Prognostic value and clinical predictors of intramyocardial hemorrhage measured by CMR T2* sequences in STEMI.

Recent studies show that microvascular injury consists of microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH). In patients with reperfused ST-segment elevation myocardial infarction (STEMI) quantitative assessment of IMH with T2* cardiovascular magnetic resonance imaging (CMR) appears to be useful in evaluation of microvascular damage. The current study aimed to investigate feasibility of this approach and to correlate IMH with clinical and CMR parameters. A single center observational cohort study was performed in reperfused STEMI patients with CMR examination 7 days (IQR: 5 to 8 days) after percutaneous coronary intervention. Infarct size (IS) and MVO were evaluated in short-axis late gadolinium enhancement sequences and IMH with whole LV volume T2* mapping sequences. Of the 94 patients, MVO was identified in 52% of patients and the median size of MVO was 3% of LV mass (IQR: 1.5 to 5.4%). IMH was present in 28% of patients and the median size of IMH was 1.1% of LV mass (IQR: 0.5 to 2.9%). IMH extent was independently associated with anterior myocardial infarction (p = 0.022) and thrombectomy (p = 0.049). IMH was correlated with MVO (R = 0.62, p < 0.001), necrosis (R = 0.58, p < 0.001) and LVEF (R = -0.21, p = 0.04). Patients with IMH presented higher incidence of MACE events, independently of LVEF (p = 0.022). T2* mapping is a novel imaging approach that proves useful to asses IMH in the setting of reperfused STEMI. T2* IMH extent was associated with anterior infarction and thrombectomy. T2* IMH was associated with higher incidence of MACE events regardless preserved or reduced LVEF.

Pharmacological stress cardiovascular magnetic resonance: feasibility and safety in a large multicentre prospective registry.

AIMS: To assess the feasibility and incidence of immediate complications of stress cardiovascular magnetic resonance (CMR) and to determine associated factors. METHODS AND RESULTS: This was a large multicentre, prospective registry of pharmacologic stress CMR in a referral population. We used dipyridamole when no contraindication was present and dobutamine in the remaining patients. Stress CMR was performed at 1.5 T. We recorded the clinical and demographic data, quality of test, CMR findings, haemodynamic data, and complications. Stress CMR was performed in 11 984 patients (98.2% of requested), using dipyridamole in 95.4% and dobutamine in 4.6%. The study could not be performed due to claustrophobia in 0.2%. Quality was optimal in 93.4%, suboptimal in 6.2%, and poor in 0.4% of studies. Images were diagnostic in 97.6% of patients (98.7% with dipyridamole and 75.1% with dobutamine, P < 0.0001). No patient died or had acute myocardial infarction during the test. Ten patients (0.08%) had severe immediate complications, seven after dipyridamole and two after dobutamine (P = 0.062), and one anaphylactic shock post-gadolinium. The only factor significantly associated with higher incidence of serious complications was the detection of inducible ischaemia. Incidence of non-severe complications was low (1.5%), severe controlled chest pain being the most frequent. Minor symptoms occurred frequently (24.8%). Both were significantly more frequent when dobutamine was used. CONCLUSION: Performance of stress CMR is safe in a referral population. Inducible ischaemia was the only factor identified which was associated with serious complications. The incidence of non-severe complications and minor symptoms was greater with dobutamine.

Phenotypic patterns of right ventricular dysfunction: analysis by cardiac magnetic imaging.

The aim of this study was to use magnetic resonance imaging (MRI) to classify the morphological changes and remodeling of the right ventricle (RV) that occur in different clinical situations and that have an impact on RV function. Most literature has traditionally focused on the left ventricle (LV) and as a result, few studies analyze RV behavior and remodeling. The study evaluated all cardiac MRI performed at our center from 2008 to 2010. We retrospectively identified 159 patients who had some sign of right ventricular dysfunction (RVD) based on MRI findings. We classified patients according to a combination of criteria for RVD and the presence of left ventricle dysfunction (LVD). We considered RVD as any of the following abnormalities: i) depressed RV function; ii) RV dilatation; iii) RV hypertrophy. LVD was considered when there was atrial dilatation, LV hypertrophy, LV dilatation and/or depressed LV function. We obtained 6 pathophysiological patterns: RV pressure overload (1.9%), RV volume overload (15.7%), RV volume overload + LVD (32.7%), depressed RV function + LVD (42.1%), mixed RV overload + LVD (6.9%) and other (0.6%). The most frequent etiology was congenital heart disease (33.3%), followed by idiopathic dilated cardiomyopathy (18.2%), left valvular disease (17.6%), ischemic heart disease (15%), pulmonary disease (9.8%), and other (6.1%). This study helps to classify the different patterns that RV can adopt in different clinical situations and can, therefore, help us to understand the RV pathophysiology.

Etiological diagnosis of left ventricular dysfunction: computed tomography compared with coronary angiography and cardiac magnetic resonance.

INTRODUCTION AND OBJECTIVES: To evaluate the capability of multidetector computed tomography to diagnose the coronary etiology of left ventricular dysfunction compared with using invasive coronary angiography and magnetic resonance. METHODS: Forty consecutive patients with left ventricular dysfunction of uncertain etiology underwent invasive coronary angiography and contrast magnetic resonance. All patients were evaluated with multidetector computed tomography including coronary calcium presence and score, noninvasive coronary angiography, and myocardial tissue assessment. RESULTS: The sensitivity and specificity of the presence of coronary calcium to identify left ventricular dysfunction was 100% and 31%, respectively. If an Agatston calcium score of >100 is taken, specificity increases to 58% with sensitivity still 100%. Sensitivity and specificity for coronary angiography by multidetector computed tomography was 100% and 96%, respectively; for identifying necrosis in contrast acquisition it was 57% and 100%, respectively; and in late acquisition, 84% and 96%, respectively. To identify coronary ventricular dysfunction with necrosis, the sensitivity and specificity was 92% and 100%, respectively. CONCLUSIONS: Of all the diagnostic tools available in multidetector computed tomography, coronary angiography is the most accurate in determining the coronary origin of left ventricular dysfunction. A combination of coronary angiography and myocardial tissue study after contrast allows a single test to obtain similar information compared with the combination of invasive coronary angiography and contrast magnetic resonance.