Tor Biering-Sørensen

Global Longitudinal Strain Is a Superior Predictor of All-Cause Mortality in Heart Failure With Reduced Ejection Fraction

OBJECTIVES The purpose of this study was to investigate the prognostic value of global longitudinal strain (GLS) in heart failure with reduced ejection fraction (HFrEF) patients in relation to all-cause mortality. BACKGROUND Measurement of myocardial deformation by 2-dimensional speckle tracking echocardiography, specifically GLS, may be superior to conventional echocardiographic parameters, including left ventricular ejection fraction, in predicting all-cause mortality in HFrEF patients. METHODS Transthoracic echocardiographic examinations were retrieved for 1,065 HFrEF patients admitted to a heart failure clinic. The echocardiographic images were analyzed, and conventional and novel echocardiographic parameters were obtained. RESULTS Many of the conventional echocardiographic parameters proved to be predictors of mortality. However, GLS remained an independent predictor of mortality in the multivariable model after adjusting for age, sex, body mass index, total cholesterol, mean arterial pressure, heart rate, ischemic cardiomyopathy, percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, noninsulin dependent diabetes mellitus, and conventional echocardiographic parameters (hazard ratio [HR]: 1.15; 95% confidence interval [CI]: 1.04 to 1.27; p = 0.008, per 1% decrease). No other echocardiographic parameter remained an independent predictor after adjusting for these variables. Furthermore, GLS had the highest C-statistics of all the echocardiographic parameters and added incremental prognostic value with a significant increase in the net reclassification improvement (p = 0.009). Atrial fibrillation (AF) modified the relationship between GLS and mortality (p value for interaction = 0.036); HR: 1.08 (95% CI: 0.97 to 1.19), p = 0.150 and HR: 1.22 (95% CI: 1.15 to 1.29), p < 0.001, per 1% decrease in GLS for patients with and without AF, respectively. Sex also modified the relationship between GLS and mortality (p value for interaction = 0.047); HR: 1.23 (95% CI: 1.16 to 1.30), p < 0.001 and HR: 1.09 (95% CI: 0.99 to 1.20), p = 0.083, per 1% decrease in GLS for men and women, respectively. CONCLUSIONS GLS is an independent predictor of all-cause mortality in HFrEF patients, especially in male patients without AF. Furthermore, GLS was a superior prognosticator compared with all other echocardiographic parameters.

Myocardial Strain Analysis by 2-Dimensional Speckle Tracking Echocardiography Improves Diagnostics of Coronary Artery Stenosis in Stable Angina Pectoris

Background—Two-dimensional strain echocardiography detects early signs of left ventricular dysfunction; however, it is unknown whether myocardial strain analysis at rest in patients with suspected stable angina pectoris predicts the presence of coronary artery disease (CAD). Methods and Results—In total, 296 consecutive patients with clinically suspected stable angina pectoris, no previous cardiac history, and normal left ventricular ejection fraction were included. All patients were examined by 2-dimensional strain echocardiography, exercise ECG, and coronary angiography. Two-dimensional strain echocardiography was performed in the 3 apical projections. Peak regional longitudinal systolic strain was measured in 18 myocardial sites and averaged to provide global longitudinal peak systolic strain. Duke score, including ST-segment depression, chest pain, and exercise capacity, was used as the outcome of the exercise test. Patients with an area stenosis ≥70% in ≥1 epicardial coronary artery were categorized as having significant CAD (n=107). Global longitudinal peak systolic strain was significantly lower in patients with CAD compared with patients without (17.1±2.5% versus 18.8±2.6%; P<0.001) and remained an independent predictor of CAD after multivariable adjustment for baseline data, exercise test, and conventional echocardiography (odds ratio, 1.25 [P=0.016] per 1% decrease). Area under receiver operating characteristic curve for exercise test and global longitudinal peak systolic strain in combination was significantly higher than that for exercise test alone (0.84 versus 0.78; P=0.007). Furthermore, impaired regional longitudinal systolic strain identifies which coronary artery is stenotic. Conclusions—In patients with suspected stable angina pectoris, global longitudinal peak systolic strain assessed at rest is an independent predictor of significant CAD and significantly improves the diagnostic performance of exercise test. Furthermore, 2-dimensional strain echocardiography seems capable of identifying high-risk patients.

Cardiac Imaging to Evaluate Left Ventricular Diastolic Function

Left ventricular diastolic dysfunction in clinical practice is generally diagnosed by imaging. Recognition of heart failure with preserved ejection fraction has increased interest in the detection and evaluation of this condition and prompted an improved understanding of the strengths and weaknesses of different imaging modalities for evaluating diastolic dysfunction. This review briefly provides the pathophysiological background for current clinical and experimental imaging parameters of diastolic dysfunction, discusses the merits of echocardiography relative to other imaging modalities in diagnosing and grading diastolic dysfunction, summarizes lessons from clinical trials that used parameters of diastolic function as an inclusion criterion or endpoint, and indicates current areas of research.

Concordance and reproducibility between M-mode, tissue Doppler imaging, and two-dimensional strain imaging in the assessment of mitral annular displacement and velocity in patients with various heart conditions

AIMS Mitral annular (MA) displacement reflects longitudinal left ventricular (LV) deformation and systolic velocity measurements reflect the rate of contraction; both are valuable in the diagnosis and prognosis of cardiac disease. The aim of this study was to test the agreement and reproducibility between motion mode (M-mode), colour tissue Doppler imaging (TDI), and two-dimensional strain imaging (2DSI) when measuring MA displacement and systolic velocity. METHODS AND RESULTS Using GE Healthcare Vivid 7 and E9 and Echopac BT11 software, MA displacement and velocity measurements by 2DSI, TDI, and M-mode determined in the septal and lateral walls in the apical four-chamber view were assessed in 50 control subjects and in 168 patients with various cardiac anomalies known to affect longitudinal displacement such as heart failure, mitral regurgitation, LV hypertrophy, and LV dilation. Intra- and inter-observer variability were tested using the Bland-Altman method in 125 patients. A relatively low bias between M-mode and TDI with respect to MA displacement (mean difference ± 1.96 standard deviation: 0.08 ± 0.35 cm) and a low bias between TDI and 2DSI with respect to MA peak systolic velocity (-0.13 ± 1.87 cm/s) were found. Reproducibility was acceptable for all methods with TDI having the lowest intra- and inter-observer variability. CONCLUSION LV function could be assessed in terms of MA displacement and systolic velocity using M-mode, TDI, and 2DSI. None of the measurement techniques are, however, interchangeable. Overall, TDI seems to be the most robust method, having the lowest observer variability.

Global Electric Heterogeneity Risk Score for Prediction of Sudden Cardiac Death in the General Population: The Atherosclerosis Risk in Communities (ARIC) and Cardiovascular Health (CHS) Studies.

Background— Asymptomatic individuals account for the majority of sudden cardiac deaths (SCDs). Development of effective, low-cost, and noninvasive SCD risk stratification tools is necessary. Methods and Results— Participants from the Atherosclerosis Risk in Communities study and Cardiovascular Health Study (n=20 177; age, 59.3±10.1 years; age range, 44–100 years; 56% female; 77% white) were followed up for 14.0 years (median). Five ECG markers of global electric heterogeneity (GEH; sum absolute QRST integral, spatial QRST angle, spatial ventricular gradient [SVG] magnitude, SVG elevation, and SVG azimuth) were measured on standard 12-lead ECGs. Cox proportional hazards and competing risks models evaluated associations between GEH electrocardiographic parameters and SCD. An SCD competing risks score was derived from demographics, comorbidities, and GEH parameters. SCD incidence was 1.86 per 1000 person-years. After multivariable adjustment, baseline GEH parameters and large increases in GEH parameters over time were independently associated with SCD. Final SCD risk scores included age, sex, race, diabetes mellitus, hypertension, coronary heart disease, stroke, and GEH parameters as continuous variables. When GEH parameters were added to clinical/demographic factors, the C statistic increased from 0.777 to 0.790 (P=0.008), the risk score classified 10-year SCD risk as high (>5%) in 7.2% of participants, 10% of SCD victims were appropriately reclassified into a high-risk category, and only 1.4% of SCD victims were inappropriately reclassified from high to intermediate risk. The net reclassification index was 18.3%. Conclusions— Abnormal electrophysiological substrate quantified by GEH parameters is independently associated with SCD in the general population. The addition of GEH parameters to clinical characteristics improves SCD risk prediction.

Prognostic value of cardiac time intervals by tissue Doppler imaging M-mode in patients with acute ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention.

Background— Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI assessed by color tissue Doppler imaging M-mode through the mitral leaflet in patients with ST-segment–elevation myocardial infarction (MI) is unknown. Methods and Results— In total, 391 patients were admitted with an ST-segment–elevation MI, treated with primary percutaneous coronary intervention, and examined by echocardiography a median of 2 days after the ST-segment–elevation MI. Outcome was assessed according to death (n=33), hospitalization with heart failure (n=53), or new MI (n=25). Follow-up time was a median of 25 months. The population was stratified according to tertiles of the MPI. The risk of new MI, being admitted with congestive heart failure or death, increased with increasing tertile of MPI, being ≈3 times as high for the third tertile compared with the first tertile (hazard ratio, 2.8; 95% confidence interval, 1.7–4.7; P<0.001). MPI provided independent prognostic information in a multivariable Cox regression model adjusted for age, sex, previous MI, peak troponin, and systolic and diastolic echocardiographic parameters, with a hazard ratio of 1.24 (P=0.005) for the combined end point per each 0.1 increase in MPI. Conclusions— MPI assessed by tissue Doppler imaging M-mode is a simple and reproducible measure that provides independent prognostic information, regardless of rhythm, incremental to conventional and novel echocardiographic parameters of systolic and diastolic function in patients with ST-segment–elevation MI treated with primary percutaneous coronary intervention.

Usefulness of the Myocardial Performance Index Determined by Tissue Doppler Imaging M-Mode for Predicting Mortality in the General Population

The objective of this study was to evaluate the prognostic value of the myocardial performance index (MPI), assessed by color-coded tissue Doppler imaging (TDI) M-mode through the anterior mitral leaflet. Color TDI M-mode through the mitral leaflet is an easy, very fast, and precise method to estimate cardiac intervals and thus obtain the MPI, but the diagnostic and prognostic values of this parameter are unknown. In a large population study, cardiac function was evaluated in 1,100 participants by conventional echocardiography and TDI. MPI was calculated from pulse-wave Doppler analyses of left ventricular in- and outflow using standard procedures (MPI(conv)) and by color-coded TDI M-mode through the mitral leaflet in the apical 4-chamber view (MPI(TDI)). MPI(TDI) was increased in subjects with coronary heart disease (CHD) compared to controls, even after multivariable adjustment (p <0.002). During follow-up (median 5.3 years), 90 participants died. MPI(TDI) was significantly associated with overall mortality, and risk of dying increased by 31% per 0.1 increase in MPI(TDI). In contrast to MPI(conv), MPI(TDI) provided independent prognostic information in a multivariable Cox proportional hazard model (adjusting for age, gender, body mass index, heart rate, mean arterial blood pressure, and CHD), with a hazard ratio of 1.18 (p = 0.01) per 0.1 increase in MPI(TDI). In conclusion, MPI(TDI) is a quick, simple, and reproducible measurement, which is increased in subjects with CHD and provides independent prognostic information in a low-risk population.

Global Longitudinal Strain by Echocardiography Predicts Long-Term Risk of Cardiovascular Morbidity and Mortality in a Low-Risk General PopulationCLINICAL PERSPECTIVE: The Copenhagen City Heart Study

Background— Global longitudinal strain (GLS) is prognostic of adverse cardiovascular outcomes in various patient populations, but the prognostic utility of GLS for long-term cardiovascular morbidity and mortality in the general population is unknown. Methods and Results— A total of 1296 participants in a general population study underwent a health examination, including echocardiography measurement of GLS. The primary end point was the composite of incident heart failure, acute myocardial infarction, or cardiovascular death. During a median follow-up of 11 years, 149 (12%) participants were diagnosed with heart failure, acute myocardial infarction, or cardiovascular death. Lower GLS was associated with a higher risk of the composite end point (hazard ratio, 1.12; 95% confidence interval, 1.08–1.17; P<0.001 per 1% decrease), an association that persisted after multivariable adjustment for age, sex, heart rate, hypertension, systolic blood pressure, left ventricular ejection fraction, left ventricular mass index, left ventricular dimension, deceleration time, left atrium dimension, E/e′, and pro B-type natriuretic peptide (hazard ratio, 1.05; 95% confidence interval, 1.00–1.11; P=0.045 per 1% decrease). GLS provided incremental prognostic information beyond the Framingham Risk Score, the Systemic Coronary Evaluation risk chart, and the modified American College of Cardiology/American Heart Association Pooled Cohort Equation for the composite outcome and incident heart failure. Sex modified the relationship between GLS and outcome such that after multivariable adjustment, GLS was an independent predictor of outcomes in men but not in women (hazard ratio, 1.14; 95% confidence interval, 1.06–1.24; P=0.001, and hazard ratio, 0.99; 95% confidence interval, 0.92–1.07; P=0.81, respectively; P for interaction =0.032). Conclusions— In the general population, GLS provides independent and incremental prognostic information regarding long-term risk of cardiovascular morbidity and mortality. GLS seems to be a stronger prognosticator in men than in women.

Global Electric Heterogeneity Risk Score for Prediction of Sudden Cardiac Death in the General Population

Background— Asymptomatic individuals account for the majority of sudden cardiac deaths (SCDs). Development of effective, low-cost, and noninvasive SCD risk stratification tools is necessary. Methods and Results— Participants from the Atherosclerosis Risk in Communities study and Cardiovascular Health Study (n=20 177; age, 59.3±10.1 years; age range, 44–100 years; 56% female; 77% white) were followed up for 14.0 years (median). Five ECG markers of global electric heterogeneity (GEH; sum absolute QRST integral, spatial QRST angle, spatial ventricular gradient [SVG] magnitude, SVG elevation, and SVG azimuth) were measured on standard 12-lead ECGs. Cox proportional hazards and competing risks models evaluated associations between GEH electrocardiographic parameters and SCD. An SCD competing risks score was derived from demographics, comorbidities, and GEH parameters. SCD incidence was 1.86 per 1000 person-years. After multivariable adjustment, baseline GEH parameters and large increases in GEH parameters over time were independently associated with SCD. Final SCD risk scores included age, sex, race, diabetes mellitus, hypertension, coronary heart disease, stroke, and GEH parameters as continuous variables. When GEH parameters were added to clinical/demographic factors, the C statistic increased from 0.777 to 0.790 (P=0.008), the risk score classified 10-year SCD risk as high (>5%) in 7.2% of participants, 10% of SCD victims were appropriately reclassified into a high-risk category, and only 1.4% of SCD victims were inappropriately reclassified from high to intermediate risk. The net reclassification index was 18.3%. Conclusions— Abnormal electrophysiological substrate quantified by GEH parameters is independently associated with SCD in the general population. The addition of GEH parameters to clinical characteristics improves SCD risk prediction.

LA emptying fraction improves diagnosis of paroxysmal AF after cryptogenic ischemic stroke: results from the SURPRISE study.

In 25% of patients with ischemic stroke, no etiologic factor is identified: so-called cryptogenic strokes (CS) [(1)][1]. Asymptomatic paroxysmal atrial fibrillation (PAF) is often suspected to be the cause of stroke in these patients. Echocardiographic estimates of left atrial (LA) function, such