Left Atrial Strain Predicts Subclinical Atrial Fibrillation Detected by Long-term Continuous Monitoring in Elderly High-Risk Individuals

BACKGROUND

Left atrial (LA) speckle tracking provides detailed information on atrial function. Its utility for predicting subclinical atrial fibrillation (SCAF) is unclear. Therefore, we sought to investigate whether LA strain measures could predict SCAF detected by long-term continuous rhythm monitoring.

METHODS

This was an echocardiographic substudy of the LOOP study, where elderly at risk of stroke were randomized to receive a loop recorder (Reveal LINQ) or control. Participants who received a loop recorder were included in this analysis. Echocardiography included LA reservoir, conduit, and contraction strain. Participants were followed with continuous rhythm monitoring for SCAF (≥6 minutes). Cox proportional hazards regression was applied to adjust for atrial fibrillation risk factors.

RESULTS

In total, 956 participants were eligible for analysis. Median continuous rhythm monitoring was 35 months (IQR, 20-40 months), during which 278 (29%) were diagnosed with SCAF. The mean age was 74 years, 56% were male, median CHA2DS2-VASc-score was 4. LA reservoir strain was an independent predictor of SCAF after multivariable adjustments (HR, 1.04 [1.02-1.05], per 1% decrease) and so was contraction strain. The findings were unchanged in competing risk analyses and in participants with normal LA size and diastolic function. Participants with low reservoir strain (<33%) had a significantly higher risk of SCAF compared with those with high reservoir strain (incidence rate, 14.5 [12.4-16.9] versus 9.8 [8.2-11.8] events/100 person-years). The same was noted for low versus high contraction strain.

CONCLUSIONS

LA reservoir and contraction strain are independent predictors of SCAF in elderly at risk of stroke. This also applies to individuals with normal LA size and diastolic function.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02036450.

A pilot study for risk stratification of ventricular tachyarrhythmia in hypertrophic cardiomyopathy with routine echocardiography parameters

Ventricular tachyarrhythmia (VTA) are frequent arrhythmias in patients with hypertrophic cardiomyopathy (HCM). Representing a major risk factor for sudden cardiac death, Holter ECG at first clinical presentation appears insufficient. This study aims to investigate the ability of routinely obtained parameters associated with myocardial remodeling in stratifying for VTA in HCM. In this monocentric analysis, patients with HCM underwent 12-channel electrocardiography and echocardiography, including tissue doppler imaging. The study's primary endpoint was the documentation of non-sustained and sustained ventricular tachycardia-summarized as ventricular tachyarrhythmias (VTA) on Holter ECG or active devices. The occurrence of VTA was exploratory. Based on our collective, we developed a risk model regarding VTA. Of 140 HCM patients, 38 (27.1%) had an episode of VTA. Patients with VTA were likelier to have a history of atrial fibrillation (p < 0.001), a thicker interventricular septum (p < 0.001) and lower peak systolic mitral annular velocity (p < 0.001). The parameters were independently associated with endpoint in univariate and multivariate logistic regression. We created a logistic equation and calculated a cut-off value. The resulting ROC curve revealed a discriminative ability with AUC of 0.80 (sensitivity, 63%; specificity, 88%). Our risk model including these widely available parameters is able to distinguish low and high-risk of VTA in patients with HCM.

Reduced inferior wall longitudinal strain is associated with malignant arrhythmias in non-ischemic heart failure

BACKGROUND

Reduced systolic myocardial function in the inferior region of the left ventricle has been suggested to be associated with malignant arrhythmias. We tested this hypothesis in patients with non-ischemic heart failure.

METHODS

Patients with non-ischemic heart failure (left ventricular ejection fraction [LVEF] < 35%) were evaluated by 2D-speckle-tracking echocardiography. The regional longitudinal strain was calculated for each of the six left ventricular walls. The reduced regional function was defined as strain below the median. The outcome was a composite of sudden cardiac death, admission with sustained ventricular arrhythmia, resuscitated cardiac arrest, and appropriate therapy from a primary prophylactic implantable cardioverter defibrillator. Time-to-first-event analysis was performed using a Cox model.

RESULTS

From two centers, 401 patients were included (median age: 63 years, 72% male) with a median LVEF of 25% (interquartile range [IQR] 20;30), and a median inferior wall strain of -9.0% (-12.5; -5.4). During a median follow-up of 4.0 years, 52 outcomes occurred. After multivariate adjustment for clinical and electrocardiographic parameters, inferior wall strain was independently associated with the outcome (HR 2.50 [1.35; 4.62], p = .003). No independent association was found between the composite outcome and reduced strain in any of the other left ventricular walls, Global Longitudinal Strain (HR 1.66 [0.93; 2.98], p = .09), or LVEF (HR 1.33 [0.75; 2.33], p = .33).

CONCLUSIONS

Below median strain in the left ventricular inferior region was independently associated with a 2.5-fold increase in the risk of malignant arrhythmias and sudden cardiac death in patients with non-ischemic heart failure.

Predicting Malignant Ventricular Arrhythmias Using Real-Time Remote Monitoring

BACKGROUND

Although implantable cardioverter-defibrillator (ICD) therapies are associated with increased morbidity and mortality, the prediction of malignant ventricular arrhythmias has remained elusive.

OBJECTIVES

The purpose of this study was to evaluate whether daily remote-monitoring data may predict appropriate ICD therapies for ventricular tachycardia or ventricular fibrillation.

METHODS

This was a post hoc analysis of IMPACT (Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices), a multicenter, randomized, controlled trial of 2,718 patients evaluating atrial tachyarrhythmias and anticoagulation for patients with heart failure and ICD or cardiac resynchronization therapy with defibrillator devices. All device therapies were adjudicated as either appropriate (to treat ventricular tachycardia or ventricular fibrillation) or inappropriate (all others). Remote monitoring data in the 30 days before device therapy were utilized to develop separate multivariable logistic regression and neural network models to predict appropriate device therapies.

RESULTS

A total of 59,807 device transmissions were available for 2,413 patients (age 64 ± 11 years, 26% women, 64% ICD). Appropriate device therapies (141 shocks, 10 antitachycardia pacing) were delivered to 151 patients. Logistic regression identified shock lead impedance and ventricular ectopy as significantly associated with increased risk of appropriate device therapy (sensitivity 39%, specificity 91%, AUC: 0.72). Neural network modeling yielded significantly better (P < 0.01 for comparison) predictive performance (sensitivity 54%, specificity 96%, AUC: 0.90), and also identified patterns of change in atrial lead impedance, mean heart rate, and patient activity as predictors of appropriate therapies.

CONCLUSIONS

Daily remote monitoring data may be utilized to predict malignant ventricular arrhythmias in the 30 days before device therapies. Neural networks complement and enhance conventional approaches to risk stratification.

Sex-Specific Prevalence, Incidence, and Mortality Associated With Atrial Fibrillation in Heart Failure

OBJECTIVES

This study sought to investigate the mortality associated with atrial fibrillation (AF) in men and women with heart failure (HF) according to the sequence of presentation and rhythm versus rate control.

BACKGROUND

The sex-specific epidemiology of AF in HF is sparse.

METHODS

Using the Danish nationwide registries, all first-time cases of HF were identified and followed for all-cause mortality from 1998 to 2018.

RESULTS

Among 252,988 patients with HF (mean age: 74 ± 13 years, 45% women), AF presented before HF in 54,064 (21%) and on the same day in 27,651 (11%) individuals, similar in women and men. Among patients without AF, the cumulative 10-year incidence of AF was 18.7% (95% confidence interval [CI]: 18.2% to 19.1%) in women and 21.3% (95% CI: 21.0% to 21.6%) in men. On follow-up (mean: 6.2 ± 5.8 years), adjusted mortality rate ratios were 3.33 (95% CI: 3.25 to 3.41) in women and 2.84 (95% CI: 2.78 to 2.90) in men if AF antedated HF, 3.45 (95% CI: 3.37 to 3.56) in women versus 2.76 (95% CI: 2.69 to 2.83) in men when AF and HF were diagnosed concomitantly, and 4.85 (95% CI: 4.73 to 4.97) in women versus 3.89 (95% CI: 3.80 to 3.98) in men when AF developed after HF. Compared with rate control for AF, a rhythm-controlling strategy was associated with lowered mortality in inverse probability-weighted models across all strata and in both sexes (hazard ratios: 0.75 to 0.83), except for women who developed AF after HF onset (hazard ratio: 1.03).

CONCLUSIONS

More than half of all men and women with HF will develop AF during their clinical course, with prognosis associated with AF being worse in women than men. Further studies are needed to understand the underlying mechanisms.

Prognostic Value and Interplay Between Myocardial Tissue Velocities in Patients Undergoing Coronary Artery Bypass Grafting

Early diastolic tissue velocity (e') by tissue Doppler imaging represents an early marker of left ventricular (LV) dysfunction in ischemic heart disease. We assessed the value of e' for predicting mortality in patients undergoing coronary artery bypass grafting (CABG). We retrospectively investigated patients treated with CABG between 2006-2011. Before surgery, all patients underwent an echocardiogram with tissue Doppler imaging to measure tissue velocities: systolic (s'), e', and late diastolic (a'). The primary outcome was all-cause mortality. Survival analysis was applied. Improvement of EuroSCORE-II was assessed by net reclassification index. Of 660 patients, 72 (11%) died during a median follow-up time of 3.8 years. Mean age was 68 years, LVEF 50%, and 84% were men. All tissue velocities showed a significant negative association with outcome and e' provided highest Harrell's C-statistics (c-stat=0.68). After multivariable adjustment for EuroSCORE-II, LV hypertrophy, LV internal diameter, and global longitudinal strain, declining e' was associated with a higher risk of mortality (HR=1.35 (1.12 to 1.61), p = 0.001, per 1cm/s absolute decrease). LVEF≤40% modified the relationship between both s' and e' and outcome (p for interaction=0.021 and 0.024, respectively), such that neither predicted mortality when LVEF was ≤40%. In patients with LVEF>40%, only e' remained a predictor after multivariable adjustments (HR=1.36 (1.10 to 1.69), p = 0.005, per 1cm/s absolute decrease). A net reclassification index improvement of 0.14 was observed when adding global e' to the EuroSCORE-II. In conclusion, e' is an independent predictor of all-cause mortality in patients undergoing CABG, especially in patients with LVEF>40%, and improves the predictive value of EuroSCORE-II.

Left bundle branch block without a typical contraction pattern is associated with increased risk of ventricular arrhythmias in cardiac resynchronization therapy patients

Cardiac resynchronization therapy (CRT) reduces the risk of ventricular arrhythmias (VA) in heart failure (HF) patients with left bundle branch block (LBBB) while the effect is less clear among non-LBBB patients. This study aimed to investigate if absence of LBBB features whether by echocardiography or strict ECG criteria would identify patients at risk of developing VA in a cohort with LBBB according to conventional ECG criteria. Two hundred six CRT candidates were prospectively included from 2 centers. Prior to CRT presence of a typical LBBB contraction pattern was identified using longitudinal strain in the apical 4-chamber view. All preimplantation ECGs were categorized as LBBB or non-LBBB according to Strauss´ strict criteria. Primary end-point was defined as any appropriate antitachycardia pacing (ATP) or shock therapy within 2 years after CRT implantation. A total of 129 (63%) patients had a typical LBBB contraction pattern, while 134 (66%) met the strict ECG criteria. Over 2 years, 45 patients (22%) experienced VA. Absence of a typical LBBB contraction pattern was independently associated with an increased risk of VA (hazard ratio ([HR] 1.89; 95% CI 1.04 to 3.44; p: 0.036). Strict LBBB was not independently associated with the occurrence of VA. Fulfilling neither strict ECG nor echocardiographic criteria for LBBB was associated with a 3.3-fold increase in risk of VA ([HR] 3.34; 95% CI 1.75 to 6.94; (p < 0.001). The risk of VA was almost 2-fold higher if a typical LBBB contraction pattern was absent prior to CRT.

Role of confirmed and potential predictors of an unfavorable outcome in heart failure in everyday clinical practice

Heart failure (HF) is the only cardiovascular disease with an ever increasing incidence. HF, through reduced functional capacity, frequent exacerbations of disease, and repeated hospitalizations, results in poorer quality of life, decreased work productivity, and significantly increased costs of the public health system. The main challenge in the treatment of HF is the availability of reliable prognostic models that would allow patients and doctors to develop realistic expectations about the prognosis and to choose the appropriate therapy and monitoring method. At this moment, there is a lack of universal parameters or scales on the basis of which we could easily capture the moment of deterioration of HF patients’ condition. Hence, it is crucial to identify such factors which at the same time will be widely available, cheap, and easy to use. We can find many studies showing different predictors of unfavorable outcome in HF patients: thorough assessment with echocardiography imaging, exercise testing (e.g., 6-min walk test, cardiopulmonary exercise testing), and biomarkers (e.g., N-terminal pro-brain type natriuretic peptide, high-sensitivity troponin T, galectin-3, high-sensitivity C-reactive protein). Some of them are very promising, but more research is needed to create a specific panel on the basis of which we will be able to assess HF patients. At this moment despite identification of many markers of adverse outcomes, clinical decision-making in HF is still predominantly based on a few basic parameters, such as the presence of HF symptoms (NYHA class), left ventricular ejection fraction, and QRS complex duration and morphology.

Prognostic value of left ventricular mitral annular longitudinal displacement obtained by tissue Doppler imaging in patients with heart failure with reduced ejection fraction

Background

Tissue Doppler imaging (TDI) can be used to measure the mitral annular longitudinal displacement (LD) during systole. However, the prognostic utility of global and regional LD in patients with heart failure with reduced ejection fraction (HFrEF) is unknown.

Methods

Echocardiographic examinations from 907 patients with HFrEF were analysed obtaining conventional echocardiographic measurements. Regional LD was obtained from colour TDI projections in six mitral annular regions and global LD was calculated as an average.

Results

Mean age was 67 years, 26.9% were women and mean left ventricular ejection fraction was 27%. During a median follow-up period of 40 months, 150 (16.5 %) patients died. The risk of dying increased with decreasing tertile of global LD and was approximately five times higher for patients in the lowest tertile compared with the highest (1. tertile vs 3. tertile, HR 4.9, 95% CI: 3.0 to 7.9, p<0.001).

Global LD was a significant independent predictor of mortality after adjusting for age, gender, body mass index, pacemaker, heart rate, atrial fibrillation, diabetes and conventional echocardiographic measures and global longitudinal strain: HR 1.16 (95% CI: 1.00 to 1.34, p=0.044) per 1 mm decrease.

For regional measures, inferior LD was also a significant independent predictor in the multivariable model: HR 1.16 (95% CI: 1.04 to 1.29, p=0.006) and adding inferior LD to the conventional measures yielded a significant increase in Harrell’s C-statistic (95% CI: 0.75 to 0.78, p=0.009).

Conclusion

In patients with HFrEF, global and inferior LD are independent predictors of all-cause mortality. Furthermore, inferior LD proved to be a significant prognosticator when compared with all the conventional echocardiographic parameters.

Tissue Doppler-Derived Left Ventricular Systolic Velocity Is Associated with Lethal Arrhythmias in Cardiac Device Recipients Irrespective of Left Ventricular Ejection Fraction

BACKGROUND

Life-threatening arrhythmias (LTAs) can trigger sudden cardiac death or provoke implantable cardioverter-defibrillator (ICD) discharges that escalate morbidity and mortality. Longitudinal myofibrils predominate in the subendocardium, which is uniquely sensitive to arrhythmogenic triggers. In this study, we test the hypothesis that mitral annular systolic velocity (S'), a simple routinely obtained tissue Doppler index of LV long-axis systolic function, might predict lethal arrhythmias irrespective of left ventricular ejection fraction (LVEF).

METHODS

This is a retrospective analysis of data from 302 patients (mean age, 68 years; LVEF, 32%; 77% male; 52% ischemic; 35% primary prevention; and 53% cardiac resynchronization therapy defibrillator [CRT-D]) who were followed up (median, 15 months) at two centers after receipt of an ICD or CRT-D for diverse indications. S', averaged from tissue Doppler-derived medial and lateral mitral annular velocities, was correlated with the primary outcome of time to sustained ventricular tachycardia (VT) or fibrillation (VF) needing device therapy.

RESULTS

The median S' was 5.1 (interquartile range, 4.0-6.2) cm/sec and lower in CRT-D than ICD subjects (4.5 [3.8-5.6] cm/sec vs 5.5 [4.8-6.8] cm/sec, P < .001). Fifty-six (19%) subjects had LTA. Each 1 cm/sec higher S' correlated to a 30% decreased risk of LTA (hazard ratio = 0.70; 95% CI, 0.57-0.87; P = .001) independently of age, sex, β-blocker use, center, ICD use, and LVEF. Adding S' to the baseline Cox model improved net reclassification (P = .02). An S' > 5.6 cm/sec was the best cutoff and linked to a 58% lower LTA risk than an S' ≤ 5.6 cm/sec (95% CI, 0.23-0.85; P = .02).

CONCLUSIONS

A higher S' is associated with a reduced probability of LTA in cardiac device recipients irrespective of LVEF and may have the potential to be used clinically to titrate medical, device, and ablative therapies to mitigate future arrhythmic risk.

Association of the low e' and high E/e' with long-term outcomes in patients with normal ejection fraction: a hospital population-based observational cohort study

OBJECTIVE

We aimed to evaluate the association of the severity of left ventricular (LV) diastolic dysfunction with long-term outcomes in patients with normal ejection fraction.

DESIGN

Retrospective study.

SETTING

A single centre in Japan.

PARTICIPANTS

We included 3576 patients who underwent both scheduled transthoracic echocardiography and ECG between 1 January and 31 December 2013, in a hospital-based population after excluding valvular diseases or low ejection fraction (<50%) or atrial fibrillation and categorised them into three groups: septal tissue Doppler early diastolic mitral annular velocity (e')≥7 (without relaxation disorder, n=1593), e'<7 and early mitral inflow velocity (E)/e'≤14 (with relaxation disorder and normal LV end-diastolic pressure, n=1337) and e'<7 and E/e'>14 (with relaxation disorder and high LV end-diastolic pressure, n=646).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was a composite of all-cause death and major adverse cardiac events (MACE). The secondary outcome measure were all-cause death and MACE, separately.

RESULTS

The cumulative 3-year incidences of the primary outcome measures were significantly higher in the e'<7 and E/e'≤14 (19.0%) and e'<7 and E/e'>14 group (23.4%) than those for the e'≥7 group (13.0%; p<0.001). After adjusting for confounders, the excess 3-year risk of primary outcome for the groups with e'<7 and E/e'≤14 related to e'≥7 (HR: 1.24; 95% CI 1.02 to 1.52) and e'<7 and E/e'>14 related to e'<7 (HR: 1.57; 95% CI 1.28 to 1.94) were significant. The severity of diastolic dysfunction was associated with incrementally higher risk for primary outcomes (p<0.001).

CONCLUSION

The severity of LV diastolic dysfunction using e'<7 and E/e'>14 was associated with the long-term prognosis in patients with normal ejection fraction in an incremental fashion.

Association of cardiovascular magnetic resonance-derived circumferential strain parameters with the risk of ventricular arrhythmia and all-cause mortality in patients with prior myocardial infarction and primary prevention implantable cardioverter defibrillator

BACKGROUND

Impaired left ventricular (LV) contraction and relaxation may further promote adverse remodeling and may increase the risk of ventricular arrhythmia (VA) in ischemic cardiomyopathy. We aimed to examine the association of cardiovascular magnetic resonance (CMR)-derived circumferential strain parameters for LV regional systolic function, LV diastolic function and mechanical dispersion with the risk of VA in patients with prior myocardial infarction and primary prevention implantable cardioverter defibrillator (ICD).

METHODS

Patients with an ischemic cardiomyopathy who underwent CMR prior to primary prevention ICD implantation, were retrospectively identified. LV segmental circumferential strain curves were extracted from short-axis cine CMR. For LV regional strain analysis, the extent of moderately and severely impaired strain (percentage of LV segments with strain between - 10% and - 5% and > - 5%, respectively) were calculated. LV diastolic function was quantified by the early and late diastolic strain rate. Mechanical dispersion was defined as the standard deviation in delay time between each strain curve and the patient-specific reference curve. Cox proportional hazard ratios (HR) (95%CI) were calculated to assess the association between LV strain parameters and appropriate ICD therapy.

RESULTS

A total of 121 patients (63 ± 11 years, 84% men, LV ejection fraction (LVEF) 27 ± 9%) were included. During a median (interquartile range) follow-up of 47 (27;69) months, 30 (25%) patients received appropriate ICD therapy. The late diastolic strain rate (HR 1.1 (1.0;1.2) per - 0.25 1/s, P = 0.043) and the extent of moderately impaired strain (HR 1.5 (1.0;2.2) per + 10%, P = 0.048) but not the extent of severely impaired strain (HR 0.9 (0.6;1.4) per + 10%, P = 0.685) were associated with appropriate ICD therapy, independent of LVEF, late gadolinium enhancement (LGE) scar border size and acute revascularization. Mechanical dispersion was not related to appropriate ICD therapy (HR 1.1 (0.8;1.6) per + 25 ms, P = 0.464).

CONCLUSIONS

In an ischemic cardiomyopathy population referred for primary prevention ICD implantation, the extent of moderately impaired strain and late diastolic strain rate were associated with the risk of appropriate ICD therapy, independent of LVEF, scar border size and acute revascularization. These findings suggest that disturbed LV contraction and relaxation may contribute to an increased risk of VA after myocardial infarction.

Echo and heart failure: when do people need an echo, and when do they need natriuretic peptides?

Heart failure (HF) is a threat to public health. Heterogeneities in aetiology and phenotype complicate the diagnosis and management of HF. This is especially true when considering HF with preserved ejection fraction (HFpEF), which makes up 50% of HF cases. Natriuretic peptides may aid in establishing a working diagnosis in patients suspected of HF, but echocardiography remains the optimal choice for diagnosing HF. Echocardiography provides important prognostic information in both HF with reduced ejection fraction (HFrEF) and HFpEF. Traditionally, emphasis has been put on the left ventricular ejection fraction (LVEF). LVEF is useful for both diagnosis and prognosis in HFrEF. However, echocardiography offers more than this single parameter of systolic function, and for optimal risk assessment in HFrEF, an echocardiogram evaluating systolic, diastolic, left atrial and right ventricular function is beneficial. In this assessment echocardiographic modalities such as global longitudinal strain (GLS) by 2D speckle-tracking may be useful. LVEF offers little value in HFpEF and is neither helpful for diagnosis nor prognosis. Diastolic function quantified by E/e′ and systolic function determined by GLS offer prognostic insight in HFpEF. In HFpEF, other parameters of cardiac performance such as left atrial and right ventricular function evaluated by echocardiography also contribute with prognostic information. Hence, it is important to consider the entire echocardiogram and not focus solely on systolic function. Future research should focus on combining echocardiographic parameters into risk prediction models to adopt a more personalized approach to prognosis instead of identifying yet another echocardiographic biomarker.

Multimodality Cardiac Imaging for the Assessment of Left Atrial Function and the Association With Atrial Arrhythmias

Several cardiac imaging modalities are able to visualize the left atrium (LA) and, therefore, allow for quantification of both structural and functional properties of this cardiac chamber. In echocardiography, only the maximal LA volume is included in the assessment of diastolic function at the current moment. Numerous studies, however, have shown that functional measures may be superior to the maximal LA volume in several aspects and to possess clinical value even in the absence of structural abnormalities. Such functional measures could prove particularly useful in the setting of predicting atrial fibrillation, which will be a point of focus in this review. Pivotal cardiac magnetic resonance imaging studies have revealed high correlation between LA fibrosis and risk of atrial fibrillation recurrence after catheter ablation, and subsequent multimodality imaging studies have uncovered an inverse relationship between LA reservoir function and degree of LA fibrosis. This has sparked an increased interest into the application of advanced imaging modalities, including both speckle tracking echocardiography and tissue tracking by cardiac magnetic resonance imaging. Even though increasing evidence has supported the use of functional measures and proven its superiority to the maximal LA volume, they have still not been adopted in clinical guidelines. The reason for this discrepancy may rely on the fact that there is little to no agreement on how to technically perform deformation analysis of the LA. Such technical considerations, limitations, and alternate imaging prospects will be addressed in this review.

Prognostic importance of left ventricular mechanical dyssynchrony in heart failure with preserved ejection fraction

AIMS

Left ventricular mechanical dyssynchrony has been described in heart failure with preserved ejection fraction (HFpEF), but its prognostic significance is not known.

METHODS AND RESULTS

Of 3445 patients with HFpEF enrolled in the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist (TOPCAT) trial, dyssynchrony analysis was performed on 424 patients (12%) by multiple speckle tracking echocardiography strain-based criteria. The primary dyssynchrony analysis was the standard deviation of the time to peak longitudinal strain (SD T2P LS). Cox proportional hazards models assessed the association of dyssynchrony with the composite outcome of cardiovascular death or heart failure hospitalization. Mean age was 70 ± 10 years, LVEF was 60 ± 8%, and QRS duration was 101 ± 27 ms. Worse dyssynchrony, reflected in SD T2P LS, was associated with wider QRS, prior myocardial infarction, larger LV volume and mass, and worse systolic (lower LVEF and global longitudinal strain) and diastolic (lower e' and higher E/e') function. During a median follow-up of 2.6 (interquartile range 1.5-3.8) years, 107 patients experienced the composite outcome. Worse dyssynchrony was associated with the composite outcome in unadjusted analysis [hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.07; P = 0.021, per 10 ms increase], but not after adjusting for clinical characteristics, or after further adjustment for LVEF, AF, NYHA class, stroke, heart rate, creatinine, haematocrit, and QRS duration (HR 1.03, 95% CI 0.99-1.06; P = 0.16, per 10 ms increase).

CONCLUSION

Worse LV mechanical dyssynchrony, assessed by speckle tracking echocardiography, is not an independent predictor of adverse outcomes in HFpEF, suggesting that mechanical dyssynchrony is unlikely to be an important mechanism underlying this syndrome. These findings warrant validation in an independent study specifically designed to assess the prognostic utility of mechanical dyssynchrony in HFpEF.

TRIAL REGISTRATION

NCT00094302.

Regional Longitudinal Deformation Improves Prediction of Ventricular Tachyarrhythmias in Patients With Heart Failure With Reduced Ejection Fraction

Background—

Left ventricular dysfunction is a known predictor of ventricular arrhythmias. We hypothesized that measures of regional longitudinal deformation by speckle-tracking echocardiography predict ventricular tachyarrhythmias and provide incremental prognostic information over clinical and conventional echocardiographic characteristics.

Methods and Results—

We studied 1064 patients enrolled in the MADIT-CRT trial (Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy) with speckle-tracking data available. Peak longitudinal strain was obtained for the septal, lateral, anterior, and inferior myocardial walls at baseline. The end point was the first event of ventricular tachycardia (VT) or fibrillation (VF). During the median follow-up of 2.9 years, 254 (24%) patients developed VT/VF. Patients with VT/VF had significantly lower left ventricular ejection fraction (28.3% versus 29.5%; P <0.001) and longitudinal strain in all myocardial walls compared with patients without VT/VF (anterior-strain, −7.7% versus −8.8%; P <0.001; lateral-strain, −7.3% versus −7.9%; P =0.022; inferior-strain, −8.3% versus −9.9%; P <0.001; septal-strain, −9.1% versus −10.0%; P <0.001). After multivariate adjustment, only anterior and inferior longitudinal strain remained independent predictors of VT/VF (anterior: hazard ratio, 1.08 [1.03–1.13]; P =0.001; inferior: hazard ratio, 1.08 [1.04–1.12]; P <0.001; per 1% absolute decrease for both). When including B-type natriuretic peptide in the model, only a decreasing myocardial function in the inferior myocardial wall predicted VT/VF (hazard ratio, 1.05 [1.00–1.11]; P =0.039). Only strain obtained from the inferior myocardial wall provided incremental prognostic information for VT/VF over clinical and echocardiographic parameters (C statistic 0.71 versus 0.69; P =0.005).

Conclusions—

Assessment of regional longitudinal myocardial deformation in the inferior region provided incremental prognostic information over clinical and echocardiographic risk factors in predicting ventricular tachyarrhythmias.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00180271.

Regional Longitudinal Myocardial Deformation Provides Incremental Prognostic Information in Patients with ST-Segment Elevation Myocardial Infarction

Background

Global longitudinal systolic strain (GLS) has recently been demonstrated to be a superior prognosticator to conventional echocardiographic measures in patients after myocardial infarction (MI). The aim of this study was to evaluate the prognostic value of regional longitudinal myocardial deformation in comparison to GLS, conventional echocardiography and clinical information.

Method

In total 391 patients were admitted with ST-Segment elevation myocardial infarction (STEMI), treated with primary percutaneous coronary intervention and subsequently examined by echocardiography. All patients were examined by tissue Doppler imaging (TDI) and two-dimensional strain echocardiography (2DSE).

Results

During a median-follow-up of 5.3 (IQR 2.5–6.1) years the primary endpoint (death, heart failure or a new MI) was reached by 145 (38.9%) patients. After adjustment for significant confounders (including conventional echocardiographic parameters) and culprit lesion, reduced longitudinal performance in the anterior septal and inferior myocardial regions (but not GLS) remained independent predictors of the combined outcome. Furthermore, inferior myocardial longitudinal deformation provided incremental prognostic information to clinical and conventional echocardiographic information (Harrell's c-statistics: 0.63 vs. 0.67, p = 0.032). In addition, impaired longitudinal deformation outside the culprit lesion perfusion region was significantly associated with an adverse outcome (p<0.05 for all deformation parameters).

Conclusion

Regional longitudinal myocardial deformation measures, regardless if determined by TDI or 2DSE, are superior prognosticators to GLS. In addition, impaired longitudinal deformation in the inferior myocardial segment provides prognostic information over and above clinical and conventional echocardiographic risk factors. Furthermore, impaired longitudinal deformation outside the culprit lesion perfusion region seems to be a paramount marker of adverse outcome.