Stress Perfusion Cardiac Magnetic Resonance Research Articles

Brief Research Report: Quantitative Analysis of Potential Coronary Microvascular Disease in Suspected Long-COVID Syndrome.

BackgroundCase series have reported persistent cardiopulmonary symptoms, often termed long-COVID or post-COVID syndrome, in more than half of patients recovering from Coronavirus Disease 19 (COVID-19). Recently, alterations in microvascular perfusion have been proposed as a possible pathomechanism in long-COVID syndrome. We examined whether microvascular perfusion, measured by quantitative stress perfusion cardiac magnetic resonance (CMR), is impaired in patients with persistent cardiac symptoms post-COVID-19.MethodsOur population consisted of 33 patients post-COVID-19 examined in Berlin and London, 11 (33%) of which complained of persistent chest pain and 13 (39%) of dyspnea. The scan protocol included standard cardiac imaging and dual-sequence quantitative stress perfusion. Standard parameters were compared to 17 healthy controls from our institution. Quantitative perfusion was compared to published values of healthy controls.ResultsThe stress myocardial blood flow (MBF) was significantly lower [31.8 ± 5.1 vs. 37.8 ± 6.0 (μl/g/beat), P < 0.001] and the T2 relaxation time was significantly higher (46.2 ± 3.6 vs. 42.7 ± 2.8 ms, P = 0.002) post-COVID-19 compared to healthy controls. Stress MBF and T1 and T2 relaxation times were not correlated to the COVID-19 severity (Spearman r = −0.302, −0.070, and −0.297, respectively) or the presence of symptoms. The stress MBF showed a U-shaped relation to time from PCR to CMR, no correlation to T1 relaxation time, and a negative correlation to T2 relaxation time (Pearson r = −0.446, P = 0.029).ConclusionWhile we found a significantly reduced microvascular perfusion post-COVID-19 compared to healthy controls, this reduction was not related to symptoms or COVID-19 severity.

Myocardial Contractile Mechanics in Ischemic Mitral Regurgitation: Multicenter Data Using Stress Perfusion Cardiovascular Magnetic Resonance

BackgroundLeft ventricular (LV) ischemia has been variably associated with functional mitral regurgitation (FMR). Determinants of FMR in patients with ischemia are poorly understood. ObjectivesThis study sought to test whether contractile mechanics in ischemic myocardium underlying the mitral valve have an impact on likelihood of FMR. MethodsVasodilator stress perfusion cardiac magnetic resonance was performed in patients with coronary artery disease (CAD) at multiple centers. FMR severity was confirmed quantitatively via core lab analysis. To test relationship of contractile mechanics with ischemic FMR, regional wall motion and strain were assessed in patients with inducible ischemia and minimal (≤5% LV myocardium, nontransmural) infarction. ResultsA total of 2,647 patients with CAD were studied; 34% had FMR (7% moderate or greater). FMR severity increased with presence (P < 0.001) and extent (P = 0.01) of subpapillary ischemia: patients with moderate or greater FMR had more subpapillary ischemia (odds ratio [OR]: 1.13 per 10% LV; 95% CI: 1.05-1.21; P = 0.001) independent of ischemia in remote regions (P = NS); moderate or greater FMR prevalence increased stepwise with extent of ischemia and infarction in subpapillary myocardium (P < 0.001); stronger associations between FMR and infarction paralleled greater wall motion scores in infarct-affected territories. Among patients with inducible ischemia and minimal infarction (n = 532), wall motion and radial strain analysis showed impaired subpapillary contractile mechanics to associate with moderate or greater FMR (P < 0.05) independent of remote regions (P = NS). Conversely, subpapillary ischemia without contractile dysfunction did not augment FMR likelihood. Mitral and interpapillary dimensions increased with subpapillary radial strain impairment; each remodeling parameter associated with impaired subpapillary strain (P < 0.05) independent of remote strain (P = NS). Subpapillary radial strain (OR: 1.13 per 5% [95% CI: 1.02-1.25]; P = 0.02) and mitral tenting area (OR: 1.05 per 10 mm2 [95% CI: 1.00-1.10]; P = 0.04) were associated with moderate or greater FMR controlling for global remodeling represented by LV end-systolic volume (P = NS): when substituting sphericity for LV volume, moderate or greater FMR remained independently associated with subpapillary radial strain impairment (OR: 1.22 per 5% [95% CI: 1.02-1.47]; P = 0.03). ConclusionsAmong patients with CAD and ischemia, FMR severity and adverse mitral apparatus remodeling increase in proportion to contractile dysfunction underlying the mitral valve.

Two depressed young patients with angina pectoris induced by microvascular dysfunction detected by stress perfusion cardiac magnetic resonance

Background: Recent evidence indicates a link between depression and microvascular dysfunction, which may affect therapy options and prognosis. Case summary: We described two young depressed patients with angina. No obstructive coronary heart disease was detected by computed tomography coronary angiography or invasive coronary angiography. Determined by stress perfusion cardiac MRI, these two patients were diagnosed with microvascular angina. Discussion: The two cases emphasized that depression and microvascular angina can coexist inyoung patients. Negligence of mental disorder may cause insufficient treatments. Both psycho-regulatory interventions and heart disease medicine should be options for these patients. Keywords: Microvascular angina; Depression; Stress perfusion cardiac magnetic resonance; Case report.

The effect of shexiang tongxin dropping pill on coronary microvascular dysfunction assessed by stress perfusion cardiac magnetic resonance: A case report

Although Coronary Microvascular Dysfunction (CMVD) is clinically prevalent, its therapeutic efficacy data remains uncertain. We report a 62-year-old female CMVD patients whose condition improved after Shexiang Tongxin dropping pill treatment, as confirmed by stress perfusion cardiac MRI. This case emphasizes that Shexiang Tongxin dropping pill is typically effective in the treatment of CMVD. It can not only alleviate symptoms, but also ameliorate microvascular function. Traditional Chinese medicine is a good choice for the treatment of microvascular angina.

Stress Perfusion Cardiac Magnetic Resonance in Long-Standing Non-Infarcted Chronic Coronary Syndrome with Preserved Systolic Function.

(1) Background: The impact of imaging-derived ischemia is still under debate and the role of stress perfusion cardiac magnetic resonance (spCMR) in non-high-risk patient still needs to be clarified. The aim of this study was to evaluate the impact of spCMR in a case series of stable long-standing chronic coronary syndrome (CCS) patients with ischemia and no other risk factor. (2) Methods: This is a historical prospective study including 35 patients with history of long-standing CCS who underwent coronary CT angiography (CCTA) and additional adenosine spCMR. Clinical and imaging findings were included in the analysis. Primary outcomes were HF (heart failure) and all major cardiac events (MACE) including death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, or resuscitated cardiac arrest. (3) Results: Mean follow-up was 3.7 years (IQR: from 1 to 6). Mean ejection fraction was 61 ± 8%. Twelve patients (31%) referred primary outcomes. Probability of experiencing primary outcomes based on symptoms was 62% and increased to 67% and 91% when multivessel disease and ischemia, respectively, were considered. Higher ischemic burden was predictive of disease progression (OR: 1.59, 95%CI: 1.18–2.14; p-value = 0.002). spCMR model resulted non inferior to the model comprising all variables (4) Conclusions: In vivo spCMR-modeling including perfusion and strain anomalies could represent a powerful tool in long-standing CCS, even when conventional imaging predictors are missing.

Coronary Computed Tomography Angiography Results in More Computed Tomography Chest Follow-up for Incidental Findings at 1 Year Relative to Stress-perfusion Cardiac Magnetic Resonance Imaging.

The aim of this study is to elucidate the prevalence and factors associated with follow-up chest computed tomography (CT) imaging in patients undergoing stress-perfusion cardiac magnetic resonance imaging (sCMR) and coronary CT angiography (cCTA). Cardiac imaging encounters between January 1, 2015 and May 16, 2020 were selected for analysis. Follow-up was tracked within 1-year of initial cardiac imaging, up to May 16, 2021. Patient demographics, comorbidities, and cardiopulmonary outcomes were also analyzed. Between 2015 and 2020, there were 4024 cCTA and 837 sCMR imaging procedures on unique patients with 1.1% and 0.5% of patients having follow-up CT chest studies within 1 year, respectively. When controlling for patient demographic factors, body mass index, insurance status, smoking history, and comorbid diagnostic codes, there was statistically significant increased odds (adjusted odds ratio [95% confidence interval]: 2.864 [1.129-7.265]) of undergoing follow-up within the cCTA cohort. Pulmonary nodules represented the most common incidental finding, with cCTA associated with higher rates of pulmonary nodules detected on imaging (adjusted odds ratio [95% confidence interval]: 5.947 [4.136-8.552]). sCMR was associated with higher rates of MI, percutaneous coronary intervention, and lung malignancy within 1 year, with no difference in all-cause mortality. Patients undergoing either cCTA and sCMR demonstrated a low prevalence of follow-up CT chest imaging; however, follow-up was 2 times greater after cCTA due to greater pulmonary nodule detection. Potential for follow-up should be considered when evaluating the comparative effectiveness of these modalities, including the impact of follow-up imaging on cost and patient outcomes. Strategies to improve lung nodule detection and characterization at the time of sCMR may provide added value in these patients.

Quantitative Myocardial Perfusion Predicts Outcomes in Patients With Prior SurgicalRevascularization.

Patients with previous coronary artery bypass graft (CABG) surgery typically have complex coronary disease and remain at high risk of adverse events. Quantitative myocardial perfusion indices predict outcomes in native vessel disease, but their prognostic performance in patients with prior CABG is unknown. In this study, we sought to evaluate whether global stress myocardial blood flow (MBF) and perfusion reserve (MPR) derived from perfusion mapping cardiac magnetic resonance (CMR) independently predict adverse outcomes in patients with prior CABG. This was a retrospective analysis of consecutive patients with prior CABG referred for adenosine stress perfusion CMR. Perfusion mapping was performed in-line with automated quantification of MBF. The primary outcome was a composite of all-cause mortality and major adverse cardiovascular events defined as nonfatal myocardial infarction and unplanned revascularization. Associations were evaluated with the use of Cox proportional hazards models after adjusting for comorbidities and CMR parameters. A total of 341 patients (median age 67 years, 86% male) were included. Over a median follow-up of 638days (IQR: 367-976days), 81 patients (24%) reached the primary outcome. Both stress MBF and MPR independently predicted outcomes after adjusting for known prognostic factors (regional ischemia, infarction). The adjusted hazard ratio (HR) for 1mL/g/min of decrease in stress MBF was 2.56 (95%CI: 1.45-4.35) and for 1 unit of decrease in MPR was 1.61 (95%CI: 1.08-2.38). Global stress MBF and MPR derived from perfusion CMR independently predict adverse outcomes in patients with previous CABG. This effect is independent from the presence of regional ischemia on visual assessment and the extent of previous infarction.

Cost-Minimization Analysis for Cardiac Revascularization in 12 Health Care Systems Based on the EuroCMR/SPINS Registries

ObjectivesThe aim of this study was to compare the costs of a noninvasive cardiac magnetic resonance (CMR)–guided strategy versus 2 invasive strategies with and without fractional flow reserve (FFR). BackgroundCoronary artery disease (CAD) is a major contributor to the public health burden. Stress perfusion CMR has excellent accuracy to detect CAD. International guidelines recommend as a first step noninvasive testing of patients in stable condition with known or suspected CAD. However, nonadherence in routine clinical practice is high. MethodsIn the EuroCMR (European Cardiovascular Magnetic Resonance) registry (n = 3,647, 59 centers, 18 countries) and the U.S.-based SPINS (Stress-CMR Perfusion Imaging in the United States) registry (n = 2,349, 13 centers, 11 states), costs were calculated for 12 health care systems (8 in Europe, the United States, 2 in Latin America, and 1 in Asia). Costs included diagnostic examinations (CMR and x-ray coronary angiography [CXA] with and without FFR), revascularizations, and complications during 1-year follow-up. Seven subgroup analyses covered low- to high-risk cohorts. Patients with ischemia-positive CMR underwent CXA and revascularization at the treating physician’s discretion (CMR+CXA strategy). In the hypothetical invasive CXA+FFR strategy, costs were calculated for initial CXA and FFR in vessels with ≥50% stenoses, assuming the same proportion of revascularizations and complications as with the CMR+CXA strategy and FFR-positive rates as given in the published research. In the CXA-only strategy, costs included CXA and revascularizations of ≥50% stenoses. ResultsConsistent cost savings were observed for the CMR+CXA strategy compared with the CXA+FFR strategy in all 12 health care systems, ranging from 42% ± 20% and 52% ± 15% in low-risk EuroCMR and SPINS patients with atypical chest pain, respectively, to 31% ± 16% in high-risk SPINS patients with known CAD (P < 0.0001 vs 0 in all groups). Cost savings were even higher compared with CXA only, at 63% ± 11%, 73% ± 6%, and 52% ± 9%, respectively (P < 0.0001 vs 0 in all groups). ConclusionsIn 12 health care systems, a CMR+CXA strategy yielded consistent moderate to high cost savings compared with a hypothetical CXA+FFR strategy over the entire spectrum of risk. Cost savings were consistently high compared with CXA only for all risk groups.

Long-term prognostic value of vasodilator stress cardiac magnetic resonance in patients with atrial fibrillation.

AimsAlthough the prevalence of coronary artery disease (CAD) is high among patients with atrial fibrillation (AF), studies on stress perfusion cardiac magnetic resonance (CMR) imaging frequently exclude patients with AF, and its prognostic and diagnostic value in high‐risk patients with suspected or known CAD remains unclear.Methods and resultsIn this longitudinal cohort study, we included 164 consecutive patients with AF during vasodilator perfusion CMR. Diagnostic value was evaluated regarding invasive coronary angiography in a subset of patients. We targeted a follow‐up of >5 years and used CMR results as stratification, and the primary outcome was major adverse cardiac events [MACE, cardiovascular (CV) death and myocardial infarction (MI)]. Secondary outcomes included late coronary revascularization or stroke and the components of the primary outcome. Of the whole cohort (73.8% male, mean age 72.2 years ± 7.8 SD), 99.4% were successfully scanned (163/164 patients). Median CHA2DS2‐VASc score was 4 [interquartile range (IQR) 3–5], and median 10‐year risk for CV events based on SMART risk score was high (24%, IQR 16–32%). Thirty‐two patients (19.6%) presented with ischaemia and 52 patients (31.9%) with late gadolinium enhancement (LGE). A combination of LGE and inducible ischaemia was present in 20 patients (12.3%). Diagnostic accuracy was 86.2% [confidence interval (CI) 68.3–96.1%]. The median follow‐up was 6.6 years (IQR 3.6–7.8). Ischaemia in vasodilator perfusion CMR was significantly associated with the occurrence of MACE [P < 0.01; hazard ratio (HR) 2.65, CI 1.39–5.08], as well as LGE (P = 0.03; 1.74, CI 1.07–3.64) and the combination of both (P < 0.01; HR 2.67, CI 1.59–5.62). After adjustment by age, left ventricular ejection fraction, and the presence of diabetes, ischaemia in vasodilator perfusion CMR remained significantly associated with the occurrence of MACE (2.10, CI 1.08–4.10; P = 0.03). In secondary endpoint analysis, there was a significant association of ischaemia in CMR with CV death (P < 0.05; HR 1.93, CI 0.95–3.9) and MI (P < 0.01; HR 13, CI 1.35–125.4), while no significant association was found regarding the occurrence of revascularization (P = 0.45; HR 1.43, CI 0.57–3.58) or stroke (P = 0.99; HR 0.99, CI 0.21–2.59).ConclusionsVasodilator stress perfusion CMR demonstrated an excellent diagnostic and significant prognostic value at long‐term follow‐up in high‐risk patients with persistent AF and suspected or known CAD.

Automated Quantitative Stress Perfusion Cardiac Magnetic Resonance in Pediatric Patients.

Background: Myocardial ischemia occurs in pediatrics, as a result of both congenital and acquired heart diseases, and can lead to further adverse cardiac events if untreated. The aim of this work is to assess the feasibility of fully automated, high resolution, quantitative stress myocardial perfusion cardiac magnetic resonance (CMR) in a cohort of pediatric patients and to evaluate its agreement with the coronary anatomical status of the patients.Methods: Fourteen pediatric patients, with 16 scans, who underwent dual-bolus stress perfusion CMR were retrospectively analyzed. All patients also had anatomical coronary assessment with either CMR, CT, or X-ray angiography. The perfusion CMR images were automatically processed and quantified using an analysis pipeline previously developed in adults.Results: Automated perfusion quantification was successful in 15/16 cases. The coronary perfusion territories supplied by vessels affected by a medium/large aneurysm or stenosis (according to the AHA guidelines), induced by Kawasaki disease, an anomalous origin, or interarterial course had significantly reduced myocardial blood flow (MBF) (median (interquartile range), 1.26 (1.05, 1.67) ml/min/g) as compared to territories supplied by unaffected coronaries [2.57 (2.02, 2.69) ml/min/g, p < 0.001] and territories supplied by vessels with a small aneurysm [2.52 (2.45, 2.83) ml/min/g, p = 0.002].Conclusion: Automatic CMR-derived MBF quantification is feasible in pediatric patients, and the technology could be potentially used for objective non-invasive assessment of ischemia in children with congenital and acquired heart diseases.

Prognostic Value of Stress Cardiac Magnetic Resonance in Patients With Known Coronary Artery Disease

ObjectivesThis study sought to determine whether stress cardiac magnetic resonance (CMR) provides clinically relevant risk reclassification in patients with known coronary artery disease (CAD) in a multicenter setting in the United States. BackgroundDespite improvements in medical therapy and coronary revascularization, patients with previous CAD account for a disproportionately large portion of CV events and pose a challenge for noninvasive stress testing. MethodsFrom the Stress Perfusion Imaging in the United States (SPINS) registry, we identified consecutive patients with documented CAD who were referred to stress CMR for evaluation of myocardial ischemia. The primary outcome was nonfatal myocardial infarction (MI) or cardiovascular (CV) death. Major adverse CV events (MACE) included MI/CV death, hospitalization for heart failure or unstable angina, and late unplanned coronary artery bypass graft. The prognostic association and net reclassification improvement by ischemia for MI/CV death were determined. ResultsOut of 755 patients (age 64 ± 11 years, 64% male), we observed 97 MI/CV deaths and 210 MACE over a median follow-up of 5.3 years. Presence of ischemia demonstrated a significant association with MI/CV death (HR: 2.30; 95% CI: 1.54-3.44; P < 0.001) and MACE (HR: 2.24 ([95% CI: 1.69-2.95; P < 0.001). In a multivariate model adjusted for CV risk factors, ischemia maintained strong association with MI/CV death (HR: 1.84; 95% CI: 1.17-2.88; P = 0.008) and MACE (HR: 1.77; 95% CI: 1.31-2.40; P < 0.001) and reclassified 95% of patients at intermediate pretest risk (62% to low risk, 33% to high risk) with corresponding changes in the observed event rates of 1.4% and 5.3% per year for low and high post-test risk, respectively. ConclusionsIn a multicenter cohort of patients with known CAD, CMR-assessed ischemia was strongly associated with MI/CV death and reclassified patient risk beyond CV risk factors, especially in those considered to be at intermediate risk. Absence of ischemia was associated with a <2% annual rate of MI/CV death. (Stress CMR Perfusion Imaging in the United States [SPINS] Study; NCT03192891)

Cost-Minimization analysis for cardiac revascularization in 12 healthcare systems based on the EuroCMR/SPINS registries

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): EuroCMR registry (Life Sciences GE Healthcare, Medtronic Inc., Minneapolis MN, USA; Novartis International AG, Basel, Switzerland; Siemens Healthcare, Erlangen, Germany), SPINS registry (Siemens Healthineers, Erlangen, Germany; Bayer AG, Leverkusen, Germany) Background Coronary artery disease (CAD) is a major contributor to the public health burden. Stress perfusion cardiac magnetic resonance (CMR) has an excellent accuracy to detect CAD, but data on its cost effectiveness are scarce. Purpose To compare the costs of a CMR-guided strategy vs 2 invasive strategies based on 2 large international CMR registries. Methods In the EuroCMR registry (n = 3’647, 59 centers, 18 countries) and the US-based SPINS registry (n = 2’349, 13 centers, 11 states) costs were calculated for 12 healthcare systems (8 Europe, US, 2 Latin America, 1 Asia). They included diagnostic examinations (CMR, X-ray coronarography (CXA) with/without FFR), revascularizations, and complications during a 1-year follow-up. Endpoints in both registries were all-cause and cardiovascular (CV) death, sudden cardiac death (SCD), aborted SCD, non-fatal myocardial infarction (nf-MI), and stroke. 7 sub-group analyses covered low to high-risk cohorts. Patients with ischemia-positive CMR underwent CXA and revascularization (percuteneous and surgical intervention) at the treating physician’s discretion (=CMR + CXA-strategy). In the hypothetical invasive CXA + FFR-strategy, costs were calculated for an initial CXA and an FFR in vessels with ≥50% stenoses assuming the same proportion of revascularizations/complications as in the CMR + CXA-strategy and FFR positive rates as given in the literature. In the CXA-only strategy, costs included CXA and revascularizations of ≥50% stenoses. Results Revascularizations were performed in 8.0% and 6.2% (p &amp;lt; 0.01) of SPINS and EuroCMR patients, respectively. Consistent cost savings were observed for the CMR + CXA strategy vs CXA + FFR in all 12 healthcare systems ranging from 42 ± 20% and 52 ± 15% in the low-risk EuroCMR and SPINS patients with atypical chest pain (CV-death and nf-MI 0.4-0.7%/y), respectively, to 31 ± 16% in the high-risk SPINS patients (CV-death and nf-MI 3.2%/y) with known CAD (p &amp;lt; 0.0001 vs 0 in all groups, Fig 1/2). Cost savings were even higher vs CXA-only with 63 ± 11%, 73 ± 6%, and 52 ± 9%, respectively (p &amp;lt; 0.0001 vs 0 in all groups, Fig 2). Conclusions In 12 healthcare systems, a CMR + CXA-strategy yielded consistent moderate to high cost savings compared to a hypothetical CXA + FFR-strategy over the entire spectrum of risk. Cost savings were consistently high vs a CXA-only strategy for all risk groups. Figure 1: SPINS refers to the subgroup of patients with suspected CAD (n = 1’530), EuroCMR (= suspected CAD; n = 3’647). EuroCMR vs SPINS ns. Countries per region are listed in alphabetical order. Figure 2: Top: CMR + CXA vs CXA + FFR: ANOVA: overall p = 0.0017, * vs EuroCMR typ angina: p &amp;lt; 0.005 (Scheffe post-hoc testing). Bottom: CMR + CXA vs CXA-only: ANOVA overall p &amp;lt; 0.0001, * vs SPINS with CAD and vs EuroCMR typ A: p &amp;lt; 0.0001; † vs SPINS with CAD: p &amp;lt; 0.03; ‡ vs EuroCMR typ A: p &amp;lt; 0.0001; § vs SPINS with CAD: p &amp;lt; 0.002; ║ vs EuroCMR typ: p &amp;lt; 0.002 (Scheffe post-hoc tesing)

Characteristics and long-term outcomes of patients with reduced ejection fraction referred for adenosine stress perfusion cardiac magnetic resonance imaging

Abstract Funding Acknowledgements Type of funding sources: None. Background Adenosine stress perfusion has been shown to be of minimal incremental benefit in distinguishing between ischaemic and non-ischaemic aetiology of severe left ventricular systolic dysfunction (LVSD) over and above that obtained from Cardiac Magnetic Resonance (CMR) with Late Gadolinium Enhancement (LGE). Stress CMR has, however, been shown to be effective in risk-stratifying LVSD patients, with ischaemia being an independent predictor of cardiovascular death or myocardial infarction (MI) and associated with higher rates of further intervention. Purpose Evaluate real world data from a single tertiary UK cardiac MRI centre to determine the characteristics and long-term clinical outcomes of patients with LVSD referred for stress CMR. Methods As part of an ongoing registry, all consenting patients with Ejection Fraction (EF) ≤40% and a completed adenosine stress perfusion CMR between January 2015 and December 2019 were included with prospective baseline data collection. All-cause mortality and cardiac hospitalisation, coronary angiography/revascularisation was determined from electronic hospital records. Outcomes were compared between the inducible ischaemia vs. no ischaemia groups, and LGE present vs. no LGE groups using chi square. Results The sample included 86 patients. The mean EF was 32 ± 6%. Median follow up was 3.8 years (range 41-2222 days). The indications for CMR were: 30 (35%) assess ischaemia, 35 (41%) assess LVSD aetiology and 21 (24%) LVSD assess viability. Inducible ischemia was present in 30 (35%) patients and absent in 56 (65%). Patient characteristics and outcomes are shown in Table 1. Baseline characteristics were similar between the groups but there was a higher rate of hypertension and ischaemic heart disease in the ischaemia group. There was a non-significant difference in combined mortality and cardiac hospitalisation rates between the groups (40% vs. 27% p = 0.20). LGE was present in 69 (80%) patients (28 with ischaemia; 41 without) and absent in 17 (20%, 2 with ischaemia, 15 without). The event rate was 23 (33%) vs. 4 (24%) between LGE vs. No LGE groups (p = 0.44). Of the 15 patients (17%) with no LGE or ischaemia; 2 died and 1 was hospitalised, there were no MI"s and no Percutaneous Coronary Intervention (PCI). The lack of statistical difference in event rates between ischaemia and no ischaemia groups may be due to our relatively small sample size or could reflect the effectiveness of contemporary disease modifying treatment for Heart Failure with reduced EF. Conclusion This real-world data supports published findings that in patients with LVSD and no LGE on CMR, ischaemia is very uncommon and stress CMR is unlikely to increase diagnostic yield. Conversely, if stress CMR is performed and ischaemia is absent, incidence of subsequent angiography and revascularisation is very low, which is reassuring in clinical practice. In those patients without ischaemia and LGE, likelihood of MI is low.

Feasibility and safety of quantitative adenosine stress perfusion cardiac magnetic resonance imaging in pediatric heart transplant patients with and without coronary allograft vasculopathy.

Pediatric heart transplant patients require cardiac catheterization to monitor for coronary allograft vasculopathy. Cardiac catheterization has no safe and consistent method for measuring microvascular disease. Stress perfusion cardiac magnetic resonance imaging (MRI) assessing microvascular disease has been performed in adults. To investigate the feasibility and safety of performing cardiac MRI with quantitative adenosine stress perfusion testing in pediatric heart transplant patients with and without coronary allograft vasculopathy. All pediatric heart transplant patients with coronary vasculopathy at our institution were asked to participate. Age- and gender-matched pediatric heart transplant patients without vasculopathy were recruited for comparison. Patients underwent cardiac MRI with adenosine stress perfusion testing. Sixteen pediatric heart transplant patients, ages 6-22years, underwent testing. Nine patients had vasculopathy by angiography. No heart block or other complications occurred during the study. The myocardial perfusion reserve for patients with vasculopathy showed no significant difference with comparison patients (median: 1.43 vs. 1.48; P=0.49). Values for both groups were lower than expected values based on previous adult studies. The patients were also analyzed for time after transplant and the number of rejection episodes. Patients within 6years of transplantation had a nonsignificant trend toward a higher myocardial perfusion reserve (median: 1.57) versus patients with older transplants (median: 1.47; P=0.46). Intra- and interobserver reproducibility were 97% and 92%, respectively. Myocardial perfusion reserve is a safe and feasible method for estimating myocardial perfusion in pediatric heart transplant patients. There is no reliable way to monitor microvascular disease in pediatric patients. This method shows potential and deserves investigation in a larger cohort.

Use of quantitative myocardial perfusion mapping by CMR for characterisation of ischaemia in patients post coronary artery bypass graft surgery

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): British Heart Foundation Background Quantitative myocardial perfusion mapping using Cardiac Magnetic Resonance (CMR) imaging is used for evaluation of ischaemia in the context of native vessel coronary disease, but its diagnostic performance in patients with grafts is not well established. Perfusion defects are often detected in these patients, but whether these are a consequence of a technical limitation (delayed contrast arrival from graft conduits) or a true reflection of reduced myocardial blood flow is unclear. Methods 39 patients undergoing stress perfusion CMR with previous coronary artery bypass graft (CABG) surgery, unobstructed left internal mammary artery (LIMA) grafts to the left anterior descending (LAD) artery on coronary angiography and no CMR evidence of prior LAD infarction were included. Myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) were evaluated with quantitative perfusion mapping and the factors determining MBF in the LIMA-LAD territory (AHA segments 1,2,7,8,13,14), including the impact of delayed contrast arrival through the LIMA graft were evaluated. Results In 28 out of 39 cases a myocardial perfusion defect was reported on visual assessment in LIMA-LAD myocardial territory, despite the presence of unobstructed LIMA graft and no LAD infarction. Chronic total occlusion (CTO) of the native LAD was an independent predictor of stress MBF (B=-0.36, p =0.027) and the strongest predictor of MPR (B=-0.55, p 0.005) within the LIMA-LAD myocardial territory after adjusting for age, left ventricular (LV) ejection fraction, and presence of diabetes. CTO of the native LAD was associated with a reduction in stress MBF in the basal myocardial segments (-0.57ml/g/min, p = 0.002) but had no effect on the MBF of apical segments (-0.31ml/g/min, p = 0.084). Increasing the maximum value for allowable arterial delay (TA) of contrast in the quantitative mapping algorithm resulted in a small increase in myocardial blood flow in the LIMA-LAD territory both at stress (0.07 ± 0.08ml/g/min, p &amp;lt; 0.001) and rest (0.06 ± 0.05ml/g/min, p &amp;lt; 0.001). Conclusions Perfusion defects detected in LIMA-LAD subtended territories are common despite graft patency. These defects are likely to represent genuine reduction in MBF, resulting from native LAD coronary occlusion. Prolonged contrast transit time associated with LIMA grafts results in small underestimation of MBF as measured by quantitative CMR perfusion mapping, but does not account for the degree of MBF reduction seen in these patients. Figure 1. Study patient with unobstructed LIMA to LAD graft and evidence of inducible perfusion defect in LIMA-LAD territories. (A): First pass perfusion CMR imaging. (B): Perfusion mapping showing reduced stress MBF in mid antero-septum (0.85ml/g/min) compared to the apical septum (1.65ml/g/min). (C): Late gadolinium enhancement showing no evidence of previous infarction. (D,E): Coronary angiography demonstrating unobstructed LIMA graft (D) and anastomosis site (E). Abstract Figure 1.

Additional prognostic value of vasodilator stress CMR in patients with inconclusive stress test to detect coronary artery disease

Abstract Funding Acknowledgements Type of funding sources: None. BACKGROUND Guidelines recommend performing a non-invasive testing for ischemia to diagnose coronary artery disease (CAD). However, these tests are frequently inconclusive (25%). This population has been poorly studied because of its heterogeneity. In such cases, stress cardiac magnetic resonance (CMR) may be useful to improve diagnostic certainty. To date, no study has evaluated the prognostic value of stress CMR in these patients presenting with prior inconclusive test. PURPOSE To assess the additional prognostic value of vasodilator stress perfusion CMR in patients with a first inconclusive stress test to detect CAD. METHODS Between 2008 and 2018, consecutive patients with inconclusive stress test prospectively referred for vasodilator stress perfusion CMR with dipyridamole were followed for major adverse cardiovascular events (MACE) defined as cardiac death or myocardial infarction. Inconclusive stress test was defined by echocardiography or nuclear stress testing with uncertain conclusion about the diagnosis of CAD. To characterize this population, an unsupervised clustering analysis was performed using 18 variables. Univariable and multivariable Cox regressions were performed to determine the prognostic value of inducible ischemia by stress CMR in each cluster. RESULTS Of 1502 patients with inconclusive stress test (62 ± 12 years, 59% men), 1441 (96%) completed the CMR protocol and 1397(93%) completed the follow-up (median 5.5 ± 2.3 years). Stress CMR was well tolerated without occurrence of death or severe adverse event. The clustering analysis identified 3 clusters: Cluster 1 (n = 524, 35%) had the highest prevalence of previous percutaneous coronary intervention (PCI), the highest presence of myocardial scar on CMR, the lowest LVEF(35 ± 7%) and the highest degree of LV dilatation. Cluster 2 (n = 406, 27%) had the highest prevalence of previous coronary artery bypass grafting (CABG), preserved LVEF(54 ± 10%), absence of LV dilatation and rate of male(89%). Cluster 3 (n = 572, 38%) had the lowest rate of previous PCI/CABG and of myocardial scar. This cluster gathered the oldest patients (73 ± 11 years), predominantly female (60%), with the highest rate of atrial fibrillation and body mass index. Survival analysis found significant differences across clusters for the occurrence of MACE (p = 0.02). Moreover, inducible ischemia was significantly associated with the occurrence of MACE in each cluster (cluster 1, HR 2.28; [95%CI: 1.31-3.99]; p = 0.0028; cluster 2, HR 3.37; [95%CI, 1.97-5.75]; p &amp;lt; 0.0001; cluster 3, HR 2.73; [95%CI, 1.67-4.46]; p &amp;lt; 0.0001). In multivariable Cox regression, inducible ischemia was an independent predictor of a higher incidence of MACE in each cluster (p &amp;lt; 0.001). CONCLUSIONS Cluster analysis identified 3 different phenotypes of patients with inconclusive stress test that were associated with distinct clinical and prognostic profiles. Within these clusters, CMR stress has an additional prognostic value to predict the occurrence of MACE. Abstract Figure. Kaplan-Meier for MACE in each cluster

Prognostic value of vasodilator stress perfusion cardiovascular magnetic resonance (CMR) in patients with previous coronary artery bypass graft (CABG)

The accuracy and prognostic value of stress perfusion cardiac magnetic resonance (CMR) are well established in patients with suspected or proven coronary artery disease (CAD). Because myocardial contrast kinetics may be altered in patients with previous coronary artery bypass graft (CABG), most studies have excluded those patients in whom prognostic data are missing. To assess the prognostic value of vasodilator stress perfusion CMR in patients with previous CABG. Between 2008 and 2018, we prospectively included consecutive patients with CABG referred for vasodilator stress perfusion CMR with dipyridamole. They were followed for the occurrence of major adverse cardiovascular events (MACE) defined by cardiovascular death, non-fatal myocardial infarction or late coronary revascularisation > 90 days. Univariable and multivariable Cox regressions were performed to determine the prognostic association of inducible ischemia and late gadolinium enhancement (LGE). Of 866 CABG patients (70 ± 9 years, 89% men), 852 (98%) completed the CMR protocol and 771 (89%) completed the follow-up (median 4.2 ± 2.7 years). Stress CMR was well tolerated without severe adverse event. Overall, 531 (61%) patients had a myocardial infarction defined by the presence of LGE with ischemic patterns. Using Kaplan–Meier analyses, the presence of myocardial ischemia was correlated with the occurrence of MACE and cardiac mortality (both P < 0.0001) ( Fig. 1 ). In multivariable stepwise Cox regression, the absence of inducible ischemia was an independent predictor of a lower incidence of MACE (HR: 2.17, 95% CI: 1.56–3.13; P < 0.001) and cardiovascular mortality (HR: 2.38; 95% CI: 0.25–4.03; P = 0.001). Stress CMR is feasible, safe and has a good discriminative prognostic value to predict the occurrence of MACE and cardiovascular mortality in patients with CABG.

Prognostic value of vasodilator stress perfusion CMR in patients with previous coronary artery bypass graft.

The accuracy and prognostic value of stress perfusion cardiac magnetic resonance (CMR) are established in coronary artery disease (CAD) patients. Because myocardial contrast kinetics may be altered after coronary artery bypass graft (CABG), most studies excluded CABG patients. This study aimed to assess the prognostic value of vasodilator stress perfusion CMR in CABG patients. Consecutive CABG patients referred for stress CMR were retrospectively included and followed for the occurrence of major adverse cardiovascular events (MACE) including cardiovascular (CV) death or non-fatal myocardial infarction (MI). Cox regression analyses were performed to determine the prognostic association of inducible ischaemia and late gadolinium enhancement (LGE) by CMR. Of 866 consecutive CABG patients, 852 underwent the stress CMR protocol and 771 (89%) completed the follow-up [median (interquartile range) 4.2 (3.3-6.2) years]. There were 85 MACE (63 CV deaths and 22 non-fatal MI). Using Kaplan-Meier analysis, the presence of inducible ischaemia identified the occurrence of MACE [hazard ratio (HR) 3.52, 95% confidence interval (CI): 2.27-5.48; P < 0.001] and CV death (HR 2.55, 95% CI: 1.52-4.25; P < 0.001). In a multivariable stepwise Cox regression including clinical characteristics and CMR indexes, the presence of inducible ischaemia was an independent predictor of a higher incidence of MACE (HR 3.22, 95% CI: 2.06-5.02; P < 0.001) and CV death (HR 2.15, 95% CI: 1.28-3.62; P = 0.003), and the same was observed for LGE (both P = 0.02). Stress CMR has a good discriminative prognostic value in patients after CABG, with a higher incidence of MACE and CV death in patients with inducible ischaemia and/or LGE.

Long-Term Prognosis of Patients With Coronary Microvascular Disease Using Stress Perfusion Cardiac Magnetic Resonance

ObjectivesThis study investigated the prognosis of coronary microvascular disease (CMD) as determined by stress perfusion cardiac magnetic resonance (CMR) in patients with ischemic symptoms but without significant coronary artery disease (CAD). BackgroundPatients with CMD have poorer prognosis with various cardiac diseases. The myocardial perfusion reserve index (MPRI) derived from noninvasive stress perfusion CMR has been established to diagnose microvascular angina with a threshold MPRI <1.4. The prognosis of CMD as determined by MPRI is unknown. MethodsChest pain patients without epicardial CAD or myocardial disease from January 2009 to December 2017 were retrospectively included from 3 imaging centers in Hong Kong (HK). Stress perfusion CMR examinations were performed using either adenosine or adenosine triphosphate. Adequate stress was assessed by achieving splenic switch-off sign. Measurement of MPRI was performed in all stress perfusion CMR scans. Patients were followed for major adverse cardiovascular events defined as all-cause death, acute coronary syndrome (ACS), epicardial CAD development, heart failure hospitalization and non-fatal stroke. ResultsA total of 218 patients were studied (mean age 59 ± 12 years; 49.5% male) and the average MPRI of that cohort was 1.56 ± 0.33. Females and a history of hyperlipidemia were predictors of lower MPRI. Major adverse cardiovascular events (MACE) occurred in 15.6% of patients during a median follow-up of 5.5 years (interquartile range: 4.6 to 6.8 years). The optimal cutoff value of MPRI in predicting MACE was found with a threshold MPRI ≤1.47. Patients with MPRI ≤1.47 had three-fold increased risk of MACE compared with those with MPRI >1.47 (hazard ratio [HR]: 3.14; 95% confidence interval [CI]: 1.58 to 6.25; p = 0.001). Multivariate Cox regression after adjusting for age and hypertension demonstrated that MPRI was an independent predictor of MACE (HR: 0.10; 95% CI: 0.03 to 0.34; p < 0.001). ConclusionsStress perfusion CMR-derived MPRI is an independent imaging marker that predicts MACE in patients with ischemic symptom and no overt CAD over the medium term.

Stress perfusion cardiac magnetic resonance imaging to identify coronary aneurysms, ischaemia and fibrosis in adult patients with convalescent Kawasaki disease

Abstract Background Kawasaki disease is a common cause of coronary aneurysms in early adulthood. Non-invasive imaging plays a crucial role in the diagnosis and surveillance of these patients who are known to develop ischaemia, premature coronary artery disease and have poorer long-term health outcomes. Stress perfusion cardiac MRI (CMR) is considered the “gold standard” for the assessment of ischaemia and risk stratification of major adverse cardiovascular events in patients with coronary artery disease. Its use in the long-term follow-up of patients with Kawasaki disease is particularly attractive as it avoids the use of ionising radiation. However, data on its utility, together with magnetic resonance angiography (MRA) and late gadolinium enhancement (LGE) to identify ischaemia, coronary aneurysms, and fibrosis, over long-term follow-up in this population remains limited. Purpose To evaluate the diagnostic utility of comprehensive non-invasive stress perfusion CMR to identify inducible ischaemia, coronary aneurysms and myocardial fibrosis in adult patients with convalescent Kawasaki disease. Methods We performed a retrospective review of all adult patients in our Kawasaki service who underwent stress perfusion CMR with MRA and LGE as part of routine clinical care. Data collected included the presence of inducible perfusion defects, coronary anatomy and LGE. Data was compared to contemporary CT coronary angiography (CTCA). In patients who had repeated stress perfusion CMR, changes in perfusion over time were investigated. Results Seventeen patients underwent stress perfusion CMR (total 30 scans). Seven patients underwent ≥2 scans. Median age was 21 years; 14 patients were male. Five patients (30%) had areas of inducible hypoperfusion of which 3 also had LGE. A further 2 patients had LGE with no ischaemia. Coronary MRA was performed in 12 patients (71%) and identified 14 aneurysms. In 8 patients with both MRA and CTCA, detection of aneurysms was significantly correlated (Pearson's coefficient 0.776; P value 0.024). Of the 5 patients with ischaemia, 4 patients had previous CABG. All areas of ischaemia corresponded to persistent calcified aneurysms in the responsible artery. In the 7 patients with multiple perfusion CMR scans (median follow-up 47 months), 3 patients developed new ischaemia. Conclusions Long-term surveillance of coronary arteries in adult patients with a childhood history of Kawasaki disease is crucial in the early identification and management of complications. We show that stress perfusion CMR is a useful radiation-free technique for the long-term follow-up of these young patients and is able to identify the development of new ischaemia. Coronary MRA has good agreement in the identification of aneurysms when compared to CTCA. Little is reported in the literature regarding the use of a comprehensive CMR assessment in the follow-up of adult patients with Kawasaki disease and further studies are needed to validate this approach. Funding Acknowledgement Type of funding source: None