Dominik Buckert

Intermediate-term prognostic value of reversible perfusion deficit diagnosed by adenosine CMR: a prospective follow-up study in a consecutive patient population.

OBJECTIVES The aim of this study was to assess the hypothesis that cardiac magnetic resonance (CMR) myocardial perfusion imaging can provide incremental prognostic value over other risk factors regarding the prediction of major cardiovascular events in a large, consecutive, and thereby unselected population of patients presenting with stable angina pectoris. BACKGROUND Recently, it has been shown that CMR provides good short-term prognosis in patients with stable coronary heart disease. Reversible myocardial ischemia can be assessed using a combination of perfusion and late gadolinium enhancement imaging. Data concerning intermediate-term prognostic information, especially on major clinical endpoints such as cardiac death or myocardial infarction, are limited. METHODS From 2003 to 2007, consecutive patients with stable angina pectoris who underwent adenosine perfusion CMR were enrolled unless they met the predefined exclusion criteria. Myocardial perfusion imaging by adenosine stress and late gadolinium enhancement was assessed using a 1.5-T whole-body CMR scanner. Follow-up information concerning the combined endpoint of cardiac death, nonfatal myocardial infarction, and stroke was obtained from patients, general practitioners, or treating hospitals, respectively. RESULTS In our study, 1,229 consecutive patients were enrolled. The mean follow-up period was 4.2 ± 2.1 years. During this time, 88 primary endpoints occurred. In patients with reversible perfusion deficits, significantly more cardiac deaths (p < 0.0001) and nonfatal myocardial infarctions (p = 0.001) were observed than in the control group. On multivariate analysis, reversible perfusion deficit was the strongest independent predictor for an event, with a 3-fold increased risk. Moreover, the absence of a perfusion deficit was shown to exhibit high negative predictive value. CONCLUSIONS Adenosine perfusion CMR provides excellent risk stratification and intermediate-term prognostic value in patients with stable coronary artery disease. The presence of a myocardial perfusion deficit is an incremental prognostic risk factor over other risk factors.

Cardiac magnetic resonance imaging derived quantification of myocardial ischemia and scar improves risk stratification and patient management in stable coronary artery disease

BACKGROUND Quantification of myocardial ischemia and necrosis might ameliorate prognostic models and lead to improved patient management. However, no standardized consensus on how to assess and quantify these parameters has been established. The aim of this study was to quantify these variables by cardiac magnetic resonance imaging (CMR) and to establish possible incremental implications in cardiovascular risk prediction. METHODS This study is a retrospective analysis of patients with known or suspected coronary artery disease (CAD) referred for adenosine perfusion CMR was performed. Myocardial ischemia and necrosis were assessed and quantified using an algorithm based on standard first-pass perfusion imaging and late gadolinium enhancement (LGE). The combined primary endpoint was defined as cardiac death, non-fatal myocardial infarction, and stroke. RESULTS 845 consecutive patients were enrolled into the study. During the median follow-up of 3.64 [1.03; 10.46] years, 61 primary endpoints occurred. Patients with primary endpoint showed larger extent of ischemia (10.7 ± 12.25% vs. 3.73 ± 8.29%, p < 0.0001) and LGE (21.09 ± 15.11% vs. 17.73 ± 10.72%, p < 0.0001). A risk prediction model containing the extent of ischemia and LGE proved to be superior in comparison to all other models (χ² increase: from 39.678 to 56.676, integrated discrimination index: 0.3851, p = 0.0033, net reclassification index: 0.11516, p = 0.0071). The ben-eficial effect of revascularization tended to be higher in patients with greater extents of ischemia, though statistical significance was not reached. CONCLUSIONS Quantification of myocardial ischemia and LGE was shown to significantly improve existing risk prediction models and might thus lead to an improvement in patient management.

Physiological changes in regional and global left-ventricular strain during exercise - a cardiac magnetic resonance imaging study using tagging and feature tracking in healthy volunteers

Background Techniques for the evaluation of regionaland global left-ventricular strain parameters are emerging in cardiac magnetic resonance (CMR) imaging. Some of these techniques require dedicated CMR sequences at the time of the imaging examination, others are based on post-processing of routine imaging. Little is known about normal values and range of these parameters, assessed by CMR. Moreover, most studies examined subjects under rest conditions only. Objective of our study was to evaluate a tagging and a feature-tracking approach in a cohort of healthy volunteers under rest conditions and during exercise.

Inter-observer agreement and diagnostic accuracy of myocardial perfusion reserve quantification by cardiovascular magnetic resonance at 3 Tesla in comparison to quantitative coronary angiography

BackgroundQuantification of cardiovascular magnetic resonance (CMR) myocardial perfusion reserve (MPR) at 1.5 Tesla has been shown to correlate to invasive evaluation of coronary artery disease (CAD) and to yield good inter-observer agreement. However, little is known about quantitative adenosine-perfusion CMR at 3 Tesla and no data about inter-observer agreement is available. Aim of our study was to evaluate inter-observer agreement and to assess the diagnostic accuracy in comparison to quantitative coronary angiography (QCA).MethodsFifty-three patients referred for coronary x-ray angiography were previously examined in a 3 Tesla whole-body scanner. Adenosine and rest perfusion CMR were acquired for the quantification of MPR in all segments. Two blinded and independent readers analyzed all images. QCA was performed in case of coronary stenosis. QCA data was used to assess diagnostic accuracy of the MPR measurements.ResultsInter-observer agreement was high for all myocardial perfusion territories (ρ = 0.92 for LAD, ρ = 0.93 for CX and RCA perfused segments). Compared to QCA receiver-operating characteristics yielded an area under the curve of 0.78 and 0.73 for RCA, 0.66 and 0.69 for LAD, and 0.52 and 0.53 for LCX perfused territories.ConclusionsInter-observer agreement of MPR quantification at 3 Tesla CMR is very high for all myocardial segments. Diagnostic accuracy in comparison to QCA yields good values for the RCA and LAD perfused territories, but moderate values for the posterior LCX perfused myocardial segments.

Cardiac Findings in Amyotrophic Lateral Sclerosis: A Magnetic Resonance Imaging Study

The objective of this study was to investigate the potential involvement of cardiac structure and function by cardiac magnetic resonance (CMR) imaging in amyotrophic lateral sclerosis (ALS) patients. Our study included 35 patients with ALS without a history of cardiac disease and an age- and gender-matched healthy control group (n = 34). All subjects received a CMR in a 1.5-T whole-body scanner. Patients were also screened with Holter monitoring, echocardiography, and a blood test of cardiac markers. Myocardial mass in ALS hearts was reduced compared to the control group, and ejection volumes in the left and right heart were severely decreased in ALS patients, as shown by echocardiography and CMR. The myocardium showed increased T1 enhancement in 77% of the patients compared to 27% of controls (p = 0.0001). A trend toward late gadolinium enhancement patterns consistent with myocardial fibrosis was observed in 23.5% of the patients (9.1% of controls). Holter monitoring was normal in all patients as well as troponin T. Cardiac involvement seems to be present in ALS patients without clinical cardiac symptoms and with a normal cardiac routine assessment. Structural myocardial defects in CMR may be due to sympathetic dysfunction and may account for reported cardiac deaths in late-stage ALS patients.

Percutaneous mitral valve repair with the MitraClip NT™ system in a patient presenting with prolonged cardiogenic shock

The MitraClip NT™ system for the treatment of severe mitral valve regurgitation is effective and safe – even for patients suffering from cardiogenic shock. The use of an intra‐aortic balloon pump expands the range of possible applications to this particular group of challenging patients.

Risk prediction in stable coronary artery disease using quantified myocardial ischemia and necrosis by cardiac magnetic resonance imaging - a prospective long-term follow-up trial

Background Until now, no consensus is reached for the standardized assessment and quantification of extent and severity of myocardial ischemia and necrosis by cardiac magnetic resonance imaging (CMR). However, there is a good evidence base suggesting that these parameters might ameliorate established risk prediction models and thus might lead to an improved management of patients with stable coronary artery disease (CAD). Objective of this study therefore is to elaborate an easy-to-use algorithm for the quantification of ischemia and necrosis and to validate the obtained data in a large cohort of CAD patients.

Reproducibility of regional- and global left-ventricular strain analyzes using tagging and feature tracking techniques - a cardiac magnetic resonance imaging study in healthy volunteers

Background Techniques for the evaluation of regionaland global left-ventricular wall motion parameters based on strain analyzes are emerging in cardiac magnetic resonance (CMR) imaging. Some of these techniques, such as tagging, require dedicated CMR sequences at the time of the examination. Other approaches are based on post-processing of routine imaging studies such as feature-tracking. Common to all is the need for specialized software solutions. Objective of our study was the evaluation of a tagging and a feature-tracking approach with regard to reproducibility and robustness. We therefore examined a cohort of healthy volunteers under rest conditions and during pharmacological exercise.

Left ventricular motion quantification parameters from tissue phase mapped MRI: influence of gender

Background Several motion parameters for quantification of LV motion abnormalities and asynchrony have been described in literature, but were investigated with different acquisition protocols and for different cohorts, thus impeding comparability. For derivation of normal values in healthy volunteers, calculation of all parameters from a single acquisition protocol is desirable. In this study, influence of gender on the motion parameters is investigated in order to determine the necessity of separate female/male normal values.

Total ischemic myocardium is a powerful predictor for adverse cardiac events

Background Imaging techniques may contribute to the proper risk assessment of patients with coronary artery disease (CAD). Especially, cardiac magnetic resonance imaging (CMR) is able to provide important prognostic information by detection of myocardial scarring (late gadolinium enhancement, LGE) and reversible ischemia. Therefore, objective of the present study was to quantify the extent of total ischemic myocardium (TIM) by the combination of LGE and reversible ischemia by CMR and to correlate the results with long-term outcome and prognosis in patients with known or suspected CAD.