Cardiomyopathie de tako-tsubo: une entité clinique rare et méconnue [Tako-tsubo cardiomyopathy: a rare and badly known clinical entity]

Tako-tsubo cardiomyopathy or "transient left ventricular (LV) apical ballooning" clinically presents like acute myocardial infarction without angiographic stenosis on coronary angiogram and a transient (reversible) LV apical ballooning. We discuss here about a 56-year-old woman complains of first constrictive chest pain with ST elevation in leads V2-V6 and minimal enzymatic release. Coronary angiogram demonstrates vessels without stenosis and the left ventriculogram an extensive LV apical wall motion abnormalities. LV dysfunction will only be transient since 24 hours after admission echographic images demonstrate quite complete recovery of LV systolic function. The pain disappears 12 hours after admission and the creatine kinase level normalize after 48 hours.

Sex differences in atheroma burden and endothelial function in patients with early coronary atherosclerosis.

AIMS: Women and men have different clinical presentations and outcomes in coronary artery disease (CAD). We tested the hypothesis that sex differences may influence coronary atherosclerotic burden and coronary endothelial function before development of obstructive CAD. METHODS AND RESULTS: A total of 142 patients (53 men, 89 women; mean +/- SD age, 49.3 +/- 11.7 years) with early CAD simultaneously underwent intravascular ultrasonography and coronary endothelial function assessment. Atheroma burden in the left main and proximal left anterior descending (LAD) arteries was significantly greater in men than women (median, 23.0% vs. 14.1%, P = 0.002; median, 40.1% vs. 29.3%, P = 0.001, respectively). Atheroma eccentricity in the proximal LAD artery was significantly higher in men than women (median, 0.89 vs. 0.80, P = 0.04). The length of the coronary segments with endothelial dysfunction was significantly longer in men than women (median, 39.2 vs. 11.1 mm, P = 0.002). In contrast, maximal coronary flow reserve was significantly lower in women than men (2.80 vs. 3.30, P < 0.001). Sex was an independent predictor of atheroma burden in the left main and proximal LAD arteries (both P < 0.05) by multivariate analysis. CONCLUSION: Men have greater atheroma burden, more eccentric atheroma, and more diffuse epicardial endothelial dysfunction than women. These results suggest that men have more severe structural and functional abnormalities in epicardial coronary arteries than women, even in patients with early atherosclerosis, which may result in the higher incidence rates of CAD and ST-segment myocardial infarction in men than women.

Significance of an isolated new right bundle branch block in a patient with chest pain.

Chest pain is a common presenting symptom in emergency departments, and a typical manifestation of acute myocardial infarction (AMI). Recognition of ECG changes in AMI is essential for timely diagnosis and treatment. Right bundle branch block (RBBB) may be an isolated sign of AMI, and was previously considered as a criterion for fibrinolytic therapy. Since the most recent European Society of Cardiology and American Heart Association guidelines in 2013, RBBB alone is no longer considered a diagnostic criterion of AMI, even if it occurs in the context of acute chest pain, as RBBB does not usually interfere with the interpretation of ST-segment alteration. Our case illustrates an acute septal myocardial infarction with an isolated RBBB, and thus the importance of recognising this pattern in order to permit timely diagnosis and treatment.

Angiotensin II favors progression to heart failure in diabetic hearts: role of myocardial fatty acid oxidation downregulation

Purpose: Diabetic myocardium is particularly vulnerable to develop heart failure in response to chronic stress conditions including hypertension or myocardial infarction. We have recently observed that angiotensin II (Ang II)-mediated downregulation of the fatty acid oxidation pathway favors occurrence of heart failure by myocardial accumulation of lipids (lipotoxicity). Because diabetic heart is exposed to high levels of circulating fatty acid, we determined whether insulin resistance favors development of heart failure in mice with Ang II-mediated myocardial remodeling.Methods: To study the combined effect of diabetes and Ang II-induced heart remodeling, we generated leptin-deficient/insulin resistant (Lepob/ob) mice with cardiac targeted overexpression of angiotensinogen (TGAOGN). Left ventricular (LV) failure was indicated by pulmonary congestion (lung weight/tibial length>+2SD of wild-type mice). Myocardial metabolism and function were assessed during in vitro isolated working heart perfusion.Results: Forty-eight percent of TGAOGN mice without insulin resistance exhibited pulmonary congestion at the age of 6 months associated with increased myocardial BNP expression (+375% compared with WT) and reduced LV power (developed pressure x cardiac output; -15%). The proportion of mice presenting heart failure was markedly increased to 71% in TGAOGN mice with insulin resistance (TGAOGN/Lepob/ob). TGAOGN/Lepob/ob mice with heart failure exhibited further increase of BNP compared with failing non-diabetic TGAOGN mice (+146%) and further reduction of cardiac power (-59%). Mice with insulin resistance alone (Lepob/ob) did not exhibit signs of heart failure or LV dysfunction. Myocardial fatty acid oxidation measured during in vitro perfusion was markedly increased in non-failing hearts from Lepob/ob mice (+380% compared with WT) and glucose oxidation decreased (-72%). In contrast, fatty acid and glucose oxidation did not differ from Lepob/ob mice in hearts from TGAOGN/Lepob/ob mice without heart failure. However, both fatty acid and glucose oxidation were markedly decreased (-47% and -48%, respectively, compared with WT/Lepob/+) in failing hearts from TGAOGN/Lepob/ob mice. Reduction of fatty acid oxidation was associated with marked reduction of protein expression of a number of regulatory enzymes implied in fatty acid oxidation.Conclusions: Insulin resistance favors the progression to heart failure during chronic exposure of the myocardium to Ang II. Our results are compatible with a role of Ang II-mediated downregulation of fatty acid oxidation, potentially promoting lipotoxicity.

Long-term prognostic value of single-photon emission computed tomography myocardial perfusion imaging in diabetic patients with and without coronary artery disease

Keywords Diabetes mellitus; coronary artery disease; myocardial ischemia; prognostic value; single-photon emission computed tomography myocardial perfusion imaging Summary Aim: To determine the long-term prognostic value of SPECT myocardial perfusion imaging (MPI) for the occurrence of cardiovascular events in diabetic patients. Methods: SPECT MPI of 210 consecutive Caucasian diabetic patients were analysed using Kaplan-Meier event-free survival curves and independent predictors were determined by Cox multivariate analyses. Results: Follow-up was complete in 200 (95%) patients with a median period of 3.0 years (0.8-5.0). The population was composed of 114 (57%) men, age 65±10 years, 181 (90.5%) type 2 diabetes mellitus, 50 (25%) with a history of coronary artery disease (CAD) and 98 (49%) presenting chest pain prior to MPI. The prevalence of abnormal MPI was 58%. Patients with a normal MPI had neither cardiac death, nor myocardial infarction, independently of a history of coronary artery disease or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal MPI (p<.0001), followed by history of CAD (Hazard Ratio (HR)= t 5.9, p=0.0001), diabetic retinopathy (HR=10.0, p=0.001) and inability to exercise (HR=7.7, p=0.02). Patients with normal 1VIPI had a low revascularisation rate of 2.4% during the follow-up period. Compared to normal MPI, cardiovascular events increased 5.2 fold for reversible defects, 8.5 fold for fixed defects and 20.1 fold for the association of both defects. Conclusion: Diabetic patients with normal MPI had an excellent prognosis independently of history of CAD. On the opposite, an abnormal MPI led to a > 5 fold increase in cardiovascular events. This emphasizes the value of SPECT MPI in predicting and risk-stratifying cardiovascular events in diabetic patients. Mots-Clés Diabète; maladie coronarienne; ischémie myocardique; valeur pronostique; tomoscintigraphie myocardique de perfusion par émission monophotonique Résumé Objectifs: Déterminer la valeur pronostique à long terme de la tomoscintigraphie myocardique de perfusion (TSMP) chez les patients diabétiques pour prédire les événements cardiovasculaires (ECV). Méthodes: Etude de 210 diabétiques caucasiens consécutifs référés pour une TSMP. Les courbes de survie ont été déterminées par Kaplan-Meier et les facteurs prédictifs indépendants par analyses multivariées de type Cox. Résultats: Le suivi a été complet chez 200 (95%) patients avec une durée médiane de 3.0 ans (0.8-50). La population était composée de 114 (57%) hommes, âge moyen 65±10 ans, avec 181 (90.5%) diabète de type 2, 50 (25%) antécédents de maladie coronarienne (AMC) et 98 (49%) patients connus pour un angor avant la TSMP. La prévalence de TSMP anormales était de 58%. Aucun décès d'origine cardiaque ou infarctus du myocarde n'est survenu chez les patients avec une TSMP normale, ceci indépendamment de leurs AMC et des douleurs thoraciques. Les facteurs prédictifs indépendants pour les ECV sont une TSMP anormale (p<.0001), les AMC (Hazard Ratio (HR)=15.9, p-0.0001), suivi de la rétinopathie diabétique (HR-10.0, p=0.001) et de l'incapacité à effectuer un exercice (HR=7.7, p=0.02). Les patients avec une TSMP normale ont présenté un taux de revascularisations de 2.4%. La présence de défauts mixtes accroît le risque d'ECV de 20.1 fois, les défauts fixes de 8.5 fois et les défauts réversibles de 5.2 fois comparés aux sujets avec une TSMP normale. Conclusion: Les patients diabétiques, coronariens ou non, avec une tomoscintigraphie myocardique de perfusion normale ont un excellent pronostique. A l'opposé, une TSMP anormale est associée à une augmentation du risque d'ECV de plus de 5 fois. Ceci confirme l'utilité de la TSMP dans la stratification du risque chez les patients diabétiques.

Neuropeptide Y infusion decreases plasma renin activity in postmyocardial infarction rats.

We wished to determine if chronic neuropeptide Y (NPY) infusion (1 ng/min for 1 week by Alzet minipump) could decrease plasma renin activity (PRA) and norepinephrine (NE) in a rat myocardial infarction (MI) model of moderate compensated congestive heart failure (CHF). CHF was produced by prior (6-8 weeks) ligation of the left coronary artery; control rats were sham-operated. Carotid arterial blood was drawn for PRA and NE in conscious unrestrained rats that had been instrumented 24 h earlier. MI rats had increased PRA as compared with sham-operated rats [8.73 +/- 1.27 vs. 5.10 +/- 0.91 ng angiotensin (AI) I/ml.h, mean +/- SE]. During chronic NPY infusion, PRA was reduced to normal in the MI group (4.78 +/- 0.91) but was not affected in the sham group (5.65 +/- 0.51). Plasma NE was altered similarly, but the changes did not reach statistical significance. These data suggest that NPY has the capacity to restrain renin release in moderate compensated CHF.

SPECT myocardial perfusion imaging: long-term prognostic value in diabetic patients with and without coronary artery disease.

AIM: To determine the long-term prognostic value of SPECT myocardial perfusion imaging (MPI) for the occurrence of cardiovascular events in diabetic patients. PATIENTS, METHODS: SPECT MPI of 210 consecutive Caucasian diabetic patients were analysed using Kaplan-Meier event-free survival curves and independent predictors were determined by Cox multivariate analyses. RESULTS: Follow-up was complete in 200 (95%) patients with a median period of 3.0 years (0.8-5.0). The population was composed of 114 (57%) men, age 65 +/- 10 years, 181 (90.5%) type 2 diabetes mellitus, 50 (25%) with a history of coronary artery disease (CAD) and 98 (49%) presenting chest pain prior to MPI. The prevalence of abnormal MPI was 58%. Patients with a normal MPI had neither cardiac death, nor myocardial infarction, independently of a history of coronary artery disease or chest pain. Among the independent predictors of cardiac death and myocardial infarction, the strongest was abnormal MPI (p < 0.0001), followed by history of CAD (Hazard Ratio (HR) = 15.9; p = 0.0001), diabetic retinopathy (HR = 10.0; p = 0.001) and inability to exercise (HR = 7.7; p = 0.02). Patients with normal MPI had a low revascularisation rate of 2.4% during the follow-up period. Compared to normal MPI, cardiovascular events increased 5.2 fold for reversible defects, 8.5 fold for fixed defects and 20.1 fold for the association of both defects. CONCLUSION: Diabetic patients with normal MPI had an excellent prognosis independently of history of CAD. On the opposite, an abnormal MPI led to a >5-fold increase in cardiovascular events. This emphasizes the value of SPECT MPI in predicting and risk-stratifying cardiovascular events in diabetic patients.

Are there vascular density gradients along myocardial laser channels?

BACKGROUND: Clinical studies suggest that transmyocardial laser revascularization may improve regional blood flow of the subendocardial layer. The vascular growth pattern of laser channels was analyzed. METHODS: Twenty pigs were randomized to undergo ligation of left marginal arteries (n = 5), to undergo transmyocardial laser revascularization of the left lateral wall (n = 5), to undergo both procedures (n = 5) or to a control group (n = 5). All the animals were sacrificed after 1 month. Computed morphometric analysis of vascular density of the involved area was expressed as number of vascular structures per square millimeter (+/-1 standard deviation). RESULTS: The vascular density of the scar tissue of the laser channel was significantly increased in comparison with myocardial infarction alone: 49.6+/-12.8/mm2 versus 25.5+/-8.6/mm2 (p < 0.0001). The vascular densities of subendocardial and subepicardial channel areas were similar: 52.9+/-16.8/mm2 versus 46.3+/-13.6/mm2 (p = 0.41). The area immediately adjacent to the channels showed a vascular density similar to that of normal tissue: 6.02+/-1.7/mm2 versus 5.2+/-1.9/mm2 (p = 0.08). In the infarction + transmyocardial laser revascularization group, the channels were indistinguishable from infarction scar. CONCLUSIONS: Scars of transmyocardial laser revascularization channels exhibit an increased vascular density in comparison with scar tissue of myocardial infarction, which does not extend into their immediate vicinity. There was no vascular density gradient along the longitudinal axis of the channels.

Incidence of stent thrombosis and adverse cardiac events 5 years after sirolimus stent implantation in clinical practice.

BACKGROUND: The long-term incidence of stent thrombosis (ST) and complications after sirolimus-eluting stents (SES) implantation is still a matter of debate. METHOD: We conducted a systematic follow-up on the day of their 5-year SES implantation anniversary, in a series of consecutive real-world patients treated with a SES. The use of SES implantation was not restricted to "on-label" indications, and target lesions included in-stent restenosis, vein graft, left main stem locations, bifurcations, and long lesions. The Academic Research Consortium criteria were used for ST classification. RESULTS: Three hundred fifty consecutive patients were treated with SES between April and December 2002 in 3 Swiss hospitals. Mean age was 63 +/- 6 years, 78% were men, 20% presented with acute coronary syndrome, and 19% were patients with diabetes. Five-year follow-up was obtained in 98% of eligible patients. Stent thrombosis had occurred in 12 patients (3.6%) [definite 6 (1.8%), probable 1 (0.3%) and possible 5 (1.5%)]. Eighty-one percent of the population was free of complications. Major adverse cardiac events occurred in 74 (21%) patients and were as follows: cardiac death 3%, noncardiac death 4%, myocardial infarction 2%, target lesion revascularization 8%, non-target lesion revascularization target vessel revascularization 3%, coronary artery bypass graft 2%. Non-TVR was performed in 8%. CONCLUSION: Our data confirm the good long-term outcome of patients treated with SES. The incidence of complications and sub acute thrombosis at 5 years in routine clinical practice reproduces the results of prospective randomized trials.

Myocardial no-reflow treatment.

No-reflow phenomenon is a consequence of percutaneous coronary intervention (PCI) which arises most of the time in the setting of myocardial infarction, but can be also the consequence of PCI in stable angina patients (rotatablator ablation technique or angioplasty in saphenous vein grafts). In this review, we summarize two ways of treating the no-reflow according to the current literature. First through the pharmacological approach where several compounds have been assessed like adenosine, nitroprusside, verapamil, nicorandil, dipyridamole, epinephrine or cyclosporine. Second through the mechanical approach where few strategies have been examined like intra-aortic balloon pumping or postconditioning. Finally, we provide an algorithm for treating a no-reflow even though no studies showed a beneficial effect in terms of clinical endpoints.

Fonction ventriculaire gauche après revascularisation pour occlusion d'une coronaire d'une durée de 1-2 heures [Left ventricular function following revascularization for occlusion of a coronary artery lasting 1 to 2 hours].

The time-lag between coronary occlusion and irreversible damage to the myocardium is ill-defined in man. In 10 patients the changes in left ventricular function have been studied after coronary occlusion during diagnostic or therapeutic cardiac catheterization of 1-2 hours' duration. Revascularization was achieved either surgically or through intracoronary streptokinase infusion. The interval between occlusion and onset of extracorporal circulation or reopening was 61 to 119 minutes. Despite enzyme elevation (CPK, CK-MB, SGOT) and appearance of Q-waves in 5 patients, no significant alteration of left ventricular function was noted on repeat cardiac catheterization 10 to 230 days after the accident. These observations, suggest that coronary occlusion of 1-2 hours' duration fails to produce significant irreversible damage to the myocardium despite electrocardiographic and enzymatic signs of myocardial infarction.

Added prognostic value of myocardial blood flow quantitation in rubidium-82 positron emission tomography imaging.

AIMS: We studied the respective added value of the quantitative myocardial blood flow (MBF) and the myocardial flow reserve (MFR) as assessed with (82)Rb positron emission tomography (PET)/CT in predicting major adverse cardiovascular events (MACEs) in patients with suspected myocardial ischaemia. METHODS AND RESULTS: Myocardial perfusion images were analysed semi-quantitatively (SDS, summed difference score) and quantitatively (MBF, MFR) in 351 patients. Follow-up was completed in 335 patients and annualized MACE (cardiac death, myocardial infarction, revascularization, or hospitalization for congestive heart failure or de novo stable angor) rates were analysed with the Kaplan-Meier method in 318 patients after excluding 17 patients with early revascularizations (<60 days). Independent predictors of MACEs were identified by multivariate analysis. During a median follow-up of 624 days (inter-quartile range 540-697), 35 MACEs occurred. An annualized MACE rate was higher in patients with ischaemia (SDS >2) (n = 105) than those without [14% (95% CI = 9.1-22%) vs. 4.5% (2.7-7.4%), P < 0.0001]. The lowest MFR tertile group (MFR <1.8) had the highest MACE rate [16% (11-25%) vs. 2.9% (1.2-7.0%) and 4.3% (2.1-9.0%), P < 0.0001]. Similarly, the lowest stress MBF tertile group (MBF <1.8 mL/min/g) had the highest MACE rate [14% (9.2-22%) vs. 7.3% (4.2-13%) and 1.8% (0.6-5.5%), P = 0.0005]. Quantitation with stress MBF or MFR had a significant independent prognostic power in addition to semi-quantitative findings. The largest added value was conferred by combining stress MBF to SDS. This holds true even for patients without ischaemia. CONCLUSION: Perfusion findings in (82)Rb PET/CT are strong MACE outcome predictors. MBF quantification has an added value allowing further risk stratification in patients with normal and abnormal perfusion images.

Quantification of the local heartwall motion by magnetic resonance myocardial tagging.

Sophisticated magnetic resonance tagging techniques provide powerful tools for the non-invasive assessment of the local heartwall motion towards a deeper fundamental understanding of local heart function. For the extraction of motion data from the time series of magnetic resonance tagged images and for the visualization of the local heartwall motion a new image analysis procedure has been developed. New parameters have been derived which allows quantification of the motion patterns and are highly sensitive to any changes in these patterns. The new procedure has been applied for heart motion analysis in healthy volunteers and in patient collectives with different heart diseases. The achieved results are summarized and discussed.