Objectives This study sought to test the hypothesis that semiautomated calculation of left ventricular global longitudinal strain (GLS) can identify high-risk subjects among patients with myocardial ...infarctions (MIs) with left ventricular ejection fractions (LVEFs) >40%. Background LVEF is a key determinant in decision making after acute MI, yet it is relatively indiscriminant within the normal range. Novel echocardiographic deformation parameters may be of particular clinical relevance in patients with relatively preserved LVEFs. Methods Patients with MIs and LVEFs >40% within 48 h of admission for coronary angiography were prospectively included. All patients underwent echocardiography with semiautomated measurement of GLS. The primary composite endpoint (all-cause mortality and hospitalization for heart failure) was analyzed using Cox regression analyses. The secondary endpoints were cardiac death and heart failure hospitalization. Results A total of 849 patients (mean age 61.9 ± 12.0 years, 73% men) were included, and 57 (6.7%) reached the primary endpoint (median follow-up 30 months). Significant prognostic value was found for GLS (hazard ratio HR: 1.20; 95% confidence interval CI: 1.10 to 1.32; p < 0.001). GLS > −14% was associated with a 3-fold increase in risk for the combined endpoint (HR: 3.21; 95% CI: 1.82 to 5.67; p < 0.001). After adjustment for other variables, GLS remained independently related to the combined endpoint (HR: 1.14; 95% CI: 1.04 to 1.26; p = 0.007). For the secondary endpoints, GLS > −14% was significantly associated with cardiovascular death (HR: 12.7; 95% CI: 3.0 to 54.6; p < 0.001) and heart failure hospitalization (HR: 5.31; 95% CI: 1.50 to 18.82; p < 0.001). Conclusions Assessment of GLS using a semiautomated algorithm provides important prognostic information in patients with LVEFs >40% above and beyond traditional indexes of high-risk MI.
Objectives This study sought to hypothesize that global longitudinal strain (GLS) as a measure of infarct size, and mechanical dispersion (MD) as a measure of myocardial deformation heterogeneity, ...would be of incremental importance for the prediction of sudden cardiac death (SCD) or malignant ventricular arrhythmias (VA) after acute myocardial infarction (MI). Background SCD after acute MI is a rare but potentially preventable late complication predominantly caused by malignant VA. Novel echocardiographic parameters such as GLS and MD have previously been shown to identify patients with chronic ischemic heart failure at increased risk for arrhythmic events. Risk prediction during admission for acute MI is important because a majority of SCD events occur in the early period after hospital discharge. Methods We prospectively included patients with acute MI and performed echocardiography, with measurements of GLS and MD defined as the standard deviation of time to peak negative strain in all myocardial segments. The primary composite endpoint (SCD, admission with VA, or appropriate therapy from a primary prophylactic implantable cardioverter-defibrillator ICD) was analyzed with Cox models. Results A total of 988 patients (mean age: 62.6 ± 12.1 years; 72% male) were included, of whom 34 (3.4%) experienced the primary composite outcome (median follow-up: 29.7 months). GLS (hazard ratio HR: 1.38; 95% confidence interval CI: 1.25 to 1.53; p < 0.0001) and MD (HR/10 ms: 1.38; 95% CI: 1.24 to 1.55; p < 0.0001) were significantly related to the primary endpoint. GLS (HR: 1.24; 95% CI: 1.10 to 1.40; p = 0.0004) and MD (HR/10 ms: 1.15; 95% CI: 1.01 to 1.31; p = 0.0320) remained independently prognostic after multivariate adjustment. Integrated diagnostic improvement (IDI) and net reclassification index (NRI) were significant for the addition of GLS (IDI: 4.4% p < 0.05; NRI: 29.6% p < 0.05), whereas MD did not improve risk reclassification when GLS was known. Conclusions Both GLS and MD were significantly and independently related to SCD/VA in these patients with acute MI and, in particular, GLS improved risk stratification above and beyond existing risk factors.
Objectives The aim of this study was to test the hypothesis that strain echocardiography might improve arrhythmic risk stratification in patients after myocardial infarction (MI). Background ...Prediction of ventricular arrhythmias after MI is challenging. Left ventricular ejection fraction (LVEF) <35% is the main parameter for selecting patients for implantable cardioverter-defibrillator therapy. Methods In this prospective, multicenter study, 569 patients >40 days after acute MI were included, 268 of whom had ST-segment elevation MIs and 301 non–ST-segment elevation MIs. By echocardiography, global strain was assessed as average peak longitudinal systolic strain from 16 left ventricular segments. Time from the electrocardiographic R-wave to peak negative strain was assessed in each segment. Mechanical dispersion was defined as the standard deviation from these 16 time intervals, reflecting contraction heterogeneity. Results Ventricular arrhythmias, defined as sustained ventricular tachycardia or sudden death during a median 30 months (interquartile range: 18 months) of follow-up, occurred in 15 patients (3%). LVEFs were reduced (48 ± 17% vs. 55 ± 11%, p < 0.01), global strain was markedly reduced (−14.8 ± 4.7% vs. −18.2 ± 3.7%, p = 0.001), and mechanical dispersion was increased (63 ± 25 ms vs. 42 ± 17 ms, p < 0.001) in patients with arrhythmias compared with those without. Mechanical dispersion was an independent predictor of arrhythmic events (per 10-ms increase, hazard ratio: 1.7; 95% confidence interval: 1.2 to 2.5; p < 0.01). Mechanical dispersion and global strain were markers of arrhythmias in patients with non–ST-segment elevation MIs (p < 0.05 for both) and in those with LVEFs >35% (p < 0.05 for both), whereas LVEF was not (p = 0.33). A combination of mechanical dispersion and global strain showed the best positive predictive value for arrhythmic events (21%; 95% confidence interval: 6% to 46%). Conclusions Mechanical dispersion by strain echocardiography predicted arrhythmic events independently of LVEF in this prospective, multicenter study of patients after MI. A combination of mechanical dispersion and global strain may improve the selection of patients after MI for implantable cardioverter-defibrillator therapy, particularly in patients with LVEFs >35% who did not fulfill current implantable cardioverter-defibrillator indications.
Heart failure (HF) complicating acute myocardial infarction (MI) is an ominous prognostic sign frequently caused by left ventricular (LV) systolic dysfunction. However, many patients develop HF ...despite preserved LV ejection fractions. The aim of this study was to test the hypothesis that LV longitudinal function is a stronger marker of in-hospital HF than traditional echocardiographic indices.
A total of 548 patients with acute MIs were evaluated (mean age, 63.2 ± 11.7 years; 71.6% men). Within 48 hours of admission, comprehensive echocardiography with assessment of global longitudinal strain (GLS) was performed, along with measurements of N-terminal pro-brain natriuretic peptide.
A total 89 patients (16.2%) had in-hospital HF assessed by Killip class > 1 in whom GLS was significantly impaired compared with patients without in-hospital HF (Killip class 1) (-14.6 ± 3.3% vs -10.1 ± 3.5%, P < .0001). In stepwise multiple logistic regression analysis including age, known HF, three-vessel disease, involvement of the left anterior descending coronary artery, episodes of atrial fibrillation, renal function, N-terminal pro-brain natriuretic peptide, troponin T level, LV ejection fraction, wall motion score index, and diastolic dysfunction indices, GLS emerged as the strongest marker of clinical HF (odds ratio, 1.47; 95% confidence interval CI, 1.33-1.62; P < .0001). GLS remained independently associated with in-hospital HF in patients with LV ejection fractions > 40% (odds ratio, 1.33; 95% CI, 1.14-1.54; P < .05) and improved the C-statistic over other important covariates significantly (0.87 95% CI, 0.82-0.91 vs 0.82 95% CI, 0.76-0.89, P = .02).
Global longitudinal function assessed by GLS is significantly impaired in patients with MIs with in-hospital HF, and multivariate analysis suggests that reduced GLS is the single most powerful marker of manifest LV hemodynamic deterioration in the acute phase of MI.
Abstract Background Increased pulmonary capillary wedge pressure (PCWP) is an independent prognostic predictor after myocardial infarction (MI), but PCWP is difficult to assess noninvasively in ...subjects with preserved ejection fraction (EF). We hypothesized that biomarkers would provide information regarding PCWP at rest and during exercise in subjects with preserved EF after MI. Methods and Results Seventy-four subjects with EF >45% and recent MI underwent right heart catheterization at rest and during a symptom-limited semisupine cycle exercise test with simultaneous echocardiography. Plasma samples were collected at rest for assessment of midregional pro–A-type natriuretic peptide (MR-proANP), N-terminal pro–B-type natriuretic peptide (NT-proBNP), galectin-3 (Gal-3), copeptin, and midregional pro-adrenomedullin (MR-proADM). Plasma levels of MR-proANP and PCWP were associated at rest ( r = 0.33; P = .002) and peak exercise ( r = 0.35; P = .002) as well as with changes in PCWP ( r = 0.26; P = .03). Plasma levels of NT-proBNP and PCWP were weakly associated at rest ( r = 0.23; P = .03) and peak exercise ( r = 0.28; P = .02) but not with changes in PCWP ( r = 0.20; P = .09). In a multivariable analysis, plasma levels of MR-proANP remained associated with rest and exercise PCWP ( P < .01), whereas NT-proBNP did not. Plasma levels of Gal-3, copeptin, and MR-proADM were not associated with PCWP at rest or peak exercise. Conclusions In subjects recovering from an acute MI with preserved EF, plasma levels of natriuretic peptides, particularly MR-proANP, are associated with filling pressures at rest and during exercise.
Electrical cardioversion (ECV) is recommended for rhythm control in patients with atrial arrhythmia; yet, ECV use and outcomes in contemporary practice are unknown. We reviewed all nonemergent ECVs ...for atrial arrhythmias at a tertiary care center (2010 to 2013), stratifying patients by transesophageal echocardiography (TEE) use before ECV and comparing demographics, history, vitals, and laboratory studies. Outcomes included postprocedural success and complications and repeat cardioversion, rehospitalization, and death within 30 days. Overall, 1,017 patients underwent ECV, 760 (75%) for atrial fibrillation and 240 (24%) for atrial flutter; 633 underwent TEE before ECV and 384 did not. TEE recipients were more likely to be inpatients (74% vs 44%, p <0.001), have higher mean CHADS2 scores (2.6 vs 2.4, p = 0.03), and lower mean international normalized ratios (1.2 vs 2.1, p <0.001). Overall, 89 patients (8.8%) did not achieve sinus rhythm and 14 experienced procedural complications (1.4%). Within 30 days, 80 patients (7.9%) underwent repeat ECV, 113 (11%) were rehospitalized, and 14 (1.4%) died. Although ECV success was more common in patients who underwent TEE before ECV (77% vs 68%, p = 0.01), there were no differences in 30-day death or rehospitalization rates (11.1% vs 13.0%, p = 0.37). In multivariate analyses, higher pre-ECV heart rate was associated with increased rehospitalization or death (adjusted hazard ratio 1.15/10 beats/min, 95% confidence interval 1.07 to 1.24, p <0.001), whereas TEE use was associated with lower rates (adjusted hazard ratio 0.58, 95% confidence interval 0.39 to 0.86, p = 0.007). In conclusion, failures, complications, and rehospitalization after nonemergent ECV are common and associated more with patient condition than procedural characteristics. TEE use was associated with better clinical outcomes.
Background Renal dysfunction in patients with acute myocardial infarction (MI) is an important predictor of short- and long-term outcome. Cardiac abnormalities dominated by left ventricular (LV) ...hypertrophy are common in patients with chronic renal dysfunction. However, limited data exists on the association between LV systolic- and diastolic function assessed by comprehensive echocardiography and renal dysfunction in contemporary unselected patients with acute MI. Methods We prospectively included 1054 patients with acute MI (mean age 63 years, 73% male) and performed echocardiographic assessment of systolic and diastolic function within 48 hours of admission as well as estimated glomerular filtration rate (eGFR). Results Reduced eGFR was significantly associated with LV mass, LV ejection fraction, LV global strain (GLS) and E/e′ ratio. After multivariable adjustment, E/e′ ratio ( P = .0096) remained the only echocardiographic measure independently associated with decreasing eGFR. During follow-up a total of 113 patients (10.7%) patients experienced the composite endpoint of all-cause mortality or hospitalization for heart failure. An eGFR <60 mL/min per 1.73 m2 was significantly associated with outcome (HR, 1.71; 95% CI, 1.12-2.62; P = .0131) after adjustment for age, diabetes, hypertension, Killip class >1, multivessel disease and troponin. The prognostic impact of an eGFR <60 mL/min per 1.73 m2 was only modestly altered by addition of LV mass or E/e′ ratio whereas addition of LV ejection fraction or GLS attenuated its importance considerably. Conclusion Renal dysfunction in patients with acute MI is independently associated with echocardiographic evidence of increased LV filling pressure. However, the prognostic importance of renal dysfunction is attenuated to a greater degree by LV longitudinal systolic function.
Objectives The aim of this study was to investigate the association between resting myocardial function as assessed by tissue Doppler myocardial velocities and the propensity to develop mental ...stress–induced ischemia (MSIMI). Background Tissue Doppler myocardial velocities detect preclinical cardiac dysfunction and clinical outcomes in a range of conditions. However, little is known about the interrelationship between myocardial velocities and the propensity to develop MSIMI compared with exercise stress–induced myocardial ischemia. Methods Resting annular myocardial tissue Doppler velocities were obtained in 225 patients with known coronary heart disease who were subjected to both conventional exercise stress testing as well as a battery of 3 mental stress tests. Diastolic early (e′) and late (a′) as well as systolic (s′) velocities were obtained, and the eas index, an integrated measure of myocardial velocities, was calculated as e′/(a′ × s′). MSIMI was defined as: 1) the development or worsening of regional wall motion abnormality; 2) a reduction in left ventricular ejection fraction ≥ 8%; and/or 3) ischemic ST-segment changes during 1 or more of the 3 mental stress tests. Results A total of 98 of 225 patients (43.7%) exhibited MSIMI. Patients developing MSIMI had significantly lower s′ (7.0 ± 1.7 vs. 7.5 ± 1.2, p = 0.016) and a′ (8.9 ± 1.8 vs. 10.0 ± 1.9, p < 0.001) at baseline, whereas e′ did not differ (6.5 ± 1.7 vs. 6.5 ± 1.8, p = 0.85). Furthermore, the eas index was significantly higher (0.11 ± 0.04 vs. 0.09 ± 0.03, p < 0.0001). The eas index remained significantly associated with the propensity to develop MSIMI (odds ratio per 0.05-U increase: 1.85; 95% confidence interval: 1.21 to 2.82; p = 0.004) after adjustment for resting left ventricular ejection fraction, resting wall motion index score, sex, and social circumstances of living. There was no association between resting eas index and exercise stress–induced myocardial ischemia. Conclusions MSIMI but not exercise stress–induced myocardial ischemia is independently associated with resting abnormalities in myocardial systolic and late diastolic velocities as well as the integrated measure of the eas index in patients with known coronary artery disease. (Responses of Myocardial Ischemia to Escitalopram Treatment REMIT; NCT00574847 )
Abstract Background Elevated levels of N-terminal pro brain natriuretic peptide (NT-proBNP) are associated with adverse cardiovascular outcome after ST elevation myocardial infarction (STEMI). We ...hypothesized that decreasing acuteness-score (based on the electrocardiographic score by Anderson-Wilkins acuteness score of myocardial ischemia) is associated with increasing NT-proBNP levels and the impact of decreasing acuteness-score on NT-proBNP levels is substantial in STEMI patients with severe ischemia. Methods In 186 STEMI patients treated with primary percutaneous coronary intervention (pPCI), the severity of ischemia (according to Sclarovsky-Birnbaum severity grades of ischemia) and the acuteness-score were obtained from prehospital ECG. Patients were classified according to the presence of severe ischemia or non-severe ischemia and acute ischemia or non-acute ischemia. Plasma NT-proBNP (pmol/L) was obtained after pPCI within 24 hours of admission and was correlated with the acuteness-score. Results NT-proBNP levels were median (25th–75th interquartile) 112 (51–219) pmol/L in patients with non-severe ischemia (71.5%) and 145 (79–339) in patients with severe ischemia (28.5%) ( p = 0.074). NT-proBNP levels were highest in patients with severe and non-acute ischemia compared to those with severe and acute ischemia (182 (98–339) pmol/L vs 105 (28–324) pmol/L, p = 0.012). There was a negative correlation between acuteness-score and log(NT-proBNP) in patients with severe ischemia (r = 0.395, p = 0.003), which remained significant in multilinear regression analysis (β = −0.155, p = 0.007). No correlation was observed between the acuteness-score and log(NT-proBNP) in patients with non-severe ischemia ( p = 0.529) or in the entire population ( p = 0.187). Conclusion In STEMI patients with severe ischemia, neurohormonal activation is inversely associated with ECG patterns of acute myocardial ischemia.
Abstract Objectives System delay (time from first medical contact to primary percutaneous coronary intervention) is associated with heart failure and mortality in patients with ST segment elevation ...myocardial infarction (STEMI). We evaluated the impact of system delay on left ventricular function (LVF) according to the combination of ischemia severity (Sclarovsky–Birnbaum grades) and acuteness (Anderson–Wilkins scores) in the pre-hospital electrocardiogram (ECG). Methods In a predefined secondary analysis of a prospective study, the severity and acuteness scores were performed on the pre-hospital ECG. Patients were assessed with respect to 4 classifications which were not mutually exclusive: severe ischemia (+ SI) or non-severe ischemia (− SI) and acute ischemia (+ AI) or non-acute ischemia (− AI). LVF was assessed by global longitudinal strain (GLS) within 48 hours of admission. Adjusted linear regression investigated the association of system delay with GLS in each group. Results In total 262 patients were eligible for analysis of the ECG, which resulted in 42 (16%) with (+ SI, − AI), 110 (42%) with (− SI, − AI), 90 (34%) with (− SI, + AI), and 20 (8%) patients with (+ SI, + AI). Although system delay did not differ between groups, patients with severe and non-acute ischemia had the most impaired LVF. System delay correlated weakly with GLS in the entire population (r = 0.133, p = 0.031), and well with GLS in the (+ SI, + AI) group (r = 0.456, p = 0.04), while there was no correlation in the other groups. By adjusted analysis, system delay predicted impaired GLS only in the (+ SI, + AI) group (β = 0.578, p = 0.002). Conclusion Pre-hospital risk stratification by ECG identifies patients with acute and severe ischemia who are at increased risk for reduced ventricular function (assessed by GLS) after STEMI. Optimizing reperfusion delays in these patients can therefore be of particular benefit in improving clinical outcome after STEMI.
PDF
