β-Blockers Improve In-hospital and Long-term Survival in Patients with Severe Left Ventricular Dysfunction Undergoing Major Vascular Surgery

OBJECTIVES

To study whether beta-blockers reduce in-hospital and long-term mortality in patients with severe left ventricular dysfunction (LVD) undergoing major vascular surgery.

DESIGN

Observational cohort study.

MATERIALS

Five hundred and eleven patients with severe LVD (ejection fraction<30%) undergoing major non-cardiac vascular surgery.

METHODS

In all patients, cardiac risk factors, medication (including beta-blockers), and dobutamine stress echocardiography (DSE) results were noted prior to surgery. DSE was evaluated for rest and stress-induced new wall motion abnormalities. Endpoint was in-hospital and long-term mortality. Propensity scores for beta-blockers were calculated and regression models were used to analyse the relation between beta-blockers and mortality.

RESULTS

Mean age was 64+/-11 years and 383 patients (75%) were male. 139 patients (27%) used beta-blockers. Stress-induced ischemia occurred in 82 patients (16%). Median follow-up was 7 years (interquartile range: 3-10). In-hospital and long-term mortality was observed in 64 (13%) and 171 (33%) patients, respectively. After adjusting for clinical variables, DSE results and propensity scores, beta-blockers were significantly associated with reduced in-hospital and long-term mortality (OR: 0.18, 95% CI: 0.04-0.74 and HR: 0.38, 95% CI: 0.22-0.65, respectively).

CONCLUSION

In patients with severe LVD undergoing major vascular surgery, the use of beta-blockers is associated with a reduced incidence of in-hospital and long-term postoperative mortality.

Statins are associated with a reduced infrarenal abdominal aortic aneurysm growth

OBJECTIVE

To evaluate the effect of statins on aneurysm growth in a group of consecutive patients under surveillance for infrarenal aortic aneurysms (AAA).

MATERIALS AND METHODS

All patients (59 statin users, 91 non-users) under surveillance between January 2002 and August 2005 with a follow-up for aneurysm growth of at least 12 months and a minimum of three diameter evaluations were retrospectively included in the analysis. Multiple regression analysis, weighted with the number of observations, was performed to test the influence of statins on AAA growth rate.

RESULTS

During a median period of 3.1 (1.1-13.1) years the overall mean aneurysm growth rate was 2.95+/-2.8 mm/year. Statin users had a 1.16 mm/year lower AAA growth rate compared to non-users (95% CI 0.33-1.99 mm/year). Increased age was associated with a slower growth (-0.09 mm/year per year, p = 0.003). Female gender (+1.82 mm/year, p = 0.008) and aneurysm diameter (+0.06 mm/year per mm, p = 0.049) were associated with increased AAA growth. The use of non-steroidal anti-inflammatory drugs, chronic lung disease, or other cardiovascular risk factors were not independently associated with AAA growth.

CONCLUSIONS

Statins appear to be associated with attenuation of AAA growth, irrespective of other known factors influencing aneurysm growth.

Contrast echocardiography as a useful additional diagnostic tool in evaluating a primary cardiac tumor

The current report describes a case of a primary cardiac lymphoma. For early and appropriate treatment of a cardiac mass it is not only important to determine its localization and extension but also to differentiate between malignant and benign lesions. This report demonstrates that not only transthoracic echocardiography but also the other different forms of echocardiography such as transesophageal echocardiography, as well as contrast and intracardiac echocardiography, are useful tools in the diagnostic workup of cardiac masses.

Ischemic heart disease in renal transplant candidates: towards non-invasive approaches for preoperative risk stratification

This editorial refers to the paper of R. Sharma et al. entitled "Dobutamine stress echocardiography and cardiac troponin T for the detection of significant coronary artery disease and predicting outcome in renal transplant candidates". The editorial discusses different strategies for cardiac risk assessment in patients with end-stage renal disease undergoing renal transplantation.

Hypotension during hemodialysis results from an impairment of arteriolar tone and left ventricular function

AIMS

Hypotensive episodes are a major complication of hemodialysis. Hypotension during dialysis could be directly related to a reduction in blood volume or to a decrease in cardiovascular activation as a response to decreased cardiac filling. A decreased cardiovascular activation could be due to patient-related or to dialysis-related factors. In order to study the isolated effect of a reduction in filling pressure, lower body negative pressure (LBNP) causes activation of the cardiovascular reactivity with a decrease in cardiac filling, but without the influence of the dialysis procedure that could affect cardiovascular reactivity.

METHODS

We studied the relationship between relative blood volume (RBV), central venous pressure (CVP), systolic arterial pressure, heart rate, stroke volume index (SI), and total peripheral resistance index (TPRI) during a combined dialysis/ultrafiltration and during LBNP to -40 mmHg in 21 hemodialysis patients with a high incidence of hypotension. Systolic arterial pressure, heart rate, SI and TPRI were measured by Finapres. CVP was measured after cannulation of the jugular vein. During dialysis RBV was measured by a blood volume monitor (BVM). In order to study the conditions in which hypotension occurred after dialysis, we divided the patients into 2 groups: hypotensive (H) and non-hypotensive (NH) during dialysis.

RESULTS

Baseline levels did not show any significant differences. During dialysis systolic arterial pressure declined gradually in the H group from 30 minutes before the onset of hypotension. There was a similar decrease of RBV and increase of heart rate in both groups with a large interindividual variation. At hypotension, H patients showed a significantly smaller increase in TPRI as compared to NH patients. The reduction in SI tended to be greater at hypotension, while CVP decreased to a similar extent in both groups. Moreover, during LBNP, a similar reduction in CVP resulted in a much smaller decrease in SI. Systolic arterial pressure was only slightly lowered due to a much greater increase in TPRI.

CONCLUSION

We conclude that dialysis-related hypotension in our patient group did not result from an inability to maintain blood volume or from decreased cardiac filling. Hypotension appeared to result from the inability to adequately increase arteriolar tone and a reduction in left ventricular function. Both vascular tone and left ventricular function appeared to be impaired by the dialysis procedure.

Persistent diastolic dysfunction despite successful long-term octreotide treatment in acromegaly

INTRODUCTION

This study was designed to evaluate potential reversibility of left-ventricular (LV) dysfunction in patients with acromegaly following long-term control of disease. It is unknown whether the cardiac changes induced by acromegaly can be reversed completely by long-term strict control of growth hormone excess by octreotide.

PATIENTS AND METHODS

We compared LV systolic and diastolic function in inactive patients with acromegaly (n = 22), who were divided into patients with long-term control by octreotide (n = 14) and patients with long-term cure by surgery/radiotherapy (n = 8). We also assessed these parameters in patients with active acromegaly (n = 17).

RESULTS

In patients with active acromegaly, systolic function at rest was decreased by 18% (P < 0.01), LV mass index increased by 40% (P < 0.04) and isovolumetric relaxation time increased by 19% (P < 0.01), compared with patients with inactive acromegaly. These parameters were not different between well-controlled and cured patients. Using tissue Doppler imaging, the ratio between early and late diastolic velocity (E'/A' ratio) was decreased in active, compared with inactive acromegaly (0.75+/-0.07 versus 1.24+/-0.15; P < 0.01). This E'/A' ratio was considerably higher in cured, compared with octreotide-treated, patients (1.75+/-0.41 versus 1.05+/-0.1; P < 0.01).

CONCLUSION

Diastolic function is persistently and significantly more impaired in acromegalic patients with long-term control by octreotide than in surgically cured patients, which points to biological effects of subtle abnormalities in growth hormone secretion. Criteria for strict biochemical control of acromegaly should thus be reconsidered.

Underestimation of severity of mitral regurgitation with varying hemodynamics

Transesophageal echocardiography (TEE) is a valuable technique to assess mitral valve anatomy and the mechanism of mitral regurgitation (MR). We present the case of a 35-year-old woman with severe MR due to restrictive motion of the posterior mitral leaflet, who was referred for mitral annuloplasty. Under physiologic circumstances, a severe (grade 3+) MR was present, whereas in the operating room during general anesthesia, the MR had disappeared almost completely. The downgrading of MR due to general anesthesia and the associated mechanisms of this phenomenon are discussed in this case.

Long term outcome in patients with silent versus symptomatic ischaemia during dobutamine stress echocardiography

OBJECTIVES

To compare the long term prognosis of patients having silent versus symptomatic ischaemia during dobutamine stress echocardiography (DSE).

DESIGN

Observational study.

SETTING

Tertiary referral centre.

PATIENTS

931 patients who experienced stress induced myocardial ischaemia during DSE.

RESULTS

Silent ischaemia was present in 643 of 931 patients (69%). The number of dysfunctional segments at rest (mean (SD) 9.6 (5.1) v 8.8 (5.0), p = 0.1) and of ischaemic segments (3.5 (2.2) v 3.8 (2.1), p = 0.2) was comparable in both groups. During a mean (SD) follow up of 5.5 (3.3) years, there were 169 (18%) cardiac deaths and 86 (9%) non-fatal infarctions. Multivariable Cox regression analysis showed age (hazard ratio (HR) 1.1, 95% confidence interval (CI) 1.02 to 1.05), previous myocardial infarction (HR 1.4, 95% CI 1.1 to 2.0), and number of ischaemic segments during the test (HR 2.0, 95% CI 1.0 to 3.7) as independent predictors of cardiac death and myocardial infarction. For every additional ischaemic segment there was a twofold increment in risk of late cardiac events. The annual cardiac death or myocardial infarction rate was 3.0% in patients with symptomatic ischaemia and 4.6% in patients with silent ischaemia (p < 0.01). Silent induced ischaemia was an independent predictor of cardiac death and myocardial infarction (HR 1.7, 95% CI 1.1 to 2.0). During follow up symptomatic patients were treated more often with cardioprotective therapy (p < 0.01) and coronary revascularisation (145 of 288 (50%) v 174 of 643 (27%), p < 0.001).

CONCLUSIONS

Patients with silent ischaemia had a similar extent of myocardial ischaemia during DSE compared to patients with symptomatic ischaemia but received less cardioprotective treatment and coronary revascularisation and experienced a higher cardiac event rate.

Long term prognostic value of myocardial viability and ischaemia during dobutamine stress echocardiography in patients with ischaemic cardiomyopathy undergoing coronary revascularisation

OBJECTIVE

To evaluate the relative merits of viability and ischaemia for prognosis after revascularisation.

METHODS

Low-high dose dobutamine stress echocardiography (DSE) was performed before revascularisation in 128 consecutive patients with ischaemic cardiomyopathy (mean (SD) left ventricular ejection fraction (LVEF) 31 (8)%). Viability (defined as contractile reserve (CR)) and ischaemia were assessed during low and high dose dobutamine infusion, respectively. Cardiac death was evaluated during a five year follow up. Clinical, angiographic, and echocardiographic data were analysed to identify predictors of events.

RESULTS

Univariable predictors of cardiac death were the presence of multivessel disease (hazard ratio (HR) 0.21, p < 0.001), baseline LVEF (HR 0.90, p < 0.0001), wall motion score index (WMSI) at rest (HR 4.02, p = 0.0006), low dose DSE (HR 7.01, p < 0.0001), peak dose DSE (HR 4.62, p < 0.0001), the extent of scar (HR 1.39, p < 0.0001), and the presence of CR in > or = 25% of dysfunctional segments (HR 0.34, p = 0.02). The best multivariable model to predict cardiac death included the presence of multivessel disease, WMSI at low dose DSE, and the presence of CR in > or = 25% of the severely dysfunctional segments (HR 9.62, p < 0.0001). Inclusion of ischaemia in the model did not provide additional predictive value.

CONCLUSION

The findings of the present study illustrate that in patients with ischaemic cardiomyopathy, the extent of viability (CR) is a strong predictor of long term prognosis after revascularisation. Ischaemia did not add significantly in predicting outcome.

Intracardiac pseudotumor caused by mitral annular calcification

The current report describes a rare case of a pseudotumor in the left ventricle. Transthoracic and transesophageal echocardiography demonstrated a round, echodense, mobile mass attached to the posterior mitral leaflet and annulus. At surgical exploration caseous annular calcification of the posterior mitral leaflet was diagnosed. After resection of the mass, successful mitral valvular plasty was performed. Review of the literature indicated that mitral annular calcification is associated with an increased risk of stroke. Optimal treatment may be surgery, especially when valve plasty can be performed, although randomized trials are currently lacking.

Improvement of stress LVEF rather than rest LVEF after coronary revascularisation in patients with ischaemic cardiomyopathy and viable myocardium

OBJECTIVE

To evaluate prospectively the response of left ventricular ejection fraction (LVEF) to high dose dobutamine infusion in patients showing substantial viability, with and without improved resting LVEF after revascularisation.

METHODS

Before and 9-12 months after revascularisation, 50 patients with ischaemic cardiomyopathy (LVEF 32 (8)%) and substantial myocardial viability (> or = 4 viable segments) underwent radionuclide ventriculography and dobutamine stress echocardiography. Patients were divided into group 1, patients with, and group 2, patients without significant improvement in resting LVEF (> or = 5% by radionuclide ventriculography) after revascularisation. The response of LVEF during dobutamine stress echocardiography was compared in these two groups.

RESULTS

Groups 1 and 2 were comparable in baseline characteristics, resting LVEF, and number of viable segments (mean (SD) 7 (4) v 6 (2), not significant). After revascularisation, the LVEF response during dobutamine stress echocardiography improved significantly in both groups (group 1, 34 (10)% to 56 (8)%; group 2, 32 (10)% to 46 (11)%; both p < 0.001). Interestingly, although resting LVEF did not improve in group 2, peak stress LVEF after revascularisation did (p < 0.001). Group 1 patients had, however, a greater increase in peak stress LVEF (group 1, 22 (10)%; group 2, 13 (9)%; p < 0.01). New York Heart Association and Canadian Cardiovascular Society classes decreased in both groups.

CONCLUSIONS

Although patients with viable myocardium did not always have improved rest LVEF after revascularisation, peak stress LVEF improved. Assessment of improvement of resting function may not be the ideal end point to evaluate successful revascularisation.

Assessment of myocardial viability in chronic ischemic heart disease: current status

Assessment of myocardial viability is clinically important in the work-up of patients with ischemic cardiomyopathy. Numerous studies in the past 2 decades demonstrated that revascularization improves left ventricular ejection fraction (LVEF), heart failure symptoms and prognosis in patients with viable myocardium. Conversely patients without viable tissue do not benefit from revascularization. Also, a substantial amount of viable myocardium (at least 25% of the left ventricle) is needed to result in improvement of LVEF. Hence, both identification and quantification of the extent of viable myocardium are required for a careful selection of candidates for revascularization. Indeed, the presence of a substantial amount of viable myocardium decreases the risk of surgery in patients with reduced LVEF. Several diagnostic techniques are available to identify myocardial viability. Positron emission tomography (PET), myocardial perfusion imaging, and stress echocardiography are considered the traditional techniques to evaluate myocardial viability. Recently, newer techniques including cardiac magnetic resonance (CMR), myocardial contrast echocardiography (MCE) and electromechanical mapping have been introduced. In this manuscript the status of the currently available techniques to assess viability was reviewed. Also the relative merits of each technique for prediction of functional recovery and prognosis was addressed. The available retrospective data support the clinical use of viability assessment. Patients with ischemic cardiomyopathy should undergo viability testing to determine therapeutic strategy. In the presence of substantial amount of viable myocardium, patients should undergo revascularization since benefits in terms of left ventricular function, remodeling, symptoms and prognosis may be anticipated. However, prospective randomized trial are needed to confirm these data.

Evaluation of a hand carried cardiac ultrasound device in an outpatient cardiology clinic

OBJECTIVE

To determine the diagnostic potential of a hand carried cardiac ultrasound (HCU) device (OptiGo, Philips Medical Systems) in a cardiology outpatient clinic and to compare the HCU diagnosis with the clinical diagnosis and diagnosis with a full featured standard echocardiography (SE) system.

METHODS

300 consecutive patients took part in the study. The HCU examination was performed by an experienced echocardiographer before patients visited the cardiologist. The echocardiographer noted whether the HCU device was able to confirm or reject the referral diagnosis, which abnormality was detected, and whether SE investigation was necessary. Physical examination by a cardiologist followed and thereafter, whenever required, a complete study with an SE was carried out. The HCU data were compared with the clinical diagnosis of the cardiologist and the SE diagnosis in a blinded manner.

RESULTS

The cardiologist referred 203 of 300 patients for an SE study and 13 patients for transoesophageal echocardiography. In 84 patients no further examination was considered necessary. HCU echocardiography was able to confirm or reject the suspected clinical diagnosis in 159 of 203 (78%) patients. In 44 of 203 (22%) patients SE Doppler was needed. Agreement between the HCU device and the SE system for the detection of major abnormalities was excellent (98%). The HCU device missed 4% of the major findings. Among the 84 patients not referred for an SE, the HCU device detected unsuspected major abnormalities missed with the physical examination in 14 (17%).

CONCLUSION

Integration of an HCU device with the physical examination augments the yield of information.

A Combination of Statins and Beta-blockers is Independently Associated with a Reduction in the Incidence of Perioperative Mortality and Nonfatal Myocardial infarction in Patients Undergoing Abdominal Aortic Aneurysm Surgery

OBJECTIVE

To investigate the combined beneficial effect of statin and beta-blocker use on perioperative mortality and myocardial infarction (MI) in patients undergoing abdominal aortic aneurysm surgery (AAA).

BACKGROUND

Patients undergoing elective AAA-surgery identified by clinical risk factors and dobutamine stress echocardiography (DSE) as being at high-risk often have considerable cardiac complication rate despite the use of beta-blockers.

METHODS

We studied 570 patients (mean age 69+/-9 years, 486 males) who underwent AAA-surgery between 1991 and 2001 at the Erasmus MC. Patients were evaluated for clinical risk factors (age>70 years, histories of MI, angina, diabetes mellitus, stroke, renal failure, heart failure and pulmonary disease), DSE, statin and beta-blocker use. The main outcome was a composite of perioperative mortality and MI within 30 days of surgery.

RESULTS

Perioperative mortality or MI occurred in 51 (8.9%) patients. The incidence of the composite endpoint was significantly lower in statin users compared to nonusers (3.7% vs. 11.0%; crude odds ratio (OR): 0.31, 95% confidence interval (CI): 0.13-0.74; p=0.01). After correcting for other covariates, the association between statin use and reduced incidence of the composite endpoint remained unchanged (OR: 0.24, 95% CI: 0.10-0.70; p=0.01). Beta-blocker use was also associated with a significant reduction in the composite endpoint (OR: 0.24, 95% CI: 0.11-0.54). Patients using a combination of statins and beta-blockers appeared to be at lower risk for the composite endpoint across multiple cardiac risk strata; particularly patients with 3 or more risk factors experienced significantly lower perioperative events.

CONCLUSIONS

A combination of statin and beta-blocker use in patients with AAA-surgery is associated with a reduced incidence of perioperative mortality and nonfatal MI particularly in patients at the highest risk.

Prognostic value of dobutamine stress echocardiography in patients with previous coronary revascularisation

OBJECTIVE

To assess the prognostic value of dobutamine stress echocardiography (DSE) in patients with previous myocardial revascularisation.

DESIGN

Prospective study.

SETTING

Tertiary referral centre in Rotterdam, the Netherlands.

PATIENTS

332 consecutive patients with previous percutaneous or surgical coronary revascularisation underwent DSE. Follow up was successful for 331 (99.7%) patients. Thirty eight patients who underwent early revascularisation (<or= 3 months) after the test were excluded from analysis.

MAIN OUTCOME MEASURES

Cox proportional hazards regression models were used to identify independent predictors of the composite of cardiac events (cardiac death, non-fatal myocardial infarction, and late revascularisation).

RESULTS

During a mean (SD) of 24 (20) months, 37 (13%) patients died and 89 (30%) had at least one cardiac event (21 (7%) cardiac deaths, 11 (4%) non-fatal myocardial infarctions, and 68 (23%) late revascularisations). In multivariate analysis of clinical data, independent predictors of late cardiac events were hypertension (hazard ratio (HR) 1.7, 95% confidence interval (CI) 1.1 to 2.6) and congestive heart failure (HR 2.1, 95% CI 1.3 to 3.2). Reversible wall motion abnormalities (ischaemia) on DSE were incrementally predictive of cardiac events (HR 2.1, 95% CI 1.3 to 3.2).

CONCLUSIONS

Myocardial ischaemia during DSE is independently predictive of cardiac events among patients with previous myocardial revascularisation, after controlling for clinical data.

Long-term prognostic value of asymptomatic cardiac troponin T elevations in patients after major vascular surgery

BACKGROUND

Cardiac troponin T (cTnT) is a sensitive and specific marker for myocardial injury, but elevations of cTnT without clinical evidence of ischemia and persistent or new electrocardiographic (ECG) abnormalities are common in patients undergoing major vascular surgery. We explored the long-term prognostic value of cTnT levels in these patients.

METHODS

A follow-up study was conducted between 1996-2000 in 393 patients who underwent successful aortic or infrainguinal vascular surgery and routine sampling of cTnT. Patients were followed until May 2003 (median of 4 years [25th-75th percentile, 2.8-5.3 years]). Total creatine kinase (CK), CK-MB, and cTnT were routinely screened in all patients, and included sampling after surgery and the mornings of postoperative days 2, 3 and 7. Electrocardiograms were also routinely evaluated for sign of ischemia. An elevated cTnT was defined as serum concentrations >/=0.1 ng/ml in any of these samples. All-cause mortality was evaluated during long-term follow-up.

RESULTS

Eighty patients (20%) had late death. The incidence of all-cause mortality (41% vs. 17%; p<0.001) was significantly higher in patients with an elevated cTnT level compared to patients with normal cTnT. After adjustment for baseline clinical characteristics, the association between an elevated cTnT level and increased incidence of all-cause mortality (adjusted hazard ratio, 1.9; 95% CI, 1.1-3.1) persisted. Elevated cTnT had significant prognostic value in patients with and without renal dysfunction, abnormal levels of CK-MB, and in patients with transient ECG abnormalities.

CONCLUSIONS

Elevated cTnT levels are associated with an increased incidence of all-cause mortality in patients undergoing major vascular surgery.

There are no acute cardiac effects of a single iv dose of human ghrelin in severe growth hormone deficient patients

It has previously been suggested that ghrelin mediates GH-independent biologic activities on the heart. We investigated the acute effects on cardiac contraction of a single iv administration of human ghrelin (in a dose of 1 microg/kg) in severe untreated GH deficient subjects. Prior to the ghrelin infusion, an echocardiographic examination was performed at rest (baseline), after physiologic saline and during dobutamine stress echocardiography (DSE) to exclude a preexisting (subclinical) myocardial dysfunction. To evaluate the acute cardiac effect of infusion and during DSE the velocity of left ventricular (LV) wall contraction was measured continuously by echocardiography. Despite severe GH deficiency we observed in all subjects a normal cardiac function at rest after physiologic saline and during DSE. No acute changes in cardiac performance or cardiac parameters could be observed after a single iv dose of ghrelin. Also, no important increase in GH secretion was detected after ghrelin administration. Our study suggests that, in contrast to hexarelin, a single iv administration of ghrelin in a physiological dose has no acute effects on cardiac function in severe GH deficiency. This suggests that GH-independent effects of ghrelin play no important role in the acute regulation of cardiac function in man.

Aortic valve regurgitation due to cusp aneurysm: a case report

Two-dimensional echocardiography is a valuable tool in visualizing and monitoring aortic valve and root abnormalities. We present a rare case of a patient with massive aortic regurgitation due to cusp aneurysm, which was accurately diagnosed by echocardiography and treated by valve replacement. A complicated course with recurrent aneurysms of the aortic wall after aortic valve replacement was remarkable in this case. Although different possible etiologies could not be determined, endocarditis and/or aortitis may be the most likely explanation of the complicated and finally fatal course of this patient.

Pulsed wave tissue Doppler imaging for the quantification of contractile reserve in stunned, hibernating, and scarred myocardium

OBJECTIVES

To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium.

DESIGN

Observational study.

SETTING

Tertiary referral centre.

PATIENTS

70 patients with reduced left ventricular function caused by chronic coronary artery disease.

METHODS

Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred.

RESULTS

253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001).

CONCLUSIONS

Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damage.

Relation between left ventricular contractile reserve during low dose dobutamine echocardiography and plasma concentrations of natriuretic peptides

BACKGROUND

In ischaemic cardiomyopathy, raised plasma concentrations of natriuretic peptides are associated with a poor long term prognosis, while the presence of contractile reserve is a favourable sign.

OBJECTIVE

To assess the relation between plasma natriuretic peptides and contractile reserve.

DESIGN

Prospective observational study.

SETTING

Tertiary referral centre.

PATIENTS

66 consecutive patients undergoing low dose dobutamine stress echocardiography to evaluate contractile reserve in regions with contractile dysfunction at rest, divided into two groups: group 1, 31 patients with ischaemic cardiomyopathy (left ventricular ejection fraction < or = 40%) and heart failure symptoms; group 2, 35 patients with normal left ventricular function.

MAIN OUTCOME MEASURES

Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), measured using immunoradiometric assays. Contractile reserve was defined as an improvement in segmental wall motion score during infusion of low dose dobutamine.

RESULTS

Plasma ANP and BNP concentrations were higher in group 1 than in group 2 (mean (SD): ANP, 17.8 (32.8) v 7.2 (9.7), p < 0.005; BNP, 24.4 (69.0) v 5.0 (14.3) pmol/l, respectively; p < 0.001). In group 1, the presence of contractile reserve was inversely related to ANP and BNP levels; however, patients with contractile reserve had lower ANP and BNP concentrations than patients without contractile reserve (ANP, 14.2 (9.1) v 24.2 (44.2), p < 0.05; BNP, 20.2 (25.5) v 37.5 (93.8) pmol/l, respectively; p < 0.05).

CONCLUSIONS

Plasma natriuretic peptide concentrations are raised in patients with left ventricular dysfunction, but in the presence of preserved myocardial contractile reserve, relatively low levels of ANP and BNP are present.

[Prophylactic perioperative beta-blockade reduces cardiac morbidity and mortality following non-cardiac surgery in patients at risk]

Approximately 5% of all patients undergoing non-cardiac surgery suffer some form of perioperative cardiac morbidity, usually preceded by myocardial ischaemia. In the Netherlands, the cardiac mortality following non-cardiac surgery is 0.68%. The patient groups at risk for cardiac complications are: age 65 years and older, patients with coronary artery disease or risk factors for coronary artery disease, and those undergoing major surgery. The period of greatest risk is the early postoperative phase. Prophylactic beta-blockade significantly reduces perioperative cardiac morbidity and mortality: the odds ratio for myocardial ischaemia is 0.34 (95% CI: 0.23-0.52), for non-fatal myocardial infarction 0.15 (95% CI: 0.06-0.40) and for cardiac mortality 0.25 (95% CI: 0.09-0.73). Long-term continuation of the beta-blockade also reduces cardiac morbidity and mortality in the first two years following the operation.