Prognostic Value of Multilayer Left Ventricular Global Longitudinal Strain in Patients with ST-segment Elevation Myocardial Infarction with Mildly Reduced Left Ventricular Ejection Fractions

Layer-Specific Strain Analysis in Patients with Dilated Cardiomyopathy

BACKGROUND/OBJECTIVES

This study aimed to evaluate layer-specific strain according to etiology and assess whether subtle changes in longitudinal and circumferential layer strain are involved in predicting cardiac mortality during a two-year follow-up in patients with dilated cardiomyopathy admitted with heart failure decompensation.

METHODS

97 patients with dilated cardiomyopathy and a left ventricle ejection fraction ≤ 40% were recruited, 51 with ischemic and 46 with nonischemic etiologies. Conventional and two-dimensional speckle-tracking echocardiography (2D-STE) were conducted in dilated cardiomyopathy patients with a compensated phase of heart failure before discharge. Layer-specific longitudinal and circumferential strain was assessed from the endocardium, mid-myocardium, and epicardium by two-dimensional (2D) speckle-tracking echocardiography. The gradient between the endocardium and epicardium was calculated.

RESULTS

Patients with nonischemic etiology of dilated cardiomyopathy presented smaller values of global and layer strain than patients in the ischemic group. GLS, GLSend, GLSend-GLSepi, CSPMend, CSPMend-CSPMepi, CSAP, CSAPend, and CSAPend-CSAPepi were the parameters with statistically significant decreased values in non-survivors compared with survivors. In multivariate analysis, only CSPMend showed an independent value in predicting mortality at two-year follow-up. Receiver operator curve analysis provided CSPMend of -10.8% as a cut-off value with a sensitivity of 80% and specificity of 61.05% in identifying the dilated cardiomyopathy and heart failure patients with a risk of death at two-year follow-up.

CONCLUSIONS

GLS, GCS, and layer-specific strain analysis showed decreased values in nonischemic compared with ischemic dilated cardiomyopathy and also in non-survivors compared with survivors. CSPMend was the most sensitive strain parameter to identify patients with increased mortality risk at two-year follow-up.

Incremental value of high-risk CMR attributes to predict adverse remodeling after ST-segment elevation myocardial infarction across LVEF categories

BACKGROUND

A couple of cardiac magnetic resonance (CMR) attributes strongly predict adverse remodeling after ST-segment elevation myocardial infarction (STEMI); however, the value of incorporating high-risk CMR attributes, particularly, in patients with non-reduced ejection fraction, remains undetermined. This study sought to evaluate the independent and incremental predictive value of a multiparametric CMR approach for adverse remodeling after STEMI across left ventricular ejection fraction (LVEF) categories.

METHODS

A total of 157 patients with STEMI undergoing primary percutaneous coronary intervention were prospectively enrolled. Adverse remodeling was defined as ≥20% enlargement in left ventricular end-diastolic volume from index admission to 3 months of follow-up.

RESULTS

Adverse remodeling occurred in 23.6% of patients. After adjustment for clinical risk factors, a stroke volume index <29.6 mL/m2, a global longitudinal strain >-7.5%, an infarct size >39.2%, a microvascular obstruction >4.9%, and a myocardial salvage index <36.4 were independently associated with adverse remodeling. The incidence of adverse remodeling increased with the increasing number of high-risk CMR attributes, regardless of LVEF (LVEF ≤ 40%: P = 0.026; 40% < LVEF < 50%: P = 0.001; LVEF ≥ 50%: P < 0.001). The presence of ≥4 high-risk attributes was an independent predictor of LV adverse remodeling (70.0% vs. 16.8%, adjusted OR 9.68, 95 CI% 3.25-28.87, P < 0.001). Furthermore, the number of high-risk CMR attributes had an incremental predictive value over reduced LVEF and baseline clinical risk factors (AUC: 0.81 vs. 0.68; P = 0.002).

CONCLUSIONS

High-risk CMR attributes showed a significant association with adverse remodeling after STEMI across LVEF categories. This imaging-based model provided incremental value for adverse remodeling over traditional clinical factors and LVEF.

Incremental prognostic utility of left ventricular and left atrial strains in coronary artery disease patients with reduced systolic function

OBJECTIVE

This study aimed to investigate the predictive value of left ventricular global longitudinal strain (GLS) and left atrial reservoir strain (LARS) on adverse events in chronic coronary artery disease (CAD) patients with reduced systolic function.

METHODS

A total of 192 consecutive patients clinically diagnosed with chronic CAD and left ventricular ejection fraction (LVEF) ≤ 50% were finally included. Multiple strain parameters were analyzed with speckle tracking echocardiography. The composite endpoint included all-cause mortality, rehospitalization due to heart failure, myocardial infarction, and stroke.

RESULTS

Patients experiencing the endpoint showed lower LVEF, lower absolute GLS and LARS than those without events. Both GLS (AUC = 0.82 [GLS] vs. 0.58 [LVEF], p < 0.001) and LARS (AUC = 0.71 [LARS] vs. 0.58 [LVEF], p = 0.033) were superior to LVEF in predicting adverse events. Multivariate cox regression analysis showed that both GLS (hazard ratio, 0.71; 95% CI, 0.63-0.79; p < 0.001) and LARS (hazard ratio, 0.96; 95% CI, 0.93-0.98; p < 0.001) were independent predictors for the endpoint. The addition of LARS (global chi-squared, 35.7 vs. 17.4; p < 0.05), GLS (global chi-squared, 58.6 vs. 17.4; p < 0.05) or both LARS and GLS (global chi-squared, 79.6 vs. 17.4; p < 0.05) to LVEF in the prediction model significantly improved its performance. The same significant improvement was also shown in the subgroups of mild (30% < LVEF ≤ 50%) and severe (LVEF ≤ 30%) reduced systolic function.

CONCLUSIONS

Regarding CAD patients with reduced LVEF, both GLS and LARS are superior to LVEF in predicting adverse events, providing significant incremental value to LVEF.

Effects of Long-Term Carvedilol Therapy in Patients With ST-Segment Elevation Myocardial Infarction and Mildly Reduced Left Ventricular Ejection Fraction

The benefits of long-term oral β-blocker therapy in patients with ST-segment elevation myocardial infarction (STEMI) with mildly reduced left ventricular ejection fraction (LVEF; ≥40%) are still unknown. We sought to evaluate the efficacy of β-blocker therapy in patients with STEMI with mildly reduced LVEF. In the CAPITAL-RCT (Carvedilol Post-Intervention Long-Term Administration in Large-Scale Randomized Controlled Trial), patients with STEMI with successful percutaneous coronary intervention with an LVEF of ≥40% were randomly assigned to carvedilol or no β-blocker therapy. Among 794 patients, 280 patients had an LVEF of <55% at baseline (mildly reduced LVEF stratum), whereas 514 patients had an LVEF of ≥55% at baseline (normal LVEF stratum). The primary end point was a composite of all-cause death, myocardial infarction, hospitalization for acute coronary syndrome, and hospitalization for heart failure, and the secondary end point was a cardiac composite outcome: a composite of cardiac death, myocardial infarction, and hospitalization for heart failure. The median follow-up period was 3.7 years. The lower risk of carvedilol therapy relative to no β-blocker therapy was not significant for the primary end point in either the mildly reduced or normal LVEF strata. However, it was significant for the cardiac composite end point in the mildly reduced LVEF stratum (0.82/100 person-years vs 2.59/100 person-years, hazard ratio 0.32 [0.10 to 0.99], p = 0.047) but not in the normal LVEF stratum (1.48/100 person-years vs 1.06/100 person-years, hazard ratio 1.39 [0.62 to 3.13], p = 0.43, p for interaction = 0.04). In conclusion, long-term carvedilol therapy in patients with STEMI with primary percutaneous coronary intervention might be beneficial for preventing cardiac-related events in those with a mildly reduced LVEF.

Long-term mortality after acute coronary syndromes among patients with normal, mildly reduced, or reduced ejection fraction

AIMS

Left ventricular ejection fraction (LVEF) ≤ 40% is a well-established risk factor for mortality after acute coronary syndromes (ACS). However, the long-term prognostic impact of mildly reduced ejection fraction (EF) (LVEF 41-49%) after ACS remains less clear.

METHODS AND RESULTS

This was a retrospective study enrolling patients admitted with ACS included in a single-centre databank. LVEF was assessed by echocardiography during index hospitalization. Patients were divided in the following categories according to LVEF: normal (LVEF ≥ 50%), mildly reduced (LVEF 41-49%), and reduced (LVEF ≤ 40%). The endpoint of interest was all-cause death after hospital discharge. A multivariable Cox model was used to adjust for confounders. A total of 3200 patients were included (1952 with normal EF, 375 with mildly reduced EF, and 873 with reduced EF). The estimated cumulative incidence rates of mortality at 10 years for patients with normal, mildly reduced, and reduced EF were 24.8%, 33.5%, and 41.3%, respectively. After adjustments, the presence of reduced EF was associated with higher mortality compared with normal EF [adjusted hazard ratio (HR) 1.64; 95% confidence interval (CI) 1.36-1.96; P < 0.001], as was mildly reduced EF compared with normal EF (adjusted HR 1.33; 95% CI 1.05-1.68; P = 0.019). The presence of reduced EF was not associated with a statistically significantly higher mortality compared with mildly reduced EF (adjusted HR 1.23; 95% CI 0.96-1.57; P = 0.095).

CONCLUSIONS

In patients with ACS, mildly reduced EF measured in the acute phase was associated with higher long-term mortality compared with patients with normal EF. These data emphasize the importance of anti-remodelling therapies for ACS patients who have LVEF in the mildly reduced range.