Optimal effectiveness of heart failure management - an umbrella review of meta-analyses examining the effectiveness of interventions to reduce (re)hospitalizations in heart failure

Heart failure (HF) is a major health concern, which accounts for 1-2% of all hospital admissions. Nevertheless, there remains a knowledge gap concerning which interventions contribute to effective prevention of HF (re)hospitalization. Therefore, this umbrella review aims to systematically review meta-analyses that examined the effectiveness of interventions in reducing HF-related (re)hospitalization in HFrEF patients. An electronic literature search was performed in PubMed, Web of Science, PsycInfo, Cochrane Reviews, CINAHL, and Medline to identify eligible studies published in the English language in the past 10 years. Primarily, to synthesize the meta-analyzed data, a best-evidence synthesis was used in which meta-analyses were classified based on level of validity. Secondarily, all unique RCTS were extracted from the meta-analyses and examined. A total of 44 meta-analyses were included which encompassed 186 unique RCTs. Strong or moderate evidence suggested that catheter ablation, cardiac resynchronization therapy, cardiac rehabilitation, telemonitoring, and RAAS inhibitors could reduce (re)hospitalization. Additionally, limited evidence suggested that multidisciplinary clinic or self-management promotion programs, beta-blockers, statins, and mitral valve therapy could reduce HF hospitalization. No, or conflicting evidence was found for the effects of cell therapy or anticoagulation. This umbrella review highlights different levels of evidence regarding the effectiveness of several interventions in reducing HF-related (re)hospitalization in HFrEF patients. It could guide future guideline development in optimizing care pathways for heart failure patients.

Electrocardiogram-based mortality prediction in patients with COVID-19 using machine learning

Background and purpose

The electrocardiogram (ECG) is frequently obtained in the work-up of COVID-19 patients. So far, no study has evaluated whether ECG-based machine learning models have added value to predict in-hospital mortality specifically in COVID-19 patients.

Methods

Using data from the CAPACITY-COVID registry, we studied 882 patients admitted with COVID-19 across seven hospitals in the Netherlands. Raw format 12-lead ECGs recorded within 72 h of admission were studied. With data from five hospitals (n = 634), three models were developed: (a) a logistic regression baseline model using age and sex, (b) a least absolute shrinkage and selection operator (LASSO) model using age, sex and human annotated ECG features, and (c) a pre-trained deep neural network (DNN) using age, sex and the raw ECG waveforms. Data from two hospitals (n = 248) was used for external validation.

Results

Performances for models a, b and c were comparable with an area under the receiver operating curve of 0.73 (95% confidence interval [CI] 0.65–0.79), 0.76 (95% CI 0.68–0.82) and 0.77 (95% CI 0.70–0.83) respectively. Predictors of mortality in the LASSO model were age, low QRS voltage, ST depression, premature atrial complexes, sex, increased ventricular rate, and right bundle branch block.

Conclusion

This study shows that the ECG-based prediction models could be helpful for the initial risk stratification of patients diagnosed with COVID-19, and that several ECG abnormalities are associated with in-hospital all-cause mortality of COVID-19 patients. Moreover, this proof-of-principle study shows that the use of pre-trained DNNs for ECG analysis does not underperform compared with time-consuming manual annotation of ECG features.

Supplementary Information

The online version of this article (10.1007/s12471-022-01670-2) contains supplementary material, which is available to authorized users.

Clinical presentation, disease course, and outcome of COVID-19 in hospitalized patients with and without pre-existing cardiac disease: a cohort study across 18 countries

AIMS

Patients with cardiac disease are considered high risk for poor outcomes following hospitalization with COVID-19. The primary aim of this study was to evaluate heterogeneity in associations between various heart disease subtypes and in-hospital mortality.

METHODS AND RESULTS

We used data from the CAPACITY-COVID registry and LEOSS study. Multivariable Poisson regression models were fitted to assess the association between different types of pre-existing heart disease and in-hospital mortality. A total of 16 511 patients with COVID-19 were included (21.1% aged 66-75 years; 40.2% female) and 31.5% had a history of heart disease. Patients with heart disease were older, predominantly male, and often had other comorbid conditions when compared with those without. Mortality was higher in patients with cardiac disease (29.7%; n = 1545 vs. 15.9%; n = 1797). However, following multivariable adjustment, this difference was not significant [adjusted risk ratio (aRR) 1.08, 95% confidence interval (CI) 1.02-1.15; P = 0.12 (corrected for multiple testing)]. Associations with in-hospital mortality by heart disease subtypes differed considerably, with the strongest association for heart failure (aRR 1.19, 95% CI 1.10-1.30; P < 0.018) particularly for severe (New York Heart Association class III/IV) heart failure (aRR 1.41, 95% CI 1.20-1.64; P < 0.018). None of the other heart disease subtypes, including ischaemic heart disease, remained significant after multivariable adjustment. Serious cardiac complications were diagnosed in <1% of patients.

CONCLUSION

Considerable heterogeneity exists in the strength of association between heart disease subtypes and in-hospital mortality. Of all patients with heart disease, those with heart failure are at greatest risk of death when hospitalized with COVID-19. Serious cardiac complications are rare during hospitalization.

How often and to what extent do admitted COVID-19 patients have signs of cardiac injury?

Background

COVID-19 can cause myocardial injury in a significant proportion of patients admitted to the hospital and seems to be associated with worse prognosis. The aim of this review was to study how often and to what extent COVID-19 causes myocardial injury and whether this is an important contributor to outcome with implications for management.

Methods

A literature search was performed in Medline and Embase. Myocardial injury was defined as elevated cardiac troponin (cTn) levels with at least one value > 99th percentile of the upper reference limit. The primary outcome measure was mortality, whereas secondary outcome measures were intensive care unit (ICU) admission and length of hospital stay.

Results

Four studies and one review were included. The presence of myocardial injury varied between 9.6 and 46.3%. Myocardial injury was associated with a higher mortality rate (risk ratio (RR) 5.54, 95% confidence interval (CI) 3.48–8.80) and more ICU admissions (RR 3.78, 95% CI 2.07–6.89). The results regarding length of hospital stay were inconclusive.

Conclusion

Patients with myocardial injury might be classified as high-risk patients, with probably a higher mortality rate and a larger need for ICU admission. cTn levels can be used in risk stratification models and can indicate which patients potentially benefit from early medication administration. We recommend measuring cTn levels in all COVID-19 patients admitted to the hospital or who deteriorate during admission.

Supplementary Information

The online version of this article (10.1007/s12471-021-01571-w) contains supplementary material, which is available to authorized users.

Long-term prognostic value of quantitative myocardial perfusion in patients with chest pain and normal coronary arteries

BACKGROUND

Patients with chest pain and no obstructive coronary artery disease have shown a high incidence of major adverse cardiovascular events (MACE). We evaluated the role of absolute myocardial perfusion quantification in predicting all-cause mortality and MACE during long-term follow-up in this group of patients.

METHODS

We studied 79 patients who underwent Nitrogen-13 ammonia PET for quantification of global myocardial blood flow (MBF) and myocardial flow reserve (MFR) due to suspected impaired myocardial perfusion. Patients with coronary artery disease (i.e., > 30% stenosis in one or more coronary arteries) were excluded. We assessed all-cause mortality and MACE. MACE was defined as the composite incidence of death, myocardial infarction (MI), or hospitalization due to heart failure.

RESULTS

Median follow-up was 8 (IQR: 3-14) years. Univariate Cox regression showed that only MFR (P = 0.01) was a predictor of all-cause mortality. Univariate Cox regression analysis showed that both MFR and Stress MBF were predictors of the composite endpoint of MACE (P < 0.001 and P = 0.01, respectively).

CONCLUSION

Quantitative assessment of myocardial perfusion may predict all-cause mortality and MACE in patients with chest pain and normal coronary arteries in the long-term follow-up.

Quantitative myocardial perfusion evaluation with positron emission tomography and the risk of cardiovascular events in patients with coronary artery disease: a systematic review of prognostic studies

Aims

To evaluate the prognostic value of quantitative myocardial perfusion imaging with positron emission tomography (PET) for adverse cardiovascular outcomes in patients with known or suspected coronary artery disease (CAD).

Methods and results

A search in MEDLINE and Embase was conducted for studies that evaluated (i) myocardial perfusion in absolute terms with PET, (ii) prognostic value for the development of major adverse cardiovascular events (MACE), cardiac death, and/or all-cause mortality, and (iii) patients with known or suspected CAD. Studies were divided according to the radiotracer utilized and their included population (patients with and without previous infarction). Comprehensive description and a selected instance of pooling were performed. Eight studies (n = 6804) were analysed and documented clear variability in population, quantitative PET variables operationalization [stress myocardial blood flow (sMBF) and flow reserve (MFR)], statistical covariate structure, follow-up, and radiotracer utilized. MFR was independently associated with MACE in eight studies [range of adjusted hazard ratios (HRs): 1.19–2.93]. The pooling instance demonstrated that MFR significantly associates with the development of MACEs (HR: 1.92 [1.29, 2.84]; P = 0.001). sMBF was only associated with MACE in two studies that evaluated it, and only one study documented sMBF as a better predictor than MFR.

Conclusion

This systematic review demonstrates the prognostic value of quantitative myocardial perfusion evaluated with PET, in the form of MFR and sMBF, for the development of major adverse cardiovascular outcomes in populations with known or suspected CAD. In the qualitative comparison, MFR seems to outperform sMBF as an independent prognostic factor. Evidence is still lacking for assessing quantitative PET for the occurrence of cardiac death and all-cause mortality. There is clear heterogeneity in predictor operationalization and study performances.

Myocardial bridging of the left anterior descending coronary artery is associated with reduced myocardial perfusion reserve: a 13N-ammonia PET study

Myocardial Bridging (MB) refers to the band of myocardium that abnormally overlies a segment of a coronary artery. This paper quantitatively evaluates the influence of MB of the left anterior descending artery (LAD) on myocardial perfusion of the entire left ventricle. We studied 131 consecutive patients who underwent hybrid rest/stress ¹³N-ammonia positron emission tomography (PET) and coronary computed tomography angiography (CCTA) due to suspected myocardial ischemia. Patients with previous myocardial infarction and/or significant coronary artery disease (≥ 50% stenosis) were excluded. Myocardial perfusion measurements were compared between patients with and without LAD-MB. Additionally, we evaluated the relationship between anatomical characteristics (length and depth) of LAD-MB and myocardial perfusion measurements. 17 (13%) patients presented a single LAD-MB. Global myocardial perfusion reserve (MPR) was lower in patients with LAD-MB than in patients without LAD-MB (1.9 ± 0.5 vs. 2.3 ± 0.6, p < 0.01). Global stress myocardial blood flow (MBF) was similar in patients with and without LAD-MB (2.2 ± 0.4 vs. 2.3 ± 0.7 ml/g/min, p = 0.40). Global rest MBF was higher in patients with LAD-MB than in patients without LAD-MB (1.2 ± 0.3 vs. 1.0 ± 0.2 ml/g/min, p < 0.01). Global rest MBF, stress MBF, and MPR quantifications were similar in patients with superficial and deep LAD-MB (all p = NS). We did not find any correlation between length and global rest MBF, stress MBF nor MPR (r = − 0.14, p = 0.59; r = 0.44, p = 0.07; and r = 0.45, p = 0.07 respectively). Quantitative myocardial perfusion suggests that LAD-MB may be related to impaired perfusion reserve, an indicator of microvascular dysfunction. Anatomical characteristics of LAD-MB were not related to changes in myocardial perfusion.

Stress myocardial blood flow correlates with ventricular function and synchrony better than myocardial perfusion reserve: A Nitrogen-13 ammonia PET study

BACKGROUND

Cardiac PET quantifies stress myocardial blood flow (MBF) and perfusion reserve (MPR), while ECG-gated datasets can measure components of ventricular function simultaneously. Stress MBF seems to outperform MPR in the detection of significant CAD. However, it is uncertain which perfusion measurement is more related to ventricular function. We hypothesized that stress MBF correlates with ventricular function better than MPR in patients studied for suspected myocardial ischemia.

METHODS

We studied 248 patients referred to a rest and adenosine-stress Nitrogen-13 ammonia PET. We performed a multivariate analysis using systolic function (left ventricular ejection fraction, LVEF), diastolic function (mean filling rate in diastole, MFR/3), and synchrony (Entropy) as the outcome variables, and stress MBF, MPR, and relevant covariates as the predictors. Secondarily, we repeated the analysis for the subgroup of patients with and without a previous myocardial infarction (MI).

RESULTS

166 male and 82 female patients (mean age 63 ± 11 and 67 ± 11 year, respectively) were included. 60% of the patients presented hypertension, 57% dyslipidemia, 21% type 2 diabetes mellitus, 45% smoking, and 34.7% a previous MI. Mean stress MBF was 1.99 ± 0.75 mL/g/min, MPR = 2.55 ± 0.89, LVEF = 61.6 ± 15%, MFR/3 = 1.12 ± 0.38 EDV/s, and Entropy = 45.6 ± 11.3%. There was a significant correlation between stress MBF (P < .001) and ventricular function. This was stronger than the one for MPR (P = .063). Sex, age, diabetes, and extent of previous MI were also significant predictors. Results were similar for the analyses of the 2 subgroups.

CONCLUSION

Stress MBF is better correlated with ventricular function than MPR, as evaluated by Nitrogen-13 ammonia PET, independently from other relevant cardiovascular risk factors and clinical covariates. This relationship between coronary vasodilatory capacity and ventricular function is sustained across groups with and without a previous MI.

Type 2 diabetes mellitus correlates with systolic function during myocardial stress perfusion scanning with Nitrogen-13 ammonia PET

BACKGROUND

The influence of type 2 diabetes mellitus (DM2) on systolic function is partially determined by the coronary vasodilator function, nevertheless, an independent effect is suspected. We evaluated the relationship between DM2 and systolic function considering PET quantitative myocardial perfusion.

METHODS

We analyzed 585 patients without a previous myocardial infarction referred to a rest and adenosine stress Nitrogen-13 ammonia PET. A bootstrapped multiple linear regression analysis was performed using DM2, stress myocardial blood flow (sMBF), myocardial perfusion reserve (MPR), and clinical risk factors as predictors and LVEF as the outcome variable; an interaction term was additionally investigated.

RESULTS

Two hundred and ninety male and 295 female patients (mean age 65.3 ± 9.9 and 67.4 ± 10 years, respectively) were included. 57.1% presented hypertension, 16% smoking, 37.6% hypercholesterolemia, 33.8% family history for CAD, and 15.2% DM2. The mean MPR was 2.13 ± 0.48 and 2.21 ± 0.60, mean sMBF was 2.01 ± 0.51 and 2.15 ± 0.54, and mean LVEF was 63% ± 10.4 and 67% ± 10.1 for diabetics and non-diabetics, respectively. A significant relation was detected for sMBF (B = 5.830 95% CI [3.505, 9.549], P = .001) and DM2 (B = -2.599 95% CI [-5.125, -0.119], P = .03) with LVEF. The interaction (DM2 × sMBF) yielded no significance (P = .512).

CONCLUSION

DM2 influences PET-measured systolic function in patients without previous myocardial infarction independently from myocardial perfusion parameters. Our study supports the importance of DM2 as an independent risk factor for deteriorating systolic function.

Relationship between epicardial adipose tissue and subclinical coronary artery disease in patients with extra-cardiac arterial disease

OBJECTIVE

Epicardial adipose tissue (EAT) and mediastinal adipose tissue (MAT) are linked to coronary artery disease (CAD). The association between EAT, MAT, and severity of CAD in known extra-cardiac arterial disease was investigated.

DESIGN AND METHODS

Sixty-five cardiac asymptomatic patients (mean age 65 ± 8 years, 69% male) with peripheral arterial disease, carotid stenosis, or aortic aneurysm underwent coronary computed tomography angiography. Patients were divided into non-significant (<50% stenosis, N = 35), single vessel (N = 15) and multi-vessel CAD (N = 15). EAT and MAT were quantified on computed tomography images using volumetric software.

RESULTS

Subgroups did not significantly differ by age, gender, or cardiovascular risk factors. Median EAT was 99.5, 98.0, and 112.0 cm(3) (P = 0.38) and median MAT was 66.0, 90.0, and 81.0 cm(3) (P = 0.53) for non-significant, single vessel, and multi-vessel CAD, respectively. In age- and gender-adjusted analysis, only EAT was significantly associated with CAD (odds ratio [OR] 1.12 [95% confidence interval, 1.01-1.25] per 10 cm(3) increase in EAT; P = 0.04). This remained in multivariate-adjusted analysis (OR 1.21 [1.04-1.39]; P = 0.01).

CONCLUSIONS

In patients with known extra-cardiac arterial disease, CAD is correlated with EAT, but not with MAT. These results suggest that EAT has a local effect on coronary atherosclerosis, apart from the endocrine effect of visceral fat.

Calcification as a risk factor for rupture of abdominal aortic aneurysm

OBJECTIVES

Abdominal aortic aneurysm (AAA) is a major cause of death in developed countries. The AAA diameter is still the only validated prognostic measure for rupture, and therapeutic interventions are initiated accordingly. This still leads to unnecessary interventions in some cases or unidentified impending ruptures. Vascular calcification has been validated abundantly as a risk factor in the cardiovascular field and may strengthen the rupture risk assessment of the AAA. With this study we aim to assess the correlation between AAA calcification and rupture risk in a retrospective unmatched case-control population.

METHODS

A database of 334 AAA patients was evaluated. Three groups were formed: elective (eAAA; n = 233), ruptured (rAAA; n = 73) and symptomatic non-ruptured (sAAA; n = 28) AAA patients. The Abdominal Aortic Calcification-8 score (AAC-8) was used to measure the severity of vascular calcification.

RESULTS

The AAA diameter (61 ± 12 mm vs. 74 ± 21 mm; p < .001) and AAC-8 score (3.4 ± 2 points vs. 4.9 ± 2.3 points; p < .001) of the eAAA and the combined rAAA and sAAA groups, respectively, were significantly different after univariate analysis. Multivariate analysis showed that larger AAA diameter (odds ratio [OR]: 1.048/mm increase; 95% confidence interval [CI]: 1.042-1.082; p < .001) and a higher AAC-8 score (OR: 1.34/point increase; 95% CI: 1.19-1.53; p < .001) were significantly associated with development into a sAAA or rAAA. Peripheral artery disease was significantly correlated to eventual elective treatment (OR: 0.39; 95% CI: .15-1; p = .049).

CONCLUSION

This study suggests a trend of an increased degree of calcification in symptomatic or even ruptured AAA patients compared with elective AAA patients.

Novel serum biomarkers in carotid artery stenosis: useful to identify the vulnerable plaque?

OBJECTIVES

Serum biomarkers representing inflammatory activity in vulnerable carotid plaques may be used to identify high-risk patients for cerebral ischemic events. We aimed to analyze the relationship between concentrations of four novel biomarkers and neurological symptoms: Neopterin, PTX3, sCD163, and sTREM-1. In addition, we analyzed the relationship between these markers and the presence of coronary (CAD) and peripheral (PAD) artery disease.

DESIGN AND METHODS

Serum biomarker levels were determined in 100 patients undergoing carotid endarterectomy; 33 for stroke, 32 for transient ischemic attack, and 23 for amaurosis fugax. 12 Patients were asymptomatic. Risk factors for atherosclerotic disease and history of CAD and PAD were also assessed.

RESULTS

Symptomatic patients did not show significantly elevated biomarker levels compared to asymptomatic patients and levels did not differ among symptomatic subgroups. Neopterin levels were elevated in patients with concomitant coronary and peripheral artery disease (CAD (32%) 10.2 ± 6.6 vs no CAD (68%) 7.6 ± 2.9 nmol/L, PAD (20%) 12.3 ± 7.4 vs no PAD (80%) 7.5 ± 3.0 nmol/L, p<0.05). sTREM-1 was elevated in patients with CAD (50.8 ± 53.2 vs 28.0 ± 31.6 ng/L, p<0.05). PTX3 and sCD163 were not significantly elevated in CAD nor PAD.

CONCLUSION

Our findings suggest that serum neopterin and sTREM-1 levels may be related to the presence of atherosclerotic disease, but not to carotid plaque vulnerability.

A genome-wide association study identifies a region at chromosome 12 as a potential susceptibility locus for restenosis after percutaneous coronary intervention

Percutaneous coronary intervention (PCI) has become an effective therapy to treat obstructive coronary artery diseases (CAD). However, one of the major drawbacks of PCI is the occurrence of restenosis in 5-25% of all initially treated patients. Restenosis is defined as the re-narrowing of the lumen of the blood vessel, resulting in renewed symptoms and the need for repeated intervention. To identify genetic variants that are associated with restenosis, a genome-wide association study (GWAS) was conducted in 295 patients who developed restenosis (cases) and 571 who did not (controls) from the GENetic Determinants of Restenosis (GENDER) study. Analysis of ~550 000 single nucleotide polymorphisms (SNPs) in GENDER was followed by a replication phase in three independent case-control populations (533 cases and 3067 controls). A potential susceptibility locus for restenosis at chromosome 12, including rs10861032 (P(combined) = 1.11 × 10(-7)) and rs9804922 (P(combined) = 1.45 × 10(-6)), was identified in the GWAS and replication phase. In addition, both SNPs were also associated with coronary events (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023) in a trial based cohort set of elderly patients with (enhanced risk of) CAD (PROSPER) and all-cause mortality in PROSPER (rs10861032, P(additive) = 0.007; rs9804922, P(additive) = 0.013) and GENDER (rs10861032, P(additive) = 0.005; rs9804922, P(additive) = 0.023). Further analysis suggests that this locus could be involved in regulatory functions.

Matrix metalloproteinases 2 and 3 gene polymorphisms and the risk of target vessel revascularization after percutaneous coronary intervention: Is there still room for determining genetic variation of MMPs for assessment of an increased risk of restenosis?

OBJECTIVE

Mixed results have been reported of matrix metalloproteinases (MMP) and their association with restenosis after percutaneous coronary intervention (PCI). The current study examines whether multiple single nucleotide polymorphisms (SNPs), covering the full genomic region of MMP2 and MMP3, were associated with restenosis in the GENDER study population.

METHODS AND RESULTS

The GENetic DEterminants of Restenosis (GENDER) study enrolled 3104 consecutive patients after successful PCI. The primary endpoint was clinical restenosis, defined as target vessel revascularization (TVR), occurring in 9.8% of the patients. From the Hapmap database, 19 polymorphisms of MMP2 and 11 of MMP3 were selected. Furthermore, in a subpopulation, a genome-wide association analysis (GWA) was performed. No significant association was found with any of the investigated SNPs, including the previously reported 5A/6A polymorphism (rs3025058), with regard to TVR using single SNP analysis or haplotype analysis.

CONCLUSION

We found no significant association of MMP2 or MMP3 with TVR with this SNP-broad gene approach. Although we did not test all the known polymorphisms of these genes, using tagging analyses we examined those SNPs covering all known haplotypes of MMP2 and MMP3 to conclude that these genes do not correlate with a genetic risk of coronary restenosis after successful PCI.

Myocardial perfusion reserve compared with peripheral perfusion reserve: a [13N]ammonia PET study

INTRODUCTION

[13N]ammonia PET allows quantification of myocardial perfusion. The similarity between peripheral flow and myocardial perfusion is unclear. We compared perfusion flow in the myocardium with the upper limb during rest and adenosine stress [13N]ammonia PET to establish whether peripheral perfusion reserve (PPR) correlates with MPR.

METHODS

[13N]ammonia myocardial perfusion PET-scans of 58 patients were evaluated (27 men, 31 women, age 64 ± 13 years) and were divided in four subgroups: patients with coronary artery disease (CAD, n = 15), cardiac syndrome X (SX, n = 14), idiopathic dilating cardiomyopathy (DCM, n = 16), and normal controls (NC, n = 13). Peripheral limb perfusion was measured in the muscular tissue of the proximal upper limb and quantified through a 2-tissue-compartment model and the PPR was calculated (stress/rest ratio). MPR was also calculated by a 2-tissue-compartment model. The PPR results were compared with the MPR findings.

RESULTS

Mean myocardial perfusion increased significantly in all groups as evidenced by the MPR (CAD 1.99 ± 0.47; SX 1.39 ± 0.31; DCM 1.72 ± 0.69; NC 2.91 ± 0.78). Mean peripheral perfusion also increased but not significantly and accompanied with great variations within and between groups (mean PPR: CAD 1.30 ± 0.79; SX 1.36 ± 0.71; DCM 1.60 ± 1.22; NC 1.27 ± 0.63). The mean difference between PPR and MPR for all subpopulations varied widely. No significant correlations in flow reserve were found between peripheral and myocardial microcirculatory beds in any of the groups (Total group: r = -0.07, SEE = 0.70, CAD: r = 0.14, SEE = 0.48, SX: r = 0.17, SEE = 0.30, DCM: r = -0.11, SEE = 0.71, NC: r = -0.19, SEE = 0.80).

CONCLUSION

No correlations between myocardial and peripheral perfusion (reserve) were found in different patient populations in the same PET session. This suggests a functional difference between peripheral and myocardial flow in the response to intravenously administered adenosine stress.

Myocardial perfusion reserve and contractile pattern after beta-blocker therapy in patients with idiopathic dilated cardiomyopathy

BACKGROUND

In Idiopathic Dilated Cardiomyopathy (IDC) an imbalance between myocardial oxygen consumption and supply has been postulated. The ensuing subclinical myocardial ischemia may contribute to progressive deterioration of LV function. beta-blocker is the therapy of choice in these patients. However, not all patients respond to the same extent. The aim of this study was to elucidate whether differences between responders and non-responders can be identified with respect to regional myocardial perfusion reserve (MPR) and contractile performance.

METHODS

Patients with newly diagnosed IDC underwent Positron Emission Tomography (PET) scanning using both (13)N-ammonia as a perfusion tracer (baseline and dipyridamole stress), and (18)F-fluoro-deoxyglucose as a metabolism tracer, and a dobutamine stress MRI. MRI and PET were repeated 6 months after maximal beta-blocker therapy. MPR (assessed by PET) as well as wall motion score (WMS, assessed by MRI) were evaluated in a 17 segment-model. Functional response to beta-blocker therapy was assigned as a stable or improved LVEF or diminished LVEF.

RESULTS

Sixteen patients were included (age 47.9 +/- 11.5 years; 12 males, LVEF 28.6 +/- 8.4%). Seven patients showed improved LVEF (9.7 +/- 3.1%), and nine patients did not show improved LVEF (-3.4 +/- 3.9%). MPR improved significantly in responders (1.56 +/- .23 to 1.93 +/- .49, P = .049), and MPR decreased in non-responders; however, not significantly (1.98 +/- .70 to 1.61 +/- .28, P = .064), but was significantly different between both groups (P = .017) after beta-blocker therapy. A significant correlation was found between change in perfusion reserve and change in LVEF: a decrease in perfusion reserve was associated with a decrease in LVEF and vice versa. Summed rest score of wall motion in responders improved from 26 to 21 (P = .022) whereas in non-responders no change was observed from 26 to 25) (P = ns). Summed stress score of wall motion in responders improved from 23 to 21 (P = .027) whereas in non-responders no change was observed from 27 to 26) (P = ns).

CONCLUSION

In IDC patients, global as well as regional improvement after initiation of beta-blocker treatment is accompanied by an improvement in regional perfusion parameters. On the other hand in IDC patients with further left ventricular function deterioration after initiation of beta-blocker therapy this is accompanied by a decrease in perfusion reserve.

Predictive value of tissue Doppler imaging for left ventricular ejection fraction, remodelling, and infarct size after percutaneous coronary intervention for acute myocardial infarction

AIMS

To investigate in ST-elevation myocardial infarction (STEMI) patients the value of tissue Doppler imaging (TDI) for an early estimation of the extent of myocardial salvage, left ventricular (LV) remodelling, and residual LV ejection fraction (LVEF).

METHODS AND RESULTS

In 50 STEMI patients hospitalized for primary percutaneous coronary intervention (PCI), we investigated whether TDI can predict LVEF, infarct size, and LV remodelling as measured by magnetic resonance imaging (MRI) at 4 months post-MI. TDI was assessed within 24 h after MI with colour-coded TDI. Systolic and diastolic velocities from the six basal myocardial segments derived from three standard apical windows were averaged as a measure of global longitudinal velocity (i.e. Sm-6 and Em-6/Am-6, respectively). Sm-6 was shown to be a significant predictor of LVEF at 4 months. In addition, Sm-6 was a significant predictor of infarct size. No significant correlations were found between Sm-6 and LV remodelling. In addition, Sm-6 appeared to be a valuable clinical tool for identification of patients with LVEF > 40% or LVEF < 40% with acceptable positive predictive values.

CONCLUSION

Sm-6 is a significant predictor of post-MI LVEF and infarct size as measured by MRI. In contrast, TDI-derived velocities do not predict LV remodelling.

Effects of rosuvastatin on coronary flow reserve and metabolic mismatch in patients with heart failure (from the CORONA Study)

In patients with heart failure (HF), statin treatment might improve myocardial perfusion, but could also have detrimental effects on myocardial metabolism. A predefined substudy of the Controlled Rosuvastatin Multinational Trial in Heart Failure (CORONA) trial sought to determine the effects of statin treatment on myocardial blood flow reserve and cardiac metabolism. Sixteen patients with HF (New York Heart Association class II or III) were randomized to rosuvastatin 10 mg/day (n = 8) or placebo treatment (n = 8). At baseline and after 6 months of treatment, nitrogen-13 ammonia at rest and after dipyridamole stress and 18-fluorodeoxyglucose positron emission tomography were performed. Rosuvastatin treatment significantly lowered total (-36%, p <0.01) and low-density lipoprotein (-47%, p <0.001) cholesterol and C-reactive protein levels (-36%, p <0.05). Myocardial perfusion reserve (ratio) changed from 1.64 +/- 0.90 to 1.30 +/- 0.37 in placebo-treated and from 1.51 +/- 0.18 to 1.55 +/- 0.34 in rosuvastatin-treated patients (p = NS). Metabolic mismatch changed from 4.25 +/- 2.37% to 4.38 +/- 3.81% in placebo-treated and from 5.13 +/- 2.75% to 3.50 +/- 2.73% in rosuvastatin-treated patients (p = NS). In conclusion, changes regarding myocardial perfusion and metabolic mismatch after 6 months of rosuvastatin treatment in patients with HF did not suggest any beneficial or adverse effects in this pilot study, although due to the small numbers of patients small effects might have been missed.

Evaluation of global left ventricular function assessment of non-fluorescent electromechanical endocardial mapping compared with biplane left ventricular contrast angiography

Background. Little is known about the diagnostic accuracy of global LV function assessment by electromechanical endocardial mapping (EEM). The aim of the present study was to determine the relationship between global left ventricular (LV) function measured by EEM and biplane left ventricular contrast angiography (LVA) after ST-elevation myocardial infarction (STEMI).Methods. Thirty-seven patients underwent LVA and EEM during routine coronary angiography four months after primary percutaneous intervention for STEMI. Global LV function parameters were available from both techniques in all patients. LVA was regarded as reference standard.Results. All procedures were carried out without adverse events. Average age was 55+/-10 years and 84% were male. EEM showed an overestimation of end-diastolic volume (EDV) and end-systolic volume (ESV) of 6.5 ml and 25.5 ml, respectively. Correlation (r) was 0.84 (p<0.001) for EDV and 0.74 (p<0.001) for ESV. Average left ventricular ejection fraction (LVEF) measured by EEM was 17.2% point (+/-11.3% point) lower compared with LVA (r=0.69, p<0.001).Conclusion. Although global functional parameters by EEM correlated well with LVA, the relatively large differences in terms of absolute values for ventricular volumes and LVEF render the two techniques non-interchangeable for global LV-function-data. (Neth Heart J 2010;18:72-77.).

Ischemic patterns assessed by positron emission tomography predict adverse outcome in patients with idiopathic dilated cardiomyopathy

BACKGROUND

Although patients with idiopathic dilated cardiomyopathy (DCM) have no coronary artery disease, regional impairment of myocardial perfusion combined with preserved metabolism has been found using positron emission tomography (PET). Our aim was to assess the prognostic relevance of PET-mismatch between stress myocardial perfusion and glucose uptake on clinical outcome in DCM.

METHODS

In 24 patients with DCM who underwent both myocardial perfusion and metabolism PET scanning, "mismatch" was assessed and the association with clinical outcome (hospitalization, mortality, and heart transplantation) was investigated.

RESULTS

Mismatch was found in 16 patients (66.7%). Univariate analysis showed that the presence of mismatch was associated with adverse outcome (P = 0.03). After adjustment for sex and age, the association remained significant with an adjusted relative risk of 10.4 (95% CI 1.1-103; P = 0.04) for death, heart transplant, or hospitalization. Univariate analysis also showed that a higher extent of mismatch was significantly associated with adverse outcome (P = 0.02). After adjusting for sex and age, the association remained significant with an adjusted relative risk of 6.5 [95% CI 1.2-36; P = 0.03] for death, heart transplantation, or hospitalization.

CONCLUSION

PET stress perfusion-metabolism mismatch, indicative for ischemia, is frequently found in DCM patients and related to a poorer outcome.

Estradiol-induced, endothelial progenitor cell-mediated neovascularization in male mice with hind-limb ischemia

We investigated whether administration of estradiol to male mice augments mobilization of bone marrow-derived endothelial progenitor cells (EPC) and incorporation into foci of neovascularization after hind-limb ischemia, thereby contributing to blood flow restoration. Mice were randomized and implanted with placebo pellets or pellets containing low-dose estradiol (0.39 mg) or high-dose estradiol (1.7 mg). Hind-limb ischemia was induced by unilateral resection of the left femoral artery 1 week after pellet implantation, then EPC mobilization and functional recovery was evaluated. EPC recruitment was assessed in mice transplanted with bone marrow from transgenic donors expressing beta-galactosidase driven by the Tie-2 promoter. EPC culture assay performed 2 weeks after pellet implantation revealed a significantly greater (p<0.05) number of circulating EPCs in the high-dose estradiol group than in the low-dose estradiol and placebo groups. At 3 and 4 weeks after induction of hind-limb ischemia, perfusion was significantly greater (p<0.05) in high-dose estradiol mice than in mice implanted with the low-dose estradiol or placebo pellets. At 1 and 4 weeks after hind-limb ischemia surgery, more bone marrow-derived EPCs, identified as beta-galactosidase-positive cells, were observed in ischemic regions from high-dose estradiol animals than in low-dose (p<0.05) or placebo groups (p<0.05). These results indicate that estradiol dose-dependently increases the levels of EPCs in peripheral blood in male animals, improves the recovery of blood flow, and decreases limb necrosis after hind-limb ischemia, and that this enhancement occurs, in part, through augmentation of EPC mobilization and greater incorporation of bone marrow-derived EPCs into foci of neovascularization.

Restenosis begets restenosis: implications for stent selection

BACKGROUND

Identifying the risk for restenosis is of critical importance in the stent selection process of patients undergoing percutaneous coronary intervention (PCI). Therefore, we sought to determine if a history of clinical recurrence (CR) after PCI increases the risk of CR after treatment of a de novo lesion in another coronary artery.

METHODS

We retrospectively analysed all 12,763 patients who underwent PCI between 1993 and 2004 and selected patients with two or more interventions in two different native vessels. These patients were divided into two groups: patients without CR, and patients with CR after the first PCI. Clinical recurrence was defined as revascular-isation of the target vessel by either PCI or CABG within one year.

RESULTS

A total of 1010 patients with two or more interventions in two different native vessels were identified: 727 patients without and 283 patients with CR after the first PCI. Baseline patient characteristics and conventional risk factors were comparable between the two groups. Patients with a history of CR had a higher risk of CR after a second intervention in a second vessel (OR=3.4, 95% CI=2.3 to 4.9). A total of 112 patients also had a third intervention in a third native vessel: 12 patients with two CR, 30 patients with one CR and 70 patients with no CR after the first two interventions. CR rates in these patients were 50, 17 and 3%, respectively (p<0.001).

CONCLUSION

Patients with a history of CR have a markedly increased risk of developing CR after a second or third PCI in a different coronary artery. Therefore, in the decision-making process on whether to use a bare metal stent or drug-eluting stent, the history of CR is a simple and powerful aid. (Neth Heart J 2008;16:376-81.).

Effects of erythropoietin after an acute myocardial infarction: rationale and study design of a prospective, randomized, clinical trial (HEBE III)

BACKGROUND

Preclinical studies have consistently shown that erythropoietin (EPO), administered after an acute myocardial infarction (AMI), reduces infarct size and improves left ventricular function. Furthermore, EPO promotes endothelial progenitor cell growth, which increases angiogenesis. A recent pilot study in patients with AMI suggested that a single bolus of EPO was safe and well tolerated.

METHODS

The HEBE III is a multicenter, prospective, randomized, open-label trial with blinded evaluation of the primary end point. The primary objective is to study the effect on left ventricular ejection fraction (LVEF) of a single bolus of EPO, administered directly after a primary percutaneous coronary intervention (PCI) for a first AMI. A total of 466 patients with thrombolysis in myocardial infarction 0/1 flow before the PCI procedure and 2/3 flow after a successful PCI are randomly assigned to either receive standard medical care or a single bolus with 60,000 IU of EPO on top of standard medical care within 3 hours of the PCI procedure. Primary end point of the study is LVEF after 6 weeks, assessed by planar radionuclide ventriculography.

IMPLICATIONS

If an improvement of LVEF with a single bolus of EPO is demonstrated, this simple approach might further improve clinical outcome of patients with AMI.

Application of PET/SPECT imaging in vascular disease

BACKGROUND

Nuclear medicine imaging differs from other imaging modalities by showing physiological processes instead of anatomical details.

OBJECTIVE

To describe the current applications of positron emission tomography (PET) and single photon emission computed tomography (SPECT) as a diagnostic tool for vascular disease as relevant to vascular surgeons.

METHODS

A literature search identified articles focussing on vascular disease and PET or SPECT using the Pubmed database. Manual cross referencing was also performed.

RESULTS

PET and SPECT may be used to assess plaque vulnerability, biology of aneurysm progression, prosthetic graft infection, and vasculitis. The ability to combine computerized tomography scanning or magnetic resonance imaging with PET or SPECT adds detailed anatomical information and enhances the potential of nuclear medicine imaging in the investigation of vascular disease.

DISCUSSION

Considerable further information will be needed to define whether and where PET or SPECT will fit in a clinical strategy. The necessary validation studies represent an exciting challenge for the future but also may require the development of interdisciplinary imaging groups to integrate expertise and optimize nuclear diagnostic potential.

Mechanisms involved in symptomatic myocardial bridging: Value of sequential testing for endothelial function, flow reserve measurements and dobutamine stress angiography

BACKGROUND

In patients with extensive myocardial bridging, evaluation of its clinical significance remains a challenge.

HYPOTHESIS

Sequential invasive testing is feasible and gives more insight into the pathophysiological mechanism of bridging-related angina.

METHODS

Twelve patients with chest pain, proven ischaemia and extensive myocardial bridging were assessed. Myocardial bridging was evaluated at rest, during intracoronary acetylcholine infusion, through coronary flow velocity and flow reserve measurements, and during dobutamine stress.

RESULTS

The mean length of the bridging segment was 24.9 mm (QCA; range 8.4-48.0 mm). Acetylcholine infusion caused severe vasospasm in two patients. In these two patients anginal symptoms were related to vasospasm and sequential testing was discontinued. In the remaining ten patients sequential testing was continued. Coronary flow reserve was normal in all patients: 3.3+/-0.6. In six patients reliable quantitative measurements could be performed during dobutamine stress. The mean systolic diameter of the bridging segment was 1.6+/-0.4 at baseline and 1.3+/-0.3 during dobutamine stress (mean of differences 0.38 (95% CI 0.1-0.7)). The difference between the diastolic and systolic diameter in the bridging segment increased from 0.3+/-0.2 mm at baseline to 1.0+/-0.5 mm during dobutamine infusion (mean of differences 0.6 (95% CI 0.3 to 0.9)).

CONCLUSION

Sequential testing for bridging is feasible and may disclose endothelial dysfunction or spasm as an underlying mechanism in a minority of patients. Coronary flow reserve was preserved. Dobutamine stress unmasked further lumen reduction and may give further insight into the clinical significance of myocardial bridging in individual patients. (Neth Heart J 2008;16:10-5.).

Severe Myocardial Fibrosis Caused by a Deletion of the 5’ End of the Lamin A/C Gene

OBJECTIVES

The goal of this study was to identify the underlying gene defect in a family with inherited myocardial fibrosis.

BACKGROUND

A large family with an autosomal dominantly inherited form of myocardial fibrosis with a highly malignant clinical outcome has been investigated. Because myocardial fibrosis preceded the clinical and echocardiographic signs, we consider the disease to be a hereditary form of cardiac fibrosis.

METHODS

Twenty-five family members were clinically evaluated, and 5 unaffected and 8 affected family members were included in a genome-wide linkage study.

RESULTS

The highest logarithm of the odds (LOD) score (LOD = 2.6) was found in the region of the lamin AC (LMNA) gene. The LMNA mutation analysis, both by denaturing gradient gel electrophoresis and sequencing, failed to show a mutation. Subsequent Southern blotting, complementary deoxyribonucleic acid sequencing, and multiplex ligation-dependent probe amplification analysis, however, revealed a deletion of the start codon-containing exon and an adjacent noncoding exon. In vitro studies demonstrated that the deletion results in the formation of nuclear aggregates of lamin, suggesting that the mutant allele is being transcribed.

CONCLUSIONS

This novel LMNA deletion causes a distinct, highly malignant cardiomyopathy with early-onset primary cardiac fibrosis likely due to an effect of the shortened mutant protein, which secondarily leads to arrhythmias and end-stage cardiac failure.

Stem cell-related cardiac gene expression early after murine myocardial infarction

OBJECTIVE

Clinical experimental stem cell therapy after myocardial infarction appears feasible, but its use has preceded the understanding of the working mechanism. The ischemic recipient cardiac environment is determinative for the attraction and subsequent fate of stem cells. Here, we studied expression levels of genes that are anticipated to be essential for adequate stem cell-based cardiac repair at various time-points during the 1 month period following myocardial infarction (MI).

METHODS

Gene expression in the hearts of mice that underwent MI by permanent or transient (30 min) ligation of the coronary artery was monitored using quantitative RT-PCR analysis of mRNA isolated from whole heart sections as well as from specific, laser micro-dissected, regions of sections. Protein expression was performed by immunohistochemical stainings and Western blot analysis.

RESULTS

Many inflammatory genes were highly expressed for at least 1 week after MI. The expression of pro-angiogenic genes such as bFGF, VEGF-A and VEGF-R2 changed only marginally post-MI. Markers used to test stem cell gene expression remained unchanged post-MI with the exception of G-CSF and GM-CSF, which are genes that are also known to enhance the inflammatory response. Analysis of micro-dissected regions revealed that SDF-1, SCF (both stem cell attractants) and VEGF-R2 (involved in angiogenesis) gene expression was slightly decreased especially in the infarcted region.

CONCLUSION

Genes that are generally considered to participate in stem cell-related processes and angiogenesis were not upregulated after MI, whereas the inflammatory gene expression dominated. Modulation of this imbalance might be of value for stem cell-mediated therapy.

Quantification of global left ventricular function: comparison of multidetector computed tomography and magnetic resonance imaging. a meta-analysis and review of the current literature

Cardiac morbidity and mortality are closely related to cardiac volumes and global left ventricular (LV) function, expressed as left ventricular ejection fraction. Accurate assessment of these parameters is required for the prediction of prognosis in individual patients as well as in entire cohorts. The current standard of reference for left ventricular function is analysis by short-axis magnetic resonance imaging. In recent years, major extensive technological improvements have been achieved in computed tomography. The most marked development has been the introduction of the multidetector CT (MDCT), which has significantly improved temporal and spatial resolutions. In order to assess the current status of MDCT for analysis of LV function, the current available literature on this subject was reviewed. The data presented in this review indicate that the global left ventricular functional parameters measured by contemporary multi-detector row systems combined with adequate reconstruction algorithms and post-processing tools show a narrow diagnostic window and are interchangeable with those obtained by MRI.

Interleukin 10: a new risk marker for the development of restenosis after percutaneous coronary intervention

Genetic factors appear to be important in the process of restenosis after percutaneous coronary intervention (PCI), as well as in inflammation, a pivotal factor in restenosis. An important mediator in the inflammatory response is interleukin (IL)-10. Our aim was to study whether genetic variants in IL-10 predispose to the risk of restenosis. The GENetic DEterminants of Restenosis (GENDER) study included 3104 patients treated with successful PCI. Target vessel revascularization (TVR) was chosen as primary end point. Genotyping of the -2849G/A, -1082G/A, -592C/A and +4259A/G polymorphisms of the IL-10 gene was performed by MassArray platform. After adjusting for clinical variables, three polymorphisms significantly increased the risk of restenosis (-2849AA: relative risk (RR), 1.7, 95% confidence interval (CI), 1.2-2.5; -1082AA: RR, 1.4, 95% CI, 1.1-1.8 and +4259GG: RR, 2.0, 95% CI, 1.4-2.8). To further exclude possible involvement of neighboring genes due to LD in the IL-10 locus, additional polymorphisms were genotyped. The results reveal that association of the IL-10 gene with restenosis is independent of flanking genes. Our findings demonstrate that IL-10 is associated with restenosis and therefore support the hypothesis that anti-inflammatory genes also may be involved in developing restenosis. Furthermore, they may provide a new targeting gene for drug-eluting stents.

The benefit of 64-MDCT prior to invasive coronary angiography in symptomatic post-CABG patients

PURPOSE

The purpose of this study is to assess the diagnostic accuracy of 64-MDCT in symptomatic patients after CABG and to explore the advantages of the 64-MDCT results on the CAG procedure.

MATERIAL AND METHODS

From December 2004 until August 2005, 34 post-CABG patients (29 men, mean age 63.5 +/- 8.5 years) with 69 coronary artery bypass grafts were scanned on a 64-MDCT (Somatom Sensation 64, Siemens AG, Forchheim, Germany) prior to CAG. Angiograms and 64-MDCT images were evaluated for the existence of occlusions or significant stenosis (>or=50% lumen reduction) in bypass grafts and native coronary arteries.

RESULTS

64-MDCT had a sensitivity, a specificity, and a diagnostic accuracy of 100% for occlusion detection. For stenosis detection, sensitivity was 100%, specificity 98.7% and diagnostic accuracy 98.7%. For detecting significant stenosis in native coronary arteries, 64-MDCT had a sensitivity of 80.0%, specificity of 90.8%, and a diagnostic accuracy of 87.1%. Seventeen patients (50.0%) did not need invasive treatment, 14 patients (41.2%) underwent a percutaneous coronary intervention (PCI), and 3 patients (8.8%) underwent surgery. Treatment advice based on 64-MDCT was correct in 88.2% of patients and when 64-MDCT results would have been known 58.8% of diagnostic CAG procedures could have been prevented.

CONCLUSION

In conclusion, 64-MDCT has a high diagnostic accuracy in detecting bypass graft stenosis and occlusions, and 64-MDCT based treatment advice was correct in 88.2% of patients.

Echocardiographic and electron beam tomographic assessment of stenosis in patients with aortic valve disease: gradient versus valve area

BACKGROUND

Transthoracic echocardiography (TTE) is routinely used to evaluate aortic valve stenosis. However, it does not give reliable results in every patient. There is growing interest in electron-beam tomography (EBT) as a noninvasive cardiac imaging technique. The usefulness of EBT to evaluate aortic stenosis has yet to be evaluated.

AIM

To compare EBT with TTE in assessing severity of aortic stenosis.

METHODS

In total 47 patients (18 females, 29 males) underwent a contrast-enhanced EBT scan and TTE within 6±20 days. The calcium score of the aortic valve was determined and the aortic valve area (AVA) was measured by planimetry. A complete TTE study, during which the peak pressure gradient across the aortic valve was measured, was performed in all patients by an experienced sonographer.

RESULTS

There was a significant correlation between AVA assessed by EBT and peak pressure gradient (r=-0.38, p=0.009). The calcium score of the aortic valve assessed by EBT correlated with peak pressure gradient (r=0.48, p=0.001).

CONCLUSION

EBT is a useful noninvasive method to evaluate the severity of aortic stenosis. It holds the possibility of assessing the AVA as well as quantification of the degree of calcification.

Circulating CD34+ progenitor cells modulate host angiogenesis and inflammation in vivo

Within the phenotypically and functionally heterogeneous group of circulating progenitor cells (CPC), a subclass of cells with vascular repair potential have been identified. These CPC are detected and isolated based on single or combined expression of CD34, CD133 and VEGFR-2, and referred to as endothelial progenitor cells. Here we asked whether CPC subsets defined by single expression of these markers exhibit functional heterogeneity. As functional parameters, we chose the capacity of CPC to differentiate into endothelial cells. Moreover, we studied their role in remodeling by recruitment of inflammatory cells, an aspect that has been little explored. We established an in vivo model in which the intrinsic functional capacity of these human CPC subsets was studied. Human CD34+ CPC, but not CD133+ or VEGFR-2+ CPC, seeded in Matrigel pellets and transplanted subcutaneously in a nude mouse host, contributed little to donor-derived neovascularization. However, host angiogenesis in the Matrigel implant, as demonstrated by the presence of capillaries containing erythrocytes and expressing mouse CD31, was strong in response to implantation of human CD34+ CPC and significantly lower in response to the other two CPC subsets. Moreover, the CD34+ CPC subset was significantly superior to CD133+ CPC and VEGFR-2+ CPC in the recruitment of host monocytes/macrophages. These three CPC populations were further dissected into seven discrete subsets, based on three-parameter flow cytometry analysis of combined expression patterns of CD34, CD133 and VEGFR-2. In conclusion, in our system, CD34+ CPC contribute marginally to neovascularization by differentiation but are potent regulators of the host angiogenic and pro-inflammatory response, suggesting a possible role for these cells in the remodeling of vascular lesions.

Treatment with Intramuscular Vascular Endothelial Growth Factor Gene Compared with Placebo for Patients with Diabetes Mellitus and Critical Limb Ischemia: A Double-Blind Randomized Trial

Despite advances in revascularization techniques, limb salvage and relief of pain cannot be achieved in many diabetic patients with diffuse peripheral vascular disease. Our objective was to determine the effect of intramuscular administration of phVEGF165 (vascular endothelial growth factor gene-carrying plasmid) on critical limb ischemia (CLI) compared with placebo (0.9% NaCl). A double-blind, placebo-controlled study was performed in 54 adult diabetic patients with CLI. The primary end point was the amputation rate at 100 days. Secondary end points were a 15% increase in pressure indices (ankle-to-brachial index and toe-to-brachial index), clinical improvement (skin, pain, and Quality of Life score), and safety. In patients (n=27) treated with placebo versus phVEGF165-treated patients (n=27) the following results were found: 6 amputations versus 3 (p=not significant [NS]); hemodynamic improvement in 1 versus 7 (p=0.05); improvement in skin ulcers, 0 versus 7 (p=0.01); decrease in pain, 2 versus 5 (p=NS); and overall, 3 versus 14 responding patients (p=0.003). No grade 3 or 4 adverse effects were seen in these patients. We conclude that this small, randomized gene therapy study failed to meet the primary objective of significant amputation reduction. However, significant and meaningful improvement was found in patients treated with a VEGF165-containing plasmid. There were no substantial adverse events.

The effect of electrical neurostimulation on collateral perfusion

BACKGROUND/OBJECTIVES

Clinical data have shown that electrical neurostimulation may improve myocardial ischaemia. Our aim was to investigate the possible effect of electrical neurostimulation on collateral perfusion.

METHODS

Thirty patients with stable angina and significant single-vessel coronary artery disease scheduled for elective percutaneous coronary intervention (PCI) were randomised into three groups. In all patients two balloon inflations were performed, one for predilatation of the lesion, the second for stent delivery. Group one received active neurostimulation during the first ischaemic episode (predilatation), group two during the second ischaemic episode (stent delivery), and group three received placebo neurostimulation continuously. During both ischaemic episodes the collateral flow index was determined.

RESULTS

No significant differences were found between active, inactive or placebo neurostimulation. In a post-hoc analysis the patients were stratified for presence or absence of significant collaterals. In patients with pre-existing significant collaterals, the collateral flow index was significantly higher during active neurostimulation compared with inactive neurostimulation (p=0.012) and compared with the merged inactive and placebo groups (p=0.011).

CONCLUSION

The present data show no effect of electrical neurostimulation on collateral perfusion in patients with single-vessel disease. In a post-hoc analysis in patients with evidence of collaterals, defined as a collateral flow index of >0.24, an increase in collateral perfusion was found during electrical neurostimulation.

Increased inflammatory response and neovascularization in reperfused vs. non-reperfused murine myocardial infarction

INTRODUCTION

Fundamental knowledge of the inflammatory response after myocardial infarction (MI) is indispensable for intervention toward cardiac regeneration. Although reperfusion is preferred as clinical therapy, for basic research, also permanent ligation MI models are widely used.

METHODS

In this report, we pathohistologically compared the kinetics of the inflammatory and angiogenic response after MI induced by permanent ligation or ligation followed by reperfusion of the left anterior descending coronary artery in mice.

RESULTS

Permanent ligation resulted in a higher mortality rate accompanied by increased left ventricular dilatation and more progressive wall thinning. However, reperfused infarcts showed higher inflammatory cell influx. Neutrophil numbers were higher after reperfusion post-MI, although their presence was prolonged after ligation. Also, the number of macrophages after reperfusion was continuously higher, but the course of macrophage influx was comparable in both models. The number of lymphocytes was low in both models. Only the peak in myofibroblast numbers at 7 days was higher after ligation than after reperfusion. Moreover, cardiomyocyte remnants were cleared faster, and collagen deposition started earlier after reperfusion. In addition, reperfusion resulted in an increased angiogenic response, as was reflected in increased numbers of medium-sized and large vessels at 7 and 14 days post-MI.

CONCLUSION

We show less adverse remodeling together with a higher presence of inflammatory cells and enhanced neovascularization in reperfused MI. These differences between non-reperfused and reperfused MI should be taken into consideration for experimental use of MI models.

Angioplasty of the left main coronary artery: Mid-term follow-up at University Medical Centre Groningen

BACKGROUND

Coronary angioplasty is being increasingly performed in complex lesions of the unprotected and protected left main (LM) coronary artery.

OBJECTIVES

To assess the impact of patient and operator related clinical variables of success and to evaluate the subsequent mid-term effects of percutaneous treatment of LM coronary stenosis.

METHODS

In a tertiary referral, high-volume angioplasty centre a total of 118 consecutive surgical and nonsurgical patients with protected and unprotected LM lesions were treated and evaluated in a retrospective observational study.

RESULTS

There were 57 protected and 61 unprotected patients, including 13 patients with an acute myocardial infarction (AMI). Mean age was 67 years (range 33-90). The length of the stenotic segment was 4.8±2.3 mm, mean lumen diameter 1.1±0.6 mm and percentage diameter stenosis 63.6±14.6%. There were seven (5.9%) in-hospital cardiac deaths which presented with AMI and cardiogenic shock. All seven patients had unprotected LM lesions. Average follow-up was eight months (range 1 to 36 months). Major adverse cardiac events (MACE) during follow-up comprised eight (6.8%) cardiac deaths, three (2.5%) myocardial infarctions, eight (6.8%) subjects with coronary bypass surgery and 16 (13.6%) repeated angioplasties. The total event rate (MACE, n=43) at the end of the follow-up period was 36.4%. There were more MACE in the unprotected group than in the protected group (41 vs. 31.6%, p<0.05).

CONCLUSION

This study supports prior data on LM angioplasty. LM stenting in AMI, however, showed less favourable in-hospital and late outcome.

[Delirium attributed to the use of metoprolol]

A 53-year-old man with a known history of alcohol abuse was admitted to hospital after a minor collapse. He had a laceration to the forehead and three rib fractures. Laboratory blood-analysis showed raised non-cholestatic liver-enzyme levels suggesting alcohol-abuse. On history taking the patient was shown to have been suffering from personality changes and multiple hallucinogenic episodes for the previous two years. He had been seen and evaluated by a neurologist to that effect. The patient's family had accepted the situation and thought of it as dementia, probably caused by alcohol abuse. He had been treated for atrial flutter and was taking acenocoumerol, atorvastatin, quinapril and metoprolol 50 mg twice daily as medication. During admission the patient appeared to be suffering from a delirium with complex visual and auditory hallucinations, for which he was given haloperidol. Revision of medication use led to the stopping of metoprolol, which had been started two years earlier. Within 24 hours the delirium had disappeared completely. There was spontaneous fall in the liver enzymes. At his last follow-up, the patient had had no psychiatric symptoms for 6 months. The relationship between stopping metoprolol and the disappearance of the psychosis appeared to be a causal one and this is supported by the limited literature available on this subject.

Myocardial viability assessment: poor correlation between electromechanical cardiac mapping and positron emission tomography in severe coronary artery disease

BACKGROUND

An intracardial electromechanical mapping system has recently been introduced which offers the ability to perform on-line myocardial viability assessment in the catheterisation laboratory. Only a small number of studies have been performed to validate this potentially very useful technique.

AIM

We sought to assess the correlation between viability assessment performed with both positron emission tomography (PET) and electromechanical cardiac mapping (EMM) in patients suffering from severe coronary artery disease, since PET is considered the golden standard in myocardial viability assessment.

METHODS

Patients undergoing both EMM and PET analysis were systematically scanned for viability assessment. EMM analysis was performed for both linear local shortening and unipolar voltage. PET analysis consisted of dipyridamole stress and fluoro-deoxy-d-glucose (FDG) measurements. All data were converted to nine-segment bull's-eye maps to allow comparison. One single operator analysed all the data, blinded for clinical status.

RESULTS

34 patients suffering from severe coronary artery disease underwent both PET and EMM analysis. In total 253 EMM segments had more than four contact points and could be used for analysis. Unipolar voltage showed a trend towards lower values in infarcted segments; however, linear local shortening did not show any correlation.

CONCLUSION

In this study viability assessment by EMM did not correspond with PET analysis. Although the advantage of having some form of online myocardial assessment is evident, operators should bare in mind that the quantitative EMM measurements are not an absolute substitute for nuclear imaging.

Anaemia predicts cardiovascular events in patients with stable coronary artery disease

BACKGROUND

Anaemia is an independent risk factor for cardiovascular (CV) events in patients with heart failure and patients with chronic kidney disease. The effect of anaemia on CV outcomes in patients with coronary artery disease (CAD) remains unclear. Therefore, we investigated the prognostic value of anaemia in this group of patients.

METHODS

Patients with stable angina pectoris, referred for a first diagnostic coronary angiography, were eligible for this study. Only subjects with significant coronary artery disease (>50% luminal narrowing) were used for analysis (n=143). Cardiovascular events were defined as cardiovascular death, acute myocardial infarction and hospitalisation for unstable angina pectoris. Anaemia was defined according to WHO criteria as haemoglobin level ≤8 mmol/l in men and ≤7.5 mmol/l in women.

RESULTS

The mean age of the population was 61.5±9.4 years. During follow-up (44±19 months), 19 CV events occurred. The diagnosis of anaemia predicted CV events, even when adjusted for other risk factors (hazard ratio 5.73, 95% confidence interval 1.49-22.13, p=0.01). In univariate analysis, serum erythropoietin levels predicted CV outcomes (p<0.05); however, this association was lost when adjusted for haemoglobin concentration.

CONCLUSION

Anaemia is associated with worse outcome in patients with established CAD and could be used as a prognostic indicator in this group of patients.

Signaling factors in stem cell-mediated repair of infarcted myocardium

Myocardial infarction leads to scar formation and subsequent reduced cardiac performance. The ultimate therapy after myocardial infarction would pursue stem cell-based regeneration. The aim of stem cell-mediated cardiac repair embodies restoration of cardiac function by regeneration of healthy myocardial tissue, which is accomplished by neo-angiogenesis and cardiogenesis. A major reservoir of adult autologous stem cells distal from the heart is the bone marrow. Adequate regulation of signaling between the bone marrow, the peripheral circulation and the infarcted myocardium is important in orchestrating the process of mobilization, homing, incorporation, survival, proliferation and differentiation of stem cells, that leads to myocardial regeneration. In this review, we discuss key signaling factors, including cytokines, chemokines and growth factors, which are involved in orchestrating the stem cell driven repair process. We focus on signaling factors known for their mobilizing and chemotactic abilities (SDF-1, G-CSF, SCF, IL-8, VEGF), signaling factors that are expressed after myocardial infarction involved in the patho-physiological healing process (TNF-alpha, IL-8, IL-10, HIF-1alpha, VEGF, G-CSF) and signaling factors that are involved in cardiogenesis and neo-angiogenesis (VEGF, EPO, TGF-beta, HGF, HIF-1alpha, IL-8). The future therapeutic application and capacity of secreted factors to modulate tissue repair after myocardial infarction relies on the intrinsic potency of factors and on the optimal localization and timing of a combination of signaling factors to stimulate stem cells in their niche to regenerate the infarcted heart.

Assessment of coronary artery bypass graft patency by multidetector computed tomography and electron-beam tomography

This case report describes the use of retrospectively ECG-gated 16-slice multidetector computed tomography (MDCT) and electron-beam tomography (EBT) for assessing bypass graft patency in two patients with recurrent angina after coronary artery bypass graft surgery. The results of each tomographic modality were compared to the findings of traditional coronary angiography. In the first patient MDCT showed occlusion of the left internal mammary artery (LIMA) and saphenous vein graft after the second anastomosis. Coronary angiography confirmed these findings. In the second patient EBT showed patency of the LIMA and saphenous vein graft. After the first anastomosis of the saphenous vein graft, the connected vessel filled poorly. Coronary angiography confirmed both grafts to be patent, and detected an occlusion distal to the first anastomosis. These findings support the evidence that both MDCT and EBT are suitable techniques for establishing bypass graft patency by non-invasive means.

Reduction of endothelial dysfunction following VEGF gene therapy

BACKGROUND/OBJECTIVES

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. VEGF gene therapy improves perfusion of ischaemic myocardium in experimental models and possibly in patients with end-stage coronary artery disease. In addition to its proliferative and migratory effect on endothelial cells, it also activates and upregulates eNOS. Therefore, we investigated coronary endothelium-dependent vasodilatation in patients before and after VEGF gene therapy.

METHODS

The effect of intracoronary acetylcholine infusion on coronary diameter was assessed at baseline and after three months of follow-up in patients with end-stage coronary artery disease treated with VEGF gene and in controls scheduled for elective PTCA (acetylcholine test at diagnostic angiography and before a subsequently scheduled PTCA).

RESULTS

Eight out of ten VEGF patients experienced a reduction in anginal symptoms. Angiographic evidence for improved collateral filling was evident in two out of six patients. The vasoconstrictive response to acetylcholine was partly converted into dilatation. In contrast, the acetylcholine response in control patients remained vasoconstrictive.

CONCLUSION

VEGF gene therapy has an important beneficial effect on the functional characteristics of the myocardial vascular network. Therefore, this therapy can potentially play an important role in all stages of the atherosclerotic process.

Renin-Angiotensin System Intervention to Prevent In-Stent Restenosis

The occurrence of in-stent restenosis is a major drawback of percutaneous transluminal coronary angioplasty with stent placement. Target vessel revascularization is necessary in 15% of patients who receive a stent. Recent advances in the development of drug-eluting stents have reduced these numbers tremendously. However refinement of antirestenotic therapies remains obligatory. The emerging interest in more physiological antirestenotic therapies might unchain an interest in the well-known inhibitors of the rennin-angiotensin system (RAS), the angiotensin-converting enzyme inhibitors, and the angiotensin II type I receptor blockers. Contradictory results overshadow the discussion of whether intervention in the RAS could prevent in-stent restenosis. This review discusses the pathophysiology of in-stent restenosis, the role of the RAS in in-stent restenosis, and the possible role of RAS intervention in the prevention of in-stent restenosis.

The role of coronary endothelial function testing in patients suspected for angina pectoris

Coronary vasomotor function plays an important role in onset and progression of coronary artery disease. Suwaidi [Circulation 101 (2000) 948] and Schächinger [Circulation 101 (2000) 1899] demonstrated that vasomotor dysfunction has a significant impact on events in patients with minimal coronary artery disease. Endothelial specific testing can be performed in coronary as well as peripheral arteries. However, non-coronary tests have a low correlation with the coronary vasomotor response, as assessed by acetylcholine. In large clinical prospective placebo-controlled trials, angiotensin-converting enzyme (ACE) inhibitors and lipid-lowering drugs reduce morbidity and mortality after myocardial infarction or myocardial infarction-induced heart failure. The same drugs restore endothelial dysfunction after myocardial infarction, as was demonstrated in small experimental and clinical studies. Recent studies in patients with coronary artery disease showed a relation with endothelial dysfunction and the occurrence of adverse coronary events. For this reason, it is important to develop methods to evaluate endothelial function.