Assessment of Left Ventricular Diastolic Function by Transesophageal Echocardiography Before Cardiopulmonary Bypass: Clinical Implications of a Restrictive Profile

Evaluation of Intraoperative Left-Ventricular Diastolic Function by Myocardial Strain in On-Pump Coronary Artery Bypass Surgery

OBJECTIVES

Left ventricular (LV) diastolic function strongly predicts outcomes after cardiac surgery, but there is no consensus about appropriate intraoperative assessment. Recently, intraoperative diastolic strain-based measurements assessed by transesophageal echocardiography (TEE) have shown a strong correlation with LV relaxation, compliance, and filling, but there are no reports about evaluation through the entire perioperative period. Therefore, the authors describe the intraoperative course of this novel assessment technique in patients who underwent coronary artery bypass grafting, and compare it with conventional echocardiographic measures and common grading algorithms of LV diastolic dysfunction (LVDD).

DESIGN

Prospectively obtained data.

SETTING

A single university hospital.

PARTICIPANTS

Thirty adult patients scheduled for isolated on-pump coronary artery bypass grafting surgery with preoperative preserved left and right ventricular systolic function, without significant heart valve disease and pulmonary hypertension, and an uneventful intraoperative course were included.

INTERVENTIONS

Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Echocardiographic evaluation was performed in stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min.

MEASUREMENTS AND MAIN RESULTS

Strain-based measurements of peak longitudinal strain rate during isovolumetric relaxation (SR-IVR) and during early (SR-E) and late (SR-A) LV filling were assessed using EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway). Evaluation of conventional echocardiographic parameters included transmitral Doppler measures of early (E) and late (A) LV filling, as well as lateral-tissue Doppler velocity assessed during early (e´) and late (a´) LV filling, tricuspid regurgitation, and left atrial dilatation. Evaluation and grading of LV diastolic function by myocardial strain was feasible in all included patients at all time points of assessment. Using conventional grading algorithms, however, a substantial number of patients could not be sufficiently graded, falling into an indeterminate zone and not reliably estimating LVDD (T1, 40%; T2, 33%; T3, 36%). There was significant impairment of LV diastolic function after bypass, as measured by SR-IVR (T1 v T2, 0.28 s-1 [IQR 0.23; 0.31) v 0.18 s-1 [IQR 0.14; 0.22]; p < 0.001), SR-E (T1 v T2, 0.95 ± 0.34 s-1v 1.28 ± 0.36 s-1; p < 0.001), and E/SR-IVR (T1 v T2, 2.3 ± 1.0 m v 4.5 ± 2.1 m; p < 0.001]. Conventional echocardiographic measures remained unchanged during the same period (E/A T1 v T2, 1.27 [IQR 0.94; 1.59] v 1.21 [IQR 1.03; 1.47] [p = 1] and E/e´ T1 v T2, 7.0 [IQR 5.3; 9.6] v 6.35 [IQR 5.7; 9.9] [p = 0.9]). There were no significant changes in the values of SR-IVR, SR-E, SR-A, E/SR-IVR, E/A, and E/e´ before and after sternal closure (T2 v T3).

CONCLUSION

Intraoperative assessment of strain-based measurements of LV diastolic function and strain-based LVDD grading was feasible in this group of selected patients, whereas conventional parameters failed to describe LVDD sufficiently in a substantial number of patients. Diastolic strain-based measurements showed impairment of LV relaxation and compliance after bypass, which was not detected by conventional echocardiographic parameters. Therefore, diastolic myocardial strain analysis might be more sensitive in detecting myocardial diastolic dysfunction by TEE in the perioperative setting, with its dynamic changes of loading conditions, and might provide valuable and additional information on the perioperative changes of LV diastolic function.

Managing Diastolic Dysfunction Perioperatively

Preoperative cardiac evaluation is a cornerstone of the practice of anesthesiology. This consists of a thorough history and physical attempting to elucidate signs and symptoms of heart failure, angina or anginal equivalents, and valvular heart disease. Current guidelines rarely recommend preoperative echocardiography in the setting of an adequate functional capacity. Many patients may have poor functional capacity and/or have medical history such that echocardiographic data is available for review. Much focus is often placed on evaluating major valvular abnormalities and systolic function as measured by ejection fraction, but a key impactful component is often overlooked-diastolic function. A diagnosis of diastolic heart failure is an independent predictor of mortality and is not uncommon in patients with normal systolic function. This narrative review addresses the clinical relevance and management of diastolic dysfunction in the perioperative setting.

Intraoperative Circulatory Support in Lung Transplantation: Current Trend and Its Evidence

Lung transplantation has a high risk of haemodynamic complications in a highly vulnerable patient population. The effects on the cardiovascular system of the various underlying end-stage lung diseases also contribute to this risk. Following a literature review and based on our own experience, this review article summarises the current trends and their evidence for intraoperative circulatory support in lung transplantation. Identifiable and partly modifiable risk factors are mentioned and corresponding strategies for treatment are discussed. The approach of first identifying risk factors and then developing an adjusted strategy is presented as the ERSAS (early risk stratification and strategy) concept. Typical haemodynamic complications discussed here include right ventricular failure, diastolic dysfunction caused by left ventricular deconditioning, and reperfusion injury to the transplanted lung. Pre- and intra-operatively detectable risk factors for the occurrence of haemodynamic complications are rare, and the therapeutic strategies applied differ considerably between centres. However, all the mentioned risk factors and treatment strategies can be integrated into clinical treatment algorithms and can influence patient outcome in terms of both mortality and morbidity.

Consensus Defined Diastolic Dysfunction and Cardiac Postoperative Morbidity Score: A Prospective Observational Study

Diastolic dysfunction is associated with major adverse outcomes following cardiac surgery. We hypothesized that multisystem endpoints of morbidity would be higher in patients with diastolic dysfunction. A total of 142 patients undergoing cardiac surgical procedures with cardiopulmonary bypass were included in the study. Intraoperative assessments of diastolic function according to the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging guidelines using transesophageal echocardiography were performed. Cardiac Postoperative Morbidity Score (CPOMS) on days 3, 5, 8, and 15; length of stay in ICU and hospital; duration of intubation; incidence of new atrial fibrillation; 30-day major adverse cardiac and cerebrovascular events were recorded. Diastolic function was determinable in 96.7% of the dataset pre and poststernotomy assessment (n = 240). Diastolic dysfunction was present in 70.9% (n = 88) of measurements before sternotomy and 75% (n = 93) after sternal closure. Diastolic dysfunction at either stage was associated with greater CPOMS on D5 (p = 0.009) and D8 (p = 0.009), with CPOMS scores 1.24 (p = 0.01) higher than in patients with normal function. Diastolic dysfunction was also associated with longer durations of intubation (p = 0.001), ICU length of stay (p = 0.019), and new postoperative atrial fibrillation (p = 0.016, OR (95% CI) = 4.50 (1.22–25.17)). We were able to apply the updated ASE/EACVI guidelines and grade diastolic dysfunction in the majority of patients. Any grade of diastolic dysfunction was associated with greater all-cause morbidity, compared with patients with normal diastolic function.

Do Elderly Patients With Diastolic Dysfunction Require Higher Doses of Norepinephrine During General Anesthesia for Noncardiac Surgeries? A Prospective Observational Study

BACKGROUND

Diastolic dysfunction is a risk factor for postoperative major cardiovascular events. During anesthesia, patients with diastolic dysfunction might experience impaired hemodynamic function and worsening of diastolic function, which in turn, might be associated with a higher incidence of postoperative complications.We aimed to investigate whether patients with diastolic dysfunction require higher doses of norepinephrine during general anesthesia. Furthermore, we aimed to examine the association between the grade of diastolic dysfunction and the E/e' ratio during anesthesia. A high E/e' ratio corresponds to elevated filling pressures and is an important measure of impaired diastolic function.

METHODS

We conducted a prospective observational cohort study at a German university hospital from February 2017 to September 2018. Patients aged ≥60 years and undergoing general anesthesia (ie, propofol and sevoflurane) for elective noncardiac surgery were enrolled. Exclusion: mitral valve disease, atrial fibrillation, and implanted mechanical device.The primary outcome parameter was the administered dose of norepinephrine within 30 minutes after anesthesia induction (μg·kg-1 30 min-1). The secondary outcome parameter was the change of Doppler echocardiographic E/e' from ECHO1 (baseline) to ECHO2 (anesthesia). Linear models and linear mixed models were used for statistical evaluation.

RESULTS

A total of 247 patients were enrolled, and 200 patients (75 female) were included in the final analysis. Diastolic dysfunction at baseline was not associated with a higher dose of norepinephrine during anesthesia (P = .6953). The grade of diastolic dysfunction at baseline was associated with a decrease of the E/e' ratio during anesthesia (P < .001).

CONCLUSIONS

We did not find evidence for an association between diastolic dysfunction and impaired hemodynamic function, as expressed by high vasopressor support during anesthesia. Additionally, our findings suggest that diastolic function, as expressed by the E/e' ratio, does not worsen during anesthesia.

Effect of left ventricular diastolic dysfunction on development of primary graft dysfunction after lung transplant

PURPOSE OF REVIEW

Primary graft dysfunction (PGD) is one of the most common complications after lung transplant and is associated with significant early and late morbidity and mortality. The cause of primary graft dysfunction is often multifactorial involving patient, donor, and operational factors. Diastolic dysfunction is increasingly recognized as an important risk factor for development of PGD after lung transplant and here we examine recent evidence on the topic.

RECENT FINDINGS

Patients with end-stage lung disease are more likely to suffer from cardiovascular disease including diastolic dysfunction. PGD as result of ischemia-reperfusion injury after lung transplant is exacerbated by increased left atrial pressure and pulmonary venous congestion impacted by diastolic dysfunction. Recent studies on relationship between diastolic dysfunction and PGD after lung transplant show that patients with diastolic dysfunction are more likely to develop PGD with worse survival outcome and complicated hospital course.

SUMMARY

Patients with diastolic dysfunction is more likely to suffer from PGD after lung transplant. From the lung transplant candidate selection to perioperative and posttransplant care, thorough evaluation and documentation diastolic dysfunction to guide patient care are imperative.