Non-diabetic hyperglycaemia correlates with angiographic coronary artery disease prevalence and severity.

AIM: The role of glycaemia as a coronary artery disease (CAD) risk factor is controversial, and the optimal glucose level is still a matter of debate. For this reason, we assessed the prevalence and severity of angiographic CAD across hyperglycaemia categories and in relation to haemoglobin A(1c) (HbA(1c)) levels. METHODS: We studied 273 consecutive patients without prior revascularization undergoing coronary angiography for suspected ischaemic pain. CAD severity was assessed using three angiographic scores: the Gensini's score; extent score; and arbitrary index. Patients were grouped, according to 2003 American Diabetes Association criteria, into those with normal fasting glucose (NFG), impaired fasting glucose (IFG) and diabetes mellitus (DM). RESULTS: CAD prevalence was 2.5-fold higher in both the IFG and DM groups compared with the NFG group. Deterioration of glycaemic profile was a multivariate predictor of angiographic CAD severity (extent score: P=0.027; arbitrary index: P=0.007). HbA(1c) levels were significantly higher among CAD patients (P=0.016) and in those with two or more diseased vessels (P=0.023) compared with the non-CAD group. HbA(1c) levels remained predictive of CAD prevalence even after adjusting for conventional risk factors, including DM (adjusted OR: 1.853; 95% CI: 1.269-2.704). CONCLUSION: Non-diabetic hyperglycaemia, assessed either categorically by fasting glucose categories or continuously by HbA(1c) levels, correlates with the poorest angiographic outcomes.

Systems biology in heart diseases.

Systems biology based on integrative computational analysis and high technology is in a position to construct networks, to study the interactions between molecular components and to develop models of cardiac function and anatomy. Clinical cardiology gets an integrated picture of parameters that are addressed to ventricular and vessel mechanics, cardiac metabolism and electrical activation. The achievement of clinical objectives is based on the interaction between modern technology and clinical phenotype. In this review the need for more sophisticated realization of the structure and function of the cardiovascular system is emphasized while the incorporation of the systems biology concept in predicting clinical phenotypes is a promising strategy that optimize diagnosis and treatment in cardiovascular disease.

Aortic arch calcification predicts the extent of coronary atherosclerosis in patients with or without type 2 diabetes: short communication.

AIM OF THE STUDY: The aim of this study was to evaluate the sensitivity and specificity of aortic arch calcification for detection of severe coronary atherosclerosis in patients suffering from coronary artery disease (CAD), with or without type 2 diabetes. PATIENTS AND METHODS: This study included 107 type 2 diabetic patients (68 men) with a mean age of 62.4 +/- 10.7 years and a mean diabetes duration of 14.2 +/- 5.9 years and 104 patients (63 men) with a mean age of 64.5 +/- 9.3 years who did not have diabetes. All patients had CAD, documented by coronary arteriography. Severe CAD was defined as atherosclerosis of the left main branch or atherosclerosis of three coronary arteries or atherosclerosis of the proximal part of the left anterior descending artery. Aortic arch calcification was assessed by means of posteroanterior chest X-rays, studied by a radiologist kept blind to the result of coronary arteriography. RESULTS: In type 2 diabetic patients, diagnosis of aortic arch calcification had 65.6% sensitivity and 86.9% specificity for detection of severe CAD. In patients without diabetes, diagnosis of aortic arch calcification had 47.7% sensitivity and 96.7% specificity for detection of severe CAD. CONCLUSIONS: Aortic arch calcification has a high specificity for detection of severe coronary atherosclerosis in patients with CAD. Sensitivity is higher in patients with type 2 diabetes, while specificity is slightly higher in non-diabetic patients.

Revisiting the frequency of peripheral arterial disease in patients with coronary artery disease: is there a difference between diabetic and non-diabetic patients?

BACKGROUND: The aim of this study was to investigate whether frequency of concomitant peripheral arterial disease (PAD) is associated with angiographic severity of coronary artery disease (CAD), as well as to ascertain if diabetic patients differ from those without diabetes in the association between these two manifestations of atherosclerosis. PATIENTS AND METHODS: This study included 302 patients (229 men, mean age 62.2 +/- 11.5 years) with documented CAD, divided into groups I-III, according to the angiographic severity of coronary atherosclerosis. Group I comprised 140 patients (104 men) with severe CAD, group II comprised 63 patients (48 men) with moderate CAD and group III comprised 99 patients (77 men) with mild CAD. Each of the groups I-III was further divided into the subgroups of diabetic and non-diabetic patients. Included were also 88 patients (42 men, mean age 61.7 +/- 9.5 years) without CAD and a control group of 60 healthy volunteers (30 men), aged 18-40 years. PAD was diagnosed by means of a Doppler apparatus. RESULTS: Frequency of PAD was associated with angiographic severity of CAD (p = 0.0001). This association was shown both in diabetic (p = 0.012) and in non-diabetic patients (p = 0.0041). Significantly (p < or = 0.01) higher frequency of PAD among diabetic patients was found in each of the groups I-III. CONCLUSIONS: Among patients with CAD, frequency of concomitant PAD is associated with angiographic severity of coronary atherosclerosis. This association is demonstrated both in diabetic and in non-diabetic patients. Finally, PAD is significantly more frequent in diabetic patients, irrespective of the angiographic severity of CAD.

Predicting the risk of rupture of abdominal aortic aneurysms by utilizing various geometrical parameters: revisiting the diameter criterion.

The authors estimated noninvasively the wall stress distribution for actual abdominal aortic aneurysms (AAAs) in vivo on a patient-to-patient basis and correlated the peak wall stress (PWS) with various geometrical parameters. They studied 39 patients (37 men, mean age 73.7 +/- 8.2 years) with an intact AAA (mean diameter 6.3 +/- 1.7 cm) undergoing preoperative evaluation with spiral computed tomography (CT). Real 3-dimensional AAA geometry was obtained from image processing. Wall stress was determined by using a finite-element analysis. The aorta was considered isotropic with linear material properties and was loaded with a static pressure of 120.0 mm Hg. Various geometrical parameters were used to characterize the AAAs. PWS and each of the geometrical characteristics were correlated by use of Pearson's rank correlation coefficients. PWS varied from 10.2 to 65.8 N/cm2 (mean value 37.1 +/- 9.9 N/cm2). Among the geometrical parameters, the PWS was well correlated with the mean centerline curvature, the maximum centerline curvature, and the maximum centerline torsion of the AAAs. The correlation of PWS with maximum diameter was nonsignificant. Multiple regression analysis revealed that the mean centerline curvature of the AAA was the only significant predictor of PWS and subsequent rupture risk. This noninvasive computational approach showed that geometrical parameters other than the maximum diameter are better indicators of AAA rupture.

Usefulness of colour tissue Doppler imaging in assessing aortic elastic properties in Type 1 diabetic patients.

AIMS: Diabetes mellitus (DM) is associated with macrovascular disease and impaired aortic function. We hypothesized that the change in aortic elastic properties could be investigated with colour tissue Doppler imaging (CTDI) in Type 1 diabetic patients and that these findings could be related to the aortic stiffness index. METHODS: We examined by echocardiography 66 patients with Type 1 DM (mean age 35 +/- 10 years, mean duration of disease 20 +/- 9 years) without a history of arterial hypertension or coronary artery disease (negative thallium-201 stress test) and 66 age- and sex-matched normal subjects. Arterial pressure was measured before echocardiography was performed. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic systolic upper wall tissue velocity (Sao, cm/s) by CTDI were measured 3 cm above the aortic valve. Aortic distensibility and aortic stiffness index were calculated using accepted formulae. RESULTS: Aortic stiffness, distensibility and Sao velocity differed significantly between the studied groups. In the diabetic group, duration of diabetes correlated with aortic stiffness (r = 0.53, P < 0.001), distensibility (r = -0.61, P < 0.001) and Sao velocity (r = -0.48, P < 0.001). There was a negative correlation between aortic stiffness and Sao velocity (r = -0.49, P < 0.001). Multiple stepwise linear regression analysis in the diabetic group revealed that aortic S velocity (beta = 0.30, P = 0.005) and duration of diabetes (beta = -0.49, P = 0.001) were the main predictors of aortic distensibility (overall R(2) = 0.48). CONCLUSIONS: Aortic elastic properties can be directly assessed by measuring the movements in the upper aortic wall. Reduced aortic S velocity is associated with increased aortic stiffness in Type 1 diabetic patients.

In-hospital and long-term prognostic value of fibrinogen, CRP, and IL-6 levels in patients with acute myocardial infarction treated with thrombolysis.

Plasma fibrinogen, C-reactive protein (CRP), and interleukin-6 (IL-6) levels in patients with acute myocardial infarction (AMI) receiving thrombolysis have been related to prognosis. The aim of this study was to investigate the time course of plasma fibrinogen, CRP, and IL-6 levels during the in-hospital phase in patients with AMI receiving thrombolysis, and their relationship to in-hospital and prognosis after 12-months follow-up. In 40 patients presenting with AMI within 6 hours of symptom onset and treated with thrombolysis, plasma fibrinogen, CRP, and IL-6 levels were measured on admission and after 6, 12, 24, 48, and 72 hours; 7 days; and 6 months. Patients with other diseases that can alter fibrinogen, CRP, or IL-6 levels were excluded. Patients had a clinical follow-up at 6 and 12 months, and the following cardiac events were recorded: cardiac death, recurrent angina, recurrent AMI, and heart failure. Plasma fibrinogen concentrations decreased significantly (p <0.01 vs admission levels) at 12 hours (425 +/-94 vs 322 +/-132 mg/dL), started to increase at 24 hours, reached peak value at 72 hours (602 +/-209 mg/dL), remained elevated at 7 days, and were back to admission levels at 6 months (375 +/-79 mg/dL). CRP levels increased significantly at 12 hours (0.73 +/-0.43 vs 0.23 +/-0.11 mg/dL, p <0.01), reached peak value at 72 hours (7.66 +/-3.28 mg/dL), decreased significantly on day 7 (2.32 +/-1.17 mg/dL), and at 6 months were within normal limits (0.49 +/-0.29 mg/dL). IL-6 levels increased significantly at 6 hours (14.03 +/-8.13 vs 6.37 +/-3.88 pg/mL, p <0.05), reached peak value at 24 hours (59.49 +/-23.57 pg/mL), started to decrease at 48 hours, and at 6 months were within normal limits (2.25 +/-1.24 pg/mL). During the in-hospital phase 33 patients had an uneventful course and 7 patients had complications (3 post-AMI angina; 4 heart failure). During the 12-month follow-up period 28 patients had an uneventful course, and 12 patients had complications (1 cardiac death, 5 recurrent angina, 2 recurrent AMI, and 4 heart failure). Regarding the in-hospital prognosis, fibrinogen, CRP, and IL-6 levels were significantly higher (p <0.05) in patients with complications from 48 to 72 hours, from 12 hours until day 7, and from 6 hours until day 7, respectively. During the 12-month follow-up period fibrinogen, CRP, and IL-6 levels were significantly higher in patients with complications (at 48, 24, and 24 hours, respectively) only in the subgroup of patients who had complications within the first 6 months following AMI. Multivariate analysis showed that CRP at 48 hours was the most important factor related to in-hospital prognosis (p = 0.02), and ejection fraction followed by CRP at 24 hours (p = 0.02) to 6-month prognosis (p = 0.018). Fibrinogen, CRP, and IL-6 levels alter in patients with AMI receiving thrombolysis, and are related both to in-hospital and to 6-month follow-up prognosis.

Risk factors for concomitant peripheral arterial occlusive disease in patients with coronary artery disease: is there a difference between diabetic and non-diabetic patients?

AIM OF THE STUDY: The aim of the present study was investigation of cardiovascular risk factors for concomitant Peripheral Arterial Occlusive Disease (PAOD) in diabetic vs. non-diabetic patients with coronary artery disease (CAD). PATIENTS AND METHODS: This study included 302 patients (229 men) with a mean age of 62.2 +/- 11.5 years and angiographically documented CAD. These were divided into Group A comprising 116 diabetic patients (79 men) and Group B comprising 186 non-diabetic patients (150 men). Peripheral Arterial Occlusive Disease (PAOD) was diagnosed using a Doppler apparatus. Cardiovascular risk factors that were investigated included age, history of myocardial infarction, smoking, Body-Mass Index, Waist-Hip-Ratio, hypertension and serum lipids. RESULTS: PAOD was diagnosed in 49 patients of Group A (42.4%) and 20 patients of Group B (10.8%). In Group A concomitant PAOD was associated with significantly (p = 0.0001) longer diabetes duration and significantly (p = 0.0001) higher frequency of insulin treatment, as well as significantly (p = 0.02) higher triglycerides and significantly (p = 0.039) lower HDL-Cholesterol. In Group B patients with PAOD had significantly (p = 0.0001) higher age and significantly higher (p = 0.041) LDL-Cholesterol levels than those without PAOD. No association was found between PAOD and presence of remaining risk factors in either group. In multiple regression analysis, concomitant PAOD was associated with diabetes duration (p = 0.0026) and insulin treatment (p = 0.0004) in Group A, while it was associated with age (p = 0.01) in Group B. The associations with serum lipids were no longer significant. CONCLUSIONS: Among non-diabetic patients with CAD, those who have concomitant PAOD are significantly older. Among diabetic patients with CAD, those who have concomitant PAOD show significantly longer diabetes duration and significantly higher frequency of insulin treatment.

Impact of diabetes mellitus on severity of concomitant peripheral arterial occlusive disease in patients with coronary artery disease.

AIM OF THE STUDY: The aim of the study was to evaluate the impact of Diabetes Mellitus (DM) on severity of concomitant Peripheral Arterial Occlusive Disease (PAOD) in patients with Coronary Artery Disease (CAD). PATIENTS AND METHODS: This study included 302 patients (229 men) with a mean age of 62.2 +/- 11.5 years who had angiographically documented CAD. Patients were divided into Group I (severe CAD), Group II (moderate CAD) and Group III (mild CAD). Each of the groups I-III was divided into subgroups comprising diabetic patients (subgroups Ia, IIa, IIIa) and non-diabetic patients (subgroups Ib, IIb, IIIb). PAOD was evaluated by measurement of Toe-Brachial Index (TBI). RESULTS: PAOD was diagnosed in 69 patients (22.8%). Symptoms of PAOD (intermittent claudication or rest pain) were present in 38 patients (55%), while 31 patients (45%) were asymptomatic. Frequency of symptoms attributable to PAOD did not differ (p = 0.43) between diabetic patients (25 out of 49 patients, 51%) and non-diabetic patients (13 out of 20 patients, 65%). TBI was significantly (p = 0.04) lower in diabetic (0.41 +/- 0.03) than in non-diabetic patients with PAOD (0.51 +/- 0.03). This significant difference was found in each of the Groups I-III. Severity of PAOD was significantly associated with angiographic gravity of CAD, both in diabetic (p = 0.046) and in non-diabetic patients (p = 0.047). CONCLUSIONS: DM has an adverse impact on severity of concomitant PAOD in patients with CAD. This impact does not depend on angiographic gravity of CAD. However, the association between severity of PAOD and angiographic gravity of CAD is demonstrated both in diabetic and in non-diabetic patients.

Detection of myocardial viability by dobutamine stress echocardiography: incremental value of diastolic wall thickness measurement.

OBJECTIVE: To assess the diagnostic accuracy of baseline diastolic wall thickness (DWT) alone and as an adjunct to dobutamine stress echocardiography (DSE) for prediction of myocardial viability in patients with ischaemic left ventricular (LV) dysfunction, with the recovery of resting function after revascularisation as the yardstick. PATIENTS: 24 patients with ischaemic LV dysfunction (ejection fraction < 40%) scheduled for surgical revascularisation. SETTING: Regional cardiothoracic centre. METHODS: All patients underwent DSE before and resting echocardiography six months after revascularisation. DWT was measured in each of the 16 LV segments. A receiver operating characteristic (ROC) and a multi-ROC curve were generated to assess the ability of DWT alone and in combination with DSE to predict myocardial viability. RESULTS: DWT > 0.6 cm provided a sensitivity of 80%, a specificity of 51%, and a negative predictive value of 80% for the prediction of viability in akinetic segments. DSE had an excellent specificity (92%) but a modest sensitivity (60%) in akinetic segments. A combination of improvement at DSE or DWT > 0.8 cm improved sensitivity (90% v 60%, p < 0.001) and negative predictive value (92% v 78%, p = 0.03) in akinetic segments compared with DSE alone. This was achieved with some loss in specificity (75% v 92%, p = 0.01) and positive predictive value (71% v 82%, p = 0.79). CONCLUSIONS: DWT measurement may improve the sensitivity of DSE for the detection of myocardial viability. Akinetic segments with DWT > 0.8 cm have a good chance of recovery despite the absence of contractile reserve during DSE. Further testing may be required before excluding myocardial viability in these cases.

Peripheral arterial occlusive disease as a predictor of the extent of coronary atherosclerosis in patients with coronary artery disease with and without diabetes mellitus.

We evaluated the sensitivity and specificity of a diagnosis of peripheral arterial occlusive disease (PAOD) as a predictor of the severity of coronary artery disease (CAD) in patients with and without diabetes. A total of 302 patients were assigned to groups according to the angiographic severity of their CAD and their diabetes status. Both PAOD and severe PAOD were diagnosed by measuring the ankle-brachial index (ABI) and toe-brachial index (TBI). A diagnosis of PAOD had a low sensitivity (34.3%) but a high specificity (87.0%) for detecting patients with severe CAD. Sensitivity was higher in patients with diabetes (52.4%) than without (19.5%), whereas specificity was higher in patients without diabetes (95.4%) than those with diabetes (69.8%). A diagnosis of severe PAOD had a higher specificity (96.0%), but a very low sensitivity (16.4%). We conclude that a diagnosis of PAOD among patients with CAD had a low sensitivity but a high specificity for detecting those with severe CAD, particularly in patients without diabetes.

Wigner-Ville analysis and classification of electrocardiograms during thrombolysis.

Non-stationary analysis of electrocardiograms (ECGs) using Wigner-Ville distribution is presented. Analysis was performed on subjects with acute myocardial infarction who had undergone thrombolysis, in Holter recordings of lead V1. The distinction between successfully and non-successfully thrombolysed patients was evaluated, based on time-frequency features of the Wigner-Ville transformed ECGs at the sixth hour after lysis. Characteristic parameters were extracted from time-frequency areas, and linear discriminant analysis was performed on these parameters, leading to a prediction index to distinguish the two classes. Thirteen features were found statistically significant by t-test and were used for the classification with linear modelling. Out of these features, four corresponded to frequencies lower than 25 Hz and higher than 50 Hz for, roughly, the QRS complex, five features corresponded to all the frequency bands of, roughly, the ST area, and the last four features corresponded to the T-wave. The feature-vector used in linear modelling was iteratively generated, and the iterative prediction found all 18 features significant. The iterative method resulted in better classification than that of the standard statistical procedure (3.8% error against 18.1% with the classic method). The evolution of the prediction index with time for the first 12 h was different for the successfully and non-successfully thrombolysed groups. Specifically, in the successful thrombolysis group, oscillations and variation with time were more obvious, indicating a possible difference in the dynamics of the cardiac system.

Home care delivery through the mobile telecommunications platform: the Citizen Health System (CHS) perspective.

Health delivery practices are shifting towards home care. The reasons are the better possibilities for managing chronic care, controlling health delivery costs, increasing quality of life and quality of health services and the distinct possibility of predicting and thus avoiding serious complications. For the above goals to become routine, new telemedicine and information technology (IT) solutions need to be implemented and integrated in the health delivery scene, and these solutions need to be assessed through evidence-based medicine in order to provide solid proof for their usefulness. Thus, the concept of contact or call centers has emerged as a new and viable reality in the field of IT for health and telemedicine. In this paper we describe a generic contact center that was designed in the context of an EU funded IST for health project with acronym Citizen Health System (CHS). Since the generic contact center is composed by a number of modules, we shall concentrate in the modules dealing with the communication between the patient and the contact center using mobile telecommunications solutions, which can act as link between the internet and the classical computer telephony communication means. We further elaborate on the development tools of such solutions, the interface problems we face, and on the means to convey information from and to the patient in an efficient and medically acceptable way. This application proves the usefulness of wireless technology in providing health care services all around the clock and everywhere the citizen is located, it proves the necessity for restructuring the medical knowledge for education delivery to the patient, and it shows the virtue of interactivity by means of using the limited, yet useful browsing capabilities of the wireless application protocol (WAP) technology.

Communication infrastructure in a contact center for home care monitoring of chronic disease patients.

The Citizen Health System (CHS) is a European Commission (EC) funded project in the field of IST for Health. Its main goal is to develop a generic contact center which in its pilot stage can be used in the monitoring, treatment and management of chronically ill patients at home in Greece, Spain and Germany. Such contact centers, which can use any type of communication technology, and can provide timely and preventive prompting to the patients are envisaged in the future to evolve into well-being contact centers providing services to all citizens. In this paper, we present the structure of such a generic contact center and in particular the telecommunication infrastructure, the communication protocols and procedures, and finally the educational modules that are integrated into this contact center. We discuss the procedures followed for two target groups of patients where two randomized control clinical trials are under way, namely diabetic patients with obesity problems, and congestive heart failure patients. We present examples of the communication means between the contact center medical personnel and these patients, and elaborate on the educational issues involved.

Haemodynamic factors and the important role of local low static pressure in coronary wall thickening.

UNLABELLED: BACKGROUND/STUDY OBJECTIVES: The purpose of our study was to investigate the possible correlation between blood flow physical parameters and the wall thickening in typical human coronary arteries. METHODS: Digitized images of seven transparent arterial segments prepared post-mortem were adopted from a previous study in order to extract the geometry for numerical analysis. Using the exterior outline, reconstructed forms of the vessel geometries were used for subsequent computational fluid dynamic analysis. Data was input to a pre-processing code for unstructured mesh generation. The flow was assumed to be two-dimensional, steady, laminar with parabolic inlet velocity profile. The vessel walls were assumed to be smooth, inelastic and impermeable. Non-Newtonian power law was applied to model blood rheology. The arterial wall thickening was measured and correlated to the wall shear stress, static pressure, molecular viscosity, and near wall blood flow velocity. RESULTS: Wall shear stress, static pressure and near wall velocity magnitude exhibit negative correlation to wall thickening, while molecular viscosity exhibits positive correlation to wall thickening. CONCLUSION: There is a strong correlation between the development of vessel wall thickening and the blood flow physical parameters. Amongst these parameters the role of local low wall static pressure is predominant.

Doppler echocardiographic evaluation of right ventricular diastolic function in hypertrophic cardiomyopathy.

AIMS: Left ventricular diastolic function in patients with hypertrophic cardiomyopathy has been adequately studied. In contrast there are few studies concerning right ventricular diastolic function in hypertrophic cardiomyopathy. We studied right ventricular diastolic function in patients with hypertrophic cardiomyopathy using Doppler echocardiography. METHODS AND RESULTS: We studied 20 patients with hypertrophic cardiomyopathy (mean age 43.6+/-13.8 years) and 20 healthy volunteers (control group, mean age 43+/-13.8 years). We calculated left ventricular and right ventricular diastolic indices using pulsed Doppler echocardiography. Hypertrophic cardiomyopathy patients compared with controls had significantly lower right ventricular-E/A ratio (1.01+/-0.40 vs 1.30+/-0.28, P<0.04), significantly prolonged right ventricular isovolumic relaxation time (170+/-72 vs 32+/-23 ms, P<0.001), and also significantly prolonged right ventricular deceleration time (160+/-58 vs 118+/-35 ms, P<0.01). There was also strong significant correlation between right ventricular deceleration time and left ventricular deceleration time (r=0.78), right ventricular-E/A ratio and left atrial filling fraction (r=-0.55) and between right atrial filling fraction and left atrial filling fraction (r=0.75). CONCLUSIONS: Right ventricular diastolic function in patients with hypertrophic cardiomyopathy is impaired, reflecting abnormal relaxation. Right ventricular diastolic indices correlate well with those of left ventricle.

The ArtAssist Device in chronic lower limb ischemia. A pilot study.

BACKGROUND: Patients with chronic critical limb ischemia following a failed bypass graft or with non-reconstructable distal disease diagnosed angiographically, have a very poor prognosis. This is a prospective pilot study to assess the influence of the ArtAssist Device on pedal blood flow and amputation rate. METHODS: Thirty-three legs in 25 patients were evaluated. Ten legs presented with rest pain, and 23 legs with tissue loss. Nine legs had previously undergone bypass surgery. RESULTS: At a mean follow-up of 3 months, 14 (42%) legs were amputated, and 19 (58%) were saved. Eleven of the amputated legs were in patients with chronic renal failure, a known risk factor. The amputation rate, excluding this group, was 13.6% (3/22). Toe pressures measured initially and after 3 months on the pump showed a significant improvement (p=0.03). Forty percent of patients presenting with rest pain improved, while 26% of foot ulcers healed on the pump. Mortality rate was 12%. CONCLUSIONS: The results from this prospective study are encouraging but need to be validated in a larger prospective randomized study.

Dobutamine stress echocardiography for the detection of myocardial viability in patients with left ventricular dysfunction taking beta blockers: accuracy and optimal dose.

OBJECTIVE: To assess the accuracy of dobutamine stress echocardiography (DSE) and the optimal dose of dobutamine to detect myocardial viability in patients with ischaemic left ventricular (LV) dysfunction who are taking beta blockers, using the recovery of function six months artery revascularisation as the benchmark. PATIENTS: 17 patients with ischaemic LV dysfunction (ejection fraction < 40%) and chronic treatment with beta blockers scheduled to undergo surgical revascularisation. SETTING: Regional cardiothoracic centre. METHODS: All patients underwent DSE one week before and resting echocardiography six months after revascularisation. A wall motion score was assigned to each segment for each dobutamine infusion stage, using the standard 16 segment model of the left ventricle. The accuracy of DSE to predict recovery of resting segmental function was calculated for low dose (5 and 10 microg/kg/min) and for a full protocol of dobutamine infusion (5 to 40 microg/kg/min). RESULTS: Of the 272 segments studied, 158 (58%) were dysfunctional at rest, of which 79 (50%) improved at DSE and 74 (47%) recovered resting function after revascularisation. Analysis of results with a low dose showed a significantly lower sensitivity and negative predictive value than with a full protocol (47% v 81%, p < 0.001 and 65% v 82%, p < 0.05, respectively). The accuracy in the full protocol analysis was comparable with that reported in patients no longer taking beta blockers but was significantly lower than that in the low dose analysis (78% v 66%, p < 0.001). CONCLUSIONS: Findings suggest that beta blocker withdrawal is not necessary before DSE when viability is the clinical information in question. However, a completed protocol with continuous image recording is required to detect the full extent of viability.