Diastolic dysfunction, diagnostic and perioperative management in cardiac surgery

Left Ventricular Diastolic Dysfunction in Cardiac Surgery: A Narrative Review

Cardiac relaxation is a complex process that involves various interconnected characteristics and, along with contractile properties, determines stroke volume. Perioperative ischemia-reperfusion injury and left ventricular diastolic dysfunction (DD) are characterized by the left ventricle's inability to receive a sufficient blood volume under adequate preload. Baseline DD and perioperative DD have an impact on postoperative complications, length of hospital stay, and major clinical outcomes in a variety of cardiac pathologies. Several baseline and perioperative factors, such as age, female sex, hypertension, left ventricle hypertrophy, diabetes, and perioperative ischemia-reperfusion injury, contribute to the risk of DD. The recommended diagnostic criteria available in guidelines have not been validated in the perioperative settings and still need clarification. Timely diagnosis of DD might be crucial for effectively treating postoperative low cardiac output syndrome. This implies the need for an individualized approach to fluid infusion strategy, cardiac rate and rhythm control, identification of extrinsic causes, and administration of drugs with lusitropic effects. The purpose of this review is to consolidate scattered information on various aspects of diastolic dysfunction in cardiac surgery and provide readers with well-organized and clinically applicable information.

Preoperative echocardiography as a predictor of spinal anesthesia-induced hypotension in older patients with mild left ventricular diastolic dysfunction: a retrospective observational study

BACKGROUND

Spinal anesthesia-induced hypotension (SAH) frequently occurs in older patients, many of whom have mild left ventricular (LV) diastolic dysfunction, often asymptomatic at rest. This study investigated the association between preoperative echocardiographic measurements and SAH in older patients with mild LV diastolic dysfunction.

METHODS

We conducted a retrospective observational study using data from electronic medical records. The patients ≥ 65 years old who underwent spinal anesthesia for urologic surgery between January 2016 and December 2017 and whose preoperative echocardiography within 6 months before surgery revealed grade I LV diastolic dysfunction were recruited. SAH was investigated using the anesthesia records. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed.

RESULTS

A total of 163 patients were analyzed. SAH and significant SAH developed in 55 (33.7%) patients. The mitral inflow E velocity was an independent risk factor for SAH (odds ratio [OR], 0.886; 95% confidence interval [CI], 0.845-0.929; P < 0.001). The area under the ROC curve for mitral inflow E velocity to predict SAH was 0.819 (95% CI, 0.752-0.875; P < 0.001). If mitral inflow E velocity was ≤ 60 cm/s, SAH was predicted with a sensitivity of 83.6% and specificity of 70.4%.

CONCLUSIONS

The preoperative mitral inflow E velocity demonstrated the greatest predictability of SAH in older patients with mild LV diastolic dysfunction. This may assist in identifying patients at high risk of SAH and guiding preventive strategies in the future.

Echocardiographic Probability of Pulmonary Hypertension in Cardiac Surgery Patients—Occurrence and Association with Respiratory Adverse Events—An Observational Prospective Single-Center Study

Background: Pulmonary hypertension (PH) is an independent risk factor of increased morbidity and mortality in cardiac surgery patients (CS). The most common cause underlying PH is left ventricular (LV) diastolic dysfunction. This study aimed to evaluate the echocardiographic probability of PH in patients undergoing CS and its correlation with postoperative respiratory adverse events (RAE). Methods: The echocardiographic probability of PH and its correlation with LV diastolic dysfunction was assessed in 56 consecutive adult patients who were qualified for coronary artery bypass grafting (CABG). Later, the postoperative RAE (such as pneumonia, pulmonary congestion, or hypoxemia), the length of intensive care unit (ICU) treatment and mortality in groups with moderate or high (PH-m/h) and low (PH-l) probability of pulmonary hypertension were examined. Results: PH-m/h was observed in 29 patients, of whom 65.5 % had LV diastolic dysfunction stage II or III. A significantly higher occurrence of RAE was observed in the PH-m/h group as compared to the PH-l group. There were no differences between the PH-m/h and PH-l patient groups regarding the in-hospital length of stay or mortality. Conclusions: High or intermediate probability of PH is common in cardiac surgical patients with left ventricular diastolic dysfunction and correlates with respiratory adverse events.

Perioperative Cardiac Risk Reduction in Noncardiac Surgery

Major adverse cardiovascular events are a significant source of morbidity and mortality in the perioperative setting, estimated to occur in approximately 5% of patients undergoing nonemergent noncardiac surgery. To minimize the incidence and impact of these events, careful attention must be paid to preoperative cardiovascular assessment to identify patients at high risk of cardiovascular complications. Once identified, cardiovascular risk reduction is achieved through optimization of medical conditions, appropriate management of medication, and careful monitoring to allow for early identification of-and intervention for-any new conditions that would increase the risk of adverse cardiovascular outcomes. The major cardiovascular and anesthesiology societies in the United States, Europe, and Canada have published guidelines for perioperative management of patients undergoing noncardiac surgery. However, since publication of these guidelines, there has been a practice-changing evolution in the medical literature. In this review, we attempt to reconcile the recommendations made in these 3 comprehensive guidelines, while updating recommendations, based on new evidence, when available.

Cardiac Stress in High-Risk Patients Undergoing Major Endovascular Surgery-Focus on Diastolic Function

OBJECTIVES

The purpose of this study was to determine the relationship between the changes in diastolic function and their association with cardiac biomarkers in the perioperative period in patients undergoing complex endovascular aortic repair.

DESIGN

Prospective observational study.

SETTING

Single-center academic hospital, central teaching hospital in Warsaw, Poland.

PARTICIPANTS

The study comprised 27 high-risk patients scheduled for elective endovascular repair of aortic aneurysm.

INTERVENTIONS

Complex endovascular procedure using branched endograft of the thoracoabdominal aorta. Branches of the stent grafts included renal arteries, the superior mesenteric artery, and the celiac trunk.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was to evaluate changes in diastolic function parameters assessed with transthoracic echocardiography at two and 24 hours postoperatively. The major secondary outcomes were changes in N-terminal pro-B-type natriuretic peptide (NT-proBNP) and troponin I concentrations, systolic function parameters, hemodynamic parameters at two and 24 hours, length of hospital stay, and 30-day mortality. There was a reduction in e' wave velocity on both the septal and lateral sides at two hours compared with the baseline (p = 0.041 and p = 0.05, respectively). There was an increase in both NT-proBNP and troponin I concentrations after surgery (p = 0.002 and p = 0.034, respectively), with troponin I peaking two hours after surgery and NT-proBNP peaking 24 hours after surgery.

CONCLUSIONS

Patients undergoing a branched endovascular aortic repair of a thoracoabdominal aortic aneurysm experience a cardiac insult that manifests with deterioration in diastolic parameters and concomitant increases of troponin and NT-proBNP concentrations. Additional large-scale prospective studies are required to confirm this phenomenon.

Pulmonary complications following cardiac surgery

Coronary heart disease is a common diseases of atherosclerosis. Despite the development of noninvasive therapies and the advancement of pharmacological methods and extensive drug regimens, coronary artery bypass grafting surgery is still the ultimate treatment option in many patients. Among the various complications following open heart surgery, one of the common difficulties is pulmonary complications associated with subsequent morbidity and mortality, which should be studied according to preoperative, perioperative, and postoperative factors. Preoperative factors include genetics, age, family history of pulmonary disease, smoking, coexisting disease, etc. Perioperative factors include surgical procedures like sternotomy incision, cardioplegia, and internal mammary artery harvesting; anaesthesia procedure effects like pulmonary collapse, maintenance drugs and morphine administration; and cardiopulmonary bypass pump by systemic inflammatory response syndromes. And finally, postoperative factors, especially mediastinitis and the role of nursing in the intensive care unit. Pulmonary complications after cardiac surgery include atelectasis, pleural effusions, pneumonia, pulmonary oedema, cardiogenic pulmonary oedema, acute respiratory distress syndrome, pulmonary embolism, phrenic nerve injury, pneumothorax, sternal wound infection, and mediastinitis, with different outbreaks in patients reported. Although the preoperative, perioperative, and postoperative factors play an important role in the occurrence of these complications, the preoperative factors, as factors that can be adjusted, should be considered more than the others and explained to the patient, and the preoperative patient’s assessment should be noted. Also, postoperative care with the goal of reducing infections and pulmonary complications should be addressed by the nursing team.

Diastolic dysfunction of the left ventricle - a practical approach for an anaesthetist

Bedside point-of-care echocardiography is being increasingly incorporated in peri-operative assessment and in intensive care units. Because of availability of tissue Doppler imaging in the modern ultrasound machines there has been an increased interest in research of diastolic function of left ventricle. The diastolic function is crucial for the hemodynamically effective function of the heart. Diastolic dysfunction is a well-established risk factor of the major adverse cardiac events during perioperative period, complications during weaning from ventilator and prognostic factor of mortality in septic shock.

Immediate Preoperative Transthoracic Echocardiography for the Prediction of Postoperative Atrial Fibrillation in High-Risk Cardiac Surgery

OBJECTIVE

The present study aimed to validate the utility of bedside cardiac ultrasound to identify patients for the risk of postoperative atrial fibrillation (POAF).

DESIGN

A prospective cohort study of consecutive patients.

SETTING

Single-center tertiary referral center.

PARTICIPANTS

After Institutional Review Board consent, 169 patients undergoing elective cardiac surgery were enrolled in the study.

INTERVENTIONS

A preoperative transthoracic echocardiographic interrogation assessing diastolic function was performed. Measurements were assessed offline with experienced echocardiographers blinded to clinical outcomes.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was POAF during the first 72 hours after surgery. A total of 169 patients completed the study, 44 of whom (26.0%) developed POAF, and 39 (25.2%) had diastolic dysfunction. Patients with POAF had a higher rate of postoperative heart failure, reintubation within 24 hours of surgery, and length of stay (p = 0.002, 0.01, and 0.0006, respectively). Predictors significant for POAF included increasing age, left atrial volume indexed to body surface area (LAVI), and diastolic dysfunction (p = 0.02, 0.0001, and 0.001, respectively). Multivariate spline regressions demonstrated a nonlinear correlation between increasing LAVI and risk of POAF.

CONCLUSION

Left atrial volume can be assessed efficiently preoperatively to provide superior risk stratification over clinical factors and diastolic parameters alone for the prediction of POAF. Furthermore, the present study demonstrated that the cutoffs of chamber quantification currently used do not appropriately capture the increased risk of POAF. Thus, LAVI provides a simple measure to identify patients who are in need of targeted prophylaxis for POAF.

The patient with hypertension undergoing surgery

PURPOSE OF REVIEW

General recommendations for the perioperative management of patients with hypertensive disease have not evolved much over the past 20 years, yet new pathophysiological concepts have emerged and new monitoring techniques are available today. In this review, we will discuss their significance and potential role in the modern perioperative care of hypertensive patients.

RECENT FINDINGS

For hypertensive patients, total cardiovascular risk rather than blood pressure (BP) alone should determine the preoperative strategy. Except for grade 3 hypertension, surgery should not be deferred on the basis of an elevated BP in the preoperative assessment.New data suggest that even brief hypotensive episodes during surgery may have significant impact on outcome. Isolated systolic hypertension is the predominant phenotype in elderly patients who may be particularly vulnerable to hypoperfusion in the perioperative setting.New monitoring techniques such as echocardiography and near-infrared spectroscopy may provide crucial information to optimize intraoperative control of BP based on an individual patient's pathophysiology.

SUMMARY

Hypertension is highly prevalent in patients presenting for surgery yet its impact on surgical outcome is still debated. Guidelines on risk stratification and perioperative hemodynamic management of patients with hypertensive disease remain sparse and cannot rely much on solid new evidence. Target organ damage associated with hypertensive disease rather than high BP per se appears to determine perioperative risk. In the absence of new data, an individualized and pathophysiology-based approach to control BP may be the best option to guide these patients through the perioperative period.

Emerging Concepts in Transesophageal Echocardiography

Introduced in 1977, transesophageal echocardiography (TEE) offered imaging through a new acoustic window sitting directly behind the heart, allowing improved evaluation of many cardiac conditions. Shortly thereafter, TEE was applied to the intraoperative environment, as investigators quickly recognized that continuous cardiac evaluation and monitoring during surgery, particularly cardiac operations, were now possible. Among the many applications for perioperative TEE, this review will focus on four recent advances: three-dimensional TEE imaging, continuous TEE monitoring in the intensive care unit, strain imaging, and assessment of diastolic ventricular function.