The Incidence and Impact of Permanent Right Ventricular Infarction on Left Ventricular Infarct Size in Patients With Inferior ST-Segment Elevation Myocardial Infarction.

Mounting evidence shows that right ventricle (RV) function carries independent prognostic influence in various disease states. This study aimed to investigate the incidence and impact of permanent RV infarction in patients with inferior ST-segment elevation myocardial infarction (STEMI) and culprit lesion in the right coronary artery (RCA). In this substudy of the DANAMI-3 (DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction) trial, cardiac magnetic resonance was performed in 291 patients at day 1 and follow-up 3 months after primary percutaneous coronary intervention of 674 patients with STEMI with the culprit lesion in the RCA. Final infarct was assessed using late gadolinium enhancement on cardiac magnetic resonance at 3 months. Patients with permanent RV infarction (20%) had lower ventricular function at follow-up; RV ejection fraction (EF) 47% ±6 versus 50% ± 5 (p <0.005) and left ventricular (LV) EF 56% ± 8 versus 60% ± 9 (p <0.006). Furthermore, patients with permanent RV infarction had a higher incidence of microvascular obstruction 39 (67%) versus 81 (39%) (p <0.001), larger final LV infarct size 16% ±8 versus 10% ± 8 (p <0.001) and larger LV area at risk 33% ± 10 versus 29% ± 9 (p <0.001). Permanent RV infarction was an independent predictor of final LV infarct size (p <0.001) but was not associated with LVEF (ß = -0.0; p = 0.13) in multivariable analyses. In conclusion, permanent RV infarction was seen in 20% of patients with inferior STEMI and culprit lesion in RCA and independently predicted final LV infarct size. However, permanent RV infarction did not predict overall LV function. LGE was used to detect infarct location and quantify infarct size.17 LGE in RV free wall on follow-up CMR was considered as permanent infarction. LGE images were obtained 10 minutes after intravenous injection of 0.1-mmol/kg body weight of gadolinium-based contrast (Gadovist; Bayer Schering, Berlin, Germany) using an electrocardiogram (ECG)-triggered inversion-recovery sequence. The inversion time was adjusted to null the signal from the normal myocardium. Short-axis images were acquired from the atrioventricular plane to the apex with adjacent 8-mm slices. The remaining protocol has been described previously.16.

Cardiovascular magnetic resonance characteristics and clinical outcomes of patients with ST-elevation myocardial infarction and no standard modifiable risk factors-A DANAMI-3 substudy.

Introduction: A higher 30-day mortality has been observed in patients with first-presentation ST elevation myocardial infarction (STEMI) who have no standard modifiable cardiovascular risk factors (SMuRFs), i. e., diabetes, hypertension, hyperlipidemia, and current smoker. In this study, we evaluate the clinical outcomes and CMR imaging characteristics of patients with and without SMuRFs who presented with first-presentation STEMI. Methods: Patients from the Third DANish Study of Acute Treatment of Patients With ST-Segment Elevation Myocardial Infarction (DANAMI-3) with first-presentation STEMI were classified into those with no SMuRFs vs. those with at least one SMuRF. Results: We identified 2,046 patients; 283 (14%) SMuRFless and 1,763 (86%) had >0 SMuRF. SMuRFless patients were older (66 vs. 61 years, p < 0.001) with more males (84 vs. 74%, p < 0.001), more likely to have left anterior descending artery (LAD) as the culprit artery (50 vs. 42%, p = 0.009), and poor pre-PCI (percutaneous coronary intervention) TIMI (thrombolysis in myocardial infarction) flow ≤1 (78 vs. 64%; p < 0.001). There was no difference in all-cause mortality, non-fatal reinfarction, or hospitalization for heart failure at 30 days or at long-term follow-up. CMR imaging was performed on 726 patients. SMuRFless patients had larger acute infarct size (17 vs. 13%, p = 0.04) and a smaller myocardial salvage index (42 vs. 50%, p = 0.02). These differences were attenuated when the higher LAD predominance and/or TIMI 0-1 flow were included in the model. Conclusion: Despite no difference in 30-day mortality, SMuRFless patients had a larger infarct size and a smaller myocardial salvage index following first-presentation STEMI. This association was mediated by a larger proportion of LAD culprits and poor TIMI flow pre-PCI. Clinical trial registration: clinicaltrials.gov, unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER) and NCT01960933 (DANAMI 3-PRIMULTI).

Angiographic outcome in patients treated with deferred stenting after ST-segment elevation myocardial infarction-results from DANAMI-3-DEFER.

AIMS: Stent implantation during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) occasionally results in flow disturbances and distal embolization, which may cause adverse clinical outcomes. Deferred stent implantation seems to reduce the impairment on myocardial function, although the mechanisms have not been clarified. We sought to evaluate whether deferred stenting could reduce flow disturbance in patients treated with primary PCI. METHODS AND RESULTS: Patients with STEMI included in the DANAMI-3-DEFER trial were randomized to deferred versus immediate stent implantation. The primary and secondary outcomes of this substudy were the incidences of slow/no reflow and distal embolization. A total of 1205 patients were included. Deferred stenting (n = 594) resulted in lower incidences of distal embolization [odds ratio (OR) 0.67, 95% confidence interval (CI) 0.46-0.98, P = 0.040] and slow/no reflow (OR 0.60, 95%CI 0.37-0.97, P = 0.039). In high-risk subgroups, the protective effect was greatest in patients >65 years of age (slow/no reflow: OR 0.36, 95% CI 0.17-0.72, P = 0.004 and distal embolization: OR 0.34, 95% CI 0.18-0.63, P = 0.001), in patients presenting with occluded culprit artery at admission (slow/no reflow: OR 0.33, 95% CI 0.16-0.65, P = 0.001 and distal embolization: OR 0.54, 95% CI 0.31-0.96, P = 0.036) and in patients with thrombus grade >3 (slow/no reflow: OR 0.37, 95% CI 0.20-0.67, P = 0.001 and distal embolization: OR 0.39, 95% CI 0.24-0.64, P < 0.001) with a significant P for interaction for all. CONCLUSION: Deferred stent implantation reduces the incidences of slow/no reflow and distal embolization, especially in older patients and in those with total coronary occlusion or high level of thrombus burden.

Microcirculatory Function in Nonhypertrophic and Hypertrophic Myocardium in Patients With Aortic Valve Stenosis.

Background Left ventricular hypertrophy (LVH) has often been supposed to be associated with abnormal myocardial blood flow and resistance. The aim of this study was to evaluate and quantify the physiological and pathological changes in myocardial blood flow and microcirculatory resistance in patients with and without LVH attributable to severe aortic stenosis. Methods and Results Absolute coronary blood flow and microvascular resistance were measured using a novel technique with continuous thermodilution and infusion of saline. In addition, myocardial mass was assessed with cardiac magnetic resonance imaging. Fifty-three patients with aortic valve stenosis were enrolled in the study. In 32 patients with LVH, hyperemic blood flow per gram of tissue was significantly decreased compared with 21 patients without LVH (1.26±0.48 versus 1.66±0.65 mL·min-1·g-1; P=0.018), whereas minimal resistance indexed for left ventricular mass was significantly increased in patients with LVH (63 [47-82] versus 43 [35-63] Wood Units·kg; P=0.014). Conclusions Patients with LVH attributable to severe aortic stenosis had lower hyperemic blood flow per gram of myocardium and higher minimal myocardial resistance compared with patients without LVH.

Clinical outcomes of no stenting in patients with ST-segment elevation myocardial infarction undergoing deferred primary percutaneous coronary intervention.

BACKGROUND: ST-segment elevation myocardial infarction (STEMI) is treated with stenting, but the underlying stenosis is often not severe, and stenting may potentially be omitted. AIMS: The aim of the study was to investigate outcomes of patients with STEMI treated with percutaneous coronary intervention (PCI) without stenting. METHODS: Patients were identified through the DANAMI-3-DEFER study. Stenting was omitted in the patients with stable flow after initial PCI and no significant residual stenosis on the deferral procedure, who were randomised to deferred stenting. These patients were compared to patients randomised to conventional PCI treated with immediate stenting. The primary endpoint was a composite of all-cause mortality, recurrent myocardial infarction (MI), and target vessel revascularisation (TVR). RESULTS: Of 603 patients randomised to deferred stenting, 84 were treated without stenting, and in patients randomised to conventional PCI (n=612), 590 were treated with immediate stenting. Patients treated with no stenting had a median stenosis of 40%, median vessel diameter of 2.9 mm, and median lesion length of 11.4 mm. During a median follow-up of 3.4 years, the composite endpoint occurred in 14% and 16% in the no and immediate stenting groups, respectively (unadjusted hazard ratio [HR] 0.87, 95% confidence interval [CI]: 0.48-1.60; p=0.66). The association remained non-significant after adjusting for confounders (adjusted HR 0.53, 95% CI: 0.22-1.24; p=0.14). The rates of TVR and recurrent MI were 2% vs 4% (p=0.70) and 4% vs 6% (p=0.43), respectively. CONCLUSIONS: Patients with STEMI, with no significant residual stenosis and stable flow after initial PCI, treated without stenting, had comparable event rates to patients treated with immediate stenting.

Long-Term Changes in Invasive Physiological Pressure Indices of Stenosis Severity Following Transcatheter Aortic Valve Implantation.

BACKGROUND: Patients with severe aortic stenosis frequently have coexisting coronary artery disease. Invasive hyperemic and nonhyperemic pressure indices are used to assess coronary artery disease severity but have not been evaluated in the context of severe aortic stenosis. METHODS: We compared lesion reclassification rates of fractional flow reserve (FFR) and resting full-cycle ratio (RFR) measured before and 6 months after transcatheter aortic valve implantation using the conventional clinical cutoffs of ≤0.80 for FFR and ≤0.89 for RFR. This was a substudy of the ongoing NOTION-3 trial (Third Nordic Aortic Valve Intervention). Two-dimensional quantitative coronary analysis was used to assess changes in angiographic lesion severity. RESULTS: Forty patients were included contributing 50 lesions in which FFR was measured. In 32 patients (36 lesions), RFR was also measured. There was no significant change in diameter stenosis from baseline to follow-up, 49.8% (42.9%-57.1%) versus 52.3% (43.2%-57.8%), P=0.50. RFR improved significantly from 0.88 (0.83%-0.93) at baseline to 0.92 (0.83-0.95) at follow-up, P=0.003, whereas FFR remained unchanged, 0.84 (0.81-0.89) versus 0.86 (0.78-0.90), P=0.72. At baseline, 11 out of 50 (22%) lesions were FFR-positive, whereas 15 out of 50 (30%) were positive at follow-up, P=0.219. Corresponding numbers for RFR were 23 out of 36 (64%) at baseline and 12 out of 36 (33%) at follow-up, P=0.003. CONCLUSIONS: In patients with severe aortic stenosis, physiological assessment of coronary lesions with FFR before transcatheter aortic valve implantation leads to lower reclassification rate at 6-month follow-up, compared with RFR.

Combined In-silico and Machine Learning Approaches Toward Predicting Arrhythmic Risk in Post-infarction Patients.

Background: Remodeling due to myocardial infarction (MI) significantly increases patient arrhythmic risk. Simulations using patient-specific models have shown promise in predicting personalized risk for arrhythmia. However, these are computationally- and time- intensive, hindering translation to clinical practice. Classical machine learning (ML) algorithms (such as K-nearest neighbors, Gaussian support vector machines, and decision trees) as well as neural network techniques, shown to increase prediction accuracy, can be used to predict occurrence of arrhythmia as predicted by simulations based solely on infarct and ventricular geometry. We present an initial combined image-based patient-specific in silico and machine learning methodology to assess risk for dangerous arrhythmia in post-infarct patients. Furthermore, we aim to demonstrate that simulation-supported data augmentation improves prediction models, combining patient data, computational simulation, and advanced statistical modeling, improving overall accuracy for arrhythmia risk assessment. Methods: MRI-based computational models were constructed from 30 patients 5 days post-MI (the "baseline" population). In order to assess the utility biophysical model-supported data augmentation for improving arrhythmia prediction, we augmented the virtual baseline patient population. Each patient ventricular and ischemic geometry in the baseline population was used to create a subfamily of geometric models, resulting in an expanded set of patient models (the "augmented" population). Arrhythmia induction was attempted via programmed stimulation at 17 sites for each virtual patient corresponding to AHA LV segments and simulation outcome, "arrhythmia," or "no-arrhythmia," were used as ground truth for subsequent statistical prediction (machine learning, ML) models. For each patient geometric model, we measured and used choice data features: the myocardial volume and ischemic volume, as well as the segment-specific myocardial volume and ischemia percentage, as input to ML algorithms. For classical ML techniques (ML), we trained k-nearest neighbors, support vector machine, logistic regression, xgboost, and decision tree models to predict the simulation outcome from these geometric features alone. To explore neural network ML techniques, we trained both a three - and a four-hidden layer multilayer perceptron feed forward neural networks (NN), again predicting simulation outcomes from these geometric features alone. ML and NN models were trained on 70% of randomly selected segments and the remaining 30% was used for validation for both baseline and augmented populations. Results: Stimulation in the baseline population (30 patient models) resulted in reentry in 21.8% of sites tested; in the augmented population (129 total patient models) reentry occurred in 13.0% of sites tested. ML and NN models ranged in mean accuracy from 0.83 to 0.86 for the baseline population, improving to 0.88 to 0.89 in all cases. Conclusion: Machine learning techniques, combined with patient-specific, image-based computational simulations, can provide key clinical insights with high accuracy rapidly and efficiently. In the case of sparse or missing patient data, simulation-supported data augmentation can be employed to further improve predictive results for patient benefit. This work paves the way for using data-driven simulations for prediction of dangerous arrhythmia in MI patients.

Ischemia From Nonculprit Stenoses Is Not Associated With Reduced Culprit Infarct Size in Patients with ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: In patients with ST-segment-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention, reperfusion injury accounts for a significant fraction of the final infarct size, which is directly related to patient prognosis. In animal studies, brief periods of ischemia in noninfarct-related (nonculprit) coronary arteries protect the culprit myocardium via remote ischemic preconditioning. Positive fractional flow reserve (FFR) documents functional significant coronary nonculprit stenosis, which may offer remote ischemic preconditioning of the culprit myocardium. The aim of the study was to investigate the association between functional significant, multivessel disease (MVD) and reduced culprit final infarct size or increased myocardial salvage (myocardial salvage index [MSI]) in a large contemporary cohort of STEMI patients. METHODS: Cardiac magnetic resonance was performed in 610 patients with STEMI at day 1 and 3 months after primary percutaneous coronary intervention. Patients were stratified into 3 groups according to FFR measurements in nonculprit stenosis (if any): angiographic single vessel disease (SVD), FFR nonsignificant MVD (functional SVD), or FFR-significant, functional MVD. RESULTS: A total of 431 (71%) patients had SVD, 35 (6%) had functional SVD, and 144 (23%) had functional MVD. There was no difference in final infarct size (mean infarct size [%left ventricular mass] SVD, 9±3%; functional SVD, 9±3%; and functional MVD, 9±3% [P=0.82]) or in MSI between groups (mean MSI [%left] SVD, 66±23%; functional SVD, 68±19%; and functional MVD, 69±19% [P=0.62]). In multivariable analyses, functional MVD was not associated with larger MSI (P=0.56) or smaller infarct size (P=0.55). CONCLUSIONS: Functional MVD in nonculprit myocardium was not associated with reduced culprit final infarct size or increased MSI following STEMI. This is important knowledge for future studies examining a cardioprotective treatment in patients with STEMI, as a possible confounding effect of FFR-significant, functional MVD can be discarded. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER) and NCT01960933 (DANAMI 3-PRIMULTI).

Impact of age on reperfusion success and long-term prognosis in ST-segment elevation myocardial infarction - A cardiac magnetic resonance imaging study.

BACKGROUND: Coronary collateral circulation and conditioning from remote ischemic coronary territories may protect culprit myocardium in the elderly, and younger STEMI patients could suffer from larger infarcts. We evaluated the impact of age on myocardial salvage and long-term prognosis in a contemporary STEMI cohort. METHODS: Of 1603 included STEMI patients 807 underwent cardiac magnetic resonance. To assess the impact of age on infarct size and left ventricular ejection fraction (LVEF) as well as the composite endpoint of death and re-hospitalization for heart failure we stratified the patients by an age cut-off of 60 years. RESULTS: Younger STEMI patients had smaller final infarcts (10% vs. 12%, P = 0.012) and higher final LVEF (60% vs. 58%, P = 0.042). After adjusting for multiple potential confounders age did not remain significantly associated with infarct size and LVEF. During 4-year follow-up, the composite endpoint occurred less often in the young (3.2% vs. 17.2%; P < 0.001) with a univariate hazard ratio of 5.77 (95% CI, 3.75-8.89; p < 0.001). Event estimates of 4 subgroups (young vs. elderly and infarct size beyond vs. below median) showed a gradual increase in the occurrence of the composite endpoint depending on both age and acute infarct size (log-rank p < 0.001). CONCLUSION: Having a STEMI after entering the seventh decade of life more than quadrupled the risk of future death or re-hospitalization for heart failure. Risk of death and re-hospitalization depended on both advanced age and infarct size, albeit no substantial difference was found in infarct size, LVEF and salvage potential between younger and elderly patients with STEMI.

Usefulness of High Sensitivity Troponin T to Predict Long-Term Left Ventricular Dysfunction After ST-Elevation Myocardial Infarction.

Guidelines recommend the use of transthoracic echocardiography (TTE) and clinical scores to risk stratify patients after ST-elevation myocardial infarction (STEMI). High sensitivity troponin T (hs-cTnT) is predictive of outcome after STEMI but the predictive value of hs-cTnT relative to other risk assessment tools has not been established. We aimed to compare the predictive value of hs-cTnT to other risk assessment tools in patients with STEMI. A subset of 578 patients with STEMI were included in this post-hoc study from the Third DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction trial. Patients underwent cardiac magnetic resonance imaging (CMR) during index hospitalization as well as TTE at 1 year after their STEMI. The predictive value of hs-cTnT was compared with CKMB, infarct size (IS)/left ventricular ejection fraction (LVEF) assessed with CMR, LVEF assessed at discharge with TTE and the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis in Myocardial Infarction (TIMI) risk-scores. The primary outcome was LV systolic dysfunction defined as LVEF ≤40% after 1 year on TTE. The area under the receiver operating characteristic curve analyses showed no significant difference between hs-cTnT and early CMR-assessed IS or LVEF in predicting subsequent LVEF ≤40%. Area under the curve for hs-cTnT was 0.82, 0.85 for IS (p = 0.22), and 0.87 for LVEF (p = 0.23). For predischarge TTE-assessed LVEF, the value was 0.85 (p = 0.45), 0.63 for creatine kinase-MB (p <0.001), 0.61 for the GRACE score (p <0.001), and 0.70 for the TIMI score (p = 0.02). A peak hs-cTnT value <3,500 ng/L ruled out LVEF ≤40% with probability of 98%. In conclusion, in patients presenting with STEMI undergoing PCI, hs-cTnT level strongly predicted long-term LV dysfunction and could be used as a clinical risk stratification tool to identify patients at high risk of progressing to LV dysfunction due to its general availability and high-predictive accuracy.

Infarct size following loading with Ticagrelor/Prasugrel versus Clopidogrel in ST-segment elevation myocardial infarction.

BACKGROUND: Treatment with newer direct-acting anti-platelet drugs (Ticagrelor and Prasugrel) prior to primary percutaneous coronary intervention (PCI) is associated with improved outcome in patients with ST-segment elevation myocardial infarction (STEMI) when compared with Clopidogrel. We compared infarct size following treatment with Ticagrelor/Prasugrel versus Clopidogrel in the DANish trial in Acute Myocardial Infarction (DANAMI-3) population of STEMI patients treated with primary PCI. METHODS AND RESULTS: Patients were loaded with Clopidogrel, Ticagrelor or Prasugrel in the ambulance before primary PCI. Infarct size and myocardial salvage index were calculated using cardiac magnetic resonance (CMR) during index admission and at three-month follow-up. Six-hundred-and-ninety-three patients were included in this analysis. Clopidogrel was given to 351 patients and Ticagrelor/Prasugrel to 342 patients. The groups were generally comparable in terms of baseline and procedural characteristics. Median infarct size at three-month follow-up was 12.9% vs 10.0%, in patients treated with Clopidogrel and Ticagrelor/ Prasugrel respectively (p < 0.001), and myocardial salvage index was 66% vs 71% (p < 0.001). Results remained significant in a multiple regression model (p < 0.001). CONCLUSIONS: Pre-hospital loading with Ticagrelor or Prasugrel compared to Clopidogrel, was associated with smaller infarct size and larger myocardial salvage index at three-month follow-up in patients with STEMI treated with primary PCI.

Electrocardiogram to predict reperfusion success in late presenters with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention.

BACKGROUND: Clinical decision-making in patients with ST-segment elevation myocardial infarction (STEMI) presenting beyond 12 h of symptom onset (late presenters) is challenging. However, the electrocardiogram (ECG) may provide helpful information. We investigated the association between three ECG-scores and myocardial salvage and infarct size in late presenters treated with primary percutaneous coronary intervention (primary PCI). METHODS: Sixty-six patients with STEMI and ongoing symptoms presenting 12-72 h after symptom onset were included. Cardiac magnetic resonance was performed at day 1 (interquartile range [IQR], 1-1) and at follow-up at day 93 (IQR, 90-98). The pre-PCI ECG was analyzed for the presence of pathological QW (early QW) as well as Anderson-Wilkins acuteness score (AW-score), the classic Sclarovsky-Birnbaum Ischemia Grading System (classic SB-IG-score) and a modified SB-IG-score including any T-wave morphologies. RESULTS: Early QW was associated with a larger myocardium at risk (39 ± 12 versus 33 ± 12; p = 0.030) and final infarct size (20 ± 11 versus 14 ± 9; p = 0.021) as well as a numerical lower final myocardial salvage (0.52 ± 0.19 versus 0.61 ± 0.23; p = 0.09). The association with final infarct size disappeared after adjusting for myocardium at risk. An AW-score < 3 showed a trend towards a larger final infarct size (18 ± 11 versus 11 ± 11; p = 0.08) and was not associated with salvage index (0.55 ± 0.20 versus 0.65 ± 0.30; p = 0.23). The classic and modified SB-IG-score were not associated with final infarct size (modified SB-IG-score, 17 ± 10 versus 21 ± 13; p = 0.28) or final myocardial salvage (0.53 ± 0.20 versus 0.53 ± 0.26; p = 0.96). CONCLUSION: Of three well-established ECG-scores only early QW and AW-score < 3 showed association with myocardium at risk and infarct size to some extent, but the association with myocardial salvage was weak. Hence, neither of the three investigated ECG-scores are sufficient to guide clinical decision-making in patients with STEMI and ongoing symptoms presenting beyond 12 h of symptom onset.

Early Q-wave morphology in prediction of reperfusion success in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention - A cardiac magnetic resonance imaging study.

BACKGROUND: Pathological Q-wave (QW) in the electrocardiogram (ECG) before primary percutaneous coronary intervention (primary PCI) is a strong prognostic marker in patients with ST-segment elevation myocardial infarction (STEMI). However, current binary QW criteria are either not clinically applicable or have a lack of diagnostic performance. Accordingly, we evaluated the association between duration, depth and area of QW and markers of the effect of reperfusion (reperfusion success). METHODS: A total of 516 patients with their first STEMI had obtained an ECG before primary PCI and an acute cardiac magnetic resonance imaging (CMR) at day 1 (interquartile range [IQR], 1-1) and at follow-up at day 92 (IQR, 89-96). The largest measurable QW in ECG was used for analysis of duration, depth and area of QW (QW morphology). The QW morphology was evaluated as a continuous variable in linear regression models and as a variable divided in four equally large groups. RESULTS: The QW morphology as four equally large groups was significantly associated with all CMR endpoints (p ≤ 0.001) and showed a linear relationship (p ≤ 0.001) with final infarct size (for QW duration, ß = 0.47; QW depth, ß = 0.41 and QW area, ß = 0.39), final infarct transmurality (for QW duration, ß = 0.36; QW depth, ß = 0.26 and QW area, ß = 0.23) and final myocardial salvage index (for QW duration, ß = -0.34; QW depth, ß = -0.26 and QW area, ß = -0.24). CONCLUSION: Although modest, the QW morphology in STEMI patients showed significant linear association with markers of reperfusion success. Hence, it is suggested that the term pathological is not used as a dichotomous parameter in patients with STEMI but rather evaluated on the basis of extent.

Fractional flow reserve-guided PCI in patients with and without left ventricular hypertrophy: a DANAMI-3-PRIMULTI substudy.

AIMS: The aim of this substudy was to investigate the correlation between fractional flow reserve (FFR) and diameter stenosis in patients with STEMI with and without left ventricular hypertrophy (LVH), and the influence of LVH on complete FFR-guided revascularisation versus culprit only, in terms of risk of clinical outcome. METHODS AND RESULTS: In this DANAMI-3-PRIMULTI substudy, 279 patients with STEMI had cardiac magnetic resonance (CMR) imaging for assessment of left ventricular mass index. Ninety-six patients had FFR evaluation of a non-culprit lesion. Diameter stenosis of the non-culprit lesion was determined with two-dimensional quantitative coronary analysis. The diameter stenosis (56.9% vs 54.3%, p=0.38) and FFR value (0.83 vs 0.85, p=0.34) were significantly correlated in both groups (Spearman's ρ=-0.40 and -0.41 without LVH and with LVH, respectively; p<0.001) but were not different between patients without and with LVH (p for interaction=0.87). FFR-guided complete revascularisation was associated with reduced risk of death, myocardial infarction or ischaemia-driven revascularisation both for patients without LVH (HR 0.42, 95% CI: 0.20-0.85) and for patients with LVH (HR 0.50, 95% CI: 0.17-1.47), with no interaction between the FFR-guided complete revascularisation and LVH (p for interaction=0.82). CONCLUSIONS: LVH did not interact with the correlation between diameter stenosis and FFR and did not modify the impact of complete revascularisation on the occurrence of subsequent clinical events.

Sub-acute cardiac magnetic resonance to predict irreversible reduction in left ventricular ejection fraction after ST-segment elevation myocardial infarction: A DANAMI-3 sub-study.

AIMS: To predict irreversible reduction in left ventricular ejection fraction (LVEF) during admission for ST-segment elevation myocardial infarction (STEMI) using cardiac magnetic resonance (CMR) in addition to classical clinical parameters. Irreversible reduction in LVEF is an important prognostic factor after STEMI which necessitates medical therapy and implantation of prophylactic implantable cardioverter defibrillator (ICD). METHODS AND RESULTS: A post-hoc analysis of DANAMI-3 trial program (Third DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction) which recruited 649 patients who had CMR performed during index hospitalization and after 3 months. Patients were divided into two groups according to CMR-LVEF at 3 months: Group 1 with LVEF≤35% and Group 2 with LVEF>35%. Group 1 included 15 patients (2.3%) while Group 2 included 634 patients (97.7%). A multivariate analysis showed that: Killip class >1 (OR 7.39; CI:1.47-36.21, P = 0.01), symptom onset-to-wire ≥6 h (OR 7.19; CI 1.07-50.91, P = 0.04), LVEF≤35% using index echocardiography (OR 7.11; CI: 1.27-47.43, P = 0.03), and infarct size ≥40% of LV on index CMR (OR 42.62; CI:7.83-328.29, P < 0.001) independently correlated with a final LVEF≤35%. Clinical models consisted of these parameters could identify 7 out of 15 patients in Group 1 with 100% positive predictive value. CONCLUSION: Together with other clinical measurements, the assessment of infarct size using late Gadolinium enhancement by CMR during hospitalization is a strong predictor of irreversible reduction in CMR_LVEF ≤35. That could potentially, after validation with future research, aids the selection and treatment of high-risk patients after STEMI, including implantation of prophylactic ICD during index hospitalization.

Complete Revascularization Versus Culprit Lesion Only in Patients With ST-Segment Elevation Myocardial Infarction and Multivessel Disease: A DANAMI-3-PRIMULTI Cardiac Magnetic Resonance Substudy.

OBJECTIVES: The aim of this study was to evaluate the effect of fractional flow reserve (FFR)-guided revascularization compared with culprit-only percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) on infarct size, left ventricular (LV), function, LV remodeling, and the presence of nonculprit infarctions. BACKGROUND: Patients with STEMI with multivessel disease might have improved clinical outcomes after complete revascularization compared with PCI of the infarct-related artery only, but the impact on infarct size, LV function, and remodeling as well as the risk for periprocedural infarction are unknown. METHODS: In this substudy of the DANAMI-3 (Third Danish Trial in Acute Myocardial Infarction)-PRIMULTI (Primary PCI in Patients With ST-Elevation Myocardial Infarction and Multivessel Disease: Treatment of Culprit Lesion Only or Complete Revascularization) randomized trial, patients with STEMI with multivessel disease were randomized to receive either complete FFR-guided revascularization or PCI of the culprit vessel only. The patients underwent cardiac magnetic resonance imaging during index admission and at 3-month follow-up. RESULTS: A total of 280 patients (136 patients with infarct-related and 144 with complete FFR-guided revascularization) were included. There were no differences in final infarct size (median 12% [interquartile range: 5% to 19%] vs. 11% [interquartile range: 4% to 18%]; p = 0.62), myocardial salvage index (median 0.71 [interquartile range: 0.54 to 0.89] vs. 0.66 [interquartile range: 0.55 to 0.87]; p = 0.49), LV ejection fraction (mean 58 ± 9% vs. 59 ± 9%; p = 0.39), and LV end-systolic volume remodeling (mean 7 ± 22 ml vs. 7 ± 19 ml; p = 0.63). New nonculprit infarction occurring after the nonculprit intervention was numerically more frequent among patients treated with complete revascularization (6 [4.5%] vs. 1 [0.8%]; p = 0.12). CONCLUSIONS: Complete FFR-guided revascularization in patients with STEMI and multivessel disease did not affect final infarct size, LV function, or remodeling compared with culprit-only PCI.

Impact of Multiple Myocardial Scars Detected by CMR in Patients Following STEMI.

OBJECTIVES: This study investigated the incidence and long-term prognostic importance of multiple myocardial scars in cardiac magnetic resonance (CMR) in a large contemporary cohort of patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Patients presenting with STEMI may have multiple infarctions/scars caused by multiple culprit lesions, previous myocardial infarction (MI) or procedure-related MI due to nonculprit interventions. However, the incidence, long-term prognosis, and distribution of causes of multiple myocardial scars remain unknown. METHODS: CMR was performed in 704 patients with STEMI 1 day after primary percutaneous coronary intervention (PCI) and again 3 months later. Myocardial scars were assessed by late gadolinium enhancement (LGE). T2-weighted technique was used to differentiate acute from chronic infarctions. The presence of multiple scars was defined as scars located in different coronary territories. The combined endpoints of all-cause mortality and hospitalization for heart failure were assessed at 39 months (interquartile range [IQR]: 31 to 48 months). RESULTS: At 3 months, 59 patients (8.4%) had multiple scars. Of these, multiple culprits in STEMI were detected in 7 patients (1%), and development of a second nonculprit scar at follow-up occurred in 10 patients (1.4%). The most frequent cause of multiple scars was a chronic scar in the nonculprit myocardium. The presence of multiple scars was independently associated with an increased risk of all-cause mortality and hospitalization for heart failure (hazard ratio: 2.7; 95% confidence interval: 1.1 to 6.8; p = 0.037). CONCLUSIONS: Multiple scars were present in 8.4% of patients with STEMI and were independently associated with an increased risk of long-term morbidity and mortality. The presence of multiple myocardial scars on CMR may serve as a useful tool in risk stratification of patients following STEMI. (DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction [DANAMI-3]; NCT01435408) (Primary PCI in Patients With ST-elevation Myocardial Infarction and Multivessel Disease: Treatment of Culprit Lesion Only or Complete Revascularization [PRIMULTI]; NCT01960933).

Assessment of the myocardial area at risk: comparing T2-weighted cardiovascular magnetic resonance imaging with contrast-enhanced cine (CE-SSFP) imaging-a DANAMI3 substudy.

AIMS: Myocardial salvage following treatment for ST-segment elevation myocardial infarction is prognostic for morbidity and mortality. Studies with myocardial salvage as endpoint rely on valid assessment of the myocardial area at risk (AAR). T2-weighted cardiovascular magnetic resonance (CMR) imaging is the preferred method to assess the AAR. However, T2-weighted imaging can be of poor image quality and uninterpretable. Contrast-enhanced (CE) cine imaging can also show AAR and our aim was to investigate if CE-cine can replace T2-weighted imaging. Cine imaging is part of a standard CMR-protocol and implementing CE-cine imaging for assessment of the AAR would mean shorter investigation time. METHODS AND RESULTS: As a DANAMI-3 substudy, we performed successful dual imaging of the AAR in 166 participants using both T2-weighted short tau inversion recovery (T2-STIR) and CE-cine imaging. T2-STIR imaging was non-diagnostic in nine and CE-cine in one scan during the period. CE-cine measured 4.7% of left ventricle (LV) [95% confidence interval 3.2-6.2%] smaller AAR compared with T2-STIR images (P < 0.001). Visual analysis of a plot of infarct size vs. AAR showed an overestimation of the AAR when measured with T2-STIR images. There was no difference in AAR with CE-cine in an interobserver analysis of 46 scans [1.2 g (standard deviation 9.5), P = 0.42]. CONCLUSIONS: CE-cine imaging shows good internal consistency in assessment of the AAR. A visual inspection reveals possible overestimation of AAR with T2-STIR images. There is good interobserver agreement in the analysis of CE-cine imaging. CE-cine can replace T2-STIR imaging resulting in a more valid assessment of the myocardial AAR.

Importance of elevated heart rate in the very early phase of ST-segment elevation myocardial infarction: Results from the DANAMI-3 trial.

BACKGROUND: Elevated heart rate is associated with poor clinical outcome in patients with acute myocardial infarction. However, in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention the importance of elevated heart rate in the very early phase remains unknown. We evaluated the impact of elevated heart rate in the very early pre-hospital phase of ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention on cardiovascular magnetic resonance markers of reperfusion success and clinical outcome. METHODS: In this DANAMI-3 substudy, 1560 ST-segment elevation myocardial infarction patients in sinus rhythm without cardiogenic shock were included in the analyses of clinical outcome and 796 patients underwent cardiovascular magnetic resonance to evaluate area at risk, infarct size and left ventricular ejection fraction. Heart rate was assessed on the first electrocardiogram with ST-elevation (time of diagnosis). RESULTS: Despite equal area at risk (33%±11 versus 36%±16, p=0.174) patients with a pre-hospital heart rate ⩾100 beats per minute developed larger infarcts (19% (interquartile range, 9-17) versus 11% (interquartile range, 10-28), p=0.001) and a lower left ventricular ejection fraction (54%±12 versus 58%±9, p=0.047). Pre-hospital heart rate ⩾100 beats per minute was independently associated with an increased risk of all-cause mortality and heart failure (hazard ratio 2.39 (95% confidence interval 1.58-3.62), p<0.001). CONCLUSIONS: Very early heart rate ⩾100 beats per minute in ST-segment elevation myocardial infarction was independently associated with larger infarct size, reduced left ventricular ejection fraction and an increased risk of all-cause mortality and heart failure, and thus serves as an easily obtainable and powerful tool to identify ST-segment elevation myocardial infarction patients at high risk.