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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.

Background: The impact of disease severity on the outcome after complete revascularization in patients with ST-segment-elevation myocardial infarction and multivessel disease is uncertain. The objective of this post hoc study was to evaluate the impact of number of diseased vessel, lesion location, and severity of the noninfarct-related stenosis on the effect of fractional flow reserve-guided complete revascularization., Methods and Results: In the DANAMI-3-PRIMULTI study (Primary PCI in Patients With ST-Elevation Myocardial Infarction and Multivessel Disease: Treatment of Culprit Lesion Only or Complete Revascularization), we randomized 627 ST-segment-elevation myocardial infarction patients to fractional flow reserve-guided complete revascularization or infarct-related percutaneous coronary intervention only. In patients with 3-vessel disease, fractional flow reserve-guided complete revascularization reduced the primary end point (all-cause mortality, reinfarction, and ischemia-driven revascularization; hazard ratio [HR], 0.33; 95% confidence interval [CI], 0.17-0.64; P =0.001), with no significant effect in patients with 2-vessel disease (HR, 0.77; 95% CI, 0.47-1.26; P =0.29; P for interaction =0.046). A similar effect was observed in patients with diameter stenosis ≥90% of noninfarct-related arteries (HR, 0.32; 95% CI, 0.18-0.62; P =0.001), but not in patients with less severe lesions (HR, 0.72; 95% CI, 0.44-1.19; P =0.21; P for interaction =0.06). The effect was most pronounced in patients with 3-vessel disease and noninfarct-related stenoses ≥90%, and in this subgroup, there was a nonsignificant reduction in the end point of mortality and reinfarction (HR, 0.32; 95% CI, 0.08-1.32; P =0.09). Proximal versus distal location did not influence the benefit from complete revascularization., Conclusions: The benefit from fractional flow reserve-guided complete revascularization in ST-segment-elevation myocardial infarction patients with multivessel disease was dependent on the presence of 3-vessel disease and noninfarct diameter stenosis ≥90% and was particularly pronounced in patients with both of these angiographic characteristics., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01960933., (© 2017 American Heart Association, Inc.)

Background: Pathological early Q waves (QW) are associated with adverse outcomes in patients with ST-segment-elevation myocardial infarction (STEMI). Primary percutaneous coronary intervention (PCI) may therefore be less beneficial in patients with QW than in patients without QW. Myocardial salvage index and microvascular obstruction (MVO) are markers for reperfusion success. Thus, to clarify the benefit from primary PCI in STEMI patients with QW, we examined the association between baseline QW and myocardial salvage index and MVO in STEMI patients treated with primary PCI., Methods and Results: The ECG was assessed before primary PCI for the presence of QW (early) in 515 STEMI patients. The patients underwent a cardiac magnetic resonance imaging scan at day 1 (interquartile range [IQR], 1-1) and again at day 92 (IQR, 89-96). Early QW was observed in 108 (21%) patients and was related to smaller final myocardial salvage index (0.59 [IQR, 0.39-0.69] versus 0.65 [IQR, 0.46-0.84]; P <0.001) and larger MVO (1.4 [IQR, 0.0-5.4] versus 0.0 [IQR, 0.0-2.4]; P <0.001) compared with non-QW. QW remained associated with both final myocardial salvage index (β=-0.12; P =0.03) and MVO (β=0.18; P =0.001) after adjusting for potential confounders., Conclusions: Patients presenting with their first STEMI and early QW in the ECG had smaller myocardial salvage index and more extensive MVO than non-QW despite treatment within 12 hours after symptom onset. However, final myocardial salvage index in patients with QW was substantial, and patients with QW still benefit from primary PCI., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01435408., (© 2017 American Heart Association, Inc.)

Some patients presenting with ST-segment elevation myocardial infarction (STEMI) have complete ST resolution in the electrocardiogram, which may be clinical useful in the triage of patients with STEMI. However, the importance of complete ST resolution in these patients remains uncertain. Thus, the purpose was to describe the prognosis of patients with complete ST resolution before primary percutaneous coronary intervention (PCI). Continuous ST monitoring from arrival until 90 minutes after PCI was performed in 933 patients with STEMI. Complete ST resolution was defined as no residual significant ST elevations before intervention. The patients were followed clinically for 5.5 years (range 0 to 6.8 years). Infarct size and myocardial salvage were assessed in a subgroup of patients (n = 221) by cardiovascular magnetic resonance. Complete ST resolution was observed in 24% of the patients, who had a higher incidence of Thrombolysis In Myocardial Infarction grade 2/3 flow before intervention (64% vs 24%), smaller infarct size (6% vs 11%), and higher myocardial salvage index (0.82 vs 0.69; all p <0.001) compared with patients with continuous ST elevations. Complete ST resolution was associated with a significantly lower rate of the composite end point of all-cause death and admission for heart failure (14% vs 22%; p = 0.006) although it only tended to be an independent predictor in a multivariate analysis (hazard ratio 0.69, 95% CI 0.49 to 1.06; p = 0.09). In conclusion, compared to patients without incomplete ST resolution, patients with STEMI and complete ST resolution before primary PCI have a higher incidence of normalized epicardial flow before PCI, a larger myocardial salvage and smaller infarct size after the procedure and presumably improved long-term outcome compared with incomplete ST resolution., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background and Aim: The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR., Method and Results: In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53)., Conclusion: The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aims: The left atrium (LA) transfers blood to the left ventricle in a complex manner. LA function is characterized by passive emptying (LA passive fraction), active emptying (LA ejection fraction), and total emptying (LA fractional change). Despite this complexity, the clinical relevance of the LA is based almost exclusively on LA maximal volume (LAmax), which may not glean the full prognostic potential. Cardiovascular magnetic resonance (CMR) is considered the most accurate method for studying LA function and size. The aim of the present study was to evaluate the prognostic importance of LA function in patients following ST elevation myocardial infarction (STEMI)., Methods and Results: In 199 patients, a CMR scan was performed within 1-3 days after STEMI to measure LAmax and minimal volume (LAmin) and LA function. The incidence of death, re-infarction, stroke, and admission for heart failure [major adverse cardiac event (MACE)] were registered during the follow-up period [2.3 years (inter-quartile range: 2.0-2.5)]. A total of 40 patients (20%) met the clinical endpoint of MACE during follow-up. In a Cox regression analysis adjusting for known risk factors, LA fractional change remained independently associated with MACE [adjusted hazard ratio: 0.66 (95% confidence interval: 0.46-0.95)]. LAmax, LAmin, or LA passive fraction was not independently associated with MACE. Furthermore, LA fractional change provided incremental prognostic value to LAmax and other known predictors (Wald χ(2) 31.0 vs. 39.9, P= 0.016)., Conclusion: In STEMI patients, impaired LA fractional change is independently associated with outcome and provide incremental prognostic information to established predictors including LAmax.

Background and Purpose: One third of patients treated with primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction develop a secondary increase in electrocardiographic ST segment (ST peak) during reperfusion. The purpose was to determine the clinical importance of ST peak during primary PCI., Methods: A total of 363 patients with ST-elevation myocardial infarction were stratified to no ST peak or ST peak. Final infarct size and ejection fraction (EF) were assessed by cardiovascular magnetic resonance., Results: Patients with ST peak had a larger infarct size (14% vs 10%; P = .003) and lower EF (53% vs 57%; P = .022). Rates of cardiac mortality (8% vs 3%; P = .047) and cardiac events (cardiac mortality and admission for heart failure; 19% vs 10%; P = .018) were higher among patients with ST peak, but not all-cause mortality (8% vs 5%; P = .46). In a multivariable Cox regression analysis, ST peak remained significantly associated with cardiac events (adjusted hazard ratio, 2.03 [1.08-3.82])., Conclusion: ST peak during primary PCI is related to larger final infarct size, a reduced EF, and adverse cardiac clinical outcome., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background and Purpose: Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates well with MI size determined by DE-MRI in reperfused STEMI., Methods and Results: The relationship was evaluated retrospectively in 55 first-time STEMI patients 3 months after receiving primary percutaneous coronary intervention. Selvester QRS score and DE-MRI MI size were significantly correlated, r = 0.41 (P < .01). The difference between the Selvester QRS score and DE-MRI was 5.8% MI of the left ventricle (95% confidence interval, 2.9%-8.6%). Furthermore, increasing difference between Selvester QRS score and DE-MRI was observed with increasing MI size., Conclusion: Selvester QRS score correlated only moderately with DE-MRI MI size. Selvester QRS score overestimated MI size., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Ischemic postconditioning (IPost) during primary percutaneous coronary intervention (PPCI) is suggested to reduce myocardial damage. However, the association with ST-segment resolution (STR) and clinical outcome is not determined. The primary aim of this study was to evaluate the association of IPost with STR and clinical outcome. Secondly, we sought to determine the relationship between STR and cardiac magnetic resonance (CMR) parameters in these patients., Methods: One hundred eighteen patients referred for PPCI were randomly assigned to either conventional PPCI or PPCI with IPost. In a single electrocardiographic lead, STR was determined. Treatment modalities were compared as regards STR, ST-segment elevation, and the number of patients achieving complete-STR (≥70%), incomplete-STR (30%-70%), and no-STR (<30%). Patients were evaluated for clinical outcome after 15 months. Furthermore, patients with and without complete-STR were compared as regards CMR parameters., Results: There was a tendency toward a better outcome with IPost for the number of patients achieving complete-STR (55% vs 63%; P=.09), ST-segment elevation (1.41 vs 1.12 mm; P=.07), and New York Heart Association class (P=.06). No difference in other cardiac events was observed. Furthermore, data determine that patients with complete-STR have smaller infarct size (12.9% vs 21.1%; P<.01) and a better ejection fraction (55.7% vs 47.7%; P<.01)., Conclusions: Patients treated with IPost are suggested to have improved STR and New York Heart Association classification. Infarct size and the functional CMR parameters were better in the patients with complete-STR; as to this, single-lead STR remains an important predictor for successful treatment in patients treated with IPost., (Copyright © 2010 Mosby, Inc. All rights reserved.)

Objectives: The purpose of this study was to evaluate the long-term effects of distal protection during percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI)., Background: The use of distal filter protection during primary PCI increases procedure complexity and may influence lesion treatment and stent implantation., Methods: The STEMI patients were assigned to distal protection (DP) (n = 312) or conventional treatment (CT) (n = 314). Clinical follow-up was performed after 1, 6, and 15 months, and angiographic follow-up after 8 months. All target lesion revascularizations (TLRs) were clinically driven. We report the pre-specified end points of stent thrombosis according to the criteria of the Academic Research Consortium, TLR, and reinfarction after 15 months., Results: The total number of stent thrombosis was 11 in the DP group and 4 in the CT group (p = 0.06). The rate of definite stent thrombosis was significantly increased in the DP group as compared with the CT group, with 9 cases versus 1 (p = 0.01). Clinically driven TLRs (31 patients vs. 18 patients, p = 0.05) and clinically driven target vessel revascularizations (37 patients vs. 22 patients, p = 0.04) were more frequent in the DP group., Conclusions: In primary PCI for STEMI, the routine use of DP increased the incidence of stent thrombosis and clinically driven target lesion/vessel revascularization during 15 months of follow-up. (Drug Elution and Distal Protection in ST Elevation Myocardial Infarction Trial [DEDICATION]; NCT00192868)., (Copyright 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background In patients with ST-segment elevation myocardial infarction (STEMI) pre-infarction angina, pre-procedural TIMI flow and collateral flow to the myocardium supplied by the infarct related artery are suggested to be cardioprotective. We evaluated the effect of these factors on myocardial salvage index (MSI) and infarct size adjusting for area at risk in patients with STEMI treated with primary percutaneous coronary intervention. Methods and Results Cardiac magnetic resonance (CMR) was used to measure myocardial area at risk within 1-7 days and final infarct size 90±21 days after the STEMI in 200 patients. MSI was calculated as (area-at-risk infarct size) / area-at-risk. Patients with pre-infarction angina had a median MSI of 0.80 (IQR 0.67 to 0.86) versus 0.72 (0.61 to 0.80) in those without pre-infarction angina, P = 0.004). In a regression analysis of the infarct size plotted against the area-at-risk there was a strong trend that the line for the pre-infarction angina group was below the one for the non-angina group (P = 0.05). Patients with pre-procedural TIMI flow 0/1, 2 and 3 had a median MSI of (0.69 (IQR 0.59 to 0.76), 0.78 (0.68 to 0.86) and 0.85 (0.77 to 0.91), respectively (P<0.001). Collateral flow did not change MSI (P = 0.45) nor area-at-risk (P = 0.40) and no significant difference in infarct size adjusted for area at risk (P = 0.25) was observed. Conclusions Pre-infarction angina increases MSI in patients with STEMI supporting the theory that pre-infarction angina leads to ischemic preconditioning. As opposed to the presence of angiographically visible collateral flow to the infarct area pre-procedural TIMI flow is strongly associated with MSI. [ABSTRACT FROM AUTHOR]

The article presents reply by the author on comments made by researchers Karl Isaaz and Antoine Gerbay on their article assessing the effect of deferred stent implantation in patients with ST-segment elevation myocardial infarction..