Prognostic value of combined magnetic resonance myocardial perfusion imaging and late gadolinium enhancement

Late gadolinium enhancement (LGE) and myocardial perfusion study by cardiac magnetic resonance (CMR) have a diagnostic and prognostic value in patients with suspected coronary artery disease (CAD). The purpose of this study was to determine the prognostic value of combined myocardial perfusion CMR and LGE in patients with known or suspected CAD. We studied patients with known or suspected CAD. All patients underwent CMR for functional study, myocardial perfusion and LGE. Myocardial ischemia by CMR was defined as a perfusion defect in patients without LGE or a perfusion defect beyond the LGE area. Patients were followed up for cardiovascular outcomes including hard cardiac events (cardiac death or non-fatal myocardial infarction) and major adverse cardiac events (MACE) which included cardiac death, non-fatal myocardial infarction, hospitalization for unstable angina, and heart failure. There were a total of 587 men and 645 women. Average age was 64.6 ± 11.1 years. LGE was detected in 326 patients (26.5%). Myocardial ischemia by CMR was detected in 423 patients (34.3%). Average follow-up duration was 34.9 ± 15.6 months. Univariate analysis showed that age, diabetes, use of beta blocker, left ventricular ejection fraction, left ventricular mass, wall motion abnormality, LGE, and myocardial ischemia are predictors for hard cardiac events and MACE. Multivariable analysis revealed that myocardial ischemia was the strongest predictor for hard cardiac events and MACE. Other independent predictors were age, use of beta blocker, and left ventricular mass. Myocardial ischemia by CMR has an incremental prognostic value for cardiac events in patients with known or suspected CAD.     

Appearance of microvascular obstruction on high resolution first-pass perfusion,early and late gadolinium enhancement CMR in patients with acute myocardial infarction

Background

The presence and extent of microvascular obstruction (MO) after acute myocardial infarction can be measured by first-pass gadolinium-enhanced perfusion cardiovascular magnetic resonance (CMR) or after gadolinium injection with early or late enhancement (EGE/LGE) imaging. The volume of MO measured by these three methods may differ because contrast agent diffusion into the MO reduces its apparent extent over time. Theoretically, first-pass perfusion CMR should be the most accurate method to measure MO, but this technique has been limited by lower spatial resolution than EGE and LGE as well as incomplete cardiac coverage. These limitations of perfusion CMR can be overcome using spatio-temporal undersampling methods. The purpose of this study was to compare the extent of MO by high resolution first-pass k-t SENSE accelerated perfusion, EGE and LGE.

Methods

34 patients with acute ST elevation myocardial infarction, treated successfully with primary percutaneous coronary intervention (PPCI), underwent CMR within 72 hours of admission. k-t SENSE accelerated first-pass perfusion MR (7 fold acceleration, spatial resolution 1.5 mm × 1.5 mm × 10 mm, 8 slices acquired over 2 RR intervals, 0.1 mmol/kg Gd-DTPA), EGE (1-4 minutes after injection with a fixed TI of 440 ms) and LGE images (10-12 minutes after injection, TI determined by a Look-Locker scout) were acquired. MO volume was determined for each technique by manual planimetry and summation of discs methodology.

Results

k-t SENSE first-pass perfusion detected more cases of MO than EGE and LGE (22 vs. 20 vs. 14, respectively). The extent of MO imaged by first-pass perfusion (median mass 4.7 g, IQR 6.7) was greater than by EGE (median mass 2.3 g, IQR 7.1, p = 0.002) and LGE (median mass 0.2 g, IQR 2.4, p = 0.0003). The correlation coefficient between MO mass measured by first-pass perfusion and EGE was 0.91 (p < 0.001).

Conclusion

The extent of MO following acute myocardial infarction appears larger on high-resolution first-pass perfusion CMR than on EGE and LGE. Given the inevitable time delay between gadolinium administration and acquisition of either EGE or LGE images, high resolution first-pass perfusion imaging may be the most accurate method to quantify MO.     

Dressler's syndrome demonstrated by late gadolinium enhancement cardiovascular magnetic resonance

A 49-year old patient presented late with an anterolateral ST-elevation myocardial infarction and was treated with rescue angioplasty to an occluded left anterior descending artery. Her recovery was complicated by low-grade pyrexia and raised inflammatory markers. Cardiovascular magnetic resonance 5 weeks after the acute presentation showed transmural infarction and global late gadolinium enhancement of the pericardium in keeping with Dressler''s syndrome.     

Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance

Background

Early and late microvascular obstruction (MVO) assessed by cardiovascular magnetic resonance (CMR) are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI). However, there is a lack of studies with long-term follow-up periods (>24 months).

Methods

STEMI patients reperfused by primary angioplasty (n = 129) underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %), left ventricular myocardial mass (LVMM) and total infarct size (% of LVMM) were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization.

Results

Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002) and a lower EF (mean: 39% vs. 46%, p = 0.006). The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p < 0.05). The presence of early MVO was associated with a reduced event-free survival (log-rank p < 0.05). Early MVO was identified as the strongest independent predictor for the occurrence of the primary endpoint in the multivariable Cox regression analysis adjusting for age, ejection fraction and infarct size (hazard ratio: 2.79, 95%-CI 1.25-6.25, p = 0.012).

Conclusion

Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.     

Combined magnetic resonance coronary artery imaging,myocardial perfusion and late gadolinium enhancement in patients with suspected coronary artery disease

Background

Cardiovascular Magnetic Resonance (CMR) imaging offers methods for the detection of ischemia and myocardial infarction as well as visualization of the coronary arteries (MRCA). However, a direct comparison of adenosine perfusion (PERF), late gadolinium enhancement (LGE) and MRCA or the results of their combination has not been performed. Aim of the study was to evaluate the feasibility/diagnostic performance of rest/stress perfusion, late gadolinium enhancement and MRCA and their combination in patients with suspected coronary artery disease (CAD) in comparison to invasive angiography.

Methods

Fifty-four patients (60 ± 10 years, 35 men, CAD 48%) underwent CMR including MRCA (steady state free precession, navigator whole heart approach, spatial resolution 0.7 × 0.7 × .0.9 mm, trigger delay and temporal resolution adjusted individually), stress PERF (adenosine 140 μg/min/kg), rest PERF (SSFP, 3 short axis, 1 saturation prepulse per slice) and LGE (3D inversion recovery technique) using Gd-BOPTA. Images were analyzed visually. Stenosis >50% in invasive angiography was considered significant.

Results

Mean study time was 68 ± 11 minutes. Sensitivity for PERF, LGE, MRCA and the combination of PERF/LGE and PERF/LGE/MRCA was 87%, 50%, 91%, 88% and 92%, respectively and specificity 88%, 96%, 46%, 88% and 56%, respectively. If image quality of MRCA was excellent (n = 18) the combination of MRCA/PERF/LGE yield a sensitivity of 86% and specificity of 91%. However, no test or combination improved diagnostic performance significantly compared to PERF alone.

Conclusion

In patients with CAD, the combination of stress PERF, LGE and MRCA is feasible. When compared to invasive angiography, adenosine stress perfusion outperforms CMR coronary angiography in direct comparison and yields the best results with non-significant improvement in combination with LGE and significant deterioration in combination with MRCA. MRCA may be of additional value only in a minority of patients with excellent image quality.     

Mechanism of late gadolinium enhancement in patients with acute myocardial infarction.

PURPOSE: To investigate the mechanism of late gadolinium enhancement in irreversibly damaged myocardium in patients with acute myocardial infarct by determining kinetics of Gd-DTPA over time. METHODS: Twenty-nine patients (24 men; 64 +/- 9 years) with acute myocardial infarction were imaged with functional and gadolinium enhanced cardiovascular magnetic resonance (CMR) 18 minutes post 0.2 mmol/kg Gd-DTPA. T1 of blood, remote and enhanced myocardium, as well as microvascular obstruction (MVO) was determined before and 5-40 minutes post contrast injection (Look-Locker), and the partition coefficient (lambda) was calculated. RESULTS: T1 and lambda were significantly different from 5-40 minutes post contrast in enhanced (lambda = 0.90 +/- 0.09, p < 0.001) compared to remote myocardium (lambda = 0.40 +/- 0.07). lambda achieved a steady state in remote but increased continuously in infarcted myocardium and to an even greater extent in MVO. T1 of enhanced myocardium was higher from 5-15 minutes, equal at 20 minutes and lower 25-40 minutes post contrast compared to blood, indicating a changing contrast between blood and late gadolinium enhancement over time. CONCLUSION: Enhancement in patients with acute infarction is mainly due to an increased lambda, although reduced wash-in-wash-out adds to the effect. Differentiation between blood and enhanced myocardium may be difficult to achieve, if only little differences of T1 are available. Imaging at a later point will restore the contrast.     

Myocardial late gadolinium enhancement cardiovascular magnetic resonance in patients with cirrhosis

Background

Portal hypertension and cardiac alterations previously described as "cirrhotic cardiomyopathy" are known complications of end stage liver disease (ELD). Cardiac failure contributes to morbidity and mortality, particularly after liver transplantation and transjugular intrahepatic portosystemic shunt (TIPS). We sought to identify myocardial tissue characterization and evaluate cardiovascular magnetic resonance (CMR) for diagnosis of cardiac impairment.

Results

Twenty ELD patients underwent CMR for morphological, functional and tissue characterization by late gadolinium enhancement (LGE). Based on extent of LGE, patients were dichotomized into high and low LGE groups and analyzed regarding liver, cardiocirculatory and renal functions. CMR demonstrated hyperdynamic left ventricular function and a patchy pattern of LGE of the myocardium to a variable extent (range 2-62%) in all patients. There were no significant differences in Model for End-Stage Liver Disease (MELD), Child-Pugh score or the left ventricular ejection fraction between high and low LGE groups. QTc-interval was prolonged in 25% of the patients. E/A ratio was at the upper limit of norm; no difference between groups. Patients showing high LGE had a higher CI (p < 0.05). Biomarkers of myocardial stress were elevated. While NT-proBNP and c-Troponin-T showed no differences, PLGF and sFLT1 were lower in the high LGE group.

Conclusion

CMR shows myocardial involvement in patients with ELD resembling appearance of myocarditis. The hyperdynamic circulation in portal hypertension may be an important factor. Larger prospective trials are warranted to confirm the association with severity and outcome of liver disease and to test the predictive power of CMR for patients listed for liver transplantation.     

Focal myocardial fibrosis assessed by late gadolinium enhancement cardiovascular magnetic resonance in children and adolescents with dilated cardiomyopathy

Background

Different patterns of late gadolinium enhancement (LGE) including mid-wall fibrosis using cardiovascular magnetic resonance (CMR) have been reported in adult patients presenting with non-ischemic dilated cardiomyopathy (DCM). In these studies, LGE was associated with pronounced LV remodelling and predicted adverse cardiac outcomes. Accordingly, the purpose of our study was to determine the presence and patterns of LGE in children and adolescents with DCM.

Methods

Patients <18 years of age presenting with severe congestive heart failure who were admitted for evaluation of heart transplantation at our centre underwent CMR examination which consisted of ventricular functional analysis and assessment of LGE for detection of myocardial fibrosis. Ischemic DCM was excluded by coronary angiography, and right ventricular endomyocardial biopsies ruled out acute myocarditis.

Results

Thirty-one patients (mean age 2.1 ± 4.2 years) with severe LV dilatation (mean indexed LVEDV 136 ± 48 ml/m²) and LV dysfunction (mean LV-EF 23 ± 8%) were examined. LGE was detected in 5 of the 31 patients (16%) appearing in various patterns characterized as mid-wall (n = 1), focal patchy (n = 1), RV insertion site (n = 1) and transmural (n = 2). Based on histopathological analysis, 4 of the 5 LGE positive patients had lymphocytic myocarditis, whereas one patient was diagnosed with idiopathic DCM.

Conclusions

In children and adolescents with DCM, focal histologically proven myocardial fibrosis is rarely detected by LGE CMR despite marked LV dilatation and severely depressed LV function. LGE occurred in various patterns and mostly in patients with inflammatory cardiomyopathy. It remains unclear whether myocardial fibrosis in childhood DCM reflects different endogenous repair mechanisms that enable favourable reverse remodelling. Larger trials are needed to assess the prognostic implications of LGE in childhood DCM.     

Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method. There was a moderate correlation between the two methods (r = 0.86; P < 0.001). The AAR was significantly higher measured with T2-weighted imaging than with the ESA methods (32 ± 11% of left ventricle (LV) vs. 26 ± 10%LV; P < 0.001). The mean difference was 6 ± 6%LV. Furthermore, the mean difference between the two methods was statistical higher in the patients with myocardial salvage index ≥0.90 than in the remaining patients (9 ± 8%LV vs. 6 ± 5%LV; P = 0.02). The ESA method performed after scar remodeling (3 months following STEMI) yields significantly lower AAR′s and myocardial salvage indices compared to the T2-weighted method. Therefore, T2-weighted CMR plus LGE is the method of choice to assess AAR and myocardial salvage index using CMR. However, the ESA method is an easy and valid method for determining AAR, which can be used in settings where T2-weighted imaging has not been obtained in the acute phase.     

磁共振心肌首过灌注成像评价肥厚型心肌病微循环功能障碍

目的 应用MR心肌首过灌注成像评价肥厚型心肌病患者局部心肌微循环障碍.方法 选取22例肥厚型心肌病患者(HCM组)和13名健康志愿者(对照组)行心脏MR (CMR)检查(包括左心室短轴电影、心肌首过灌注和延迟增强序列),测量左心室舒张末期各心肌节段心肌壁厚度、心肌信号强度最大上升斜率(Slopemax)和心肌延迟强化(DE).采用单因素方差分析比较对照组心肌节段、HCM组非肥厚性心肌节段亚组和肥厚性心肌节段亚组的Slopemaax以及不同肥厚程度心肌节段的SlopemaX,对有DE心肌节段和无DE心肌节段的Slopemax的差异采用独立样本t检验进行分析.结果 HCM组中非肥厚性心肌节段亚组和肥厚性心肌节段亚组Slopemax均明显低于对照组(P均<0.05),其中肥厚性心肌节段亚组的Slopemax较非肥厚性心肌节段亚组降低更为显著(P＜0.05);轻度肥厚心肌节段Sl0pemax高于中度、重度肥厚心肌节段(P均＜0.05),但中度与重度心肌肥厚节段Slopemax的差异无统计学意义(P＞0.05).DE心肌节段Slopemax明显低于无DE心肌节段(P＜0.05).结论 MR心肌首过灌注成像能可靠地检出HCM局部心肌的微血管功能障碍,为临床对HCM患者进行风险分层、制定治疗计划和预后评估提供有价值的信息.     

Prognosis of early pre-discharge and late left ventricular dilatation by cardiac magnetic resonance imaging after acute myocardial infarction

The International Journal of Cardiovascular Imaging - To study the long-term prognosis of early pre-discharge and late left ventricular (LV) dilatation in patients with first ST-elevation...     

Low prevalence of fibrosis in thalassemia major assessed by late gadolinium enhancement cardiovascular magnetic resonance

Background

Heart failure remains a major cause of mortality in thalassaemia major. The possible role of cardiac fibrosis in thalassemia major in the genesis of heart failure is not clear. It is also unclear whether cardiac fibrosis might arise as a result of heart failure.

Methods

We studied 45 patients with thalassaemia major who had a wide range of current cardiac iron loading and included patients with prior and current heart failure. Myocardial iron was measured using T2* cardiovascular magnetic resonance (CMR), and following this, late gadolinium enhancement (LGE) was used to determine the presence of macroscopic myocardial fibrosis.

Results

The median myocardial T2* in all patients was 22.6 ms (range 5.3-58.8 ms). Fibrosis was detected in only one patient, whose myocardial T2* was 20.1 ms and left ventricular ejection fraction 57%. No fibrosis was identified in 5 patients with a history of heart failure with full recovery, in 3 patients with current left ventricular dysfunction undergoing treatment, or in 18 patients with myocardial iron loading with cardiacT2* < 20 ms at the time of scan.

Conclusion

This study shows that macroscopic myocardial fibrosis is uncommon in thalassemia major across a broad spectrum of myocardial iron loading. Importantly, there was no macroscopic fibrosis in patients with current or prior heart failure, or in patients with myocardial iron loading without heart failure. Therefore if myocardial fibrosis indeed contributes to myocardial dysfunction in thalassemia, our data combined with the knowledge that the myocardial dysfunction of iron overload can be reversed, indicates that any such fibrosis would need to be both microscopic and reversible.     

AL cardiac amyloidosis with widespread myocardial infiltration in the absence of hyperenhancement on conventional magnitude late gadolinium enhancement cardiovascular magnetic resonance imaging

The International Journal of Cardiovascular Imaging -     

A review of 3D first-pass,whole-heart,myocardial perfusion cardiovascular magnetic resonance

A comprehensive review is undertaken of the methods available for 3D whole-heart first-pass perfusion (FPP) and their application to date, with particular focus on possible acceleration techniques. Following a summary of the parameters typically desired of 3D FPP methods, the review explains the mechanisms of key acceleration techniques and their potential use in FPP for attaining 3D acquisitions. The mechanisms include rapid sequences, non-Cartesian k-space trajectories, reduced k-space acquisitions, parallel imaging reconstructions and compressed sensing. An attempt is made to explain, rather than simply state, the varying methods with the hope that it will give an appreciation of the different components making up a 3D FPP protocol. Basic estimates demonstrating the required total acceleration factors in typical 3D FPP cases are included, providing context for the extent that each acceleration method can contribute to the required imaging speed, as well as potential limitations in present 3D FPP literature. Although many 3D FPP methods are too early in development for the type of clinical trials required to show any clear benefit over current 2D FPP methods, the review includes the small but growing quantity of clinical research work already using 3D FPP, alongside the more technical work. Broader challenges concerning FPP such as quantitative analysis are not covered, but challenges with particular impact on 3D FPP methods, particularly with regards to motion effects, are discussed along with anticipated future work in the field.     

Regional myocardial perfusion abnormalities: Fractional flow reserve versus cardiac magnetic resonance first-pass perfusion imaging

Identification of the functional severity of intermediate coronary artery lesions is challenging for the interventional cardiologist. Functional severity can be measured invasively using the fractional flow reserve (FFR). However, FFR has the disadvantage of being invasive and associated with radiation exposure. Cardiac MRI (CMR) offers the opportunity to assess myocardial perfusion noninvasively. A semiquantitative index of myocardial perfusion (perfusion reserve index or PRI) can be obtained from the first-pass of a bolus of gadolinium through the myocardium. Studies comparing the invasive FFR to CMR perfusion imaging in patients with coronary artery stenosis of undefined significance have demonstrated that CMR first-pass perfusion imaging may be useful for the assessment of their functional significance. However, in patients with a high prevalence of microvascular dysfunction, the value of this method may be limited because the PRI may be influenced by both the epicardial conductance vessel function as well as microvascular function.     

Myocardial perfusion reserve in cardiovascular magnetic resonance: Correlation to coronary microvascular dysfunction.

The present study examined the association of myocardial perfusion reserve index (MPRI) in cardiovascular magnetic resonance (CMR) with coronary microvascular dysfunction (CMD) and serum levels of markers of inflammation or endothelial activation. Twelve patients with typical angina pectoris without coronary artery disease were enrolled in this study, and CMR perfusion was analyzed using a steady-state-free-precession sequence with 3 short axis slices per heartbeat during first pass of 0.025 mmol Gadolinium-DTPA/kg body weight. The upslope of myocardial signal intensity curves was used to calculate MPRI. CMD was assessed by intracoronary Doppler flow measurement and biplane angiography. Both MPRI and CMD were assessed during endothelium-independent stimulation with intravenous adenosine and during endothelium-dependent stimulation with intracoronary infusion of acetylcholine. Serum values of soluble CD40 ligand (sCD40L), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and C-reactive protein (CRP) were measured. Impaired MPRI correlated significantly with a decrease in coronary blood flow reserve after both endothelium-dependent (p = 0.033) and endothelium-independent (p = 0.022) stimulation. Serum levels above the median of all normal ranged biomarkers sCD40L, TNF-alpha, IL-6, sICAM-1 and CRP were associated with an impaired MPRI for stimulation with adenosine as well as acetylcholine. In multivariable analyses, sCD40L (p < 0.001) and TNF-alpha (p = 0.011) were significantly associated with a decrease in MPRI on adenosine, as were TNF-alpha (p = 0.016) and sICAM-1 (p = 0.022) for a decrease in MPRI on acetylcholine. MPRI on adenosine significantly correlated with MPRI on acetylcholine (p < 0.001). Therefore, the present study demonstrates safety and feasibility of an intracoronary infusion of acetylcholine during CMR perfusion analysis, thus allowing direct assessment of endothelial dependent vasomotor function at the myocardial level by CMR. Furthermore, we show that an impaired myocardial perfusion reserved in CMR is associated with established biomarkers of early atherosclerosis and significantly correlated with CMD. CMR combined with adenosine could be proposed as a non-invasive tool to evaluate CMD.     

Quantification of myocardial perfusion by cardiovascular magnetic resonance

The potential of contrast-enhanced cardiovascular magnetic resonance (CMR) for a quantitative assessment of myocardial perfusion has been explored for more than a decade now, with encouraging results from comparisons with accepted "gold standards", such as microspheres used in the physiology laboratory. This has generated an increasing interest in the requirements and methodological approaches for the non-invasive quantification of myocardial blood flow by CMR. This review provides a synopsis of the current status of the field, and introduces the reader to the technical aspects of perfusion quantification by CMR. The field has reached a stage, where quantification of myocardial perfusion is no longer a claim exclusive to nuclear imaging techniques. CMR may in fact offer important advantages like the absence of ionizing radiation, high spatial resolution, and an unmatched versatility to combine the interrogation of the perfusion status with a comprehensive tissue characterization. Further progress will depend on successful dissemination of the techniques for perfusion quantification among the CMR community.     

Gender differences in contrast-enhanced magnetic resonance imaging after acute myocardial infarction

Besides different risk profiles for cardiovascular events in men and women, several studies reported gender differences in mortality after acute myocardial infarction (AMI). As infarct size has been shown to correlate with mortality, it is widely accepted as surrogate marker for clinical outcome. Currently, cardiovascular imaging studies covering the issue of gender differences are rare. As magnetic resonance scar characterization parameters are emerging as additional prognostic factors after acute myocardial infarction, we sought to evaluate gender differences in CMR infarct characteristics in patients after acute myocardial infarction. We prospectively analyzed patients (n = 448) with AMI and primary angioplasty, who underwent contrast enhanced cardiac magnetic resonance (CMR) imaging on a 1.5 T scanner in median 5 [Galatius-Jensen et al. in BMJ 313(7050):137–140, (1996), Burns et al. in J Am Coll Cardiol 39(1):30–36, (2002)] days after the acute event. CMR scar size was measured 15 min after gadolinium injection. In addition presence and extent of microvascular obstruction (MVO) was assessed. A matched pair analysis was performed in order to exclude confounding by gender related co-morbidities and gender differences in established clinical risk factors. Matching process according to clinical risk defined by GRACE score resulted in 93 mixed gender couples. Women were significantly older than men (64.4 ± 11.9 vs. 60.5 ± 12.3, p = 0.03) and presented with a significantly better ejection fraction before angioplasty (48.9 ± 8.4 vs. 46.2 ± 8.9, p = 0.04). Infarct size did not differ significantly between women and men (13.5 ± 10.7 vs. 15.1 ± 11.8, p = 0.32). Size of MVO was significantly smaller in women than in men (0.48 ± 1.3 vs. 1.2 ± 3.0, p = 0.03). Comparing scar characterization between women and men with similar risk profiles revealed no gender differences in scar size. Size of MVO, however, was significantly smaller in women and might reflect better cardioprotective mechanisms in women. Whether these changes have prognostic implications has to be tested on a larger patient population.