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.

Intraoperative Assessment of Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing Aortic Valve Replacement.

OBJECTIVE: Evaluation of noninvasive left ventricular (LV) myocardial work (MW) enables insights into cardiac contractility and efficacy beyond conventional echocardiography. However, there is limited intraoperative data on patients undergoing surgical aortic valve replacement (AVR). The aim of this study was to describe the feasibility and the intraoperative course of this technique of ventricular function assessment in these patients and compare it to conventional two (2D)- and three-dimensional (3D) echocardiographic measurements and strain analysis. DESIGN: Prospective observational study. SETTING: Single university hospital. PARTICIPANTS: Twenty-five patients scheduled for isolated AVR with preoperative preserved left and right ventricular function, sinus rhythm, without significant other heart valve disease or pulmonary hypertension, and an uneventful intraoperative course. INTERVENTIONS: Transesophageal echocardiography was performed after induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). Evaluation was performed in stable hemodynamics, in sinus rhythm or atrial pacing and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: EchoPAC v206 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). Estimation of myocardial work was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF, GWI and GCW decreased significantly after AVR (T1 v T2, 1,647 ± 380 mmHg% v 1,021 ± 233 mmHg%, p < 0.001; T1 v T2, 2,095 ± 433 mmHg% v 1,402 ± 242 mmHg%, p < 0.001, respectively), while GWW remained unchanged (T1 v T2, 296 mmHg% [IQR 178-452) v 309 mmHg% [IQR 255-438), p = 0.97). This resulted in a decreased GWE directly after bypass (T1 v T2, 84% ± 6% v 78% ± 5%, p < 0.001), but GWE already improved at the end of surgery (T2 v T3, 78% ± 5% v 81% ± 5%, p = 0.003). There was no significant change in the values of GWI, GCW, or 2D and 3D LVEF before and after sternal closure (T2 v T3). CONCLUSION: LV MW analysis showed a reduction of LV workload after bypass in our group of patients, which was not detected by conventional echocardiographic measures. This evolving technique provides deeper insights into cardiac energetics and efficiency in the perioperative course of aortic valve replacement surgery.

Impact of pulmonary hypertension on short-term outcomes in patients undergoing surgical aortic valve replacement for severe aortic valve stenosis.

OBJECTIVES: In patients with left heart disease and severe aortic stenosis (AS), pulmonary hypertension (PH) is a common comorbidity and predictor of poor prognosis. Untreated AS aggravates PH leading to an increased right ventricular afterload and, in line to right ventricular dysfunction. The surgical benefit of aortic valve replacement (AVR) in elderly patients with severe AS and PH could be limited due to the multiple comorbidities and poor outcomes. Therefore, we purposed to investigate the impact of PH on short-term outcomes in patients with moderate to severe AS who underwent surgical AVR in our heart center. METHODS: In this study we retrospectively analyzed a cohort of 99 patients with severe secondary post-capillary PH who underwent surgical AVR (AVR + PH group) at our heart center between 2010 and 2021 with a regard to perioperative outcomes. In order to investigate the impact of PH on short-term outcomes, the control group of 99 patients without pulmonary hypertension who underwent surgical AVR (AVR group) at our heart center with similar risk profile was accordingly analyzed regarding pre-, intra- and postoperative data. RESULTS: Atrial fibrillation occurred significantly more often (p = .013) in patients who suffered from PH undergoing AVR. In addition, the risk for cardiac surgery (EUROSCORE II) was significantly higher (p < .001) in the above-mentioned group. Likewise, cardiopulmonary bypass time (p = .018), aortic cross-clamp time (p = .008) and average operation time (p = .009) were significantly longer in the AVR + PH group. Furthermore, the in-hospital survival rate was significantly higher (p = .044) in the AVR group compared to the AVR + PH group. Moreover, the dialysis rate was significantly higher (p < .001) postoperatively in patients who suffered PH compared to the patients without PH undergoing AVR. CONCLUSION: In our study, patients with severe PH and severe symptomatic AS who underwent surgical aortic valve replacement showed adverse short-term outcomes compared to patients without PH.

Surgical versus Interventional Treatment of Concomitant Aortic Valve Stenosis and Coronary Artery Disease.

BACKGROUND: Coronary artery disease (CAD) is frequently diagnosed in patients with aortic valve stenosis. Treatment options include surgical and interventional approaches. We therefore analyzed short-term outcomes of patients undergoing either coronary artery bypass grafting with simultaneous aortic valve replacement (CABG + AVR) or staged percutaneous coronary intervention and transcatheter aortic valve implantation (PCI + TAVI). METHODS: From all patients treated since 2017, we retrospectively identified 237 patients undergoing TAVI within 6 months after PCI and 241 patients undergoing combined CABG + AVR surgery. Propensity score matching was performed, resulting in 101 matched pairs. RESULTS: Patients in the CABG + AVR group were younger compared with patients in the PCI + TAVI group (71.9 ± 4.9 vs 81.4 ± 3.6 years; p < 0.001). The overall mortality at 30 days before matching was higher after CABG + AVR than after PCI + TAVI (7.8 vs 2.1%; p = 0.012). The paired cohort was balanced for both groups regarding demographic variables and the risk profile (age: 77.2 ± 3.7 vs78.5 ± 2.7 years; p = 0.141) and EuroSCORE II (6.2 vs 7.6%; p = 0.297). At 30 days, mortality was 4.9% in the CABG + AVR group and 1.0% in the PCI + TAVI group (p = 0.099). Rethoracotomy was necessary in 7.9% in the CABG + AVR, while conversion to open heart surgery was necessary in 2% in the PCI + TAVI group. The need for new pacemaker was lower after CABG + AVR than after PCI + TAVI (4.1 vs 6.9%; p = 0.010). No paravalvular leak (PVL) was noted in the CABG + AVR group, while the incidence of moderate-to-severe PVL after PCI + TAVI was 4.9% (p = 0.027). CONCLUSION: A staged interventional approach comprises a short-term survival advantage compared with combined surgery for management of CAD and aortic stenosis. However, PCI + TAVI show a significantly higher risk of atrioventricular block and PVL. Further long-term trials are warranted.

Is It Reasonable to Perform Isolated SAVR by Residents in the TAVI Era?

BACKGROUND: The role of conventional surgical aortic valve replacement (SAVR) is increasingly questioned since the indication for transcatheter aortic valve implantations (TAVIs) is currently extended. While the number of patients referred to SAVR decreases, it is unclear if SAVR should be performed by junior resident surgeons in the course of a heart surgeons training. METHODS: Patients with isolated aortic valve replacement (AVR) were analyzed with respect to the surgeon's qualification. AVR performed by resident surgeons was compared with AVR by senior surgeons. The collective was analyzed with respect to clinical short-term outcomes comparing full sternotomy (FS) with minimally invasive surgery and ministernotomy (MS) with right anterior thoracotomy (RAT) after a 1:1 propensity score matching. RESULTS: The 30-day all-cause mortality was 2.3 and 3.4% for resident versus senior AVR groups, cerebrovascular event rates were 1.1 versus 2.6%, and no cases of significant paravalvular leak were detected. Clinical short-term outcomes between FS and minimally invasive access, as well after MS and RAT were comparable. CONCLUSION: Our current data show feasibility and safety of conventional SAVR procedure performed by resident surgeons in the era of TAVI. Minimally invasive surgery should be trained and performed in higher volumes early in the educational process as it is a safe treatment option.

Valve-in-Valve TAVR versus Redo Surgical Aortic Valve Replacement: Early Outcomes.

OBJECTIVE: This study aimed to assess short-term outcomes of patients with failed aortic valve bioprosthesis undergoing valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) or redo surgical aortic valve replacement (rSAVR). METHODS: Between 2009 and 2019, 90 patients who underwent ViV-TAVR (n = 73) or rSAVR (n = 17) due to failed aortic valve bioprosthesis fulfilled the inclusion criteria. Groups were compared regarding clinical end points, including in-hospital all-cause mortality. Patients with endocarditis and in a need of combined cardiac surgery were excluded from the study. RESULTS: ViV-TAVR patients were older (78.0 ± 7.4 vs. 62.1 ± 16.2 years, p = 0.012) and showed a higher prevalence of baseline comorbidities such as atrial fibrillation, diabetes mellitus, hyperlipidemia, and arterial hypertension. In-hospital all-cause mortality was higher for rSAVR than in the ViV-TAVR group (17.6 vs. 0%, p < 0.001), whereas intensive care unit stay was more often complicated by blood transfusions for rSAVR patients without differences in cerebrovascular events. The paravalvular leak was detected in 52.1% ViV-TAVR patients compared with 0% among rSAVR patients (p < 0.001). CONCLUSION: ViV-TAVR can be a safe and feasible alternative treatment option in patients with degenerated aortic valve bioprosthesis. The choice of treatment should include the patient's individual characteristics considering ViV-TAVR as a standard of care.

Intraoperative Noninvasive Left Ventricular Myocardial Work Indices in Patients Undergoing On-Pump Coronary Artery Bypass Surgery.

OBJECTIVES: Noninvasive echocardiographic analysis of left ventricular (LV) myocardial work (MW) enables insights into cardiac mechanics, contractility, and efficacy beyond ejection fraction (EF) and global longitudinal strain (GLS). However, there are limited perioperative data on patients undergoing coronary artery bypass graft (CABG) surgery. The authors aimed to describe the feasibility and the intraoperative course of this novel assessment tool of ventricular function in these patients, and compare it to conventional 2-dimensional (2D) and 3-dimensional (3D) echocardiographic parameters and strain analysis. DESIGN: A prospective observational study. SETTING: At a single university hospital. PARTICIPANTS: Twenty-five patients with preoperative preserved LV and right ventricular function, sinus rhythm, without significant heart valve disease or pulmonary hypertension, and an uncomplicated intraoperative course scheduled for isolated on-pump CABG surgery. INTERVENTIONS: Transesophageal echocardiography (TEE) was performed intraoperatively after the induction of anesthesia (T1), after termination of cardiopulmonary bypass (T2), and after sternal closure (T3). All measurements were performed under stable hemodynamic conditions, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤ 0.1 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: The EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2D and 3D LVEF, LV GLS, LV global work index (GWI), LV global constructive work (GCW), LV global wasted work (GWW), and LV global work efficiency (GWE). The MW analysis was feasible in all patients. Although there was no significant difference in the values of 2D and 3D EF during the intraoperative interval, GLS deteriorated significantly after CABG compared to assessment after induction of anesthesia (T1 v T2, -13.3 ± 3.0% v -11.6 ± 3.1%; p = 0.012). The GWI declined significantly after surgery (T1 v T2, 1,224 ± 312 mmHg% v 940 ± 267 mmHg%; p < 0.001), as well as GCW (T1 v T2, 1,460 ± 312 mmHg% v 1,244 ± 336 mmHg%; p = 0.005). The GWW increased after CABG (T1 v T2, 143 mmHg% (IQR 99-183) v 251 mmHg% (IQR 179-361); p < 0.001), and GWE decreased (T1 v T2, 89% (IQR 85-92) v 80% (IQR 75-87); p < 0.001). There were no significant changes in the values of 2D and 3D EF, GLS, GWI, GCW, GWW, and GWE before and after sternal closure (T2 v T3). CONCLUSION: The intraoperative analysis of noninvasive echocardiographically-assessed LV MW indices is feasible. In the short-term period after uncomplicated on-pump CABG, GLS, as well as global and constructive MW, decreased, whereas wasted work increased, resulting in a less efficient left ventricle. None of these aspects was detected by conventional echocardiographic parameters. Therefore, strain and MW analysis might be more sensitive parameters in detecting myocardial dysfunction by TEE in the perioperative setting, adding information on perioperative cardiac energetics.

Intraoperative Augmented Rotation and Circumferential Strain Compensate for Reduction of Left Ventricular Longitudinal Function After On-Pump CABG Surgery.

OBJECTIVES: Left ventricular (LV) longitudinal function is reduced after on-pump coronary artery bypass grafting (CABG), while global LV function often is preserved. There are only limited data on the underlying compensatory mechanism. Therefore, the authors aimed to describe intraoperative changes of LV contractile pattern by myocardial strain analysis. DESIGN: A prospective observational study. SETTING: At a single university hospital. PARTICIPANTS: A total of 30 patients scheduled for isolated on-pump CABG with an uneventful intraoperative course and preoperative preserved LV and RV function, sinus rhythm, without more-than-mild heart valve disease, or elevated pulmonary pressure. 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 under stable hemodynamics, in sinus rhythm or atrial pacing, and vasopressor support with norepinephrine ≤0.1 µg/kg/min. MEASUREMENTS AND MAIN RESULTS: EchoPAC v204 software (GE Vingmed Ultrasound AS, Norway) was used for analysis of 2-dimensional (2D) and 3-dimensional (3D) LV ejection fraction (EF), LV global longitudinal strain (GLS), LV global circumferential strain (GCS), LV global radial strain (GRS), LV apical rotation (aRot), LV basal rotation (bRot), and LV twist. Strain analysis was feasible in all included patients after termination of cardiopulmonary bypass (T2). Although there were no significant differences in the values of conventional echocardiographic parameters during the intraoperative interval, GLS deteriorated significantly after CABG compared to pre-bypass assessment (T1 v T2, -13.4% ± 2.9 v -11.8% ± 2.9; p = 0.007). GCS improved significantly after surgery (T1 v T2, -19.4% (IQR -17.1% to -21.2%) v -22.8% (IQR -21.1% to -24.7%); p < 0.001) as well as aRot (T1 v T2, -9.7° (IQR -7.1° to -14.1°) v -14.5° (IQR -12.1° to -17.1°); p < 0.001), bRot (T1 v T2, 5.1° (IQR 3.8°-6.7°) v 7.2° (IQR 5.6°-8.2°); p = 0.02), and twist (T1 v T2, 15.8° (IQR 11.7°-19.4°) v 21.6° (IQR 19.2°-25.1°); p < 0.001), while GRS remained unchanged. There were no significant changes in the values of GLS, GCS, GRS, aRot, bRot, or twist, as well as in the values of 2D and 3D LV EF before and after sternal closure (T2 v T3). CONCLUSION: Beyond evaluation of longitudinal LV strain, measurements of circumferential and radial strain, as well as LV rotation and twist mechanics, were feasible in the intraoperative course of this study. Reduction of longitudinal function after on-pump CABG was compensated intraoperatively by improvement of GCS and rotation in the authors' group of patients. Perioperative assessment of GCS, GRS, as well as rotation and twist, might provide deeper insight into perioperative changes of cardiac mechanics.

Acute stroke in patients undergoing coronary artery bypass grafting surgery in acute coronary syndrome: Predictors and outcomes.

OBJECTIVES: Coronary artery bypass grafting (CABG) surgery in patients with acute coronary syndrome (ACS) remains a high-risk procedure and is associated with adverse outcomes. The risk factors of acute stroke in the above-mentioned patients stay unclear and some appropriate data is lacking in the literature. Thus, we aimed to investigate the predictors of acute stroke in patients undergoing CABG surgery in ACS. METHODS: The retrospective single-centre cohort analysis was conducted. All patients (n = 1344) who suffered from acute coronary syndrome and underwent CABG procedure at the University hospital Cologne from June 2011 until October 2019 were included in our study. In order to find the risk factors of acute stroke after bypass surgery, patients were divided into two groups (non-stroke group (n = 1297) and stroke group (n = 47)). In order to even above-mentioned groups propensity score matching (PSM) analysis was performed (non-stroke group (n = 46) and stroke group (n = 46). RESULTS: Duration of cardiopulmonary bypass (p = .015) and cross clamp time (p = .006) were significantly longer in patients who suffered stroke. Perioperative myocardial infarction was significantly higher (p = .030) in the stroke group. Likewise, the duration of intensive care unit stay (p < .001) and in-hospital stay (p < .001) were significantly longer in patients with stroke. However, the mortality rate did not differ significantly (p = .131) between above-mentioned groups. Univariate and multivariate analysis showed cardiogenic shock (p = .003), peripheral vascular disease (PVD, p = .025) and previous stroke (p = .045) as relevant independent predictors for acute stroke after CABG procedure in patients with ACS. CONCLUSION: Based on our findings, acute stroke after bypass surgery in patients with ACS is associated with increased mortality and adverse outcomes. Cardiogenic shock, peripheral vascular disease and previous stroke were independent predictors of stroke after CABG procedure. Therefore, preoperative evaluation of potential risk factors may be crucial to improve postoperative results.

Clinical results and 30-day outcomes of self-expanding transcatheter aortic valves: comparative case-matched analysis of CoreValve® versus ACURATE neo™.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is associated with excellent results in patients with severe aortic stenosis. In highly calcified aortic anuli with increased risk of annulus rupture and in favor of the supra-annular design, self-expandable prostheses are frequently used. In this regard, we aimed to perform a comparative analysis of clinical and 30-day outcomes after TAVR using the self-expanding CoreValve® Evolut R or ACURATE neo™ prosthesis. METHODS: Out of 343 consecutive patients treated with either CoreValve® Evolut R or ACURATE neo™ from January 2014 to December 2017, 76 patients were assigned each per group after 1:1 propensity score matching in regard of preoperative characteristics. Pre- and periprocedural outcomes were retrospectively collected and assessed. Outcomes at 30 days are reported according to the established Valve Academic Research Consortium (VARC-2) criteria. RESULTS: Device success and 30-day survival accounted for 93.4% (n = 71), respectively 97.4% (n = 74) in both groups (p = 1.00). No statistically significant differences regarding clinical parameters were observed. The combined safety endpoint at 30 days was comparable (84.2% (n = 64) CoreValve® vs 85.5% (n = 65) ACURATE neo™; p = 0.848). Except a trend toward higher stroke (p = 0.08) and pacemaker (p = 0.07) rate in the CoreValve® group, major vascular complications, incidence of life-threatening or disabling bleeding, and incidence of postoperative acute kidney injury were comparable. Postoperative hemodynamic parameters showed no significant differences between the implanted valves. CONCLUSION: Both self-expandable prostheses showed good postoperative hemodynamic performance with a low incidence of severe paravalvular leakage, all- cause mortality, and comparable clinical outcomes.