Assessing myocardial recovery following ST-segment elevation myocardial infarction: short- and long-term perspectives using cardiovascular magnetic resonance

Prognostic value of depressed cardiac index after STEMI: a phase-contrast magnetic resonance study

AIMS 

An invasively measured cardiac index (CI) of ≤2.2 L/min/m2 is one of the strongest prognostic indicators after ST-elevation myocardial infarction (STEMI), however, knowledge is mainly based on invasive evaluations performed in the pre-stent era. Velocity-encoded phase-contrast cardiac magnetic resonance (PC-CMR) allows non-invasive determination of CI.

METHODS AND RESULTS 

In this prospective study, CMR was performed in 406 stable and contemporarily revascularized patients a median of 3 days after STEMI. Forward stroke volume was assessed at the level of the ascending aorta by PC-CMR. Left ventricular ejection fraction (LVEF) and global longitudinal strain (GLS) were determined by cine CMR. Major adverse cardiac events (MACE) were defined as the composite of death, myocardial infarction, or hospitalization for heart failure. Median CI was 2.52 L/min/m2 and 27% of patients had ≤2.2 L/min/m2. Median LVEF was 53% and median GLS was -12.2%. During a median follow-up of 14.2 [95% confidence interval (95% CI) 13.6-14.7] months, 41 patients (10.1%) experienced a MACE. A depressed CI was significantly associated with MACE after adjustment for LVEF, GLS, Thrombolysis in Myocardial Infarction (TIMI) risk score, and infarct size [hazard ratio = 3.15 (95% CI 1.53-6.47); P = 0.002] and led to significant discrimination improvement [net reclassification improvement 0.61 (95% CI 0.25-0.97); P < 0.001].

CONCLUSIONS 

A CI of 2.2 L/min/m2 or less as measured by PC-CMR was present in 27% of clinically stable patients after STEMI and strongly and independently predicted medium-term MACE. The prognostic value of a depressed CI was superior and incremental to LVEF, GLS, TIMI risk score, and infarct size.

Myocardial strain by cardiac magnetic resonance: A valuable predictor of outcome after infarct revascularization

PURPOSE

To evaluate the prognostic value of left ventricular strains by cardiac magnetic resonance feature tracking (CMR-FT) in patients with re-perfused myocardial infarction (MI).

METHODS

The study enrolled 58 patients with re-vascularized MI who underwent CMR within a week from acute MI. An 18-month follow-up was carried out for the composite endpoint of major adverse cardiovascular events (MACE). A 3 to 6-month post-MI ejection fraction (EF) was also measured. The predictive value of global longitudinal, circumferential, and radial strains (GLS, GCS, and GRS, respectively) for MACE and the follow-up EF was evaluated.

RESULTS

All the global strains showed significant impairment in MACE positive cases (P < 0.05 for all). On univariate regression, MACE was reversely associated with early post-MI EF (OR: 0.90, 95% CI: 0.83-0.98, P: 0.01), and directly associated with GLS (OR: 1.32, 95% CI: 1.03-1.69, P: 0.02), GCS (OR: 1.23, 95% CI: 1.00-1.50, P: 0.04) and EDVI (OR:1.02, 95 %CI: 1.00-1.04, P: 0.01). On multivariate regression model, only the interaction between EF and GLS showed a significant association with MACE (OR[CI95%]: 1.1 [1.06-1.21]). EF < 30% and GLS > -8.9% had the highest sensitivity (78.9% and 89.5%, respectively) and specificity (45.2% and 54.8%, respectively) to predict MACE. The combination of EF < 30% and GLS > -8.9% increased the sensitivity to 94.7%. In addition, the cutoff values of 35.1% for early post-MI EF and -10% for GLS could identify patients with impaired follow-up EF with more than 80% sensitivity and specificity [AUC (CI95%): 0.893(0.76-1.00) for EF and AUC (CI95%):0.836(0.67-1,00) for GLS, P < 0.05 for both)].

CONCLUSIONS

GLS by CMR-FT is a powerful prognosticator of MACE and functional recovery in MI survivors, with incremental value added to early post-MI EF alone.

Global longitudinal strain improves risk assessment after ST-segment elevation myocardial infarction: a comparative prognostic evaluation of left ventricular functional parameters

AIM

We aimed to investigate the comparative prognostic value of left ventricular ejection fraction (LVEF), mitral annular plane systolic excursion (MAPSE), fast manual long-axis strain (LAS) and global longitudinal strain (GLS) determined by cardiac magnetic resonance (CMR) in patients after ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This observational cohort study included 445 acute STEMI patients treated with primary percutaneous coronary intervention (pPCI). Comprehensive CMR examinations were performed 3 [interquartile range (IQR): 2-4] days after pPCI for the determination of left ventricular (LV) functional parameters and infarct characteristics. Primary endpoint was the occurrence of major adverse cardiac events (MACE) defined as composite of death, re-infarction and congestive heart failure. During a follow-up of 16 [IQR: 12-49] months, 48 (11%) patients experienced a MACE. LVEF (p = 0.023), MAPSE (p < 0.001), LAS (p < 0.001) and GLS (p < 0.001) were significantly related to MACE. According to receiver operating characteristic analyses, only the area under the curve (AUC) of GLS was significantly higher compared to LVEF (0.69, 95% confidence interval (CI) 0.64-0.73; p < 0.001 vs. 0.60, 95% CI 0.55-0.65; p = 0.031. AUC difference: 0.09, p = 0.020). After multivariable analysis, GLS emerged as independent predictor of MACE even after adjustment for LV function, infarct size and microvascular obstruction (hazard ratio (HR): 1.13, 95% CI 1.01-1.27; p = 0.030), as well as angiographical (HR: 1.13, 95% CI 1.01-1.28; p = 0.037) and clinical parameters (HR: 1.16, 95% CI 1.05-1.29; p = 0.003).

CONCLUSION

GLS emerged as independent predictor of MACE after adjustment for parameters of LV function and myocardial damage as well as angiographical and clinical characteristics with superior prognostic validity compared to LVEF.

Estimating the extent of myocardial damage in patients with STEMI using the DETERMINE score

Background

Recently, a simple ECG score (DETERMINE score) has been proposed for estimating myocardial scar in patients with ischaemic cardiomyopathy. We sought to evaluate the usefulness of the DETERMINE score for the assessment of myocardial infarct size (IS) as well as microvascular obstruction (MVO), in the setting of ST-elevation myocardial infarction (STEMI).

Methods

This observational study enrolled 423 patients with STEMI (median age 56, 17% women), revascularised by primary percutaneous coronary intervention (PCI). For evaluation of the DETERMINE and Selvester scoring system (an established but complex ECG score for IS estimation), ECG was conducted before discharge (median: 4 (IQR 2–6) days). Cardiac magnetic resonance (CMR) was conducted within a week after infarction for determination of IS and MVO.

Results

Median DETERMINE score of the overall cohort was 8 points (IQR 5–11). A higher DETERMINE score was significantly associated with a larger IS (21% vs 11% of left ventricular myocardial mass (LVMM), p<0.001) as well as larger MVO (1.2% vs 0.0% of LVMM, p<0.001). In linear and binary multivariable logistic regression analysis, the DETERMINE score remained independently associated with IS (OR 1.09, 95% CI 1.02 to 1.17, p=0.014) and MVO (OR 1.12, 95% CI 1.04 to 1.21, p=0.003), after adjustment for Selvester score and clinical indicators of IS (high-sensitivity cardiac troponin T, high-sensitivity C reactive protein, N-terminal pro-B-type natriuretic peptide, TIMI flow pre-interventional and post-interventional PCI, anterior infarct localisation).

Conclusions

In patients undergoing PCI for STEMI, the DETERMINE score provides an easy and inexpensive tool for appropriate estimation of infarct severity as determined by CMR.

High sensitivity C-reactive protein is associated with worse infarct healing after revascularized ST-elevation myocardial infarction

BACKGROUND

The inflammatory response due to myocardial tissue injury in the setting of acute ST-elevation myocardial infarction (STEMI) is essential for proper local infarct healing. However, an excessive inflammatory response may aggravate myocardial damage and hampers infarct healing processes. The present study aimed to investigate the association of systemic inflammatory biomarkers with infarct size (IS) dynamics post-STEMI, using cardiac magnetic resonance (CMR) imaging.

METHODS

This prospective observational study included 245 STEMI patients treated with primary percutaneous coronary intervention (pPCI). Peak values of high-sensitivity C-reactive protein (hs-CRP), white blood cell count (WBCc) and fibrinogen were determined serially until 96 h after pPCI. Infarct healing, defined as relative IS reduction from baseline to 4 months after STEMI, was assessed using late gadolinium enhanced CMR imaging.

RESULTS

IS significantly decreased from 16% of left ventricular mass (LVM) (Interquartile range [IQR]:8-24) at baseline to 10% (IQR:5-17) at 4 months (p < 0.001). Relative IS reduction was 35% (IQR:8-50). Whereas peak WBCc (p = 0.926) and peak fibrinogen (p = 0.161) were not significantly associated with relative IS reduction, peak hs-CRP showed a significant association with IS reduction (p = 0.003). In multivariable logistic regression analysis, the association between peak hs-CRP and relative IS reduction remained significant after adjustment for baseline IS, hypertension, hs-cardiac troponin T and N-terminal pro B-type natriuretic peptide (odds ratio:0.35 [95% confidence interval:0.19-0.63]; p = 0.001).

CONCLUSIONS

In STEMI patients treated with pPCI, hs-CRP was independently associated with 4 months IS reduction as determined by CMR, suggesting a pathophysiological interplay between inflammation and adverse infarct healing in survivors of acute STEMI.

Circulating miR-1 as a potential predictor of left ventricular remodeling following acute ST-segment myocardial infarction using cardiac magnetic resonance

Background

The identification of patients with a high likelihood of left ventricular (LV) remodeling with a high-risk prognosis has critical implications for risk stratification after acute ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the relationship between circulating miR-1 and 6-month post-infarct LV remodeling based on cardiac magnetic resonance (CMR) imaging.

Methods

A total of 80 patients with a first STEMI treated with primary percutaneous coronary intervention (PCI) who underwent CMR imaging 1 week and 6 months after STEMI were evaluated. The percentage changes of LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume index (LVESV) at 1 week and 6 months after PCI (%ΔLVEF, %ΔLVEDV and %ΔLVESV) were calculated. miR-1 was measured using polymerase chain reaction (PCR)-based technologies in plasma samples that were collected at admission. The study group was divided into two groups based on a 10% cutoff value for the percentage of change in the LV end-diastolic volume (%ΔLVEDV): remodeling at high risk of major adverse cardiac events (MACEs) (%ΔLVEDV ≥10%, termed the LV remodeling group) and remodeling at lower risk of MACEs (%ΔLVEDV <10%, termed the non-LV remodeling group). The associations of miR-1 expression with the %ΔLVEDV, percentage change in the LV end-systolic volume (%ΔLVESV), and percentage change in the LV ejection fraction at follow-up were estimated.

Results

Twenty-two patients (27.5%) showed adverse LV remodeling, and 58 patients (72.5%) did not show adverse LV remodeling at the 6-month follow-up of CMR. The mean LVEF, LVEDV index, and LVESV index values at 1 week were 50.6%±8.2%, 74.6±12.8 mL/m², and 37.2±10.2 mL/m², respectively. Mean LVEF at follow-up (53.5%±10.6%) was increased compared with baseline (P<0.001). There were significant decreases in LVEDV index and LVESV index values at follow-up (72.0±14.9 mL/m² and 33.7±11.0 mL/m², respectively; P=0.009 and P<0.001, respectively). The expression of miR-1 at admission was positively correlated with the %ΔLVEDV (r=0.611, P<0.001) and %ΔLVESV (r=0.268, P=0.016). Receiver operating characteristic (ROC) analysis showed that miR-1 expression predicted LV remodeling with an area under the curve (AUC) value of 0.68 (95% CI: 0.56-0.78). Compared with the clinical factors of peak creatine kinase-myocardial band (CK-MB) and peak troponin T level, peak logNT-proBNP showed the highest predictive power, with an AUC value of 0.75 (95% CI: 0.64-0.84). A model including the clinical, CMR, and miR-1 factors showed greater predictive power (P=0.034) than a model including only clinical and CMR factors, with AUCs of 0.89 (95% CI: 0.80-0.95) and 0.81 (95% CI: 0.71-0.89), respectively.

Conclusions

Circulating miR-1 at admission is an independent predictor of LV remodeling 6 months after STEMI. miR-1 showed incremental value in predicting LV remodeling compared with the clinical and CMR measurements.

Impact of Cardio-Ankle Vascular Index on Long-Term Outcome in Patients with Acute Coronary Syndrome

AIM

The purpose of this study is to investigate the impact of arterial stiffness assessed using Cardio-ankle Vascular Index (CAVI) on long-term outcome after acute coronary syndrome (ACS).

METHODS

A total of 387 consecutive patients (324 males; age, 64±11 years) with ACS were enrolled. We examined CAVI and brachial-ankle pulse wave velocity (ba PWV) as the parameters of arterial stiffness. The patients were divided into two groups according to the cut-off value of CAVI determined using the receiver operating characteristic curve for the prediction of major adverse cardiovascular events (MACE): low-CAVI group, 177 patients with CAVI ＜8.35; high-CAVI group, 210 patients with CAVI ≥ 8.35. The primary endpoint was the incidence of MACE (cardiovascular death, recurrence of ACS, heart failure requiring hospitalization, or stroke).

RESULTS

A total of 62 patients had MACE. Kaplan-Meier analysis demonstrated a significantly higher probability of MACE in the high-CAVI group than in the low-CAVI group (median follow-up: 62 months; log-rank, p＜0.001). Multivariate analysis suggested that CAVI was an independent predictor of MACE (hazard ratio [HR], 1.496; p=0.02) and cardiovascular death (HR, 2.204; p=0.025), but ba PWV was not. We investigated the incremental predictive value of adding CAVI to the GRACE score (GRS), a validated scoring system for risk assessment in ACS. Stratified by CAVI and GRS, a significantly higher rate of MACE was seen in patients with both higher CAVI and higher GRS than the other groups (p＜0.001). Furthermore, the addition of CAVI to GRS enhanced net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI, 0.337, p=0.034; and IDI, 0.028, p=0.004).

CONCLUSION

CAVI was an independent long-term predictor of MACE, especially cardiovascular death, adding incremental clinical significance for risk stratification in patients with ACS.

Global longitudinal strain by feature tracking for optimized prediction of adverse remodeling after ST-elevation myocardial infarction

BACKGROUND

The role of left ventricular (LV) myocardial strain by cardiac magnetic resonance feature tracking (CMR-FT) for the prediction of adverse remodeling following ST-elevation myocardial infarction (STEMI), as well as its prognostic validity compared to LV ejection fraction (LVEF) and CMR infarct severity parameters, is unclear. This study aimed to evaluate the independent and incremental value of LV strain by CMR-FT for the prediction of adverse LV remodeling post-STEMI.

METHODS

STEMI patients treated with primary percutaneous coronary intervention were enrolled in this prospective observational study. CMR core laboratory analysis was performed to assess LVEF, infarct pathology and LV myocardial strain. The primary endpoint was adverse remodeling, defined as ≥ 20% increase in LV end-diastolic volume from baseline to 4 months.

RESULTS

From the 232 patients included, 38 (16.4%) reached the primary endpoint. Global longitudinal strain (GLS), global radial strain, and global circumferential strain were all predictive of adverse remodeling (p < 0.01 for all), but only GLS was an independent predictor of adverse remodeling (odds ratio: 1.36[1.03-1.78]; p = 0.028) after adjustment for strain parameters, LVEF and CMR markers of infarct severity. A GLS > - 14% was associated with a fourfold increase in the risk for LV remodeling (odds ratio: 4.16[1.56-11.13]; p = 0.005). Addition of GLS to a baseline model comprising LVEF, infarct size and microvascular obstruction resulted in net reclassification improvement of 0.26 ([0.13-0.38]; p < 0.001) and integrated discrimination improvement of 0.02 ([0.01-0.03]; p = 0.006).

CONCLUSIONS

In STEMI survivors, determination of GLS using CMR-FT provides important prognostic information for the development of adverse remodeling that is incremental to LVEF and CMR markers of infarct severity.

CLINICAL TRIAL REGISTRATION

NCT04113356.

Depression and myocardial injury in ST-segment elevation myocardial infarction: A cardiac magnetic resonance imaging study

BACKGROUND

Depression is common in patients with myocardial infarction and has been independently associated with adverse outcomes. However, the association between depression and myocardial injury on cardiac magnetic resonance (CMR) in patients with ST-segment elevation myocardial infarction (STEMI) has still not been assessed.

AIM

To assess the association between depression and myocardial injury on CMR in patients with STEMI.

METHODS

A total of 107 STEMI patients undergoing primary percutaneous coronary intervention (P-PCI) were analyzed in this prospectivecohort study. Each subject completed the Patient Health Questionnaire-9 (PHQ-9) to assess the presence and severity of depressive symptoms. CMR was performed at a median of 3 d after P-PCI for quantifying post-MI myocardial injury. Correlations between depression identified by the PHQ-9 and myocardial injury measured on CMR were assessed.

RESULTS

In this study, 19 patients (17.8%) were diagnosed with major depression identified by the PHQ-9 ≥ 10. PHQ-9 was analyzed both as a continuous variable and dichotomous variable. After multivariable adjustment, the proportion of patients with large infarction size was significantly higher in the major depression group (PHQ-9 ≥ 10) (OR: 4.840, 95%CI: 1.122–20.868, P =0.034). When the PHQ-9 was evaluated as a continuous variable, after multivariable adjustment, an increased PHQ-9 score was associated with an increased risk of large infarction size (OR: 1.226, 95%CI: 1.073–1.401, P =0.003).

CONCLUSION

In patients with STEMI undergoing PCI, depression was independently associated with a large infarction size.

Aortic Stiffness and Infarct Healing in Survivors of Acute ST-Segment-Elevation Myocardial Infarction

Background

In survivors of acute ST‐segment–elevation myocardial infarction (STEMI), increased aortic stiffness is associated with worse clinical outcome; however, the underlying pathomechanisms are incompletely understood. We aimed to investigate associations between aortic stiffness and infarct healing using comprehensive cardiac magnetic resonance imaging in patients with acute STEMI.

Methods and Results

This was a prospective observational study including 103 consecutive STEMI patients treated with primary percutaneous coronary intervention. Pulse wave velocity (PWV), the reference standard for aortic stiffness assessment, was determined by a validated phase‐contrast cardiac magnetic resonance imaging protocol within the first week after STEMI. Infarct healing, defined as relative infarct size reduction from baseline to 4 months post‐STEMI, was determined using late gadolinium‐enhanced cardiac magnetic resonance. Median infarct size significantly decreased from 17% of left ventricular mass (interquartile range 9% to 28%) at baseline to 12% (6% to 17%) at 4‐month follow‐up (P<0.001). Relative infarct size reduction was 36% (interquartile range 15% to 52%). Patients with a reduction >36% were younger (P=0.01) and had lower baseline NT‐proBNP (N‐terminal pro–B‐type natriuretic peptide) concentrations (P=0.047) and aortic PWV values (P=0.003). In a continuous (odds ratio 0.64 [95% CI, 0.49–0.84]; P=0.001) as well as categorical (PWV <7 m/s; odds ratio 4.80 [95% CI, 1.89–12.20]; P=0.001) multivariable logistic regression model, the relation between aortic PWV and relative infarct size reduction remained significant after adjustment for baseline infarct size, age, NT‐proBNP, and C‐reactive protein.

Conclusions

Aortic PWV independently predicted infarct size reduction as assessed by cardiac magnetic resonance, revealing a novel pathophysiological link between aortic stiffness and adverse infarct healing during the early phase after STEMI treated with contemporary primary percutaneous coronary intervention.

Complete versus simplified Selvester QRS score for infarct severity assessment in ST-elevation myocardial infarction

Background

Complete and simplified Selvester QRS score have been proposed as valuable clinical tool for estimating myocardial damage in patients with ST-elevation myocardial infarction (STEMI). We sought to comprehensively compare both scoring systems for the prediction of myocardial and microvascular injury assessed by cardiac magnetic resonance (CMR) imaging in patients with acute STEMI.

Methods

In this prospective observational study, 201 revascularized STEMI patients were included. Electrocardiography was conducted at a median of 2 (interquartile range 1–4) days after the index event to evaluate the complete and simplified QRS scores. CMR was performed within 1 week and 4 months thereafter to determine acute and chronic infarct size (IS) as well as microvascular obstruction (MVO).

Results

Complete and simplified QRS score showed comparable predictive value for acute (area under the curve (AUC) = 0.64 vs. 0.67) and chronic IS (AUC = 0.63 vs. 0.68) as well as for MVO (AUC = 0.64 vs. 0.66). Peak high sensitivity cardiac troponin T (hs-cTnT) showed an AUC of 0.88 for acute IS and 0.91 for chronic IS, respectively. For the prediction of MVO, peak hs-cTnT represented an AUC of 0.81.

Conclusions

In reperfused STEMI, complete and simplified QRS score displayed comparable value for the prediction of acute and chronic myocardial as well as microvascular damage. However, both QRS scoring systems provided inferior predictive validity, compared to peak hs-cTnT, the clinical reference method for IS estimation.

Baseline LV ejection fraction by cardiac magnetic resonance and 2D echocardiography after ST-elevation myocardial infarction - influence of infarct location and prognostic impact

Objectives

The comparability of left ventricular ejection fraction (LVEF) measurements by cardiac magnetic resonance (CMR) and 2D echocardiography (2DE) early after ST-elevation myocardial infarction (STEMI) remains unclear.

Methods

In this study, LVEF measured by CMR and 2DE (Simpson’s method) were compared in 221 patients after STEMI treated by primary percutaneous coronary intervention. 2DE image quality was systematically assessed and studies reported by an accredited examiner. Intermodality agreement was assessed by the Bland–Altman method. Major adverse cardiac events (MACE) were defined as the composite of death, myocardial infarction or hospitalisation for heart failure. Patients were followed up for a median of 40.9 months (IQR 28.1–56).

Results

After non-anterior STEMI, LVEF measurements by 2DE (single and biplane) were consistently underestimated in comparison to CMR (CMR 55.7 ± 9.5% vs. 2DE-4CV 49 ± 8.2% (p = 0.06), 2DE-2CV 52 ± 8% (p < 0.001), 2DE-biplane 53.5 ± 7.1% (p = 0.01)). After anterior STEMI, there was no significant difference in LVEF measurements by 2DE and CMR with acceptable limits of agreement (CMR 49 ± 11% vs. 2DE-4CV 49 ± 8.2% (p = 0.8), 2DE-2CV 49 ± 9.2% (p = 0.9), 2DE-biplane 49.6 ± 8% (p = 0.5)). In total, 15% of patients experienced a MACE during follow-up. In multivariate Cox regression analysis, reduced LVEF (< 52%) as assessed by either 2DE or CMR was predictive of MACE (2DE HR = 2.57 (95% CI 1.1–6.2), p = 0.036; CMR HR = 2.51 (95% CI 1.1–5.7), p = 0.028).

Conclusions

At baseline after non-anterior STEMI, 2D echocardiography significantly underestimated LVEF in comparison to CMR, whereas after anterior infarction, measurements were within acceptable limits of agreement. Both imaging modalities offered similar prognostic values when a reduced LVEF < 52% was applied.

Key Points

• After non-anterior STEMI, 2D-echocardiography significantly underestimated LVEF compared with cardiac MRI

• An ejection fraction of < 52% in the acute post-infarct period by both 2D echocardiography and CMR offered similar prognostic values

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.

Biomarker assessment for early infarct size estimation in ST-elevation myocardial infarction

BACKGROUND

High-sensitivity cardiac troponin T (hs-cTnT) represents the biomarker of choice for infarct size (IS) estimation in patients with acute ST-elevation myocardial infarction (STEMI). However, admission values of hs-cTnT are only weakly associated with IS. The aim of this study was to investigate the incremental value of different biomarkers measured on admission for IS estimation in STEMI patients.

METHODS

In this prospective observational study, we included 161 consecutive STEMI patients treated with primary percutaneous coronary intervention (pPCI). The following biomarkers were assessed on admission: hs-cTnT, N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and neutrophil/lymphocyte ratio (NLR). IS was determined by cardiac magnetic resonance (CMR) imaging 3 (Interquartile range [IQR] 2 to 4) days after the index event.

RESULTS

Patients with large IS (>19% of left ventricular myocardium) showed significantly higher levels of admission hs-cTnT (399.6 vs. 53.4 ng/L, p < .001), NT-pro-BNP (140 vs. 86 ng/L, p = .008) and NLR (6.4 vs. 4.1, p < .001). The combination of hs-cTnT, NT-pro-BNP and NLR on admission resulted in a significantly higher area under the curve (0.78; 95% CI 0.704 to 0.838, (p = .01)) for the prediction of large IS than admission hs-cTnT alone (0.69; 95% CI 0.619 to 0.767).

CONCLUSIONS

In STEMI patients undergoing pPCI, a comprehensive biomarker approach on admission including hs-cTnT, NT-pro-BNP and NLR was significantly better for immediate infarct severity estimation as compared to hs-cTnT alone.

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.

Daily remote ischaemic conditioning following acute myocardial infarction: a randomised controlled trial

BACKGROUND

Remote ischaemic conditioning (rIC) is a cardioprotective tool which has shown promise in preclinical and clinical trials in the context of acute ischaemia. Repeated rIC post myocardial infarction may provide additional benefits which have not previously been tested clinically.

METHODS

The trial assessed the role of daily rIC in enhancing left ventricular ejection fraction (LVEF) recovery in patients with impaired LVEF (<45%) after ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (P-PCI). Patients were recruited from four UK hospitals and randomised to receive either 4 weeks of daily rIC or sham conditioning using the autoRIC Device (CellAegis) starting on day 3 post P-PCI. The primary endpoint was the improvement in LVEF over 4 months assessed by cardiac MRI (CMR). Seventy-three patients (38 cases, 35 controls) completed the study.

RESULTS

The treatment and control groups were well matched at baseline including for mean LVEF (42.8% vs 44.3% respectively, p=0.952). There was no difference in the improvement in LVEF over 4 months between the treatment and control groups (4.8%±7.8% vs 4.6%±5.9% respectively, p=0.924). No differences were seen in the secondary outcome measures including changes in infarct size and left ventricular end-diastolic and systolic volumes, major adverse cardiac and cerebral event, mean Kansas City Cardiomyopathy Questionnaire score and change in N-terminal pro-brain natriuretic peptide levels.

CONCLUSIONS

Daily rIC starting on day 3 and continued for 4 weeks following successful P-PCI for STEMI did not improve LVEF as assessed by CMR after 4 months when compared with a matched control group.

TRIAL REGISTRATION NUMBER

NCT0166461.

Thyroid-stimulating hormone and adverse left ventricular remodeling following ST-segment elevation myocardial infarction

BACKGROUND

Adverse left ventricular remodeling is one of the major determinants of heart failure and mortality in patients surviving ST-segment elevation myocardial infarction (STEMI). The hypothalamic-pituitary-thyroid axis is a key cardiovascular regulator; however, the relationship between hypothalamic-pituitary-thyroid status and post-STEMI left ventricular remodeling is unclear. We aimed to investigate the association between thyroid-stimulating hormone concentrations and the development of left ventricular remodeling following reperfused STEMI.

METHODS

In this prospective observational study of 102 consecutive STEMI patients, thyroid-stimulating hormone levels were measured at the first day after infarction and 4 months thereafter. Cardiac magnetic resonance scans were performed within the first week as well as at 4 months follow-up to determine infarct characteristics, myocardial function and as primary endpoint left ventricular remodeling, defined as a 20% or greater increase in left ventricular end-diastolic volume.

RESULTS

Patients with left ventricular remodeling (n=15, 15%) showed significantly lower concentrations of baseline (1.20 [0.92-1.91] vs. 1.73 [1.30-2.60] mU/l; P=0.02) and follow-up (1.11 [0.86-1.28] vs. 1.51 [1.15-2.02] mU/l; P=0.002) thyroid-stimulating hormone. The association between baseline thyroid-stimulating hormone and left ventricular remodeling remained significant after adjustment for major clinical (peak high-sensitivity cardiac troponin T and C-reactive protein, heart rate; odds ratio (OR) 5.33, 95% confidence interval (CI) 1.52-18.63; P=0.01) and cardiac magnetic resonance predictors of left ventricular remodeling (infarct size, microvascular obstruction, ejection fraction; OR 4.59, 95% CI 1.36-15.55; P=0.01). Furthermore, chronic thyroid-stimulating hormone was related to left ventricular remodeling independently of chronic left ventricular remodeling correlates (infarct size, ejection fraction, left ventricular end-diastolic volume, left ventricular end-systolic volume; OR 9.22, 95% CI 1.69-50.22; P=0.01).

CONCLUSIONS

Baseline and chronic thyroid-stimulating hormone concentrations following STEMI were independently associated with left ventricular remodeling, proposing a novel pathophysiological axis in the development of post-STEMI left ventricular remodeling.

Relationship between diabetes and ischaemic injury among patients with revascularized ST-elevation myocardial infarction

AIMS

Studies comparing reperfusion efficacy and myocardial damage between diabetic and non-diabetic patients with ST-elevation myocardial infarction (STEMI) are scarce and have reported conflicting results. The aim was to investigate the impact of preadmission diabetic status on myocardial salvage and damage as determined by cardiac magnetic resonance (CMR), and to evaluate its prognostic relevance.

MATERIALS AND METHODS

We enrolled 792 patients with STEMI at 8 sites. CMR core laboratory analysis was performed to determine infarct characteristics. Major adverse cardiac events (MACE), defined as a composite of all-cause death, non-fatal re-infarction and new congestive heart failure, were recorded at 12 months. Patients were categorized according to preexisting diabetes mellitus (DM), and according to insulin-treated DM (ITDM) and non-insulin-treated DM (NITDM).

RESULTS

One-hundred and sixty (20%) patients had DM and 74 (9%) were insulin-treated. There was no difference in the myocardial salvage index, infarct size, microvascular obstruction and left ventricular ejection fraction between all patient groups (all P > .05). Patients with DM were at higher risk of MACE (11% vs 6%, P = .03) than non-DM patients. After stratification according to preadmission anti-diabetic therapy, MACE rate was comparable between NITDM and non-DM (P > .05), whereas the group of ITDM patients had significantly worse outcome (P < .001).

CONCLUSIONS

Diabetic patients with STEMI, especially those having ITDM, had an increased risk of MACE. The adverse clinical outcome was, however, not explained by an impact of DM on reperfusion success or myocardial damage. Clinical trial registry number: NCT00712101.

Relation of Low-Density Lipoprotein Cholesterol With Microvascular Injury and Clinical Outcome in Revascularized ST-Elevation Myocardial Infarction

BACKGROUND

Microvascular injury (MVI) after primary percutaneous coronary intervention for ST-elevation myocardial infarction (STEMI) is a major determinant of adverse clinical outcome. Experimental data indicate an impact of hypercholesterolemia on MVI; however, there is a lack of clinical studies confirming this relation. We aimed to investigate the association of cholesterol concentrations on admission with MVI visualized by cardiac magnetic resonance imaging and clinical outcome in STEMI patients treated by primary percutaneous coronary intervention.

METHODS AND RESULTS

In this prospective, observational study, we included 235 consecutive revascularized STEMI patients. Cholesterol (total cholesterol, low-density lipoprotein [LDL], and high-density lipoprotein cholesterol) and triglyceride concentrations were determined at presentation. Cardiac magnetic resonance scans were performed 2 (2-4) days after infarction to assess infarct characteristics, including MVI. Clinical end point was the occurrence of major adverse cardiac events (MACE) comprising all-cause mortality, nonfatal reinfarction, and new congestive heart failure. Patients with MVI (n=129; 55%) showed higher levels of total cholesterol (204 [172-226] versus 185 [168-212] mg/dL; P=0.01) and LDL cholesterol (142 [113-166] versus 118 [103-149] mg/dL; P=0.001), whereas high-density lipoprotein cholesterol and triglycerides did not differ significantly. In multivariable analysis, including all significant clinical and cardiac magnetic resonance determinants of MVI, LDL concentration emerged as an independent predictor of MVI (odds ratio, 1.02 [95% confidence interval, 1.01-1.02]; P=0.002). Furthermore, increased LDL cholesterol (>150 mg/dL) significantly predicted the occurrence of major adverse cardiac events (hazard ratio, 3.09 [95% confidence interval, 1.22-7.87]; P=0.01).

CONCLUSIONS

In STEMI patients undergoing primary percutaneous coronary intervention, baseline LDL cholesterol concentrations were independently associated with MVI, revealing a clinically relevant link between LDL metabolism and MVI in acute STEMI.

Prognostic Value of Aortic Stiffness in Patients After ST-Elevation Myocardial Infarction

BACKGROUND

High aortic stiffness has been shown to be a strong predictor of morbidity and mortality in the general population and several patient cohorts. However, in patients after ST-elevation myocardial infarction, the prognostic value of high aortic stiffness is unknown so far.

METHODS AND RESULTS

This prospective observational study included 160 consecutive patients with first acute ST-elevation myocardial infarction. Aortic pulse wave velocity (PWV) was measured 2 (interquartile range 2-4 days) days after infarction using cardiac magnetic resonance imaging. The primary end point was defined as a composite end point of major adverse cardiac and cerebrovascular events (MACCE) comprising death, nonfatal myocardial reinfarction, new congestive heart failure, and stroke. During a median follow-up of 1.2 years (interquartile range 1.0-3.1 years), 19 (12%) MACCE events occurred. Kaplan-Meier analysis showed a significantly lower MACCE-free survival in patients with high PWV (PWV >7.3 m/s, log-rank P=0.003). Multivariable Cox regression analysis revealed PWV >7.3 m/s to be an independent predictor of MACCE after adjustment for age, sex, mean blood pressure, N-terminal pro-brain natriuretic peptide levels, presence of multivessel disease, and left ventricular stroke volume (hazard ratios ≥3.5; 95% confidence interval 1.4-13.3; all P≤0.018). In reclassification analysis the addition of PWV to a risk model comprising major clinical prognostic parameters led to a net reclassification improvement of 0.11 (95% confidence interval 0.06-0.17; P<0.001).

CONCLUSIONS

Increased aortic stiffness is an independent predictor of MACCE after acute ST-elevation myocardial infarction. Moreover, the assessment of aortic stiffness in addition to classical risk factors significantly improved early risk stratification.

Multimarker approach for the prediction of microvascular obstruction after acute ST-segment elevation myocardial infarction: a prospective, observational study

Background

Presence of microvascular obstruction (MVO) derived from cardiac magnetic resonance (CMR) imaging is among the strongest outcome predictors after ST-segment elevation myocardial infarction (STEMI). We aimed to investigate the comparative predictive values of different biomarkers for the occurrence of MVO in a large cohort of reperfused STEMI patients.

Methods

This study included 128 STEMI patients. CMR imaging was performed within the first week after infarction to assess infarct characteristics, including MVO. Admission and peak concentrations of high-sensitivity cardiac troponin T (hs-cTnT), creatine kinase (CK), N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (hs-CRP), lactate dehydrogenase (LDH), aspartate transaminase (AST) and alanine transaminase (ALT) were measured.

Results

MVO was detected in 69 patients (54%). hs-cTnT, CK, hs-CRP, LDH, AST and ALT peak concentrations showed similar prognostic value for the prediction of MVO (area under the curve (AUC) = 0.77, 0.77, 0.68, 0.79, 0.78 and 0.73, all p > 0.05), whereas the prognostic utility of NT-proBNP was weakly lower (AUC = 0.64, p < 0.05). Combination of these biomarkers did not increase predictive utility compared to hs-cTnT alone (p = 0.349).

Conclusions

hs-cTnT, CK, hs-CRP, LDH, AST and ALT peak concentrations provided similar prognostic value for the prediction of MVO. The prognostic utility of NT-proBNP was lower. Combining these biomarkers could not further improve predictive utility compared to hs-cTnT alone.

Antecedent hypertension and myocardial injury in patients with reperfused ST-elevation myocardial infarction

BACKGROUND

Antecedent hypertension is associated with poor outcome in patients with ST-elevation myocardial infarction (STEMI). Whether differences in myocardial salvage, infarct size and microvascular injury contribute to the adverse outcome is unknown. We investigated the association between antecedent hypertension and cardiovascular magnetic resonance (CMR) parameters of myocardial salvage and damage in a multicenter CMR substudy of the AIDA-STEMI trial (Abciximab Intracoronary versus intravenously Drug Application in ST-elevation myocardial infarction).

METHODS

We analyzed 792 consecutive STEMI patients reperfused within 12 h after symptom onset. Patients underwent CMR imaging for assessment of myocardial salvage, infarct size and microvascular obstruction within 10 days after infarction. Major adverse cardiac events (MACE) were recorded at 12-month follow-up.

RESULTS

Antecedent hypertension was present in 540 patients (68 %) and was associated with a significantly increased baseline risk profile (advanced age, higher body mass index, higher incidence of diabetes, hypercholesterolemia, previous angioplasty and multivessel disease, p < 0.001 for all). MACE were more frequent in patients with hypertension as compared to patients without hypertension (45 [8 %] vs. 8 [3 %], p < 0.01). Antecedent hypertension remained an independent predictor of MACE after multivariate adjustment (hazard ratio 3.42 [confidence interval 1.45-8.08], p < 0.01). There was, however, no significant difference in the area at risk, infarct size, myocardial salvage index, extent of microvascular obstruction, and left ventricular ejection fraction between the groups (all p > 0.05).

CONCLUSION

Despite a higher rate of MACE in contemporary reperfused STEMI patients with antecedent hypertension, there was no difference in reperfusion efficacy, infarct size and reperfusion injury as visualized by CMR.

TRIAL REGISTRATION

NCT00712101 .

Combined biomarker testing for the prediction of left ventricular remodelling in ST-elevation myocardial infarction

Objective

The utility of different biomarkers for the prediction of left ventricular remodelling (LVR) following ST-elevation myocardial infarction (STEMI) has been evaluated in several studies. However, very few data exist on the prognostic value of combined biomarkers. The aim of this study was to comprehensively investigate the prognostic value for LVR of routinely available biomarkers measured after reperfused STEMI.

Methods

Serial measurements of N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity cardiac troponin T (hs-cTnT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and high-sensitivity C reactive protein (hs-CRP) were performed in 123 patients with STEMI treated with primary percutaneous coronary intervention in this prospective observational study. Patients underwent cardiac MRI at 2 (1–4) and 125 (121–146) days after infarction. An increase in end-diastolic volume of ≥20% was defined as LVR.

Results

LVR occurred in 16 (13%) patients. Peak concentrations of the following biomarkers showed significant areas under the curves (AUCs) for the prediction of LVR—NT-proBNP: 0.68 (95% CI 0.59 to 0.76, p=0.03), hs-cTnT: 0.75 (95% CI 0.66 to 0.82, p<0.01), AST: 0.72 (95% CI 0.63 to 0.79, p<0.01), ALT: 0.66 (95% CI 0.57 to 0.75, p=0.03), LDH: 0.78 (95% CI 0.70 to 0.85, p<0.01) and hs-CRP: 0.63 (95% CI 0.54 to 0.72, p=0.05). The combination of all biomarkers yielded a significant increase in AUC to 0.85 (95% CI 0.77 to 0.91) (all vs NT-proBNP: p=0.02, all vs hs-cTnT: p=0.02, all vs AST: p<0.01, all vs ALT: p<0.01, all vs hs-CRP: p<0.01 and all vs LDH: p=0.04).

Conclusions

In patients with reperfused STEMI, the combined assessment of peak NT-proBNP, hs-cTnT, AST, ALT, hs-CRP and LDH provide incremental prognostic information for the prediction of LVR when compared with single-biomarker measurement.

Relation of inflammatory markers with myocardial and microvascular injury in patients with reperfused ST-elevation myocardial infarction

BACKGROUND

In patients with acute ST-elevation myocardial infarction (STEMI), elevated concentrations of inflammatory markers are correlated with worse clinical outcome. The aim of this study was comprehensively to investigate the relationship of circulating markers of inflammation with myocardial and microvascular damage after STEMI.

METHODS

In 111 consecutive STEMI patients, blood samples were obtained on admission and from day 1 to day 4 after primary percutaneous coronary intervention and analysed for high-sensitivity C-reactive protein (hs-CRP), white blood cell count and fibrinogen. Cardiac magnetic resonance imaging was performed within the first week and 4 months after primary percutaneous coronary intervention.

RESULTS

Peak concentrations of hs-CRP (20.5 (9.6-44.4) mg/L), white blood cell count (12.4 (10.5-15.3) G/L) and fibrinogen (3640 (3150-4550) mg/L) showed significant correlations with both infarct size ( r=0.31 to 0.41; P<0.01) and left ventricular ejection fraction ( r=-0.29 to -0.39; P<0.01) assessed in the acute as well as chronic stage following STEMI. Furthermore, peak concentrations of these inflammatory markers were significantly higher in patients with microvascular obstruction compared to patients without microvascular obstruction ( P⩽0.01). C-statistics revealed that the prognostic values of all three biomarkers for the prediction of large chronic infarct size (>8% of left ventricular myocardial mass) were moderate without significant differences (area under the curve: hs-CRP 0.73 (95% confidence interval (CI) 0.63-0.82), white blood cell count 0.67 (95% CI 0.56-0.78) and fibrinogen 0.69 (95% CI 0.59-0.79); all P>0.12). Combination of inflammatory markers did not significantly increase the area under the curve ( P>0.05).

CONCLUSION

In reperfused STEMI patients, increased levels of hs-CRP, white blood cell count and fibrinogen are associated with decreased left ventricular function and more pronounced myocardial damage at baseline and 4 months after infarction.

Heart rate and left ventricular adverse remodelling after ST-elevation myocardial infarction

BACKGROUND

Discharge heart rate (HR) following ST-elevation myocardial infarction (STEMI) is a predictor of adverse left ventricular remodelling (LVR). However, the prognostic relevance of HR values in the earlier phase after revascularization is unknown. We aimed to investigate resting HR assessed at different time points during hospital stay following STEMI for the prediction of LVR.

METHODS

In this prospective observational study of 143 consecutive STEMI patients, HR was measured serially on admission (AHR), at day 1 (HRd1) and 2 (HRd2) following revascularization and finally at discharge (DHR). Cardiac magnetic resonance (CMR) scans were performed at baseline and 4months thereafter to evaluate LVR and major CMR determinants of LVR (infarct size, microvascular obstruction). LVR was defined as ≥15% increase of left ventricular end-diastolic volume.

RESULTS

Twenty-nine patients (20%) have developed LVR. HRd1 (80[72-88] vs. 71[62-79]bpm, p=0.003), HRd2 (74[64-83] vs. 67[59-78]bpm, p=0.04), DHR (74[62-81] vs. 64[58-73] bpm, p=0.008) and the mean HR of all measurements (76[68-82] vs. 67[60-77]bpm, p=0.004) were significantly higher in patients with LVR, whereas admission HR (75[68-85] vs. 70[60-82]bpm, p=0.12) did not differ significantly. The associations for all post-admission HRs remained significant after adjustment for clinical (high-sensitivity cardiac troponin T and C-reactive protein, left anterior descending artery as culprit) and CMR (infarct size, microvascular obstruction, ejection fraction) predictors of LVR. The predictive values of the post-admission HRs were equivalent (area under the curve differences: all p>0.05).

CONCLUSION

Besides DHR, resting HR values in the early stage following reperfusion are independent predictors of LVR after STEMI.

Comparison of Characteristics of Patients aged ≤45 Years Versus >45 Years With ST-Elevation Myocardial Infarction (from the AIDA STEMI CMR Substudy)

It is unknown whether the occurrence of ST-elevation myocardial infarction (STEMI) at a younger age is associated with differences in myocardial damage compared with older patients. We aimed to compare the infarct characteristics (area at risk [AAR], myocardial salvage index [MSI], infarct size [IS], microvascular obstruction [MVO]) and clinical outcome in patients aged ≤45 years and >45 years. We analyzed 795 patients with STEMI treated with primary percutaneous coronary intervention. All patients completed 12-month follow-up for the assessment of major adverse cardiac events (MACE). Left ventricular ejection fraction, AAR, MSI, IS, and MVO were determined by cardiac magnetic resonance imaging. Seventy-eight patients (9.8%) were aged 45 years or younger. Young patients were more likely to be male (p = 0.01), to be current smokers (p <0.001), and to have a family history of coronary artery disease (p = 0.05). Contrary, they had significantly lower prevalence of hypertension (p <0.001), diabetes (p <0.01), and 3-vessel disease (p <0.01). There were no significant differences in left ventricular ejection fraction (p = 0.36), AAR (p = 0.30), MSI (p = 0.34), IS (p = 0.29), or MVO (p = 0.58) between both groups. MACE rate was significantly lower in patients aged ≤45 years compared with patients aged >45 years (1.3% vs 7.5%, p = 0.04). After multivariate adjustment for clinical risk factors and cardiac magnetic resonance findings, age remained an independent predictor of MACE (hazard ratio 1.04, 95% CI 1.01 to 1.07, p = 0.03). In conclusion, infarct characteristics are not dependent on age in patients undergoing primary percutaneous coronary intervention for STEMI.

Aortic stiffness is associated with elevated high-sensitivity cardiac troponin T concentrations at a chronic stage after ST-segment elevation myocardial infarction

OBJECTIVES

Aortic pulse wave velocity (PWV)--the proposed gold standard for the assessment of aortic stiffness--is a major determinant of left ventricular after-load and coronary perfusion. We aimed to investigate the association between aortic PWV and subclinical elevation of high-sensitivity cardiac troponin T (hs-TnT) concentrations at a chronic stage after acute ST-segment elevation myocardial infarction (STEMI).

METHODS

Seventy-four patients with acute STEMI were included in this cross-sectional single-centre study at the University Hospital of Innsbruck. All patients underwent cardiac MRI for the assessment of left ventricular function, morphology, infarct size and aortic PWV 12 months after acute STEMI. Blood samples were drawn at 12 months by peripheral venipuncture. Levels of hs-TnT were measured by a commercially available immunoassay (Roche Diagnostics).

RESULTS

hs-TnT levels (6.4 ng/l, inter-quartile range 5.0-8.6) were significantly associated with age (r = 0.417, P < 0.001), plasma creatinine levels (r = 0.257, P = 0.027), high-sensitivity C-reactive protein levels (r = 0.281, P = 0.015) and aortic PWV (r = 0.435, P < 0.001). Multiple linear regression analysis revealed aortic PWV (ß = 0.330, P = 0.025), apart from plasma creatinine concentrations (ß = 0.279, P = 0.010), to be independently associated with hs-TnT concentrations (model: R = 0.597, P < 0.001).

CONCLUSION

The present study showed an association of aortic stiffness and hs-TnT concentrations at a chronic stage after STEMI.

Association of smoking with myocardial injury and clinical outcome in patients undergoing mechanical reperfusion for ST-elevation myocardial infarction

AIMS

There is evidence suggesting a positive effect of cigarette smoking on myocardial tissue reperfusion and clinical outcomes in patients with myocardial infarction ('smoker's paradox'). We aimed to evaluate the relationship of smoking with cardiac magnetic resonance (CMR)-determined myocardial salvage and damage as well as clinical outcomes in patients undergoing primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This multicentre study included 727 consecutive STEMI patients reperfused within 12 h after symptom onset. CMR imaging parameters [area at risk (AAR), infarct size (IS), myocardial salvage index (MSI), and microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH)] were compared according to admission smoking status. Major adverse cardiac event (MACE) rates at 12 months after infarction were compared between groups. Three hundred and thirty-nine (46.6%) patients were current smokers. There was no difference in the extent of AAR [35 (24-47) vs. 37 (27-49) % of left ventricular volume (LV), P = 0.10], IS [16 (8-25) vs. 17 (10-26) %LV, P = 0.21], MSI [53 (29-70) vs. 52 (34-71), P = 0.47], MVO [0 (0-1.7) vs. 0 (0-1.6) %LV, P = 0.91], or in the frequency of IMH (42 vs. 39%, P = 0.58) between smokers and non-smokers. Smokers had lower MACE (3.8 vs. 8.2%, P = 0.01) rates. However, adjustment for differences in baseline risk factors attenuated the association of smoking with MACE markedly (hazard ratio = 0.71, 95% confidence interval 0.36-1.38, P = 0.31).

CONCLUSION

Smoking is not associated with PPCI efficacy (myocardial salvage) or irreversible myocardial damage in patients with STEMI. The lower MACE rate of smokers was entirely explained by differences in baseline risk characteristics, thus challenging the existence of a smoker's paradox.

Association of serum cystatin C levels with myocardial perfusion and cardiac functional recovery in patients with anterior wall ST elevation myocardial infarction treated with primary coronary intervention

This study sought to investigate the association of baseline serum cystatin C levels with myocardial perfusion and cardiac functional recovery in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). 108 patients with a first anterior STEMI who underwent PPCI were enrolled. Serum cystatin C was measured by immunoturbidimetric method. Patients were divided into two groups according to the median cystatin C levels on admission: group 1 (≥median, n = 54) and group 2 (<median, n = 54). Myocardial perfusion was assessed by angiographic criteria, ST-segment resolution, and the index of microcirculatory resistance (IMR). Echocardiographic wall motion score index was analyzed on admission and at 6-month follow-up. Patients with angiographically, electrocardiographically no-reflow had significantly higher cystatin C levels on admission. Patients with an IMR ≥33.7 U also had significantly higher cystatin C levels. The WMSI showed a greater improvement in group 2 than in group 1 and there was a significant negative correlation between improvement of WMSI and the cystatin C levels. There was no significant difference in MACEs between the 2 groups. However, congestive heart failure (CHF) was observed significantly more frequent in group 1 than in group 2 (18.5 vs. 5.6 %, p = 0.022). Multivariate logistic regression analysis demonstrated that cystatin C levels at admission were a significant independent predictor of angiographic no-reflow and the development of CHF at 6-month follow-up. Elevated cystatin C levels at admission were independently associated with impaired myocardial perfusion, poor cardiac functional recovery and development of CHF in patients with anterior STEMI undergoing PPCI.

N-terminal pro-B-type natriuretic peptide is associated with aortic stiffness in patients presenting with acute myocardial infarction

BACKGROUND

Aortic stiffness is associated with increased left ventricular (LV) afterload, a process which is accompanied by a release of natriuretic peptides. Aortic pulse wave velocity (PWV) has been demonstrated to be the functional surrogate of aortic stiffness. We sought to investigate the impact of aortic PWV on N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations in patients with acute myocardial infarction (AMI).

METHODS

This prospective observational study included 86 consecutive patients undergoing percutaneous coronary intervention for AMI. Aortic PWV was determined 47 h (interquartile range (IQR) 27-64 h) after AMI using an established oscillometric device. NT-proBNP values were measured using a commercially available immunoassay.

RESULTS

The mean age of the study cohort was 60±11 years; 19% were female. Median aortic PWV was 7.8 m/s (IQR 6.8-9.4 m/s). Patients with a PWV above the median showed significantly higher NT-proBNP peak concentrations (median=1330 ng/l, IQR: 729-3180 ng/l vs median=498 ng/l, IQR: 124-1575 ng/l, p=0.001). Aortic PWV (beta=0.373, p=0.014) was independently associated with NT-proBNP peak concentrations even after correction for LV function, cardiac troponin T levels, heart rate, blood pressure, body mass index and the primary prevention European Society of Cardiology (ESC) SCORE (model: R=0.542, p=0.014).

CONCLUSION

In patients with AMI, aortic PWV is independently associated with NT-proBNP concentrations. This finding suggests an impact of aortic PWV on myocardial wall stress after AMI.

Prognostic significance of transaminases after acute ST-elevation myocardial infarction: insights from a cardiac magnetic resonance study

BACKGROUND

In patients with ST-elevation myocardial infarction (STEMI), the relationship between transaminases and myocardial damage detected by cardiac magnetic resonance (CMR) imaging is unknown and the prognostic value incompletely investigated.

MATERIALS AND METHODS

CMR imaging was performed in 167 STEMI patients 2.3 [1.6-3.9] days after primary percutaneous coronary intervention (PPCI). Blood samples for transaminase measurement (aspartate transaminase (AST) and alanine transaminase (ALT)) were obtained serially from day 1 to day 4 after PPCI. Patients were followed for major adverse cardiac events (MACE) for 2.7 [1.1-3.3] years.

RESULTS

Admission and peak concentrations of AST and ALT were significantly associated with ejection fraction (p < 0.001), infarct size (p < 0.001), and the presence of microvascular obstruction (p < 0.01). Peak values of both transaminases showed a stronger correlation with CMR parameters than admission values (all p < 0.05). In Kaplan-Meier analysis, a high peak AST or high peak ALT was associated with reduced MACE-free survival (both p < 0.01), whereas admission values were not (both p > 0.05). Peak AST (hazard ratio (HR): 4.93 [1.70-14.32], p = 0.003) and peak ALT (HR: 5.67 [1.94-16.56], p = 0.002) were independent predictors of MACE after adjusting for clinical risk factors.

CONCLUSIONS

Transaminases measured in the acute phase after PPCI for STEMI are associated with systolic dysfunction, more extensive myocardial necrosis and microvascular injury with subsequent prognostic information on MACE at long-term follow-up.

Cardiac index after acute ST-segment elevation myocardial infarction measured with phase-contrast cardiac magnetic resonance imaging

OBJECTIVES

Phase-contrast CMR (PC-CMR) might provide a fast and robust non-invasive determination of left ventricular function in patients after ST-segment elevation myocardial infarction (STEMI).

METHODS

Cine sequences in the left-ventricular (LV) short-axis and free-breathing, retrospectively gated PC-CMR were performed in 90 patients with first acute STEMI and 15 healthy volunteers. Inter- and intra-observer agreement was determined. The correlations of clinical variables (age, gender, ejection fraction, NT pro-brain natriuretic peptide [NT-proBNP] with cardiac index (CI) were calculated.

RESULTS

For CI, there was a strong agreement of cine CMR with PC-CMR in healthy volunteers (r: 0.82, mean difference: -0.14 l/min/m(2), error ± 23 %). Agreement was lower in STEMI patients (r: 0.61, mean difference: -0.17 l/min/m(2), error ± 32 %). In STEMI patients, CI measured with PC-CMR showed lower intra-observer (1 % vs. 9 %) and similar inter-observer variability (9 % vs. 12 %) compared to cine CMR. CI was significantly correlated with age, ejection fraction and NT-proBNP values in STEMI patients.

DISCUSSION

The agreement of PC-CMR and cine CMR for the determination of CI is lower in STEMI patients than in healthy volunteers. After acute STEMI, CI measured with PC-CMR decreases with age, LV ejection fraction and higher NT-proBNP.

KEY POINTS

• Cine CMR and PC-CMR correlate well in healthy volunteers. • Agreement is lower in STEMI patients. • Cardiac Output should be measured with one method longitudinally. • Cardiac output decreases with age after myocardial infarction.

High-sensitivity troponin T for prediction of left ventricular function and infarct size one year following ST-elevation myocardial infarction

BACKGROUND

Data relating high-sensitivity cardiac troponin T (hs-cTnT) to long-term myocardial function and infarct size in patients after ST-elevation myocardial infarction (STEMI) are lacking. We aimed to evaluate the use of early hs-cTnT concentrations for prediction of myocardial function and infarct size assessed by cardiac magnetic resonance imaging (CMR) one year following STEMI.

METHODS

Sixty-six patients, revascularized by primary percutaneous coronary intervention (PCI) for first-time STEMI, were enrolled in this observational study. Serial hs-cTnT, creatine kinase (CK), high-sensitivity C-reactive protein (hs-CRP) and lactate dehydrogenase (LDH) levels were measured on admission, 6 h, 12 h, and 24 h post-PCI. Patients underwent CMR within the first week and 12months thereafter.

RESULTS

Except for admission hs-cTnT, all single time point and peak hs-cTnT concentrations showed significant correlations with left ventricular ejection fraction (LVEF: r=-0.404 to -0.517, all ps<0.01) and infarct size (IS: r=0.421 to 0.700, all ps<0.01) at baseline and follow-up. The area under the curve (AUC) of peak hs-cTnT was 0.82 (95% CI 0.71-0.92) for the prediction of decreased LVEF (<55%) and 0.89 (95% CI 0.81-0.97) for the prediction of large IS (>8%) at 12months. The combination of all four biomarkers resulted in an AUC of 0.82 and 0.92 for the prediction of reduced LVEF and large IS at 12months, respectively (both ps>0.05).

CONCLUSION

In stable STEMI patients successfully revascularized by primary PCI, serial and peak concentrations of hs-cTnT are closely correlated to long-term LVEF and IS. Combination of hs-cTnT with CK, hs-CRP, or LDH did not add any significant prognostic value as compared with hs-cTnT alone.

Fetuin-A is related to infarct size, left ventricular function and remodelling after acute STEMI

Objective

To investigate the relationship between plasma fetuin-A, an anti-inflammatory glycoprotein which might be involved in myocardial healing after acute infarction, and infarct size, left ventricular (LV) function and dimensions as well as the occurrence of adverse remodelling at 4 months after acute ST segment elevation myocardial infarction (STEMI).

Methods

In this single-centre prospective, observational study, 89 patients underwent cardiac MR within the first week and 4 months after mechanical reperfusion for first STEMI. Infarct size, LV function and dimensions were assessed at both time points. Fetuin-A levels were determined from blood samples drawn at a median of 49 h (IQR 30–59 h) after STEMI by an immunofluorescent assay.

Results

Fetuin-A levels (median 568 µg/mL, IQR 478–763 µg/mL) were significantly correlated with infarct size and LV ejection fraction at baseline and follow-up (all p<0.05). Moreover, fetuin-A was related to the increase in the end-diastolic volume index (r=−0.383, p<0.001). According to multivariate logistic regression analysis, fetuin-A concentrations (HR=0.17, 95% CI 0.03 to 0.89, p=0.036) besides the presence of late microvascular obstruction (HR=10.03, 95% CI 0.98 to 102.43, p=0.05) were significantly related to the occurrence of adverse LV remodelling at 4 months.

Conclusions

Circulating fetuin-A at day 2 after STEMI is related to acute and chronic infarct size, LV function and dimensions. In addition, it might be useful to identify patients at increased risk for adverse LV remodelling.

Prognostic value of left ventricular global function index in patients after ST-segment elevation myocardial infarction

AIMS

The left ventricular global function index (LVGFI) is a novel indicator of left ventricular performance. Its prognostic value in patients after ST-segment elevation myocardial infarction (STEMI) is unknown. We sought to evaluate the prognostic significance of LVGFI measured by cardiovascular magnetic resonance (CMR) imaging after STEMI.

METHODS AND RESULTS

Two hundred eligible STEMI patients (56 ± 11 years, 16% female) revascularized by primary percutaneous coronary intervention were followed-up for 3.1 [2-4.1] years for major adverse cardiac events (MACE). MACE was defined as a composite of death, non-fatal myocardial re-infarction, and new congestive heart failure. All patients underwent CMR imaging within 2 [2-4] days after STEMI. Late enhancement and cine images were acquired to assess myocardial injury as well as myocardial function, including LVGFI. Patients suffering a MACE event (n = 20, 10%) had a significantly lower LVGFI (P = 0.001). In Kaplan-Meier analysis, a decreased LVGFI was associated with a reduced MACE-free survival (P < 0.001). Multivariate Cox regression analysis revealed a decreased LVGFI as a predictor for MACE [hazard ratio = 4.79, 95% confidence interval (CI) 1.46-15.67, P = 0.010] after adjusting for microvascular obstruction, left ventricular mass, and multivessel disease. In receiver operating characteristic analysis, LVGFI was a strong predictor for MACE (area under the curve = 0.73, CI 0.61-0.85). However, c-statistics revealed that LVGFI does not provide incremental prognostic information over left ventricular ejection fraction (LVEF) (P = 0.38).

CONCLUSION

LVGFI assessed by CMR is a strong predictor of MACE within 3 years after first STEMI. A superior predictive value as compared with LVEF was not found in this study.

Comparison of an oscillometric method with cardiac magnetic resonance for the analysis of aortic pulse wave velocity

Objectives

Pulse wave velocity (PWV) is the proposed gold-standard for the assessment of aortic elastic properties. The aim of this study was to compare aortic PWV determined by a recently developed oscillometric device with cardiac magnetic resonance imaging (CMR).

Methods

PWV was assessed in 40 volunteers with two different methods. The oscillometric method (PWV_OSC) is based on a transfer function from the brachial pressure waves determined by oscillometric blood pressure measurements with a common cuff (Mobil-O-Graph, I.E.M. Stolberg, Germany). CMR was used to determine aortic PWV_CMR with the use of the transit time method based on phase-contrast imaging at the level of the ascending and abdominal aorta on a clinical 1.5 Tesla scanner (Siemens, Erlangen, Germany).

Results

The median age of the study population was 34 years (IQR: 24–55 years, 11 females). A very strong correlation was found between PWVOSC and PWVCMR (r = 0.859, p < 0.001). Mean PWV_OSC was 6.7 ± 1.8 m/s and mean PWVCMR was 6.1 ± 1.8 m/s (p < 0.001). Analysis of agreement between the two measurements using Bland-Altman method showed a bias of 0.57 m/s (upper and lower limit of agreement: 2.49 m/s and -1.34 m/s). The corresponding coefficient of variation between both measurements was 15%.

Conclusion

Aortic pulse wave velocity assessed by transformation of the brachial pressure waveform showed an acceptable agreement with the CMR-derived transit time method.

Use and limitations of cardiac magnetic resonance derived measures of aortic stiffness in patients after acute myocardial infarction

INTRODUCTION

Cardiac magnetic resonance (CMR) is a unique method to determine regional and local aortic stiffness parameters. Although various methods have been validated, there are no data in patients after acute ST-segment elevation myocardial infarction (STEMI). In the present study we assessed the feasibility of different CMR derived measures of aortic stiffness in patients after first acute STEMI for the first time.

METHODS

CMR derived aortic pulse wave velocity (PWV) determined by the regional transit-time (PWVTT) and local flow-area (PWVQA) method as well as local distensibility coefficients (DCs) was analyzed in 22 healthy young volunteers and 28 patients with recent acute STEMI.

RESULTS

PWVTT and DC of the ascending aorta differed significantly between healthy subjects and STEMI patients (all p<0.001). PWVQA at thoracic levels of aorta was not different between groups (p>0.520) and did not correlate with age (p>0.149) and PWVTT (p>0.310). Intra- and interobserver variability was high for PWVTT (r=0.970, p<0.001 and r=0.920, p<0.001), acceptable for DC (all r>0. 809, p<0.001 and all r>0.510, p<0.001) but low for thoracic PWVQA (all r<0.330 and all r<0.372).

CONCLUSION

PWVTT and local DC are robust methods for the assessment of aortic stiffness in patients after acute STEMI.

Relation of plasma adiponectin levels and aortic stiffness after acute ST-segment elevation myocardial infarction

BACKGROUND

Pulse wave velocity is a measure of aortic stiffness and an independent predictor of cardiovascular morbidity and mortality. Adiponectin is involved in atherosclerosis and inflammation. In the present study we aimed to explore the association between plasma adiponectin concentrations and pulse wave velocity in the acute phase after ST-segment elevation myocardial infarction (STEMI).

METHODS

Forty-six consecutive STEMI patients (mean age 57 ± 11 years) treated with primary percutaneous coronary intervention (PCI) were enrolled in this cross-sectional study. Plasma adiponectin was measured 2 days after index event by enzyme-linked immunosorbent assay. Aortic pulse wave velocity (PWV) was calculated by the transit-time method with the use of a velocity-encoded, phase-contrast cardiac magnetic resonance protocol.

RESULTS

Median plasma adiponectin concentration was 2385 ng/ml (interquartile range 1735-5403). Males had lower plasma adiponectin values than females and current smokers had lower values than non-smokers (all p<0.02). Adiponectin was significantly associated with PWV (r=0.505, p<0.001), age (r=0.437, p=0.002), and total cholesterol (r=0.468, p=0.001). Multiple linear regression analysis revealed adiponectin as a predictor of PWV independently of age, sex, smoking status, total cholesterol, and N-terminal pro-B-type natriuretic peptide (p=0.027).

CONCLUSIONS

Plasma adiponectin concentrations are strongly associated with aortic stiffness in patients after acute STEMI treated with primary PCI. Our data support a possible role for adiponectin as an independent risk marker for increased aortic stiffness in STEMI patients.

Association of copeptin with myocardial infarct size and myocardial function after ST segment elevation myocardial infarction

OBJECTIVE

To investigate the relationship between circulating plasma copeptin values and infarct size as well as myocardial function at baseline and 4 months after mechanical reperfusion for ST segment elevation myocardial infarction (STEMI).

DESIGN

Prospective observational cohort study.

SETTING

University Hospital of Innsbruck.

PATIENTS

54 patients with acute STEMI.

MAIN OUTCOME MEASURES

Correlation of plasma copeptin with infarct size as well as left ventricular ejection fraction (LVEF) and remodelling.

METHODS

Participants underwent contrast enhanced cardiac MRI at baseline and 4 months thereafter. Blood samples were drawn 2 days after the onset of symptoms. Copeptin values were determined by an immunofluorescent assay.

RESULTS

Copeptin concentrations (median 10.4 pmol/l, IQR 6.0-14.4) were associated with early and chronic infarct size (r=0.388, p=0.004 at baseline; r=0.385, p=0.011 at follow-up) and inversely related to LVEF at both times (r=-0.484, p<0.001 at baseline; r=-0.461, p<0.001 at follow-up). Patients with adverse remodelling showed higher baseline copeptin values compared to patients without remodelling (p=0.02). Receiver operating characteristic analysis indicated a cut-off value of 16.7 pmol/l for copeptin to best identify patients with future adverse remodelling.

CONCLUSIONS

Increased copeptin values 2 days after STEMI are associated with larger acute and chronic infarct sizes. Moreover, elevated copeptin concentrations at baseline were associated with myocardial function and remodelling 4 months post-STEMI. These findings strengthen the role of copeptin as a biomarker of adverse outcome after STEMI.