Echocardiographic determinants of left ventricular ejection fraction after acute myocardial infarction

Prognostic value of summed motion score assessed by gated SPECT myocardial perfusion imaging in patients with dilated cardiomyopathy

Background

The prognosis of patients with dilated cardiomyopathy (DCM) is poor and new indicators are urgently needed to predict lethal cardiac events. This study aimed to investigate the value of summed motion score (SMS) in predicting cardiac death of DCM patients using gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

Methods and results

Eighty-one patients with DCM who underwent 99mTc-MIBI gated SPECT MPI were retrospectively enrolled and were divided into cardiac death and survivor groups. The functional parameters of left ventricle including SMS were measured using quantitative gated SPECT software. During the follow-up period of 44 (25, 54) months, 14 (17.28%) cardiac deaths were observed. Compared with the survivor group, SMS was significantly higher in the cardiac death group. Multivariate cox regression analysis showed that SMS was an independent predictor for cardiac death (HR 1.34, 95% CI 1.02–1.77, P = 0.034). SMS also provided incremental prognostic value over other variables in the multivariate model as determined by likelihood ratio global chi-squared test. In the Kaplan-Meier survival analysis, the event-free survival rate was significantly lower in the high-SMS (HSMS) group than the low-SMS (LSMS) (log-rank P < 0.001). Furthermore, the area under curve (AUC) of SMS was larger than that of LVEF at the 12th month of follow-up (0.85 vs. 0.80, P = 0.045).

Conclusion

SMS is an independent predictor of cardiac death in DCM patients and provides incremental prognostic value. SMS might have higher predictive value than LVEF for early cardiac death.

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, β = - 0.196, p = 0.001) and a larger increase in LVEDV (mean ∆ = 33.18 mL, β = 0.135, p = 0.012). Meanwhile patients with Cx lesion were significantly associated with a larger decrease in E/e' (mean ∆ = 2.6, β = - 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.

Fully Automated Cardiac Assessment for Diagnostic and Prognostic Stratification Following Myocardial Infarction

Background

Cardiovascular magnetic resonance imaging is considered the reference methodology for cardiac morphology and function but requires manual postprocessing. Whether novel artificial intelligence–based automated analyses deliver similar information for risk stratification is unknown. Therefore, this study aimed to investigate feasibility and prognostic implications of artificial intelligence–based, commercially available software analyses.

Methods and Results

Cardiovascular magnetic resonance data (n=1017 patients) from 2 myocardial infarction multicenter trials were included. Analyses of biventricular parameters including ejection fraction (EF) were manually and automatically assessed using conventional and artificial intelligence–based software. Obtained parameters entered regression analyses for prediction of major adverse cardiac events, defined as death, reinfarction, or congestive heart failure, within 1 year after the acute event. Both manual and uncorrected automated volumetric assessments showed similar impact on outcome in univariate analyses (left ventricular EF, manual: hazard ratio [HR], 0.93 [95% CI 0.91–0.95]; P<0.001; automated: HR, 0.94 [95% CI, 0.92–0.96]; P<0.001) and multivariable analyses (left ventricular EF, manual: HR, 0.95 [95% CI, 0.92–0.98]; P=0.001; automated: HR, 0.95 [95% CI, 0.92–0.98]; P=0.001). Manual correction of the automated contours did not lead to improved risk prediction (left ventricular EF, area under the curve: 0.67 automated versus 0.68 automated corrected; P=0.49). There was acceptable agreement (left ventricular EF: bias, 2.6%; 95% limits of agreement, −9.1% to 14.2%; intraclass correlation coefficient, 0.88 [95% CI, 0.77–0.93]) of manual and automated volumetric assessments.

Conclusions

User‐independent volumetric analyses performed by fully automated software are feasible, and results are equally predictive of major adverse cardiac events compared with conventional analyses in patients following myocardial infarction.

Registration

URL: https://www.clinicaltrials.gov; Unique identifiers: NCT00712101 and NCT01612312.

The early diastolic myocardial velocity: a marker of increased risk in patients with coronary heart disease

OBJECTIVE

Tissue Doppler imaging (TDI) is a promising echocardiographic modality allowing quantification of myocardial performance. However, the prognostic potential of TDI in patients with acute myocardial infarction (AMI) is not yet investigated. We sought to explore the ability of TDI in identifying patients at risk for new cardiovascular events after AMI.

METHODS

One hundred and nineteen patients with AMI were recruited prospectively (mean age 61 years; range 32-81 years of age). Patients with diabetes mellitus (DM) were excluded. Echocardiography was performed 3-12 months after AMI. Two-dimensional (2-D) and TDI variables were recorded. The patients were followed during a mean period of 4·6 years (range 1-8 years). The primary end-point was defined as any of the following: death from any cause, non-fatal reinfarction or stroke, unstable angina pectoris, congestive heart failure requiring hospitalization and coronary revascularization procedure.

RESULTS

Thirty patients had some form of cardiovascular events during follow-up. Seven patients had cardiovascular death, 13 patients had reinfarction and four patients had a stroke. New angina or unstable angina was recorded in 21 patients. Of these patients, 13 underwent percutaneous coronary angioplasty (PCI) or coronary artery bypass grafting (CABG). The early diastolic myocardial velocity (E(m)) emerged as the only echocardiographic variable that offered a clear differentiation between patients that presented with new cardiovascular (CV) events as compared to the corresponding group without any CV events at follow-up (P<0·05). In multivariate statistical analysis and after adjustment for age, sex, total cholesterol, body mass index (BMI) and other baseline characteristics, Em remained as independent predictors of CV events (HR, 1·18, 95% CI, 1·02-1·36; P<0·05). However, none of the investigated variables evolved as an independent predictor of cardiovascular morbidity and mortality.

CONCLUSION

E(m) appears to be a sensitive echocardiographic index in identifying non-diabetic patients with AMI at risk of new cardiovascular events.

The Prognostic Significance of Resting Regional Left Ventricular Function in Patients With Varying Degrees of Myocardial Ischemia

Background

Our aim was to determine whether regional left ventricular (LV) function on a resting transthoracic echo (TTE) provides prognostic information in patients with varying degrees of ischemia on myocardial perfusion imaging.

Methods

Between 2004 - 2009, we identified 503 patients (mean age 69 (SD 11); 79% male) with reversible ischemia on a myocardial SPECT scan who had a TTE within 30 days. We evaluated the rate of subsequent revascularization and death for all patients.

Results

Following the SPECT scan and TTE, 246/503(49%) patients underwent revascularization, 64/503 (13%) patients died, 369 (73%) patients had a normal left ventricular ejection fraction (LVEF), 242 (48%) patients had a resting wall motion abnormality (WMA), 21/261 (8%) with no WMA died compared to 43/242 (18%) in patients with a WMA. In patients with a WMA (n = 242) there was no significant difference in mortality when comparing patients with small (< 6 segments) and large (> 6 segments) WMA (P = 0.44). In patients with moderate/severe ischemia, the presence of a resting WMA was associated with a higher mortality rate (18% v 7%; P = 0.005). In a multivariable model, LVEF (< 50%) was associated with a hazard ratio of 2.2 (P = 0.002, 95% CI 1.34 - 3.68) however, WMA and number of abnormal segments did not reach statistical significance.

Conclusion

A resting wall motion abnormality in patients with moderate/severe ischemia is associated with a higher mortality compared to patients with mild ischemia on myocardial perfusion imaging. Regional left ventricular dysfunction unlike LVEF was not an independent predictor of mortality.

Assessing myocardial recovery following ST-segment elevation myocardial infarction: short- and long-term perspectives using cardiovascular magnetic resonance

Myocardial recovery after revascularization for ST-segment elevation myocardial infarction (STEMI) remains a significant diagnostic and, despite novel treatment strategies, a therapeutic challenge. Cardiovascular magnetic resonance (CMR) has emerged as a valuable clinical and research tool after acute STEMI. It represents the gold standard for functional and morphological evaluation of the left ventricle. Gadolinium-based perfusion and late-enhancement viability imaging has expanded our knowledge about the underlying pathologies of inadequate myocardial recovery. T2-weighted imaging of myocardial salvage after early reperfusion of the infarct-related artery underlines the effectiveness of current invasive treatment for STEMI. In the last decade, the number of publications on CMR after acute STEMI continued to rise, with no plateau in sight. Currently, CMR research is gathering robust prognostic data on standardized CMR protocols with the aim to substantially improve patient care and prognosis. Beyond established CMR protocols, more specific methods such as magnetic resonance relaxometry, myocardial tagging, 4D phase-contrast imaging and novel superparamagnetic contrast agents are emerging. This review will discuss the currently available data on the use of CMR after acute STEMI and take a brief look at developing new methods currently under investigation.

Effect of left ventricular scar size, location, and transmurality on left ventricular remodeling with healed myocardial infarction

Studies of patients with acute myocardial infarction (MI) suggest that anterior transmural infarcts are associated with greater left ventricular (LV) remodeling compared with nontransmural nonanterior infarctions. It is unclear whether this relation also exists in long-term survivors of MI. Cardiac magnetic resonance imaging was used to explore the relation between myocardial scar size, localization, transmurality, and degree of long-term LV remodeling in patients with healed MI. Subjects were recruited from a registry of patients with healed MI who participated in the OPTIMAAL trial. Cardiac magnetic resonance imaging was performed to assess LV mass, volumes, LV ejection fraction, and myocardial scarring, adjusting for myocardial ischemia. Fifty-seven patients (mean age 69 +/- 10 years mean ejection fraction 49 +/- 13%) were studied 4.4 +/- 0.4 years after MI. Anterior scar was found in 19 patients and nonanterior scar in 33, whereas 5 patients did not show myocardial scar. Transmural scar was evident in 36 patients. In the 52 patients with scar, average total scar size was 13 +/- 8% of total LV mass. There was a strong linear relation between scar size and LV end-diastolic volume index (r = 0.81, p <0.0001), end-systolic volume index (r = 0.86, p <0.0001), and LV ejection fraction (r = -0.74, p <0.0001). In multivariate analysis, scar size was the strongest independent predictor of ejection fraction and LV volumes independently of scar localization and transmurality. In conclusion, in the studied cohort, there was a linear relation between scar size and ejection fraction and LV volumes. This relation was independent of scar location and transmurality.

Lack of Additional Benefit of Intracoronary Transplantation of Autologous Peripheral Blood Stem Cell in Patients With Acute Myocardial Infarction

BACKGROUND

Recently the potential of myocardial repair by transplantation of autologous bone marrow stem cells has been suggested. Whether the additional intracoronary transplantation of autologous peripheral blood stem cells (PBSC), which were mobilized by granulocyte-colony-stimulating factor (G-CSF), could safely improve myocardial function in patients with acute myocardial infarction (AMI) was investigated.

METHODS AND RESULTS

Seventy-three patients with AMI who had successfully undergone percutaneous coronary intervention (PCI) were enrolled in the present prospective nonrandomized open-labeled study. Ten patients with elective PCI received G-CSF for 4 days followed by intracoronary PBSC transplantation. Thirty-two patients with primary PCI and 31 patients with recent AMI and elective PCI served as controls. The left ventricular (LV) function was evaluated using echocardiography and magnetic resonance imaging. G-CSF and intracoronary transplantation of PBSC did not incur any periprocedural myocardial damage. After 6 months, the LV ejection fraction was significantly improved in the cell therapy group. For 2 years of the follow-up period, there was no adverse clinical events, except one asymptomatic in-stent restenosis. However, comparable improvement of the LV ejection fraction was also identified in the primary PCI and elective PCI control groups.

CONCLUSIONS

In the present study, additional intracoronary infusion of PBSC was safe and feasible for the patients with AMI who had undergone PCI, but did not lead to a significant improvement in LV function compared to standard reperfusion treatment.

Stroke Complicating Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction

BACKGROUND

Stroke associated with percutaneous coronary intervention (PCI) is a tragic complication. Despite advances in the practice of PCI, the incidence of stroke complicating PCI has not changed over the decades. The objective of the present study was to evaluate incidence and correlates of stroke occurring in patients with myocardial infarction (MI) undergoing PCI.

METHODS AND RESULTS

Stroke was defined as the presence of any new focal neurological deficit lasting > or =24 h that occurred anytime during or after PCI until discharge. In 2,281 consecutive patients with PCIs for non-ST-elevation MI, or ST-elevation MI (STEMI), 20 strokes were identified (0.88%). Strokes were ischemic in 95%. On multivariate analyses, ejection fraction < or =30% (odds ratio =4.3, p=0.003) was the only independent predictor for stroke. In patients who developed stroke within 24 h of PCI, PCI of vein grafts was more frequent, and use of glycoprotein IIb/IIIa inhibitor was less frequent. Those patients tended to present late in the course of MI. Stroke found more than 24 h after PCI was related to diabetes, higher serum creatinine, lower ejection fraction, anterior wall STEMI and emergency use of intra-aortic balloon pumps.

CONCLUSIONS

Low ejection fraction was the only independent predictor for stroke, but risk factors for periprocedural stroke are different from those of stroke occurring more than 24 h after PCI. Upstream use of glycoprotein IIb/IIIa inhibitor might decrease the risk of periprocedural stroke.

Impact of infarct location on left ventricular ejection fraction after correction for enzymatic infarct size in acute myocardial infarction treated with primary coronary intervention

BACKGROUND

Left ventricular function and infarct size are strong predictors for prognosis after acute myocardial infarction (MI). Anterior MI is associated with greater reduction of left ventricular ejection fraction (LVEF) and worse prognosis. Our objective was to study whether the impact of infarct size on global LVEF is dependent of infarct location.

METHODS

We analyzed 888 patients treated with primary percutaneous coronary intervention for acute MI. Enzymatic infarct size and LVEF within 1 week were measured. In 490 patients (55%), LVEF was measured a second time at 6 months.

RESULTS

Every 1000 U/L of cumulative lactate dehydrogense release corresponded to a decrease of 4.7% (95% CI 4.1-5.3) in LVEF measured within 1 week post MI for left anterior descending coronary artery (LAD)-related infarcts and to a decrease of 2.4% (95% CI 1.7-3.1) in LVEF measured within 1 week post MI for non-LAD-related infarcts (P < .0001). Left ventricular ejection fraction measured 6 months post MI showed a decrease for every 1000 U/L cumulative lactate dehydrogense release of 4.8% (95% CI 4.2-5.3) for LAD and 2.4% (95% CI 1.7-3.1) for non-LAD-related infarcts (P < .0001). Multivariate correction for relevant clinical and angiographic data did not change these results.

CONCLUSION

In patients with a first acute MI treated with primary percutaneous coronary intervention, LAD-related infarcts show for a similar amount of myocardial necrosis as determined by enzymatic infarct size, a lower residual LVEF when compared with non-LAD-related infarcts.

Wall motion score index and ejection fraction for risk stratification after acute myocardial infarction

BACKGROUND

The prognostic importance of regional systolic function, as assessed by wall motion score index (WMSI), compared with global function, as assessed by left ventricular ejection fraction (LVEF), has not been assessed in large populations after acute myocardial infarction.

METHODS

Echocardiograms, including the assessment of WMSI and LVEF, were performed in 767 patients with acute myocardial infarction at a median of 1 day (25th and 75th percentiles 0-2 days) after admission. Patients were followed for a median of 19 months (range 12-28 months). Cox proportional hazards models were constructed for the primary study end point (all-cause mortality) and for a secondary end point (hospitalization for congestive heart failure).

RESULTS

During follow-up (median 40 months; range 32-50 months), 216 patients died and 54 patients were hospitalized for congestive heart failure. By univariate analysis, both LVEF (P < .0001) and WMSI (P < .0001) were powerful predictors of all-cause mortality. By a forward conditional Cox model, WMSI proved to be an independent predictor of death (hazard ratio 1.15 per 0.2-unit increase, 95% CI 1.10-1.21, P < .0001). When WMSI was included in the model, LVEF did not provide additional prognostic information (P = .77). Wall motion score index also proved to be an independent predictor of hospitalization for congestive heart failure (hazard ratio 1.21 per 0.2-unit increase, 95% CI 1.07-1.37, P = .002), whereas LVEF did not (P = .56).

CONCLUSION

Both LVEF and WMSI provide powerful prognostic information after acute myocardial infarction; however, the predictive power of WMSI is greater.

Correlation of the Tei Index With Left Ventricular Dilatation and Mortality in Patients With Acute Myocardial Infarction

The Tei index is an echocardiographic index of combined systolic and diastolic function, calculated as isovolumetric relaxation time plus isovolumetric contraction time divided by ejection time. The aim of this study was to define the correlation of the Tei index with left ventricular dilatation and mortality in patients with acute myocardial infarction (AMI). A total of 77 patients (58 men, 19 women) with a mean age of 53 +/- 12 years, who had presented with an AMI in our clinic between June 2001 and February 2002 were compared with a control group of 88 healthy subjects (63 men, 25 women) with a mean age of 55 +/- 6 years. Echocardiographic evaluation was carried out within 24 hours and the third month of AMI, using a 3.5 MHz probe with pulse wave Doppler recordings by the adult cardiac mode of an Acuson C 256 echocardiograph. There were statistically significant differences between the 2 groups in all echocardiographic parameters, except mitral A wave. Thirteen patients died during the follow-up period of 3 months. The Tei index was significantly higher in the patients who died compared with those who survived (0.70 +/- 0.10 versus 0.61 +/- 0.10; P < 0.001). The patients who had heart failure after AMI had a mean Tei index value of 0.76 +/- 0.27, whereas the patients who did not have heart failure after AMI had a significantly lower Tei index value of 0.60 +/- 0.32 (P < 0.05). Patients were divided into 2 groups according to their Tei index. Patients with a > 0.60 Tei index had significantly higher end-systolic and end-diastolic volumes compared to patients with a < 0.60 Tei index (P < 0.001 for both) in the acute phase of AMI. Within 3 months, patients with a Tei index < 0.60 had a significant reduction in end-diastolic volumes (P < 0.01), whereas the end-diastolic volumes did not change significantly in patients with an index > 0.60 (P = 0.19). The Tei index is an important indicator of left ventricular dysfunction and death after AMI. A greater Tei index at the onset of AMI is associated with a higher incidence of subsequent cardiac death, CHF, and progressive LV remodeling.

Determination of Asymmetric Cavity Volumes Using Real-Time Three-Dimensional Echocardiography: An In Vitro Balloon Model Study

OBJECTIVES

We designed a new in vitro model to test the accuracy and reproducibility of real-time three-dimensional (RT3D) ultrasound imaging for determining a variety of asymmetric cavity volumes with aneurysm.

METHODS

Fifteen individual balloon models mimicking ventricular aneurysm were filled with water (170-322.5 ml) without air bubbles and kept in a compressor pump. Compression of the models produced only a change in shape of the balloon and no change in volume. The models were scanned with RT3D echocardiography (RT3DE) and the images recorded on an optical disk. Volumes were measured off line in two phases; maximal compression, where there was maximal change in shape and nil compression, where there was minimal or no change in shape. Volumes were measured by manual tracing technique of the inner border of B-scan images and compared with the drained volume of water from the balloon.

RESULTS

There was a high correlation between the drained volume and measured volume at maximal compression (equivalent to end-systole, r = 0.99, y = 0.99x + 3.69, SEE = 6.5 ml), between the drained volume and measured volume at nil compression (equivalent to end-diastole, r = 0.99, y = 0.94x + 12.07, SEE = 5.9 ml), and between volumes measured at maximal and nil compressions (r = 0.99, y = 0.94x + 10.55, SEE = 4.6 ml).

CONCLUSION

The results of this experiment show that RT3DE can accurately measure the volumes of a variety of asymmetric ventricular cavities.