Composite Echocardiographic Score to Predict Long-Term Survival Following Myocardial Infarction.

BACKGROUND: Whilst the left ventricular ejection fraction (LVEF) remains the primary echocardiographic measure widely utilised for risk stratification following myocardial infarction (MI), it has a number of well recognised limitations. The aim of this study was to compare the prognostic utility of a composite echocardiographic score (EchoScore) composed of prognostically validated measures of left-ventricular (LV) size, geometry and function, to the utility of LVEF alone, for predicting survival following MI. METHODS: Retrospective data on 394 consecutive patients with a first-ever MI were included. Comprehensive echocardiography was performed within 24 hours of admission for all patients. EchoScore consisted of LVEF<50%, left atrial volume index>34 mL/m2, average E/e >14, E/A ratio>2, abnormal LV mass index, and abnormal LV end-systolic volume index. A single point was allocated for each measure to derive a score out of 6. The primary outcome measure was all-cause mortality. RESULTS: At a median follow-up of 24 months there were 33 deaths. On Kaplan-Meier analysis, a high EchoScore (>3) displayed significant association with all-cause mortality (log-rank χ2=74.48 p<0.001), and was a better predictor than LVEF<35% (log-rank χ2=17.01 p<0.001). On Cox proportional-hazards multivariate analysis incorporating significant clinical and echocardiographic predictors, a high EchoScore was the strongest independent predictor of all-cause mortality (HR 6.44 95%CI 2.94-14.01 p<0.001), and the addition of EchoScore resulted in greater increment in model power compared to addition of LVEF (model χ2 56.29 vs 44.71 p<0.001, Harrell's C values 0.83 vs 0.79). CONCLUSIONS: A composite echocardiographic score composed of prognostically validated measures of LV size, geometry, and function is superior to LVEF alone for predicting survival following MI.

Accuracy of Cardiac Nurse Acquired and Measured Three-Dimensional Echocardiographic Left Ventricular Ejection Fraction: Comparison to Echosonographer.

BACKGROUND: Three-dimensional echocardiography (3D-Echo) performed by novice health care staff to measure left ventricular ejection fraction (LVEF) could allow cost-effective screening and monitoring for left ventricular systolic dysfunction (LVSD) prior to the development of heart failure. The aim of this study was to determine feasibility and accuracy of cardiac nurses (after completing focussed training) independently acquiring 3D-Echo images, and measuring LVEF using semi-automated software when compared to an echosonographer. METHODS: One echosonographer and three cardiac nurses acquired 3D-Echo images on 73 patients (62 ± 16 years, 62% male) with good image quality, and subsequently measured LVEF using a semi-automated algorithm. RESULTS: Overall feasibility was 89% with the three nurses successfully acquiring 3D-Echo images suitable for LVEF assessment in 65 of the 73 patients. High accuracy (r = 0.82; p < 0.0001) with minimal bias (+0.1, -10.6 to +10.8 limits of agreement; p = 0.91) was observed comparing the nurses to the echosonographer for measuring LVEF. Individual nurses demonstrated high feasibility (86%-92%), accuracy (r = 0.83-0.87; all p < 0.0001) and intra-observer reproducibility (r = 0.96-0.97; all p < 0.0001), with good inter-observer consistency in accuracy compared to the echosonographer (one-way analysis of variance p = 0.559). CONCLUSIONS: We have demonstrated that, following a focussed training protocol, it was feasible for cardiac nurses to acquire 3D-Echo images of sufficient image quality to allow measurement of LVEF using a semi-automated algorithm, with comparable accuracy and intra-observer variability to an expert echosonographer. This could potentially allow the broader application of echocardiography to screen for LVSD in high-risk cohorts.

Evaluation of training nurses to perform semi-automated three-dimensional left ventricular ejection fraction using a customised workstation-based training protocol.

AIMS AND OBJECTIVES: We aimed to determine the feasibility of training cardiac nurses to evaluate left ventricular function utilising a semi-automated, workstation-based protocol on three dimensional echocardiography images. BACKGROUND: Assessment of left ventricular function by nurses is an attractive concept. Recent developments in three dimensional echocardiography coupled with border detection assistance have reduced inter- and intra-observer variability and analysis time. This could allow abbreviated training of nurses to assess cardiac function. DESIGN: A comparative, diagnostic accuracy study evaluating left ventricular ejection fraction assessment utilising a semi-automated, workstation-based protocol performed by echocardiography-naïve nurses on previously acquired three dimensional echocardiography images. METHODS: Nine cardiac nurses underwent two brief lectures about cardiac anatomy, physiology and three dimensional left ventricular ejection fraction assessment, before a hands-on demonstration in 20 cases. We then selected 50 cases from our three dimensional echocardiography library based on optimal image quality with a broad range of left ventricular ejection fractions, which was quantified by two experienced sonographers and the average used as the comparator for the nurses. Nurses independently measured three dimensional left ventricular ejection fraction using the Auto lvq package with semi-automated border detection. RESULTS: The left ventricular ejection fraction range was 25-72% (70% with a left ventricular ejection fraction <55%). All nurses showed excellent agreement with the sonographers. Minimal intra-observer variability was noted on both short-term (same day) and long-term (>2 weeks later) retest. CONCLUSIONS: It is feasible to train nurses to measure left ventricular ejection fraction utilising a semi-automated, workstation-based protocol on previously acquired three dimensional echocardiography images. Further study is needed to determine the feasibility of training nurses to acquire three dimensional echocardiography images on real-world patients to measure left ventricular ejection fraction. RELEVANCE TO CLINICAL PRACTICE: Nurse-performed evaluation of left ventricular function could facilitate the broader application of echocardiography to allow cost-effective screening and monitoring for left ventricular dysfunction in high-risk populations.

Salivary Protein Panel to Diagnose Systolic Heart Failure.

Screening for systolic heart failure (SHF) has been problematic. Heart failure management guidelines suggest screening for structural heart disease and SHF prevention strategies should be a top priority. We developed a multi-protein biomarker panel using saliva as a diagnostic medium to discriminate SHF patients and healthy controls. We collected saliva samples from healthy controls (n = 88) and from SHF patients (n = 100). We developed enzyme linked immunosorbent assays to quantify three specific proteins/peptide (Kallikrein-1, Protein S100-A7, and Cathelicidin antimicrobial peptide) in saliva samples. The analytical and clinical performances and predictive value of the proteins were evaluated. The analytical performances of the immunoassays were all within acceptable analytical ranges. The multi-protein panel was able to significantly (p < 0.001) discriminate saliva samples collected from patients with SHF from controls. The multi-protein panel demonstrated good performance with an overall diagnostic accuracy of 81.6% (sensitivity of 79.2% and specificity of 85.7%) when distinguishing SHF patients from healthy individuals. In conclusion, we have developed immunoassays to measure the salivary concentrations of three proteins combined as a panel to accurately distinguish SHF patients from healthy controls. While this requires confirmation in larger cohorts, our findings suggest that this three-protein panel has the potential to be used as a biomarker for early detection of SHF.

Echocardiographic predictors of all-cause mortality in patients with left ventricular ejection fraction >35%: Value of guideline based assessment of diastolic dysfunction.

BACKGROUND: Recent data suggests that the majority of cardiac deaths in patients with heart failure occur in patients with a left ventricular ejection fraction (LVEF) >35%. This study sought to determine the value of guideline based assessment of diastolic dysfunction in predicting all-cause mortality in patients with a first-ever myocardial infarction (MI) with an LVEF >35%. METHODS: A retrospective single centre study involving 383 patients with a first-ever MI (STEMI or NSTEMI) with LVEF >35% was performed. Clinical, angiographic and echocardiographic data were obtained from prospectively maintained institutional databases. Outcomes data were obtained from national death registry. Echocardiography was performed early post-admission for all patients. Significant diastolic dysfunction (DD) was defined was grade 2/3 diastolic dysfunction according to current American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. RESULTS: At a median follow up of 2 years, there were 32 deaths. On Cox proportional hazards multivariate analysis incorporating significant clinical variables (age, chronic kidney disease and extent of coronary artery disease), significant DD (HR 2.57, 95%CI 1.16-5.68, p = 0.020) and left ventricular end-diastolic volume index (HR 1.03, 1.04-1.07, p = 0.021) were the only independent echocardiographic predictors of all-cause mortality. Intermodel comparisons using model χ2 and Harrel's-C confirmed incremental value of DD. In the subgroup with LVEF 36-55% (n = 176), significant DD was the only independent echocardiographic predictor (HR 3.56, 95%CI 2.46-9.09, p = 0.006). CONCLUSIONS: The presence of significant DD identifies patients with LVEF >35% following MI who are at a higher risk of all-cause mortality, and who may benefit from further risk stratification and treatment.

Diastolic Dysfunction Assessed Using Contemporary Guidelines and Prognosis Following Myocardial Infarction.

BACKGROUND: Recent American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines for the assessment of diastolic dysfunction (DD) recommend a simplified approach with four key variables incorporated into a novel diagnostic algorithm. The aim of this study was to assess the prognostic value of significant DD assessed using the algorithm recommended in the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines (DD2016) in comparison with the prognostic value of significant DD assessed using the 2009 guidelines (DD2009) as well as the individual parameters incorporated in the 2016 algorithm. METHODS: Retrospective data on 419 consecutive patients with first ever myocardial infarction were included. Doppler echocardiography was performed within 24 hours of admission in all patients. Significant DD was defined as grade 2 or 3 DD. The primary outcome measure was composite major adverse cardiovascular events (MACEs), comprising death, myocardial infarction, and heart failure. RESULTS: At a median follow-up of 24 months, there were 61 MACEs. On Kaplan-Meier analysis, DD2016 showed a better association with MACEs than DD2009 (log-rank χ2 = 21.01 [P < .001] vs 13.13 [P = .001]). On Cox proportional-hazards multivariate analysis incorporating significant clinical predictors and left ventricular ejection fraction, DD2016 (hazard ratio, 2.22; 95% CI, 1.25-3.98; P = .007) was the strongest independent predictor of MACEs, whereas DD2009 (hazard ratio, 1.63; 95% CI, 0.95-2.80; P = .074) was not a significant predictor. Of the four key diastolic parameters, only left atrial volume index was independently associated with MACEs (hazard ratio, 1.79; 95% CI, 1.02-3.14; P = .041) when included in a Cox proportional-hazards multivariate model incorporating significant clinical predictors and left ventricular ejection fraction, although the association was weaker than DD2016. Intermodel comparisons with model χ2 and Harrell's C statistic were satisfactory for DD2016. CONCLUSIONS: Significant DD assessed using the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines is a robust independent predictor of clinical outcomes following myocardial infarction and compares favorably with DD2009 as well as the individual parameters incorporated in the novel 2016 algorithm.