Impact of gender differences on myocardial salvage and post-ischaemic left ventricular remodelling after primary coronary angioplasty: new insights from cardiovascular magnetic resonance

Sex differences in diagnostic modalities of coronary artery disease: Evidence from coronary microcirculation

Although atherosclerosis is usually considered a disease of the large arteries, risk factors for atherosclerosis also trigger structural and functional abnormalities at a microvascular level. In cardiac disease, microvascular dysfunction is especially relevant in women, among whom the manifestation of ischemic disease due to impaired coronary microcirculation is more common than in men. This sex-specific clinical phenotype has important clinical implications and, given the higher pre-test probability of coronary microvascular dysfunction in females, different diagnostic modalities should be used in women compared to men. In this review, we summarize invasive and non-invasive diagnostic modalities to assess coronary microvascular function, ranging from catheter-based evaluation of endothelial function to Doppler echocardiography and positron emission tomography. Moreover, we discuss different clinical settings in which microvascular disease plays an important role, underlining the importance of choosing the right diagnostic modality depending on the sex of the patients.

The optimal definition and prediction nomogram for left ventricular remodelling after acute myocardial infarction

AIMS

Left ventricular (LV) remodelling after acute myocardial infarction (AMI) is associated with heart failure and increased mortality. There was no consensus on the definition of LV remodelling, and the prognostic value of LV remodelling with different definitions has not been compared. We aimed to find the optimal definition and develop a prediction nomogram as well as online calculator that can identify patients at risk of LV remodelling.

METHODS AND RESULTS

This prospective, observational study included 829 AMI patients undergoing percutaneous coronary intervention from January 2015 to January 2020. Echocardiography was performed within the 48 h of admission and at 6 months after infarction to evaluate LV remodelling, defined as a 20% increase in LV end-diastolic volume (LVEDV), a 15% increase in LV end-systolic volume (LVESV), or LV ejection fraction (LVEF) < 50% at 6 months. The impact of LV remodelling on long-term outcomes was analysed. Lasso regression was performed to screen potential predictors, and multivariable logistic regression analysis was conducted to establish the prediction nomogram. The area under the curve, calibration curve and decision curve analyses were used to determine the discrimination, calibration and clinical usefulness of the remodelling nomogram. The incidences of LV remodelling defined by LVEDV, LVESV and LVEF were 24.85% (n = 206), 28.71% (n = 238) and 14.60% (n = 121), respectively. Multivariable Cox regression models demonstrated that different definitions of LV remodelling were independently associated with the composite endpoint. However, only remodelling defined by LVEF was significantly connected with long-term mortality (hazard ratio = 2.78, 95% confidence interval 1.41-5.48, P = 0.003). Seven variables were selected to construct the remodelling nomogram, including diastolic blood pressure, heart rate, AMI type, stent length, N-terminal pro brain natriuretic peptide, troponin I, and glucose. The prediction model had an area under the receiver operating characteristics curve of 0.766. The calibration curve and decision curve analysis indicated consistency and better net benefit in the prediction model.

CONCLUSIONS

LV remodelling defined by LVEDV, LVESV and LVEF were independent predictors for long-term mortality or heart failure hospitalization in AMI patients after percutaneous coronary intervention. However, only remodelling defined by LVEF was suitable for predicting all-cause death. In addition, the nomogram can provide an accurate and effective tool for the prediction of postinfarct remodelling.

Rapamycin treatment unmasks a sex-specific pattern of scar expansion of the infarcted rat heart: The relationship between mTOR and KATP channel

Inhibition of the mammalian target of rapamycin (mTOR) with the macrolide rapamycin or pharmacological suppression of KATP channel opening translated to scar expansion of the myocardial infarcted (MI) adult female rodent heart. The present study tested the hypotheses that rapamycin-mediated scar expansion was sex-specific and that mTOR signaling directly influenced KATP channel subunit expression/activity. Scar size was significantly larger in post-MI male rats as compared to the previous data reported in post-MI female rats. The reported scar expansion of rapamycin-treated post-MI female rats was not observed following the administration of the macrolide to post-MI male rats. Protein levels of the KATP channel subunits Kir6.2 and SUR2A and phosphorylation of the serine2448 residue of mTOR were similar in the normal heart of adult male and female rats. By contrast, greater tuberin inactivation characterized by the increased phosphorylation of the threonine1462 residue and reduced raptor protein levels were identified in the normal heart of adult female rats. Rapamycin pretreatment of phorbol 12,13-dibutyrate (PDBu)-treated neonatal rat ventricular cardiomyocytes (NNVMs) suppressed hypertrophy, inhibited p70S6K phosphorylation, and attenuated SUR2A protein upregulation. In the presence of low ATP levels, KATP channel activity detected in untreated NNVMs was significantly attenuated in PDBu-induced hypertrophied NNVMs via a rapamycin-independent pathway. Thus, rapamycin administration to post-MI rats unmasked a sex-specific pattern of scar expansion and mTOR signaling in PDBu-induced hypertrophied NNVMs significantly increased SUR2A protein levels. However, the biological advantage associated with SUR2A protein upregulation was partially offset by an mTOR-independent pathway that attenuated KATP channel activity in PDBu-induced hypertrophied NNVMs.

Imaging of heart disease in women: review and case presentation

Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. Although major diagnostic and therapeutic advances have significantly improved the prognosis of patients with CVD in the past decades, these advances have less benefited women than age-matched men. Noninvasive cardiac imaging plays a key role in the diagnosis of CVD. Despite shared imaging features and strategies between both sexes, there are critical sex disparities that warrant careful consideration, related to the selection of the most suited imaging techniques, to technical limitations, and to specific diseases that are overrepresented in the female population. Taking these sex disparities into consideration holds promise to improve management and alleviate the burden of CVD in women. In this review, we summarize the specific features of cardiac imaging in four of the most common presentations of CVD in the female population including coronary artery disease, heart failure, pregnancy complications, and heart disease in oncology, thereby highlighting contemporary strengths and limitations. We further propose diagnostic algorithms tailored to women that might help in selecting the most appropriate imaging modality.

No sex-related differences in infarct size, no-reflow and protection by ischaemic preconditioning in Göttingen minipigs

Aims

Female sex has been proposed to be cardioprotective per se. Studies with myocardial ischaemia/reperfusion and infarct size as endpoint have demonstrated cardioprotection in female, castrated male and male pigs. These studies are difficult to compare, given the different pig strains, models, durations of ischaemia and methods of infarct size quantification. The few studies using both female and male pigs reported no differences in infarct size and cardioprotection. We therefore prospectively compared infarct size in Göttingen minipigs undergoing ischaemia/reperfusion (I/R) without and with ischaemic preconditioning (IPC) between female, castrated male and male pigs.

Methods and Results

In a prospective, randomised approach, 28 Göttingen open-chest, anaesthetised minipigs underwent 60 min ischaemia by distal left anterior descending artery (LAD) occlusion and 180 min reperfusion without and with IPC by 3 cycles of 5 min LAD occlusion/10 min reperfusion. Infarct size with I/R was not different between female, castrated male and male pigs (45±8 vs. 45±13 vs. 41±9% area at risk), as was the reduction in infarct size with IPC (25±11 vs. 30±8 vs. 19±10% area at risk). Also, the area of no-reflow was not different between female, castrated male and male pigs with I/R (57±13 vs. 35±7 vs. 47±26% infarct size) or IPC (4±10 vs.12±20 vs. 0±0% infarct size). Phosphorylation of signal transducer and activator of transcription 3 was increased at 10 min reperfusion by IPC but not by I/R to the same extent in female, castrated male and male pigs (198±30 vs. 230±165 vs. 179±107% of baseline).

Conclusion

Our data do not support the notion of sex- or castration-related differences in infarct size, coronary microvascular injury and cardioprotection by ischaemic preconditioning.

Translational perspective

The translation of successful preclinical studies on cardioprotection to the benefit of patients with reperfused myocardial infarction has been difficult. The difficulties have been attributed to confounders such as co-morbidities and co-medications which patients typically have but animals don´t, but also to age and sex. Notably, female sex has been considered as protective per se. We have now, using our established and clinically relevant pig model of reperfused acute myocardial infarction and ischaemic preconditioning as the most robust cardioprotective intervention looked for sex-related differences of infarct size, no-reflow and cardioprotection by ischaemic preconditioning in a prospectively powered approach but found none such difference.

Protective Value of Aspirin Loading Dose on Left Ventricular Remodeling After ST-Elevation Myocardial Infarction

Aims

Left ventricular (LV) remodeling after ST-elevation myocardial infarction (STEMI) is a complex process, defined as changes of LV volumes over time. CMR feature tracking analysis (CMR-FT) offers an accurate quantitative assessment of LV wall deformation and myocardial contractile function. This study aimed to evaluate the role of myocardial strain parameters in predicting LV remodeling and to investigate the effect of Aspirin (ASA) dose before primary coronary angioplasty (pPCI) on myocardial injury and early LV remodeling.

Methods and Results

Seventy-eight patients undergoing CMR, within 9 days from symptom onset and after 6 months, were enrolled in this cohort retrospective study. We divided the study population into three groups based on a revised Bullock's classification and we evaluated the role of baseline CMR features in predicting early LV remodeling. Regarding CMR strain analysis, worse global circumferential and longitudinal strain (GCS and GLS) values were associated with adverse LV remodeling. Patients were also divided based on pre-pPCI ASA dosage. Significant differences were detected in patients receiving ASA 500 mg dose before pPCI, which showed lower infarct size extent and better strain values compared to those treated with ASA 250 mg. The stepwise multivariate logistic regression analysis, adjusted for covariates, indicated that a 500 mg ASA dose remained an inverse independent predictor of early adverse LV remodeling.

Conclusion

GCS and GLS have high specificity to detect early LV adverse remodeling. We first reported a protective effect of ASA loading dose of 500 mg before pPCI on LV myocardial damage and in reducing early LV adverse remodeling.

Development and Validation of a Clinical and Laboratory-Based Nomogram for Predicting Coronary Microvascular Obstruction in NSTEMI Patients After Primary PCI

Objective

Cardiac microvascular obstruction (CMVO) remains a severe complication in non-ST elevation myocardial infarction (NSTEMI) patients with reperfusion therapy. We aimed at developing and validating the nomogram to predict the possibility of CMVO after primary percutaneous coronary intervention (PCI) by integrating clinical and laboratory-based information.

Methods

A total of 325 patients undergoing primary PCI for NSTEMI were recruited and divided into the training cohort (n=226) and the validating cohort (n = 99). The development of the nomogram was based on independent predictors of CMVO, and these variables were selected by multivariable logistic regression analysis.

Results

Independent predictors contained in nomogram were identified by multivariable logistic regression analysis, and these independent predictors included neutrophils (OR 1.166, 95% CI 1.044–1.303, P<0.01), hemoglobin (OR 1.037, 95% CI 1.013–1.062, P<0.01), triglyceride (OR 1.343, 95% CI 1.059; 1.704, P=0.015), Killip grade (OR 2.190, 95% CI 1.065–4.503, P=0.033), high thrombus load (OR 3.146, 95% CI 1.424–6.952, P<0.01), no-reflow (OR 3.142, 95% CI 1.419–6.955, P<0.01) and ischemic postconditioning (OR 0.445, 95% CI 0.209–0.944, P=0.035). The nomogram accurately predicted the presentation of CMVO in both the training set and validating set (AUC, 0.835 and 0.881, respectively). The results predicted by nomogram were confirmed to be highly consistent with the results of DE-CMR, both the training and validating cohorts, by Calibration plot and Hosmer-Lemeshow test. Decision curve analysis (DCA) also suggested that the nomogram was applicable in the clinic.

Conclusion

The nomogram showed good performance in predicting CMVO, and it could help clinicians optimize the clinical treatments to improve the prognosis of NSTEMI patients.

Sex-related differences in ventricular remodeling after myocardial infarction

The epidemiology, clinical features and outcome of myocardial infarction (MI) display significant differences between men and women. Prominent sex differences have also been suggested in left ventricular (LV) remodeling after MI. Ventricular remodeling refers to a deterioration of LV geometry and function often leading to heart failure (HF) development and an increased risk of adverse cardiovascular events. Women have a lower propensity to the acquisition of a spherical geometry and LV dysfunction. These differences can be attributed at least partially to a lower frequency of transmural infarction and smaller areas of microvascular obstruction in women, as well as to a less prominent activation of neuroendocrine systems and apoptotic, inflammatory and profibrotic pathways in women. Estrogens might play a role in this difference, which could partially persist even after the menopause because of a persisting intramyocardial synthesis of estrogens in women. Conversely, androgens may exert a detrimental influence. Future studies should better clarify sex differences in the predictors, clinical correlates, prognostic impact and disease mechanisms of remodeling, as well as the existence of sex-specific therapeutic targets. This research effort should hopefully allow to optimize the treatment of MI during the acute and post-acute phase, possibly through different therapeutic strategies in men and women, with the goal of reducing the risk of HF development and improving patient outcome.

The effect of sex on door-to-balloon time in patients presenting with ST-elevation myocardial infarction and referred for primary percutaneous coronary intervention: A systematic review

Timely reperfusion using primary percutaneous coronary intervention (pPCI) is the cornerstone of acute ST-elevation myocardial infarction (STEMI) management. We conducted a systematic review to examine the effect of sex on door-to-balloon (D2B) time and symptom-to-balloon (S2B) time. We observed longer D2B times and S2B times in female patients presenting with STEMI and referred for pPCI when compared to male patients. Future work is required to try and elucidate and mitigate sex-based front-line treatment delays for female STEMI patients.

Appropriate use criteria for cardiovascular magnetic resonance imaging (CMR): SIC-SIRM position paper part 1 (ischemic and congenital heart diseases, cardio-oncology, cardiac masses and heart transplant)

Cardiac magnetic resonance (CMR) has emerged as new mainstream technique for the evaluation of patients with cardiac diseases, providing unique information to support clinical decision-making. This document has been developed by a joined group of experts of the Italian Society of Cardiology and Italian society of Radiology and aims to produce an updated consensus statement about the current state of technology and clinical applications of CMR. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac radiology. Part 1 of the document will cover ischemic heart disease, congenital heart disease, cardio-oncology, cardiac masses and heart transplant.

Co-morbidities and co-medications as confounders of cardioprotection-Does it matter in the clinical setting?

The translation of cardioprotection from robust experimental evidence to beneficial clinical outcome for patients suffering acute myocardial infarction or undergoing cardiovascular surgery has been largely disappointing. The present review attempts to critically analyse the evidence for confounders of cardioprotection in patients with acute myocardial infarction and in patients undergoing cardiovascular surgery. One reason that has been proposed to be responsible for such lack of translation is the confounding of cardioprotection by co-morbidities and co-medications. Whereas there is solid experimental evidence for such confounding of cardioprotection by single co-morbidities and co-medications, the clinical evidence from retrospective analyses of the limited number of clinical data is less robust. The best evidence for interference of co-medications is that for platelet inhibitors to recruit cardioprotection per se and thus limit the potential for further protection from myocardial infarction and for propofol anaesthesia to negate the protection from remote ischaemic conditioning in cardiovascular surgery. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc.

Cardiovascular disease in women: insights from magnetic resonance imaging

The presentation and identification of cardiovascular disease in women pose unique diagnostic challenges compared to men, and underrecognized conditions in this patient population may lead to clinical mismanagement.This article reviews the sex differences in cardiovascular disease, explores the diagnostic and prognostic role of cardiovascular magnetic resonance (CMR) in the spectrum of cardiovascular disorders in women, and proposes the added value of CMR compared to other imaging modalities. In addition, this article specifically reviews the role of CMR in cardiovascular diseases occurring more frequently or exclusively in female patients, including Takotsubo cardiomyopathy, connective tissue disorders, primary pulmonary arterial hypertension and peripartum cardiomyopathy. Gaps in knowledge and opportunities for further investigation of sex-specific cardiovascular differences by CMR are also highlighted.

MRI for measuring therapy efficiency after revascularisation in ST-segment elevation myocardial infarction: a systematic review and meta-regression analysis

OBJECTIVE

To summarise existing data on the relation between the time from symptom onset until revascularisation (time to reperfusion) and the myocardial salvage index (MSI) calculated as proportion of non-necrotic myocardium inside oedematous myocardium on T2-weighted and T1-weighted late gadolinium enhancement MRI after ST-segment elevation myocardial infarction (STEMI).

METHODS

Studies including patients with revascularised STEMI and stating both the time to reperfusion and the MSI measured by T2-weighted and T1-weighted late gadolinium enhancement MRI were searched in MEDLINE, EMBASE and ISI Web of Science until 16 May 2020. A mixed effects model was used to evaluate the relation between the time to reperfusion and the MSI. The gender distribution and mean age in included patient groups, the timing of MRI, used MRI sequences and image interpretation methodology were included in the mixed effects model to explore between-study heterogeneity.

RESULTS

We included 38 studies with 5106 patients. The pooled MSI was 42.6% (95% CI: 38.1 to 47.1). The pooled time to reperfusion was 3.8 hours (95% CI: 3.5 to 4.0). Every hour of delay in reperfusion was associated with an absolute decrease of 13.1% (95% CI: 11.5 to 14.6; p<0.001) in the MSI. Between-study heterogeneity was considerable (σ²=167.8). Differences in the gender distribution, timing of MRI and image interpretation among studies explained 45.2% of the between-study heterogeneity.

CONCLUSIONS

The MSI on T2-weighted and T1-weighted late gadolinium enhancement MRI correlates inversely with the time to reperfusion, which indicates that cardioprotection achieved by minimising the time to reperfusion leads to a higher MSI. The analysis revealed considerable heterogeneity between studies. The heterogeneity could partly be explained by differences in the gender distribution, timing and interpretation of MRI suggesting that the MRI-assessed MSI is not only influenced by cardioprotective therapy but also by patient characteristics and MRI parameters.

Left ventricular remodelling after ST-segment elevation myocardial infarction: sex differences and prognosis

Aims

Left ventricular (LV) remodelling after ST‐segment elevation myocardial infarction (STEMI) worsens outcome. The effect of sex on LV post‐infarct remodelling is unknown. We therefore investigated the sex distribution and long‐term prognosis of LV post‐infarct remodelling after STEMI in the contemporary era of primary percutaneous coronary intervention (PCI) and optimal pharmacotherapy.

Methods and results

Data were obtained from an ongoing primary PCI STEMI registry. LV remodelling was defined as ≥20% increase in LV end‐diastolic volume at either 3, 6, or 12 months post‐infarct, and LV remodelling impact on outcome was evaluated with a log‐rank test. A total population of 1995 STEMI patients were analysed (mean age 60 ± 12 years): 1527 (77%) men and 468 (23%) women. The mean age of male patients was 60±11 versus 63±13 years for women (P < 0.001). A total of 953 (48%) patients experienced LV remodelling in the first 12 months of follow‐up, and it was equally frequent amongst men (n = 729, 48%) and women (n = 224, 48%). After a median follow‐up of 94 (interquartile range 69–119) months, 225 patients died: 171 (11%) men and 54 (12%) women. No survival difference was seen between remodellers and non‐remodellers in the male (P = 0.113) and female (P = 0.920) groups.

Conclusion

LV post‐infarct remodelling incidence, as well as long‐term survival of LV remodellers and non‐remodellers, was similar in men and women who were treated with primary PCI and optimal pharmacotherapy post‐STEMI.

Mitochondrial connexin 43 in sex-dependent myocardial responses and estrogen-mediated cardiac protection following acute ischemia/reperfusion injury

Preserving mitochondrial activity is crucial in rescuing cardiac function following acute myocardial ischemia/reperfusion (I/R). The sex difference in myocardial functional recovery has been observed after I/R. Given the key role of mitochondrial connexin43 (Cx43) in cardiac protection initiated by ischemic preconditioning, we aimed to determine the implication of mitochondrial Cx43 in sex-related myocardial responses and to examine the effect of estrogen (17β-estradiol, E2) on Cx43, particularly mitochondrial Cx43-involved cardiac protection following I/R. Mouse primary cardiomyocytes and isolated mouse hearts (from males, females, ovariectomized females, and doxycycline-inducible Tnnt2-controlled Cx43 knockout without or with acute post-ischemic E2 treatment) were subjected to simulated I/R in culture or Langendorff I/R (25-min warm ischemia/40-min reperfusion), respectively. Mitochondrial membrane potential and mitochondrial superoxide production were measured in cardiomyocytes. Myocardial function and infarct size were determined. Cx43 and its isoform, Gja1-20k, were assessed in mitochondria. Immunoelectron microscopy and co-immunoprecipitation were also used to examine mitochondrial Cx43 and its interaction with estrogen receptor-α by E2 in mitochondria, respectively. There were sex disparities in stress-induced cardiomyocyte mitochondrial function. E2 partially restored mitochondrial activity in cardiomyocytes following acute injury. Post-ischemia infusion of E2 improved functional recovery and reduced infarct size with increased Cx43 content and phosphorylation in mitochondria. Ablation of cardiac Cx43 aggravated mitochondrial damage and abolished E2-mediated cardiac protection during I/R. Female mice were more resistant to myocardial I/R than age-matched males with greater protective role of mitochondrial Cx43 in female hearts. Post-ischemic E2 usage augmented mitochondrial Cx43 content and phosphorylation, increased mitochondrial Gja1-20k, and showed cardiac protection.

Gender but not diabetes, hypertension or smoking affects infarct evolution in ST-elevation myocardial infarction patients - data from the CHILL-MI, MITOCARE and SOCCER trials

BACKGROUND

Infarct evolution rate and response to acute reperfusion therapy may differ between patients, which is important to consider for accurate management and treatment of patients with ST-elevation myocardial infarction (STEMI). The aim of this study was therefore to investigate the association of infarct size and myocardial salvage with gender, smoking status, presence of diabetes or history of hypertension in a cohort of STEMI-patients.

METHODS

Patients (n = 301) with first-time STEMI from the three recent multi-center trials (CHILL-MI, MITOCARE and SOCCER) underwent cardiac magnetic resonance (CMR) imaging to determine myocardium at risk (MaR) and infarct size (IS). Myocardial salvage index (MSI) was calculated as MSI = 1-IS/MaR. Pain to balloon time, culprit vessel, trial treatments, age, TIMI grade flow and collateral flow by Rentrop grading were included as explanatory variables in the statistical model.

RESULTS

Women (n = 66) had significantly smaller MaR (mean difference: 5.0 ± 1.5% of left ventricle (LV), p < 0.01), smaller IS (mean difference: 5.1 ± 1.4% of LV, p = 0.03), and larger MSI (mean difference: 9.6 ± 2.8% of LV, p < 0.01) compared to men (n = 238). These differences remained significant when adjusting for other explanatory variables. There were no significant effects on MaR, IS or MSI for diabetes, hypertension or smoking.

CONCLUSIONS

Female gender is associated with higher myocardial salvage and smaller infarct size suggesting a pathophysiological difference in infarct evolution between men and women.

Sex-based associations with microvascular injury and outcomes after ST-segment elevation myocardial infarction

Objectives

We aimed to assess for sex differences in invasive parameters of acute microvascular reperfusion injury and infarct characteristics on cardiac MRI after ST-segment elevation myocardial infarction (STEMI).

Methods

Patients with STEMI undergoing emergency percutaneous coronary intervention (PCI) were prospectively enrolled. Index of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were measured in the culprit artery post-PCI. Contrast-enhanced MRI was used to assess infarct characteristics, microvascular obstruction and myocardial haemorrhage, 2 days and 6 months post-STEMI. Prespecified outcomes were as follows: (i) all-cause death/first heart failure hospitalisation and (ii) cardiac death/non-fatal myocardial infarction/urgent coronary revascularisation (major adverse cardiovascular event, MACE) during 5- year median follow-up.

Results

In 324 patients with STEMI (87 women, mean age: 61 ± 12.19 years; 237 men, mean age: 59 ± 11.17 years), women had anterior STEMI less often, fewer prescriptions of beta-blockers at discharge and higher baseline N-terminal pro-B-type natriuretic peptide levels (all p < 0.05). Following emergency PCI, fewer women than men had Thrombolysis in Myocardial Infarction (TIMI) myocardial perfusion grades ≤ 1 (20% vs 32%, p = 0.027) and women had lower corrected TIMI frame counts (12.94 vs 17.65, p = 0.003). However, IMR, CFR, microvascular obstruction, myocardial haemorrhage, infarct size, myocardial salvage index, left ventricular remodelling and ejection fraction did not differ significantly between sexes. Female sex was not associated with MACE or all-cause death/first heart failure hospitalisation.

Conclusion

There were no sex differences in microvascular pathology in patients with acute STEMI. Women had less anterior infarcts than men, and beta-blocker therapy at discharge was prescribed less often in women.

Trial registration number

NCT02072850.

Microvascular obstruction extent predicts major adverse cardiovascular events in patients with acute myocardial infarction and preserved ejection fraction

OBJECTIVES

To investigate the prognostic role of early post-infarction cardiac magnetic resonance (CMR) on long-term risk stratification of ST segment elevation myocardial infarction (STEMI) patients with preserved left ventricular ejection fraction (LVEF).

METHODS

Seventy-seven STEMI patients treated by primary percutaneous coronary intervention (PCI) and LVEF > 50% at CMR were included. The median time between STEMI and CMR was 5 days (IQR 2-8). LV volumes and function, area at risk (on T2 weighted images), infarcted myocardium (on late enhanced images), intramyocardial hemorrhage, and early and late microvascular obstruction (MVO) were detected and measured. CMR tissue determinants were correlated with the incidence of major adverse cardiovascular events (MACEs) over a 5-year follow-up.

RESULTS

During median follow-up of 4 years (range 3 to 5 years), eight (10%) patients experienced MACE, yielding an annualized event rate of 2.1%. All CMR tissue markers were not significantly different between MACE and no-MACE patients, except for the presence of late MVO (50% vs. 16%, respectively; p = 0.044) and its extent (2.30 ± 1.64 g vs. 0.18 ± 0.12 g, respectively; p = 0.000). From receiver-operating characteristic (ROC) curve (area under the curve 0.89; 95% confidence interval, 0.75-1.0; p = 0.000), late MVO extent > 0.385 g was a strong independent predictor of MACE at long-term follow-up (sensitivity = 87%, specificity = 90%; hazard ratio = 2.24; 95% confidence interval, 1.51-3.33; p = 0.000).

CONCLUSIONS

Late MVO extent after primary PCI on CMR seems to be a strong predictor of MACE at 5-year follow-up in patients with LVEF > 50%. Noticeably, late MVO extent > 0.385 g provided relevant prognostic insights leading to improved long-term risk stratification.

KEY POINTS

• Tissue markers provided by cardiac magnetic resonance aid in prognostic stratification after myocardial infarction • The occurrence of late microvascular obstruction after acute myocardial infarction increases risk of major adverse events at 5-year follow-up. • The greater microvascular obstruction extent on late gadolinium enhanced images is related to an increased risk of adverse events in patients with myocardial infarction and preserved left ventricular function.

Prognosis-based definition of left ventricular remodeling after ST-elevation myocardial infarction

Objectives

Cardiac magnetic resonance (CMR) is the gold-standard modality for the assessment of left ventricular (LV) remodeling in ST-elevation myocardial infarction (STEMI) patients. However, the commonly used remodeling criteria have never been validated for hard clinical events. We therefore aimed to define clear CMR criteria of LV remodeling following STEMI with proven prognostic impact.

Methods

This observational study included 224 patients suffering from acute STEMI. CMR was performed within 1 week and 4 months after infarction to evaluate different remodeling criteria including relative changes in LV end-diastolic volume (%∆LVEDV), end-systolic volume (%∆LVESV), ejection fraction (%∆LVEF), and myocardial mass (%∆LVMM). Primary endpoint was the occurrence of major adverse cardiovascular events (MACE) including all-cause death, re-infarction, stroke, and new congestive heart failure 24 months following STEMI. Secondary endpoint was defined as composite of primary endpoint and cardiovascular hospitalization. The Mann–Whitney U test was applied to assess differences in LV remodeling measures between patients with and without MACE. Values for the prediction of primary and secondary endpoints were assessed by c-statistics and Cox regression analysis.

Results

The incidence of MACE (n = 13, 6%) was associated with higher %∆LVEDV (p = 0.002) and %∆LVMM (p = 0.02), whereas %∆LVESV and %∆LVEF were not significantly related to MACE (p > 0.05). The area under the curve (AUC) for the prediction of MACE was 0.76 (95% confidence interval [CI], 0.65–0.87) for %∆LVEDV (optimal cut-off 10%) and 0.69 (95%CI, 0.52–0.85) for %∆LVMM (optimal cut-off 5%). From all remodeling criteria, %∆LVEDV ≥ 10% showed highest hazard ratio (8.68 [95%CI, 2.39–31.56]; p = 0.001) for MACE. Regarding secondary endpoint (n = 35, 16%), also %∆LVEDV with an optimal threshold of 10% emerged as strongest prognosticator (AUC 0.66; 95%CI, 0.56–0.75; p = 0.004).

Conclusions

Following revascularized STEMI, %∆LVEDV ≥ 10% showed strongest association with clinical outcome, suggesting this criterion as preferred CMR-based definition of post-STEMI LV remodeling.

Key Points

• CMR-determined %∆LVEDV and %∆LVMM were significantly associated with MACE following STEMI.

• Neither %∆LVESV nor %∆LVEF showed a significant relation to MACE.

• %∆LVEDV ≥ 10 was revealed as LV remodeling definition with highest prognostic validity.

Infarct size, left ventricular function, and prognosis in women compared to men after primary percutaneous coronary intervention in ST-segment elevation myocardial infarction: results from an individual patient-level pooled analysis of 10 randomized trials

Aim

Studies have reported less favourable outcomes in women compared with men after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). Whether sex-specific differences in the magnitude or prognostic impact of infarct size or post-infarction cardiac function explain this finding is unknown.

Methods and results

We pooled patient-level data from 10 randomized primary PCI trials in which infarct size was measured within 1 month (median 4 days) by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. We assessed the association between sex, infarct size, and left ventricular ejection fraction (LVEF) and the composite rate of death or heart failure (HF) hospitalization within 1 year. Of 2632 patients with STEMI undergoing primary PCI, 587 (22.3%) were women. Women were older than men and had a longer delay between symptom onset and reperfusion. Infarct size did not significantly differ between women and men, and women had higher LVEF. Nonetheless, women had a higher 1-year rate of death or HF hospitalization compared to men, and while infarct size was a strong independent predictor of 1-year death or HF hospitalization (P < 0.0001), no interaction was present between sex and infarct size or LVEF on the risk of death or HF hospitalization.

Conclusions

In this large-scale, individual patient-level pooled analysis of patients with STEMI undergoing primary PCI, women had a higher 1-year rate of death or HF hospitalization compared to men, a finding not explained by sex-specific differences in the magnitude or prognostic impact of infarct size or by differences in post-infarction cardiac function.

Survival kinase-dependent pathways contribute to gender difference in the response to myocardial ischemia-reperfusion and ischemic post-conditioning

The response to ischemia/reperfusion and the effects of ischemic post-conditioning (IPC) are sex-dependent, but the mechanisms have not been clarified. Male (M) and female (F) rat hearts isolated and perfused using the Langendorff technique were subject to 30 min of global ischemia (GI) and 60 min reperfusion (R). In IPC hearts, three cycles of 30-sec GI/30-sec R were applied at the beginning of R. Infarct size and myocardial function were assessed. Superoxide production, antioxidant systems, and expressions of phosphorylated forms of serine/threonine kinase (Akt), glycogen synthase kinase 3β (GSK-3β), protein kinase C ε (PKCε), endothelial nitric oxide synthase (eNOS), and apoptosis were measured. In the basal state, superoxide production and apoptosis were lower, and antioxidant systems and phospho-kinase expressions were higher in F rather than in M hearts. After ischemia-reperfusion, infarct size was less in F hearts, and post-ischemic recovery of myocardial function was higher in F rather than in M hearts. Superoxide production, phospho-kinase activity, phospho-eNOS, and apoptosis increased in both sexes while antioxidants decreased in both sexes. After IPC, infarct size, superoxide production, and apoptosis decreased and phospho-eNOS increased in F and M hearts but phospho-kinase expressions and post-ischemic recovery of myocardial function improved only in M hearts. These results show that Akt/GSK-3β/PKCε/eNOS-dependent pathways-mediated superoxide production and apoptosis appear as important factors involved in the observed gender differences.

TIME Trial: Effect of Timing of Stem Cell Delivery Following ST-Elevation Myocardial Infarction on the Recovery of Global and Regional Left Ventricular Function: Final 2-Year Analysis

RATIONALE

The TIME trial (Timing in Myocardial Infarction Evaluation) was the first cell therapy trial sufficiently powered to determine if timing of cell delivery after ST-segment-elevation myocardial infarction affects recovery of left ventricular (LV) function.

OBJECTIVE

To report the 2-year clinical and cardiac magnetic resonance imaging results and their modification by microvascular obstruction.

METHODS AND RESULTS

TIME was a randomized, double-blind, placebo-controlled trial comparing 150 million bone marrow mononuclear cells versus placebo in 120 patients with anterior ST-segment-elevation myocardial infarctions resulting in LV dysfunction. Primary end points included changes in global (LV ejection fraction) and regional (infarct and border zone) function. Secondary end points included changes in LV volumes, infarct size, and major adverse cardiac events. Here, we analyzed the continued trajectory of these measures out to 2 years and the influence of microvascular obstruction present at baseline on these long-term outcomes. At 2 years (n=85), LV ejection fraction was similar in the bone marrow mononuclear cells (48.7%) and placebo groups (51.6%) with no difference in regional LV function. Infarct size and LV mass decreased ≥30% in each group at 6 months and declined gradually to 2 years. LV volumes increased ≈10% at 6 months and remained stable to 2 years. Microvascular obstruction was present in 48 patients at baseline and was associated with significantly larger infarct size (56.5 versus 36.2 g), greater adverse LV remodeling, and marked reduction in LV ejection fraction recovery (0.2% versus 6.2%).

CONCLUSIONS

In one of the longest serial cardiac magnetic resonance imaging analyses of patients with large anterior ST-segment-elevation myocardial infarctions, bone marrow mononuclear cells administration did not improve recovery of LV function over 2 years. Microvascular obstruction was associated with reduced recovery of LV function, greater adverse LV remodeling, and more device implantations. The use of cardiac magnetic resonance imaging leads to greater dropout of patients over time because of device implantation in patients with more severe LV dysfunction resulting in overestimation of clinical stability of the cohort.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00684021.

Optimization of large animal MI models; a systematic analysis of control groups from preclinical studies

Large animal models are essential for the development of novel therapeutics for myocardial infarction. To optimize translation, we need to assess the effect of experimental design on disease outcome and model experimental design to resemble the clinical course of MI. The aim of this study is therefore to systematically investigate how experimental decisions affect outcome measurements in large animal MI models. We used control animal-data from two independent meta-analyses of large animal MI models. All variables of interest were pre-defined. We performed univariable and multivariable meta-regression to analyze whether these variables influenced infarct size and ejection fraction. Our analyses incorporated 246 relevant studies. Multivariable meta-regression revealed that infarct size and cardiac function were influenced independently by choice of species, sex, co-medication, occlusion type, occluded vessel, quantification method, ischemia duration and follow-up duration. We provide strong systematic evidence that commonly used endpoints significantly depend on study design and biological variation. This makes direct comparison of different study-results difficult and calls for standardized models. Researchers should take this into account when designing large animal studies to most closely mimic the clinical course of MI and enable translational success.

Cardiovascular magnetic resonance imaging assessment of outcomes in acute myocardial infarction

Cardiovascular magnetic resonance (CMR) imaging uniquely characterizes myocardial and microvascular injury in acute myocardial infarction (AMI), providing powerful surrogate markers of outcomes. The last 10 years have seen an exponential increase in AMI studies utilizing CMR based endpoints. This article provides a contemporary, comprehensive review of the powerful role of CMR imaging in the assessment of outcomes in AMI. The theory, assessment techniques, chronology, importance in predicting left ventricular function and remodelling, and prognostic value of each CMR surrogate marker is described in detail. Major studies illustrating the importance of the markers are summarized, providing an up to date review of the literature base in CMR imaging in AMI.

A protective role of early collateral blood flow in patients with ST-segment elevation myocardial infarction

Conflict persists regarding whether the presence of early collateral blood flow to the infarct-related artery has an effective role in reducing infarct size and improving myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI). We sought to investigate the impact of the collateral circulation on myocardial salvage and infarct size in STEMI patients.

METHODS

In 306 patients who were diagnosed with STEMI and underwent cardiac magnetic resonance within 1 week after revascularization, initial collateral flow to the infarct-related artery was assessed by coronary angiography. Using cardiac magnetic resonance imaging, myocardial infarct size and salvage were measured.

RESULTS

Among 247 patients with preprocedural Thrombolysis in Myocardial Infarction flow 0/1, 54 (22%) patients had good collaterals (Rentrop grade ≥ 2, Collateral Connection Score ≥ 2). Infarct size and area at risk were significantly smaller in patients with good collaterals than those with poor collaterals (infarct size: 17.1 ± 10.1 %LV vs 21.8 ± 10.5 %LV, P = .003, area at risk: 33.8 ± 16.8 %LV vs 38.8 ± 15.5 %LV, P = .039). There was a significant difference of myocardial salvage index between 2 groups (50.9% ± 15.0% vs 43.8% ± 18.5%, P = .005). Poor collateralization was an independent predictor for large infarct size (odd ratio 2.48 [1.28-4.80], P = .007).

CONCLUSIONS

In patients with STEMI, the presence of well-developed collaterals to occluded coronary artery from the noninfarct vessel and its extent were independently associated with reduced infarct burden and improved myocardial salvage. Our results help explain why MI patients with well-developed collateralization have reduced mortality and morbidity.

Impact of Heart Rate on Myocardial Salvage in Timely Reperfused Patients with ST-Segment Elevation Myocardial Infarction: New Insights from Cardiovascular Magnetic Resonance

BACKGROUND

Previous studies evaluating the progression of the necrotic wave in relation to heart rate were carried out only in animal models of ST-elevated myocardial infarction (STEMI). Aim of the study was to investigate changes of myocardial salvage in relation to different heart rates at hospital admission in timely reperfused patients with STEMI by using cardiovascular magnetic resonance (CMR).

METHODS

One hundred-eighty-seven patients with STEMI successfully and timely treated with primary coronary angioplasty underwent CMR five days after hospital admission. According to the heart rate at presentation, patients were subcategorized into 5 quintiles: <55 bpm (group I, n = 44), 55-64 bpm (group II, n = 35), 65-74 bpm (group III, n = 35), 75-84 bpm (group IV, n = 37), ≥85 bpm (group V, n = 36). Area at risk, infarct size, microvascular obstruction (MVO) and myocardium salvaged index (MSI) were assessed by CMR using standard sequences.

RESULTS

Lower heart rates at presentation were associated with a bigger amount of myocardial salvage after reperfusion. MSI progressively decreased as the heart rates increased (0.54 group I, 0.46 group II, 0.38 group III, 0.34 group IV, 0.32 group V, p<0.001). Stepwise multivariable analysis showed heart rate, peak troponin and the presence of MVO were independent predictor of myocardial salvage. No changes related to heart rate were observed in relation to area at risk and infarct size.

CONCLUSIONS

High heart rates registered before performing coronary angioplasty in timely reperfused patients with STEMI are associated with a reduction in salvaged myocardium. In particular, salvaged myocardium significantly reduced when heart rate at presentation is ≥85 bpm.

Interaction of risk factors, comorbidities, and comedications with ischemia/reperfusion injury and cardioprotection by preconditioning, postconditioning, and remote conditioning

Pre-, post-, and remote conditioning of the myocardium are well described adaptive responses that markedly enhance the ability of the heart to withstand a prolonged ischemia/reperfusion insult and provide therapeutic paradigms for cardioprotection. Nevertheless, more than 25 years after the discovery of ischemic preconditioning, we still do not have established cardioprotective drugs on the market. Most experimental studies on cardioprotection are still undertaken in animal models, in which ischemia/reperfusion is imposed in the absence of cardiovascular risk factors. However, ischemic heart disease in humans is a complex disorder caused by, or associated with, cardiovascular risk factors and comorbidities, including hypertension, hyperlipidemia, diabetes, insulin resistance, heart failure, altered coronary circulation, and aging. These risk factors induce fundamental alterations in cellular signaling cascades that affect the development of ischemia/reperfusion injury per se and responses to cardioprotective interventions. Moreover, some of the medications used to treat these risk factors, including statins, nitrates, and antidiabetic drugs, may impact cardioprotection by modifying cellular signaling. The aim of this article is to review the recent evidence that cardiovascular risk factors and their medication may modify the response to cardioprotective interventions. We emphasize the critical need to take into account the presence of cardiovascular risk factors and concomitant medications when designing preclinical studies for the identification and validation of cardioprotective drug targets and clinical studies. This will hopefully maximize the success rate of developing rational approaches to effective cardioprotective therapies for the majority of patients with multiple risk factors.

Does sex influence the incidence or severity of reperfusion-induced cardiac arrhythmias?

Whether sex affects the acute phase of myocardial ischemia in experimental animal models is currently being debated. Our purpose was to determine if sex influences either the incidence or severity of reperfusion-induced arrhythmias resulting from a brief coronary occlusion. Male and female Sprague–Dawley rats were assigned to the study. Anesthetized animals were subjected to a 5-minute coronary artery occlusion followed by 5 minutes of reperfusion. Mortality differed by sex: 10/27 (37%) of males died due to VT/VF while only 1/16 females (6%) died due to VT/VF (p = 0.033). Quantitative analysis of the electrocardiogram was performed on data acquired from 17 male and 15 female survivors. Analysis showed no other significant differences in ventricular arrhythmias between the two groups. Conclusion: Lethal reperfusion-induced arrhythmias led to a higher mortality in male rats versus female rats. Among survivors there was no difference in any other arrhythmic parameters measured.

ESC working group cellular biology of the heart: position paper: improving the preclinical assessment of novel cardioprotective therapies

Ischaemic heart disease (IHD) remains the leading cause of death and disability worldwide. As a result, novel therapies are still needed to protect the heart from the detrimental effects of acute ischaemia–reperfusion injury, in order to improve clinical outcomes in IHD patients. In this regard, although a large number of novel cardioprotective therapies discovered in the research laboratory have been investigated in the clinical setting, only a few of these have been demonstrated to improve clinical outcomes. One potential reason for this lack of success may have been the failure to thoroughly assess the cardioprotective efficacy of these novel therapies in suitably designed preclinical experimental animal models. Therefore, the aim of this Position Paper by the European Society of Cardiology Working Group Cellular Biology of the Heart is to provide recommendations for improving the preclinical assessment of novel cardioprotective therapies discovered in the research laboratory, with the aim of increasing the likelihood of success in translating these new treatments into improved clinical outcomes.

High osteoprotegerin levels predict MACCE in STEMI patients, but are not associated with myocardial salvage

OBJECTIVES

High circulating levels of osteoprotegerin (OPG) carry prognostic impact in cohorts with various cardiovascular diagnoses. With the present study, we aim to investigate the role of OPG within the scale of myocardial damage.

DESIGN

This study includes 219 consecutive patients with acute ST-elevation myocardial infarction randomized to primary percutaneous coronary intervention (pPCI) or pPCI and remote ischemic per-conditioning. Salvage index via myocardial single-photon emission CT assessment (data available in 61% of the patients) was performed, and derived from Day 1 (myocardial area at risk) and Day 30 (final infarct size). Plasma OPG levels were measured using an in-house immunoassay. A combined end-point of all-mortality, myocardial infarction, stroke, readmission for heart failure and ischemic stroke/transient ischemic attack (Major Adverse Cardiac and Cerebrovascular Events [MACCE]) was used for follow-up; 45 (38-48 months).

RESULTS

High OPG levels were associated with the severity of cardiovascular disease. During follow-up, OPG was a predictor of MACCE (unadjusted, HR: 2.1, 95% CI: 1.14-3.85, P = 0.017). Adjustments for age, gender, and body mass index preserved the independent predictive power of OPG. However, OPG levels were neither associated with salvage index nor with the final infarct size. Remote ischemic per-conditioning had no effect on OPG levels.

CONCLUSION

Despite absent association between OPG levels and the scale of myocardial damage, high OPG levels predict a significantly increased risk of MACCE.

Implications of myocardial reperfusion on survival in women versus men with acute myocardial infarction undergoing primary coronary intervention

We evaluated the effects of myocardial perfusion after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) on gender-based mortality rates. Research has demonstrated a gender-specific response of cardiomyocytes to ischemia and a potential increase in myocardial salvage in women compared with men. Myocardial blush grade (MBG), an angiographic surrogate of myocardial perfusion, is an independent predictor of early and late survival after AMI. Whether the incidence and prognosis of myocardial perfusion differs according to gender among patients with AMI undergoing PCI is unknown. MBG and short- and long-term mortality were evaluated in 1,301 patients (male = 935; female = 366) with AMI randomized to primary angioplasty ± abciximab versus stent ± abciximab. Following PCI, >96% of patients achieved final Thrombolysis In Myocardial Infarction 3 flow, of which MBG 2/3 was present in 58.3% of women versus 51.1% of men (p = 0.02). Worse MBG was an independent predictor of mortality in women at 30 days (7.4% for MBG 0/1 vs 2.4% for MBG 2/3, p = 0.04) and at 1-year (11.0% for MBG 0/1 vs 3.4% for MBG 2/3, p = 0.01); however, MBG was not associated with differences in mortality for men. In conclusion, impaired myocardial perfusion following PCI for AMI, indicated by worse MBG, is an independent predictor of early and late mortality in women but not in men. These findings imply an enhanced survival benefit from restoring myocardial perfusion for women compared with men during primary angioplasty and may have clinical implications for interventional strategies in women.

Cardiac hemodynamics in men versus women during acute ST-segment elevation myocardial infarction

Several biologic and clinical factors contribute to the increased 30-day mortality and re-infarction rate in women with ST-segment elevation myocardial infarction (STEMI). Sex differences in cardiac hemodynamic parameters such as pulmonary capillary wedge pressure (PCWP) have not been examined and might play an important role. The objectives of the present study were to examine whether female sex is an independent determinant of PCWP during acute STEMI and whether an elevated PCWP contributes to all-cause 30-day mortality and re-infarction in women. The clinical, angiographic, and hemodynamic features of 470 consecutive patients with STEMI (n = 135 women) undergoing emergency coronary angiography with right-side heart catheterization were evaluated with respect to sex. Women had an elevated PCWP (20 ± 8 vs 16 ± 7 mm Hg, p <0.001) and reduced mixed venous oxygen saturation (67 ± 11% vs 71 ± 9%, p = 0.004). On multivariate analysis, female sex (β = 4.04, 95% confidence interval [CI] 2.04 to 6.04, p <0.001), hypertension (β = 2.07, 95% CI 0.31 to 3.83, p = 0.021), and creatine kinase-estimated infarct size (β = 0.001, 95% CI 0.001 to 0.002, p ≤0.001) were independent predictors of an elevated PCWP. Female sex exerted a minor independent effect on 30-day mortality and re-infarction (odds ratio 2.36, 95% CI 1.25 to 4.46, p = 0.008). However, once PCWP was entered into the mediation model, sex was no longer significant, suggesting that the effect of sex on the post-STEMI outcomes is potentially mediated through PCWP (odds ratio 1.07, 95% CI 1.02 to 1.12, p = 0.011). In conclusion, during acute STEMI, women have greater left ventricular filling pressures compared with men, independent of age, hypertension, and infarct size. The biologic explanation for this difference requires additional investigation, although it does not appear to contribute to the increased 30-day mortality and re-infarction rate observed in women.

The year 2012 in the European Heart Journal-Cardiovascular Imaging: Part I

The new multi-modality cardiovascular imaging journal, European Heart Journal - Cardiovascular Imaging, was started in 2012. During its first year, the new Journal has published an impressive collection of cardiovascular studies utilizing all cardiovascular imaging modalities. We will summarize the most important studies from its first year in two articles. The present 'Part I' of the review will focus on studies in myocardial function, myocardial ischaemia, and emerging techniques in cardiovascular imaging.

Relation of gender to infarct size in patients with ST-segment elevation myocardial infarction undergoing primary angioplasty

Previous reports have shown that female gender is associated with impaired outcomes among patients with ST-segment elevation myocardial infarction (STEMI) treated by thrombolysis, mainly owing to a worst risk profile (more diabetes, more advanced age, and higher Killip class at presentation) compared to men. Still contrasting are data on the effect of gender on the outcome in patients with STEMI undergoing primary angioplasty. In particular, it is still unclear whether a larger infarct size might contribute to the explanation of the worse outcome in women. Therefore, the aim of the present study was to investigate gender-related differences in infarct size as evaluated by myocardial scintigraphy in a large cohort of patients with STEMI undergoing primary percutaneous coronary intervention. We included 830 patients with STEMI undergoing primary percutaneous coronary intervention. The infarct size was evaluated at 30 days using technetium-99m-sestamibi. A logistic regression analysis was performed to determine the relation between gender and infarct size (as percentage of patients above the median) after correction for baseline confounding factors. We also evaluated the presence of a potential age-gender interaction. A total of 183 patients (20.8%) were women. Female gender was associated with more advanced age and a greater prevalence of hypertension; previous infarction and smoking were more frequently observed in men. Female gender was associated with a smaller infarct size (p <0.001) that was confirmed after correction for baseline confounding factors (adjusted odds ratio 0.48, 95% confidence interval 0.33-0.7, p <0.001). No age-gender interaction was observed (p = 0.13). In conclusion, the results of the present study have shown that despite the presence of high-risk features at presentation, female gender was associated with a smaller infarct size than that in men, without any interaction between age and gender.

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 [4, 6] days after the acute event. [corrected]. 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.