La place de l’IRM cardiaque de stress dans la prise en charge de la cardiopathie ischémique

Stress magnetic cardiac resonance imaging (MRI) development is in progress. Many cardiac imaging technics already known are completed by this safe radiation free exam with a short time acquisition (30 minutes) and a good diagnostic performance in particular for patients with three vessels coronary artery diseases. Best indication concerns symptomatic patients unable to exercise with intermediate or high pretest probability. Pharmacological heart stress can be induced with vasodilatators or dobutamine to identify the presence and extent of myocardial ischemia, with high precision to guide coronary vessels revascularization. MRI gives many other interesting informations like heart anatomy, left ventricular function. Myocardial viability can be assessed with study of late gadolinium enhancement or analysis of contractile reserve with low dose of dobutamine.     

Heart failure and anaphylactic shock. A report of two cases

Anaphylactic shock can sometimes take the appearance of heart failure, in relation to an acute coronary syndrome, even with normal coronary arteries, that we illustrate by two observations. We firstly report the case of an anaphylactic shock caused by succinylcholine, after anesthesia induction for inguinal hernia surgery in a 50-year-old man with cardiovascular risks, who presented with ventricular fibrillation followed by a cardiac arrest. An acute and severe anterior coronary syndrome was suspected and treated with thrombolysis. Then the electrocardiogram normalized, as well as the left ventricular function. No significant coronary stenosis was retrospectively revealed by coronarography, and a severe coronary vasospasm induced by the anaphylactic reaction was confirmed. We also describe the case of an anaphylactoid shock caused by cisatracurium infusion, that occurred at the beginning of an adnexectomy in a 55-year-old woman without any particular history. She presented with a cardiogenic shock after intravenous administration of epinephrine. The echocardiograpghic evaluation pointed out an aspect of stress-induced cardiomyopathy, and the coronarography showed normal coronary arteries. The left ventricular dysfunction completely normalized, strongly suggesting the diagnosis of Takotsubo-like syndrome after the anaphylactic shock and its treatment. Both of these cases point out the major interest of cardiologic and allergic evaluation in case of heart failure during general anesthesia. Coronary vasospasm and stress-induced cardiomyopathy are two pathologies that may be observed during anaphylactic shock, and their diagnosis should be considered after elimination of coronary thrombosis.     

Myocarditis or subendocardial myocardial infarction: role of MRI illustrated by a case report

A 50-year-old male patient treated with mesalazine for Crohn’s disease was admitted in our unit for a chest pain, associated with nonspecific ST depression or ECG and troponine elevation. Coronarography showed minimal changes while SPECT imagery suggested a posterobasal subendocardial infarction, so that the diagnosis was unclear between ischemic disease and mesalazine-induced myocarditis. Eventually, MRI demonstrated clearly a subendocardial posterior infarction eliciting the diagnosis of mesalazine-induced myocarditis. This case report illustrates, in our opinion, that MRI is of invaluable interest in evaluating the characteristics of myocardium, and must be the cornerstone in the diagnosis of myocardial diseases.     

Why perform PCI of coronary chronic occlusion and how?

Angioplasty of coronary chronic total occlusion (CTO), defined by complete occlusion of coronary vessel with TIMI 0 flow greater than 3 months, has been avoided for many years, single vessel diseases being medically treated and multivessel diseases sent to surgeons mainly because a low success and high restenosis rates. Major improvements in devices and techniques mainly coming from Japan created a new concern about when and how to perform PCI of CTO. Clearly CTO are stable lesions but during the last years it was demonstrated that while comparing success and failure of recanalization, success improved symptoms, ischemia, left ventricular function, and even survival. Reopening CTOs can also decrease the risk of death and cardiogenic shock associated with a future acute coronary event. Selection of cases for PCI is based on well-known predictors of failure (calcifications, tortuosities, length of occluded segment and age of occlusion), on operator's experience and on a proof of viability and ischemia of the myocardium depending from occluded vessel (MRI). Many specific devices (powerful wires, microcatheters and coaxial balloons, specific guiding catheters, Tornus) and techniques (anterogrades and retrogrades through trans-septal collateral vessels) have been developed to increase success rate (70 to 90% in high volume operator hands). Outside of coronary perforations which are no more frequent in CTO lesions, some specific problems are important limitations: X-Ray exposure, contrast medium volume, and cost. With the success rate these complications are good reasons to have these procedures (or the most complex) performed by specialists.     

Dépistage de l’ischémie myocardique par l’échocardiographie de stress à la dobutamine chez le diabétique de type 2 à haut risque cardiovasculaire au Sénégal

Introduction

Diabetes is a major risk factor for coronary artery disease witch may develop insidiously. Several non-invasive methods are used to detect silent myocardial ischaemia, especially in diabetic patients at high cardiovascular risk. We project to screen, by dobutamine stress echocardiography, silent myocardial ischaemia in type 2 diabetics in Senegal.

Methodology

We randomly recruited in hospital in Senegal type 2 diabetics aged at least 40 years and a dobutamine stress echocardiography was performed in those selected according to the French Society of Cardiology and the French Language Association for the Study of Diabetes and Metabolic Diseases.

Results

Dobutamine stress echocardiography was performed in 79 diabetics at high cardiovascular risk, including 56 women. The average age was 58.8 ± 11.8 years. The exam was positive in 67.1% of cases (53/79), with a predominance of motion abnormalities in anterior territory (83%). Cardiovascular risk factors associated with positivity of test were microalbuminuria (p = 0.0001), inactivity (p = 0.0001), dyslipidemia (p = 0.0002), arterial hypertension (p = 0.001), smoking (0.003) and male sex (p = 0.004).

Conclusion

In Africa, dobutamine stress echocardiography has the advantage of its accessibility and its feasibility. Early detection of silent myocardial ischaemia in diabetics at high risk could optimize their care.     

Interest of coronary flow reserve of the LAD during dobutamine stress echocardiography

Aim of the study

To assess the value of the coronary flow reserve (CFR) in the left anterior descending artery (LAD) during dobutamine stress echocardiography in the diagnosis of significant LAD stenosis (more than 70%).

Method

Retrospective study of 81 patients with a positive stress echocardiography who underwent a coronarography.

Results

Measurement of coronary flow reserve was able in half echocardiographic exams. Medium Pic diastolic velocity was 0.33 m/s (SD 0.20), medium maximal diastolic velocity during stress was 0.62 m/s (SD 0.20), medium CFR was 2.25 (SD 0.65). In 50 patients LAD was not seen; in five of them LAD was occluded. The predictive positive value (PPV) of a low coronary flow reserve to detect LAD stenosis is 66.7% and the negative predictive value (NPV) is 65.4%. An abnormal anterior contraction during stress echo with a low reserve has a PPV of 75% for the diagnosis of significant IVA stenosis and a normal contraction during stress with normal coronary flow reserve means a NPV of 65%. We did not show a significant correlation between low coronary flow and abnormal contraction during stress echocardiography (kappa 0.51).

Conclusion

Coronary flow reserve of LAD during stress echo is feasible but does not really improve exam performance to detect significant IVA stenosis. This measurement remains to be clear in coronary patients management.     

Chronic kidney disease and myocardial infarction: epidemiological, clinical, therapeutic and prognostic characteristics (about 231 cases)

Aims of the study

To study the epidemiologic, clinical, therapeutic and prognostic characteristics of the myocardial infarction (MI) in patients with chronic kidney disease (CKD). To identify the impact of CKD in hospital, mid- and long-term survival after myocardial infarction. To determine the predictive factors of hospital and midterm MACCE in patients with CKD.

Patients and methods

The study population was 231 patients with a myocardial infarction admitted alive from January 2005 to December 2006. The population was divided into two groups. Group 1: glomerular filtration rate (GFR) ≥60 ml/min: 112 patients; group 2: GFR < 60 ml/min: 119 patients.

Results

Patients with CKD had more history of stroke and arterial hypertension. They had received less medical therapies and urgent reperfusion. In multivariate analysis, CKD was a predictive factor of hospital (P = 0.016), at 6 months (P = 0.003), at 1 year (P = 0.004) and at 2 years MACCE (P = 0,015). The predictive factors of hospital MACCE in group 2 were: use of vasopressors (P = 0.001) and primary angioplasty (P = 0.043). In patients with CKD, only surgical coronary revascularization was MACCE predictive factor (P = 0.03).

Conclusion

Baseline renal function is a powerful predictor of short- and long-term events after myocardial infarction. Our results confirm the need to include the renal function in the evaluation of the level of risk among patients admitted with acute myocardial infarction.     

Convulsives crisis revealing left-ventricular non-compaction with apical myocardial infarction

Left-ventricular non-compaction is a rare congenital disorder and its association with myocardial infarction is rarely described in literature. We report the case of a patient in whom the diagnosis was established after multiple convulsive crisis. The resemblance of certain consequences of these two pathologies reports the difficulty of the diagnosis of imputability and all the specificity of this observation.     

Bleeding risk in ST-segment elevation myocardial infarction

Coronary reperfusion of acute coronary syndromes with ST segment elevation requires medical treatment involving potential thrombolysis as well as very potent anticoagulant and antiplatelet medications. In such a therapeutic setting, the risk of bleeding complications may be high and should be taken into account accordingly. An accurate definition of these bleeding complications is crucial in order to compare all currently available treatments and strategies appropriately. The heterogeneous definitions often published in the literature make any valid interpretations of the results very difficult. These bleeding complications, which affect negatively the outcome of patients undergoing treatment should be adequately anticipated in our treatment strategies. An exhaustive knowledge of the bleeding risk factors is necessary in order to adjust the treatment modalities. The occurrence of bleeding may be related to the vascular approach used for cardiac catheterization. In this respect, the superiority of the radial approach has been widely demonstrated. In addition, certain instances of bleeding are not related to the vascular approach, such as digestive and neurological bleeding which can have very severe consequences. Consequently, it is necessary to adapt treatments with heterogeneous potential for bleeding to individual bleeding risk factors, which may be quantified by scores measuring the bleeding risk. Finally, treatment combinations must often be carefully tailored to the characteristics of each individual patient.     

Diagnosis of cardiac amyloidosis using magnetic resonance imaging: a new reliable, non-invasive technique to be validated

Introduction

Amyloidosis is characterised by extracellular tissue deposition of insoluble fibrillar protein in various organs. Cardiac involvement is associated with the worse prognosis and the main cause of death. It needs a prompt diagnosis, which could be sometimes difficult to obtain. Endomyocardial biopsy remains the gold standard diagnostic technique, but recent studies on cardiac magnetic resonance imaging (MRI) indicate that this imaging procedure may be useful to the diagnosis of amyloidosis.

Case reports

We report three patients with systemic amyloidosis who underwent cardiac MRI for the diagnosis or the follow-up of their disease. In addition to poorly specific signs of restrictive cardiomyopathy, cardiac MRI showed, after gadolinium enhancement that was considered characteristic of amyloidosis.

Conclusion

Cardiac MRI is a useful diagnostic tool in cardiac amyloidosis, as it was shown in recent studies. Compared to endomyocardial biopsy it is a non-invasive technique that is now more readily accessible and that seems to have an acceptable specificity.     

Outcome in AN adult patients: a 13-year follow-up in 484 patients

Background

To study the long-term prognosis of anorexia nervosa (AN), 484 adult AN patients were followed on a mean duration of 13 years.

Results

The mortality rate was 1.2%. Eight factors were linked to the lack of recovery at 2 years: low BMI at discharge, low energy and fat intakes, high drive for excessive exercising, high score for perfectionism, for interpersonal distrust and for anxiety, use of tube-feeding and adhesion to treatment (P < 0.02). Four factors explained the risk of the binge/purging form at 2 years: having had binge-eating disorder and overweight before AN, having had purging episodes within the first 2 years of AN; having had very high energy intakes through meals and being not treated by tube-feeding. During the 13-year follow-up, very few binge/purging patients turned out to have the restrictive form. Two main factors explained 67% of the variance of menses recovery: having a BMI > 18.5 kg/m²; and having no physical hyperactivity. The recovery rate increased with the elapsing of relapse-free time (P = 0.02). After a 13.5-year follow-up, 292 out of the 484 patients were recovered (60.3%), 25.8% had a relatively good outcome, 6.4% a bad outcome and 6.4% a severe outcome. Very few factors were identified as predictors of a good outcome (binge-eating/purging subtype, personality disorder).     

Voie radiale et insuffisance rénale

Patients with chronic kidney disease have a high cardiovascular risk and mortality. This problem is growing because of the aging of the population and prevalence of diabetes. Transradial approach is traditionally prohibited due to the injury that catheterization induces on this artery that could possibly influence its suitability as an arteriovenous fistula. Paradoxically, the increased risk of major vascular complications with femoral access leads to transgress this rule. Indeed, transradial approach by reducing dramatically the rate of vascular bleeding complications leads to a significant reduction of adverse events and mortality, especially in the high cardiovascular risk sub-group. In patients with chronic kidney disease, choice of vascular access site should compare the potentially fatal risk of vascular complications with the one of traumatizing the artery needed to create a distal hemodialysis access site. Thus, chronic renal insufficiency even on hemodialysis should not be an absolute contraindication to radial approach, which could be used individually by a skilled team and in a mini-invasive spirit. A large randomised study comparing radial and femoral access in this population is needed.     

Coronary angioplasty in women

The cardiovascular risk is the main cause of mortality and is increasing with age in women. In old women, this risk is similar to men. Many cardiovascular treatments are used in women without a clear demonstration of their efficiency in this population. It is only extrapolations of studies enrolling a large majority of males (more than 85%). It is very important to improve our therapeutic strategies in women, for all clinical presentations (stable angina or acute coronary syndromes), to perform dedicated studies. In fact, the rate of success of coronary angioplasty in women is similar to men but the prognosis is worse. This is partly explained by a waiting-game in the strategy and some anatomic differences such as smaller vessels diameters and also a high rate of vascular complications. To decrease this risk of vascular complications, the use of transradial seems to be a good solution. In another hand, in women, the use of drug eluting stent (DES) gives good results comparable to men. But no study has been dedicated to this group of patients.