergency surgery for traumatic hip fracture. IMPLICATIONS: Night and daytime Holter recordings before surgical repair of traumatic hip fracture were analyzed with linear and nonlinear heart rate variability methods. Preoperatively increased randomness in heart rate variability was predictive for postoperative, silent prolonged myocardial ischemia. Prolonged myocardial ischemia increases the risk for adverse cardiac events.

Weight reduction with very-low-caloric diet and endothelial function in overweight adults: role of plasma glucose.

OBJECTIVE: Obesity is associated with endothelial dysfunction that may contribute to the development of atherosclerosis. We studied whether weight reduction improves endothelial function in overweight individuals. METHODS AND RESULTS: Flow-mediated endothelium-dependent vasodilation of the brachial artery was measured in 67 adults (age: 46+/-7 years, body mass index: 35.2+/-5.4 kg/m2) before and after a 6-week weight reduction program induced by very-low-calorie diet (daily energy: 580 kcal/2.3 MJ). Caloric restriction reduced body weight from 101+/-18 to 90+/-17 kg. Flow-mediated vasodilation increased from 5.5%+/-3.7 to 8.8%+/-3.7% (P<0.0001). Nitrate-mediated vasodilation was not significantly affected. The improvement in flow-mediated dilation was associated with the reduction in plasma glucose concentration (P=0.0003). This relationship was independent of changes in weight, serum lipids, oxidized LDL, C-reactive protein, adiponectin, blood pressure, and insulin. CONCLUSIONS: Weight reduction with very-low-calorie diet improves flow-mediated vasodilation in obese individuals. This improvement is related to the reduction in plasma glucose concentration. These observations suggest that changes in glucose metabolism may determine endothelial vasodilatory function in obesity.

Relation of heart rate dynamics to the occurrence of myocardial ischemia after coronary artery bypass grafting.

Postoperative myocardial ischemia is a common finding after coronary artery bypass grafting (CABG) and is associated with an adverse short-term clinical outcome. The reasons and pathophysiologic background for the occurrence of ischemia after CABG are not well established. We tested the hypothesis that altered heart rate (HR) behavior precedes the onset of myocardial ischemic episodes in patients after CABG. Time-domain HR variability measurements, along with analysis of Poincaré plots and fractal scaling analysis were assessed in 40 CABG patients from 48-hour postoperative Holter recordings. Twenty patients experienced 195 ischemic episodes during the postoperative course. In the univariate analysis of HR variability measurements of the first postoperative day (POD), the increased ratio between the short-term (SD1) and long-term (SD2) HR variability analyzed from the Poincaré plot and the decreased short- and intermediate-term fractal scaling exponents alpha(1) and alpha(2) were significantly associated with ischemia during the study period (p <0.01, p <0.05, and p <0.05, respectively). In the multivariate model, the increased SD1/SD2 ratio of the first POD was the most powerful independent predictor of all possible confounding variables for the occurrence of postoperative ischemia (corresponding to a change of 0.15 U; odds ratio 2.2 and 95% confidence interval 1.2 to 5.7; p <0.01). Altered HR dynamics have been associated with myocardial ischemic episodes in patients after CABG, suggesting that the autonomic nervous system has an important role in the pathogenesis of myocardial ischemia in the postoperative phase of CABG.