Cardiac magnetic resonance derived left atrial function after ST-elevation myocardial infarction: an important prognostic indicator

Background

The prognostic value of cardiac magnetic resonance (CMR) derived left atrial (LA) strain, ejection fraction (LAEF) and volumes (LAVImax and LAVImin) after STEMI is controversial.

Aim

To assess the relationship between LA function and major adverse cardiovascular events (MACE) within 2 years after STEMI.

Methods

We prospectively recruited 213 consecutive STEMI patients who underwent CMR at median day 4. 202 patients had complete CMR data for feature tracking assessment. LA reservoir and booster strain were quantified by one blinded observer based on the average of three independently repeated measurements from two- and four-chamber views. MACE was a composite of all-cause mortality, reinfarction, new or worsening heart failure, stroke and sustained ventricular arrhythmias.

Results

The cohort included 174 (86.1%) males, median age 56 years (IQR 50–65 years). MACE occurred in 35 (17.3%) patients. Patients with MACE had lower median reservoir strain (18.9 vs 29.4%, p<0.001), booster strain (9.4 vs 13.0%, p=0.002) and LAEF (41.5 vs 49.2%, p<0.001), and higher LAVImax (43.5 vs 38.6ml/m2, p=0.019) and LAVImin (23.7 vs 19.3ml/m2, p<0.001) than patients without MACE. Patients with reduced left ventricular ejection fraction (LVEF≤40%) had lower median reservoir strain (22.5 vs 30.1%, p<0.001), booster strain (11.3 vs 12.9%, p=0.021) and LAEF (43.3 vs 50.3%, p<0.001) than patients with LVEF>40%. AUC analyses showed reservoir strain (AUC 0.769; 95% CI 0.676–0.861, p<0.001), booster strain (AUC 0.684; 95% CI 0.558–0.810, p=0.002) and LAEF (AUC 0.698; 95% CI 0.596–0.800, p<0.001) predicted MACE. Kaplan Meier analyses showed a difference in MACE between high- and low-risk groups for reservoir strain (cutoff 21%, p<0.001), booster strain (cutoff 9.6%, p<0.001) and LAEF (cutoff 41%, p<0.001). Univariate Cox regression analyses showed all LA parameters had a significant effect on MACE, while multivariate analyses found additional prognostic utility using reservoir strain.

Conclusion

LA reservoir strain provided incremental prognostic value beyond established clinical and CMR parameters for predicting MACE after STEMI.

Kaplan Meier analyses

Funding Acknowledgement

Type of funding source: None

4938Left ventricular global longitudinal strain recovery predicts scar size reduction and systolic remodelling post ST-elevation myocardial infarction

Background

Left ventricular (LV) strain has prognostic utility following ST-elevation myocardial infarction (STEMI); however, serial changes in LV strain has not been evaluated post-infarct. We sought to determine the relationship between post-STEMI transthoracic echocardiographic (TTE) LV global longitudinal strain (GLS) and cardiac magnetic resonance (CMR) imaging derived scar size and LV systolic remodelling.

Methods

Following revascularisation, 172 first STEMI patients (85% male, 56.9±10.7 years) had paired TTE for GLS, and CMR to evaluate scar size and LV systolic function at baseline (2–7 days) and follow-up (8–10 weeks). Patients were divided into 3 groups according to absolute baseline GLS: group 1 (GLS ≥16%), group 2 (12%< GLS <16%), group 3 (GLS ≤12%). GLS recovery was defined as ≥10% increase in GLS at follow-up, excluding patients with normal baseline GLS. LV systolic adverse remodelling was defined as ≥15% increase in LVESV. LV systolic reverse remodelling was defined as ≥15% decrease in LVESV. Scar reduction was defined as ≥30% decrease in scar size.

Results

Group 1 and 2 had smaller follow-up scar size and higher LVEF compared to group 3 (p<0.0001 for both, see table). There was no difference in scar size reduction or systolic reverse remodeling among the baseline GLS groups (p>0.05 for both). Importantly, no patients from group 1 demonstrated systolic adverse remodelling. Relative change in GLS is significantly correlated with changes in LVEF (r=0.354, p<0.0001) and scar size (r=−0.262, p<0.0001), see figure. On multivariate binary logistic analysis, patients who demonstrated GLS recovery had greater reduction in scar size (OR=2.77 (1.09–7.01), p=0.032) and LV systolic reverse remodelling (OR=9.63 (1.21–76.41), p=0.032).

Follow-up parameters within GLS groups All patients (n=172) Group 1 (n=47) Group 2 (n=72) Group 3 (n=53) Follow-up GLS, % 16.02±3.44 19.38±1.90 16.36±2.09 12.57±2.69 GLS recovery, n 110 (64%) 19 (40%) 53 (74%) 38 (72%) Follow-up scar size, % 7.67±5.40 5.01±3.38 6.27±3.73 12.02±6.24 Follow-up LVEF, % 51.80±10.20 57.83±6.95 54.14±8.02 43.26±9.83 Data presented as mean ± SD or n (%).

Correlation graphs for change in GLS

Conclusion

Stratification of STEMI patients by baseline GLS was a determinant of CMR scar size as well as LV systolic function. However, the evaluation of GLS recovery could provide additional insights into reduction in scar size and LV systolic remodelling, both important prognostic markers. Thus, echocardiographic serial GLS evaluation may be a relevant non-invasive parameter, that is cheaper and more widely available for monitoring STEMI patients and guiding therapy.

P1483Serial changes in peak left atrial strain predicts diastolic remodelling following percutaneous revascularisation for ST-segment elevation myocardial infarction

Background

Echocardiographic 2D speckle tracking peak left atrial (LA) strain reflects LA reservoir function. Limited studies have reported the relationship between peak LA strain and diastolic dysfunction. In addition, adverse diastolic remodeling (ADR) has been reported, to have better prognostic value than single diastolic function assessment following ST-elevation myocardial infarction (STEMI).

Purpose

We examined the relationship between serial changes in echocardiographic peak LA strain and diastolic function in STEMI patients.

Methods

186 percutaneously revascularized first presentation STEMI patients (87% male, 56.9±10.6 years) underwent serial TTE at baseline (2–7 days) and at follow-up (8–10 weeks) post-STEMI. Peak LA reservoir strain measurements were analysed from apical 2-, 3- and 4- chamber views. Diastolic function was graded as per 2016 guidelines: normal, grade 1, grade 2 and grade 3. ADR was defined as worsening of diastolic function grade (≥1) from baseline to follow-up, or persistent grade 3.

Results

Lower baseline peak LA strain was associated with grade 2 and grade 3 diastolic dysfunction compared to normal and grade 1 function at follow-up (p<0.05, see figure and table). Change in LA strain was less with worsening grades of diastolic function (see table). ADR was seen in 33 patients. Lower baseline peak LA strain predicted ADR (B=0.86 (0.80–0.92), p<0.0001). In addition, a reduction in peak LA strain at follow up was independently associated with ADR (B=0.91 (0.84–0.97), p=0.007) (see figure).

Diastolic function grades with LA strain Follow-up diastolic function Baseline peak LA strain (%) Follow-up peak LA strain (%) Change in peak LA strain (%) Normal (n=91) 35.70±6.38 40.97±8.10 5.26±6.07 Grade 1 (n=61) 30.70±6.97 34.54±8.77 3.84±6.32 Grade 2 (n=17) 23.95±6.11 25.49±5.93 1.54±4.70 Grade 3 (n=17) 23.66±8.07 23.49±10.64 −0.17±7.44 Data presented as mean ± SD.

Peak LA strain vs diastolic function

Conclusion

Peak LA strain is associated with diastolic function following STEMI and differentiates normal diastolic function from diastolic dysfunction. Serial changes in peak LA strain correlated with diastolic remodelling. Longer-term follow-up is required to determine the prognostic value of changes in peak LA strain, and diastolic remodelling.

Evidence-based management of heart failure in clinical practice: a review of device-based therapy use

BACKGROUND

Heart failure is a growing health issue and is associated with significant mortality risk. Device therapy is efficacious in preventing sudden death in patients with heart failure; however, this evidence comes from rigorous clinical trials. It is unclear how device therapy is utilized in 'real-world' practice. The primary objective was to characterize patterns of device use in patients with heart failure at risk of sudden death and to identify barriers to guideline-driven prescription of implantable cardioverter-defibrillators.

METHODS

We report a cross-sectional study of patients attending general cardiology clinic over a 3-month period.

RESULTS

Of 1003 consecutive patients attending the cardiology clinic, 176 had heart failure. Of these, 66 were potentially eligible for device therapy, but only 16 of these had actually undergone device implantation. Potentially eligible non-recipients were older (P < 0.001), more likely to have ischaemic cardiomyopathy (P= 0.002), less likely to be prescribed spironolactone (P= 0.005) or warfarin (P= 0.02), and less likely to have a widened QRS > 120 ms (P= 0.005). There was a high prevalence of underuse of evidence-based pharmacotherapies among patients with heart failure.

CONCLUSION

There is substantial underuse of device therapy in patients with heart failure. Strikingly, whereas patients with symptoms of heart failure were more likely to receive a device, those being managed for ischaemic heart disease were not. There is also a high prevalence of failure to prescribe evidence-based pharmacotherapy in a tertiary hospital general cardiology clinic. This may be explained in part by the lack of a patient database to record treatment contraindications and to alert clinicians to possible gaps in patient therapy.