Risk assessment of post-myocardial infarction patients with preserved ejection fraction using 45-min short resting Holter electrocardiographic recordings.

BACKGROUND: Risk stratification for sudden cardiac death in post-myocardial infarction (post-MI) patients remains a challenging task. Several electrocardiographic noninvasive risk factors (NIRFs) have been associated with adverse outcomes and were used to refine risk assessment. This study aimed to evaluate the performance of NIRFs extracted from 45-min short resting Holter ECG recordings (SHR), in predicting ventricular tachycardia inducibility with programmed ventricular stimulation (PVS) in post-MI patients with preserved left ventricular ejection fraction (LVEF). METHODS: We studied 99 post-MI ischemia-free patients (mean age: 60.5 ± 9.5 years, 86.9% men) with LVEF ≥40%, at least 40 days after revascularization. All the patients underwent PVS and a high-resolution SHR. The following parameters were evaluated: mean heart rate, ventricular arrhythmias (premature ventricular complexes, couplets, tachycardias), QTc duration, heart rate variability (HRV), deceleration capacity, heart rate turbulence, late potentials, and T-wave alternans. RESULTS: PVS was positive in 24 patients (24.2%). HRV, assessed by the standard deviation of normal-to-normal R-R intervals (SDNN), was significantly decreased in the positive PVS group (42 ms vs. 51 ms, p = .039). SDNN values <50 ms were also associated with PVS inducibility (OR 3.081, p = .032 in univariate analysis, and 4.588, p = .013 in multivariate analysis). No significant differences were identified for the other NIRFs. The presence of diabetes, history of ST-elevation MI (STEMI) and LVEF <50% were also important predictors of positive PVS. CONCLUSIONS: HRV assessed from SHR, combined with other noninvasive clinical and echocardiographic variables (diabetes, STEMI history, LVEF), can provide an initial, practical, and rapid screening tool for arrhythmic risk assessment in post-MI patients with preserved LVEF.

Three-dimensional echocardiographic assessment of left ventricular geometric changes following acute myocardial infarction.

Acute ST-segment elevation myocardial infarction (STEMI) is associated with left ventricular (LV) structural and functional consequences. We aimed to elucidate LV geometric changes following STEMI using three-dimensional (3D) echocardiography (3DE) and to assess their functional implications using two-dimensional (2D) speckle tracking echocardiography (STE). The study included 71 patients with STEMI who underwent baseline and 6-month follow-up 2D- and 3DE. Measured parameters included LV dimensions, biplane volumes, wall motion assessment, 2D LV global longitudinal strain (GLS), and 3D LV volumes, sphericity index and systolic dyssynchrony index. According to 3DE, LV geometric changes were classified as, adverse remodeling, reverse remodeling, and minimal LV volumetric changes. The occurrence of in-hospital and follow-up major adverse cardiovascular events (MACE) was assessed among the study population. The incidence of developing adverse remodeling was 25.4% while that of reverse remodeling was 36.6%. Adverse remodeling patients had significantly higher in-hospital MACE. Reverse remodeling was associated with significantly improved GLS, that was less evident in those with minimal LV geometric changes, and non-significant improvement for adverse remodeling group. LV baseline 2D GLS significantly correlated with follow-up 3D volumes among both reverse and adverse remodeling groups. Female gender and higher absolute GLS change upon follow-up were significantly associated with reverse remodeling. ROC-derived cutoff for adverse remodeling reallocated a substantial number of patients from the minimal change group to the adverse remodeling. Following acute STEMI, two-dimensional GLS was associated with and potentially predictive of changes in LV volumes as detected by three-dimensional echocardiography.

THE PROGNOSTIC UTILITY OF LEUKOCYTE AND PLATELET COUNTS FOR RISK ASSESSMENT OF IN-HOSPITAL COMPLICATIONS IN PATIENTS WITH ACUTE ST-SEGMENT ELEVATION MYOCARDIAL INFARCTION.

OBJECTIVE: The aim: We have aimed to develop method of risk assessment in patients with acute STEMI using blood cells count useful in everyday clinical practice. PATIENTS AND METHODS: Materials and methods: 317 STEMI patients admitted to ICCU starting at 01/2014 to 06/2020 were included in this study. Data were evaluated partially retrospectively (n=214), 1st group) and prospectively, applying new risk-assessment tool in 103 patients 2nd group). Study groups did not differ in terms of all clinical characteristics. RESULTS: Results: To evaluate criteria of severity of in-hospital complication we have created in-hospital complication index (HCI), composed according to number of adverse events per patient. Based on correlation analyses we have composed complex WBC-platelets (WBC-PLT) index = ((GRA - MON) / LYM) · 10 + PDWc + P-LCR). In the 1st study group WBC-PLT index was associated with in-hospital complications' index and correlated with neutrophil-leukocytes ratio (NLR) (p<0,001 and p<0,0005 respectively). WBC-PLT index > 137 appeared to be mildly associated with increased risk of adverse in-hospital outcomes (with specificity of 78 % and low sensitivity of 64 %, AUC- 0,72). Further prospective study of WBC-PLT index measured on the first STEMI-day (group 2) revealed that this parameter was more informative regarding association with adverse in-hospital events whereas NLR had low accuracy in risk assessment. CONCLUSION: Conclusions: WBC-PLT index assessed on the first STEMI day may be used as a tool for detection of patients at risk of adverse in-hospital events in the every-day clinical practice.

Cardiogenic Shock Complicating ST-Segment Elevation Myocardial Infarction: An 18-Year Analysis of Temporal Trends, Epidemiology, Management, and Outcomes.

BACKGROUND: There are limited data on the temporal trends, incidence, and outcomes of ST-segment-elevation myocardial infarction-cardiogenic shock (STEMI-CS). METHODS: Adult (>18 years) STEMI-CS admissions were identified using the National Inpatient Sample (2000-2017) and classified by tertiles of admission year (2000-2005, 2006-2011, 2012-2017). Outcomes of interest included temporal trends, acute organ failure, cardiac procedures, in-hospital mortality, hospitalization costs, and length of stay. RESULTS: In ∼4.3 million STEMI admissions, CS was noted in 368,820 (8.5%). STEMI-CS incidence increased from 5.8% in 2000 to 13.0% in 2017 (patient and hospital characteristics adjusted odds ratio [aOR] 2.45 [95% confidence interval {CI} 2.40-2.49]; P < 0.001). Multiorgan failure increased from 55.5% (2000-2005) to 74.3% (2012-2017). Between 2000 and 2017, coronary angiography and percutaneous coronary intervention use increased from 58.8% to 80.1% and 38.6% to 70.6%, whereas coronary artery bypass grafting decreased from 14.9% to 10.4% (all P < 0.001). Over the study period, the use of intra-aortic balloon pump (40.6%-37.6%) decreased, and both percutaneous left ventricular assist devices (0%-12.9%) and extra-corporeal membrane oxygenation (0%-2.8%) increased (all P < 0.001). In hospital mortality decreased from 49.6% in 2000 to 32.7% in 2017 (aOR 0.29 [95% CI 0.28-0.31]; P < 0.001). During the 18-year period, hospital lengths of stay decreased, hospitalization costs increased and use of durable left ventricular assist device /cardiac transplantation remained stable (P > 0.05). CONCLUSIONS: In the United States, incidence of CS in STEMI has increased 2.5-fold between 2000 and 2017, while in-hospital mortality has decreased during the study period. Use of coronary angiography and PCI increased during the study period.

Practical Assessment of the Tradeoff between Fatal Bleeding and Coronary Thrombotic Risks using the Academic Research Consortium for High Bleeding Risk Criteria.

AIMS: We aimed to establish a practical method for the assessment of tradeoff between thrombotic and bleeding risks. METHODS: We aimed to investigate the balance between bleeding risk and coronary thrombotic risk according to the number of the Academic Research Consortium for high bleeding risk (ARC-HBR) criteria in the multicenter prospective ST/non-ST elevation myocardial infarction (STEMI/NSTEMI) registry (N=12,093). Patients were divided as follows by the number of ARC-HBR criteria fulfilled: group 0, 0 major with ≤ 1 minor (N=6,792); group 1, 1 major with 0 minor (N=1,705); group 2, 0 major with ≥ 2 minors (N=790); group 3, 1 major with ≥ 1 minor (N=1,709); group 4, 2 majors with ≥ 0 minors (N=861); and group 5, ≥ 3 majors with ≥ 0 minor (N=236). We assessed the acute-phase absolute risk differences between bleeding and coronary thrombotic events in each group. RESULTS: At 7-day follow-up, all patients (groups 0-5) had a higher risk of major bleeding than that of any myocardial infarction (MI). Patients at ARC-HBR (groups 1-5) had a balanced risk between fatal MI and fatal bleeding, whereas patients at non-ARC-HBR (group 0) had a higher risk of fatal MI than that of fatal bleeding. CONCLUSIONS: All STEMI/NSTEMI patients have a relatively high risk of major bleeding as compared with the risk of any MI in the acute phase. The ARC-HBR criteria would be a practical tool for assessing the tradeoff between fatal bleeding and fatal MI risks. This practical assessment would be helpful for the optimal decision-making of appropriate treatment strategy considering the balance between bleeding and coronary thrombotic risks.

Neutrophil Gelatinase-Associated Lipocalin for the Assessment of Reversible versus Persistent Renal Tubular Damage in ST-Segment Myocardial Infarction Patients.

BACKGROUND: Most studies investigated the value of neutrophil gelatinase-associated lipocalin (NGAL) as a marker of renal tubular injury only at a single time point. We investigated the possible utilization of NGAL level dynamics for the identification of different renal injury patterns in ST-elevation myocardial infarction (STEMI) patients. METHODS: Blood samples for plasma NGAL in 132 STEMI patients were drawn immediately before and 24 h following primary coronary intervention. Abnormal elevation of NGAL levels was defined using the cardiac surgery-associated NGAL score with NGAL levels ≥100 ng/mL suggesting renal tubular damage. According to NGAL levels at 0 and 24 h, patients were stratified into 3 groups: no tubular damage (NGAL <100 ng/mL in both exams), reversible tubular damage (NGAL >100 ng/mL at 0 h but <100 ng/mL at 24 h), and persistent tubular damage (NGAL >100 ng/mL at both 0 and 24 h). RESULTS: Mean age was 62 ± 13 years, and 78% were men. Of these patients, 29/132 (22%) demonstrated reversible tubular damage, and 36/132 (27%) persistent tubular damage. Only 13/132 patients (10%) progressed to clinical acute kidney injury during hospitalization, all of whom had persistent tubular injury. In multivariate regression model, symptom duration was independently associated with persistent tubular damage, both as continues variable (odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01-1.04; p = 0.04) and for symptom duration >360 min (OR 2.66, 95% CI 1.07-6.63; p = 0.03). CONCLUSIONS: Renal tubular damage is common among STEMI patients. Dynamic NGAL measurement may differentiate between reversible and persistent tubular damage. Further trials are needed in order to assess the complex cardiorenal interactions.

Effect of drug-eluting stents on 1-year risk of new-onset atrial fibrillation in patients with acute myocardial infarction treated with percutaneous coronary intervention.

The use of a drug-eluting stent (DES) in patients with acute myocardial infarction (AMI) treated with percutaneous coronary intervention is conventional. However, the effect of DES on new-onset atrial fibrillation (AF) after AMI still remains unclear.By using data from Taiwan's National Health Insurance Research Database, a total of 17,741 patients with ST-elevation myocardial infarction (STEMI) and 17,631 patients with non-ST-elevation myocardial infarction (NSTEMI) treated with percutaneous coronary intervention were analyzed to investigate the risk of new-onset AF after index admission of AMI.There were 26.5% (N = 4696) of patients with STEMI and 39.5% (N = 6967) of patients with NSTEMI received DES implantation. Upon 1-year follow-up, we observed that DES placement was associated with a reduced 1-year risk of new-onset AF in the patients with NSTEMI (adjusted hazard ratio [aHR] = 0.74, 95% confidence interval [CI] = 0.59-0.93, P = .009) after adjustment for clinical relevant variables. This benefit was consistent with that in the patients with NSTEMI who were ≥75 years old, had a CHA2DS2-VASc score of ≥2, and did not receive intra-aortic balloon pump insertion (aHR = 0.72, 95% CI = 0.53-0.98, P = .039; aHR = 0.73, 95% CI = 0.586-0.92, P = .006; and aHR = 0.71, 95% CI = 0.56-0.90, P = .004; respectively). However, DES placement had a neutral effect on the risk of new-onset AF in the patients with STEMI.Compared with the use of BMS, the use of DES might reduce the risk of new-onset AF in patients with NSTEMI.

Delay in coronary artery bypass grafting for STEMI patients improves hospital morbidity and mortality.

OBJECTIVES: The optimal timing of coronary artery bypass grafting (CABG) in patients with ST elevated acute myocardial infarction (STEMI) is unclear. The purpose of the study is to evaluate and compare the outcomes in STEMI patients who underwent CABG within the various time intervals within the first 7 days of either emergent or urgent hospital admission. METHODS: Patients aged 30 years old and older diagnosed with STEMI who underwent CABG within first 7 days after non-elective hospital admission were selected from the National Inpatient Sample 2010-2014 using the appropriate ICD-9-CM diagnosis and procedure codes. These patients were divided into 3 cohorts based on timing of surgery: within 24 h (group A), 2nd-3rd day (group B), and 4th-7th day (group C). The rates of postoperative complications, mortality, and postoperative hospital length of stay (LOS) were compared using the Chi-square test, multivariable logistic regression analysis, and Wilcoxon rank sum test. RESULTS: A total of 5963 patients were identified: group A = 28.5%, group B = 36.1%, group C = 35.4%. Mean age overall was 63.1 ± 11.1 years; 76.9% were males and 72.9% were whites. Compared to groups B and C, patients in group A were more likely to develop cardiac complications (OR [odds ratio] =1.33, 95%CI [confidence interval] 1.12-1.59 and OR = 1.39, 95%CI 1.17-1.67, respectively) and respiratory complications (OR = 1.31, 95%CI 1.13-1.51 and OR = 1.53, 95%CI 1.32-1.78, respectively). They were also more likely to have renal complications (OR = 1.31, 95%CI 1.11-1.54) and bleeding (OR = 1.20, 95%CI 1.05-1.37) than patients in group B and had a similar tendency compared to group C. We did not find significant differences in the above complications between groups B and C. Postoperative stroke and sternal wound infection rates were similar between all three groups. In-hospital mortality was also higher in group A (8.2%) compared to group B (3.5%) and group C (2.9%, P < 0.0001 for both); differences between groups B and C were not significant. This was confirmed in the multivariable logistic regression analysis with controlling for age, gender, race, the Elixhauser Comorbidity Index, and complications (group A vs B: OR = 1.85, 95%CI 1.52-2.25; group A vs C: OR = 2.21; 95%CI 1.82-2.68). Patients in group A had a significantly longer postoperative LOS (median 7 days with IQR [interquartile range] 5-10 days) compared to those in group B (median 6 days, IQR 5-8 days) and group C (median 6 days, IQR 4-8 days; P < 0.0001 for both). CONCLUSIONS: The results of this study show that despite the urgency and severity of STEMI, patients who undergo CABG within the first 24 h after non-elective hospital admission have increased hospital morbidity and mortality. These findings suggest that a delay in surgery beyond the first 24 h may be beneficial to patient outcomes. Furthermore, there is a significant cost effectiveness when the patients delay surgery because the hospital length of stay is reduced as well as the subsequent hospital costs.

Regional Variation in Procedural and Clinical Outcomes Among Patients With ST Elevation Myocardial Infarction With Cardiogenic Shock.

There is limited data on regional differences in patient characteristics, practice patterns, and clinical outcomes in patients with ST elevation myocardial infarction (STEMI) with cardiogenic shock (CS) in the United States (US). We aimed to identify variations in treatment methods and clinical outcomes in patients with STEMI CS between the 4 US regions. Using the National Inpatient Sample database, we identified adult patients admitted with STEMI associated with CS between 2006 and 2015 using ICD-9-DM codes. Based on the US regions (Northeast, Midwest, South, and West), we divided patients in 4 cohorts and compared baseline patient characteristics, clinical outcomes and procedural outcomes. A total of 186,316 patients with STEMI CS were included; 32,303 (17.3%) were hospitalized in the Northeast, 43,634 (23.4%) in the Midwest, 70,036 (37.8%) in the South, and 40,043 (21.5%) in the West. Although nonstatistically significant, the in-hospital mortality was higher in Northeast region (37.7%), followed by the South (36.6%), West (35.7%), and Midwest (35.2%). Rates of percutaneous coronary intervention were higher in the Midwest (68.5%) and lower in the Northeast (56%). The use of percutaneous ventricular assist device and ECMO was higher in the Northeast (3.3% and 2.2%) and lower in the West (2.1% and 0.4%). The median length of stay was similar among all 4 cohorts (6 days) but median hospital costs were higher in the West ($36, 614) and lower in the South ($28,795). In conclusion, there are significant geographic variations in practice patterns, healthcare cost, and in-hospital outcomes in patients with STEMI complicated by CS between 4 US regions.

Reflectance spectral analysis for novel characterization and clinical assessment of aspirated coronary thrombi in patients with ST elevation myocardial infarction.

OBJECTIVE: The visual appearance of coronary thrombi may be clinically informative in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (pPCI). However, subjective assessment is poorly reproducible and cannot provide an objective basis for treatment decisions or patient stratification. We have assessed the feasibility of a novel reflectance spectroscopy technique to systematically characterize coronary artery thrombi retrieved by aspiration during pPCI in patients with STEMI, and the clinical utility for predicting distal microvascular obstruction. APPROACH: Patients with STEMI treated with pPCI and thrombus aspiration (n = 288) were recruited from the Oxford Acute Myocardial Infarction (OxAMI) Study. Of these, 158 patients underwent cardiac magnetic resonance imaging within 48 h for assessment of microvascular obstruction (MVO). Coronary thrombi were imaged by reflectance spectroscopy across wavelengths 500-800 nm. MAIN RESULTS: Spectral data were analysed using function fitting and multivariate models. The coefficient 'c red' determined from the fitting procedure correlated with the visually-assessed colour of thrombi ('red' or 'white') and with MVO. When applied to a reduced data set, consisting of spectra from 20 patients with the largest MVO and from 20 propensity-score-matched patients with no MVO, three multivariate analysis methods were able to discriminate spectra of thrombi from patients without MVO and with the largest MVO. SIGNIFICANCE: Reflectance spectral analysis of coronary thrombus provides new insights into the pathology of STEMI, with potential clinical implications for emergency patient care. Further studies are warranted for validation as a point-of-care stratification tool in predicting the degree of microvascular injury and clinical outcomes in STEMI.

Mitral annular plane systolic excursion by cardiac MR is an easy tool for optimized prognosis assessment in ST-elevation myocardial infarction.

OBJECTIVES: The purpose of this study was to assess the comparative prognostic value of mitral annular plane systolic excursion (MAPSE) versus left ventricular ejection fraction (LVEF), measured by cardiac magnetic resonance (CMR) imaging in patients with ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI). METHODS: CMR was performed in 255 STEMI patients within 2 days (interquartile range (IQR) 2-4 days) after infarction. CMR included MAPSE measurement on CINE 4-chamber view. Patients were followed for major adverse cardiovascular events (MACE)-death, non-fatal myocardial re-infarction, stroke, and new congestive heart failure. RESULTS: Patients with MACE (n = 35, 14%, median follow-up 3 years [IQR 1-4 years]) showed significantly lower MAPSE (8 mm [7-8.8] vs. 9.6 mm [8.1-11.5], p < 0.001). The association between decreased MAPSE (< 9 mm, optimal cut-off value by c-statistics) remained significant after adjustment for independent clinical and CMR predictors of MACE. The AUC of MAPSE for the prediction of MACE was 0.74 (CI 95% 0.65-0.82), significantly higher than that of LVEF (0.61 [CI 95% 0.50-0.71]; p < 0.001). CONCLUSIONS: Reduced long-axis function assessed with MAPSE measurement using CINE CMR independently predicts long-term prognosis following STEMI. Moreover, MAPSE provided significantly higher prognostic implication in comparison with conventional LVEF measurement. KEY POINTS: • MAPSE determined by CMR independently predicts long-term prognosis following STEMI. • MACE-free survival is significantly higher in patients with MAPSE ≥ 9 mm than < 9 mm. • MAPSE provides significantly higher prognostic implication than conventional LVEF.

Outcomes after STEMI in old multimorbid patients with complex health needs and the effect of invasive management.

BACKGROUND: The aim of this study was to assess one-year outcomes of invasive and non-invasive strategies in ST-elevation myocardial infarction (STEMI) among multimorbid older people with complex health needs. METHODS: We included patients, registered between 2006 and 2013 in the SWEDEHEART registry, who were 70 years old or older with STEMI, had multimorbidity and complex health needs and were discharged alive. The one-year outcomes of patients who underwent invasive strategy (examined with coronary angiography ≤14 days) were compared to those who did not. The primary event was a composite of all-cause death, admission due to new acute coronary syndrome, stroke or transient ischemic attack. RESULTS: We identified patients, and 1089 were managed invasively and 570 non-invasively. The mean age was 79 years and 83 years in the 2 groups, respectively. After multivariable adjustment for baseline differences between the groups, including propensity scores, the primary event occurred in 31% of patients in the invasive group and 55% in the non-invasive group, adjusted hazard ratio (95% confidence intervals): 0.67 (0.54-0.83). One-year mortality was 18% in the invasive group and 45% in the non-invasive group, adjusted hazard ratio 0.51 (0.39-0.65). CONCLUSIONS: Multimorbid older people with complex health needs and STEMI had high rates of new ischemic events and death. In this cohort of older, high risk STEMI patients, an invasive strategy was associated with lower event rates. Randomized studies are needed to clarify whether these high risk patients who might benefit from invasive care are being managed too conservatively.

Adding Speckle-Tracking Echocardiography to Visual Assessment of Systolic Wall Motion Abnormalities Improves the Detection of Myocardial Infarction.

BACKGROUND: The aim of this study was to investigate whether speckle-tracking echocardiography (STE) improves the detection of myocardial infarction (MI) over visual assessment of systolic wall motion abnormalities (SWMAs) using delayed enhancement cardiac magnetic resonance imaging as a reference. METHODS: Transthoracic echocardiography was performed in 95 patients with first ST segment elevation MI 110 days (interquartile range, 97-171 days) after MI and in 48 healthy control subjects. Two experienced observers independently assessed SWMAs. Separately, longitudinal peak negative, peak systolic, end-systolic, global strain, and strain rate were measured and averaged for the American Heart Association-recommended coronary artery perfusion territories. Receiver operating characteristic analysis was used to determine a single optimal cutoff value for each strain parameter. The diagnostic accuracy of an algorithm combining visual assessment and STE was evaluated. RESULTS: Median infarct size and transmurality were 15% (interquartile range, 7%-24%) and 64% (interquartile range, 46%-78%), respectively. Sensitivity, specificity, and accuracy of visual assessment to detect MI were 74% (95% CI, 63%-82%), 85% (95% CI, 72%-93%), and 78% (95% CI, 70%-84%), respectively. Among the strain parameters, SR had the highest diagnostic accuracy (area under the curve, 0.88; 95% CI, 0.83-0.94; cutoff value, -0.97 sec-1). The combination with STE improved sensitivity compared with visual assessment alone (94%; 95% CI, 86%-97%; P < .001), minimally affecting specificity (79%; 95% CI, 65%-89%; P = .607). Overall accuracy improved to 89% (95% CI, 82%-93%; P = .011). Multivariate analysis accounting for age and sex demonstrated that SR was independently associated with MI (odds ratio, 2.0; 95% CI, 1.6-2.7). CONCLUSIONS: The sensitivity and diagnostic accuracy of visually detecting chronic MI by assessing SWMAs are moderate but substantially improve when adding STE.

Cost assessment of treatment of acute myocardial infarction and angiographically visible coronary thrombus.

AIM: Study was aimed to assess the real-world costs of manual thrombectomy (MT) in selected ST-segment elevation myocardial infarction patients with intracoronary thrombus (IT). METHODS: Study group (IT+) comprised 51 patients with MT applied and control group (IT-) comprised 56 patients without IT who underwent angioplasty alone. Costs comprised hospital care and cost of disposable materials used during primary angioplasty. RESULTS: Complex management of patients with IT is more expensive, though allows to achieve clinical outcomes comparable to low-risk ST-segment elevation myocardial infarction patients without IT. CONCLUSION: A complex pharmaco-interventional strategy, with glycoprotein IIB/IIIA inhibitor and MT, though more expensive, may prove cost-effective.

Serial assessment of left ventricular morphology and function in a rodent model of ischemic cardiomyopathy.

Left ventricular remodelling (LVr) occurs post myocardial infarction (MI), predisposing people to heart failure (HF). LV mechanics and morphology are important in this process. We hence sort to characterize LV mechanics and geometry in a post-MI rodent model. Thirty-two male Sprague-Dawley rats (150-200 g) sustained MI (n = 24) or sham (Sham; n = 8) surgery. In another six sham rats invasive blood pressure measurements were performed. Ultrasound imaging was done at baseline, and 1, 3, 7, 14, 30 and 60 days following surgery, and LV mechanics and morphology assessed. LV volumes increased with time (p < 0.01), at a greater rate in the MI group than the Sham group (p < 0.01). Strain was impaired in MI rats at day 1 (13.50 ± 6.64 vs. 25.71 ± 4.94%, p < 0.01) and remained impaired at day 60 (14.07 ± 5.37 vs. 22.98 ± 5.87%, p < 0.01). Strain rate was lower at day 1 (4.11 ± 1.29 vs. 8.10 ± 2.18%/s, p < 0.01), remained lower throughout follow-up (p < 0.01), and decreased at a greater rate in MI rats (p < 0.01). Mean systolic (204 ± 43 vs. 322 ± 75 1/m, p < 0.01) and diastolic (167 ± 21 vs. 192 ± 11 1/m, p < 0.01) curvature was lower in the MI rats at day 1 post surgery and throughout follow-up (p < 0.01). Maximum principal curvature decreased throughout time (p < 0.01), while minimum principal curvature did not (p = 0.86). Wall stress increased significantly after infarction in MI rats (p < 0.01). ST-elevation myocardial infarction (STEMI) changed LV shape and contractile function. The assessment of these indices may prove useful in understanding LVr and the development of HF.

Optimized Prognosis Assessment in ST-Segment-Elevation Myocardial Infarction Using a Cardiac Magnetic Resonance Imaging Risk Score.

BACKGROUND: Cardiac magnetic resonance (CMR) demonstrated great potential for the prediction of major adverse cardiac events (MACE) in ST-segment-elevation myocardial infarction. The aim of this study was to develop and validate a CMR-based risk score for ST-segment-elevation myocardial infarction patients. METHODS AND RESULTS: The scoring model was developed and validated on ST-segment-elevation myocardial infarction cohorts from 2 independent randomized controlled trials (n=738 and n=458 patients, respectively) and included left ventricular (LV) ejection fraction, infarct size, and microvascular obstruction. Primary end point was the 12-month MACE rate consisting of death, reinfarction, and new congestive heart failure. In the derivation cohort, LV ejection fraction ≤47%, infarct size ≥19%LV, and microvascular obstruction ≥1.4%LV were identified as the best cutoff values for MACE prediction. According to the hazard ratios in multivariable regression analysis, the CMR risk score was created by attributing 1 point for LV ejection fraction ≤47%, 1 point for infarct size ≥19%LV, and 2 points for microvascular obstruction ≥1.4%LV. In the validation cohort, the score showed a good prediction of MACE (area under the curve: 0.76). Stratification into a low (0/1 point) and high-risk group (≥2 points) resulted in significantly higher MACE rates in high-risk patients (9.0% versus 2.2%; P=0.001). Inclusion of the CMR score in addition to a model of clinical risk factors led to a significant increase of C statistics from 0.74 to 0.83 (P=0.037), a net reclassification improvement of 0.18 (P=0.009), and an integrated discriminative improvement of 0.04 (P=0.010). CONCLUSIONS: Our approach integrates the prognostic information of CMR imaging into a simple risk score that showed incremental prognostic value over clinical risk factors in ST-segment-elevation myocardial infarction patients. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifiers: NCT00712101 and NCT02158468.

In vivo assessment of myocardial viability after acute myocardial infarction: A head-to-head comparison of the perfusable tissue index by PET and delayed contrast-enhanced CMR.

BACKGROUND: Early recognition of viable myocardium after acute myocardial infarction (AMI) is of clinical relevance, since affected segments have the potential of functional recovery. Delayed contrast-enhanced magnetic resonance imaging (DCE-CMR) has been validated extensively for the detection of viable myocardium. An alternative parameter for detecting viability is the perfusable tissue index (PTI), derived using [15O]H2O positron emission tomography (PET), which is inversely related to the extent of myocardial scar (non-perfusable tissue). The aim of the present study was to investigate the predictive value of PTI on recovery of LV function as compared to DCE-CMR in patients with AMI, after successful percutaneous coronary intervention (PCI). METHODS: Thirty-eight patients with ST elevation myocardial infarction (STEMI) successfully treated by PCI were prospectively recruited. Subjects were examined 1 week and 3 months (mean follow-up time: 97 ± 10 days) after AMI using [15O]H2O PET and DCE-CMR to assess PTI, regional function and scar. Viability was defined as recovery of systolic wall thickening ≥3.0 mm at follow-up by use of CMR. A total of 588 segments were available for serial analysis. RESULTS: At baseline, 180 segments were dysfunctional and exhibited DCE. Seventy-three (41%) of these dysfunctional segments showed full recovery during follow-up (viable), whereas 107 (59%) segments remained dysfunctional (nonviable). Baseline PTI of viable segments was 0.94 ± 0.09 and was significantly higher compared to nonviable segments (0.80 ± 0.13, P < .001). The optimal cut-off value for PTI was ≥0.85 with a sensitivity of 85% and specificity of 72%, and an area under the curve (AUC) of 0.82. In comparison, a cut-off value of <32% for the extent of DCE resulted in a sensitivity of 72% and a specificity of 69%, and an AUC of 0.75 (AUC PTI vs DCE P = .14). CONCLUSION: Assessment of myocardial viability shortly after reperfused AMI is feasible using PET. PET-derived PTI yields a good predictive value for the recovery of LV function in PCI-treated STEMI patients, in excellent agreement with DCE-CMR.

The role of left ventricular deformation in the assessment of microvascular obstruction and intramyocardial haemorrhage.

In the setting of acute ST-elevation myocardial infarction (STEMI), it remains unclear which strain parameter most strongly correlates with microvascular obstruction (MVO) or intramyocardial haemorrhage (IMH). We aimed to investigate the association of MVO, IMH and convalescent left ventricular (LV) remodelling with strain parameters measured with cardiovascular magnetic resonance (CMR). Forty-three patients with reperfused STEMI and 10 age and gender matched healthy controls underwent CMR within 3-days and at 3-months following reperfused STEMI. Cine, T2-weighted, T2*-imaging and late gadolinium enhancement (LGE) imaging were performed. Infarct size, MVO and IMH were quantified. Peak global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS) and their strain rates were derived by feature tracking analysis of LV short-axis, 4-chamber and 2-chamber cines. All 43 patients and ten controls completed the baseline scan and 34 patients completed 3-month scans. In multivariate regression, GLS demonstrated the strongest association with MVO or IMH (beta = 0.53, p < 0.001). The optimal cut-off value for GLS was -13.7% for the detection of MVO or IMH (sensitivity 76% and specificity 77.8%). At follow up, 17% (n = 6) of patients had adverse LV remodeling (defined as an absolute increase of LV end-diastolic/end-systolic volumes >20%). Baseline GLS also demonstrated the strongest diagnostic performance in predicting adverse LV remodelling (AUC = 0.79; 95% CI 0.60-0.98; p = 0.03). Post-reperfused STEMI, baseline GLS was most closely associated with the presence of MVO or IMH. Baseline GLS was more strongly associated with adverse LV remodelling than other CMR parameters.