Preoperative predictors of late postoperative outcome among patients with nonischemic mitral regurgitation with 'high risk' descriptors and comparison with unoperated patients

Association between pre-operative right ventricular impairment on transthoracic echocardiography and outcomes after conventional and minimally invasive mitral valve surgery

BACKGROUND

Right ventricular (RV) impairment may have prognostic value in patients undergoing mitral valve surgery. It is unclear whether RV dysfunction predicts long-term mortality, especially in the era of minimally invasive mitral surgery.

METHODS

We performed a retrospective analysis of consecutive patients referred for conventional (via sternotomy) and minimally invasive mitral valve surgery (MIMVS) between 01 January 2013 and 29 August 2018 in a tertiary cardiac centre. We truncated follow-up times at 25 March 2020. RV impairment was defined by reduced RV longitudinal function (TAPSE <17 mm) and/or dilated basal RV diameter (RVD1 > 42 mm). Primary outcome was all-cause mortality.

RESULTS

The study cohort included 359 patients followed up for a median period of 4.2 (1.8) years. MIMVS approach was performed in 127 (35.4%) and conventional approach in 232 (64.6%) patients of whom 36 (28%) and 45 (19%), respectively, had RV impairment. EuroSCORE II was significantly higher in patients with RV impairment compared with patients with preserved RV function, irrespective of the surgical approach. Consequently, in both groups, patients with RV impairment had significantly higher mortality compared to patients with preserved RV function. RV impairment adjusted for EuroSCORE II predicted mortality in the whole cohort (HR 2.139, 95% CI 1.249-3.663) and in conventional approach (HR 2.361, 95% CI 1.249-4.465) in contrast to MIMVS (HR 1.570, 95% CI 0.493-4.997).

CONCLUSION

In this real world cohort, patients with RV impairment and/or dilation had reduced long-term survival following both conventional surgery and MIMVS. Patients should be referred to surgery prior to worsening of RV function.

Right Ventricular Dysfunction and Short-Term Outcomes Following Left-Sided Valvular Surgery: An Echocardiographic Study

Background The prognostic value of echocardiographic evaluation of right ventricular (RV) function in patients undergoing left-sided valvular surgery has not been well described. The objective of this study is to determine the role of broad echocardiographic assessment of RV function in predicting short-term outcomes after valvular surgery. Methods and Results Preoperative echocardiographic data, perioperative adverse outcomes, and 30-day mortality were analyzed in patients who underwent left-sided valvular surgery from 2006 to 2014. Echocardiographic parameters used to evaluate RV function include RV fractional area change, tricuspid annular plane systolic excursion, systolic movement of the RV lateral wall using tissue Doppler imaging (S'), RV myocardial performance index, and RV dP/dt. Subjects with at least 3 abnormal parameters out of the 5 aforementioned indices were defined as having significant RV dysfunction. The study included 269 patients with valvular surgery (average age: 67±15, 60.6% male, 148 aortic, and 121 mitral). RV dysfunction was found in 53 (19.7%) patients; 30-day mortality occurred in 20 patients (7.5%). Compared with normal RV function, patients with RV dysfunction had higher 30-day mortality (22.6% versus 3.8%; P=0.01) and were at risk for developing multisystem failure/shock (13.2% versus 3.2%; P=0.01). Multivariate analyses showed that preexisting RV dysfunction was the strongest predictor of increased 30-day mortality (odds ratio: 3.5; 95% CI, 1.1-11.1; P<0.05). Conclusions Preoperative RV dysfunction identified by comprehensive echocardiographic assessment is a strong predictor of adverse outcomes following left-sided valvular surgery.

Perioperative Right Ventricular Dysfunction: Analysis of Outcomes

Right ventricular dysfunction (RVD) is a well-known prognostic factor for adverse outcomes in cardiovascular medicine. The right ventricle (RV) in medically managed heart failure patients and in surgical patients perioperatively generally is overshadowed by left ventricular disease. However, with advancement of various diagnostic tools and better understanding of its functional anatomy, the role of the RV is emerging in many clinical conditions. The failure of one ventricle has significant effect on the function of the other ventricle and it is predominantly due to ventricular interdependence.¹ The etiology of RVD is multifactorial and irrespective of etiology. RVD has been associated with significant increases in morbidity and mortality in various clinical scenarios.^2,3 The primary objective of this comprehensive review is to analyze various etiology-related outcomes of RVD in the perioperative population.

Comparison of Right Ventricular Function Between Three-Dimensional Transesophageal Echocardiography and Pulmonary Artery Catheter

OBJECTIVE

This study aimed to compare measurements of right ventricular function using three-dimensional transesophageal echocardiography (3D TEE), and pulmonary artery catheters (PACs) in patients undergoing cardiac surgery. The authors examined the practicality of using the 3D TEE.

DESIGN

Prospective observational.

SETTING

Cardiac operating room at a single university hospital.

PARTICIPANTS

All adult patients undergoing elective cardiac surgery at a single tertiary care university hospital over two years.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), stroke volume (SV), and right ventricular ejection fraction (RVEF) were measured with both 3D TEE and PACs. Assessments were performed using correlation coefficients, paired t tests, and Bland-Altman plots. Thirty-one patients participated in this study. Each measurement showed good agreement. RVEDV and RVESV were slightly lower on 3D TEE than on PAC (205.9 mL v 220.2 mL, p = 0.0018; 143.0 mL v 155.5 mL, p = 0.0143, respectively), whereas no significant differences were observed for SV and RVEF (31.0% v 31.1%, p = 0.0569; 61.6 mL v 66.9 mL, p = 0.92, respectively). Linear regression analysis showed high correlation between 3D TEE and PAC for RVEDV (r = 0.87) and RVESV (r = 0.81), and moderate correlation for SV (r = 0.67) and RVEF (r = 0.67). In the Bland-Altman plot, most patients were within the 95% limits of the agreement throughout all measurements.

CONCLUSION

A high correlation was found between measurements made with a PAC and with 3D TEE in the assessment of right ventricular function. Three-dimensional TEE would be a potential alternative to PAC for assessment of right ventricular function during intraoperative periods.

Prognostic Assessment of Right Ventricular Systolic Dysfunction on Post-Transcatheter Aortic Valve Replacement Short-Term Outcomes: Systematic Review and Meta-Analysis

Background Right ventricular systolic dysfunction (RVSD) is a known risk factor for adverse outcome in surgical aortic valve replacement. Transcatheter aortic valve replacement (TAVR), on the other hand, has been shown to be either beneficial or have no effect on right ventricular systolic function. However, the prognostic significance of RVSD on TAVR has not been clearly determined. We conducted a systematic review and meta-analysis to define the impact of RVSD on outcomes in terms of 1-year mortality in patients with severe aortic stenosis undergoing TAVR. Methods and Results An extensive literature review was performed, with an aim to identify clinical studies that focused on the prognosis and short-term mortality of patients with severe symptomatic aortic stenosis who underwent TAVR. A total of 3166 patients from 8 selected studies were included. RVSD, as assessed with tricuspid annular plane systolic excursion, fractional area change or ejection fraction, was found to be a predictor of adverse procedural outcome after TAVR (hazard ratio, 1.31; 95% CI, 1.1-1.55; P=0.002). Overall, we found that RVSD did affect post-TAVR prognosis in 1-year mortality rate. Conclusions Patients with severe, symptomatic aortic stenosis and concomitant severe RVSD have a poor 1-year post-TAVR prognosis when compared with patients without RVSD. Right ventricular dilation and severe tricuspid regurgitation were associated with increased 1-year morality post-TAVR and should be considered as independent risk factors. Further evaluations of long-term morbidity, mortality, as well as sustained improvement in functional class and symptoms need to be conducted to determine the long-term effects.

Impaired right ventricular ejection fraction after cardiac surgery is associated with a complicated ICU stay

Background

Right ventricular (RV) dysfunction is a known risk factor for increased mortality in cardiac surgery. However, the association between RV performance and ICU morbidity is largely unknown.

Methods

We performed a single-centre, retrospective study including cardiac surgery patients equipped with a pulmonary artery catheter, enabling continuous right ventricular ejection fraction (RVEF) measurements. Primary endpoint of our study was ICU morbidity (as determined by ICU length of stay, duration of mechanical ventilation, usage of inotropic drugs and fluids, and kidney dysfunction) in relation to RVEF. Patients were divided into three groups according to their RVEF; < 20%, 20-30%, and > 30%.

Results

We included 1109 patients. Patients with a RVEF < 20% had a significantly longer stay in ICU, a longer duration of mechanical ventilation, higher fluid balance, a higher incidence of inotropic drug usage, and more increase in postoperative creatinine levels in comparison to the other subgroups. In a multivariate analysis, RVEF was independently associated with increased ICU length of stay (OR 0.934 CI 0.908-0.961, p < 0.001), prolonged duration of mechanical ventilation (OR 0.969, CI 0.942-0.998, p = 0.033), usage of inotropic drugs (OR 0.944, CI 0.917-0.971, p < 0.001), and increase in creatinine (OR 0.962, CI 0.934-0.991, p = 0.011).

Conclusions

A decreased RVEF is independently associated with a complicated ICU stay.

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.

A Comparison of Left- and Right-Sided Strain Software for the Assessment of Intraoperative Right Ventricular Function

OBJECTIVE

To compare intraoperative right ventricular (RV) strain measurements made with left ventricular (LV) strain software commonly found on the echocardiography machine (Philips QLAB chamber motion quantification, version 10.7, Philips, Amsterdam, The Netherlands), with offline analysis using the dedicated RV strain software (EchoInsight, version 2.2.6.2230, Epsilon Imaging, Ann Arbor, MI).

DESIGN

Prospective, nonrandomized, observational study.

SETTING

Single tertiary level, university-affiliated hospital.

PARTICIPANTS

The study comprised 48 patients undergoing transesophageal echocardiography for cardiac or noncardiac surgery.

INTERVENTIONS

Two-dimensional (2D) and 3-dimensional (3D) images of the right ventricle were obtained. Intraoperative 2D images were analyzed in real time for RV free wall strain (FWS) and global longitudinal strain (GLS) using QLAB chamber motion quantification (CMQ) LV strain software on the echocardiography machine. Two dimensional images were then analyzed offline to determine the RV FWS and GLS using EchoInsight RV-specific strain software. Three-dimensional images were then analyzed offline to detemine the 3D RV ejection fraction (3D RV EF) using TomTec 4D RV function (Unterschleissheim, Germany). Spearman's correlation and Bland-Altman analyses were used to characterize the relationship between RV strain measurements. Both types of strain measurements were compared to a reference standard of 3D RV EF.

MEASUREMENTS AND MAIN RESULTS

Intraoperative RV strain measurements using LV-specific strain software correlated with offline RV strain measurements using the RV-specific strain software (FWS rho = 0.85; GLS rho = 0.81). The bias and limits of agreement were 0.75% (- 6.66 to 8.17) for FWS and -4.53% (-11.55 to 2.50) for GLS. The sensitivity and specificity for RV dysfunction for the intraoperative LV-specific software were 94% (95% confidence interval [CI] 73-100) and 70% (95% CI 51-85), respectively, for RV FWS and 94% (95% CI 73-100) and 67% (95% CI 47-83), respectively, for RV GLS. The sensitivity and specificity for RV dysfunction for the offline RV-specific software were 89% (95% CI 65-99) and 73% (95% CI 54-88), respectively, for RV FWS and 94% (95% CI 73-100) and 30% (95% CI 15-49), respectively, for RV GLS.

CONCLUSION

Intraoperative RV strain measurements using LV-specific strain software commonly available on the echocardiography machine (QLAB CMQ) correlate with offline RV strain measurements using RV-specific strain software (EchoInsight). The bias and limits of agreement for these left- and right-sided strain software suggest that these 2 measures of RV function cannot be used interchangeably. Both, however, were sensitive measures of RV dysfunction and therefore are likely clinically relevant.

The Sum of Early Diastolic Annulus Velocities in the Mitral and Tricuspid Valve Can Predict Adverse Events After Cardiac Surgery

OBJECTIVES

To assess whether a tissue Doppler imaging (TDI)-based parameter consisting of the sum of early diastolic velocities of the mitral annulus (Me') and tricuspid annulus (Te') can serve as a predictor of adverse outcomes after cardiac surgery.

DESIGN

Prospective, observational study.

SETTING

University hospital.

PARTICIPANTS

The study comprised 100 patients undergoing cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

After anesthetic induction, transesophageal echocardiography was performed to obtain the values of the early transmitral flow velocity (E), Me', and Te'. The primary endpoint was the incidence of postoperative major organ morbidity and mortality (MOMM) events, including death, redo surgery, prolonged ventilation, stroke, sternal infection, and dialysis. Receiver operating characteristic and multivariate logistic analyses were used to examine the prognostic performance of TDI-based parameters for predicting MOMM incidence. The secondary endpoint was the incidence of death or rehospitalization for cardiovascular disease within 1 year post-discharge. TDI-based parameters were measured in 87 of the 100 patients enrolled. Me' plus Te' had better prognostic ability (area under the curve 0.771; threshold 13 cm/s; sensitivity 86.7%; specificity 64.9%) than that of Me' or E to Me' (E/Me')% and was an independent predictor of MOMM (odds ratio 0.45; 95% confidence interval 0.28-0.74, p = 0.001), whereas Me' was not. Lower Me' plus Te' (≤13 cm/s) was associated with a significantly higher incidence and earlier onset of cardiovascular events within 1 year post-discharge (p = 0.012).

CONCLUSIONS

Compared with Me' and E/Me', which traditionally are used for assessing diastolic function, Me' plus Te' showed better prognostic ability for both short- and long-term outcomes of cardiac surgery.

Impact and evolution of right ventricular dysfunction after successful MitraClip implantation in patients with functional mitral regurgitation

BACKGROUND

Right ventricular dysfunction (RVdysf) is a predictor of poor outcome in patients with heart failure and valvular disease. The aim of this study was to evaluate the evolution and the impact of RVdysf in patients with moderate-severe functional mitral regurgitation (FMR) successfully treated with MitraClip.

METHODS AND RESULTS

From October 2008 to July 2014, 60 consecutive high surgical risk FMR patients were evaluated and stratified into two groups: RVdysf group (TAPSE < 16 mm and/or S'TDI < 10 cm/s, 21 patients) and No-RVdysf group (38 patients). The overall mean age of patients was 73 ± 8 (83% male). Ischemic FMR etiology was present in 67%. Mean LVEF was 30 ± 10%. Overall mean time follow-up was 565 ± 310 days. The only significant difference between the two groups was a greater prevalence of stroke, ICD and use of aldosterone antagonist in RVdysf group. Acute procedural success was achieved in 90% of patients. At 6-month echo-matched analysis significant RV function improvement was observed in patients with baseline RVdysf (TAPSE 15 ± 3.0 vs. 19 ± 4.5, p = 0.007; S'TDI 7 ± 1.2 vs. 11 ± 2.8, p < 0.0001; baseline vs. 6-month, respectively). The mean improvement in the 6-min walking test was significant in both groups (120 and 143 m, RVdysf and No-RVdysf groups, respectively). At Kaplan-Meier analysis, the presence of RVdysf did not affect the outcome in terms of freedom from composite efficacy endpoint.

CONCLUSIONS

This study shows that successful MitraClip implantation in patients with FMR and concomitant right ventricular dysfunction yields significant improvement of RV function at mid-term follow-up. Further data on larger population will be required to confirm our observations.

The Role of Right Ventricular Function in Mitral Valve Surgery

<p><b>Background:</b> An impaired right ventricular function is associated with a poor survival rate in patients with heart failure. Few investigations have analyzed the prognostic value of right ventricular function on the outcomes of mitral valve (MV) surgery. The objectives of this study were to define the effect of right ventricular function on postoperative outcomes after MV repair (MVP) or replacement (MVR).</p><p><b>Methods:</b> From September 2007 to February 2012, 335 consecutive patients underwent MVP or MVR at our institution. Preoperative transthoracic and transesophageal echocardiography (TEE) and postoperative TEE were used to define right ventricular function and MV performance. Preoperative right ventricular function was graded as normal to mild (grade 1-2) or as moderate to severe (grade 3-4). MV or tricuspid valve regurgitation was graded as non-trivial to mild (grade 0-2) or as moderate to severe (grade 3-4) preoperatively and postoperatively. Survival rate was evaluated at 1 year after surgery.</p><p><b>Results:</b> Of the 334 patients in the study, 280 patients showed a normal to a mildly impaired right ventricular function preoperatively (group 1). Fifty-four patients presented with moderate to severe right ventricular dysfunction (group 2). Patients with a compromised right ventricular function were more likely to undergo MVR (28.6% versus 53.7%, <i>P</i> <.001). The mean pulmonary artery pressure was 23.6 mm Hg in group 1 and 34 mm Hg in group 2 (<i>P</i> <.001). The left atrial diameter was 4.6 cm in group 1 and 5.3 cm in group 2 (<i>P</i> <.001). The 2 groups were not different with respect to operative mortality, but the patients in group 2 experienced more transfusion of blood products (588.4 mL versus 1180.6 mL, <i>P</i> <.001), longer intensive care unit stays (83.9 versus 149.6 hours, <i>P</i> <.001), and hospital stays (8.9 versus 12.8 days, <i>P</i> = .005). The rate of postoperative MV regurgitation was significantly higher in group 2 (1.8 versus 14.8%, <i>P</i> <.001). The overall 1-year survival rate was 92.5% in group 1 and 94.5% in group 2 (<i>P</i> = .59).</p><p><b>Conclusions:</b> This study has shown that a dysfunctional preoperative right ventricular function uses more resources and is associated with postoperative MV regurgitation, but it is not associated short- and mid-term mortality after MV surgery.</p>

Usefulness of preoperative exercise tolerance to predict late survival and symptom persistence after surgery for chronic nonischemic mitral regurgitation

Exercise duration during exercise treadmill testing (ETT) predicts long-term outcome among asymptomatic patients with mitral regurgitation. However, the prognostic value of preoperative exercise duration in patients who undergo mitral valve surgery is unknown. We examined findings among 45 prospectively followed (average 9.2 ± 4.3 years) patients (aged 54.8 ± 12.0 years, 45% men) with chronic isolated severe MR who underwent ETT before mitral valve surgery to test the hypotheses that exercise duration predicts long-term postoperative survival and persistent symptoms within 2 years after operation. During follow-up, 11 patients died; of these, 8 had persistent symptoms. Among patients who exercised >7 minutes, average annual postoperative all-cause and cardiovascular mortality risks were 0.75% (both endpoints) versus 5.4% and 4.8%, respectively, versus those who exercised ≤7 minutes (p = 0.003 all-cause, p = 0.007 cardiovascular). Exercise duration predicted postoperative deaths (p <.02 all cause, p <.04 cardiovascular) even when analysis was adjusted for preoperative variations in age, gender, medications, history of atrial fibrillation, and peak exercise heart rates. Other ETT, echocardiographic, and clinical variables were not independently associated with these outcomes when exercise duration was considered in the analysis. Preoperative exercise duration also predicted postoperative (New York Heart Association functional class ≥II) symptom persistence (p = 0.012), whereas other ETT, echocardiographic and clinical variables did not (NS, all). In conclusion, among patients who undergo surgery for chronic nonischemic mitral regurgitation, preoperative exercise duration, unlike many commonly used descriptors, is useful for predicting postoperative mortality and symptom persistence. Future research should determine whether interventions to improve exercise tolerance before mitral valve surgery can modify these postoperative outcomes.

Nonischemic mitral regurgitation: prognostic value of nonsustained ventricular tachycardia after mitral valve surgery

BACKGROUND

Nonsustained ventricular tachycardia (VT), frequent in unoperated severe mitral regurgitation (MR), confers mortality risk [sudden death (SD) and cardiac death (CD)]. The prognostic value of VT after mitral valve surgery (MVS) is unknown; we aimed to define this prognostic value and to assess its modulation by left (LV) and/or right (RV) ventricular ejection fraction (EF) for mortality after MVS.

METHODS

In 57 patients (53% females, aged 58 ± 12 years) with severe MR prospectively followed before and after MVS, we performed 24-hour ambulatory electrocardiograms approximately annually. LVEF and RVEF were determined within 1 year after MVS by radionuclide cineangiography.

RESULTS

During 9.52 ± 3.49 endpoint-free follow-up years, late postoperative CD occurred in 11 patients (7 SD, 4 heart failures). In univariable analysis, >1 VT episode after MVS predicted SD (p < 0.01) and CD (SD or heart failure; p < 0.04). Subnormal postoperative RVEF predicted CD (p < 0.04). When adjusted for preoperative age, gender, etiology or antiarrhythmics, both postoperative VT and RVEF predicted CD (p ≤ 0.05). When postoperative VT and RVEF were both in the multivariable model, only subnormal RVEF predicted CD (p < 0.04). Among those with normal RVEF, VT >1 episode predicted SD (p = 0.03).

CONCLUSION

Postoperative VT and subnormal RVEF predict late postoperative deaths in nonischemic MR. Their assessment may aid patient management.

Right ventricular plasticity and functional imaging

Right ventricular (RV) function is a strong independent predictor of outcome in a number of distinct cardiopulmonary diseases. The RV has a remarkable ability to sustain damage and recover function which may be related to unique anatomic, physiologic, and genetic factors that differentiate it from the left ventricle. This capacity has been described in patients with RV myocardial infarction, pulmonary arterial hypertension, and chronic thromboembolic disease as well as post-lung transplant and post-left ventricular assist device implantation. Various echocardiographic and magnetic resonance imaging parameters of RV function contribute to the clinical assessment and predict outcomes in these patients; however, limitations remain with these techniques. Early diagnosis of RV function and better insight into the mechanisms of RV recovery could improve patient outcomes. Further refinement of established and emerging imaging techniques is necessary to aid subclinical diagnosis and inform treatment decisions.

Right heart on multidetector CT

Right ventricular function plays an integral role in the pathogenesis and outcome of many cardiovascular diseases. Imaging the right ventricle has long been a challenge because of its complex geometry. In recent years there has been a tremendous expansion in multidetector row CT (MDCT) and its cardiac applications. By judicious modification of contrast medium protocol, it is possible to achieve good opacification of the right-sided cardiac chambers, thereby paving the way for exploring the overshadowed right heart. This article will describe the key features of right heart anatomy, review MDCT acquisition techniques, elaborate the various morphological and functional information that can be obtained, and illustrate some important clinical conditions associated with an abnormal right heart.

Pulmonary hypertension in cardiac surgery

Pulmonary hypertension is an important prognostic factor in cardiac surgery associated with increased morbidity and mortality. With the aging population and the associated increase severity of illness, the prevalence of pulmonary hypertension in cardiac surgical patients will increase. In this review, the definition of pulmonary hypertension, the mechanisms and its relationship to right ventricular dysfunction will be presented. Finally, pharmacological and non-pharmacological therapeutic and preventive approaches will be presented.

Temporary Right Ventricular Support with Impella Recover RD Axial Flow Pump

Post-cardiotomyright ventricular failure is a serious complication that frequently results in adverse outcomes. We reviewed our experience with the Impella Recover RD (Impella Cardiosystems GMbH, Aachen, Germany). From January 2007 to December 2007, 7 patients (5 males, 54 + 7 years old) had this device implanted for temporary support after heart transplantation in 4, after repeat mitral valve replacement in 2, and with a left ventricular assist device in 1. Devices were implanted during initial operation ( n = 5) or shortly thereafter ( n = 2). Six patients underwent implantation without cardiopulmonary bypass. Effective support with pump flows of 4.0-4.5 L · min−1 and adequate unloading (central venous pressure decreased from 15.3 ± 1.4 to 9.4 ± 1.2 mm Hg) was achieved in all patients. Patients were assisted for a mean duration of 4.9 ± 4.5 days. Three patients could be weaned after 7.0 ± 5.6 days of support and underwent device explantation without cardiopulmonary bypass. One of these patients died of recurrent right ventricular failure, 2 remained stable but died later of sepsis. The patient with a left ventricular assist device was switched to an alternative device for prolonged support. Two patients experienced pump dysfunction. Our preliminary experience shows that the Impella Recover RD is an effective device that can be easily implanted and explanted. However, its mechanical reliability needs to be improved.

The right ventricle in cardiac surgery, a perioperative perspective: II. Pathophysiology, clinical importance, and management

The importance of right ventricular (RV) function in cardiovascular disease and cardiac surgery has been recognized for several years. RV dysfunction has been shown to be a significant prognostic factor in cardiac surgery and heart transplantation. In the first article of this review, key features of RV anatomy, physiology, and assessment were presented. In this second part, we review the pathophysiology, clinical importance, and management of RV failure in cardiac surgery.

Right ventricular myocardial performance index predicts perioperative mortality or circulatory failure in high-risk valvular surgery

BACKGROUND

The prognostic value of right ventricular myocardial performance index (RVMPI) and right ventricular fractional area change (RVFAC) in mitral or aortic valve surgery has not been well described. The main objective of this study is to assess the prognostic value of RVMPI and RVFAC in predicting postoperative mortality or circulatory failure.

METHODS

RVMPI and RVFAC were prospectively measured after induction of anesthesia using transesophageal echocardiography in 50 consecutive patients undergoing corrective mitral or aortic valve surgery. Univariate and multivariate analyses were performed for the primary clinical end point of in-hospital mortality or circulatory failure.

RESULTS

In the study population, the mean age was 67 +/- 9 years. The primary end point occurred in 17 patients (34%); three patients died, and 14 patients presented signs of circulatory failure. Multivariate regression analysis identified RVMPI and RVFAC as variables of prognostic significance.

CONCLUSION

Preoperative RVMPI and RVFAC could have an incremental value in predicting postoperative mortality and morbidity in valvular heart surgery. Future studies are needed to validate these results in a larger population.

Mitral regurgitation: Current treatment options and their selection

Mitral regurgitation (MR) is a mechanically complex hemodynamic abnormality of various etiologies that, if untreated, leads to myocardial dysfunction, heart failure, and sudden death. Unless hemodynamically severe, MR is not a major risk factor for debility and death. However, even more modest MR may impact on longevity and may create risk for thromboembolic and infectious sequelae. Currently, therapy for severe MR is surgical valve replacement or repair. When MR is not secondary to ischemic sequelae, generally accepted indications for surgery include any symptoms, left ventricular or right ventricular dysfunction or left ventricular geometric variations that reach defined levels of prognostic concern, or development of atrial fibrillation. However, low perioperative risk of repair causes some to urge surgery for severe MR irrespective of other findings. Similar controversy confounds decisions about mitral valve surgery during coronary artery bypass grafting when MR is a sequel of ischemic disease. Drug treatment has not altered MR outcome, although drugs can mitigate symptoms if surgery is contraindicated by intercurrent disease. There is no basis for prophylactic drug treatment to preserve myocardial function in asymptomatic patients.

Selecting patients with mitral regurgitation and left ventricular dysfunction for isolated mitral valve surgery

BACKGROUND

American College of Cardiology/American Heart Association (ACC/AHA) Guidelines state that patients with an ejection fraction (EF) of 30% or less should not undergo mitral valve replacement for mitral regurgitation (MR). We sought to establish, using a national cardiac surgery database, whether patients with left ventricular dysfunction may safely undergo mitral valve surgery for MR, and if so, which ones.

METHODS

We queried the Society of Thoracic Surgeons (STS) National Database to identify patients who had isolated mitral valve replacement or repair for MR between 1998 and 2001. Mortality and morbidity outcomes were compared by EF category (< or = 30% vs > 30%), and observed mortality compared by EF group, stratified by predicted risk for mortality. A classification and regression tree (CART) model was then used to determine which patient characteristics contributed most to designate the high-risk patient.

RESULTS

Of the 14,582 patients who had mitral valve surgery, 727 had an EF of 30% or less and 13,855 had an EF of more than 30%. Observed mortality rates were higher for patients with an EF of 30% or less (5.4% vs 3.1%). However, for low-risk to medium-risk patients, mortality rates remained fairly constant across levels of EF. Mortality is notably increased in the high-risk patients (predicted risk > 10%). A classification tree identifies three key characteristics for high risk: age more than 75 years, renal failure, and emergent or salvage procedure.

CONCLUSIONS

When the predicted mortality risk is less than 10%, EF has minimal impact on operative mortality for mitral regurgitation. In contrast to the ACC/AHA Guidelines, our data show that operative risk for mitral valve surgery is not prohibitive for most patients with ventricular dysfunction.

Mitral Valve Repair in Patients With Low Left Ventricular Ejection Fractions

STUDY OBJECTIVES

This retrospective study was performed to examine the outcome of mitral valve repair (ie, mitral valvuloplasty [MVP]) in relation to preoperative low left ventricular ejection fraction (LVEF).

DESIGN AND SETTINGS

From our series of 338 consecutive patients who underwent MVP between 1983 and 2001, we compared the course of 302 patients with preoperative LVEF of > 35% (group I) to that of 36 patients with LVEF of </= 35% (group II).

RESULTS

Preoperatively, group II patients were more likely to be associated with ischemic heart disease (IHD) [p < 0.0002], and to have undergone emergency surgery (p < 0.02) and concomitant coronary artery bypass graft surgery (CABG) [p < 0.02]. The perioperative mortality rate was 8% for group II and 2% for group I (p < 0.03). On multivariate analysis, predictors of increased operative mortality were emergent operation (p < 0.001) and preoperative New York Heart Association (NYHA) class IV (p < 0.02). Predictors of overall mortality (early and late) included emergency operation (p < 0.02), preoperative NYHA class IV (p < 0.002), and IHD (p < 0.0001). Postoperatively, 78% of patients from both groups were in NYHA class I/II. The 5-year rate of freedom from reoperation was 89%. The estimated overall 5-year survival rate (early and late) was 82% for group I and 54% for group II (p < 0.02), and when associated with prior CABG, prior myocardial infarction, or concomitant CABG, it was 0%, 37%, and 63%, respectively, in group II.

CONCLUSIONS

Good symptomatic relief and acceptable overall survival can be obtained in patients in both groups after they have undergone MVP, in the absence of serious comorbidities. Preoperative NYHA class IV and end-stage IHD increase early and late mortality, particularly in group II patients, in whom surgery may be a salvage effort only. Prognosis is dismal in group II patients who have previously undergone CABG. In chronic cases, an early referral for MVP electively before deterioration to end-stage heart disease would improve survival even in patients with low LVEF.

Native mitral valve regurgitation. Proactive management can improve outlook

Mitral regurgitation is a common valvular abnormality that can result in substantial morbidity. Primary care physicians should maintain a high index of suspicion for this disorder, especially in patients with symptoms of heart failure. The paramount concern is early identification of patients with mitral regurgitation and prompt referral to a cardiologist when symptoms occur or if evidence of ventricular enlargement or reduction in ejection fraction is found. Echocardiography is an invaluable tool in determining the severity of regurgitation, the integrity of the mitral valve apparatus, the extent of left ventricular enlargement, and the ejection fraction. Although no standard medical treatment has been established for mitral regurgitation, use of ACE inhibitors is appropriate. Patients presenting with severe, acute mitral regurgitation from papillary muscle rupture should be evaluated for ischemia and treated expediently. The preferred operative procedure in patients with severe mitral regurgitation and left ventricular dysfunction is mitral valve repair, if possible, or mitral valve replacement with posterior chordal preservation, if feasible.