Perioperative right ventricular function and dysfunction in adult cardiac surgery-focused review (part 2-management of right ventricular failure)

Transcatheter Caval Implantation for Severe Tricuspid Regurgitation

PURPOSE OF REVIEW

We describe the evolution of caval valve implantation (CAVI) as a treatment for severe symptomatic tricuspid regurgitation (TR) in the high surgical risk patient.

RECENT FINDINGS

Surgical treatment of severe TR is often limited by the high surgical risk of the patients who tend to develop severe secondary TR. Coaptation, annuloplasty, and orthotopic replacement strategies are all limited by annular and leaflet geometry, prior valve repair, and the presence of cardiac implantable device leads. CAVI appears to be a treatment strategy for severe symptomatic TR that improves functional capacity and quality of life while also reducing edema and ascites and improving cardiac output. Chronic kidney disease is a common comorbidity of patients with severe TR; zero-contrast CAVI has been described. Severe TR is undertreated, yet common in the elderly structural heart disease population. The evolution of CAVI as a viable treatment for severe TR underscores the deleterious systemic contribution of backwards flow to morbidity and mortality. There are good safety and efficacy outcomes from registry data using the TricValve platform. Randomized controlled trials for CAVI versus medical therapy for severe TR are ongoing.

The Agreement Between Transthoracic and Transesophageal Echocardiography in the Assessment of Right Ventricular Diastolic Dysfunction Grades in Adult Patients Undergoing Cardiac Surgery: A Prospective Observational Study

Introduction The importance of right ventricular (RV) diastolic function in cardiac surgery cannot be overstated, as it significantly affects prognosis and long-term outcomes. Conventionally, RV diastolic dysfunction (RVDD) is assessed and graded using criteria from either the American Society of Echocardiography (ASE) or the British Society of Echocardiography (BSE), with measurements done by transthoracic echocardiography (TTE). However, during cardiac surgery, perioperative echocardiographic evaluation is done predominantly by transesophageal echocardiography (TEE). This study aimed to assess the agreement between TTE and TEE in grading RVDD using both ASE and BSE criteria. Methods Key two-dimensional (2D) and Doppler parameters were measured in 81 patients undergoing cardiac surgery by both TTE and TEE after anesthesia induction within 10 minutes of each other, under similar hemodynamic, anesthetic, and ventilatory conditions. RVDD gradings were done separately by TTE and TEE with both ASE and BSE criteria using the measured values of the key parameters by TTE and TEE, respectively. RVDD gradings derived from TTE were compared with those derived from TEE. The tricuspid inflow Doppler and tricuspid annular tissue Doppler parameters were measured in TEE in both mid-esophageal RV inflow-outflow (MERVIO) and deep transgastric RV inflow-outflow (DTGRVIO) views. Gradings were done separately for both views of TEE by using the Doppler values measured in the respective views (TEE-MERVIO and TEE-DTGRVIO). The TTE-derived RVDD grades were compared with those derived by both TEE-MERVIO and TEE-DTGRVIO. Weighted κ values were used to assess observed agreement beyond chance. Inter-rater reliability of the RVDD grades derived by both TTE and TEE (both views) was also checked. Individual 2D and Doppler parameters were compared between TTE and TEE in terms of Bland-Altman limits of agreement. Results As per ASE criteria, disagreement of RVDD by ≥1 grade was seen in 43 (53.1%) patients and by 2 grades in eight (9%) patients when comparing TTE and TEE-MERVIO, yielding a weighted κ of 0.14 (p=0.123). Disagreement by ≥1 grade was observed in 32 (39.5%) patients and by 2 grades in 10 (12.3%) patients when comparing TTE and TEE-DTGRVIO, yielding a weighted κ of 0.3 (p=0.002). Using the BSE Criteria, disagreement of RVDD grades occurred in nine (11.1%) patients when comparing TTE and TEE-MERVIO, yielding an unweighted κ of 0.25 (p=0.295). Disagreement occurred in 12 (14.8%) patients when comparing TTE and TEE-DTGRVIO, yielding an unweighted κ of 0.260 (p=0.187). There was almost perfect agreement between independent raters regarding both TTE- and TEE-derived RVDD grades per the ASE criteria, and substantial to almost perfect agreement per BSE criteria. Bland-Altman analysis of paired data between the TTE- and TEE-measured values of individual 2D and Doppler parameters showed wide limits of agreement. Conclusions This study revealed, at best, only fair agreement between TTE and TEE in grading RVDD. The measured 2D and Doppler echocardiographic parameters showed wide limits of agreement between TTE and TEE. We recommend further research to develop a TEE-based algorithm for grading RVDD, and to evaluate the prognostic effectiveness of perioperative TEE for predicting adverse clinical outcomes associated with RVDD.

Intraoperative prophylactic right ventricular assist device in prevention of postcardiotomy failure

OBJECTIVES

In patients at risk of developing right ventricular failure after cardiac surgery, right ventricular support with a ventricular assist device may be a promising strategy to reduce mortality. We present our experience with intraoperative right ventricular assist device implantation as a prevention strategy of right ventricular failure after cardiac surgery.

METHODS

Between 2016 and 2022, we implanted four right ventricular assist devices prophylactically in a series of patients with surgical indication for valvular heart disease and high risk of postoperative right ventricular failure. Indications for the right ventricular assist device were suprasystemic pulmonary hypertension or severe right ventricular dysfunction.

RESULTS

Externalization of the device cannulas through intercostal spaces was performed in three patients, allowing early mobilization and withdrawal without resternotomy. Removal of the device ocurred on the eighth postoperative day. ICU and hospital length of stay was 12 (±1.6) and 23 days (±4.2) respectively. Hospital mortality was null. No patient died during follow-up, mean follow-up was 32.5 months [1-72]. Patients improved their NYHA functional class up to grade II during follow-up.

CONCLUSIONS

Acute right ventricular failure after cardiac surgery remains a significant cause of morbidity and mortality. Prophylactic strategies to prevent postoperative right ventricular dysfunction may decrease the incidence of refractory postoperative right ventricular failure. We propose a novel approach to prevent right failure after cardiac surgery with prophylactic intraoperative ventricular assist device implantation.

A comprehensive overview of surgical and transcatheter therapies to treat tricuspid regurgitation in patients with heart failure

PURPOSE OF REVIEW

The unique pathophysiologic considerations of severe tricuspid regurgitation (TR) have led to advancements in surgical and transcatheter treatments. The purpose of this review is to highlight the current surgical and transcatheter tricuspid valve interventions (TTVI) to functional TR.

RECENT FINDINGS

Surgical repair with ring annuloplasty consistently demonstrates better outcomes than surgical replacement or other repair approaches. However, surgical uptake of TR correction remains relatively low, and operative mortality rates are still high owing to multiple comorbidities and advanced tricuspid valve disease/right ventricular dysfunction at time of referral. Pivotal trials for tricuspid transcatheter edge-to-edge repair (T-TEER) and transcatheter TV replacement (TTVR) indicate improved quality of life compared to medical therapy alone for high-surgical-risk patients with severe symptomatic TR. Trials are underway to assess caval valve implantation (CAVI), which holds hope for many severe TR patients who are not ideal candidates for T-TEER or orthotopic TTVR. Peri-procedural optimization of right ventricular function remains critical to promote both device success and patient outcomes.

SUMMARY

Clinical outcomes after surgical TV intervention are poor, often due to intervening late in the disease course of TR. TTVI covers a treatment gap for patients deemed inoperable or high-surgical-risk, but earlier referral for TV interventions is still important prior to patients developing multiorgan dysfunction from chronic untreated TR.

Perioperative Right Ventricular Dysfunction and Abnormalities of the Tricuspid Valve Apparatus in Patients Undergoing Cardiac Surgery

Right ventricular (RV) dysfunction frequently occurs after cardiac surgery and is linked to adverse postoperative outcomes, including mortality, reintubation, stroke, and prolonged ICU stays. While various criteria using echocardiography and hemodynamic parameters have been proposed, a consensus remains elusive. Distinctive RV anatomical features include its thin wall, which presents a triangular shape in a lateral view and a crescent shape in a cross-sectional view. Principal causes of RV dysfunction after cardiac surgery encompass ischemic reperfusion injury, prolonged ischemic time, choice of cardioplegia and its administration, cardiopulmonary bypass weaning characteristics, and preoperative risk factors. Post-left ventricular assist device (LVAD) implantation RV dysfunction is common but often transient, with a favorable prognosis upon resolution. There is an ongoing debate regarding the benefits of concomitant surgical repair of the RV in the presence of regurgitation. According to the literature, the gold standard techniques for assessing RV function are cardiac magnetic resonance imaging and hemodynamic assessment using thermodilution. Echocardiography is widely favored for perioperative RV function evaluation due to its accessibility, reproducibility, non-invasiveness, and cost-effectiveness. Although other techniques exist for RV function assessment, they are less common in clinical practice. Clinical management strategies focus on early detection and include intravenous drugs (inotropes and vasodilators), inhalation drugs (pulmonary vasodilators), ventilator strategies, volume management, and mechanical support. Bridging research gaps in this field is crucial to improving clinical outcomes associated with RV dysfunction in the near future.

Harlequin effect and central veno-arterial extracorporeal life support

"Harlequin effect" may be observed in the watershed region of a patient with pulmonary dysfunction, receiving peripheral veno-arterial extracorporeal membrane oxygenation via the femoral vessels. In such cases, retrograde oxygenated blood from the peripheral inflow cannula converges with the antegrade deoxygenated blood ejected from the left ventricle. This occurs when the left ventricle is ejecting significantly but the recovery of pulmonary function lags behind. Herein, we describe the occurrence of "Harlequin effect" in the setting of central veno-arterial extracorporeal membrane oxygenation that ensues due to the persistence of right ventricular dysfunction in the presence of an interatrial communication. This results in right to left shunting at the atrial level while weaning the patient from extracorporeal life support.