Fabian Chaustre

Prognostic value of a comprehensive cardiac magnetic resonance assessment soon after a first ST-segment elevation myocardial infarction.

OBJECTIVES To evaluate the prognostic value of a comprehensive cardiac magnetic resonance (CMR) assessment soon after a first ST-segment elevation myocardial infarction (STEMI). BACKGROUND CMR allows for a simultaneous assessment of wall motion abnormalities (WMA), WMA with low-dose dobutamine (WMA-dobutamine), microvascular obstruction, and transmural necrosis. This approach has been proven to be useful to predict late systolic recovery soon after STEMI. Its prognostic value and the relative prognostic weight of these indexes are not well-defined. METHODS We studied 214 consecutive patients with a first STEMI treated with thrombolytic therapy or primary angioplasty discharged from hospital. In the first week (7 +/- 1 day after infarction), with CMR we determined the extent (number of segments) of WMA, WMA-dobutamine, microvascular obstruction, and transmural necrosis. RESULTS During a median follow-up of 553 days, 21 major adverse cardiac events (MACE) including 4 cardiac deaths, 6 nonfatal myocardial infarctions, and 11 readmissions for heart failure were documented. The MACE was associated with a larger extent of WMA (8 +/- 4 segments vs. 5 +/- 3 segments, p < 0.001), WMA-dobutamine (6 +/- 4 segments vs. 4 +/- 3 segments, p = 0.004), microvascular obstruction (3 +/- 3 segments vs. 1 +/- 2 segments p <0.001), and transmural necrosis (7 +/- 3 segments vs. 3 +/- 3 segments, p < 0.001). In a complete multivariate analysis that included baseline characteristics, electrocardiogram, biomarkers, angiography, ejection fraction, left ventricular volumes, and all CMR indexes, WMA/segment (hazard ratio: 1.29 [95% confidence interval: 1.11 to 1.49], p = 0.001) and the extent of transmural necrosis/segment (hazard ratio: 1.30 [95% confidence interval: 1.12 to 1.51], p < 0.001) were the only independent prognostic variables. CONCLUSIONS A comprehensive CMR assessment is useful for stratifying risk soon after STEMI, but only the extent of systolic dysfunction and of transmural necrosis provide independent prognostic information.

Cardiovascular magnetic resonance-derived intramyocardial hemorrhage after STEMI: Influence on long-term prognosis, adverse left ventricular remodeling and relationship with microvascular obstruction

BACKGROUND T2 weighted cardiovascular magnetic resonance (CMR) can detect intramyocardial hemorrhage (IMH) after ST-elevation myocardial infarction (STEMI). The long-term prognostic value of IMH beyond a comprehensive CMR assessment with late enhancement (LE) imaging including microvascular obstruction (MVO) is unclear. The value of CMR-derived IMH for predicting major adverse cardiac events (MACE) and adverse cardiac remodeling after STEMI and its relationship with MVO was analyzed. METHODS CMR including LE and T2 sequences was performed in 304 patients 1 week after STEMI. Adverse remodeling was defined as dilated left ventricular end-systolic volume indexes (dLVESV) at 6 months CMR. RESULTS During a median follow-up of 140 weeks, 47 MACE (10 cardiac deaths, 16 myocardial infarctions, 21 heart failure episodes) occurred. Predictors of MACE were ejection fraction (HR .95 95% CI [.93-.97], p=.001, per %) and IMH (HR 1.17 95% CI [1.03-1.33], p=.01, per segment). The extent of MVO and IMH significantly correlated (r=.951, p<.0001). dLVESV was present in 40% of patients. CMR predictors of dLVESV were: LVESV (OR 1.11 95% CI [1.07-1.15], p<.0001, per ml/m(2)), infarct size (OR 1.05 95% CI [1.01-1.09], p=.02, per %) and IMH (OR 1.54 95% CI [1.15-2.07], p=.004, per segment). Addition of T2 information did not improve the LE and cine CMR-model for predicting MACE (.744 95% CI [.659-.829] vs. .734 95% CI [.650-.818], p=.6) or dLVESV (.914 95% CI [.875-.952] vs. .913 95% CI [.875-.952], p=.9). CONCLUSIONS IMH after STEMI predicts MACE and adverse remodeling. Nevertheless, with a strong interrelation with MVO, the addition of T2 imaging does not improve the predictive value of LE-CMR.

Contractile Reserve and Extent of Transmural Necrosis in the Setting of Myocardial Stunning: Comparison at Cardiac MR Imaging

PURPOSE To perform a comparison of cardiac magnetic resonance (MR) imaging-derived ejection fraction (EF) during low-dose dobutamine infusion (EF(D)) with the extent of segments with transmural necrosis in more than 50% of their wall thickness (ETN) for the prediction of major adverse cardiac events (MACEs) and late systolic recovery soon after a first ST-segment elevation myocardial infarction (STEMI). MATERIALS AND METHODS Institutional ethics committee approval and written informed consent were obtained. One hundred nineteen consecutive patients with a first STEMI, a depressed left ventricular EF, and an open infarct-related artery underwent MR imaging at 1 week after infarction. EF(D) and ETN (by using a 17-segment model) were determined, and the prediction of MACEs and systolic recovery at follow-up was assessed by using area under the receiver operating characteristic curve (AUC) and multivariable regression analysis. RESULTS During follow-up (median, 613 days; range, 312-1243 days), 18 MACEs (five cardiac deaths, six myocardial infarctions, seven readmissions for heart failure) occurred. MACEs were associated with a lower EF(D) (43% +/- 12 [standard deviation] vs 49% +/- 10, P = .02) and a larger ETN (seven segments +/- three vs four segments +/- three, P < .001). Patients with systolic recovery (increase in EF of >5% at follow-up compared with baseline EF, n = 44) displayed a higher EF(D) (51% +/- 10 vs 47% +/- 9, P = .04) and a smaller ETN (three segments +/- two vs five segments +/- three, P = .002) at 1 week. ETN and EF(D) both related to MACEs (AUC: 0.78 vs 0.67, respectively, P = .1) and systolic recovery (AUC: 0.68 vs 0.62, respectively, P = .3). According to multivariable analysis, ETN was the only MR variable associated with time to MACEs (hazard ratio, 1.38; 95% confidence interval: 1.19, 1.60; P < .001) and systolic recovery (odds ratio, 0.76; 95% confidence interval: 0.64, 0.92; P = .004) independent of baseline characteristics. CONCLUSION ETN is as useful as EF(D) for the prediction of MACEs and systolic recovery soon after STEMI.

Right ventricular involvement in anterior myocardial infarction: a translational approach

AIMS The aim of the present study was to evaluate the involvement of the right ventricle (RV) in reperfused anterior ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS Left anterior descending (LAD)-perfused area (using thioflavin-S staining after selective infusion in proximal LAD artery, %), infarct size (using triphenyltetrazolium chloride staining, %), and salvaged myocardium (% of LAD-perfused area) in the right and left ventricle (LV) were quantified in a 90-min LAD occlusion 3-day reperfusion model in swine (n = 8). Additionally, we studied, using cardiovascular magnetic resonance, 20 patients with a first STEMI due to proximal LAD occlusion treated with primary angioplasty. Area at risk (T2-weighted sequence, %), infarct size (late enhancement imaging, %), and salvaged myocardium (% of area at risk) in the right and LV were quantified. In swine, a large LAD-perfused area was detected both in the right and LV (30 +/- 5 vs. 62 +/- 15%, P< 0.001) but more salvaged myocardium (94 +/- 6 vs. 73 +/- 11%, P< 0.001) resulted in a smaller right ventricular infarct size (2 +/- 1 vs. 16 +/- 5%, P< 0.001). Similarly, in patients a large area at risk was detected both in the right and LV (34 +/- 13 vs. 43 +/- 12%, P = 0.02). More salvaged myocardium (94 +/- 10 vs. 33 +/- 26%, P < 0.001) resulted in a smaller infarct size (2 +/- 3 vs. 30 +/- 16%, P< 0.001) in the RV. CONCLUSION In reperfused extensive anterior STEMI, a large area of the RV is at risk but the resultant infarct size is small.

Prognostic implications of dipyridamole cardiac MR imaging: a prospective multicenter registry.

PURPOSE To evaluate dipyridamole cardiac magnetic resonance (MR) imaging in the prediction of major events (MEs) in patients with ischemic chest pain in a large multicenter registry. MATERIALS AND METHODS Institutional ethics committee approval and written informed consent were obtained. A total of 1722 patients who were undergoing cardiac MR imaging for chest pain were included. Wall motion abnormalities (WMAs) at rest, hyperemia perfusion defect (PD), late gadolinium enhancement (LGE), and inducible WMA were analyzed (abnormal if more than one abnormal segment was seen) with the 17-segment model. A cardiac MR categorization was created: category 1, no PD, LGE, or inducible WMA; category 2, PD without LGE and inducible WMA; category 3, LGE without inducible WMA; and category 4, inducible WMA. The association with ME was analyzed by using Cox proportional hazard regression multivariate models. RESULTS During a median follow-up period of 308 days, 61 MEs (4%) occurred (36 cardiac deaths, 25 nonfatal myocardial infarctions). MEs were associated with a greater extent of WMA, PD, LGE, and inducible WMA (P ≤ .001 for all analyses). In multivariable analyses, PD (P = .002) and inducible WMA (P = .0001) were the only cardiac MR predictors. ME rate in categories 1, 2, 3, and 4 was 2% (14 of 901 patients), 3% (six of 219 patients), 4% (15 of 409 patients), and 14% (26 of 193 patients), respectively (category 4 vs category 1, adjusted P < .001). Cardiac MR-directed revascularization was performed in 242 patients (14%) and reduced the risk of ME in only category 4 (7% [six of 92 patients] vs 26% [26 of 101 patients], P = .0004). CONCLUSION Dipyridamole cardiac MR imaging can be used to predict MEs in patients with ischemic chest pain. Patients with inducible WMA are at the highest risk for MEs and benefit the most from revascularization.

Value of Early Cardiovascular Magnetic Resonance for the Prediction of Adverse Arrhythmic Cardiac Events After a First Noncomplicated ST-Segment-Elevation Myocardial Infarction

Background— Infarct size (IS) determined by cardiac magnetic resonance (CMR) has proven an additional value, on top of left ventricular ejection fraction (LVEF), in prediction of adverse arrhythmic cardiac events (AACEs) in chronic ischemic heart disease. Its value soon after an acute ST-segment–elevation myocardial infarction remains unknown. Our aim was to determine whether early CMR can improve AACE risk prediction after acute ST-segment–elevation myocardial infarction. Methods and Results— Patients admitted for a first noncomplicated ST-segment–elevation myocardial infarction were prospectively followed up. A total of 440 patients were included. All of them underwent CMR 1 week after admission. CMR-derived LVEF and IS (grams per meter squared) were quantified. AACEs included postdischarge sudden death, sustained ventricular tachycardia, and ventricular fibrillation either documented on ECG or recorded via an implantable cardioverter-defibrillator. Within a median follow-up of 2 years, 11 AACEs (2.5%) were detected: 5 sudden deaths (1.1%) and 6 spontaneous ventricular tachycardia/ventricular fibrillation. In the whole group, AACEs associated with more depressed LVEF (adjusted hazard ratio [95% confidence interval], 0.90 [0.83–0.97]; P<0.01) and larger IS (adjusted hazard ratio [95% confidence interval], 1.06 [1.01–1.12]; P=0.01). According to the corresponding area under the receiver operating characteristic curve, LVEF ⩽36% and IS ≥23.5 g/m2 best predicted AACEs. The vast majority of AACEs (10/11) occurred in patients with simultaneous depressed LVEF ⩽36% and IS ≥23.5 g/m2 (n=39). Conclusions— In the era of reperfusion therapies, occurrence of AACEs in patients with an in-hospital noncomplicated first ST-segment–elevation myocardial infarction is low. In this setting, assessment of an early CMR-derived IS could be useful for further optimization of AACE risk prediction.

Resultados de la estrategia farmacoinvasiva y de la angioplastia primaria en la reperfusión del infarto con elevación del segmento ST. Estudio con resonancia magnética cardiaca en la primera semana y en el sexto mes

INTRODUCTION AND OBJECTIVES Pharmacoinvasive strategy represents an attractive alternative to primary angioplasty. Using cardiovascular magnetic resonance imaging we compared the left ventricular outcome of the pharmacoinvasive strategy and primary angioplasty for the reperfusion of ST-segment elevation myocardial infarction. METHODS Cardiovascular magnetic resonance was performed 1 week and 6 months after infarction in two consecutive cohorts of patients included in a prospective university hospital ST-segment elevation myocardial infarction registry. During the period 2004-2006, 151 patients were treated with pharmacoinvasive strategy (thrombolysis followed by routine non-immediate angioplasty). During the period 2007-2008, 93 patients were treated with primary angioplasty. A propensity score matched population was also evaluated. RESULTS At 1-week cardiovascular magnetic resonance, pharmacoinvasive strategy and primary angioplasty patients showed a similar extent of area at risk (29±15 vs. 29±17%, P=.9). Non-significant differences were detected by cardiovascular magnetic resonance at 1 week and at 6 months in infarct size, salvaged myocardium, microvascular obstruction, ejection fraction, end-diastolic volume index and end-systolic volume index (P>.2 in all cases). The same trend was observed in 1-to-1 propensity score matched patients. The rate of major adverse cardiac events (death and/or re-infarction) at 1 year was 6% in pharmacoinvasive strategy and 7% in primary angioplasty patients (P=.7). CONCLUSIONS A pharmacoinvasive strategy including thrombolysis and routine non-immediate angioplasty represents a widely available and logistically attractive approach that yields identical short-term and long-term cardiovascular magnetic resonance-derived left ventricular outcome compared to primary angioplasty.

Effect of ischemic postconditioning on microvascular obstruction in reperfused myocardial infarction. Results of a randomized study in patients and of an experimental model in swine.

BACKGROUND Ischemic postconditioning (PCON) appears as a potentially beneficial tool in ST-segment elevation myocardial infarction (STEMI). We evaluated the effect of PCON on microvascular obstruction (MVO) in STEMI patients and in an experimental swine model. METHODS A prospective randomized study in patients and an experimental study in swine were carried out in two university hospitals in Spain. 101 consecutive STEMI patients were randomized to undergo primary angioplasty followed by PCON or primary angioplasty alone (non-PCON). Using late gadolinium enhancement cardiovascular magnetic resonance, infarct size and MVO were quantified (% of left ventricular mass). In swine, using an angioplasty balloon-induced anterior STEMI model, MVO was defined as the % of area at risk without thioflavin-S staining. RESULTS In patients, PCON (n=49) in comparison with non-PCON (n=52) did not significantly reduce MVO (0 [0-1.02]% vs. 0 [0-2.1]% p=0.2) or IS (18 ± 13% vs. 21 ± 14%, p=0.2). MVO (>1 segment in the 17-segment model) occurred in 12/49 (25%) PCON and in 18/52 (35%) non-PCON patients, p=0.3. No significant differences were observed between PCON and non-PCON patients in left ventricular volumes, ejection fraction or the extent of hemorrhage. In the swine model, MVO occurred in 4/6 (67%) PCON and in 4/6 (67%) non-PCON pigs, p=0.9. The extent of MVO (10 ± 7% vs. 10 ± 8%, p=0.9) and infarct size (23 ± 14% vs. 24 ± 10%, p=0.8) was not reduced in PCON compared with non-PCON pigs. CONCLUSIONS Ischemic postconditioning does not significantly reduce microvascular obstruction in ST-segment elevation myocardial infarction. Clinical Trial Registration http://www.clinicaltrials.gov. Unique identifier: NCT01898546.

Cardiac magnetic resonance evaluation of edema after ST-elevation acute myocardial infarction.

INTRODUCTION AND OBJECTIVES The aims of the study were to characterize myocardial edema after ST-elevation acute myocardial infarction using cardiac magnetic resonance imaging and to investigate its impact on ventricular function and its subsequent evolution. METHODS In total, 134 patients admitted to hospital for a first ST-elevation myocardial infarction who had a patent infarct-related artery underwent cardiac magnetic resonance imaging. Cine images (at rest and with low-dose dobutamine) and edema, perfusion and viability images were acquired. Imaging was repeated after 6 months. RESULTS In the first week after infarction, edema was detected in at least one segment in 96.6% of patients (4+/-2.1 segments per patient). Extensive edema (> or = 4 segments) was associated with large ventricular end-diastolic and end-systolic volumes (P< .0001), a small left ventricular ejection fraction at rest (P=.001) and with low-dose dobutamine (P=.006), a large number of segments showing hypoperfusion (P=.001) or microvascular obstruction (P=.009), a more extensive infarct (P=.017) and greater transmural extent of the infarct (P=.003). The association between the presence and extent of edema during the first week and functional, perfusion and viability variables was still observable after 6 months. No patient exhibited edema at 6 months. CONCLUSIONS Cardiac magnetic resonance imaging was useful for characterizing the myocardial edema that occurred after ST-elevation acute myocardial infarction. Extensive edema was associated with poor left ventricular characteristics. Edema was a transitory phenomenon that vanished within 6 months.

La suma de la elevación del segmento ST predice mejor la obstrucción microvascular en pacientes tratados con éxito con una intervención coronaria percutánea primaria. Un estudio de resonancia magnética cardiovascular

Introduccion y objetivos La utilidad de la resolucion del segmento ST (RST) para la prediccion de la reperfusion epicardica esta bien establecida. La asociacion de los cambios del segmento ST con la obstruccion microvascular (OMV) observada en la resonancia magnetica cardiovascular (RMC) tras una intervencion coronaria percutanea primaria (ICPp) en el infarto de miocardio con elevacion del ST (IMEST) no se ha aclarado todavia. Metodos Estudiamos a 85 pacientes consecutivos ingresados por un primer IMEST y tratados con una ICPp que tenian una arteria relacionada con el infarto permeable. Se registro un ECG al ingreso, tras 90 min y tras 6, 24, 48 y 96 h de la ICPp. Se calculo la RST y la suma de la elevacion del ST (sumEST) en todas las derivaciones. Resultados La RMC revelo una OMV en 37 pacientes. En los infartos con OMV, el valor de la sumEST antes y despues de la revascularizacion fue mayor que en los infartos sin OMV (p ≤ 0,001 en todos los casos). En cambio, no hubo diferencias significativas en la cantidad de RST entre los infartos con y sin OMV a los 90 min de la revascularizacion (p = 0,1), sino solo a partir de las 6 h (p 3 mm a los 90 min de la ICPp, pero no una RST ≥ 70%, predijo de manera independiente la OMV observada en la RMC ( odds ratio = 3,1; intervalo de confianza del 95%, 1,2-8,4; p = 0,02). Conclusiones La OMV se asocio a un valor significativamente superior de la sumEST en todos los momentos de valoracion tras la revascularizacion. La diferencia en la cantidad de RST entre los infartos con OMV y sin OMV solo fue significativa a partir de las 6 h tras la revascularizacion. La OMV se predijo mejor con una sumEST > 3 mm a los 90 min de la ICPp.