Impact of Epicardial Adipose Tissue on Infarct Size and Left Ventricular Systolic Function in Patients with Anterior ST-Segment Elevation Myocardial Infarction.

We aimed to assess the correlation of cardiovascular magnetic resonance (CMR)-derived epicardial adipose tissue (EAT) with infarct size (IS) and residual systolic function in ST-segment elevation myocardial infarction (STEMI). We enrolled patients discharged for a first anterior reperfused STEMI submitted to undergo CMR. EAT, left ventricular (LV) ejection fraction (LVEF), and IS were quantified at the 1-week (n = 221) and at 6-month CMR (n = 167). At 1-week CMR, mean EAT was 31 ± 13 mL/m2. Patients with high EAT volume (n = 72) showed larger 1-week IS. After adjustment, EAT extent was independently related to 1-week IS. In patients with large IS at 1 week (>30% of LV mass, n = 88), those with high EAT showed more preserved 6-month LVEF. This association persisted after adjustment and in a 1:1 propensity score-matched patient subset. Overall, EAT decreased at 6 months. In patients with large IS, a greater reduction of EAT was associated with more preserved 6-month LVEF. In STEMI, a higher presence of EAT was associated with a larger IS. Nevertheless, in patients with large infarctions, high EAT and greater subsequent EAT reduction were linked to more preserved LVEF in the chronic phase. This dual and paradoxical effect of EAT fuels the need for further research in this field.

Impact of Persistent Microvascular Obstruction Late After STEMI on Adverse LV Remodeling: A CMR Study.

BACKGROUND: Little is known about the occurrence and implications of persistent microvascular obstruction (MVO) after reperfused ST-segment elevation myocardial infarction (STEMI). OBJECTIVES: The authors used cardiac magnetic resonance (CMR) to characterize the impact of persistent MVO on adverse left ventricular remodeling (ALVR). METHODS: A prospective registry of 471 STEMI patients underwent CMR 7 (IQR: 5-10) days and 198 (IQR: 167-231) days after infarction. MVO (≥1 segment) and ALVR (relative increase >15% at follow-up CMR) of left ventricular end-diastolic index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were determined. RESULTS: One-week MVO occurred in 209 patients (44%) and persisted in 30 (6%). The extent of MVO (P = 0.026) and intramyocardial hemorrhage (P = 0.001) at 1 week were independently associated with the magnitude of MVO at follow-up CMR. Compared with patients without MVO (n = 262, 56%) or with MVO only at 1 week (n = 179, 38%), those with persistent MVO at follow-up (n = 30, 6%) showed higher rates of ALVR-LVEDVI (22%, 27%, and 50%; P = 0.003) and ALVR-LVESVI (20%, 21%, and 53%; P < 0.001). After adjustment, persistent MVO at follow-up (≥1 segment) was independently associated with ΔLVEDVI (relative increase, %) (P < 0.001) and ΔLVESVI (P < 0.001). Compared with a 1:1 propensity score-matched population on CMR variables made up of 30 patients with MVO only at 1 week, patients with persistent MVO more frequently displayed ALVR-LVEDVI (12% vs 50%; P = 0.003) and ALVR-LVESVI (12% vs 53%; P = 0.001). CONCLUSIONS: MVO persists in a small percentage of patients in chronic phase after STEMI and exerts deleterious effects in terms of LV remodeling. These findings fuel the need for further research on microvascular injury repair.

Reference ventricular dimensions and function parameters by cardiovascular magnetic resonance in highly trained Caucasian athletes.

BACKGROUND: Data regarding cardiovascular magnetic resonance (CMR) reference values in athletes have not been well determined yet. Using CMR normal reference values derived from the general population may be misleading in athletes and may have clinical implications. AIMS: To determine reference ventricular dimensions and function parameters and ratios by CMR in high performance athletes. METHODS: Elite athletes and age- and gender-matched sedentary healthy controls were included. Anatomical and functional variables, including biventricular volumes, mass, systolic function, wall thickness, sphericity index and longitudinal function were determined by CMR. RESULTS: A total of 148 athletes (29.2 ± 9.1 years; 64.8% men) and 124 controls (32.1 ± 10.5 years; 67.7% men) were included. Left ventricular (LV) mass excluding papillary muscles was 67 ± 13 g/m2 in the control group and increased from 65 ± 14 g/m2 in the low intensity sport category to 83 ± 16 g/m2 in the high cardiovascular demand sport category; P < 0.001. Regarding right ventricular (RV) mass, the data were 20 ± 5, 31 ± 6, and 38 ± 8 g/m2, respectively; P < 0.001. LV and RV volumes, and wall thickness were higher in athletes than in the control group, and also increased with sport category. However, LV and RV ejection fractions were similar in both groups. LV and RV dimensions, wall thickness and LV/RV ratios reference parameters for athletes are provided. CONCLUSIONS: LV and RV masses, volumes, and wall thicknesses are higher in athletes than in sedentary subjects. Specific CMR reference ranges for athletes are provided and can be used as reference levels, rather than the standard upper limits used for the general population to exclude cardiomyopathy.

MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure.

BACKGROUND: Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF). PURPOSE: To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI. STUDY TYPE: Prospective. POPULATION: Multicenter registry of 759 reperfused STEMI patients (23.3% elderly). FIELD STRENGTH/SEQUENCE: 1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences. ASSESSMENT: One-week MRI-derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI-derived LVEF as preserved (p-LVEF, ≥50%), mildly reduced (mr-LVEF, 41%-49%), or reduced (r-LVEF, ≤40%). Median follow-up was 5 [2.33-7.54] years. STATISTICAL TESTS: Univariable (Student's t, Mann-Whitney U, chi-square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous-time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant. RESULTS: Over the follow-up period, 79 (10.4%) patients presented AHF. MRI-LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91-0.98]) and elderly patients (HR 0.94 [0.91-0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p-LVEF) was noted in patients with r-LVEF both in nonelderly (HR 11.25 [5.67-22.32]) and elderly patients (HR 7.55 [3.29-17.34]). However, the mr-LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54-8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients. DATA CONCLUSION: MRI-derived p-LVEF confers a favorable prognosis and r-LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr-LVEF category in the elderly group. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.

Cardiac magnetic resonance outperforms echocardiography to predict subsequent implantable cardioverter defibrillator therapies in ST-segment elevation myocardial infarction patients.

Background: Implantable cardioverter defibrillators (ICD) are effective as a primary prevention measure of ventricular tachyarrhythmias in patients with ST-segment elevation myocardial infarction (STEMI) and depressed left ventricular ejection fraction (LVEF). The implications of using cardiac magnetic resonance (CMR) instead of echocardiography (Echo) to assess LVEF prior to the indication of ICD in this setting are unknown. Materials and methods: We evaluated 52 STEMI patients (56.6 ± 11 years, 88.5% male) treated with ICD in primary prevention who underwent echocardiography and CMR prior to ICD implantation. ICD implantation was indicated based on the presence of heart failure and depressed LVEF (≤ 35%) by echocardiography, CMR, or both. Prediction of ICD therapies (ICD-T) during follow-up by echocardiography and CMR before ICD implantation was assessed. Results: Compared to echocardiography, LVEF was lower by cardiac CMR (30.2 ± 9% vs. 37.4 ± 7.6%, p < 0.001). LVEF ≤ 35% was detected in 24 patients (46.2%) by Echo and in 42 (80.7%) by CMR. During a mean follow-up of 6.1 ± 4.2 years, 10 patients received appropriate ICD-T (3.16 ICD-T per 100 person-years): 5 direct shocks to treat very fast ventricular tachycardia or ventricular fibrillation, 3 effective antitachycardia pacing (ATP) for treatment of ventricular tachycardia, and 2 ineffective ATP followed by shock to treat ventricular tachycardia. Echo-LVEF ≤ 35% correctly predicted ICD-T in 4/10 (40%) patients and CMR-LVEF ≤ 35% in 10/10 (100%) patients. CMR-LVEF improved on Echo-LVEF for predicting ICD-T (area under the curve: 0.76 vs. 0.48, p = 0.04). Conclusion: In STEMI patients treated with ICD, assessment of LVEF by CMR outperforms Echo-LVEF to predict the subsequent use of appropriate ICD therapies.

Risk of death associated with incident heart failure in patients with known or suspected chronic coronary syndrome.

AIMS: Traditional adverse events in chronic coronary syndrome (CCS) include atherothrombotic events but usually exclude heart failure (HF). Data are scarce about how new-onset HF modifies mortality risk. We aimed to determine the incidence of HF and compare its long-term mortality risk with myocardial infarction (MI) and stroke in patients with known or suspected CCS. METHODS: We prospectively evaluated 5811 consecutive HF-free patients submitted to vasodilator stress cardiac magnetic resonance (CMR) for known or suspected CCS. Ischaemic burden and left ventricular ejection fraction were assessed by CMR. HF included outpatient diagnosis or acute HF hospitalization. The mortality risk for the incident events and their cross-comparisons were evaluated using a Markov illness-death model with transition-specific survival models. RESULTS: The mean age was 55 ± 11 years, and 38.9% were female. At a median follow-up of 5.44 (IQR = 2.53-8.55) years, 591 deaths were registered (1.79 per 100 P-Y). The rates of new-onset HF were higher compared with MI and stroke [1.02, 0.62, and 0.51, respectively (P < 0.05)]. The adjusted association between new-onset HF, MI, and stroke, and subsequent mortality was time dependent. The risk increased almost linearly for HF and became significant by the third year. By Year 10, the mortality risk attributable to new-onset HF was more than 2.5-fold (HR: 2.68, 95% CI = 1.74-4.12). For MI, there was a significant increase in mortality risk up to the second year, followed by a monotonic decrease. For stroke, the mortality risk increased for the entire follow-up but became significant by the third year. A cross-comparison among incident endpoints HF outnumbers risk for those with MI by the sixth year (HRyear6.3 : 1.88, 95% CI = 1.03-3.43). There was no difference in mortality risk between incident HF and stroke. CONCLUSIONS: In patients with CCS, long-term rates of incident HF were higher than MI and stroke. Patients with new-onset HF showed a higher risk of long-term mortality.

Residual ST-segment elevation to predict long-term clinical and CMR-derived outcomes in STEMI.

Residual ST-segment elevation after ST-segment elevation myocardial infarction (STEMI) has traditionally been considered a predictor of left ventricular (LV) dysfunction and ventricular aneurism. However, the implications in terms of long-term prognosis and cardiac magnetic resonance (CMR)-derived structural consequences are unclear. A total of 488 reperfused STEMI patients were prospectively included. The number of Q wave leads with residual ST-segment elevation > 1 mm (Q-STE) at pre-discharge ECG was assessed. LV ejection fraction (LVEF, %) and infarct size (IS, % of LV mass) were quantified in 319 patients at 6-month CMR. Major adverse cardiac events (MACE) were defined as all-cause death and/or re-admission for acute heart failure (HF), whichever occurred first. During a mean follow-up of 6.1 years, 92 MACE (18.9%), 39 deaths and 53 HF were recorded. After adjustment for baseline characteristics, Q-STE (per lead with > 1 mm) was independently associated with a higher risk of long-term MACE (HR 1.24 [1.07-1.44] per lead, p = 0.004), reduced (< 40%) LVEF (HR 1.36 [1.02-1.82] per lead, p = 0.04) and large (> 30% of LV mass) IS (HR 1.43 [1.11-1.85] per lead, p = 0.006) at 6-month CMR. Patients with Q-STE ≥ 2 leads (n = 172, 35.2%) displayed lower MACE-free survival, more depressed LVEF, and larger IS at 6-month CMR (p < 0.001 for all comparisons). Residual ST-segment elevation after STEMI represents a universally available tool that predicts worse long-term clinical and CMR-derived structural outcomes.

Prognostic value of cardiac magnetic resonance early after ST-segment elevation myocardial infarction in older patients.

BACKGROUND: older patients with ST-segment elevation myocardial infarction (STEMI) represent a very high-risk population. Data on the prognostic value of cardiac magnetic resonance (CMR) in this scenario are scarce. METHODS: the registry comprised 247 STEMI patients over 70 years of age treated with percutaneous intervention and included in a multicenter registry. Baseline characteristics, echocardiographic parameters and CMR-derived left ventricular ejection fraction (LVEF, %), infarct size (% of left ventricular mass) and microvascular obstruction (MVO, number of segments) were prospectively collected. The additional prognostic power of CMR was assessed using adjusted C-statistic, net reclassification index (NRI) and integrated discrimination improvement index (IDI). RESULTS: during a 4.8-year mean follow-up, the number of first major adverse cardiac events (MACE) was 66 (26.7%): 27 all-cause deaths and 39 re-admissions for acute heart failure. Predictors of MACE were GRACE score (HR 1.03 [1.02-1.04], P < 0.001), CMR-LVEF (HR 0.97 [0.95-0.99] per percent increase, P = 0.006) and MVO (HR 1.24 [1.09-1.4] per segment, P = 0.001). Adding CMR data significantly improved MACE prediction compared to the model with baseline and echocardiographic characteristics (C-statistic 0.759 [0.694-0.824] vs. 0.685 [0.613-0.756], NRI = 0.6, IDI = 0.08, P < 0.001). The best cut-offs for independent variables were GRACE score > 155, LVEF < 40% and MVO ≥ 2 segments. A simple score (0, 1, 2, 3) based on the number of altered factors accurately predicted the MACE per 100 person-years: 0.78, 5.53, 11.51 and 78.79, respectively (P < 0.001). CONCLUSIONS: CMR data contribute valuable prognostic information in older patients submitted to undergo CMR soon after STEMI. The Older-STEMI-CMR score should be externally validated.

End-systole and end-diastole detection in short axis cine MRI using a fully convolutional neural network with dilated convolutions.

The correct assessment and characterization of heart anatomy and functionality is usually done through inspection of magnetic resonance image cine sequences. In the clinical setting it is especially important to determine the state of the left ventricle. This requires the measurement of its volume in the end-diastolic and end-systolic frames within the sequence trough segmentation methods. However, the first step required for this analysis before any segmentation is the detection of the end-systolic and end-diastolic frames within the image acquisition. In this work we present a fully convolutional neural network that makes use of dilated convolutions to encode and process the temporal information of the sequences in contrast to the more widespread use of recurrent networks that are usually employed for problems involving temporal information. We trained the network in two different settings employing different loss functions to train the network: the classical weighted cross-entropy, and the weighted Dice loss. We had access to a database comprising a total of 397 cases. Out of this dataset we used 98 cases as test set to validate our network performance. The final classification on the test set yielded a mean frame distance of 0 for the end-diastolic frame (i.e.: the selected frame was the correct one in all images of the test set) and 1.242 (relative frame distance of 0.036) for the end-systolic frame employing the optimum setting, which involved training the neural network with the Dice loss. Our neural network is capable of classifying each frame and enables the detection of the end-systolic and end-diastolic frames in short axis cine MRI sequences with high accuracy.

Sex Effect in the Decision to Perform Invasive Coronary Angiography in Patients With Chronic Coronary Syndrome After Undergoing Vasodilator Stress MRI.

BACKGROUND: Stress cardiac MRI permits comprehensive evaluation of patients with known or suspected chronic coronary syndromes (CCS). The impact of sex on the use of invasive cardiac angiography (ICA) after vasodilator stress cardiac MRI is unclear. PURPOSE: To evaluate the impact of sex on ICA use after vasodilator stress cardiac MRI. STUDY TYPE: Retrospective. POPULATION: A total of 6229 consecutive patients (age [mean ± standard deviation] 65.2 ± 11.5 years, 38.1% women). FIELD STRENGTH/SEQUENCE: A 5-T; a steady-state free-precession cine sequence; stress first-pass perfusion imaging; late enhancement imaging. ASSESSMENT: Patients underwent vasodilator stress cardiac MRI for known or suspected CCS. The ischemic burden (at stress first-pass perfusion imaging) was computed (17-segment model). STATISTICAL TESTS: Multivariate logistic regression was used to evaluate the potential differential association between ischemic burden and use of cardiac MRI-related ICA across sex. RESULTS: A total of 1109 (17.8%) patients were referred to ICA, among which there were significantly more men (762, 19.7%) than women (347, 14.6%). Overall, after multivariate adjustment, female sex was not associated with lower use of ICA (odds ratio [OR] = 0.99; confidence interval [CI] 95%: 0.84-1.18, P = 0.934). However, significant sex differences were detected across ischemic burden. Whereas women with nonischemic vasodilator stress cardiac MRI (0 ischemic segments) were less commonly submitted to ICA (OR = 0.49; CI 95%: 0.35-0.69) in patients with ischemia (>1 ischemic segment), adjusted use of ICA was more frequent in women than men (OR = 1.27; CI 95%: 1.1-1.5). DATA CONCLUSIONS: In patients with known or suspected CCS submitted to undergo vasodilator stress cardiac MRI, cardiac MRI-related ICA may be overused in men without ischemia. Furthermore, ICA referral in patients with negative ischemia resulted in greater odds of revascularization in men. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 5.

Short-Term Changes in Left and Right Ventricular Cardiac Magnetic Resonance Feature Tracking Strain Following Ferric Carboxymaltose in Patients With Heart Failure: A Substudy of the Myocardial-IRON Trial.

Background The mechanisms explaining the clinical benefits of ferric carboximaltose (FCM) in patients with heart failure, reduced or intermediate left ventricular ejection fraction, and iron deficiency remain not fully clarified. The Myocardial-IRON trial showed short-term cardiac magnetic resonance (CMR) changes suggesting myocardial iron repletion following administration of FCM but failed to find a significant increase in left ventricular ejection fraction in the whole sample. Conversely, the strain assessment could evaluate more specifically subtle changes in contractility. In this subanalysis, we aimed to evaluate the effect of FCM on the short-term left and right ventricular CMR feature tracking derived strain. Methods and Results This is a post hoc subanalysis of the double-blind, placebo-controlled, randomized clinical trial that enrolled 53 ambulatory patients with heart failure and left ventricular ejection fraction <50%, and iron deficiency [Myocardial-IRON trial (NCT03398681)]. Three-dimensional left and 2-dimensional right ventricular CMR tracking strain (longitudinal, circumferential, and radial) changes were evaluated before, 7 and 30 days after randomization using linear mixed-effect analysis. The median (interquartile range) age of the sample was 73 years (65-78), and 40 (75.5%) were men. At baseline, there were no significant differences in CMR feature tracking strain parameters across both treatment arms. At 7 days, the only global 3-dimensional left ventricular circumferential strain was significantly higher in the FCM treatment-arm (difference: -1.6%, P=0.001). At 30 days, and compared with placebo, global 3-dimensional left ventricular strain parameters significantly improved in those allocated to FCM treatment-arm [longitudinal (difference: -2.3%, P<0.001), circumferential (difference: -2.5%, P<0.001), and radial (difference: 4.2%, P=0.002)]. Likewise, significant improvements in global right ventricular strain parameters were found in the active arm at 30 days (longitudinal [difference: -3.3%, P=0.010], circumferential [difference: -4.5%, P<0.001], and radial [difference: 4.5%, P=0.027]). Conclusions In patients with stable heart failure, left ventricular ejection fraction <50%, and iron deficiency, treatment with FCM was associated with short-term improvements in left and right ventricular function assessed by CMR feature tracking derived strain parameters. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03398681.

Magnetic Resonance Assessment of Left Ventricular Ejection Fraction at Any Time Post-Infarction for Prediction of Subsequent Events in a Large Multicenter STEMI Registry.

BACKGROUND: Magnetic resonance imaging (MRI) is the most accurate imaging technique for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of LVEF assessment at any time after ST-segment elevation myocardial infarction (STEMI) for subsequent major adverse cardiac event (MACE) prediction is uncertain. PURPOSE: To explore the prognostic impact of MRI-derived LVEF at any time post-STEMI to predict subsequent MACE (cardiovascular death or re-admission for acute heart failure). STUDY TYPE: Prospective. POPULATION: One thousand thirteen STEMI patients were included in a multicenter registry. FIELD STRENGTH/SEQUENCE: 1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences. ASSESSMENT: Post-infarction MRI-derived LVEF (reduced [r]: <40%; mid-range [mr]: 40%-49%; preserved [p]: ≥50%) was sequentially quantified at 1 week and after >3 months of follow-up. STATISTICAL TESTS: Multi-state Markov model to determine the prognostic value of each LVEF state (r-, mr- or p-) at any time point assessed to predict subsequent MACE. A P-value <0.05 was considered to be statistically significant. RESULTS: During a 6.2-year median follow-up, 105 MACE (10%) were registered. Transitions toward improved LVEF predominated and only r-LVEF (at any time assessed) was significantly related to a higher incidence of subsequent MACE. The observed transitions from r-LVEF, mr-LVEF, and p-LVEF states to MACE were: 15.3%, 6%, and 6.7%, respectively. Regarding the adjusted transition intensity ratios, patients in r-LVEF state were 4.52-fold more likely than those in mr-LVEF state and 5.01-fold more likely than those in p-LVEF state to move to MACE state. Nevertheless, no significant differences were found in transitions from mr-LVEF and p-LVEF states to MACE state (P-value = 0.6). DATA CONCLUSION: LVEF is an important MRI index for simple and dynamic post-STEMI risk stratification. Detection of r-LVEF by MRI at any time during follow-up identifies a subset of patients at high risk of subsequent events. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 2.

Combined assessment of stress cardiovascular magnetic resonance and angiography to predict the effect of revascularization in chronic coronary syndrome patients.

AIMS: The role of revascularization in chronic coronary syndrome (CCS) and the value of ischaemia vs. anatomy to guide decision-making are in constant debate. We explored the potential of a combined assessment of ischaemic burden by vasodilator stress cardiovascular magnetic resonance (CMR) and presence of multivessel disease by angiography to predict the effect of revascularization on all-cause mortality in CCS. METHODS AND RESULTS: The study group comprised 1066 CCS patients submitted to vasodilator stress CMR pre-cardiac catheterization (mean age 66 ± 11 years, 69% male). Stress CMR-derived ischaemic burden (extensive if >5 ischaemic segments) and presence of multivessel disease in angiography (two- or three-vessel or left main stem disease) were computed. The influence of revascularization on all-cause mortality was explored and adjusted hazard ratios (HRs) with the corresponding 95% confidence intervals were obtained. During a median 7.51-year follow-up, 557 (52%) CMR-related revascularizations and 308 (29%) deaths were documented. Revascularization exerted a neutral effect on all-cause mortality in the whole study group [HR 0.94 (0.74-1.19), P = 0.6], in patients without multivessel disease [n = 598, 56%, HR 1.12 (0.77-1.62), P = 0.6], and in those with multivessel disease without extensive ischaemic burden [n = 181, 17%, HR 1.66 (0.91-3.04), P = 0.1]. However, compared to non-revascularized patients, revascularization significantly reduced all-cause mortality in patients with simultaneous multivessel disease and extensive ischaemic burden (n = 287, 27%): 3.77 vs. 7.37 deaths per 100 person-years, HR 0.60 (0.40-0.90), P = 0.01. CONCLUSIONS: In patients with CCS submitted to catheterization, evidence of simultaneous extensive CMR-related ischaemic burden and multivessel disease identifies the subset in whom revascularization can reduce all-cause mortality.

Stress cardiac magnetic resonance for mortality prediction and decision-making: registry of 2496 elderly patients with chronic coronary syndrome.

INTRODUCTION AND OBJECTIVES: The management of elderly patients with chronic coronary syndrome (CCS) is challenging. We explored the prognostic value and usefulness for decision-making of ischemic burden determined by vasodilator stress cardiac magnetic resonance (CMR) imaging in elderly patients with known or suspected CCS. METHODS: The study group comprised 2496 patients older than 70 years who underwent vasodilator stress CMR for known or suspected CCS. The ischemic burden (number of segments with stress-induced perfusion deficit) was calculated following the 17-segment model. Subsequently, we retrospectively analyzed its association with all-cause mortality and the effect of CMR-guided revascularization. RESULTS: During a median follow-up of 4.58 years, there were 430 deaths (17.2%). A higher ischemic burden was an independent predictor of mortality (HR, 1.04; 95%CI, 1.01-1.07 for each additional ischemic segment; P=.006). This association was also found in patients older than 80 years and in women (P <.001). An interaction between revascularization and mortality was detected toward deleterious consequences at low ischemic burden and a protective effect in patients with extensive ischemia. CONCLUSIONS: Vasodilator stress CMR is a valuable tool to stratify risk in elderly patients with CCS and might be helpful to guide decision-making in this scenario.

EpCAM and microvascular obstruction in patients with STEMI: a cardiac magnetic resonance study.

INTRODUCTION AND OBJECTIVES: Microvascular obstruction (MVO) is negatively associated with cardiac structure and worse prognosis after ST-segment elevation myocardial infarction (STEMI). Epithelial cell adhesion molecule (EpCAM), involved in epithelium adhesion, is an understudied area in the MVO setting. We aimed to determine whether EpCAM is associated with the appearance of cardiac magnetic resonance (CMR)-derived MVO and long-term systolic function in reperfused STEMI. METHODS: We prospectively included 106 patients with a first STEMI treated with percutaneous coronary intervention, quantifying serum levels of EpCAM 24hours postreperfusion. All patients underwent CMR imaging 1 week and 6 months post-STEMI. The independent correlation of EpCAM with MVO, systolic volume indices, and left ventricular ejection fraction was evaluated. RESULTS: The mean age of the sample was 59±13 years and 76% were male. Patients were dichotomized according to median EpCAM (4.48 pg/mL). At 1-week CMR, lower EpCAM was related to extensive MVO (P=.021) and larger infarct size (P=.019). At presentation, EpCAM values were significantly associated with the presence of MVO in univariate (OR, 0.58; 95%CI, 0.38-0.88; P=.011) and multivariate logistic regression models (OR, 0.55; 95%CI, 0.35-0.87; P=.010). Although MVO tends to resolve at chronic phases, decreased EpCAM was associated with worse systolic function: reduced left ventricular ejection fraction (P=.009) and higher left ventricular end-systolic volume (P=.043). CONCLUSIONS: EpCAM is associated with the occurrence of CMR-derived MVO at acute phases and long-term adverse ventricular remodeling post-STEMI.

Risk score for early risk prediction by cardiac magnetic resonance after acute myocardial infarction.

BACKGROUND: Cardiac magnetic resonance (CMR) performed early after ST-segment elevation myocardial infarction (STEMI) can improve major adverse cardiac event (MACE) risk prediction. We aimed to create a simple clinical-CMR risk score for early MACE risk stratification in STEMI patients. METHODS: We performed a multicenter prospective registry of reperfused STEMI patients (n = 1118) in whom early (1-week) CMR-derived left ventricular ejection fraction (LVEF), infarct size and microvascular obstruction (MVO) were quantified. MACE was defined as a combined clinical endpoint of cardiovascular (CV) death, non-fatal myocardial infarction (NF-MI) or re-admission for acute decompensated heart failure (HF). RESULTS: During a median follow-up of 5.52 [2.63-7.44] years, 216 first MACE (58 CV deaths, 71 NF-MI and 87 HF) were registered. Mean age was 59.3 ± 12.3 years and most patients (82.8%) were male. Based on the four variables independently associated with MACE, we computed an 8-point risk score: time to reperfusion >4.15 h (1 point), GRACE risk score > 155 (3 points), CMR-LVEF <40% (3 points), and MVO >1.5 segments (1 point). This score permitted MACE risk stratification: MACE per 100 person-years was 1.96 in the low-risk category (0-2 points), 5.44 in the intermediate-risk category (3-5 points), and 19.7 in the high-risk category (6-8 points): p < 0.001 in multivariable Cox survival analysis. CONCLUSIONS: A novel risk score including clinical (time to reperfusion >4.15 h and GRACE risk score > 155) and CMR (LVEF <40% and MVO >1.5 segments) variables allows for simple and straightforward MACE risk stratification early after STEMI. External validation should confirm the applicability of the risk score.

Predictive Value of Cardiac Magnetic Resonance Feature Tracking after Acute Myocardial Infarction: A Comparison with Dobutamine Stress Echocardiography.

In acute ST-segment elevation myocardial infarction (STEMI) late gadolinium enhancement (LGE) may underestimate segmental functional recovery. We evaluated the predictive value of cardiac magnetic resonance (CMR) feature-tracking (FT) for functional recovery and whether it incremented the value of LGE compared to low-dose dobutamine stress echocardiography (LDDSE) and speckle-tracking echocardiography (STE). Eighty patients underwent LDDSE and CMR within 5-7 days after STEMI and segmental functional recovery was defined as improvement in wall-motion at 6-months CMR. Optimal conventional and FT parameters were analyzed and then also applied to an external validation cohort of 222 STEMI patients. Circumferential strain (CS) was the strongest CMR-FT predictor and addition to LGE increased the overall accuracy to 74% and was especially relevant in segments with 50-74% LGE (AUC 0.60 vs. 0.75, p = 0.001). LDDSE increased the overall accuracy to 71%, and in the 50-74% LGE subgroup improved the AUC from 0.60 to 0.69 (p = 0.039). LGE + CS showed similar value as LGE + LDDSE. In the validation cohort, CS was also the strongest CMR-FT predictor of recovery and addition of CS to LGE improved overall accuracy to 73% although this difference was not significant (AUC 0.69, p = 0.44). Conclusion: CS is the strongest CMR-FT predictor of segmental functional recovery after STEMI. Its incremental value to LGE is comparable to that of LDDSE whilst avoiding an inotropic stress agent. CS is especially relevant in segments with 50-74% LGE where accuracy is lower and further testing is frequently required to clarify the potential for recovery.

Automatic left ventricle volume calculation with explainability through a deep learning weak-supervision methodology.

BACKGROUND AND OBJECTIVE: Magnetic resonance imaging is the most reliable imaging technique to assess the heart. More specifically there is great importance in the analysis of the left ventricle, as the main pathologies directly affect this region. In order to characterize the left ventricle, it is necessary to extract its volume. In this work we present a neural network architecture that is capable of directly estimating the left ventricle volume in short axis cine Magnetic Resonance Imaging in the end-diastolic frame and provide a segmentation of the region which is the basis of the volume calculation, thus offering explainability to the estimated value. METHODS: The network was designed to directly target the volumes to estimate, not requiring any labeled segmentation on the images. The network was based on a 3D U-net with extra layers defined in a scanning module that learned features like the circularity of the objects and the volumes to estimate in a weakly-supervised manner. The only targets defined were the left ventricle volumes and the circularity of the object detected through the estimation of the π value derived from its shape. We had access to 397 cases corresponding to 397 different subjects. We randomly selected 98 cases to use as test set. RESULTS: The results show a good match between the real and estimated volumes in the test set, with a mean relative error of 8% and a mean absolute error of 9.12 ml with a Pearson correlation coefficient of 0.95. The derived segmentations obtained by the network achieved Dice coefficients with a mean value of 0.79. CONCLUSIONS: The proposed method is capable of obtaining the left ventricle volume biomarker in the end-diastole and offer an explanation of how it obtains the result in the form of a segmentation mask without the need of segmentation labels to train the algorithm, making it a potentially more trustworthy method for clinicians and a way to train neural networks more easily when segmentation labels are not readily available.

Sex differences in mortality in stable patients undergoing vasodilator stress cardiovascular magnetic resonance.

OBJECTIVE: We assessed the influence of the ischaemic burden (IB) as derived from vasodilator stress cardiovascular magnetic resonance (CMR) on the risk of death and the effect of revascularisation across sex. METHODS: We evaluated 6237 consecutive patients with known or suspected chronic coronary syndrome (CCS). Extensive ischaemia was defined as >5 segments with perfusion deficit. Multivariate Cox proportional hazard regression models were used. RESULTS: A total of 2371 (38.0%) patients were women and 583 (9.3%) underwent CMR-related revascularisation. During a median follow-up of 5.13 years, 687 (11.0%) deaths were reported. We found an adjusted differential effect of CMR-derived IB across sex (p value for interaction=0.039). Women exhibited an adjusted lower risk of death and only equaled men's risk when extensive ischaemia was present. Likewise, CMR-related revascularisation was shown to be differentially associated with the risk of mortality across sex (p value for interaction=0.025). In patients with non-extensive ischaemia, revascularisation was associated with a higher risk of death, with a greater extent in women. At higher IB, revascularisation was associated with a lower risk in men, with more uncertain results in women. CONCLUSIONS: CMR-derived IB allows predicting the risk of death and gives insight into the potential effect of revascularisation in men and women with CCS. Compared with men, women with non-extensive ischaemia displayed a lower risk and a similar risk with a higher IB. The impact of CMR-related revascularisation on mortality risk was also significantly different according to IB and sex. Further research will be needed to confirm these hypothesis-generating findings.

Sex differences on new-onset heart failure in patients with known or suspected coronary artery disease.

AIMS: The impact of sex in patients with CAD has been widely reported, but little is known about the influence of sex on the risk of new-onset HF in patients with known or suspected CAD. We aimed to examine sex-related differences and new-onset heart failure (HF) risk in patients with known or suspected coronary artery disease (CAD) undergoing vasodilator stress cardiac magnetic resonance (CMR). METHODS AND RESULTS: We prospectively evaluated 5899 consecutive HF-free patients submitted to stress CMR for known or suspected CAD. Ischaemic burden (number of segments with stress-induced perfusion deficit) and left ventricular ejection fraction (LVEF) were assessed by CMR. The association between sex and new-onset HF (including outpatient diagnosis or acute HF hospitalization) was evaluated using a Cox proportional hazards regression model adjusted for competing events [death, myocardial infarction (MI), and revascularization]. A total of 2289 (38.8%) patients were women. During a median follow-up of 4.5 years, 610 (10.3%) patients died, 191 (3.2%) suffered an MI, 905 (15.3%) underwent revascularization, and 314 (5.3%) developed new-onset HF. Unadjusted new-onset HF rates were higher in women than in men (1.25 vs. 0.83 per 100 person-years, P = 0.001). After comprehensive multivariate adjustment, women showed an increased risk of new-onset HF (hazard ratio 1.58, 95% confidence interval 1.18-2.10; P = 0.002). We found a sex-differential effect along the continuum of LVEF (P-value for interaction = 0.007). At lower LVEF, there was an increased risk in both sexes. However, compared with men, the risk of new-onset HF was higher in women with LVEF >55%. CONCLUSION: Women with known or suspected CAD are at a higher risk of new-onset HF. Further studies are needed to unravel the mechanisms behind these sex-related differences.