Stéphane Delépine

Coronary Blood Flow Assessment After Successful Angioplasty for Acute Myocardial Infarction Predicts the Risk of Long-Term Cardiac Events

Background—Analysis of coronary flow velocity (CFV) in the recanalized infarct-related coronary artery (IRA) with a Doppler guidewire is useful for predicting recovery of regional left ventricular function, in-hospital complications, and survival. We postulated that the CFV pattern after IRA reperfusion for acute myocardial infarction (AMI) would predict long-term adverse cardiac events. Methods and Results—Sixty-eight consecutive patients with a first AMI underwent CFV measurement with a Doppler guidewire after successful reopening of the IRA by coronary angioplasty. At the end of follow-up, 3.8±1.7 years after AMI, 44 of the 65 surviving patients (67.7%) were free of long-term cardiac events. Univariate analysis showed that the following factors were predictive of an end point combining cardiac death, recurrent MI, and congestive heart failure: hypertension, age ≥65 years, time from onset of chest pain to PTCA ≥6 hours, peak creatine kinase >4000 IU/L, ejection fraction ≤50%, proximal left anterior descending artery occlusion, resting average peak velocity ≤10 cm/s, average systolic peak velocity ≤5 cm/s, a rapid diastolic deceleration time (≤600 ms), and early retrograde systolic flow. In the final multivariate model, only age ≥65 years (OR, 3.6; 95% CI, 1.1 to 11.8; P=0.03), time to PTCA ≥6 hours (OR, 2.9; 95% CI, 1.0 to 8.3; P=0.04), and a rapid diastolic deceleration time (OR, 5.4; 95% CI, 1.5 to 19.3; P=0.01) were independent predictors. Conclusions—The CFV pattern appears to be an accurate predictor of long-term cardiac events in patients having undergone successful reopening of the IRA after AMI, identifying a subset of at-risk patients.

Single high-dose erythropoietin administration immediately after reperfusion in patients with ST-segment elevation myocardial infarction: results of the erythropoietin in myocardial infarction trial.

BACKGROUND Preclinical studies and pilot clinical trials have shown that high-dose erythropoietin (EPO) reduces infarct size in acute myocardial infarction. We investigated whether a single high-dose of EPO administered immediately after reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) would limit infarct size. METHODS A total of 110 patients undergoing successful primary coronary intervention for a first STEMI was randomized to receive standard care either alone (n = 57) or combined with intravenous administration of 1,000 U/kg of epoetin β immediately after reperfusion (n = 53). The primary end point was infarct size assessed by gadolinium-enhanced cardiac magnetic resonance after 3 months. Secondary end points included left ventricular (LV) volume and function at 5-day and 3-month follow-up, incidence of microvascular obstruction (MVO), and safety. RESULTS Erythropoietin significantly decreased the incidence of MVO (43.4% vs 65.3% in the control group, P = .03) and reduced LV volume, mass, and function impairment at 5-day follow-up (all P < .05). After 3 months, median infarct size (interquartile range) was 17.5 g (7.6-26.1 g) in the EPO group and 16.0 g (9.4-28.2 g) in the control group (P = .64); LV mass, volume, and function were not significantly different between the 2 groups. The same number of major adverse cardiac events occurred in both groups. CONCLUSIONS Single high-dose EPO administered immediately after successful reperfusion in patients with STEMI did not reduce infarct size at 3-month follow-up. However, this regimen decreased the incidence of MVO and was associated with transient favorable effects on LV volume and function.

Regional assessment of wall curvature and wall stress in left ventricle with magnetic resonance imaging

Left ventricular functional abnormalities are associated with regional increases of wall stress and modifications of wall curvature. This study describes the integration of the short-axis and long-axis wall curvatures for determining peak systolic wall stress. Quantification was realized with cine magnetic resonance imaging (MRI) from the location of the endocardial and epicardial borders of the left ventricle on pairs of consecutive short-axis sections. Fifteen normal volunteers were subjected to cine MRI, and different methods of calculating peak systolic wall stress were compared. A short-axis analysis showed a 55 +/- 13% increase of the circumferential mean of the peak systolic wall stress between apical and basal sections. Regarding the curvature, no significant increase of wall stress was observed except on the septal wall (31 +/- 18%). Short-axis studies proved to be insufficient for determining the regional variations of left ventricular wall stress and for providing normal reference values for the location of abnormal regions in patients.

GLOBAL LEFT VENTRICULAR CARDIAC FUNCTION : COMPARISON BETWEEN MAGNETIC RESONANCE IMAGING, RADIONUCLIDE ANGIOGRAPHY, AND CONTRAST ANGIOGRAPHY

RATIONALE AND OBJECTIVES Cardiac magnetic resonance imaging (MRI) has been shown to be a robust and noninvasive method to assess left ventricular (LV) cardiac function. This study sought to assess volumes and mass calculated with MRI using fast techniques for acquisition and postprocessing, and to compare results in terms of cost-effectiveness with those of radionuclide angiography (RNA) or contrast angiography (CA). METHODS Thirty-five patients and 15 healthy volunteers were studied. All patients underwent an MRI examination during the same period that they underwent ventriculography (26 patients) or radiography (25 patients). From 7 to 11 short-axis slices were acquired with a breath-hold fast-gradient echo-segmented sequence from apex to base. Contours were drawn with an automated border detection software. RESULTS Ejection fraction (EF) correlated well between modalities (r = 0.77, P<0.001, for MRI and RNA; r = 0.72, P< 0.001, for MRI and CA). CONCLUSIONS Cardiac MRI is a fast and accurate technique for estimation of LV volumes, EF, and mass.

CMR assessment after a transapical-transcatheter aortic valve implantation

AIMS To describe the time course of myocardial scarring after transapical-transcatheter aortic valve implantation (TA-TAVI) with the Edwards SAPIEN XT™ and the Edwards SAPIEN™ prosthesis in a 3-month follow-up study using cardiac magnetic resonance imaging (CMR). METHODS In 20 TA-TAVI patients, CMR was performed at discharge and 3 months (3M). Cine-MRI was used for left ventricular (LV) functional assessment, and late gadolinium enhancement (LGE) imaging was employed for detecting the presence of myocardial scarring. Special attention was given to any artifacts caused by the prosthesis, which were consequently defined using a three-grade artifact scale. RESULTS We systematically reported the presence of small LGE hyperintensity relating to the apical segment, with no variation found between discharge and 3M (2.8±1.6g vs. 2.35±1.1g). LV ejection fraction, end-diastolic, and end-systolic volumes did not significantly vary. A small area of apical akinesia was observed, with no improvement at follow-up. Whereas the Edwards SAPIEN XT™ prosthesis and the Edwards SAPIEN™ prosthesis are both constituted by metallic stenting structure, the Edwards SAPIEN™ was responsible for a larger signal void, thus potentially limiting the diagnostic performance of CMR. CONCLUSIONS CMR may be performed safely in the context of TA-TAVI. The presence of a very small apical infarction correlating with focal akinesia was observed. As expected, the Edwards SAPIEN XT™ prosthesis was shown to be particularly suitable for CMR assessment.

Three-dimensional MRI assessment of regional wall stress after acute myocardial infarction predicts postdischarge cardiac events

To determine the prognostic significance of systolic wall stress (SWS) after reperfused acute myocardial infarction (AMI) using MRI.

0179: Transcatheter valve-in-valve implantation in patients with failed aortic bioprosthesis: immediate and medium-term outcomes of 15 procedures

Background TAVI offers an attractive option for patients with failed bioprosthesis and high operative risk (valve-in-valve concept). Purpose The objective of this study was to analyze outcomes of patients with failed aortic bioprosthesis undergoing transcatheter aortic valve-in-valve implantation. Methods From January 2012 to January 2015, 15 patients with degenerated aortic valve bioprosthesis underwent transcatheter aortic valve-in-valve implantation in our institution. Mean patient age was 82±6 years. Mean logistic Euroscore was 36±16% and mean STS score was 16±14%. The mean follow-up was 260±316 days. Results The failing bioprosthesis were Cryolife O’brien in 5 patients, Carpentier Edwards in 5 patients, Medtronic mosaic in 4 patients and Mitroflow in 1 patient. Bioprosthesis mode of failure was stenosis (n=6), regurgitation (n=5), or combined stenosis and regurgitation (n=4). The mean degenerative time was 11.15±6.1 years. Implanted devices included Medtronic CoreValve (n=6) and Edwards SAPIEN (n=9). Successful implantation of a transcatheter aortic valve-in-valve with the patient leaving the catheterization laboratory alive was achieved in all patients. Adverse procedural outcomes included initial device malposition in 3 cases requiring a second valve, retroperitoneal hematoma in 1 patient, permanent pacemaker in 1 patient, Stroke in 1 patient and acute renal failure in 1 patient. The mean transvalvular gradient passed from 48.7±17.63 to 18.32±9.3mmHg in stenotic degenerated bioprosthesis. No significant aortic regurgitation was observed post-implantation. During hospitalization, 1 patient developed myocardial infarction. The medium inhospital stay was 13.4±7.7 days. During later follow-up, there was no death, no myocardial infarction and no stroke or TIA. 2 patients were hospitalized for heart failure. Conclusion Transcatheter aortic valve-in-valve implantation seems to be feasible and safe in both stenotic and regurgitant degenerative bioprosthesis.