Dobutamine Stress Cardiac Magnetic Resonance Research Articles

Kiosk 1R-TB-01 - Prognostic Value and Safety of Dobutamine Stress Cardiac Magnetic Resonance in Patients with Prior Coronary Artery Bypass Grafting

Kiosk 1R-TB-01 - Prognostic Value and Safety of Dobutamine Stress Cardiac Magnetic Resonance in Patients with Prior Coronary Artery Bypass Grafting

Kiosk 1R-TB-03 - Safety and Outcome of Patients with Left Ventricular Thrombus Undergoing Dobutamine or Adenosine Stress Cardiac Magnetic Resonance Imaging

Kiosk 1R-TB-03 - Safety and Outcome of Patients with Left Ventricular Thrombus Undergoing Dobutamine or Adenosine Stress Cardiac Magnetic Resonance Imaging

Safety, accuracy, and prediction of prognosis in patients with end-stage chronic kidney disease undergoing dobutamine stress cardiac magnetic resonance imaging.

Advanced chronic kidney disease (CKD) is an independent risk factor for coronary artery disease (CAD). Due to its unique uremia-derived pathophysiology of atherosclerosis and the limitations of using potentially harmful contrast agents, the best non-invasive approach to assess CAD in these patients remains unclear. We sought to investigate the accuracy, safety, and prognosis of patients with severe CKD undergoing dobutamine stress cardiac magnetic resonance imaging (CMR). In this retrospective, single-center study, patients on dialysis or with a glomerular filtration rate of <15 ml/min/1.73 m2 who underwent dobutamine stress CMR were included. A rest and stress wall motion analysis was performed using dobutamine/atropine as stressor. The target heart rate was 85% of the maximum heart rate. Periprocedural adverse events and 1-year follow-up data were obtained. A total of 176 patients (127 men, 49 women) with a mean age of 60.9 ± 14.7 years were included, of which 156 patients were on permanent dialysis. Short-term symptoms such as angina or shortness of breath during stress CMR were frequent (22.1%), but major complications were rare (one patient with myocardial infarction, 0.6%). The 1-year event rate was high (16.4%) with a significant independent correlation to reduced ejection fraction at rest (p = 0.037) and failure to achieve the target heart rate (p = 0.029). The overall accuracy for predicting significant CAD was good (sensitivity of 71.4%, specificity of 98.4%) and excellent if the target heart rate was achieved (83.3%, 97.9%). A negative stress CMR was highly predictive for the absence of major adverse cardiac event or any coronary revascularization during the 1-year follow-up (negative predictive value of 95.0%). Dobutamine stress CMR is a safe and accurate diagnostic imaging technique in patients at advanced stages of chronic kidney disease. A reduced ejection fraction and the inability to reach the target heart rate are independent predictors of a poor outcome.

Value of myocardial deformation parameters for detecting significant coronary artery disease.

Introduction: The study aimed to evaluate the diagnostic value of global and regional myocardial deformation parameters derived from two-dimensional speckle-tracking echocardiography to detect functionally significant coronary artery stenosis. Methods: Dobutamine stress echocardiography and cardiac magnetic resonance myocardial perfusion imaging (CMR-MPI) were performed on 145 patients with a moderate and high probability of coronary artery disease (CAD) and LVEF≥55%. Significant CAD was defined as>50% stenosis of the left main stem,>70% stenosis in a major coronary vessel, or in the presence of intermediate stenosis (50-69%) validated as hemodynamically significant by CMRMPI. Patients were divided in two groups: non-pathological (48.3%) vs pathological (51.7%), according to CAG and CMR-MPI results. Afterwards, off-line speckle-tracking analysis was performed to analyse myocardial deformation parameters. Results: There were no differences in myocardial deformation parameters at rest between groups, except global longitudinal strain (GLS) and global radial strain (GRS) were significantly lower in the CAD (+) group: -21.3±2.2 vs.-16.3±2.3 (P<0.001) and 39.7±23.2 vs. 24.5±15.8 (P<0.001). GLS and regional longitudinal strain rate (SR) had the highest diagnostic value at high dobutamine dose with AUC of 0.902 and 0.878, respectively. At early recovery, GLS was also found to be the best myocardial deformation parameter with a sensitivity of 78%, specificity 67%, AUC 0.824. Conclusion: Global and regional myocardial deformation parameters are highly sensitive and specific in detecting functionally significant CAD. The combination of deformation parameters and WMA provides an incremental diagnostic value for patients with a moderate and high probability of CAD, especially the combination with regional longitudinal SR.

Associations between blood biomarkers, cardiac function and adverse outcome in a young tetralogy of Fallot cohort

BackgroundTo determine the potential prognostic value and clinical correlations of blood biomarkers in a cohort of patients with Tetralogy of Fallot (TOF). MethodsIn the setting of multicenter prospective research studies TOF patients underwent blood sampling, cardiopulmonary exercise testing and low-dose dobutamine stress cardiac magnetic resonance (CMR) imaging. In the blood sample NT-proBNP, GDF-15, Galectin-3, ST-2, DLK-1, FABP4, IGFBP-1, IGFBP-7, MMP-2, and vWF were assessed. During subsequent follow-up, patients were evaluated for reaching the study endpoint (cardiac death, arrhythmia-related hospitalization or cardioversion/ablation, VO2 max ≤65% of predicted). Regression analysis was used to explore the correlation between blood biomarkers (corrected for age and gender) and other clinical parameters. The potential predictive value of blood biomarkers and events were assessed with Kaplan-Meier analysis and Cox proportional hazard analysis. ResultsWe included 137 Fallot patients, median age 19.2 (interquartile range: 14.6–25.7) years, median age at TOF-repair 0.9 (0.5–1.9) years. After a median follow-up of 8.7 (6.3–10.7) years, 20 (14.6%) patients reached the composite endpoint. In a multivariable cox-regression analysis corrected for age at study baseline, elevated IGFBP-7 and MMP-2 levels were associated with the composite endpoint. We also noted a correlation between DLK-1 and relative change in right ventricular end systolic volume during dobutamine stress CMR (β = −0.27, p = 0.010), a correlation between FABP4 and Max VO2 (β = −0.41, p ≤0.001 and between MMP-2 and tricuspid valve E/A ratio (β = −0.15, p = 0.037). ConclusionsIGFBP-7, MMP-2 and DLK-1 levels are related to cardiac function and long-term outcome in TOF patients.

Safety of Stress Cardiac Magnetic Resonance in Patients With Moderate to Severe Aortic Valve Stenosis.

Dobutamine and adenosine stress cardiac magnetic resonance (CMR) imaging is relatively contraindicated in patients with moderate to severe aortic valve stenosis (AS). We aimed to determine the safety of dobutamine and adenosine stress CMR in patients with moderate to severe AS. In this retrospective study patients with AS who underwent either dobutamine or adenosine stress CMR for exclusion of obstructive coronary artery disease were enrolled. We recorded clinical data, CMR and echocardiography findings, and complications as well as minor symptoms. Patients with AS were compared to matched individuals without AS. A total of 187 patients with AS were identified and compared to age-, gender- and body mass index-matched 187 patients without AS. No severe complications were reported in the study nor the control group. The reported frequency of non-severe complications and minor symptoms were similar between the study and the control groups. Nineteen patients with AS experienced non-severe complications or minor symptoms during dobutamine stress CMR compared to eighteen patients without AS (p = 0.855). One patient with AS and two patients without AS undergoing adenosine stress CMR experienced minor symptoms (p = 0.562). Four examinations were aborted because of chest pain, paroxysmal atrial fibrillation and third-degree atrioventricular block. Inducible ischaemia, prior coronary artery bypass grafting, prior stroke and age were associated with a higher incidence of complications and minor symptoms. Moderate to severe AS was not associated with complications during CMR stress test. The incidence of non-severe complications and minor symptoms was greater with dobutamine.

Dobutamine stress cardiac MRI is safe and feasible in pediatric patients with anomalous aortic origin of a coronary artery (AAOCA)

BackgroundRisk stratification in anomalous aortic origin of a coronary artery (AAOCA) is challenged by the lack of a reliable method to detect myocardial ischemia. We prospectively studied the safety and feasibility of Dobutamine stress-cardiac magnetic resonance (DSCMR), a test with excellent performance in adults, in pediatric patients with AAOCA. MethodsConsecutive DSCMR from 06/2014–12/2019 in patients≤20 years old with AAOCA were included. Hemodynamic response and major/minor events were recorded. Image quality and spatial/temporal resolution were evaluated. Rest and stress first-pass perfusion and wall motion abnormalities (WMA) were assessed. Inter-observer agreement was assessed using kappa coefficient. ResultsA total of 224 DSCMR were performed in 182 patients with AAOCA at a median age of 14 years (IQR 12, 16) and median weight of 58.0 kg (IQR 43.3, 73.0). Examinations were completed in 221/224 (98.9%), all studies were diagnostic. Heart rate and blood pressure increased significantly from baseline (p < 0.001). No patient had major events and 28 (12.5%) had minor events. Inducible hypoperfusion was noted in 31/221 (14%), associated with WMA in 13/31 (42%). Inter-observer agreement for inducible hypoperfusion was very good (Κ = 0.87). Asymptomatic patients with inducible hypoperfusion are considered high-risk and those with a negative test are of standard risk. ConclusionsDSCMR is feasible in pediatric patients with AAOCA to assess for inducible hypoperfusion and WMA. It can be performed safely with low incidence of major/minor events. Thus, DSCMR is potentially a valuable test for detection of myocardial ischemia and helpful in the management of this patient population.

Abstract 15115: Clinical Presentation and Medium-term Outcomes in Anomalous Aortic Origin of the Left Coronary Artery: High-risk Features Beyond Interarterial Course

Background: Anomalous aortic origin of the left coronary artery (AAOLCA) confers a rare, but significant, risk of sudden cardiac death (SCD) in children. Surgical intervention is recommended for AAOLCA with an interarterial course, with other subtypes considered benign. We aimed to determine the clinical characteristics and outcomes of AAOLCA in a prospective cohort following a standardized approach. Methods: All patients with AAOLCA &lt;20 years old were prospectively enrolled. Anatomic details were obtained with coronary computerized tomography angiography (CTA). Myocardial functional studies were obtained under provocative stress, including exercise stress test, stress nuclear perfusion imaging, or dobutamine stress cardiac magnetic resonance. Patients were stratified as high-risk if: 1) episode of aborted SCD, 2) interarterial and/or intramural course, or 3) evidence of myocardial ischemia on functional studies. Results: A total of 47 patients (32 male, 68%) with AAOLCA were enrolled, median age 12 [IQR 6.0;15.0] years. Of these, 20 had exertional symptoms (42.5%) and 5 had aborted SCD (10.5%). Thirty-one patients (79%) were classified high-risk, 28% low-risk, and 3 (6%) work-up is ongoing. Of patients with completed work-up, 16/43 (37%) had inducible ischemia and, of these, 2/16 (13%) presented without symptoms and one with aborted SCD as the first symptom. Two patients in our cohort had AAOLCA arising close to the noncoronary sinus, just above the left and noncoronary commissure, resulting in ostial stenosis: one presented with aborted SCD and another with left ventricular dysfunction. To date, 17 patients have undergone repair, median age 10 years [IQR 6.6;15.7]. Median follow-up was 3.9 [IQR 1.3;6.3] years with no significant symptoms and all but 4 patients are cleared from exercise restrictions. Conclusion: AAOLCA may present with diverse anatomic configuration and risk stratification is essential to determine management. AAOLCA from the noncoronary sinus may also present with myocardial ischemia and, thus, be classified as high-risk. A multimodality imaging approach is necessary to adequately risk stratify this population. All patients are alive at last follow-up and the majority free from exercise restriction.

July 2020 at a glance: focus on imaging and cardiomyopathies

Data on epidemiology of cardiomyopathies are limited.1-3 Merlo et al.4 showed a reduction in mortality, heart transplantation, left ventricular (LV) assist device implantation and sudden cardiac death in the last decade, compared with the previous ones, in patients with non-ischaemic dilated cardiomyopathy (DCM). Outcomes were also dependent on specific phenotypes with the poorest in patients with chemotherapy-induced DCM and the best in those with tachycardia-induced DCM. An analysis of the Swedish Heart Failure (HF) Register of the young patients with HF, compared with the others, showed that patients aged <55 years were more likely to have DCM, obesity, congenital heart disease, and a low LV ejection fraction (LVEF). Patients aged <55 years had a five times higher mortality risk compared with control subjects with the highest risk in the youngest ones, 18-34 years old.5 Diabetes is a known risk factor for cardiovascular death in patients with a recent myocardial infarction.6 Shin et al.7 showed the independent prognostic value for HF hospitalizations or cardiovascular death of glycated haemoglobin (A1C) levels (adjusted hazard ratio 1.11, 95% confidence interval 1.01–1.21 per 1% higher A1C) and LVEF in patients with type 2 diabetes and a recent acute coronary syndrome. Cardiac magnetic resonance (CMR) has a major role in the detection and quantification of myocardial fibrosis and adipose tissue, two major determinants of the phenotype and outcomes of patients with HF and preserved ejection fraction (HFpEF).8, 9 Quarta et al.10 review the role of CMR in the management of HFpEF patients. Tayal et al.11 used CMR to evaluate LV reverse remodelling in DCM. Absolute LV contractile reserve by dobutamine stress CMR and female gender predicted LVEF increase over 12 months. Nauta et al.12 retrospectively evaluated the association between LV geometry, clinical and biomarker phenotypes, and therapeutic response in patients with chronic HF. Compared to patients with an eccentric hypertrophy pattern, those with a concentric one had a different clinical and biomarker phenotype and did not benefit from the up-titration of beta-blockers and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Left ventricular ejection time (LVET) was an independent predictor of HF in a community-based cohort studied by echocardiography.13 Patel et al.14 explored its prognostic role in 545 HF outpatients stratified by LVEF. LVET was shorter in HF patients with reduced ejection fraction (HFrEF) vs. those with HFpEF and its longer duration was independently associated with better 1-year outcomes in HFrEF but not in HFpEF patients. Left atrial (LA) structure and function are major determinants of outcomes in patients with HF and atrial fibrillation.15, 16 LA diameter predicted 4-year mortality also in HF patients with mitral regurgitation treated by percutaneous repair.17 Impaired LA strain may contribute to reduced exercise capacity.18 Sugimoto et al.19 showed that a blunted LA strain is associated with lower stroke volume and cardiac output response to exercise and worse outcomes in HF patients. Pulmonary hypertension and right ventricular dysfunction are major prognostic markers in HF and valve disease.20-23 Santiago-Vacas et al.24 assessed the long-term trajectories of systolic pulmonary artery pressure (SPAP), tricuspid annular plane systolic excursion (TAPSE) and TAPSE/SPAP ratio in 1557 HF patients. These parameters were independent determinants of outcomes and increasing SPAP and declining TAPSE and TAPSE/SPAP ratio in the preceding period were associated with higher mortality. Sodium–glucose co-transporter type 2 inhibitors were found to reduce HF events25, 26 and are studied in major clinical trials in HF patients.27-30 A pre-specified analysis from the Dapagliflozin And Prevention of Adverse-outcomes in HF (DAPA-HF) study showed the lack of interaction between LVEF and the beneficial effect of dapagliflozin on outcomes in HFrEF patients.31 Breast cancer therapies can lead to late-onset HF.32 A pro-inflammatory state, detected by biomarker measurements, can cause cardiac dysfunction even 10 years after treatment in breast cancer survivors.33 Heart rate is a major prognostic marker, especially in patients in sinus rhythm.34, 35 Anker et al.36 identified elevated resting heart rate as associated with increased levels of HF biomarkers and poor outcomes in treatment-naïve cancer patients.

Hemodynamic Forces at Rest and Stress vs. Adenosine and Dobutamine Stress Cardiac Magnetic Resonance

Hemodynamic Forces at Rest and Stress vs. Adenosine and Dobutamine Stress Cardiac Magnetic Resonance

Ventricular response to dobutamine stress cardiac magnetic resonance imaging is associated with adverse outcome during 8-year follow-up in patients with repaired Tetralogy of Fallot.

AimsThe aim of this study was to evaluate the possible value of dobutamine stress cardiac magnetic resonance imaging (CMR) to predict adverse outcome in Tetralogy of Fallot (TOF) patients.Methods and resultsIn previous prospective multicentre studies, TOF patients underwent low-dose dobutamine stress CMR (7.5 µg/kg/min). Subsequently, during regular-care patient follow-up, patients were assessed for reaching the composite endpoint (cardiac death, arrhythmia-related hospitalization, or cardioversion/ablation, VO2 max ≤65% of predicted). A normal stress response was defined as a decrease in end-systolic volume (ESV) and increase in ejection fraction. The relative parameter change during stress was calculated as relative parameter change = [(parameterstress − parameterrest)/parameterrest] * 100. The predictive value of dobutamine stress CMR for the composite endpoint was determined using time-to-event analyses (Kaplan–Meier) and Cox proportional hazard analysis. We studied 100 patients [67 (67%) male, median age at baseline CMR 17.8 years (interquartile range 13.5–34.0), age at TOF repair 0.9 years (0.6–2.1)]. After a median follow-up of 8.6 years (6.7–14.1), 10 patients reached the composite endpoint. An abnormal stress response (30% vs. 4.4%, P = 0.021) was more frequently observed in composite endpoint patients. Also in endpoint patients, the relative decrease in right ventricular ESV decreased less during stress compared with the patients without an endpoint (−17 ± 15 vs. −26 ± 13 %, P = 0.045). Multivariable analyses identified an abnormal stress response (hazard ratio 10.4; 95% confidence interval 2.5–43.7; P = 0.001) as predictor for the composite endpoint.ConclusionAn abnormal ventricular response to dobutamine stress is associated with adverse outcome in patients with repaired TOF.

Assessment of myocardial ischemia by strain dobutamine stress echocardiography and cardiac magnetic resonance perfusion imaging before and after coronary artery bypass grafting.

Following coronary artery bypass grafting (CABG), testing for myocardial ischemia by noninvasive imaging is often hampered by false-positive results. The aim of this study was to find test parameters with the best potential to identify myocardial ischemia in post-CABG patients. Fifty-two consecutive patients scheduled for CABG, underwent both dobutamine stress echocardiography (DSE) and cardiac magnetic resonance first-pass perfusion imaging (CMR-FPPI) with adenosine vasodilation, before and 8-10months after the surgical revascularization. A pathologic biphasic stress response (PBR) expresses the presence of contractile reserve during low-dose dobutamine that decreases to hypo- or akinesia provoked by high-dose dobutamine. During DSE, potential PBR, segmental wall-motion score (WMS) as well as peak-systolic longitudinal strain (PLS) at peak-dose dobutamine were assessed. Post-CABG, there was still a relatively high prevalence of ischemia-positive segments evaluated by deformation imaging, but the number of such segments was significantly lower by PBR (20% and 22%) compared with peak-dose strain and WMS (62% and 77%, respectively; P<.05). The use of PBR instead of peak-dose WMS and strain could reduce the number of false-positive test results post-CABG. Among all imaging modalities tested, PBR by WMS and strain may be useful parameters for identifying patients with the need for new revascularization. We furthermore found that DSE may be interpreted as positive when revealing at least three ischemia-positive segments. The sensitivity of these test modalities for detecting coronary restenosis needs to be determined in further studies on a cohort of symptomatic post-CABG patients.

Incremental cost-effectiveness of dobutamine stress cardiac magnetic resonance imaging in patients at intermediate risk for coronary artery disease.

AimsThe effectiveness of stress cardiac magnetic resonance (CMR) as a gatekeeper for coronary angiography (CA) has been established. Level five HTA studies according to the hierarchical model of diagnostic test evaluation are not available.MethodsThis cohort study included 1,158 consecutive patients (mean age 63 ± 11 years, 42 % women) presenting at our institution between January 1, 2003 and December 31, 2004 with suspected coronary artery disease (CAD) for an elective CA. The patients were assessed for eligibility and propensity score matching was applied to address selection bias regarding the patients’ allocation to CMR or direct CA. Median patient follow-up was 7.9 years (95 % CI 7.8–8.0 years). The primary effect was calculated as relative survival difference. The cost unit calculation (per patient) at our institute was the source of costs.ResultsSurvival was similar in CMR and CA (p = 0.139). Catheterizations ruling out CAD were significantly reduced by the CMR gate-keeper strategy. Patients with prior CMR had significantly lower costs at the initial hospital stay and at follow-up (CMR vs. CA, initial: 2,904€ vs. 3,421€, p = 0.018; follow-up: 2,045€ vs. 3,318€, p = 0.037). CMR was cost-effective in terms of a contribution of 12,466€ per life year to cover a part of the CMR costs.ConclusionStress CMR prior to CA was saving 12,466€ of hospital costs per life year. Lower costs at follow-up suggest sustained cost-effectiveness of the CMR-guided strategy.Electronic supplementary materialThe online version of this article (doi:10.1007/s00392-014-0793-0) contains supplementary material, which is available to authorized users.

Comprehensive Dobutamine Stress CMR Versus Echocardiography in LBBB and Suspected Coronary Artery Disease

This study aimed to compare dobutamine stress cardiac magnetic resonance (DSCMR) withdobutamine stress echocardiography (DSE) in patients with left bundle branch block (LBBB) and suspected coronary artery disease (CAD). Noninvasive diagnosis of CAD in patients with pre-existent LBBB is difficult because single-photon emission computed tomography and stress echocardiography both have limitations. We hypothesized that a comprehensive DSCMR examination including cine, perfusion, and late gadolinium enhancement imaging would be more accurate than DSE, thus potentially reducing the number of unnecessary invasive coronary angiograms. We prospectively evaluated 82 consecutive patients with LBBB referred to our cardiology clinic for investigation of suspected CAD. All 82 patients underwent DSE, DSCMR, and invasive quantitative coronary angiography within 14 days. We compared the diagnostic accuracy of DSE, CMR cine imaging, the additive value of first-pass perfusion, and late gadolinium enhancement. In the comprehensive examination, a positive result was adjudged as the presence of either subendocardial or transmural late gadolinium enhancement with or without inducible peri-infarct ischemia or an inducible perfusion defect corresponding to an inducible regional wall motion abnormality. CMR cine imaging (regional wall motion abnormalities) had higher specificity, negative predictive value, and overall diagnostic accuracy than did DSE (87.5% vs. 72.9%; 80.8% vs. 67.3%; and 80.4% vs. 72.0%, respectively), although sensitivity was the same (72.0%). The addition of first-pass stress perfusion and late gadolinium enhancement (scar) further improved diagnostic confidence (sensitivity 82.4%, specificity 95.8%, positive predictive value 93.3%, negative predictive value 88.5%, and diagnostic accuracy 90.2%). DSCMR is a safe procedure and has greater diagnostic accuracy than does DSE in assessing patients with suspected CAD and LBBB. A comprehensive examination with the addition of perfusion and late gadolinium enhancement to CMR cine imaging significantly boosted specificity and sensitivity, making DSCMR a reliable alternative to invasive quantitative coronary angiography in this group of patients.

Safety and feasibility of dobutamine stress cardiac magnetic resonance for cardiovascular assessment prior to renal transplantation

Current guidelines recommend cardiovascular risk assessment prior to renal transplantation. There is currently no evidence for the role of cardiovascular magnetic resonance (CMR) in this population, despite an established evidence base in the non-chronic kidney disease (CKD) population. Our aim is to determine the feasibility and safety of dobutamine stress CMR (DSCMR) imaging in the risk stratification of CKD patients awaiting renal transplantation. CKD patients who were deemed at high risk for coronary artery disease (CAD) and awaiting renal transplantation underwent DSCMR. Forty-one patients whose median age was 56 years (range 28–73 years) underwent DSCMR. Nineteen were undergoing haemodialysis, 10 peritoneal dialysis and 12 pre-dialysis. The aetiology of the renal failure was diabetes mellitus in 29%, glomerulonephritis in 24%, hypertension in 22% and autosomal dominant polycystic kidney disease in 10%. Thirty-eight patients (93%) achieved the end point, either positive for ischaemia or negative, achieving at least 85% of age-predicted heart rate. Two of them did not achieve target heart rate and one was discontinued because of severe headache. Of the 38 patients who achieved the end point, 35 (92%) were negative for inducible wall motion abnormalities and four (10%) were positive. There were no serious adverse effects. DSCMR is a well tolerated and viable investigation for the cardiovascular risk stratification of high-risk CKD patients prior to renal transplantation. DSCMR already has an established evidence base in the non-CKD population with superiority over other noninvasive techniques. Larger studies with outcome data are now required to define its true utility in the CKD population.

Dobutamine stress cardiac MRI reliably predicts significant coronary disease in renal transplant candidates

Background Coronary artery disease (CAD) accounts for half of all deaths in patients with end stage kidney disease (ESKD) who have undergone renal transplantation. In patients with ESKD, “angiographically” significant CAD may be asymptomatic. Identification of these patients, with subsequent revascularisation, may reduce the prevalence of adverse cardiovascular events in the peri-transplant and post-transplant period. We aimed to evaluate the effectiveness of diagnostic (>85% maximum age-predicted heart rate) dobutamine stress cardiac magnetic resonance (DSCMR) imaging in identifying “angiographically” significant CAD in asymptomatic patients.

Value of strain analysis with feature tracking in dobutamine stress cardiac magnetic resonance imaging for detecting coronary artery disease

Background Dobutamine stress magnetic resonance (DSMR) has been established for the detection of coronary artery disease (CAD) due to its high diagnostic accuracy and prognostic value. The novel technique feature tracking (FT) analyses regional myocardial strain and thereby offers detailed information about myocardial deformation. The purpose of this study was to examine how FT based circumferential strain (CS) compares to visually detected wall motion abnormalities (WMA) during DSMR and whether it adds beneficial information for detecting CAD. Methods A total of 25 patients (72% male; mean age 64 ± 8) with suspected or known CAD underwent a standardized high-dose DSMR protocol at 1.5 T. CMR images were acquired at rest and during stress in three short-axis views (SAX; apical, medial, basal). None of the patients had evidence for WMAs or impaired left ventricular function at rest or scar tissue based on late gadolinium enhancement (LGE). For strain analysis the SAX planes were divided into 16 segments (n = 400 segments). All patients underwent x-ray coronary angiography for clinical reasons. Patients without WMA during DSMR and exclusion of CAD by coronary angiography were defined as normal and served as control (10 patients, 160 segments). 15 patients developed WMA during DSMR (34 segments). Additionally, based on angiographic findings, segments that were supplied by a vessel with >75% were defined as stenotic (64 segments). The remaining segments, which did not develop a WMA or were supplied by a vessel <50% narrowing, were considered as remote segments (161 segments). Results At rest no differences in CS were observed between groups (normal: -28.1 ± 8.9; WMA: -24.8 ± 12.9; stenotic: 25.8 ± 10.6; remote: 27.7 ± 11.7%; p = 0.23). High dose dobutamine stress revealed highly significant differences between normal segments and segments with WMA (normal: -39.3 ± 11.3%; WMA: 19.2 ± 19.1%; p < 0.001) as well as between normal and stenotic and normal and remote segments (stenotic: -23.8 ± 15.9%, p < 0.001; remote: -34.2 ± 14.1%, p < 0.001). Additionally, analysis of the absolute change in CS between rest and stress showed significant differences for normal segments vs. segments with WMA (Δ normal: -11.2 ± 12.6%, Δ WMA: 5.6 ± 22.9%; p = 0.001), as well as between normal and stenotic segments (Δ stenotic: 1.9 ± 18.4%; p < 0.001) and between normal and remote segments (Δ remote: -6.6 ± 16.3%; p = 0.027). CS results are summarized in Figure 1. ROC analysis of CS during maximum DSMR differentiated normal from stenotic segments with a sensitivity of 75% and specificity of 67% using a cutoff -33.2% with an area under the curve of 0.78 (Figure 2). Conclusions FT based CS analysis demonstrated significant differences between normal segments and segments with WMA in DSMR. Additionally, FT detected significantly impaired CS in stenotic segments compared to normal segments. FT based CS may improve the diagnostic accuracy of DSMR for detection of ischemia.

Dobutamine stress cardiac magnetic resonance versus echocardiography for the assessment of outcome in patients with suspected or known coronary artery disease. Are the two imaging modalities comparable?

PurposeTo compare the value of Dobutamine stress echocardiography (DSE) with that provided by Dobutamine Cardiac Magnetic Resonance (DCMR) for the non-invasive risk stratification of patients with suspected or known coronary artery disease (CAD). MethodsPatients with suspected or known CAD underwent either DSE or DCMR using the same standardized protocol. Patient matching was then performed retrospectively for age, gender and risk factors. Outcome data including cardiac death and non-fatal myocardial infarction (defined as hard cardiac events) and ‘late’ revascularization performed >90days after the diagnostic procedures were collected during at least 6months. ResultsFollow-up data were available in 1852 patients who completed either DSE (n=884) or DCMR (n=884) during a mean follow-up duration of 4.1±2.4 and 3.9±1.9years, respectively (p=NS). Matched patients exhibited an overall high risk profile (69±9years; 69% male, 70% history of CAD and 26% diabetes mellitus in both groups). Using multivariable analysis, both modalities successfully identified patients with inducible ischemia at higher risk for subsequent hard cardiac events, surpassing the value of conventional risk factors like age, male gender and diabetes (HR=9.2; 95%CI=5.6–14.9 for DCMR versus 2.5; 95%CI=1.7–3.7 for DSE). By testing for interaction the predictive capacity of DCMR was higher than that provided by DSE (p=0.02). Patients with negative DCMR exhibited lower event rates compared to those with negative DSE (annual hard cardiac event rate of 0.8% versus 3.2%, p=0.002). ConclusionsDSE & DCMR aid the risk stratification of CAD patients. However, inducible WMA during DCMR are associated with a higher risk for subsequent cardiac events. Patients with negative DCMR on the other hand, exhibited a lower event rate compared to those with negative DSE.

Cost-effectiveness of dobutamine stress cardiac magnetic resonance imaging in stable coronary artery disease - a post-hoc analysis

Background Dobutamine stress cardiac magnetic resonance imaging (DCMR) was not an established test for coronary ischemia in 2003/2004. Meanwhile, long-term outcome has demonstrated a strong prognostic value of negative DCMR testing (Kelle et al. JACC CVI 2011). However, only limited data are as yet available about reimbursement for and costeffectiveness of DCMR in patients with stable coronary artery disease (CAD).

Mitral Valve Regurgitation: Paradoxical Behavior of Dobutamine Stress Cardiac Magnetic Resonance Imaging

A 62-year-old woman with mitral regurgitation (MR) underwent cardiac magnetic resonance (CMR) and dobutamine stress CMR imaging, a widely used method to analyze left ventricular function and MR volumes. During dobutamine provocation at escalating doses, the left ventricular end-diastolic diameter (LVEDD) decreased, with a corresponding decrease in MR. At peak dobutamine dose, the LVEDD further decreased, with near complete relief of MR. Upon cessation of dobutamine provocation, the MR returned to predobutamine level. This case thereby demonstrates that MR may be reversible under certain conditions.