Purpose The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root.Methods This proof... Show morePurpose The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root.Methods This proof-of-concept study used four-dimensional (4D) flow cardiovascular MR (4D flow CMR) data of five healthy controls, five patients with heart failure with preserved ejection fraction and five patients with aortic stenosis (AS). A PC through-plane generated by 4D flow data was treated as a 2D PC plane and compared with the original 4D flow. Visual assessment of flow vectors was used to assess helicity and vorticity. We quantified flow displacement (FD), systolic flow reversal ratio (sFRR) and rotational angle (RA) using 2D PC.Results For visual vortex flow presence near the inner curvature of the ascending aortic root on 4D flow CMR, sFRR demonstrated an area under the curve (AUC) of 0.955, p<0.001. A threshold of >8% for sFRR had a sensitivity of 82% and specificity of 100% for visual vortex presence. In addition, the average late systolic FD, a marker of flow eccentricity, also demonstrated an AUC of 0.909, p<0.001 for visual vortex flow. Manual systolic rotational flow angle change (ΔsRA) demonstrated excellent association with semiautomated ΔsRA (r=0.99, 95% CI 0.9907 to 0.999, p<0.001). In reproducibility testing, average systolic FD (FDsavg) showed a minimal bias at 1.28% with a high intraclass correlation coefficient (ICC=0.92). Similarly, sFRR had a minimal bias of 1.14% with an ICC of 0.96. ΔsRA demonstrated an acceptable bias of 5.72°—and an ICC of 0.99.Conclusion 2D PC flow imaging can possibly quantify blood flow helicity (ΔRA) and vorticity (FRR). These imaging biomarkers of flow helicity and vorticity demonstrate high reproducibility for clinical adoption. Show less
Sbrollini, A.; Barocci, M.; Mancinelli, M.; Paris, M.; Raffaelli, S.; Marcantoni, I.; ... ; Burattini, L. 2023
Heart failure (HF) diagnosis, typically visually performed by serial electrocardiography, may be supported by machine-learning approaches. Repeated structuring & learning procedure (RS & LP... Show moreHeart failure (HF) diagnosis, typically visually performed by serial electrocardiography, may be supported by machine-learning approaches. Repeated structuring & learning procedure (RS & LP) is a constructive algorithm able to automatically create artificial neural networks (ANN); it relies on three parameters, namely maximal number of hidden layers (MNL), initializations (MNI) and confirmations (MNC), arbitrarily set by the user. The aim of this study is to evaluate RS & LP robustness to varying values of parameters and to identify an optimized combination of parameter values for HF diagnosis. To this aim, the Leiden University Medical Center HF data-base was used. The database is constituted by 129 serial ECG pairs acquired in patients who experienced myocardial infarction; 48 patients developed HF at follow-up (cases), while 81 remained clinically stable (controls). Overall, 15 ANNs were created by considering 13 serial ECG features as inputs (extracted from each serial ECG pair), 2 classes as outputs (cases/controls), and varying values of MNL (1, 2, 3, 4 and 10), MNI (50, 250, 500, 1000 and 1500) and MNC (2, 5, 10, 20 and 50). The area under the curve (AUC) of the receiver operating characteristic did not significantly vary with varying parameter values (P >= 0.09). The optimized combination of parameter values, identified as the one showing the highest AUC, was obtained for MNL = 3, MNI = 500 and MNC = 50 (AUC = 86 %; ANN structure: 3 hidden layers of 14, 14 and 13 neurons, respectively). Thus, RS & LP is robust, and the optimized ANN represents a potentially useful clinical tool for a reliable auto-matic HF diagnosis. Show less
Functional mitral regurgitation (MR) – also referred to as secondary MR – is a disease condition which results from a combination of annular dilatation, papillary muscle displacement with increased... Show moreFunctional mitral regurgitation (MR) – also referred to as secondary MR – is a disease condition which results from a combination of annular dilatation, papillary muscle displacement with increased systolic leaflet tethering, and reduced closing forces, due to regional or global left ventricular (LV) remodelling.Functional MR is a common phenomenon and can be classified as either ischaemic or non-ischaemic, based on aetiology of LV remodelling. Regardless of aetiology, functional MR carries a poor prognosis.The primary step in the treatment of patients with functional MR consists of optimal medical and device therapy. In patients with persistence of MR despite optimal medical and device therapy, surgical treatment options can be considered. Over the past decades, many surgical treatment options have been developed, of which mitral valve repair by implantation of a restrictive mitral annuloplasty (RMA) ring forms the mainstay.In this thesis an integrated medico-surgical approach for patients with functional MR was examined, consisting of optimal medical and device therapy combined with RMA, and additional surgical interventions when indicated. The indication for each surgical intervention was determined after careful balancing of treatment options by the multidisciplinary Heart Team – consisting of heart failure specialists, interventional cardiologists, arrhythmia cardiologists and cardiac surgeons. Focus of this thesis was to determine (long-term) clinical and echocardiographic outcomes after this approach and to identify which patients are (un)likely to benefit from it. Show less
This thesis has shown that significant lead-induced TR due to the mechanical presence of an RV-lead though the tricuspid valve was associated with worse long-term prognosis. CRT is one of the... Show moreThis thesis has shown that significant lead-induced TR due to the mechanical presence of an RV-lead though the tricuspid valve was associated with worse long-term prognosis. CRT is one of the main therapeutic breakthroughs in heart failure of the last decade but patients included in landmark trials do not completely mirror patients undergoing CRT in the clinical practice, who are usually older and have more frequently associated comorbidities such as renal dysfunction, diabetes or atrial fibrillation. This thesis shows a beneficial, although limited, effect of CRT also in elderly, in patients with diabetes and CKD stage 4, and therefore suggests that this therapy should not be withheld based on certain co-morbidities or on age alone. Furthermore, it shows that RBBB in patients referred to CRT and favourable RV-function improvement after CRT were associated with CRT outcomes. To improve clinical risk-stratification, this thesis proposed a CRT-SCORE using CRT-specific parameters and showed to be valuable in risk-estimation that may assist clinicians in counseling patients and guide clinical shared decision-making. Finally, novel approaches to optimize patient selection are presented in this thesis. SDI, a 3D-echocardiography LV-dyssynchrony measurement and T1-mapping, a novel CMR-technique to quantify diffuse myocardial fibrosis were significantly associated with CRT outcomes. Show less
This thesis evaluates, using various methods, two important surgical procedures currently used in heart failure patients: surgical ventricular restoration and restrictive mitral annuloplasty. The... Show moreThis thesis evaluates, using various methods, two important surgical procedures currently used in heart failure patients: surgical ventricular restoration and restrictive mitral annuloplasty. The conductance catheter was used to analyze the hemodynamic effects of heart failure surgery invasively. It demonstrated improvement in systolic function of the left ventricle for both procedures at long term follow-up. Diastolic function demonstrated signs of impairment, although the functional effect remained limited, regarding limited or no increase in left ventricular end-diastolic pressure for SVR and RMA, respectively. Furthermore, assessment of left ventricular volumes demonstrated persistent reverse remodeling at follow-up. Clinical performance demonstrated significant improvement for both surgical procedures. The hemodynamic results together with the positive clinical outcome for both surgical procedures supports the use of these procedures in end-stage heart failure patients. Regarding the fact that using the conductance catheter is time consuming and can be burdensome for patients, a demand for less invasive methods was generated. Evaluation of alternative methods demonstrated that heart failure surgery can also be evaluated by single-beat analysis, a simplified method of the conventional conductance catheter method avoiding load interventions by temporary vena cava occlusions. Furthermore, echocardiography and to a certain extent, serum biomarker analysis can also be used. Show less
