Cardiovascular magnetic resonance-derived intramyocardial hemorrhage after STEMI: Influence on long-term prognosis,adverse left ventricular remodeling and relationship with microvascular obstruction

Background

T2 weighted cardiovascular magnetic resonance (CMR) can detect intramyocardial hemorrhage (IMH) after ST-elevation myocardial infarction (STEMI). The long-term prognostic value of IMH beyond a comprehensive CMR assessment with late enhancement (LE) imaging including microvascular obstruction (MVO) is unclear. The value of CMR-derived IMH for predicting major adverse cardiac events (MACE) and adverse cardiac remodeling after STEMI and its relationship with MVO was analyzed.

Methods

CMR including LE and T2 sequences was performed in 304 patients 1 week after STEMI. Adverse remodeling was defined as dilated left ventricular end-systolic volume indexes (dLVESV) at 6 months CMR.

Results

During a median follow-up of 140 weeks, 47 MACE (10 cardiac deaths, 16 myocardial infarctions, 21 heart failure episodes) occurred. Predictors of MACE were ejection fraction (HR .95 95% CI [.93–.97], p = .001, per %) and IMH (HR 1.17 95% CI [1.03–1.33], p = .01, per segment). The extent of MVO and IMH significantly correlated (r = .951, p < .0001). dLVESV was present in 40% of patients. CMR predictors of dLVESV were: LVESV (OR 1.11 95% CI [1.07–1.15], p < .0001, per ml/m²), infarct size (OR 1.05 95% CI [1.01–1.09], p = .02, per %) and IMH (OR 1.54 95% CI [1.15–2.07], p = .004, per segment). Addition of T2 information did not improve the LE and cine CMR-model for predicting MACE (.744 95% CI [.659–.829] vs. .734 95% CI [.650–.818], p = .6) or dLVESV (.914 95% CI [.875–.952] vs. .913 95% CI [.875–.952], p = .9).

Conclusions

IMH after STEMI predicts MACE and adverse remodeling. Nevertheless, with a strong interrelation with MVO, the addition of T2 imaging does not improve the predictive value of LE-CMR.     

Comprehensive Prognosis Assessment by CMR Imaging After ST-Segment Elevation Myocardial Infarction

Background

Although the prognostic value of findings from cardiac magnetic resonance (CMR) imaging has been established in single-center center studies in patients with ST-segment elevation myocardial infarction (STEMI), a large multicenter investigation to evaluate the prognostic significance of myocardial damage and reperfusion injury is lacking.

Objectives

The aim of this study was to assess the prognostic impact of CMR in an adequately powered multicenter study and to evaluate the most potent CMR predictor of hard clinical events in a STEMI population treated by primary percutaneous coronary intervention (PCI).

Methods

We enrolled 738 STEMI patients in this CMR study at 8 centers. The patients were reperfused by primary PCI <12 h after symptom onset. Central core laboratory–masked analyses for quantified left ventricular (LV) function, infarct size (IS), microvascular obstruction (MO), and myocardial salvage were performed. The primary clinical endpoint of the study was the occurrence of major adverse cardiac events.

Results

Patients with cardiovascular events had significantly larger infarcts (p < 0.001), less myocardial salvage (p = 0.01), a larger extent of MO (p = 0.009), and more pronounced LV dysfunction (p < 0.001). In a multivariate model that included clinical and other established prognostic parameters, MO remained the only significant predictor in addition to the TIMI (Thrombolysis In Myocardial Infarction) risk score. IS and MO provided an incremental prognostic value above clinical risk assessment and LV ejection fraction (c-index increase from 0.761 to 0.801; p = 0.036).

Conclusions

In a large, multicenter STEMI population reperfused by primary PCI, CMR markers of myocardial damage (IS and especially MO) provide independent and incremental prognostic information in addition to clinical risk scores and LV ejection fraction. (Abciximab i.v. Versus i.c. in ST-elevation Myocardial Infarction [AIDA STEMI]; NCT00712101).     

Coronary Microvascular Dysfunction Assessed by Pressure Wire and CMR After STEMI Predicts Long-Term Outcomes

ObjectivesThis study sought to evaluate the long-term prognostic implications of coronary microvascular dysfunction (CMD) when assessed with both cardiovascular magnetic resonance (CMR) and index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).BackgroundPost-ischemic CMD can be assessed using the pressure-wire based IMR and/or by the presence of microvascular obstruction (MVO) on CMR.MethodsA total of 198 patients with STEMI underwent IMR and MVO assessment. Patients were classified as follows: Group 1, no significant CMD (low IMR [≤40 U] and no MVO); Group 2, CMD with either high IMR (>40 U) or MVO; Group 3, CMD with both IMR >40 U and MVO. The primary endpoint was the composite of all-cause mortality, diagnosis of new heart failure, cardiac arrest, sustained ventricular tachycardia/fibrillation, and cardioverter defibrillator implantation.ResultsCMD with both high IMR and MVO was present in 23.7% of the cases (Group 3) and CMD with either high IMR or MVO was observed in 40.9% of cases (Group 2). At a median follow-up of 40.1 months, the primary endpoint occurred in 34 (17%) cases. At 1 year of follow-up, Group 3 (hazard ratio [HR]: 12.6; 95% confidence interval [CI]: 1.6 to 100.6; p = 0.017) but not Group 2 (HR: 7.2; 95% CI: 0.9 to 57.9; p = 0.062) had worse clinical outcomes compared with those with no significant CMD in Group 1. However, in the long-term, patients in Group 2 (HR: 4.2; 95% CI: 1.4 to 12.5; p = 0.009) and those in Group 3 (HR: 5.2; 95% CI: 1.7 to 16.2; p = 0.004) showed similar adverse outcomes, mainly driven by the occurrence of heart failure.ConclusionsPost-ischemic CMD predicts a more than 4-fold increase in long-term risk of adverse outcomes, mainly driven by the occurrence of heart failure. Defining CMD by either invasive IMR >40 U or by CMR-assessed MVO showed similar risk of adverse outcomes.     

Fractional Flow Reserve or Coronary Flow Reserve for the Assessment of Myocardial Perfusion

Purpose of Review

Accumulating evidence exists for the value of coronary physiology for clinical decision-making in ischemic heart disease (IHD). The most frequently used pressure-derived index to assess stenosis severity, the fractional flow reserve (FFR), has long been considered the gold standard for this purpose, despite the fact that the FFR assesses solely epicardial stenosis severity and aims to estimate coronary flow impairment in the coronary circulation. The coronary flow reserve (CFR) directly assesses coronary blood flow in the coronary circulation, including both the epicardial coronary artery and the coronary microvasculature, but is nowadays less established than FFR. It is now recognized that both tools may provide insight into the pathophysiological substrate of ischemic heart disease, and that particularly combined FFR and CFR measurements provide a comprehensive insight into the multilevel involvement of IHD. This review discusses the diagnostic and prognostic characteristics, as well as future implications of combined assessment of FFR and CFR pressure and flow measurements as parameters for inducible ischemia.

Recent Findings

FFR and CFR disagree in up to 40% of all cases, giving rise to fundamental questions regarding the role of FFR in contemporary ischemic heart disease management, and implying a renewed approach in clinical management of these patients using combined coronary pressure and flow measurement to allow appropriate identification of patients at risk for cardiovascular events.

Summary

This review emphasizes the value of comprehensive coronary physiology measurements in assessing the pathophysiological substrate of IHD, and the importance of acknowledging the broad spectrum of epicardial and microcirculatory involvement in IHD. Increasing interest and large clinical trials are expected to further strengthen the potential of advanced coronary physiology in interventional cardiology, consequently inducing reconsideration of current clinical guidelines.

     

Fractional Flow Reserve and Instantaneous Wave-Free Ratio for Nonculprit Stenosis in Patients With Acute Myocardial Infarction

Objectives

The aim of this study was to compare the changes of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) with severity of epicardial coronary stenosis between nonculprit vessel of acute myocardial infarction (AMI) and stable ischemic heart disease (SIHD).

Association of aortic stiffness with biomarkers of myocardial wall stress after myocardial infarction

Background

Aortic pulse wave velocity (PWV) was linked to LV-geometry and -function in patients with kidney disease and non-ischemic cardiomyopathy. The role of aortic compliance after acute STEMI is so far unknown. In the present study, we prospectively investigated the relationship of increased aortic stiffness with biomarkers of myocardial wall stress 4 months after STEMI.

Methods

48 STEMI patients who were reperfused by primary coronary angioplasty underwent cardiovascular magnetic resonance (CMR) at baseline and at 4-month follow-up. The CMR protocol comprised cine-CMR as well as gadolinium contrast-enhanced CMR. Aortic PWV was determined by velocity-encoded, phase-contrast CMR. Blood samples were routinely drawn at baseline and follow-up to determine N-terminal pro-B-type natriuretic peptide (NT-proBNP). In a subgroup of patients, mid-regional pro-adrenomedullin (MR-proADM) and mid-regional pro-A-type natriuretic peptide (MR-proANP) levels were determined.

Results

Patients with a PWV above median (> 7.0 m/s) had significantly higher NT-proBNP, MR-proADM and MR-proANP concentrations at 4-month follow-up than patients with a PWV below median (all p < 0.02). PWV showed moderate to good correlation with NT-proBNP, MR-proAMD and MR-proANP levels 4 months after STEMI (all p < 0.05). Multivariate analysis revealed PWV, beside myocardial infarct size, as an independent predictor of 4-month NT-proBNP levels after correction for age, creatinine and LV ejection fraction (model r: 0.781, p < 0.001).

Conclusion

Aortic stiffness is directly associated with biomarkers of myocardial wall stress 4 months after reperfused STEMI, suggesting a role for aortic stiffness in chronic LV-remodelling.     

Effect of ischemic postconditioning on microvascular obstruction in reperfused myocardial infarction. Results of a randomized study in patients and of an experimental model in swine

Background

Ischemic postconditioning (PCON) appears as a potentially beneficial tool in ST-segment elevation myocardial infarction (STEMI). We evaluated the effect of PCON on microvascular obstruction (MVO) in STEMI patients and in an experimental swine model.

Methods

A prospective randomized study in patients and an experimental study in swine were carried out in two university hospitals in Spain. 101 consecutive STEMI patients were randomized to undergo primary angioplasty followed by PCON or primary angioplasty alone (non-PCON). Using late gadolinium enhancement cardiovascular magnetic resonance, infarct size and MVO were quantified (% of left ventricular mass). In swine, using an angioplasty balloon-induced anterior STEMI model, MVO was defined as the % of area at risk without thioflavin-S staining.

Results

In patients, PCON (n = 49) in comparison with non-PCON (n = 52) did not significantly reduce MVO (0 [0–1.02]% vs. 0 [0–2.1]% p = 0.2) or IS (18 ± 13% vs. 21 ± 14%, p = 0.2). MVO (> 1 segment in the 17-segment model) occurred in 12/49 (25%) PCON and in 18/52 (35%) non-PCON patients, p = 0.3. No significant differences were observed between PCON and non-PCON patients in left ventricular volumes, ejection fraction or the extent of hemorrhage. In the swine model, MVO occurred in 4/6 (67%) PCON and in 4/6 (67%) non-PCON pigs, p = 0.9. The extent of MVO (10 ± 7% vs. 10 ± 8%, p = 0.9) and infarct size (23 ± 14% vs. 24 ± 10%, p = 0.8) was not reduced in PCON compared with non-PCON pigs.

Conclusions

Ischemic postconditioning does not significantly reduce microvascular obstruction in ST-segment elevation myocardial infarction.Clinical Trial Registrationhttp://www.clinicaltrials.gov. Unique identifier: NCT01898546.     

Cardiac Outcomes Through Digital Evaluation (CODE) STEMI project: prehospital digitally-assisted reperfusion strategies

Background

Guidelines for reperfusion in ST-elevation myocardial infarction (STEMI) were recently adopted by the Canadian Cardiovascular Society. We have developed a blended model of prehospital thrombolytic (PHL) therapy or primary percutaneous coronary intervention (PPCI) activation, in order to achieve guideline times.

Methods

In our urban centre of 658,700 people, emergency medical services (EMS) were trained to perform and screen electrocardiograms (ECGs) for suspected STEMI. Suspected ECGs were transmitted to a physician's hand-held device. If the physician confirmed the diagnosis they coordinated initiation of either PHL or PPCI. In cases where physicians found the prehospital ECG negative for STEMI (PHENST), patients were transported to the closest emergency room.

Results

From July 21, 2008 to July 21, 2010, the Cardiac Outcomes Through Digital Evaluation (CODE) STEMI project received 380 transmitted calls. There were 226 confirmed STEMI by the on-call physician, 158 (70%) received PPCI, 48 (21%) received PHL, and 20 (9%) had angiography but no revascularization. The PPCI, median time from first medical contact to reperfusion was 76 minutes (interquartile range [IQR], 64-93). For PHL, median time from first medical contact to needle was 32 minutes (IQR, 29-39). The overall mortality rate for the STEMI patients was 8% (PHL = 4 [8.3%], PPCI = 8 [5%], medical therapy = 7 [35%]). There were 154 PHENST patients, 44% later diagnosed with acute coronary syndrome. The mortality rate for PHENST was 14%.

Conclusions

Through a model of EMS prehospital ECG interpretation, digital transmission, direct communication with a physician, and rapid coordinated service, we demonstrate that benchmark reperfusion times in STEMI can be achieved.     

The Index of Microcirculatory Resistance Postpercutaneous Coronary Intervention Predicts Left Ventricular Recovery in Patients With Thrombolyzed ST‐Segment Elevation Myocardial Infarction

Background

The index of microcirculatory resistance (IMR), an invasive measure of microvascular function, has been shown to correlate with clinical outcomes in patients with ST‐segment elevation myocardial infarction (STEMI). The aim of this study is to evaluate the predictive value of IMR on left ventricular recovery in patients undergoing a pharmacoinvasive strategy for STEMI.

Methods

The index of microcirculatory resistance was assessed following percutaneous coronary intervention (PCI) in 31 patients with STEMI who were initially managed with thrombolysis. Other markers of microvascular function such as coronary flow reserve (CFR), TIMI flow grade, corrected TIMI frame count (cTFC), and ST‐segment resolution were also recorded. All indices were evaluated against measures of left ventricular function and recovery 3 months postindex event.

Results

The IMR correlated with left ventricular function, as assessed by wall motion score and ejection fraction at 3‐month follow‐up (r = 0.652, P = 0.005; r = ?0.452, P = 0.011, respectively). The traditional methods of assessing microvascular function, such as CFR, TIMI flow grade, cTFC, and ST‐segment resolution did not correlate with wall motion score and ejection fraction at 3 months. Post‐PCI IMR was significantly lower in those patients with left ventricular recovery at 3 months (18 U vs 39 U, P < 0.001). The optimal cut‐off value for post‐PCI IMR and left ventricular recovery was 32 U. In patients in whom the IMR was greater than 32 U, the percent change in ejection fraction was significantly lower than in those patients in whom the IMR was less than 32 U (2 ± 11 vs 12 ± 8, P = 0.012).

Conclusions

In patients presenting with STEMI initially managed with thrombolysis and subsequently undergoing PCI, IMR correlates with measures of left ventricular function and has the potential to predict left ventricular recovery at 3 months. (J Interven Cardiol 2016;29:146–154)

     

Distal protection device aggravated microvascular obstruction evaluated by cardiac MR after primary percutaneous intervention for ST-elevation myocardial infarction

Background

Protection of distal embolization by balloon occlusion and thrombus aspiration has not improved microvascular circulation nor decreased myocardial injury during primary percutaneous intervention (PCI) for ST-elevation myocardial infarction (STEMI) in randomized trials. In a prospective randomized trial, we investigated the mechanism of the poor effect of distal protection and thrombus aspiration (DP–TA) in 126 patients with STEMI.

Methods

Patients with first-diagnosed STEMI were randomly assigned to DP–TA pretreatment or conventional PCI (c-PCI). Primary endpoint was reduced left ventricular end-diastolic volume (LVEDV) measured by MRI at post-PCI and 6 months after PCI. Secondary end points were infarct ratio (infarct size to entire LV size) by delayed enhancement (DE), area at risk (AAR) ratio (AAR to entire LV size) by T2 high signal, microvascular occlusion index (MVO) ratio (MVO to entire LV size) by DE, and myocardial salvage index (MSI: (AAR − infarct size) ∗ 100 / AAR) using cardiac magnetic resonance imaging (MRI) within 3 days after PCI.

Results

Baseline characteristics of the patients including cardiovascular risk factors and lesion characteristics were similar between the two groups. DT–PA failed to improve LV remodeling at 6 months (LVEDV 140 ± 39 vs 133 ± 37 in c-PCI group, p = 0.418). Infarct ratio, AAR ratio and MSI were not statistically different between DP–TA group and c-PCI group. However, MVO ratio was significantly larger in DP–TA group than in c-PCI group (2.4 ± 2.7 vs 1.1 ± 1.9, p = 0.045).

Conclusion

DP–TA was potentially hazardous in primary PCI for STEMI by increasing MVO. DP–TA should not be used in STEMI.     

Prognostic value of neutrophil/lymphocyte ratio in patients with ST-elevated myocardial infarction undergoing primary coronary intervention: A prospective,multicenter study

Objective

The pre-procedural neutrophil to lymphocyte ratio (N/L) is associated with adverse outcomes among patients with coronary artery disease but its prognostic value in ST-segment elevation myocardial infarction (STEMI) has not been fully investigated. This study evaluated the relations between pre-procedural N/L ratio and the in-hospital and long-term outcomes in STEMI patients undergoing primary percutaneous coronary intervention (PCI).

Methods

A total of 682 STEMI patients presented within the first 6 h of symptom onset were enrolled and stratified according to tertiles of N/L ratio based on the blood samples obtained in the emergency room upon admission.

Results

The mean follow-up period was 43.3 months (1–131 months). In-hospital in-stent thrombosis, non-fatal myocardial infarction, and cardiovascular mortality increased as the N/L tertile ratio increased (p < 0.001, p < 0.001, p = 0.003, respectively). Long-term in-stent thrombosis, non-fatal myocardial infarction and cardiovascular mortality also increased as the N/L ratio increased (p < 0.001, p < 0.001, p = 0.002, respectively). On multivariate analysis, N/L ratio remained an independent predictor for both in-hospital (OR 1.189, 95% CI 1.000–1.339; p < 0.001) and long-term major (OR 1.228, 95% CI 1.136–1.328; p < 0.001) adverse cardiac events.

Conclusion

The N/L ratio was an independent predictor of both in-hospital and long-term adverse outcomes among STEMI patients undergoing primary PCI. Our findings suggest that this inexpensive, universally available hematological marker may be incorporated into the current established risk assessment model for STEMI.     

Grade 3 ischemia on the admission electrocardiogram is associated with severe microvascular injury on cardiac magnetic resonance imaging after ST elevation myocardial infarction

Background

Grade 3 ischemia during ST elevation myocardial infarction (STEMI) is defined as ST elevation with distortion of the terminal portion of the QRS on electrocardiogram (ECG). The aim of this study was to evaluate the effect of ischemic grade on cardiac magnetic resonance (CMR) imaging infarct characteristics such as infarct size, microvascular obstruction (MVO), intramyocardial hemorrhage (IMH), and myocardial salvage.

Methods

Patients with STEMI treated with primary percutaneous coronary intervention had a 12-lead ECG on presentation for analysis of ischemic grade. Gadolinium-enhanced CMR imaging was performed within 7 days to assess infarct size, MVO, IMH, and myocardial salvage.

Results

Of the 37 patients enrolled in the study, grade 3 ischemia was present in 32%. Those with grade 3 ischemia had higher peak troponin I levels (P = .013), more MVO (P < .001), more IMH (P < .001), larger infarct size (P = .025), and less myocardial salvage (P = .012). Regression analysis found that grade 3 ischemia, infarct size, and peak troponin I level were significantly associated with MVO and IMH.

Conclusion

Grade 3 ischemia on the admission ECG during STEMI is closely associated with the development of severe microvascular damage on CMR imaging.     

Long-Term Incremental Prognostic Value of Cardiovascular Magnetic Resonance After ST-Segment Elevation Myocardial Infarction: A Study of the Collaborative Registry on CMR in STEMI

Objectives

This study sought to investigate whether early post-infarction cardiac magnetic resonance (CMR) parameters provide additional long-term prognostic value beyond traditional outcome predictors in ST-segment elevation myocardial infarction (STEMI) patients.

Angiographic assessment of myocardial perfusion in Tako-Tsubo syndrome

Objectives

To angiographically assess myocardial perfusion in patients with Tako-Tsubo syndrome (TTS) in comparison with control individuals and patients with ST-elevation myocardial infarction (STEMI).

Background

Coronary microvascular dysfunction has been proposed as the pathophysiological mechanism underlying TTS.

Methods

We retrospectively selected consecutive TTS patients showing typical left ventricular (LV) apical dysfunction admitted to our Department in the period 2007–2011 (n = 25). We also enrolled an age and gender-matched control group showing normal coronary arteries (CTR, n = 25), patients with STEMI undergoing primary percutaneous intervention with myocardial reperfusion (SR, n = 25) or microvascular obstruction (SMVO, n = 25). TIMI flow, TIMI frame count (TFC) and both qualitative and quantitative myocardial blush grade in LV apex were assessed. Specifically, myocardial perfusion was quantitatively evaluated using ‘Quantitative Blush Evaluator’ (QuBE), an open source software previously validated in the setting of STEMI.

Results

In TTS, TIMI flow on the LAD was significantly lower and TFC significantly higher compared to CTR and SR (p = 0.008 for both), while it did not significantly differ compared to SMVO (p = 0.06). In TTS, MBG was significantly lower than that in CTR and SR (p = 0.001 for both), while it was significantly higher than that in SMVO (p < 0.001). In TTS, QuBE score was significantly lower than that in CTR and SR (p = 0.001 for both) and higher than in SMVO (p = 0.02).

Conclusions

Our data indicate that myocardial perfusion assessed during angiography is more impaired in patients with TTS than in patients with STEMI exhibiting myocardial reperfusion, while it is less impaired than in patients with STEMI exhibiting MVO.     

Acute effect of primary PCI on diastolic dysfunction recovery in anterior wall STEMI – A non-invasive evaluation by echocardiography

Background

It is well established fact that acute coronary occlusion leads to diastolic dysfunction, followed by systolic dysfunction when myonecrosis occur. It is also proven that primary percutaneous coronary intervention (PPCI) is an excellent therapy for ST elevation myocardial infarction (STEMI) to improve outcomes. However there is a paucity of information on efficacy of PPCI in improving diastolic function. Evaluation of the role of PPCI in improving diastolic dysfunction is required.

Osteoprotegerin in ST-elevation myocardial infarction: Prognostic impact and association with markers of myocardial damage by magnetic resonance imaging

Background/Objectives

For osteoprotegerin (OPG), a cytokine of the tumor necrosis factor superfamily, the prognostic impact in stable coronary artery disease and acute coronary syndromes has been shown recently. In acute ST-elevation myocardial infarction (STEMI) data on the correlation to myocardial damage by cardiac magnetic resonance imaging (CMR) or clinical outcome are lacking.

Methods

We studied 221 consecutive patients with acute STEMI undergoing primary percutaneous coronary intervention (PCI) within 12 h after symptom onset. Serum levels of OPG were determined from samples collected before PCI (OPG0), at 24 (OPG1) and 48 h (OPG2) after reperfusion. CMR studies for assessment of infarct size, reperfusion injury/microvascular obstruction and myocardial salvage were performed within one week after infarction. Long-term clinical follow-up for major adverse cardiovascular events (MACE), defined as death, myocardial infarction, or new onset of congestive heart failure, was performed 18.2 (interquartile range of 9.2–21.2) months after the index event.

Results

OPG levels ≥ 75th percentile were associated with significantly larger infarcts, lower myocardial salvage index and greater extent of microvascular obstruction in CMR as compared to OPG levels < 75th percentile. The MACE rate for patients with OPG levels in the highest quartile was also significantly higher. In a multivariable model adjusted for known risk factors, OPG1 as a continuous variable was independently predictive for MACE.

Conclusion

OPG serum levels collected 24 h after infarction are independent predictors of MACE in acute STEMI patients. High OPG levels are associated with a greater extent of myocardial damage and lower myocardial salvage by CMR.     

A mismatch index based on the difference between measured left ventricular ejection fraction and that estimated by infarct size at three months following reperfused acute myocardial infarction

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.     

Incremental Value of Coronary Microcirculation Resistive Reserve Ratio in Predicting the Extent of Myocardial Infarction in Patients with STEMI. Insights from the Oxford Acute Myocardial Infarction (OxAMI) Study

BackgroundResistive reserve ratio (RRR) is a novel index that expresses the ratio between basal and hyperemic microcirculatory resistance. We sought to compare the performance of RRR, coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in predicting the extent of infarct size (IS) after ST-elevation myocardial infarction.MethodsThermodilution parameters were measured after primary percutaneous coronary intervention (PPCI) in 45 patients. In 30 (67%) cases pre-stenting measurements were also performed to assess the effect of PPCI on myocardial reperfusion, defined by CFR. Cardiovascular magnetic resonance (CMR) was performed at 48-h to assess area-at-risk (AAR), microvascular obstruction (MVO) and IS. CMR was repeated at 6 months in 39/45 patients.ResultsRRR (AUC_RRR = 0.85, CI: 0.71–0.99) performed better compared to CFR (AUC_CFR = 0.67, CI: 0.48–0.86) and IMR (AUC_IMR = 0.70, CI: 0.52–0.88) in predicting IS% at 6-months.Patients with impaired RRR showed larger acute-IS% (27.4 [14.5–42.5] vs 15.4 [8.3–26], p = 0.018), MVO% (3.44 [0–5.97] vs 0 [0–0.89], p = 0.026), AAR% (43 [35–52] vs 34 [25–46], p = 0.03) and 6-months-IS% (22.7 [10.2–35] vs 8.8 [6.9–12.3], p = 0.006), higher rate of adverse remodeling (22.2% vs 0%, p = 0.04) and lower myocardial salvage index (34% [22.8–59.2] vs 53.2% [37.7–71], p = 0.032) compared with other patients.Furthermore, RRR but not IMR or CFR resulted independently associated with 6-months-IS%.CFR (1.48 ± 0.87 vs 1.47 ± 0.61, p = 0.94) did not improve after PPCI in patients with impaired RRR, whereas it improved significantly in other patients (CFR: 1.37 ± 0.43 vs 1.93 ± 0.49, p = 0.018).ConclusionsPatients with post-PPCI impaired RRR were more likely to have suboptimal myocardial reperfusion and larger IS at follow-up. RRR may offer incremental prognostic value compared with other thermodilution-derived indices.     

Diagnosis of Microvascular Angina Using Cardiac Magnetic Resonance

Background

In patients with angina and nonobstructive coronary artery disease (NOCAD), confirming symptoms due to coronary microvascular dysfunction (CMD) remains challenging. Cardiac magnetic resonance (CMR) assesses myocardial perfusion with high spatial resolution and is widely used for diagnosing obstructive coronary artery disease (CAD).

Sex-Related Analysis of Short- and Long-term Clinical Outcomes and Bleeding Among Patients Treated With Primary Percutaneous Coronary Intervention: An Evaluation of the RISK-PCI Data

Background

Unfavourable effect of female sex on short- and long-term clinical outcomes has been demonstrated in unselected ST-elevation acute myocardial infarction (STEMI) patients; the results are conflicting in patients who undergo primary percutaneous coronary intervention (PPCI). The objective of this substudy was to determine whether there are sex-related differences in the 30-day and 1-year clinical outcomes and bleeding after PPCI for STEMI.

Methods

We analyzed 2096 STEMI patients enrolled in the Risk Scoring Model to Predict Net Adverse Cardiovascular Outcomes After Primary Percutaneous Coronary Intervention (RISK-PCI) trial from February 2006 to December 2009. Composite efficacy end point comprised all-cause mortality, nonfatal infarction, and stroke. Safety end point was bleeding classified according to the Thrombolysis in Myocardial Infarction (TIMI) criteria. Net adverse cardiovascular events included composite efficacy end point and total bleeding.

Results

Women in our study were older and presented later than men. After adjustment for potential confounders, there was no difference between sexes with respect to the composite efficacy end point. A higher rate of total bleeding was observed in women (adjusted odds ratio [OR], 1.67; 95% confidence interval [CI], 1.07-2.61 at 30 days, adjusted OR, 1.63; 95% CI, 1.08-2.47 at 1 year) compared with men. Total bleeding was associated with increased mortality at 30 days (OR, 4.87; 95% CI, 2.79-8.47) and at 1 year (OR, 4.43; 95% CI, 2.79-7.02) after PPCI.

Conclusions

We did not find a significant sex-related difference with respect to the composite efficacy end point. Women had a higher rate of total bleeding which was associated with increased short- and long-term mortality. Specific measures aimed at preventing bleeding in women might improve the prognosis of PPCI patients.