Incremental value of the preoperative echocardiogram to predict mortality and major morbidity in coronary artery bypass surgery

Poor Agreement Between Preoperative Transthoracic Echocardiography and Intraoperative Transesophageal Echocardiography for Grading Diastolic Dysfunction

BACKGROUND

Guidelines for the evaluation and grading of diastolic dysfunction are available for transthoracic echocardiography (TTE). Transesophageal echocardiography (TEE) is used for this purpose intraoperatively but the level of agreement between these 2 imaging modalities for grading diastolic dysfunction is unknown. We assessed agreement between awake preoperative TTE and intraoperative TEE for grading diastolic dysfunction.

METHODS

In 98 patients undergoing cardiac surgery, key Doppler measurements were obtained using TTE and TEE at the following time points: TTE before anesthesia induction (TTEawake), TTE following anesthesia induction (TTEanesth), and TEE following anesthesia induction (TEEanesth). The primary endpoint was grade of diastolic dysfunction categorized by a simplified algorithm, and measured by TTEawake and TEEanesth, for which the weighted κ statistic assessed observed agreement beyond chance. Secondary endpoints were peak early diastolic lateral mitral annular tissue velocity (e'lat) and the ratio of peak early diastolic mitral inflow velocity (E) to e'lat (E/e'lat), measured by TTEawake and TEEanesth, were compared using Bland-Altman limits of agreement.

RESULTS

Disagreement in grading diastolic dysfunction by ≥1 grade occurred in 43 (54%) of 79 patients and by ≥2 grades in 8 (10%) patients with paired measurements for analysis, yielding a weighted κ of 0.35 (95% confidence interval [CI], 0.19-0.51) for the observed level of agreement beyond chance. Bland-Altman analysis of paired data for e'lat and E/e'lat demonstrated a mean difference (95% CI) of 0.51 (-0.06 to 1.09) and 0.70 (0.07-1.34), respectively, for measurements made by TTEawake compared to TEEanesth. The percentage (95% CI) of paired measurements for e'lat and E/e'lat that lay outside the [-2, +2] study-specified boundary of acceptable agreement was 36% (27%-48%) and 39% (29%-51%), respectively. Results were generally robust to sensitivity analyses, including comparing measurements between TTEawake and TTEanesth, between TTEanesth and TEEanesth, and after regrading diastolic dysfunction by the American Society of Echocardiography (ASE)/European Association of CardioVascular Imaging (EACVI) algorithm.

CONCLUSIONS

There was poor agreement between TTEawake and TEEanesth for grading diastolic dysfunction by a simplified algorithm, with disagreement by ≥1 grade in 54% and by ≥2 grades in 10% of the evaluable cohort. Future studies, including comparing the prognostic utility of TTEawake and TEEanesth for clinically important adverse outcomes that may be a consequence of diastolic dysfunction, are needed to understand whether this disagreement reflects random variability in Doppler variables, misclassification by the changed technique and physiological conditions of intraoperative TEE, or the accurate detection of a clinically relevant change in diastolic dysfunction.

Left Ventricular Diastolic Dysfunction and Pulmonary Hypertension: Outcomes in SAVR

BACKGROUND

Severe pulmonary hypertension (PH) and left ventricular diastolic dysfunction (LVDD) are independently associated with poor outcomes in cardiac surgery. We evaluated the relationship of several measures of LVDD, PH, and hemodynamic subtypes of PH including precapillary pulmonary hypertension(pcPH) and isolated post-capillary pulmonary hypertension(ipcPH) and combined pre and post capillary pulmonary hypertension(cpcPH) capillary PH to postoperative outcomes in a cohort of patients who underwent elective isolated-AVR.

METHODS

We evaluated (n = 206) patients in our local STS database who underwent elective isolated-AVR between 2014 and 2018, with transthoracic echocardiogram (n = 177) or right heart catheterization (n = 183) within 1 year of operation (or both, n = 161). The primary outcome was a composite end point of death, prolonged ventilation, ICU readmission, and hospital stay >14 days.

RESULTS

Severe PH was associated with worse outcomes (moderate: OR, 1.1, p = 0.09; severe: OR, 1.28, p = 0.01), but degree of LVDD was not associated with worse outcomes. Across hemodynamic subtypes of PH, odds of composite outcome were similar (p = 0.89), however, patients with cpcPH had more postoperative complications (67 vs. 36%, p = 0.06) and patients with ipcPH had greater all-cause mortality at 1 (8 vs. 1%, p = 0.03) and 3 years (27 vs. 4%, p = 0.008).

CONCLUSION

Severe PH conferred modestly greater risk of adverse events, and both LVDD grade and the combination of severe PH and LVDD were not associated with worse outcomes. However, hemodynamic stratification of PH revealed higher postoperative complications and worse long-term outcomes for those with cpcPH and ipcPH. Preoperative stratification of PH by hemodynamic subtype in valve replacement surgery may improve our risk stratification in this heterogenous condition. Further evaluation of the significance of LVDD and PH in other cardiac operations is warranted.

Right ventricular diastolic function predicts clinical atrial fibrillation after coronary artery bypass graft

Background

Patients with moderate-severe left ventricular systolic dysfunction undergoing coronary artery bypass graft (CABG) surgery are at high risk of mortality and morbidity. Our aim is to evaluate the right ventricular (RV) diastolic function in these patients, and monitor its effects on postoperation outcomes.

Materials and Methods

In a cohort study, patients with moderate-severe left ventricular systolic dysfunction (ejection fraction ≤35%) who were candidate for CABG were included. Baseline transthoracic echocardiography (TTE) was performed, and RV diastolic function measures were obtained. After CABG, the length of intubation, inotrope dependency, hospital stay in intensive care unit and ward, in-hospital and after discharge mortality, postoperative atrial fibrillation (POAF) were evaluated in all patients.

Results

Sixty-seven patients were prospectively included in the study. The mean ± standard deviation age of our patients was 61.4 ± 9.3. There was no difference between grades of RV diastolic function and postoperative outcomes. However, we found significant difference between grades of RV diastolic function and onset of in hospital, and total POAF (P-value = 0.017). Multivariate analysis demonstrated that preoperative tricuspidEt/E't (ratio of peak early-diastolic flow rate across the tricuspid valve orifice to peak early-diastolic velocity at the lateral tricuspid annulus), left atrial volume and "high risk" Euroscore II were independent predictors for POAF during hospitalization and total POAF in patients with moderate to severely impaired left ventricular systolic function (P-values were 0.04, 0.003 and 0.001, respectively).

Conclusion

We believe that patients with increased tricuspid Et/E't are high risk for POAF; therefore, any risk score for POAF should include a comprehensive TTE including evaluation of RV diastolic function before surgery.

Assessment of the left ventricular outflow tract during cardiac anaesthesia with biplane transoesophageal echocardiography: An observational study

BACKGROUND

Assessment of left ventricular outflow tract (LVOT) area is a key component of quantification of aortic stenosis and stroke volume. Current international guidelines recommend measurement of the LVOT diameter with two-dimensional (2D) echocardiography and assume a circle. This may lead to erroneous measures of aortic valve area and adversely affect peri-operative decision making. Multiplane orthogonal (biplane) and three-dimensional (3D) echocardiography imaging may allow more accurate calculation of LVOT, aortic valve area and stroke volume.

OBJECTIVE

To evaluate the shape and area of the LVOT with conventional 2D diameter, short axis cross-sectional planimetry with biplane imaging and 3D multiplane reconstruction in patients undergoing cardiac surgery with transoesophageal echocardiography (TOE).

DESIGN

A retrospective observational study.

SETTING

A single centre university hospital.

PATIENTS

119 patients undergoing cardiac surgery with TOE.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Measurements of the shape and area of the LVOT with standard 2D TOE, short axis biplane imaging and 3D TOE.

RESULTS

The LVOT shape is elliptical in 70% of patients. The (mean ± SD, [range]) LVOT cross-sectional area with 2D TOE was 4.29 cm2 ± 0.98, [2.46 to 6.70], with biplane was 4.68 cm2 ± 1.03, [2.92 to 7.30] and with 3D was 4.59 cm2 ± 0.99, [2.78 to 7.10]. There was a statistically significant difference (P < 0.001) in the three pairwise comparisons. 2D LVOT area had large bias (7 to 9%) and wider limits of agreement (LOA) with both biplane and 3D LVOT area (-17 to 36%). Biplane and 3D LVOT areas had small bias (1.8%) with relatively narrow LOA (-8 to 11%).

CONCLUSIONS

2D diameter measures of the LVOT assuming a circle underestimate LVOT area, underestimate aortic valve area and increase the apparent severity of aortic stenosis. This may lead to inappropriate aortic valve intervention. In a busy operating room environment, we suggest that for the calculation of stroke volume and aortic valve area, LVOT area is measured with biplane imaging.

TRIAL REGISTRATION

Observational study with no interventions so trial not registered.

Intraoperative diastolic function assessed by TEE does not agree with preoperative diastolic function grade in CABG patients

OBJECTIVE

To compare the agreement of the 2016 ASE/EACVI guidelines for grading diastolic dysfunction (DD) with the most commonly used intraoperative transesophageal echocardiography (TEE)-based diastolic function grading algorithm in cardiac surgical patients, and to describe the contribution of the echocardiographic variables used in the algorithms to any observed differences.

DESIGN

Retrospective data analysis.

SETTING

University tertiary medical center.

PARTICIPANTS

Hundred and one patients undergoing coronary artery bypass grafting (CABG) at a single institution from June 2017 to February 2019.

INTERVENTIONS

Preoperative transthoracic echocardiography (TTE) diastolic function grade determined by the 2016 American Society of Echocardiography (ASE)/European Association of Cardiovascular Imaging (EACVI) guidelines was compared to intraoperative diastolic function grade obtained by TEE.

MEASUREMENTS AND MAIN RESULTS

Incidence of DD on preoperative TTE was only 19.8%, while 62.3% of patients were graded as having DD on the intraoperative TEE exam. There was grade agreement between TTE and TEE in only 47/101 patients (46.5%). The McNemar test showed poor agreement between the two algorithms (OR for disagreement = 15.33, CI = 4.77-49.30; p < 0.0001). Despite the low incidence of DD on preoperative TTE, mean lateral e' values were significantly lower on TTE compared to TEE (7.7 cm/s vs 9.5 cm/s; p = < 0.0001).

CONCLUSIONS

There is strong disagreement between TTE and TEE-based DD grading algorithms. Due to the different echocardiographic variables used in each and the unique clinical settings in which they are applied, they produce fundamentally different results.

Pre-operative transthoracic echocardiography in ambulatory surgery-A cross-sectional study

BACKGROUND

Cardiac disease and aberrations in central volume status are risk factors for perioperative complications, and should be identified prior to surgery. This study investigated the benefit of transthoracic echocardiography (TTE) for pre-operative identification of cardiac disease and hypovolemia in ambulatory surgery.

METHODS

Ninety-six patients, with a mean age of 63.5 ± 12.2 years and body mass index of 27.0 ± 4.3 kg/m² , scheduled for ambulatory surgery (breast, thyroid, and minor gastrointestinal), were consecutively enrolled in this prospective observational study. Pre-operative comprehensive TTE was performed in order to assess heart failure (HF), asymptomatic left ventricular dysfunction, valvular disease, and aberrations in central volume status.

RESULTS

Pre-operative TTE identified a total of 28 cases of HF, 13 cases of HF with reduced or moderately reduced, ejection fraction (EF), and 15 cases of HF with preserved EF. Furthermore, 46 cases of asymptomatic left ventricular (LV) dysfunction were identified. 44/96 patients were hypovolemic, 16 of whom in severe hypovolemia. Seven cases of previously unknown obstructive valvular or myocardial disease and six cases of right ventricular systolic dysfunction were identified. A total of 24% (23/96) were classified as potential critical hemodynamic findings. The number needed (NNT) to treat for pre-operative TTE in order to find one critical finding was 4.2.

CONCLUSION

In this ambulatory surgical cohort, a high prevalence of pre-operative LV dysfunction and aberrations in volume status was observed. The results demonstrate that pre-operative TTE contributed valuable hemodynamic information. The standard pre-operative assessment for this cohort might need to be revised.

Application of strain and other echocardiographic parameters in the evaluation of early and long-term clinical outcomes after cardiac surgery revascularization

Background

Coronary artery bypass graft (CABG) surgery is an effective therapeutic strategy for coronary heart disease (CHD). Myocardial longitudinal strain echocardiography with 2D speckle tracking could obtain ventricular function with better accuracy and reliability than the left ventricular ejection fraction.

The aim of the study was to assess changes in left ventricular function in patients before and after surgical revascularization for a 24-month period of observation, using echocardiography with speckle tracking strain imaging. We searched for echocardiographic predictors of poor early and long-term outcome after CABG.

Methods

We enrolled 69 patients scheduled for elective coronary bypass grafting. Patients were divided into groups based on pre-operative systolic and diastolic parameters, depending on the GLS value and the E’ Lat and E/E’ value. The correlation between these parameters and early and long-term outcomes was analyzed.

Results

Preoperative EF was preserved in 86, 95% (60) patients. Pre-operative reduced GLS was observed in 73.91% (51) of patients and severely reduced in 31.88% (22).

In the first post-operative 6-month period, we observed a significant decrease in the GLS. The GLS was a predictor of early postoperative outcome for intubation time, the inotropes use and length of ICU stay. Diastolic dysfunction was a predictor of the greater inotrope requirements.

Conclusions

Global longitudinal strain and diastolic dysfunction parameters are a good predictors of worse early outcome after CABG.

Pre-operative right ventricular echocardiographic parameters associated with short-term outcomes and long-term mortality after CABG

Background This analysis aims to assess the prognostic value of pre-operative right ventricular echocardiographic parameters in predicting short-term adverse outcomes and long-term mortality after coronary artery bypass graft (CABG). Methods Study design: Observational retrospective cohort. Pre-operative echocardiographic data, perioperative adverse outcomes (POAO) and long-term mortality were retrospectively analyzed in 491 patients who underwent isolated CABG at a single academic center between 2006 and 2014. Results Average age of enrolled subjects was 66 ± 11.5 years with majority being male (69%). 227/491 patients had 30 days POAO (46%); most common being post-operative atrial fibrillation (27.3%) followed by prolonged ventilation duration (12.7%). On multivariate analysis, left atrial volume index ≥42 mL/m2 (LAVI) (OR (95% CI): 1.98 (1.03-3.82), P = 0.04), mitral E/A >2 (1.97 (1.02-3.78), P = 0.04), right atrial size >18 cm2 (1.86 (1.14-3.05), P = 0.01), tricuspid annular plane systolic excursion (TAPSE) <16 mm (1.8 (1.03-3.17), P = 0.04), right ventricular systolic pressure (RVSP) ≥36 mmHg (pulmonary hypertension) (1.6 (1.03-2.38), P = 0.04) and right ventricle myocardial performance index (RVMPI) >0.55 (1.58 (1.01-2.46), P = 0.04) were found to be associated with increased 30-day POAO. On 3.5-year follow-up, cumulative survival was decreased in patients with myocardial performance index (MPI) ≥0.55 (log rank: 4.5, P = 0.034) and in patients with mitral valve E/e' ≥14 (log rank: 4.9, P = 0.026). Conclusion Pre-operative right ventricle dysfunction (RVD) is associated with increased perioperative complications. Furthermore, pre-operative RVD and increased left atrial pressures are associated with long-term mortality post CABG.

Diastolic dysfunction is common and predicts outcome after cardiac surgery

Background

Diastolic dysfunction (DD) identified on echocardiography predicts mortality after cardiac surgery, however the most useful diastolic parameters for assessment and the association of DD with prolonged mechanical ventilation, ICU re-admission, and hospital length of stay are not established.

Methods

We included patients that underwent coronary artery bypass grafting (CABG), aortic valve replacement (AVR) or a combined procedure (CAB-AVR) from 2010 to 2016, and who had preoperative transthoracic echocardiography (TTE) at our institution within 6 months of the operation. Diastolic function was graded using the transmitral E and A waves and the septal tissue Doppler velocity. We performed logistic regression to assess the association of grade of DD with a composite endpoint of death, prolonged mechanical ventilation, ICU readmission during hospitalization, and hospital length of stay longer than 14 days.

Results

Between 2010 and 2016, 577 patients were eligible for inclusion. DD was common, with 42% of the cohort manifesting grade II or grade III DD. Rates of death and prolonged ventilation increased across grades of DD and across quartiles of increasing LV filling pressure, assessed by the E/e’ ratio. Adjusting for age, sex, procedure, systolic and diastolic function, both systolic (odds ratio 0.68 95% CI 0.55–0.85 per inter-quartile increase in LVEF) and diastolic function (odds ratio 1.31 95% CI 1.04–1.66 per increasing DD grade) both independently predicted outcome.

Conclusion

Diastolic dysfunction is common among patients undergoing cardiac surgery and is associated with death, prolonged mechanical ventilation, and prolonged hospital and ICU length of stay independent of systolic dysfunction.

Which echocardiographic parameters improve the risk prediction for peri-operative outcomes in patients undergoing coronary bypass surgery: a prospective study

OBJECTIVE

To assess the performance of transthoracic echocardiographic parameters to predict operative mortality and morbidity in patients undergoing coronary artery bypass grafting, and to assess its incremental prognostic value as compared to the Society of Thoracic Surgeons (STS) score.

MATERIALS AND METHODS

We prospectively collected the clinical and biological data required to calculate the STS score in patients hospitalised for coronary artery bypass grafting. Preoperative transthoracic echocardiography was performed for each patient. The primary endpoint was 30-day mortality or major morbidity (i.e. stroke, renal failure, prolonged ventilation, deep sternal wound infection, reoperation) as defined by the STS. The secondary endpoint was prolonged hospitalisation for over 14 days.

RESULTS

A total of 172 patients was included (mean age 66.1±10.2 years, 12.2% were women). The primary endpoint occurred in 33 patients (19.2%), and 28 patients (16.3%) had a prolonged hospital stay. Independent predictive factors for the primary endpoint were an increased left atrial volume (>31 mL/m²; odds ratio (OR) 3.55, 95% confidence interval (CI) 1.38-9.12; P=0.004) and a decreased tricuspid annular plane systolic excursion (<20 mm; OR 3.45, 95% CI 1.47-8.21; P=0.008). The predictive value of the multivariate model increased when the two echocardiographic parameters were added to the STS score (area under the curve 0.598 vs. 0.695, P=0.001; integrated discrimination improvement 7.44%).

CONCLUSION

In patients undergoing coronary artery bypass grafting, preoperative assessment of left atrial size and tricuspid annular plane systolic excursion should be performed systematically, as it provides additional prognostic information to the STS score.

Temporal Trends in Predictors of Early and Late Mortality After Emergency Coronary Artery Bypass Grafting for Cardiogenic Shock Complicating Acute Myocardial Infarction

BACKGROUND

Cardiogenic shock after acute myocardial infarction is an indication for emergent coronary artery bypass grafting in patients not amenable to percutaneous coronary intervention. Our study aimed to evaluate and identify risk factors for early and long-term outcomes in such patients.

METHODS

A total of 508 patients who underwent coronary artery bypass grafting for cardiogenic shock complicating acute myocardial infarction between January 2000 and June 2014 were divided into 3 time cohorts: 2000 to 2004 (n=204), 2005 to 2009 (n=166), and 2010 to 2014 (n=138). Predictors of in-hospital mortality for each time cohort and long-term mortality for all patients were identified by logistic and Cox regression analyses, respectively.

RESULTS

Mean age was 68.3±9.8 years. Of the 508 patients, 78.5% had 3-vessel and 47.1% had left main disease. Left ventricular function <30% was observed in 44.1% of patients, with 30.4%, 37.9%, 52.9%, and 3.1% requiring preoperative resuscitation, ventilation, intra-aortic balloon pump, and extracorporeal membrane oxygenation support, respectively. Overall in-hospital mortality was 33.7%; declined from 42.2% to 30.7% to 24.6%, respectively, for the 3 time cohorts (P=0.02); and was independently predicted by serum lactate >4 mmol/L (odds ratio [OR], 4.78; 95% confidence interval, 2.88-7.95; P<0.0001), ST-segment-elevation myocardial infarction (OR, 2.10; 95% confidence interval, 1.36-3.26; P=0.001), age >75 years (OR, 2.01; 95% confidence interval, 1.06-3.85; P=0.03), and left ventricular ejection fraction <30% (OR, 1.83; 95% confidence interval, 1.15-2.91; P=0.01). Cumulative survival was 42.6±2.0% and 33.4±2.0% at 5 and 10 years, respectively, and correspondingly improved to 64.3±3.0% and 49.8±3.0% in hospital survivors. Serum lactate >4 mmol/L (OR, 2.2; P<0.0001), incremental age (OR, 1.05; P<0.0001), New York Heart Association class IV (OR, 1.33; P=0.02), diabetes mellitus (OR, 1.39; P=0.005), and preoperative inotropic (OR, 2.61; P=0.001) and extracorporeal membrane oxygenation (OR, 1.68; P=0.05) support predicted late mortality.

CONCLUSIONS

Emergency coronary artery bypass grafting in patients with acute myocardial infarction complicated by cardiogenic shock is associated with a high in-hospital mortality, which showed a significant decline with time. Hospital survivors have good long-term outcomes, which demonstrate the beneficial effect of surgical revascularization. Preoperative serum lactate >4 mmol/L is a strong predictor of both early and late mortality.

Echo for diastology

Diastolic dysfunction ranging from impaired relaxation of the left ventricle to heart failure with preserved ejection fraction (HFpEF) is a common finding in the cardiac surgery population. It is important for the peri-operative echocardiographer to have a developed understanding of the pathophysiology of diastolic dysfunction and the echocardiographic features that determine where on the spectrum of diastolic function and dysfunction a patient lies

Interval Changes in Myocardial Performance Index Predict Outcome in Severe Sepsis

OBJECTIVES

Septic cardiomyopathy is a well-described consequence of septic shock and is associated with increased sepsis-related mortality. The myocardial performance index (MPI), a parameter derived from echocardiographic tissue Doppler measurements, allows for a more sensitive assessment of global cardiac function than do traditional metrics for cardiac function. The authors hypothesized that changes in left ventricular MPI in patients with severe sepsis would be associated with a higher 90-day mortality.

DESIGN

Prospective, observational study.

SETTING

Intensive care units of a tertiary medical center.

PARTICIPANTS

The study comprised 47 patients admitted with new diagnoses of severe sepsis or septic shock.

INTERVENTIONS

All patients underwent transthoracic echocardiograms with assessment of MPI at enrollment and 24 hours later. Hemodynamic data and information on sepsis-related mortality were collected. In the primary analysis, the association between change in MPI from enrollment to 24 hours and sepsis-related 90-day mortality was assessed.

MEASUREMENTS AND MAIN RESULTS

Of the 47 patients enrolled, 30 demonstrated an improvement in MPI from 0 to 24 hours ("improved" group), and MPI worsened in the remaining 17 patients ("worsened" group). Despite no significant differences in ejection fraction or severity of illness, the median MPI at enrollment in the "improved" group was higher than baseline values in the "worsened" group (p = 0.005). A worsening MPI over the 24-hour study interval was associated with increased mortality at 90 days (p = 0.04), which remained significant (hazard ratio 3.72; 95% confidence interval 1.12-12.41; p = 0.03) after adjusting for severity of illness (Acute Physiology and Chronic Health Evaluation II score), intravenous fluids, and vasopressor use.

CONCLUSIONS

In patients admitted to the intensive care unit with a diagnosis of severe sepsis or septic shock, a worsening MPI during the first 24 hours after intensive care unit admission was associated with higher 90-day mortality.

Derivation and Validation of Prognosis-Based Age Cutoffs to Define Elderly in Cardiac Surgery

Background—

The age cutoff to define elderly is controversial in cardiac surgery, empirically ranging from ≥65 to ≥80 years. Beyond semantics, this has important implications as a starting point for clinical care pathways and inclusion in trials. We sought to characterize the relationship between age and adverse outcomes in patients undergoing cardiac surgery and to derive and validate prognosis-based age cutoffs.

Methods and Results—

Six thousand five hundred seventy one consecutive adult patients undergoing cardiac surgery at 3 hospitals in the United States and Canada were included in the cohort. Logistic regression models and generalized additive models with thin-plate splines were fit to the data. The age distribution was 50 to 59 years in 1244 (18.9%), 60 to 69 years in 2144 (32.6%), 70 to 79 years in 2000 (30.4%), ≥80 years in 1183 (18.0%) patients. After controlling for sex and type of operation, the relationship between age and 30-day operative mortality was found to be nonlinear. Receiver operating characteristic analysis showed that the optimal cutoffs to identify older patients at higher risk of operative mortality were greater than 74, 78, and 75 years for isolated coronary bypass, isolated valve surgery, and coronary bypass plus valve surgery, respectively. These age cutoffs were validated in an independent cohort.

Conclusions—

The relationship between age and operative mortality is not linear, manifesting a steeper rise after age 75 for coronary bypass and approaching octogenarian age for isolated valve surgery. Rather than using arbitrary age cutoffs to define elderly, the outcomes-based cutoff of ≥75 years should be used to identify the population of older adults that has higher risk and may benefit from preoperative geriatric evaluation and optimization.

Echocardiographic Predictors of Immediate Postoperative Outcomes in Patients With Severe Left Ventricular Systolic Dysfunction Undergoing On-Pump Coronary Artery Bypass Grafting

OBJECTIVES

The postoperative course following on-pump coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) systolic dysfunction is often unpredictable. Therefore, the aim of this study was to identify predictors of poor postoperative outcome in this subset of patients.

DESIGN

Prospective observational study SETTING: Single university hospital PARTICIPANTS: Forty patients with severe LV systolic dysfunction undergoing isolated on-pump CABG INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Comprehensive transesophageal echocardiographic examination was performed to obtain the indices of systolic and diastolic LV function after induction of anesthesia. A poor postoperative outcome was defined as patient death or vasoactive inotropic score≥20 for at least 6 hours and/or requiring intra-aortic balloon counterpulsation and/or mechanical ventilation for≥24 hours. Poor postoperative outcome was observed in 40% (16/40) of patients. Patients with poor postoperative outcomes had a significantly higher systolic dyssynchrony index, septal-lateral delay with a significantly lower global longitudinal strain and isovolumic acceleration, end-diastolic volume, end-systolic volume, and lateral and medial mitral annulus systolic velocity. In a binary logistic regression model, global longitudinal strain (odds ratio, 1.5, confidence interval [CI] 95%, 1.19-1.88, p = 0.001), septal-lateral delay (odds ratio, 1.02, 95% CI, 1.01-1.03; p = 0.001) and systolic dyssychrony index (odds ratio, 1.3, 95% CI, 1.13-1.48; p = 0.000) were found to be predictors of poor postoperative outcome.

CONCLUSION

Global longitudinal strain, systolic dyssynchrony index, and septal-lateral delay were reliable and accurate predictors of adverse outcomes in patients with severe LV systolic dysfunction undergoing on-pump CABG.

Monitoring diastolic dysfunction using a simplified algorithm in patients undergoing off-pump coronary artery bypass grafting surgery

Context:

Left ventricle diastolic dysfunction (LVDD) is gaining importance as useful marker of mortality and morbidity in cardiac surgical patients. Different algorithms have been proposed for the intraoperative grading of DD. Knowledge of the particular grade of DD has clinical implications with the potential to modify therapy, but there is a paucity of literature on the role of diastolic function evaluation during off-pump coronary artery bypass grafting (OPCABG) surgery.

Aims:

The aim of this study was to monitor changes in LVDD using simplified algorithm proposed by Swaminathan et al. in patients undergoing OPCABG.

Settings and Design:

The study was conducted in a tertiary care level hospital; this was a prospective, observational study.

Subjects and Methods:

Fifty consecutive patients undergoing OPCABG were enrolled. Hemodynamic and echocardiographic parameters were measured at 6 stages in every patient namely after anesthetic induction (baseline), during left internal mammary artery (LIMA) to left anterior descending (LAD) grafting (LIMA → LAD), saphenous vein graft (SVG) to obtuse marginal (OM) grafting (SVG → OM), SVG to posterior descending artery (PDA) grafting (SVG → PDA), during proximal anastomosis of SVG to aorta, and postprotamine. The patients were classified in grades of LVDD as per simplified algorithm proposed by Swaminathan et al. using only intraoperatively measured E and E’.

Results:

The success rate of measurement and classification of LVDD was 98.92% (277 out of 280 measurements). The grades of LVDD varied significantly as per surgical steps with maximum downgrading occurring during OM and LAD grafting. During OM grafting, none of the patients had normal diastolic function while 29% of patients exhibited restrictive pattern (Grade 3 LVDD). Patients with normal baseline LV diastolic function also exhibited downgrading during OM and LAD grafting. Postprotamine, 37% of patients with normal baseline diastolic function continued to exhibit some degree of DD.

Conclusions:

The LVDD changes dynamically during various stages of OPCABG, which can be successfully monitored with simplified algorithm.

Noninvasive estimation of left atrial pressure with transesophageal echocardiography

BACKGROUND

The pulmonary artery catheter (PAC) has historically been used to measure cardiac filling pressures of which pulmonary capillary wedge pressure (PCWP) has been used as a surrogate of left atrial pressure (LAP) and left ventricular end-diastolic pressure. Increasingly, the use of the PAC has been questioned in the perioperative period with multiple large studies unable to clearly demonstrate benefit in any group of patients, resulting in a declining use in the perioperative period. Alternative methods for the noninvasive estimation of left-sided filling pressures are required. Echocardiography has been used to provide noninvasive estimation of PCWP and LAP, based on evaluating mitral inflow velocity with the E and A waves and looking at movement of the mitral annulus with tissue Doppler (e').

AIM

The aim of our study was to assess the relationship between PCWP and E/e' in cardiac surgical patients with transesophageal echocardiography (TOE).

DESIGN

A prospective observational study.

SETTING

Cardiac surgical patients in a single quaternary referral university teaching hospital.

METHODS

The ratio of mitral inflow velocity (E wave) to mitral annular tissue velocity (e') (the E/e' ratio) and PCWP of 91 patients undergoing general anesthesia and cardiac surgery were simultaneously recorded, with the use of TOE and a PAC.

RESULTS

The correlation between E/e' and PCWP was modest with a Spearman rank correlation coefficient of 0.29 (P = 0.005). The area under the receiver operating characteristic curve for using E/e' to predict elevated PCWP (≥18 mmHg) was 0.6825 (95% confidence interval: 0.57-0.80), indicating some predictive utility. The optimum threshold value of E/e' was 10 which had 71% sensitivity and 60% specificity to predict a PCWP ≥18 mmHg.

CONCLUSIONS

Noninvasive measurements of E/e' in general cardiac surgical patients have only a modest correlation and does not reliably estimate PCWP.

Risk Prediction in Aortic Valve Replacement: Incremental Value of the Preoperative Echocardiogram

Background

Risk prediction is a critical step in patient selection for aortic valve replacement (AVR), yet existing risk scores incorporate very few echocardiographic parameters. We sought to evaluate the incremental predictive value of a complete echocardiogram to identify high‐risk surgical candidates before AVR.

Methods and Results

A cohort of patients with severe aortic stenosis undergoing surgical AVR with or without coronary bypass was assembled at 2 tertiary centers. Preoperative echocardiograms were reviewed by independent observers to quantify chamber size/function and valve function. Patient databases were queried to extract clinical data. The cohort consisted of 432 patients with a mean age of 73.5 years and 38.7% females. Multivariable logistic regression revealed 3 echocardiographic predictors of in‐hospital mortality or major morbidity: E/e’ ratio reflective of elevated left ventricular (LV) filling pressure; myocardial performance index reflective of right ventricular (RV) dysfunction; and small LV end‐diastolic cavity size. Addition of these echocardiographic parameters to the STS risk score led to an integrated discrimination improvement of 4.1% (P<0.0001). After a median follow‐up of 2 years, Cox regression revealed 5 echocardiographic predictors of all‐cause mortality: small LV end‐diastolic cavity size; LV mass index; mitral regurgitation grade; right atrial area index; and mean aortic gradient <40 mm Hg.

Conclusions

Echocardiographic measures of LV diastolic dysfunction and RV performance add incremental value to the STS risk score and should be integrated in prediction when evaluating the risk of AVR. In addition, findings of small hypertrophied LV cavities and/or low mean aortic gradients confer a higher risk of 2‐year mortality.

Sex differences in the prevalence of diastolic dysfunction in cardiac surgical patients

OBJECTIVES

The mortality from diastolic dysfunction is approximately 9% to 28%. In patients with ischemic heart disease, female sex and advanced age are associated with increases in ventricular diastolic stiffness. Clinical studies have found higher rates of diastolic dysfunction in women, despite higher ejection fractions, than in men post-myocardial infarction. Therefore, we hypothesized that female patients undergoing cardiac surgery have higher degrees of diastolic dysfunction and experience more adverse outcomes, such as prolonged hospitalization.

METHODS

We prospectively enrolled 153 patients undergoing cardiac surgery. Diastolic function was assessed using early transmitral velocity (E) and early diastolic lateral mitral annular tissue velocity (e'). Left ventricular diastolic dysfunction was defined as binary and a continuous outcome (E/e').

RESULTS

Females were more likely than males to present with higher E/e' (11.5 vs. 7.9, p = 0.001) and higher left ventricular diastolic dysfunction (71% vs. 36%, p < 0.001). The addition of sex to the model for left ventricular diastolic dysfunction was significant. The relationship between sex and E/e' ratio showed the biggest difference between males and females in the 56-72-year-old age brackets, where women were much more likely to have a higher E/e' than males.

CONCLUSIONS

We identified a significantly higher prevalence of diastolic dysfunction among females presenting for elective cardiac surgery compared to males. This finding is more pronounced with age. Additionally, we found that female sex is at higher risk of prolonged ICU and hospital length of stay.

Interatrial septum motion but not Doppler assessment predicts elevated pulmonary capillary wedge pressure in patients undergoing cardiac surgery

BACKGROUND

Left atrial pressure and its surrogate, pulmonary capillary wedge pressure (PCWP), are important for determining diastolic function. The role of transthoracic echocardiography (TTE) in assessing diastolic function is well established in awake subjects. The objective was to assess the accuracy of predicting PCWP by TTE and transesophageal echocardiography (TEE) during coronary artery surgery.

METHODS

In 27 adult patients undergoing on-pump coronary artery surgery, simultaneous echocardiographic and hemodynamic measurements were obtained immediately before anesthesia (TTE), after anesthesia and mechanical ventilation (TTE and TEE), during conduit harvest (TEE), and after separation from cardiopulmonary bypass (TEE).

RESULTS

Twenty patients had an ejection fraction (EF) of 0.5 or greater. With the exception of E/e' and S/D ratios, echocardiographic values changed over the echocardiographic studies. In patients with low EF, E velocity, deceleration time, pulmonary vein D, S/D, and E/e' ratios correlated well with PCWP before anesthesia. After induction of anesthesia using TTE or TEE, correlations were poor. In normal EF patients, correlations were poor for both TEE and TTE at all five stages. The sensitivity and specificity of echocardiographic values were not high enough to predict raised PCWP except for a fixed curve pattern of interatrial septum (area under the curve 0.89 for PCWP ≥ 17, and 0.98 for ≥ 18 mmHg) and S/D less than 1 (area under the curve 0.74 for PCWP ≥ 17, and 0.78 for ≥ 18 mmHg).

CONCLUSION

Doppler assessment of PCWP was neither sensitive nor specific enough to be clinically useful in anesthetized patients with mechanical ventilation. The fixed curve pattern of the interatrial septum was the best predictor of raised PCWP.

Predicting major adverse cardiac events in spine fusion patients: is the revised cardiac risk index sufficient?

STUDY DESIGN

Observational cohort study.

OBJECTIVE

To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more.

SUMMARY OF BACKGROUND DATA

Preoperative cardiac testing is extensively guided by the RCRI, which was developed and validated in thoracic, abdominal, and orthopedic surgical patients. Because multilevel spine fusion surgery is often associated with major transfusion, we hypothesize that the RCRI may not accurately characterize the risk of cardiovascular morbidity in these patients.

METHODS

After institutional review board approval, perioperative data were collected from 547 patients who underwent 3 or more levels of spinal fusion with instrumentation. Postoperative cardiac morbidity was defined as any combination of the following: arrhythmia requiring medical treatment, myocardial infarction (either by electrocardiographic changes or troponin elevation), or the occurrence of demand ischemia. The surgical complexity was categorized as anterior surgery only, posterior cervical and/or thoracic fusion, posterior lumbar fusion, or any surgery that included transpedicular osteotomies. Logistic regression analysis was performed to determine RCRI performance.

RESULTS

The RCRI performed no better than chance (area under the curve = 0.54) in identifying the 49 patients (9%) who experienced cardiac morbidity.

CONCLUSION

The RCRI did not predict cardiac morbidity in our patients undergoing major spine fusion surgery, despite being extensively validated in low-risk noncardiac surgical patients. Preoperative testing and optimization decisions, previously based on the RCRI, may need to be revised to include more frequent functional cardiac imaging and more aggressive implementation of pharmacologic modalities that may mitigate cardiac morbidity, similar to the preoperative evaluation for major vascular surgery.

LEVEL OF EVIDENCE

3.

Usefulness of right ventricular dysfunction to predict new-onset atrial fibrillation following coronary artery bypass grafting

Postoperative atrial fibrillation (AF) is a serious yet common complication after coronary artery bypass grafting (CABG) surgery. Risk factors for postoperative AF have been identified, including echocardiographic parameters, and these are relied on to implement preventative strategies that reduce the incidence of AF. There has yet to be a study examining the impact of echocardiographic right-sided cardiac parameters on the prediction of postoperative AF. Thus, a panel of right-sided cardiac parameters was measured in a cohort of patients undergoing isolated CABG surgery, excluding those who did not have echocardiographic assessment within 30 days before surgery and those with any history of AF. The primary outcome was postoperative AF defined as any episode of AF requiring treatment during the index hospitalization. Postoperative AF occurred in 197 of 768 patients (25.6%); these were older and more likely to have hypertension and chronic kidney disease. After adjustment for clinical and echocardiographic variables, left atrial volume index ≥34 ml/m(2) (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.36 to 2.87), abnormal right ventricular myocardial performance index (OR 1.50, 95% CI 1.01 to 2.24), and advancing age (OR 1.05, 95% CI 1.03 to 1.07) were found to be independent predictors of postoperative AF. In conclusion, right ventricular myocardial performance index is a novel predictor of postoperative AF in patients undergoing isolated CABG surgery and appears to be additive to established risk factors such as age and left atrial volume.