Artificial intelligence-based body composition predicts postoperative complications and mortality in advanced heart failure patients receiving long-term mechanical circulatory support

Background

Obesity is an independent cardiovascular risk factor and is associated with higher postoperative infection rates in patients after cardiac surgery. However, in heart failure, obesity has been described as beneficial in terms of survival (“obesity paradox”); whereas sarcopenia is associated with poor prognosis. An increasing number of advanced heart failure patients requires surgical treatment in terms of left ventricular assist device (LVAD) implantation. The postoperative in-hospital survival has improved in recent years but is still relatively high (11.1%). The impact of body composition on outcome in this population remains unclear.

Purpose

The aim of this investigation was to examine the preoperative computed tomography (CT) body composition based on artificial intelligence (AI) analysis as a predictor of the postoperative outcome in advanced heart failure patients, who underwent LVAD implantation.

Methods

Preoperative CT scans of 137 patients who received LVAD implantations between 2015 and 2020 were retrospectively analyzed using an AI-powered automated software tool based on a convolutional neural network, U-net, developed for image segmentation (Visage version 7.1., Visage Imaging GmbH, Berlin, Germany; Figure 1). Assessment of body composition included visceral and subcutaneous adipose tissue areas (VAT, SAT), psoas and total abdominal muscle areas (PMA, TAMA) and sarcopenia (defined as lumbal skeletal muscle index ≤38.5 cm2/m2 in women and ≤54.4 cm2/m2 in men). The body composition parameters were correlated with postoperative major complication rates and survival.

Results

The mean age of patients was 58.21±11.9 years; 122 (89.1%) were male. Most patients had severe heart failure requiring inotropes (INTERMACS profile I-III, 71.9%) secondary to coronary artery diseases or dilated cardiomyopathy (96.4%). 44 (32.1%) patients were obese (BMI ≥30 kg/m2), 96 (70.1%) were sarcopene and 19 (13.9%) were sarcopene obese. Adipose tissue was associated with a significantly higher risk of overall postoperative complications (SAT 158.22 cm2 [63.09, 256.78 cm2] vs. 124.04 cm2 [42.86, 187.68 cm2], p=0.049) and in-hospital mortality (VAT 168.11 cm2 [134.19, 285.27 cm2] vs. 135.42 cm2 [49.44, 227.91 cm2], p=0.033; SAT 227.28 cm2 [139.38, 304.35 cm2] vs. 173.81 cm2 [97.65, 254.16 cm2], p=0.009). Sarcopenia did not influence the postoperative outcome and survival within 1 year post LVAD implantation.

Conclusions

Preoperative AI-based CT body composition identifies patients with poor prognosis after LVAD implantation. Adipose tissue areas predict in-hospital mortality, thus, obesity as a perioperative risk factor outweighs the protective effect known in heart failure patients when undergoing LVAD implantation.

Funding Acknowledgement

Type of funding sources: None.

The value of diastolic speckle-tracking parameters in predicting outcome after surgical ventricular restoration

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): DZHK (German Centre for Cardiovascular Research) BMBF (German Ministry of Education and Research)

Background. Parameters of speckle-tracking echocardiography (STE) are incorporated into the integrative assessment of left ventricular (LV) diastolic function 1. In this study we aimed to evaluate both established and novel STE parameters of LV diastolic function and their prognostic role in patients with LV anteroapical aneurysm planned for surgical ventricular restoration (SVR).

Methods. We retrospectively examined data of 137 patients (60 ± 11 years, 25% women) with anteroapical LV aneurysm who underwent SVR and for whom preoperative echocardiography was available and feasible for STE and for conventional assessment of LV diastolic function by transmitral flow. STE parameters evaluated were: left atrial reservoir strain (LAS), early and late global diastolic strain rate (GLSRe and GLSRa), ratio of early-to-late diastolic strain rate (GLSRe/GLSRa), and ratio of early diastolic transmitral flow velocity (E) to GLSRe and to GLSRa. In 24 patients we evaluated an association of diastolic echocardiographic parameters with mean pulmonary artery pressure (PAPm) and mean pulmonary capillary wedge pressure (PCWPm) obtained invasively within 6 days of echocardiography. Preoperative echocardiographic parameters were assessed in whole cohort of patients for the association with an outcome, defined as all-cause mortality, LV assist device implantation, or heart transplantation.

Results. During a median follow-up of 4.7 years (IQR: 1.4-8.1 years) events occurred in 59 patients. GLSRa, E/GLSRa and LAS demonstrated significant correlation with PAPm and PCWPm (Table 1). GLSRa with optimal cut-off value of ≤ 0.41 s-1 was able to detect PAPm >30 mmHg with sensitivity of 0.8 and specificity of 0.8 (AUC 0.85; 95% CI 0.68-1.0; p = 0.008). E/GLSRa ≥1.24 m was able to detect PAPm >30 mmHg with sensitivity of 1.0 and specificity of 0.8 (AUC 0.87; 95%CI 0.7-1.0; p = 0.005). There was significant difference in event-free survival between groups stratified by cut-offs for GLSRa (Fig. 1A) and E/GLSRa (Fig. 1B). After adjustment for important clinical (age, sex, plasma creatinine, atrial fibrillation) and echocardiographic parameters (fractional shortening and LV end-systolic volume index) GLSRa and E/GLSRa remained an independent predictors of events (HR 0.16; 95% CI: 0.03-0.86; p = 0.032 and HR 1.22; 95% CI: 1.03-1.43; p = 0.018) and demonstrated higher prognostic value compared to LAS, other STE parameters and conventional parameters of LV diastolic function.

Conclusion. Late diastolic longitudinal strain rate and ratio of early diastolic transmitral flow velocity to late diastolic longitudinal strain rate demonstrated association with hemodynamic parameters in patients with LV anteropaical aneurysm and might be used for the evaluation of LV diastolic function. These parameters showed prognostic value for patients underwent SVR and could be implemented for preoperative evaluation of these patients. Abstract Table 1. Correlation data  Abstract Figure 1. Survival curves

Cardiac computed tomography for therapy targeting in surgical repair of anteroapical left ventricular aneurysms: assessment of aneurysm volume and of anticipated residual left ventricular volume

Funding Acknowledgements

Type of funding sources: None.

Background

Surgical ventricular repair (SVR) is an established treatment option in patients with heart failure (HF) due to left ventricular (LV) aneurysms, whereby LV volume reduction is the principal therapeutic target. Precise planning therefore is essential for postoperative improvement of HF symptoms.

Purpose

In this study we evaluated the potential of cardiac computed tomography (CCT) to estimate the aneurysm volume and to predict the achievable residual LV volume.

Methods

 205 patients (11/2005-01/2016, m:w = 151:54, median 63.4 years; mean NYHA class 3.03) with anteroapical LV aneurysm underwent SVR combined with coronary artery bypass grafting (77%), mitral valve repair/replacement (19%), and LV thrombectomy (19%). CCT was performed before and 7 days after surgery. Volumetric assessment was made using dedicated software (syngo.via Cardiac Function, Siemens AG).  Preoperative CCT data of 48 consecutive patients were analyzed and then matched with effectively achieved postoperative volumes. To separate the aneurysm volume in the systole and diastole a plane determined by three landmarks on borders of scared to intact LV myocardium (antero-septal, lateral and inferior) was used. In this way ensued the retrospective estimation of the aneurysm volume (AnV/AnVI) and anticipated LV end diastolic and end systolic volume (LVEDVI, LVESVI).

Results

Mean diastolic and systolic estimated AnV were 92 ± 56.6 ml and 83.5 ± 61.6 ml respectively. Relation of AnV to LVEDV and to LVESV was 29.2% and 38.2%, correspondingly. There was significant correlation between anticipated and effectively achieved LVEDV and LVESV (r = 0.87 and r = 0.88, respectively, p < 0.0001), and their indexed values (r = 0.83 and r = 0.83, respectively, p < 0.0001). Anticipated LVEDVI was only 10.3 ± 22.5 ml/m2 greater than achieved LVEDVI (p = 0.003), and anticipated LVESVI was only 2.4 ± 20.3 ml/m2 greater than achieved LVESVI (p = 0.433).

Conclusions

Estimation of aneurysm volume and anticipated postoperative LV volume allows to predict if the therapeutic targets can be successfully achieved in individual patients. Based on the CCT assessment we propose an approach for surgical planning in anterior LV aneurysms.

Two-dimensional echocardiography compared to cardiac computed tomography for assessment of left ventricular volume and function in patients with anteroapical aneurysm

Funding Acknowledgements

Type of funding sources: None.

Background. Two-dimensional (2D) echocardiography is widely accepted method for the assessment of left ventricular (LV) morphology and function after myocardial infarction and for initial preoperative evaluation of patients planned for surgical ventricular repair (SVR). Magnetic resonance imaging and cardiac computer tomography (CT) provide more accurate measurements, but not always available.

Purpose. The aim of this study was to compare 2D-echocardiography and CT for preoperative assessment of patients with LV aneurysm in order to optimize the perioperative management in SVR.

Methods. Patients (n = 179, mean age 62.6 ± 11 years, 23.5% women) with LV anteroapical aneurysm due to myocardial infarction were examined by echocardiography and CT before SVR. LV end-diastolic and end-systolic volumes (LVEDV and LVESV) and ejection fraction (EF) obtained by two methods were compared pairwise. Prognostic role for the prediction of all-cause death was assessed for preoperative parameters in multivariate Cox regression model adjusted for patient age, sex, NYHA class, diabetes mellitus, renal failure, atrial fibrillation and arterial hypertension.

Results. There was a strong correlation for preoperative LVEDV and LVESV measured by echocardiography and CT (r = 0.85, r = 0.87, p < 0.0001), however volumes obtained by echocardiography were smaller compared to those by CT (Table) with higher difference in patients with more dilated LV, as demonstrated by Bland-Altman analysis (Fig.). No significant difference in mean preoperative EF was observed with moderate correlation between two methods (r = 0.67, p < 0.0001). In total 68 patients died during median follow up of 5.3 years (IQR: 1.7-8.7 years) after SVR. Comparable predictive value was demonstrated for LVEDV measured by CT and echocardiography (for 10 ml increase HR = 1.04, p = 0.004 and HR = 1.06, p = 0.0001), as well as for LVESV (for 10 ml increase HR = 1.04, p = 0.001 and HR = 1.07, p = 0.0001) and for EF (for 5% increase HR = 0.83, p = 0.004 and HR = 0.81, p = 0.004).

Conclusion. In patients with LV aneurysm 2D-echocardiography may be used for the assessment of LV volumes and function and have similar prognostic role compared to CT in patients evaluated for SVR. Underestimation of LV volumes by echocardiography must be considered, especially in patients with more dilated LV.

Comparison of CT and echocardiography Parameter CT Echo Mean difference p-value LVEDV, ml LVESV, ml EF, % 289 ± 104 198 ± 97 34 ± 12 222 ± 81 149 ± 67 35 ± 9 67 ± 56 49 ± 51 -0.9 ± 9.2 <0.0001 <0.0001 0.215 Abstract Figure. Bland-Altman plots for LVEDV and LVESV

Prognostic role of left ventricular diastolic function assessed by speckle tracking echocardiography in patients after surgical ventricular repair

Background

Assessment of left ventricular (LV) diastolic function brings important prognostic information for patients with heart failure and could be evaluated by speckle tracking echocardiography (STE). Less known about its role in patients planned for surgical ventricular repair due to LV aneurysm.

Purpose

The aim of this study was to evaluate the prognostic role of STE parameters of LV diastolic function for prediction of all-cause mortality in patients after surgical ventricular repair.

Methods

We retrospectively evaluated data of 163 consecutive pts (mean age 62.3±11.5 years, 74.8% males) with anteroapical LV aneurysm who underwent surgical ventricular repair combined with coronary artery bypass surgery (71.8%) Prognostic role for prediction of all-cause mortality was assessed for various STE parameters, including left atrial strain (LAS) measured as peak reservoir strain and for the ratio of early to late global longitudinal strain rate (GLSRe/GLSRa).

Results

During a median follow-up of 4.7 years (IQR: 1.6–8.9 years) there were 65 deaths, 5 year survival rate was 73.8 (95% CI 67–79%). Baseline ejection fraction, end-diastolic and end-systolic volumes of LV did not differ between pts who died and survived at 5 year after the surgery, whereas LAS was significantly higher and GLSRe/GLSRa was significantly lower in survivors. Cox proportional hazard model adjusted to demographic and clinical variables demonstrated that LAS and GLSRe/GLSRa were independent predictors of all-cause death, with HR of 0.79 (95% CI 0.66–0.95, p=0.012) for each 5% increase of LAS and HR of 1.24 (95% CI 1.1–1.4, p=0.001) for each 0.5 increase of GLSRe/GLSRa. Moreover, GLSRe/GLSRa remained an independent predictor after additional adjustment for LV end-systolic volume, sphericity index and presence of mitral insufficiency of grade 2 and higher. A significant difference in median survival time was demonstrated according to the following cut-offs: LAS ≥16.7% (12.1 vs. 6.4 years, p=0.01), GLSRe/GLSRa ratio ≥2.3 (3.3 years vs. 10.2 years, p=0.0005) (Figure). The classification and regression tree analysis with the application of all two-dimensional, Doppler and various speckle-tracking echocardiographic parameters revealed that GLSRe/GLSRa and LAS were the most important echocardiographic variables for risk stratification for 5-year mortality.

Conclusion

This study demonstrates that STE parameters of LV diastolic function are important predictors of all-cause mortality after surgical ventricular repair due to anteroapical aneurysm of LV and could be used in the preoperative decision-making process.

Funding Acknowledgement

Type of funding source: None

1036 Prognostic role of left ventricle longitudinal strain for the prediction of survival after surgical ventricular repair

Background

Surgical ventricular repair (SVR) in patients with ischemic cardiomyopathy is aimed to reshape left ventricle (LV) and reduce its volume in order to improve prognosis and quality of life. There are controversies regarding benefit of SVR, especially in patients with severely enlarged LV.

Purpose

Our purpose was to investigate prognostic value of LV longitudinal strain for survival and for the improvement of LV function after SVR in patients with anteroapical LV aneurysm.

Methods

218 pts (2005-2018, mean age 63.6 ± 11.2y, 73.9% males) with anteroapical LV aneurysm due to myocardial infarction underwent SVR combined with coronary bypass grafting (77.5%), mitral valve repair (18.3%) and LV thrombectomy (22.0%). Preoperative strain analysis was done retrospectively for 146 patients. Prognostic value of strain was tested in pts according to the LV end systolic volume index (LVESVI) with the cut-off value of 60ml/m². In 17 pts 1-year follow-up with strain quantification was done.

Results

During a median follow-up of 3.9 years (IQR: 1.0-6.8 years) there were 68 deaths and 1 patient was lost to follow-up. 30-days survival rate was 93.5% (95%CI: 90.3; 96.9%), 5 year survival – 72.5% (95%CI: 66.0-79.6%). Pts who died were significantly older, with higher proportion of diabetes (DM), peripheral artery disease, renal failure (RF) and atrial fibrillation (AF). Baseline ejection fraction (EF) and global longitudinal strain (GLS) did not differ significantly. Whereas basal longitudinal strain (BLS) was higher (more negative) in pts who survived (-11.4 ± 3% vs. -10.1 ± 4%, p = 0.027). Risk stratification by tertiles revealed that BLS was a significant predictor of survival. The risk of dying was 3 times higher for pts in the lowest tertile compared to those in the highest tertile (HR: 2.94, 95%CI:1.37-6.25, p = 0.013). When adjusted to age, AF, DM, RF, and previous heart surgery, BLS was an independent predictor of death (HR = 1.14, 95%CI:1.03;1.26, p = 0.032). At 1-year follow-up (12.7 ± 5.1 months) there was significant decrease of LV end-diastolic and end-systolic volume indices, from 102.8 ± 24.1 ml/m² to 77.9 ± 24 ml/m² (p < 0.001) and from 67 ± 23.2 ml/m² to 44.3 ± 7.6 ml/m² (p < 0.001), correspondingly, and increase of EF from 36.3 ± 9.4% to 44.4 ± 7.6% (p = 0.001). The mean systolic GLS improved from -6.6 ± 2.6% to -8.7 ± 3.2%, p = 0.008. Among 81 segments with baseline hypokinesia, 44 segments (54.3%) recovered their contractility, 36 segments (44.4%) remained hypokinetic and 1 segment deteriorated to akinesia. Mean systolic strain of segments which showed recovery was -6.6 ± 4.0% compared to -3.8 ± 4.5% with no improvement (p = 0.005). Cut-off value of systolic strain for prediction of recovery was -5.4 % (AUC = 0.69, p = 0.004; PPV = 0.73, NPV = 0.61).

Conclusion

Our study demonstrates that BLS is an independent predictor of survival after SVR in patients with LV anteroapical aneurysm. Furthermore, higher systolic strain predicts recovery of LV regional function at 1-year after SVR.

P819 Outflow graft twist occlusion in the heartmate 3 left ventricular assist system in 7 cases: analysis of potential mechanisms using computed tomography

Background

Twist of the outflow graft (OG) of the HeartMate 3 left ventricular (LV) assist device (HM3) with subsequent occlusion is a rare, but life-threatening complication.

Purpose

We evaluated if potential implantation technique dependent mechanisms of OG twist can be predicted by multislice computed tomography (MSCT).

Methods

We retrospectively analyzed clinical, echocardiographic and MSCT data of 7 patients with angiographically proven and surgically corrected OG twist and of 11 consecutive patients without any type of pump obstruction. MSCT parameters were: position of inflow cannula related to anatomical LV apex (1), angulation of axis of inflow cannula related to LV axis (2), orientation of outflow channel of the pump housing related to LV axis (3), OG course (4). Echocardiographic parameters were LV end-diastolic diameter (LVEDD) and aortic valve opening.

Results

Mean time from implantation to twist was 563 ± 161 days. Preoperative LVEDD (64.6 ± 9.8 mm vs. 67.4 ± 10.2 mm, p = 0.563) was similar. LVEDD reduction after implantation (20% vs. 28%) and prevalence of aortic valve opening was higher in the twist group (71% vs. 45%). The MSCT measurements showed a high degree of heterogeneity in both groups: (1) differed from superior to infero-lateral; (2) varied from cranial to caudal, lateral and medial; (3) varied from antero-septal to inferior. (4) showed an incidence of non-obstructive kinking of 29% and 36%, respectively.

Conclusion

Marked heterogeneity of the measured MSCT parameters was observed in both groups. No specific pattern or geometric relation could be attributed to the OG twist phenomenon.

Reliability of tissue Doppler wall motion monitoring after heart transplantation for replacement of invasive routine screenings by optimally timed cardiac biopsies and catheterizations

BACKGROUND

Invasive screenings at predefined time intervals for acute rejection and transplant coronary artery disease (TxCAD) are standard procedures. However, cardiac biopsies and catheterizations are distressing and risky for the patients and are also costly. We assessed the reliability of pulsed-wave tissue Doppler imaging (PW-TDI) for the timing of invasive examinations in heart recipients in an attempt to avoid unnecessary endomyocardial biopsies (EMBs) and catheterizations.

METHODS AND RESULTS

PW-TDI obtained at the basal left ventricular posterior wall before 408 EMBs and 293 catheterizations was tested for its diagnostic value regarding rejection and TxCAD with the use of International Society of Heart and Lung Transplantation biopsy grading, coronary angiography, and intravascular ultrasound as standards. Early diastolic peak wall motion velocity and relaxation time showed high sensitivities for clinically relevant rejection diagnosis (90.0% and 93.3%, respectively). The negative and positive predictive values for rejection of diastolic parameter changes appeared high enough (up to 96% and 92%, respectively) to allow a reliable noninvasive PW-TDI monitoring with efficiently timed, instead of routinely scheduled, EMBs. At definite cutoff values for systolic parameters, the probability for TxCAD reached 92% to 97%. The Fisher classification functions allowed TxCAD exclusion with 80% probability.

CONCLUSIONS

Without diastolic parameter changes, acute rejection can be practically excluded, and serial PW-TDI can save patients from routine EMBs. The high specificity and negative predictive value for TxCAD of reduced systolic peak velocities and extended systolic time allow optimized timed catheterizations. Peak systolic velocity and systolic time allow diagnostic classifications that enable patients without known TxCAD but with high risk for catheterization to be spared routine angiographies.

Clinical experience with minimally invasive coronary artery and mitral valve surgery with the advantage of cardiopulmonary bypass and cardioplegic arrest using the Port Access technique

To minimize surgical trauma, the use of Port Access cardiac surgery was initiated in patients (pts) with coronary artery disease (CAD) (42 pts) or mitral valve disease (MVD) (24 pts) in March 1996 at our institution. Altogether 42 pts (36 men, 6 women; age 31-75 years, median 59.0 years) with isolated lesions of the left anterior descending (LAD) artery underwent Port Access coronary artery surgery (PACAS). A small (5-9 cm) incision was done parasternally on top on the fourth rib. The left internal mammary artery (LIMA) was dissected through the minithoracotomy or by using an additional thoracoscopic approach. A total of 24 pts (12 men, 12 women; age 30-75 years, median 62 years) underwent Port Access mitral valve surgery (PAMVS). In these pts the procedure was performed through a small right thoracotomy (6-8 cm). In all cases, endovascular cardiopulmonary bypass (CPB) was instituted through femoral cannulation, and an additional endoaortic balloon catheter was introduced into the ascending aorta for aortic occlusion. In pts with PACAS the survival was 98% (41/42) and in the PAMVS group 100%. All pts but one survived the PACAS and are well today. There were no deaths in the PAMVS group. The hospital stay was reduced by 1 day on average after PACAS and 3 days after PAMVS. Thus in well selected patients Port Access cardiac surgery represents a safe and feasible minimally invasive surgical approach that avoids the potential complications of a sternotomy while offering the advantages and safety of CPB and cardioplegic arrest. This minimally invasive approach offers a shortened hospital stay and earlier rehabilitation.

Clinical experiences with minimally invasive mitral valve surgery using a simplified Port Access technique

OBJECTIVE

Using the initial experiences with the Port-Access technique for the treatment of mitral valve disease some changes were made thus resulting in more simple and faster procedures.

METHODS

Twenty-nine patients (13 male, 16 female, aged 30 to 75 years, median 62.5 +/- 11.0 years) underwent minimally invasive mitral valve surgery between May 1996 and December 1997. The underlying diseases were: mitral valve insufficiency (n = 16), mitral valve stenosis (n = 7) and combined mitral valve disease (n = 6). Through a small right thoracotomy (5-7 cm) access to the pericardium and the heart was gained. Cardiopulmonary bypass was instituted through femoral cannulation and an intraaortic balloon-catheter was introduced for aortic occlusion, aortic root venting and delivery of cold crystalloid cardioplegia. Mitral valve repair (five patients) or replacement (24 patients) was performed.

RESULTS

There was no death during the whole follow-up period. There was no perivalvular leak and only minor residual mitral valve regurgitation was observed on intraoperative or postoperative (3 months) transesophageal echocardiography in three patients. There was no postoperative study-related complication. Time of ventilation and intensive care unit were comparable with the data of patients undergoing conventional mitral valve surgery but hospital stay was shorter in the last 10 consecutive cases.

CONCLUSIONS

This simplified technique of mitral valve surgery combines the advantage of less invasive operative and good cosmetic results with the safety of conventional mitral valve surgery. At our institution this technique presents in well selected patients suffering from mitral valve disease the procedure of choice.