Prognostic significance and relationship of worst lead residual ST segment elevation with myocardial damage assessed by cardiovascular MRI in myocardial infarction

Residual ST-segment elevation to predict long-term clinical and CMR-derived outcomes in STEMI

Residual ST-segment elevation after ST-segment elevation myocardial infarction (STEMI) has traditionally been considered a predictor of left ventricular (LV) dysfunction and ventricular aneurism. However, the implications in terms of long-term prognosis and cardiac magnetic resonance (CMR)-derived structural consequences are unclear. A total of 488 reperfused STEMI patients were prospectively included. The number of Q wave leads with residual ST-segment elevation > 1 mm (Q-STE) at pre-discharge ECG was assessed. LV ejection fraction (LVEF, %) and infarct size (IS, % of LV mass) were quantified in 319 patients at 6-month CMR. Major adverse cardiac events (MACE) were defined as all-cause death and/or re-admission for acute heart failure (HF), whichever occurred first. During a mean follow-up of 6.1 years, 92 MACE (18.9%), 39 deaths and 53 HF were recorded. After adjustment for baseline characteristics, Q-STE (per lead with > 1 mm) was independently associated with a higher risk of long-term MACE (HR 1.24 [1.07-1.44] per lead, p = 0.004), reduced (< 40%) LVEF (HR 1.36 [1.02-1.82] per lead, p = 0.04) and large (> 30% of LV mass) IS (HR 1.43 [1.11-1.85] per lead, p = 0.006) at 6-month CMR. Patients with Q-STE ≥ 2 leads (n = 172, 35.2%) displayed lower MACE-free survival, more depressed LVEF, and larger IS at 6-month CMR (p < 0.001 for all comparisons). Residual ST-segment elevation after STEMI represents a universally available tool that predicts worse long-term clinical and CMR-derived structural outcomes.

Worst lead ST deviation and resolution of ST elevation at one hour for prediction of myocardial salvage, infarct size, and microvascular obstruction in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention

Background

ECG changes after revascularization predicts improved outcome for patients with ST‐elevation myocardial infarction (STEMI). Worst lead residual (WLR) ST deviation and resolution of worst lead ST elevation (rST elevation) are simple measures that can be obtained early after PCI. The objective of the current study was to investigate whether simple ECG measures, obtained one hour following PCI, could predict cardiac magnetic resonance (CMR)‐derived myocardial salvage index (MSI), infarct size (IS), and microvascular obstruction (MVO) in patients with STEMI included in the MITOCARE trial.

Methods

The MITOCARE trial included 165 patients with a first‐time STEMI presenting within six hours of symptom onset. The current analysis included patients that had an ECG recorded at baseline and one hour after PCI and underwent CMR imaging after 3–5 days. Independent core laboratories determined WLR ST deviation, rST elevation, and the CMR variables (MSI, IS, and MVO).

Results

83 patients with a mean age of 61 years were included. 83.1% were males and 41% had anterior infarctions. In logistic regression models, WLR ST deviation was a statistically significant predictor of IS (OR 2.2, 95% CI 1.3–3.8) and MVO (OR 2.8, 95% CI 1.5–5.2), but not of MSI (OR 0.8, 95% CI 0.5–1.2). rST elevation showed a trend toward a significant association with IS (OR 0.3, 95% CI 0.1–1.0), but not with the other CMR variables.

Conclusion

WLR ST deviation one hour after PCI was a predictor of IS and MVO. WLR ST deviation, a measure easily obtained from ECGs following PCI, may provide important prognostic information in patients with STEMI.

Diagnostic and Prognostic Value of CMR T1-Mapping in Patients With Heart Failure and Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) presents a major challenge in modern cardiology. Although this syndrome is of increasing prevalence and is associated with unfavorable outcomes, treatment trials have failed to establish effective therapies. Currently, solutions to this dilemma are being investigated, including categorizing and characterizing patients more diversely to individualize treatment. In this regard, new imaging techniques might provide important information. Diastolic dysfunction is a diagnostic and pathophysiological cornerstone in HFpEF and is believed to be caused by systemic inflammation with the development of interstitial myocardial fibrosis and myocardial stiffening. Cardiac magnetic resonance (CMR) T₁-mapping is a novel tool, which allows noninvasive quantification of the extracellular space and diffuse myocardial fibrosis. This review provides an overview of the potential of myocardial tissue characterization with CMR T₁ mapping in HFpEF patients, outlining its diagnostic and prognostic implications and discussing future directions. We conclude that CMR T₁ mapping is potentially an effective tool for patient characterization in large-scale epidemiological, diagnostic, and therapeutic HFpEF trials beyond traditional imaging parameters.

Circulating Endothelial Cells and Endothelial Function Predict Major Adverse Cardiac Events and Early Adverse Left Ventricular Remodeling in Patients With ST-Segment Elevation Myocardial Infarction

Endothelial progenitor cells (EPCs) and circulating endothelial cells (CECs) are mobilized from the bone marrow and increase in the early phase after ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the prognostic significance of CECs and indices of endothelial dysfunction in patients with STEMI. In 78 patients with acute STEMI, characterization of CD34+/VEGFR2+CECs, and indices of endothelial damage/dysfunction such as brachial artery flow mediated dilatation (FMD) were determined. Blood samples for CECs assessment and quantification were obtained within 24 hours of admission and FMD was assessed during the index hospitalization. At 30 days follow up, the primary composite end point of major adverse cardiac events (MACE) consisting of all-cause mortality, recurrent nonfatal MI, or heart failure and the secondary endpoint of early adverse left ventricular (LV) remodeling were analyzed. The 17 patients (22%) who developed MACE had significantly higher CEC level (P = 0.004), von Willebrand factor (vWF) level (P = 0.028), and significantly lower FMD (P = 0.006) compared to the remaining patients. Logistic regression analysis showed that CECs level and LV ejection fraction were independent predictors of MACE. The areas under the receiver operating characteristic curves (ROC) for CEC level, FMD, and the logistic model with both markers were 0.73, 0.75, and 0.82, respectively, for prediction of the MACE. The 16 patients who developed the secondary endpoint had significantly higher CEC level compared to remaining patients (P = 0.038). In conclusion, increased circulating endothelial cells and endothelial dysfunction predicted the occurrence of major adverse cardiac events and adverse cardiac remodeling in patients with STEMI.

QRS complex distortion (Grade 3 ischaemia) as a predictor of myocardial damage assessed by cardiac magnetic resonance imaging and clinical prognosis in patients with ST-elevation myocardial infarction

AIMS

Distortion of the terminal portion of the QRS complex (so-called Grade 3 ischaemia, G3I) has been associated with adverse outcomes in ST-elevation myocardial infarction (STEMI) populations. However, the correlation of G3I with infarct size and microvascular injury as defined by cardiac magnetic resonance (CMR) is not well defined. Aim of this study was to assess the relation of G3I with myocardial damage as assessed by CMR and clinical outcomes in STEMI patients.

METHODS AND RESULTS

We analysed the ECGs of 572 consecutive STEMI patients regarding the presence or absence of G3I. CMR was performed within 1 week after infarction for comprehensive assessment of myocardial damage using a standardized protocol. The primary clinical endpoint was major adverse cardiac events (MACE) within 12 months after infarction. G3I was present in 186 (32%) patients. The presence of G3I was associated with larger infarct size (P = 0.01), the presence of late microvascular obstruction (P = 0.05), the presence of intramyocardial haemorrhage (P = 0.04), and impaired myocardial salvage (P = 0.01). G3I was associated with a higher incidence of MACE (P = 0.01) and was identified as an independent predictor of MACE in Cox regression analysis (HR 2.19; 95% CI 1.10 to 4.38, P = 0.03).

CONCLUSION

This largest study to date correlating G3I on the admission ECG with CMR markers of myocardial damage demonstrates that G3I is significantly associated with infarct size, impaired myocardial salvage, and reperfusion injury in a reperfused STEMI population. Moreover, G3I was independently associated with MACE. CLINICALTRIALS.GOV: NCT00712101.