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Background:Right ventricular (RV) function is a known predictor of adverse events in heart failure and following acute myocardial infarction (AMI). While right atrial (RA) involvement is well characterized in pulmonary arterial hypertension, its relative contributions to adverse events following AMI especially in patients with heart failure and congestion needs further evaluation.Methods:1235 MI patients underwent CMR after primary percutaneous coronary intervention (PCI) in 15 centers across Germany (n=795 with ST-elevation MI and 440 with non ST-elevation MI). Right atrial (RA) performance was evaluated using cardiac magnetic resonance myocardial feature tracking (CMR-FT) for the assessment of RA reservoir (total strain ?s), conduit (passive strain ?e), booster pump function (active strain ?a) and associated strain rates (SR) in a blinded core-laboratory. The primary clinical endpoint was the occurrence of major adverse cardiac events (MACE) 12 months post MI.Results:RA reservoir (?sp=0.061, SRs p=0.049) and conduit functions (?ep=0.006, SRe p=0.030) were impaired in patients with MACE as opposed to RA booster pump (?ap=0.579, SRa p=0.118) and RA volume index (p=0.866). RA conduit function was associated with clinical onset of heart failure and MACE independently of RV systolic function (multi-variable analysis HR 0.95, 95% CI 0.91-0.99, p=0.006) while RV systolic function was no independent prognosticator (HR 0.98, 95% CI 0.96-1.00, p=0.055). Furthermore, RA conduit strain identified low- and high-risk groups within patients with relatively preserved and reduced RV and LV systolic functions (p<0.019 on log rank testing).Conclusions:Right atrial impairment is a distinct feature and independent risk factor in patients following AMI and can be easily assessed using CMR-FT derived quantification of RA strain.

Introduction:Despite limitations as a standalone parameter, left ventricular ejection fraction (LVEF) is the preferred measure of myocardial function and marker for post-infarction risk stratification.Hypothesis:Assessment of LV myocardial uniformity alterations may provide superior prognostic information after acute myocardial infarction (AMI), which was subject of this study.Methods:Consecutive patients with AMI (n=1082; median age 63 years; 75% male) undergoing cardiac magnetic resonance (CMR) in median 3 days after infarction were included in this multicenter, observational study. Circumferential and radial uniformity ratio estimates (CURE and RURE) were derived from CMR feature-tracking as markers of mechanical uniformity alterations (values between 0 and 1 with 1 reflecting perfect uniformity). The clinical endpoint was the 12-month rate of major adverse cardiac events (MACE), consisting of all-cause death, re-infarction, and new congestive heart failure.Results:Patients with MACE (n=73) had significantly impaired CURE [0.76 (IQR 0.67-0.86) versus 0.84 (IQR 0.76-0.89); p<0.001] and RURE [0.69 (IQR 0.60-0.79) versus 0.76 (IQR 0.67-0.83); p<0.001] compared to patients without events. While uniformity estimates did not provide independent prognostic information in the overall cohort, CURE below the median of 0.84 emerged as an independent predictor of outcome in post-infarction patients with LVEF >35% (n=959) even after adjustment for established prognostic markers (hazard ratio 1.99; 95% confidence interval 1.06-3.74; p=0.033 in stepwise multivariable Cox regression analysis). In contrast, LVEF was not associated with adverse events in this subgroup of AMI patients.Conclusions:CMR-derived estimates of mechanical uniformity alterations are novel markers for risk assessment after AMI and CURE provides independent prognostic information in patients with preserved or only moderately reduced LVEF.

Objective:Type 2 diabetes mellitus (T2DM) associates with worse cardiovascular outcome following acute myocardial infarction (AMI) as compared to non-diabetic patients. Since the mechanisms behind these observations are not fully understood we aimed to quantify the underlying pathophysiology on ventricular and atrial levels and study their prognostic implications using cardiovascular magnetic resonance (CMR) quantitative feature-tracking (FT) and tissue characterization.Research Design and Methods:A total of 1147 consecutive patients with AMI (n=265 with diabetes; n=882 without diabetes) undergoing cardiac magnetic resonance (CMR) imaging in median 3 days after AMI were included in this multicenter study. Left ventricular (LV) function and volumetry included LV ejection fraction (LV-EF), global longitudinal (GLS), radial (GRS) and circumferential strain (GCS) as well as left atrial (LA) strain and strain rate parameters of LA reservoir, conduit and booster pump function. LV damage assessment included infarct size (IS), edema and microvascular obstruction (MO). The clinical study endpoint was the rate of major adverse cardiovascular events (MACE) at 12 months.Results:T2DM patients had impaired LA reservoir (19.8 vs. 21.2%, p<0.01) and conduit strains 7.6 vs. 9.0%, p<0.01) but no differences in ventricular function or myocardial damage. They were at higher risk of MACE than non-diabetic patients (10.2% vs. 5.8%, p < 0.01) with the majority of MACE occurring in patients with LVEF ? 35%. Whilst LVEF was an independent predictor of adverse events in non-diabetic patients (p=0.04 on multivariable analysis), LV GLS as well as LA strain emerged as independent predictors of poor prognosis in patients with diabetes (p<0.02 on multivariable analysis). Considering patients with diabetes and LVEF ?35% (n=237), GLS and LA reservoir strain below median were significantly associated with higher 12-month event rates.Conclusions:In patients with diabetes, LA and LV longitudinal strain permit optimized risk assessment early after reperfused AMI with incremental prognostic value over and above LVEF.

Background:Prognosis in acute myocardial infarction (AMI) depends on the amount of infarct related artery (IRA) subtended myocardium and associated damage but has not been described in great detail. Consequently, we sought to describe IRA associated pathophysiological consequences using cardiac magnetic resonance (CMR).Methods:1235 AMI patients (n=795 ST-elevation (STEMI) and 440 non-STEMI) underwent CMR following percutaneous coronary intervention. Blinded core-laboratory data were compared according to left anterior descending (LAD), left circumflex (LCx) and right coronary artery (RCA) regarding major adverse clinical events (MACE) within 12 months. Left ventricular (LV) global longitudinal/circumferential/radial (GLS/GCS/GRS) as well as left atrial (LA) total (?s), passive (?e) and active (?a) strains were determined using CMR-feature tracking. Tissue characterisation included infarct size (IS) and microvascular obstruction.Results:LAD and LCx were associated with higher mortality compared to RCA lesions (4.6% and 4.4% vs 1.6%). LAD lesions showed largest IS (16.8%), largest ventricular (LV ejection fraction (EF) 47.4%, GLS -13.2%, GCS -20.8%) and atrial (?s 20.2%) impairment. There was less impairment in LCx (IS 11.8%, LVEF 50.8%, GLS -17.4%, GCS -25.0%, ?s 20.7%) followed by RCA lesions (IS 11.3%, LVEF 50.8%, GLS -19.1%, GCS -26.6%, ?s 21.7%). In AUC analyses ?s (LAD, RCA) and GLS (LCx) best predicted MACE (AUC>0.69). Multivariate analyses identified ?s (p=0.017) in LAD and GLS (p=0.034) in LCx infarcts as independent predictors of MACE.Conclusions:CMR allows IRA specific phenotyping and characterisation of morphologic and functional changes. These alterations carry infarct specific prognostic implications and may represent novel diagnostic and therapeutic targets following AMI.