Cardioprotection using strain-guided management of potentially cardiotoxic cancer therapy: 1 year results of the SUCCOUR trial

Background

Conventional criteria for diagnosis of chemotherapy-related cardiac dysfunction (CTRCD) are dependent on the recognition of heart failure (HF) symptoms and/or changes in LVEF. However, the low sensitivity of EF for minor changes in LV function may delay initiation of cardio-protective therapy (CPT). Global longitudinal strain (GLS) is a robust and sensitive marker of LV dysfunction (LVD), but existing observational data are insufficient to justify changing the diagnostic criteria for CTRCD.

Purpose

To identify whether GLS guidance of CPT would improve cardiac function of at risk patients undergoing potentially cardiotoxic chemotherapy, compared with usual care.

Methods

In this international multicenter prospective randomized controlled trial, 331 pts from 23 international sites taking anthracyclines with another risk factor for HF were randomly allocated into 166 undergoing GLS-guided (CPT for >12% relative reduction in GLS using Echopac software) and 165 EF-guided (CPT for >10% absolute reduction of EF). Pts were followed over 1 year for the primary end-point (ΔEF) with 3D echo (3DE); 2D echo (2DE) was used when 3D images were unsuitable for measurement. Development of CTRCD (EF reduction of 10% to <55%) was a secondary endpoint.

Results

Of 331 randomized patients, 24 withdrew before follow-up imaging was performed (2 died, and rest withdrew or were lost to follow-up). Among 307 patients (age 54±12 years, 94% women) with follow-up 1.0±0.2 years, 277 had breast cancer, 30 had lymphoma/leukemia. HF risk factors were prevalent: 89 (29%) had hypertension and 39 (13%) had diabetes mellitus. The most common chemotherapy regimen during this study was the combination of anthracycline and trastuzumab. The baseline 3D LVEF was 61±5%, and GLS was −20.8±3.2%. At 1 year follow-up, 31 (10%) met CTRCD and was reduced in the GLS-guided arm (Table 1), although new LV dysfunction (EF<55%) and change of EF were not different.

Conclusion

In this international multicentre trial, the incidence of CTRCD was reduced by strain-guided cardioprotection. Although the final EF and the number of pts developing EF <55% was not altered by strain-guided therapy, this reduces meaningful reduction of EF to the abnormal range. The results support the use of GLS in surveillance for CTRCD.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): General Electric Medical Systems

Effect of continuous positive airway pressure therapy in patients with paroxysmal atrial fibrillation and obstructive sleep apnea: a randomized controlled trial

Background

There is strong evidence for an association between atrial fibrillation (AF) and sleep apnea (SA).

Purpose

We aimed to examine the effect of treatment with continuous positive airway pressure (CPAP) on the burden of AF.

Methods

After a run-in period for CPAP-tolerance, we randomly assigned 108 eligible patients between 18–75 years, who had paroxysmal AF and moderate-to-severe obstructive SA (apnea-hypopnea index (AHI)≥15), to receive either CPAP treatment (n=54) plus usual care or usual care alone (n=54) for five months. An implanted loop recorder measured time in AF continuously. The primary endpoint was the difference in change of AF burden (% of time in AF) between CPAP treatment and usual care from baseline (one month prior to randomization) to the last three months of the intervention period. Secondary endpoints were changes in quality of life assessed by the Short Form-36 (SF-36), Epworth Sleepiness Scale (ESS), and the Functional Outcomes of Sleep Questionnaire (FOSQ).

Results

Mean (SD) age was 62.4 (7.7) years, BMI 29.4 (4.2) kg/m2, ESS 7.9 (3.2), and 76.1% were men. In the intervention group, the mean duration of adherence to CPAP therapy was 4.3 hours/night. During treatment mean AHI decreased from 27.6 events/hour at baseline to 2.3 events/hour during follow-up. Mean time in AF decreased from 5.0%-4.3% in the control group and from 5.6%-4.1% in the CPAP group, but the difference in change was not significant (p=0.52). Sub-analysis of those using CPAP><4 hours/night also showed no difference, neither did the quality of life questionnaires.

Conclusion

This is the first randomized controlled trial to assess the effect of treatment of SA on the burden of AF, and did not detect a difference between those treated with CPAP compared to usual care alone.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Oslo University Hospital is the main funding Source. ResMed Science Center provided an unrestricted grant.

P1350 New 3D Doppler flow method for quantitation of aortic regurgitation

Funding Acknowledgements

Centre for Innovative Ultrasound Solutions, NTNU

OnBehalf

Centre for Innovative Ultrasound Solutions

Introduction

The echocardiographic assessment of valvular regurgitation severity may be challenging. This is reflected in the current EACVI and ASE recommendations, which are quite extensive and include numerous parameters. To date, there are no widely reliable quantitative methods. Moreover, the inter-observer variability in the overall severity assessment is substantial.

Purpose

Development of a new, automated 3D Doppler method for reliable and accurate quantitation of regurgitant volume.

Methods

A 3D high frame rate plane wave imaging sequence is employed to insonate the vena contracta region of the jet using a modified GEVU Vivid E95 system with a 4V probe. In this way we obtain spectral information from all voxels within the sample volume of approximately 2cm x 2cm x 2cm. Vena contracta is localised from the plane containing the maximum velocities and its cross sectional area determined by a power threshold. Velocity-time-integral is then estimated for all voxels within the designated cross sectional area.

For clinical validation, we include patients with aortic regurgitation ranging from mild to severe with a stable sinus rhythm. 3D flow data is recorded immediately after a comprehensive standard echocardiographic exam. The standard exam undergoes expert evaluation in accordance with EACVI recommendations. 3D flow data are currently processed and analysed offline by an independent investigator, blinded to the results from the standard exam.

Results

The results from the first twelve patients are presented in Figure 1. Compared to expert echocardiographic evaluation, the 3D flow method seems to overestimate the regurgitant volume in some patients with mild aortic regurgitation. This may be caused by limitations in lateral resolution. Due to failure of aligning the vena contracta within the sample volume, there is a significant underestimation of regurgitant volume in one patient (Figure 1: red dot). As 3D flow analysis is currently performed offline, this was not obvious at the time of recording. The 3D flow method clearly discriminates the other two patients with severe aortic regurgitation from the patients with mild or moderate regurgitation.

Conclusion

We find these preliminary results encouraging, motivating further work on method refinement and validation.

Abstract P1350 Figure 1

P691Left ventricular systolic function in long term survivors of allogeneic hematopoietic stem cell transplantation

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is increasingly utilized in young patients. Allo-HSCT usually requires myeloablative therapy that is potentially cardiotoxic. In addition, allo-HSCT survivors have a high prevalence of cardiovascular risk factors.

Purpose

We aim to describe left ventricular systolic function in long term survivors after allo-HSCT.

Methods

This study included 104 patients, aged (mean±SD) 18±10 years at allo-HSCT, and follow-up time was 17±6 years. 74% were sufferers of malignant disease. Pre-transplantation therapies consisted of anthracyclines (AnT) in 44% and mediastinal radiotherapy in 2%. Conditioning regimes consisted of cyclophosphamide with bulsulfsan in 77%. 22% received anti-lymphocyte globulin and 6% received total body irradiation. Left ventricular (LV) function was evaluated by 2D and 3D echocardiography. Healthy controls matched for age, sex and BMI were used in group comparisons. Group comparisons were performed by t-tests and chi-square. A linear regression was used to identify contributing factors to reduced systolic LV function in allo-HSCT survivors.

Results

Most parameters of LV systolic function including 2D and 3D LV ejection fraction (LVEF), global longitudinal strain (GLS), mitral annulus excursion (MAPSE) and s' were all significantly impaired after allo-HSCT as compared to the control group. Significant (p<0.05) contributors to LVEF in the multivariate regression analysis were age, AnT dosage, graft versus host disease (GVHD, occurring in 67%) and hypertension (HT, occurring in 31%).

Allo-HSCT Control p value n 104 55 – Gender (female) 56 (54) 29 (53) 0.89 Age (yr) 35±12 36±11 0.44 BMI (kg/m2) 25±5 24±3 0.57 Fractional Shortening (%) 31±6 32±4 0.26 2D LVEF (%) 55±6 59±3 <0.005 3D LVEF (%) 54±5 58±3 <0.005 MAPSE (mm) 13±2 15±2 <0.005 Mean s' (mm) 81±17 89±17 <0.005 2D GLS (%) −17±2 −20±2 <0.005 Values: mean ± SD or n (%), t-test or chi-square.

Conclusion

LV systolic function is reduced in long term survivors of allo-HSCT. Pre-transplantation AnT, HT and GVHD are significantly associated with increased risk of cardiotoxicity.

Acknowledgement/Funding

Norwegian Cancer Foundation and Norwegian ExtraFoundation for Health and Rehabilitation

Circulating annexin A5 predicts mortality in patients with heart failure

BACKGROUND

Natriuretic peptides are currently used to predict mortality in patients with heart failure (HF). However, novel independent biomarkers are needed to improve risk stratification in these patients. We hypothesized that annexin A5 (anxA5) would be highly expressed by organs which are generally affected by HF and that circulating anxA5 levels would predict mortality in HF patients.

METHODS

We prospectively determined the diagnostic value of anxA5, N-terminal pro-B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP) and estimated glomerular filtration rate (eGFR) to predict mortality in 180 HF patients during a median follow-up of 3.6 years. Studies were conducted with anxA5(-/-) mice to investigate the underlying mechanisms.

RESULTS

AnxA5 levels were significantly elevated in HF patients compared to healthy control subjects. Cox regression analysis demonstrated that anxA5, NT-proBNP and eGFR all predict mortality independently. AnxA5 significantly improved the diagnostic efficiency of NT-proBNP alone (improvement of c-statistic from 0.662 to 0.705, P < 0.001) and also combined with eGFR and CRP (improvement of c-statistic from 0.675 to 0.738, P < 0.001) to predict mortality in the Cox regression model. Receiver operating characteristic curve analysis showed that anxA5 predicted 3-year survival (area under curve 0.708) with an optimal cut-off value of 2.24 ng mL(-1) . Using anxA5(-/-) mice, we demonstrated that anxA5 is highly expressed in organs that are often affected by HF including lung, kidney, liver and spleen. Lysis of these organs in vitro resulted in a marked and significant increase in anxA5 concentrations.

CONCLUSION

AnxA5 improves the diagnostic efficiency of conventional biomarkers to predict mortality in HF patients. Whereas natriuretic peptides originate from the myocardium, high circulating anxA5 levels in patients with HF are likely to reflect peripheral organ damage secondary to HF.

Microbiota-dependent metabolite trimethylamine-N-oxide is associated with disease severity and survival of patients with chronic heart failure

OBJECTIVES

Recent metabolomic, experimental and clinical studies have demonstrated that trimethylamine-N-oxide (TMAO), a microbiota-dependent metabolite from dietary phosphatidylcholine and carnitine, is a strong predictor of coronary artery disease (CAD). This finding suggests a link between the gut microbiota and atherosclerosis. The potential impact of TMAO in chronic heart failure (HF) is unknown. We hypothesized that TMAO levels would provide prognostic information about adverse outcomes in chronic HF.

DESIGN

Prospective, observational study including 155 consecutive patients with chronic HF. In addition, 100 patients with stable CAD without HF and 33 matched healthy individuals were included as controls. Plasma levels of TMAO and its precursors choline and betaine were measured, and associations with symptoms, aetiology and transplant-free survival in the patients with HF were explored.

RESULTS

Plasma levels of TMAO (P = 0.01), choline (P < 0.001) and betaine (P < 0.001) were elevated in patients with chronic HF compared to control subjects, with the highest levels in patients with New York Heart Association (NYHA) classes III and IV. Furthermore, TMAO levels were highest in individuals with ischaemic HF, followed by those with stable CAD and nonischaemic HF. TMAO, but not choline or betaine, was associated with reduced transplant-free survival: approximately 50% of patients in the upper tertile of TMAO levels died or received a heart transplant during 5.2 years of follow-up (unadjusted Cox-regression: hazard ratio 2.24, 95% confidence interval 1.28-3.92, P = 0.005).

CONCLUSIONS

TMAO levels were elevated in patients with HF and associated with NYHA class, ischaemic aetiology and adverse outcomes. Future studies should focus on gut microbiota, dietary composition and intestinal dysfunction in relation to TMAO levels and clinical outcome in HF.

The cardiokine secreted Frizzled-related protein 3, a modulator of Wnt signalling, in clinical and experimental heart failure

OBJECTIVES

Experimental studies have shown involvement of Wnt signalling in heart failure (HF). We hypothesized that secreted frizzled-related protein 3 (sFRP3), a modulator of Wnt signalling, is related to the progression of HF.

DESIGN

Circulating sFRP3 was measured in 153 HF patients and compared with 25 healthy controls. The association of sFRP3 with mortality was evaluated in 1202 patients (GISSI-HF trial). sFRP3 mRNA expression was assessed in failing human and murine left ventricles (LV), and cellular localization was determined after fractioning of myocardial tissue. In vitro studies were carried out in cardiac fibroblasts subjected to cyclic mechanical stretch.

RESULTS

(i) Heart failure patients had significantly raised serum sFRP3 levels compared with controls, (ii) during a median follow-up of 47 months, 315 patients died in the GISSI-HF substudy. In univariable Cox regression, tertiles of baseline sFRP3 concentration were significantly associated with all-cause and cardiovascular mortality. After adjustment for demographic and clinical variables, but not for CRP and NT-proBNP, the associations with mortality remained significant for the third tertile (all-cause, HR 1.45, P = 0.011; cardiovascular, HR 1.66, P = 0.003), (iii) sFRP3 mRNA expression was increased in failing human LV, with a decline following LV assist device therapy. LV from post-MI mice showed an increased sFRP3 mRNA level, particularly in cardiac fibroblasts, and (iv) mechanical stretch enhanced sFRP3 expression and release in myocardial fibroblasts.

CONCLUSION

There is an association between increased sFRP3 expression and adverse outcome in HF, suggesting that the failing myocardium itself contributes to an increase in circulating sFRP3.

Altered maternal left ventricular contractility and function during normal pregnancy

OBJECTIVES

To evaluate maternal left ventricular (LV) systolic and diastolic function during normal pregnancy by non-invasive measures of LV contractility incorporating loading conditions.

METHODS

Sixty-five women were examined using echocardiography, including tissue Doppler and two-dimensional speckle tracking, and subclavian artery pulse trace recordings at gestational weeks 14-16, 22-24 and 36, and at 6 months postpartum.

RESULTS

The mean ± SD age of the women was 32.0 ± 4.6 years. Cardiac output and LV end-diastolic volume were on average 20% and 23% higher, respectively, during pregnancy, compared to that at 6 months postpartum (both, P < 0.01). LV ejection fraction, global peak systolic strain and rate-corrected LV velocity of circumferential fiber shortening (Vcfc) were 11%, 6% and 6% lower, respectively, at 36 weeks' gestation compared to at 6 months postpartum (all, P < 0.01). Afterload, measured as LV end-systolic wall stress (ESWS) increased by 10% between 14-16 and 36 weeks' gestation (P < 0.01). Analysis of the relationship between Vcfc and ESWS revealed that LV contractility was lower during pregnancy than at 6 months postpartum. Changes in diastolic function were demonstrated by 11% lower mitral early diastolic (E) wave velocity, 8% lower tissue Doppler early diastolic velocity (e') and 13% higher left atrial area (all P < 0.01) during pregnancy. Tissue Doppler E/e' remained unaltered (P = 0.78).

CONCLUSIONS

During normal pregnancy, LV contractility is lower than it is at 6 months postpartum. This is associated with increased LV and left atrial area, whereas filling pressures are unchanged. These findings suggest that pregnancy exerts a larger load on the cardiovascular system than previously assumed.

High-intensity interval training improves peak oxygen uptake and muscular exercise capacity in heart transplant recipients

Heart transplant (HTx) recipients usually have reduced exercise capacity with reported VO(2peak) levels of 50-70% predicted value. Our hypothesis was that high-intensity interval training (HIIT) is an applicable and safe form of exercise in HTx recipients and that it would markedly improve VO(2peak.) Secondarily, we wanted to evaluate central and peripheral mechanisms behind a potential VO(2peak) increase. Forty-eight clinically stable HTx recipients >18 years old and 1-8 years after HTx underwent maximal exercise testing on a treadmill and were randomized to either exercise group (a 1-year HIIT-program) or control group (usual care). The mean ± SD age was 51 ± 16 years, 71% were male and time from HTx was 4.1 ± 2.2 years. The mean VO(2peak) difference between groups at follow-up was 3.6 [2.0, 5.2] mL/kg/min (p < 0.001). The exercise group had 89.0 ± 17.5% of predicted VO(2peak) versus 82.5 ± 20.0 in the control group (p < 0.001). There were no changes in cardiac function measured by echocardiography. We have demonstrated that a long-term, partly supervised and community-based HIIT-program is an applicable, effective and safe way to improve VO(2peak) , muscular exercise capacity and general health in HTx recipients. The results indicate that HIIT should be more frequently used among stable HTx recipients in the future.

Osteoprotegerin levels predict mortality in patients with symptomatic aortic stenosis

OBJECTIVES

To examine the prognostic value of osteoprotegerin (OPG) levels in relation to all-cause mortality in patients with symptomatic severe aortic stenosis (AS).

DESIGN

We measured plasma OPG levels in 136 patients with symptomatic severe AS and investigated associations with transvalvular gradients, valve area, valve calcification (using ultrasonic backscatter analysis as an estimate) and measures of heart failure. Then, we assessed the prognostic value of elevated plasma OPG in determining all-cause mortality (n = 29) in these patients.

RESULTS

Elevated OPG was poorly correlated with the degree of AS but was associated with increased backscatter measurements and impaired cardiac function. Furthermore, OPG was associated with all-cause mortality in patients with symptomatic AS, even after adjustment for conventional risk markers. The strongest association was obtained by using a combination of high levels of both OPG and N-terminal pro-brain natriuretic peptide (NT-proBNP), suggesting that these markers may reflect distinct pathways in the development and progression of AS.

CONCLUSION

The level of circulating OPG is significantly associated with all-cause mortality alone and in combination with NT-proBNP in patients with severe symptomatic AS.

Undercarboxylated matrix Gla protein is associated with indices of heart failure and mortality in symptomatic aortic stenosis

OBJECTIVE

Matrix Gla protein (MGP) is a calcification inhibitor and alterations in circulating MGP have been observed in different populations characterized by vascular calcification. We hypothesized that patients with calcific valvular aortic stenosis (AS) would have dysregulated circulating MGP levels.

DESIGN AND SUBJECTS

We examined plasma levels of nonphosphorylated carboxylated and undercarboxylated MGP (dp-cMGP and dp-ucMGP, respectively) in 147 patients with symptomatic severe AS and in matched healthy controls.

MAIN OUTCOME MEASURES

We further investigated the relationship between MGP levels and aortic pressure gradients and valve area by echocardiography and measures of heart failure. Finally, we assessed the prognostic value of elevated plasma dp-ucMGP level in relation to all-cause mortality in patients with AS.

RESULTS

We found markedly enhanced plasma levels of dp-cMGP and in particular of dp-ucMGP in patients with symptomatic AS. Although only weak correlations were found with the degree of AS, circulating dp-ucMGP was associated with cardiac function and long-term mortality in multivariate analysis.

CONCLUSIONS

A dysregulated MGP system may have a role in the development of left ventricular dysfunction in patients with symptomatic AS.

Myocardial performance after transmyocardial revascularization with CO(2)laser. A dobutamine stress echocardiographic study

AIMS

Transmyocardial laser revascularization is a treatment for patients with severe angina pectoris not eligible for conventional revascularization. The effects on myocardial function and reversible ischaemia have not been clarified.

METHODS AND RESULTS

One hundred patients with refractory angina not eligible for conventional revascularization were randomized 1:1 to receive continued optimal medical treatment or transmyocardial revascularization with CO(2)laser in addition to medical treatment. Dobutamine stress echocardiography examinations were performed at baseline and at 3 and 12 months after randomization. The effects of transmyocardial revascularization on myocardial function and reversible ischaemia were assessed by visual interpretation of cineloops at rest and during stress in a 16-segment model. After transmyocardial revascularization resting left ventricular wall motion abnormalities increased (P<0.01), whereas wall motion during dobutamine stimulation remained unchanged. The number of probably non-viable segments increased (P<0.01) with a corresponding decrease in the number of ischaemic segments. Fewer patients had the dobutamine infusion discontinued because of chest pain after transmyocardial revascularization with laser, but the chest pain threshold did not increase significantly.

CONCLUSION

Following transmyocardial revascularization, resting wall motion abnormalities worsened, wall motion abnormalities during dobutamine stimulation remained unchanged and the number of probably non-viable segments increased.

Metabolic cardiovascular syndrome after renal transplantation

BACKGROUND

Cardiovascular disease (CVD) is the major cause of death in renal transplant recipients. Traditional risk factors like hypertension, dyslipidaemia and diabetes mellitus are common, but cannot completely account for the high prevalence of CVD in this population. The aim of the present study was to assess whether post-transplant glucose intolerance, defined as post-transplant diabetes mellitus, impaired glucose tolerance, or impaired fasting glucose, is associated with metabolic disturbances known to increase risk of cardiovascular disease, similar to what has been observed in the general population.

METHODS

One hundred and seventy-three consecutive patients were prospectively examined 10 weeks after transplantation. An oral glucose tolerance test was completed in 167 patients. Questionnaires, medical records, and the results of various blood tests were used to evaluate a number of known cardiovascular risk factors in all patients.

RESULTS

Glucose intolerance was present in about one-half the recipients and was associated with age, a positive family history of ischaemic heart disease, acute rejection, higher levels of serum triglycerides, apolipoprotein B and 2-h insulin, and lower levels of serum HDL cholesterol. After adjustment for age and sex, lower HDL cholesterol (P=0.005), higher serum triglycerides (P<0.001), apolipoprotein B (P=0.039) and 2-h insulin (P<0.001) were still associated with post-transplant glucose intolerance.

CONCLUSIONS

Ten weeks after renal transplantation glucose intolerance is associated with a clustering of cardiovascular risk factors and metabolic abnormalities, consistent with a post-transplant metabolic cardiovascular syndrome.

Regional myocardial systolic function during acute myocardial ischemia assessed by strain Doppler echocardiography

OBJECTIVES

We sought to evaluate if echocardiographic strain measurements could detect acute myocardial ischemia, and to compare this new method with myocardial velocity measurements and wall motion score index.

BACKGROUND

Tissue Doppler echocardiography (TDE) is a promising method for assessing regional myocardial function. However, myocardial velocities measured by tissue Doppler echocardiography (TDE) vary throughout the left ventricle (LV) because of tethering effects from adjacent tissue. Strain Doppler echocardiography (SDE) is a new tool for measuring regional myocardial deformation excluding the effect of adjacent myocardial tissue.

METHODS

Seventeen patients undergoing angioplasty of the left anterior descending coronary artery (LAD) were studied. Left ventricular longitudinal wall motion was assessed by TDE and SDE from the apical four-chamber view before, during and after angioplasty from multiple myocardial segments simultaneously.

RESULTS

Systolic strain values were uniformly distributed in the different nonischemic LV segments, whereas systolic velocities decreased from basis to apex. During LAD occlusion, strain measurement showed expansion in the apical septal segment in 16 of 17 patients (7.5 +/- 6.5% vs. -17.7 +/- 7.2%, p < 0.001) and reduced compression in the mid-septal segment (p < 0.05) compared with baseline. Segments not supplied by LAD remained unchanged. Tissue Doppler echocardiography showed reduced velocities in all septal segments (p < 0.05) during angioplasty even though LAD does not supply the basal septal segment. Negative systolic velocities were present in 11 of 17 patients. Wall motion score index increased during ischemia (1.3 +/- 0.4, p < 0.05).

CONCLUSIONS

The new SDE approach might be a more accurate marker than TDE for detecting systolic regional myocardial dysfunction induced by LAD occlusion.

Sublingual nitroglycerin delays arterial wave reflections despite increased aortic "stiffness" in patients with hypertension: a Doppler echocardiography study

Venodilatation with consequent reduction in left ventricular filling and end-diastolic wall stress is an important mechanism for the beneficial effects of nitroglycerin in ischemic heart disease and in left ventricular failure. The effects of sublingual nitroglycerin on arterial pulsatile hemodynamics are less well defined. Doppler echocardiography and the calibrated subclavian artery pulse tracing were used to assess hemodynamics in subjects with sustained arterial hypertension (n = 25) before and 5 to 10 minutes after sublingual deposition of 0.5 mg glyceryl trinitrate. Aortic characteristic impedance was calculated by averaging the modulus of the input impedance (ratio of pressure to flow) at high frequencies and by calculating the ratio of pressure and flow increments during upstroke. The pressure wave was split into forward and backward components, and the reflection coefficient (the ratio of backward to forward pressures) was calculated. Parameters of the arterial bed were estimated by using 2- and 3-element Windkessel models. Nitroglycerin delayed the return of arterial wave reflections by 17% (P =.02) and increased aortic characteristic impedance by 20% (P =. 01), but it did not influence total arterial compliance. Mean arterial pressure decreased 7% (P =.0001), but pulse pressure did not change. Stroke volume and the acceleration time of aortic root flow decreased by 13% (P =.0001) and 8% (P =.01), respectively. Cardiac output decreased 7% (P =.01), despite an increase in heart rate of 10% (P =.0001). Peripheral resistance tended to decrease (4%, P =.06). Thus, in subjects with sustained hypertension, sublingual nitroglycerin dilates peripheral, predominantly muscular arteries with a subsequent delayed return of reflected pressure waves. Reflex activation of the sympathetic nervous system with consequent increased acceleration of left ventricular ejection seems to counteract the effect of reduced mean arterial pressure (distending pressure) with respect to the "stiffness" of the aorta.

Acute regional myocardial ischemia identified by 2-dimensional multiregion tissue Doppler imaging technique

BACKGROUND AND OBJECTIVE

Tissue Doppler echocardiography (TDE) is a promising method for the assessment of regional myocardial function, but pulsed TDE does not provide quantitative data from multiple regions simultaneously. This feature is important for the objective assessment of regional differences in myocardial function. In the present study, we investigated a new off-line TDE method that provides quantitative pulsed velocity data from an unlimited number of regions selected within a 2-dimensional (2D) image. The goal of the study was to determine the ability of this new approach to quantify regional myocardial function during acute myocardial ischemia induced by balloon angioplasty.

METHODS

Twenty-two patients undergoing angioplasty of the left anterior descending coronary artery (LAD) were studied. Left ventricular longitudinal wall motion was assessed by 2D TDE from the apical 4-chamber view before, during, and after angioplasty. Images were sampled at a rate of 69 +/- 15 frames/s, and the off-line analysis allowed simultaneous measurement of velocities in multiple myocardial segments.

RESULTS

There were 3 major alterations in the systolic velocity pattern during LAD occlusion. Peak early systolic velocities along the apical septum were significantly reduced during LAD occlusion (2.8 +/- 1.2 cm/s to 0.6 +/- 1.7 cm/s, P <.001). Myocardial velocities in mid systole suggested paradoxical wall motion (1.0 +/- 1.2 cm/s to -0.8 +/- 0.9 cm/s, P <.001). When comparing the ischemic regions of the left ventricle with the nonischemic regions, each patient demonstrated lower myocardial systolic velocities in the ischemic region. Furthermore, during early diastole, the wall motion of the ischemic segments showed a postsystolic contraction pattern with velocities changing from -0.9 +/- 1.0 cm/s to 1.9 +/- 1.3 cm/s (P <.001).

CONCLUSION

This new 2D TDE approach is able to quantify detailed myocardial velocity profiles from multiple regions simultaneously. Single-beat comparisons of ischemic and nonischemic regions might enhance the sensitivity for diagnosing ischemic heart disease. Reversed systolic wall motion during midsystole and marked positive velocity during early diastole might be new and important markers of myocardial wall ischemia.

Cardiac output measurements during cross-clamping of the descending thoracic aorta in pigs. A comparison between transit-time ultrasound, thermodilution and pulsed Doppler ultrasound

BACKGROUND

Cross-clamping of the descending thoracic aorta (XC) induces an increase in cardiac output (CO). The intention of this study was to evaluate the high CO during XC by the use of clinically available methods (thermodilution and pulsed Doppler ultrasound) compared to transit-time ultrasound flowmetry of the ascending aorta as the gold standard.

METHOD

Ten pigs were anaesthetised with ketamine and fentanyl. The descending thoracic aorta was cross-clamped for 30 min, and cardiac output was measured with pulmonary artery thermodilution technique, pulsed Doppler ultrasound on the aortic annulus and transit-time ultrasound flowmetry of the ascending aorta.

RESULTS

At 15 min following XC, CO increased from 1.7 l/min to 4.6 l/min measured with transit-time ultrasound (P<0.05). With thermodilution technique, CO increased from 2.6ll/min to 5.7 l/min (P<0.05), and from 2.4 l/min to 6.0 l/min measured with Doppler ultrasound (P<0.05). There was an increase in mean arterial pressure of 81% and heart rate increased 76% (P<0.05).

CONCLUSION

XC of the descending thoracic aorta induces an increase in CO of 171%. Thermodilution and pulsed Doppler ultrasound are reliable methods for detecting high cardiac output during thoracic aortic surgery.

[Cardiovascular disease after kidney transplantation]

Norwegian renal transplant recipients have a high prevalence of cardiovascular disease. In this group of patients cardiovascular disease causes three out of four deaths. Well-known risk factors such as hypertension, dyslipidemia, impaired glucose tolerance and diabetes mellitus are common in renal transplant recipients, but these factors cannot fully explain the high cardiovascular morbidity and mortality. Atherosclerotic disease and left ventricular hypertrophy are highly prevalent in uremic patients before transplantation. Hyperhomocysteinemia, elevated levels of advanced glycosylated end products, and immunosuppressive medication may also accelerate the atherosclerotic process. Until results from controlled trials on the effect of lipid-lowering therapy in renal transplant recipients are available, treatment decisions must be based on studies in non-transplanted patients. Every patient should be treated individually with the overall risk pattern taken into account.

Reversal of intraventricular flow propagation during isovolumic relaxation: A marker of anterior wall dysfunction

BACKGROUND

Myocardial infarction induces left ventricular (LV) wall motion abnormalities during isovolumic relaxation (IVR) and may potentially alter intraventricular flow during this period. This study evaluated whether 2-dimensional color Doppler measurements of intraventricular flow during IVR were able to identify LV dysfunction caused by coronary artery disease.

METHODS

Patients with single-vessel coronary artery disease and posterior wall infarction (21 patients) or anterior wall infarction (27 patients) were included. Eighteen healthy persons served as a control group. LV function was examined by 2-dimensional echocardiography, 2-dimensional color Doppler, and pulsed Doppler techniques.

RESULTS

All normal persons (23.6 +/- 10.9 cm/s) and patients with posterior infarction (19.6 +/- 9.3 cm/s) had flow propagation towards LV apex during IVR. Patients with anterior wall infarction had reversed flow direction (-12.2 +/- 8.7 cm/s, P <.001). The echocardiographic wall motion score index of the 4 apical segments correlated well with flow velocities (r = -0.78, P <.001).

CONCLUSION

Reversed flow propagation during IVR may become a sensitive clinical marker of regional ischemia.

Cardiovascular morbidity and risk factors in renal transplant patients

BACKGROUND

Cardiovascular disease is now the major cause of death in renal transplant patients. This study aimed to assess the prevalence of cardiovascular disease in stable renal transplant patients as compared with the general background population, and to assess risk factors for cardiovascular disease in this patient group.

METHODS

A cross-sectional multicentre study comprising 406 stable renal transplant patients (age 47+/-16 years, 60% males, 71% taking cyclosporin A) were assessed clinically and biochemically 48 months (median) after transplantation and compared with the general population. Multivariate analysis was used to assess the relation between cardiovascular disease and risk factors.

RESULTS

Hypertension was present in 55% of males and 34% of females (P<0.001), in 51% with cyclosporin A and in 33% without (P<0.001). Ischaemic heart disease (i.e. angina pectoris and/or previous myocardial infarction) was present in 14% (males: 18%, females: 10%, P<0.05) and in 24% of diabetics vs 12% of non-diabetics (P<0.01). Cerebro- and peripheral vascular disease was found in 3% and 4%, respectively. Odds ratio for angina pectoris (patients vs general population) was: in age group 40-49 years (males/females), 12/16; 50-59 years, 6/4; 60-69 years, 3/4. Ischaemic heart disease was, besides age and gender, independently associated with total cholesterol (P<0.01), and peripheral vascular disease to systolic blood pressure (P<0.01).

CONCLUSIONS

Cardiovascular disease is highly prevalent in renal transplant patients, and is independently associated with age, gender, total cholesterol and systolic blood pressure.