The relationship between coronary artery calcium and layer-specific global longitudinal strain in patients with suspected coronary artery disease.

PURPOSE: Layer-specific global longitudinal strain (GLS) may provide important insights in patients with suspected coronary artery disease (CAD). We aimed to investigate the association between layer-specific GLS and coronary artery calcium score (CACS) in patients suspected of CAD. METHODS: We performed a retrospective study of patients suspected of CAD who underwent both an echocardiogram and cardiac computed tomography (median 42 days between). Layer-specific (endocardial-, whole-layer-, and epicardial-) GLS was measured using speckle tracking echocardiography. We assessed the continuous association between layer-specific GLS and CACS by negative binomial regression, and the association with high CACS (≥400) using logistic regression. RESULTS: Of the 496 patients included (mean age 59 years, 56% male), 64 (13%) had a high CACS. Those with high CACS had reduced GLS in all layers compared to those with CACS < 400 (endocardial GLS: -20.5 vs. -22.7%, whole-layer GLS: -17.7 vs. -19.4%, epicardial GLS: -15.3 vs. -16.9%, p < .001 for all). Negative binomial regression revealed a significant continuous association showing increasing CACS with worsening GLS in all layers, which remained significant after multivariable adjustment including SCORE chart risk factors. All layers of GLS were associated with high CACS in univariable analyses, which was consistent after multivariable adjustment (endocardial GLS: OR = 1.11 (1.03-1.20); whole-layer GLS: OR = 1.14 (1.04-1.24); epicardial GLS: OR = 1.16 (1.05-1.29), per 1% absolute decrease). CONCLUSION: In this study population with patients suspected of CAD and normal systolic function, impaired layer-specific GLS was continuously associated with increasing CACS, and decreasing GLS in all layers were associated with presence of high CACS.

Parameters associated with improvement of systolic function in patients with heart failure.

AIMS: Identifying clinical and echocardiographic parameters associated with improvement in systolic function in outpatients with heart failure with reduced ejection fraction (HFrEF) could lead to more targeted treatment improving systolic function and outcome. METHODS: In a retrospective cohort study, echocardiographic examinations from the first and final visit of 686 patients with HFrEF at the heart failure clinic at Gentofte Hospital were retrieved and analysed. Parameters associated with left ventricular ejection fraction (LVEF) improvement and survival according to LVEF improvement were assessed using linear regression and Cox regression, respectively. Beta-coefficients (ß-coef) are standardised. Strain values are absolute. RESULTS: While undergoing heart failure treatment, 559 (81.5%) patients improved systolic function ( Δ LVEF >0%), with 100 (14.6%) being super responders defined by LVEF improvement >20%. After multivariable adjustment, LVEF improvement was significantly associated with a less impaired global longitudinal strain (ß-coef 0.25, p<0.001), higher tricuspid annular plane systolic excursion (ß-coef 0.09, p=0.018), smaller left ventricular internal dimension in diastole (ß-coef -0.15, p=0.011), lower E-wave/A-wave ratio (ß-coef -0.13, p=0.003), higher heart rate (ß-coef 0.18, p<0.001) and absence of ischaemic cardiomyopathy (ß-coef -0.11, p=0.010) and diabetes (ß-coef -0.081, p=0.033) at baseline. Mortality incidence rates differed with LVEF improvement ( Δ LVEF <0% vs Δ LVEF >0%, 8.3 vs 4.3 per 100 person years, p=0.012). Greater improvement in LVEF was associated with significantly lower mortality risk (tertile 1 vs tertile 3, HR 3.23, 95% CI 1.39 to 7.51, p=0.006). CONCLUSION: In this outpatient HFrEF cohort, most patients improved systolic function. Heart failure aetiology, comorbidities and echocardiographic measures of heart structure and function were significantly, independently associated with future LVEF improvement. Greater LVEF improvement was significantly associated with lower mortality.

Left atrial functional measurements' utility in predicting long-term risk of atrial fibrillation after isolated CABG.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia following coronary artery bypass grafting (CABG). We hypothesized that measures of left atrial (LA) function would be useful in predicting AF in patients undergoing CABG. METHODS AND RESULTS: In the study, 611 patients were included after CABG. All patients had echocardiograms performed preoperatively and LA functional measurements were assessed. These measurements were LA maximum volume index (LAVmax), LA minimum volume index (LAVmin) and LA emptying fraction (LAEF). The endpoint was AF occurring >14 days after surgery. During the follow-up period of a median of 3.7 years, 52 (9%) developed AF. The mean age was 67 years, 84% were male and the average left ventricle ejection fraction was 50%. Patients who developed AF had a lower CCS class and lower LAEF (40 vs. 45%), otherwise no clinical differences were observed between outcome groups. No functional LA measurements were significant predictors of AF in the whole CABG population. However, in patients with normal-sized LA (n = 532, events: 49), both LAEF and LAVmin were univariable predictors of AF. When the functional measurements were adjusted for the CHADS2 score, both LAVmin (HR = 1.07 [1.01-1.13], p = .014) and LAEF (HR: 1.02 [1.00-1.03], p = .023), remained significant predictors. CONCLUSION: No echocardiographic measurements were significant predictors of AF after CABG. In patients with a normal LA size, LAVmin as well as LAEF were significant predictors of AF.

Left atrial reservoir strain predicts ischaemic stroke after coronary artery bypass grafting independent of postoperative atrial fibrillation.

Aims: Measures of left atrial (LA) function are known to predict both ischaemic stroke and atrial fibrillation in specific patient groups. The aim of this study was to investigate the value of LA reservoir strain for predicting ischaemic stroke in patients undergoing coronary artery bypass grafting (CABG) and investigate whether the presence of postoperative atrial fibrillation (POAF) modified this relationship. Methods and results: Patients undergoing isolated CABG were included. The primary endpoint was ischaemic stroke. The association between LA reservoir strain and ischaemic stroke was investigated in uni- and multivariable Cox proportional hazards regression models including adjustment for POAF.We included 542 patients (mean age 67.3±8.9 years, 16.4% female). During a median follow-up period of 3.9 years, 21 patients (3.9%) experienced an ischaemic stroke. In total, 96 patients (17.7%) developed POAF during the index hospitalization. In a multivariable-adjusted Cox proportional hazards regression model, LA reservoir strain was significantly associated with the development of ischaemic stroke [HR (hazard ratio) 1.09 (95% CI 1.02-1.17) per 1% decrease, P = 0.011]. The presence of POAF did not modify this association (p for interaction = 0.07). The predictive value of the LA reservoir strain persisted in multiple sensitivity analyses including restricting the analysis to patients with normal left atrial volumes (LAV<34 ml/m2), patients without POAF, patients without prior stroke, and when excluding patients who developed atrial fibrillation at any time during follow-up. Conclusion: LA reservoir strain was independently associated with ischaemic stroke in CABG patients. The predictive value of LA reservoir strain was unaffected by the presence of POAF. Prospective studies are warranted to validate the potential usefulness of LA reservoir strain to predict postoperative ischaemic stroke in the setting of CABG.

Right ventricular strain predicts adverse outcomes in patients undergoing coronary artery bypass grafting.

Patients undergoing coronary artery bypass grafting (CABG) face an elevated risk of heart failure (HF) and cardiovascular (CV) death. Detailed myocardial tissue analyses of the right ventricle are now possible and may hold prognostic value in these patients. Accordingly, we aimed to evaluate the usefulness of right ventricular (RV) layer-specific RV free wall strain (RVFWS) for predicting HF and/or CV death. Patients undergoing CABG at Gentofte Hospital from 2006 to 2011 with a preoperative echocardiogram underwent RVWFS analysis. RVFWS was obtained by speckle tracking. The outcome was defined as a composite of HF and/or CV death. Cox proportional hazards regression, Harrell's C-statistics, and competing risk regression were used to assess the prognostic value of RVFWS. Of 317 patients, 30 (9.5%) reached the endpoint at a median follow-up of 3.5 years. The mean age was 67 years, 83% were men, and the mean LVEF was 50%. In univariable analyses, endo-RVFWS (HR 1.08, P < 0.001), mid-RVFWS (HR 1.07, P = 0.002), and epi-RVFWS (HR 1.07, P = 0.004, per 1% absolute decrease) were associated with a higher risk of HF or/and CV death. Furthermore, all three layers remained independently associated with the outcome after multivariable adjustment for baseline clinical and echocardiographic measurements. Low endo-RVFWS was associated with a more than threefold increased risk of the outcome (HR = 3.04 (1.45-6.38) P = 0.003). The same was observed for mid-RVFWS (HR = 3.16 (1.45-6.91) P = 0.004), and epi-RVFWS (HR = 3.00 (1.46-6.17) P = 0.003). In patients undergoing CABG, RVFWS assessed by speckle-tracking is a predictor of adverse outcomes.

Layer-specific and whole wall global longitudinal strain predict major adverse cardiovascular events in patients with stable angina pectoris.

Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of layer-specific GLS has not yet been investigated in patients with suspected stable angina pectoris (SAP). We sought to investigate the prognostic value of layer-specific and whole wall GLS in patients with suspected SAP. From September 2008 to March 2011, 296 consecutive patients with clinically suspected SAP, normal ejection fraction, and no previous cardiac history were enrolled in a prospective cohort study. Patients underwent echocardiography including two-dimensional speckle tracking at rest, exercise stress test, and coronary angiography. The end-point was a composite of incident heart failure, acute myocardial infarction, and cardiovascular death (MACE). Out of the 285 included patients (mean age 61 years, 50% male), 24 (8%) developed MACE during a median follow-up of 3.5 years. Both endocardial [hazard ratio (HR) 1.21, 95% CI 1.08-1.35, p = 0.001], epicardial (HR 1.29, 95% CI 1.12-1.50, p = 0.001) and whole wall GLS (HR 1.25, 1.10-1.42, p = 0.001) were significantly associated with an increased risk of developing MACE during follow-up in univariable Cox regression analysis. In multivariable analysis, only epicardial (HR 1.23, 95% CI 1.00-1.51, p = 0.046) and whole wall GLS (HR 1.20, 95% CI 1.00-1.43, p = 0.049) remained significantly associated with an increased risk of MACE independent of various baseline clinical variables, left ventricular ejection fraction (LVEF), E/e' and Duke Score. Layer-specific and whole wall GLS were significant predictors of MACE in this cohort of patients with suspected SAP independent of various baseline clinical variables, LVEF, E/e' and Duke Score.

Longitudinal change in cardiac structure and function following acute coronary syndrome according to culprit coronary artery lesion.

Acute coronary syndrome (ACS) may lead to adverse remodelling and impaired cardiac function. Limited data exists on the effect of culprit coronary artery lesion site and impact on longitudinal cardiac remodelling. The present study included a total of 299 patients suffering from ACS treated with percutaneous coronary intervention (PCI). All patients had two echocardiographic examinations. The first echocardiography was median 2(IQR: 1;3) days following PCI, while the follow-up echocardiography (FUE) was median 257(IQR: 96;942) days following the first. Patients were grouped based on coronary artery PCI location; left anterior descending artery (LAD), right coronary artery (RCA) or circumflex artery (Cx). Patients with multiple lesions were excluded. Mean age was 63 ± 11 years and 77% were male. At FUE, mean left ventricular ejection fraction was 42 ± 9% and global longitudinal strain (GLS) was - 13 ± 4%. PCI treatment was allocated as 168 LAD lesions, 95 RCA lesions, and 36 Cx lesions. Linear regression analysis showed that patients with a LAD lesion displayed worsening in E/A (mean ∆ = 0.05, ß = - 0.196, p = 0.001) and a larger increase in LVEDV (mean ∆ = 33.18 mL, ß = 0.135, p = 0.012). Meanwhile patients with Cx lesion were significantly associated with a larger decrease in E/e' (mean ∆ = 2.6, ß = - 0.120, p = 0.028). Patients with Cx lesion were observed to have elevated E/e' at baseline, which normalized at FUE. The present study suggests that culprit coronary artery lesion has a differential impact on myocardial remodelling. This information may potentially aid in understanding the pathophysiological differences in cardiac structure and function amongst patients with ACS.

Early diastolic strain rate in relation to long term prognosis following isolated coronary artery bypass grafting.

BACKGROUND: The ratio of early mitral inflow velocity to early diastolic strain rate (E/e'sr) is a novel echocardiographic measure to estimate early left ventricular (LV) filling pressure. We hypothesize that E/e'sr is a predictor of outcome following coronary artery bypass grafting (CABG) and that it is superior to the conventionally used E/e'. METHODS & RESULTS: Consecutive patients undergoing isolated CABG at Gentofte Hospital (n = 652) were included. The mean age of the study population was 67 ± 9 years, 84% were male, mean LVEF was 50 ± 11%. Prior to surgery, all patients underwent an extensive echocardiographic examination. The outcome was all-cause mortality. During follow-up (median 3.8 years [IQR: 2.7; 4.9 years]), a total of 73 (11.2%) died. Both E/e' and E/e'sr were significant predictors in univariable models. In a multivariable model, E/e'sr remained an independent predictor of outcome (HR:1.05 [1.01-1.10], p = 0.049, per 10 cm increase) whereas E/e' did not (HR:1.05 [0.99-1.11], p = 0.053, per 1-unit increase). The relationship between E/e'sr, and the outcome was significantly modified by GLS (p for interaction = 0.043). In the multivariable model, E/e'sr was still significantly associated with the outcome in patients with high GLS (≥13.6%) (HR:1.18 [1.02-1.36], p = 0.029) but not in patients with low GLS (HR 1.04 CI95%: [0.99-1.10], p = 0.14). E/e' was not a significant predictor of all-cause mortality after multivariable adjustment in neither of the groups. E/e'sr improved net reclassification with 33% when added to EuroSCOREII. CONCLUSION: Following CABG, preoperative E/e'sr is an independent predictor of all-cause mortality, especially in patients with preserved systolic function and superior to E/e'.

Prognostic value of right ventricular echocardiographic measures in patients with heart failure with reduced ejection fraction.

PURPOSE: Right ventricular (RV) dysfunction is associated with poor outcome in patients with heart failure. In order to better predict mortality in this patient group we wanted to compare the prognostic value of conventional and advanced RV echocardiographic measures. METHODS: Echocardiographic examinations were retrieved from 701 patients. End point was all-cause mortality and follow-up 100%. RV parameters were measured offline in accordance with current guidelines. Speckle tracking was derived using the algorithm originally designed for the left ventricle. RESULTS: During follow-up (median: 39 months) 118 patients (16.8%) died. RV global longitudinal strain (GLS) and RV free wall strain (FWS) remained associated with mortality after multivariable adjustment independent of Tricuspid annular plane systolic excursion (TAPSE) (RV GLS: HR 1.07, 95%CI 1.02-1.13, p = 0.010, per 1% decrease) (RV FWS: HR 1.05, 95%CI 1.01-1.09, p = 0.010, per 1% decrease). This seemed to be caused by significant associations in men. All RV estimates provided prognostic information incremental to established risk factors and significantly increased C-statistics. CONCLUSIONS: RV GLS and FWS were associated with mortality in HFrEF patients after multivariable adjustment independent of TAPSE. TAPSE, however, remained as the strongest prognosticator in women. More research is needed to identify whether speckle tracking could be superior to conventional RV measures in identifying HFrEF patients with poor outcome.

Early systolic lengthening by speckle tracking echocardiography predicts outcome after coronary artery bypass surgery.

BACKGROUND: Early systolic lengthening (ESL), a paradoxical stretch of myocardial fibers, has been linked to loss of myocardial viability and contractile dysfunction. We assessed the long-term prognostic potential of ESL in coronary artery bypass graft (CABG) patients. METHODS: We retrospectively included patients (n = 709; mean age 68 years; 85% men) who underwent speckle tracking echocardiography (median 15 days) prior to CABG. Endpoints were cardiovascular death (CVD) and all-cause mortality. We assessed amplitude of ESL (%), defined as peak positive strain, and duration of ESL (ms), determined as time from Q-wave on the ECG to peak positive strain. We applied Cox models adjusted for clinical risk assessed as EuroSCORE II. RESULTS: During median follow-up of 3.8 years [IQR 2.7-4.9 years], 45 (6%) experienced CVD and 80 (11%) died. In survival analyses adjusted for EuroSCORE II, each 1% increase in amplitude of ESL was associated with CVD (HR 1.35 [95%CI 1.09-1.68], P = 0.006) and all-cause mortality (HR 1.29 [95%CI 1.08-1.54], P = 0.004). Similar findings applied to duration of ESL (per 10ms increase) and CVD (HR 1.12 [95%CI 1.02-1.23], P = 0.016) and all-cause mortality (HR 1.09 [95%CI 1.01--1.17], P = 0.031). The prognostic value of ESL amplitude was modified by sex (P interaction < 0.05), such that the prognostic value was greater in women for both endpoints. When adding ESL duration to EuroSCORE II, the net reclassification index improved significantly for both CVD and all-cause mortality. CONCLUSIONS: Assessment of ESL provides independent and incremental prognostic information in addition to the EuroSCORE II for CVD and all-cause mortality in CABG patients.

Change in global longitudinal strain following acute coronary syndrome and subsequent risk of heart failure.

Global Longitudinal Strain (GLS) is a well-established predictor of heart failure (HF) following acute coronary syndrome (ACS). We aim to investigate the prognostic value of GLS obtained at a follow-up consultation, as well as the change in GLS for long-term risk of incident HF. A total of 235 ACS patients had an echocardiogram performed immediately after percutaneous coronary intervention (PCI) and a follow-up echocardiogram (FUE) median 215 (IQR: 71; 878) days after the first echocardiogram. Endpoint was incident HF. Follow-up time after FUE was median 4.8 (IQR: 3.7; 5.6) years. Patients diagnosed with HF before FUE were excluded. Mean age was 63 ± 11 years and 77% were male. Baseline GLS was on average 12.7 ± 3.9%, FUE GLS was on average 13.5 ± 3.9% and mean improvement in GLS was 0.73 ± 3.68% between the 2 echocardiograms. A total of 57 (24%) patients suffered incident HF following the FUE. FUE GLS provided significantly higher prognostic information for risk of incident HF than ∆GLS when assessed by the C-statistics (C-statistics: 0.71 vs. 0.61, P = 0.021). Furthermore, after multivariable adjustments only FUE GLS [HR = 1.15, 95% CI (1.02; 1.29), P = 0.018, per 1% decrease] remained an independent predictor of incident HF. In patients with ACS, who do not develop HF before FUE, FUE GLS was an independent predictor of long-term risk of incident HF while ∆GLS was not.

The prognostic value of myocardial deformational patterns on all-cause mortality is modified by ischemic cardiomyopathy in patients with heart failure.

Early systolic lengthening and postsystolic shortening may yield prognostic information in cardiovascular high-risk groups. We aimed to investigate the prognostic potential of these patterns in patients with heart failure with reduced ejection fraction (HFrEF), and specifically if the value was greater in patients with ischemic etiology. A total of 884 patients with HFrEF (66 ± 12 years, male 73%, mean EF 28 ± 9%) underwent speckle tracking echocardiography. Of these, 61% suffered from ischemic cardiomyopathy (ICM). Patients were followed for all-cause mortality. We assessed myocardial lengthening during early systole, defined by the early systolic strain index (ESI): [-100x (peak positive strain/maximal strain)] and myocardial shortening after aortic valve closure, defined by the postsystolic strain index (PSI): [100x (postsystolic strain-peak systolic strain)/maximal strain]. During median follow-up of 3.4 [interquartile range 1.9 to 4.8] years, 132 patients (15%) died. ICM modified the relationship between ESI and all-cause mortality (P interaction = 0.008), but not for PSI (P interaction = 0.13). When assessing patients with ICM by Cox proportional hazards models, per 1% increase in ESI (HR 1.09 [1.04 to 1.15], P < 0.001) and PSI (HR 1.02 [1.01 to 1.03], P = 0.002) were associated with all-cause mortality. However, in multivariable models adjusted for clinical, invasive and echocardiographic information, only ESI was a predictor of the endpoint (HR 1.07 [1.00 to 1.13], P = 0.023). In patients with no ICM, neither ESI (HR 0.99 per 1% increase [0.90 to 1.09], P = 0.86) nor PSI (HR 1.00 per 1% increase [0.99 to 1.02], P = 0.88) were associated with all-cause mortality. Our results indicate that in HFrEF patients with ischemic etiology, the ESI may provide some information on prognosis, whereas the prognostic value of PSI is reduced. In patients with HFrEF and no prior exposure to ischemia, the prognostic value of both deformational patterns is reduced.

Prognostic and comparative performance of cardiovascular risk markers in patients with type 2 diabetes.

BACKGROUND: Diagnostic tests including echocardiography, albuminuria, electrocardiogram (ECG), high-sensitivity troponin I (hs-TnI), and N-terminal prohormone brain natriuretic peptide (NT-proBNP) have been suggested as cardiovascular (CV) risk predictors in type 2 diabetes. We studied the separate and combined prognostic yield of these risk markers. METHODS: In all, 1030 patients with type 2 diabetes were recruited from specialized clinics in this prospective cohort study. Full echocardiographic evaluation was feasible in 886 patients in sinus rhythm with adequate image quality. ECG was performed in 998 patients. Albuminuria was measured in 1009 and NT-proBNP/hs-TnI in 933 patients. The end point was a composite of CV events. RESULTS: The median follow-up was 4.7 years (interquartile range: 4.0-5.3), and 174 patients experienced a CV disease event. All considered markers, except hs-TnI, were significantly (P < .001) associated with the outcome: abnormal echocardiogram (hazard ratio 2.40 [1.70-3.39]), albuminuria 2.01 (1.47-2.76), abnormal ECG (2.27 [1.66-3.08]), high NT-proBNP (>150 pg/mL) 3.05 (2.11-4.40), and hs-TnI 1.12 (0.79-1.59). After adjusting for clinical variables, all remained significantly associated with the end point. However, after adjusting for each other, only NT-proBNP >150 pg/mL remained significantly associated with the end point (2.07 [1.28-3.34], P < .001). Measured by C-statistics, model performance was highest with log2 (NT-proBNP) (0.70 [0.65-0.75]) and similar to clinical variables alone (0.71 [0.67-0.76]). Combining all risk markers only resulted in a very limited increase in C-statistics (0.69 [0.64-0.74]). CONCLUSIONS: This study identified NT-proBNP over echocardiography, ECG, and albuminuria in risk prediction in patients with type 2 diabetes. The diagnostic yield in considering more than one risk marker was limited in this population.

Prognostic Value of Coronary CT Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndromes.

BACKGROUND: Severity and extent of coronary artery disease (CAD) assessed by invasive coronary angiography (ICA) guide treatment and may predict clinical outcome in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). OBJECTIVES: This study tested the hypothesis that coronary computed tomography angiography (CTA) is equivalent to ICA for risk assessment in patients with NSTEACS. METHODS: The VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes) trial evaluated timing of treatment in relation to outcome in patients with NSTEACS and included a clinically blinded coronary CTA conducted prior to ICA. Severity of CAD was defined as obstructive (coronary stenosis ≥50%) or nonobstructive. Extent of CAD was defined as high risk (obstructive left main or proximal left anterior descending artery stenosis and/or multivessel disease) or non-high risk. The primary endpoint was a composite of all-cause death, nonfatal recurrent myocardial infarction, hospital admission for refractory myocardial ischemia, or heart failure. RESULTS: Coronary CTA and ICA were conducted in 978 patients. During a median follow-up time of 4.2 years (interquartile range: 2.7 to 5.5 years), the primary endpoint occurred in 208 patients (21.3%). The rate of the primary endpoint was up to 1.7-fold higher in patients with obstructive CAD compared with in patients with nonobstructive CAD as defined by coronary CTA (hazard ratio [HR]: 1.74; 95% confidence interval [CI]: 1.22 to 2.49; p = 0.002) or ICA (HR: 1.54; 95% CI: 1.13 to 2.11; p = 0.007). In patients with high-risk CAD, the rate of the primary endpoint was 1.5-fold higher compared with the rate in those with non-high-risk CAD as defined by coronary CTA (HR: 1.56; 95% CI: 1.18 to 2.07; p = 0.002). A similar trend was noted for ICA (HR: 1.28; 95% CI: 0.98 to 1.69; p = 0.07). CONCLUSIONS: Coronary CTA is equivalent to ICA for the assessment of long-term risk in patients with NSTEACS. (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes [VERDICT]; NCT02061891).

Global longitudinal strain predicts cardiovascular events after coronary artery bypass grafting.

OBJECTIVE: To determine the prognostic value of global longitudinal strain (GLS) after coronary artery bypass grafting (CABG). METHODS: We performed a retrospective cohort study on patients undergoing CABG between 2006 and 2011 who had an echocardiogram available for strain analysis. The patients were followed up through nationwide registries for development of all-cause mortality, cardiovascular death (CVD) and major adverse cardiovascular events (MACEs) defined as heart failure hospitalisation and/or CVD. Multivariable Cox regression was applied to adjust for the European System for Cardiac Operative Risk Evaluation II (EuroSCORE-II). Additive value was assessed by Net Reclassification Index (NRI) improvement. RESULTS: Of the 709 patients included, 80 died during a median follow-up of 3.8 years. Of these, 45 had CVD, and 72 patients experienced MACE. Mean age was 68 years and 85% were men. Left ventricular ejection fraction (LVEF) was 50% and GLS was -13%.GLS was an independent predictor when adjusted for the EuroSCORE-II (all-cause mortality: HR=1.07 (1.01-1.13), p=0.018; CVD: HR=1.11 (1.03-1.20), p=0.007; MACE: HR=1.12 (1.06-1.19), p<0.001, per 1% absolute decrease). GLS significantly improved the NRI score by 0.30 when added to the EuroSCORE-II for predicting MACE, but not significantly for the other endpoints.LVEF modified the association between GLS and outcomes (p for interaction<0.05 for CVD and MACE). GLS remained an independent predictor of outcomes in patients with preserved LVEF (LVEF≥50%) and improved the NRI score when added to the EuroSCORE-II for predicting CVD and MACE, but not all-cause mortality in these patients. CONCLUSION: GLS is an independent predictor of long-term outcomes after CABG. The predictive value appears strongest among patients with preserved LVEF.

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.

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.

Prognostic Value of Early Systolic Lengthening by Strain Imaging in Type 2 Diabetes.

BACKGROUND: Patients with type 2 diabetes (T2D) have increased risk for subclinical myocardial disease. Early systolic lengthening (ESL), a paradoxical stretch of myocardial fibers, is a sensitive marker of myocardial dysfunction. The aims of this study were to investigate the prognostic value of ESL in patients with T2D and to determine if global longitudinal strain (GLS) modifies this relationship. METHODS: In this prospective study, speckle-tracking echocardiography was conducted in 703 patients with T2D (62% men; mean age, 63 ± 10 years; median diabetes duration, 11 years; interquartile range, 6-17 years). Patients had no histories of significant heart disease. ESL index was assessed as [-100 × (peak positive systolic strain/maximal strain)] and ESL duration as time from QRS complex on the electrocardiogram to time of peak positive systolic strain. P values ≤ .004 were considered to indicate statistical significance. RESULTS: During a median follow-up time of 4.8 years (interquartile range, 4.1-5.3 years), 86 patients (12%) experienced major adverse cardiovascular events (MACE), a composite of incident heart failure, myocardial infarction, and cardiovascular death. In multivariate models, only the ESL index (hazard ratio [HR], 1.06 per 1% increase; 95% CI, 1.01-1.010; P = .004) but not ESL duration (HR, 1.02 per 1-ms increase; 95% CI, 1.00-1.03; P = .036) were associated with MACE. GLS modified this relationship (P for interaction < .05) such that in patients with low GLS (>-18%), ESL index (HR, 1.06 per 1% increase; 95% CI, 1.02-1.10; P = .003) was associated with MACE, but ESL duration was not (HR, 1.02 per 1-ms increase; 95% CI, 1.00-1.04; P = .005). No associations were found for high GLS (<-18%). CONCLUSIONS: In patients with T2D and no histories of heart disease, ESL provides prognostic information on MACE and may potentially aid in cardiovascular risk stratification.

Association between the E-wave propagation index and left ventricular thrombus formation after ST-elevation myocardial infarction.

OBJECTIVE: To explore the association between E-wave propagation index (EPI) as a marker of apical washout and the risk of left ventricular thrombus (LVT) formation in patients with ST-elevation myocardial infarction (STEMI). METHODS: We performed a post-hoc analysis on 364 prospectively enrolled STEMI patients from a single-center. Non-contrast transthoracic echocardiographic examinations were performed a median of 2 days (IQR:1-3 days) after PCI. The endpoint was LVT formation, identified retrospectively. Univariable and multivariable logistic regression was applied to assess the association between EPI and LVT formation. Multivariable adjustments included LVEF, LAD culprit, prior myocardial infarction, heart rate, and early myocardial relaxation velocity. Area under receiver operating characteristic curves (AUC) was used to assess the diagnostic ability. RESULTS AND CONCLUSIONS: Among 364 patients, 31 (8.5%) developed LVT. The mean age was 62 years, 75% were men, and mean LVEF was 46%. Patients developing LVT had increased heart rate, lower LVEF, impaired GLS, and more frequently had prior myocardial infarction. Variables associated with low values of EPI included, among others, LVEF, LV aneurysm, and GLS. EPI and LVT formation were significantly associated in the univariable model (OR = 1.87 (1.53-2.28), p < 0.001), and EPI showed an AUC of 0.90. After multivariable adjustments, EPI and LVT formation remained significantly associated (OR = 1.79 (1.42-2.27), p < 0.001). Patients with an EPI < 1.0 had a 23 times higher likelihood of LVT formation (OR = 23.41 (10.06-54.49), p < 0.001). EPI and LVT formation are strongly associated in patients with STEMI, with low values of EPI indicating a markedly increased probability of LVT formation.