Echocardiographic and clinical features of patients developing prosthesis-patient mismatch after TAVR: insights from the Recovery TAVR registry.

BACKGROUND: The impact of prosthesis-patient mismatch (PPM) on major endpoints after transcatheter aortic valve replacement (TAVR) is controversial and the effects on progression of heart damage are poorly investigated. Therefore, our study aims to evaluate the prevalence and predictors of PPM in a "real world" cohort of patients at intermediate and low surgical risk, its impact on mortality and the clinical-echocardiographic progression of heart damage. METHODS: 963 patients who underwent TAVR procedure between 2017 and 2021, from the RECOVERY-TAVR international multicenter observational registry, were included in this analysis. Multiparametric echocardiographic data of these patients were analyzed at 1-year follow-up (FU). Clinical and echocardiographic features were stratified by presence of PPM and PPM severity, as per the most current international recommendations, using VARC-3 criteria. RESULTS: 18% of patients developed post-TAVR. PPM, and 7.7% of the whole cohort had severe PPM. At baseline, 50.3% of patients with PPM were male (vs 46.2% in the cohort without PPM, p=0.33), aged 82 (IQR 79-85y) years vs 82 (IQR 78-86 p=0.46), and 55.6% had Balloon-Expandable valves implanted (vs 46.8% of patients without PPM, p=0.04); they had smaller left ventricular outflow tract (LVOT) diameter (20 mm, IQR 19-21 vs 20 mm, IQR 20-22, p=0.02), reduced SVi (34.2 vs 38 ml/m2, p<0.01) and transaortic flow rate (190.6 vs 211 ml/s, p<0.01). At pre-discharge FU patients with PPM had more paravalvular aortic regurgitation (moderate-severe AR 15.8% vs 9.2%, p<0.01). At 1-year FU, maladaptive alterations of left ventricular parameters were found in patients with PPM, with a significant increase in end-systolic diameter (33 mm vs 28 mm, p=0.03) and a significant increase in left ventricle end systolic indexed volume in those with moderate and severe PPM (52 IQR 42-64 and 52, IQR 41-64 vs.44 IQR 35-59 in those without, p=0.02)). No evidence of a significant impact of PPM on overall (p=0.71) and CV (p=0.70) mortality was observed. Patients with moderate/severe PPM had worse NYHA functional class at 1 year (NYHA III-IV 13% vs 7.8%, p=0.03). Prosthesis size≤23 mm (OR 11.6, 1.68-80.1) was an independent predictor of PPM, while SVi (OR 0.87, 0.83-0.91, p<0.001) and LVOT diameter (OR 0.79, 0.65-0.95, p=0.01) had protective effect. CONCLUSIONS: PPM was observed in 18% of patients undergoing TAVR. Echocardiographic evaluations demonstrated a PPM-related pattern of early ventricular maladaptive alterations, possibly precursor to a reduction in cardiac function, associated with a significant deterioration in NYHA class at 1 year. These findings emphasize the importance of prevention of PPM of any grade in patients undergoing TAVR procedure, especially in populations at risk.

Potential role of cardiopulmonary exercise testing in evaluating functional improvement after transcatheter edge-to-edge tricuspid valve repair: a case report.

Background: Tricuspid regurgitation (TR) is common and severe or greater TR is linked to poor prognosis. Treatment of TR with transcatheter edge-to-edge repair has emerged as a safe and potentially effective therapy in these patients. However, the impact of transcatheter tricuspid repair on functional capacity remains to be elucidated. Case summary: We describe the case of a 77-year-old woman complaining of heart failure symptoms, undergoing transcatheter edge-to-edge valve repair for severe TR with the PASCAL Ace® device. One month later, cardiopulmonary exercise testing (CPET) showed significant improvement in peak O2 uptake and O2 pulse compared with the test performed before the procedure. Discussion: A positive impact of novel transcatheter edge-to-edge valve repair on symptoms and quality of life in patients with severe or greater TR at prohibitive surgical risk has recently emerged. The presence of severe TR has prognostic relevance, and novel percutaneous tricuspid valve repair systems have emerged in the last few years. Cardiopulmonary exercise testing is an established tool to assess functional capacity and prognosis in heart failure patient. Detecting functional capacity improvement after transcatheter edge-to-edge repair for severe TR can be challenging, and CPET may arise as a promising tool to help these purposes.

Left Atrial Strain to Predict Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery being associated with poorer outcomes. Revealing before the operation of left atrial subtle structural/functional abnormalities may help to identify patients at increased risk of POAF. We investigated the role of left atrial strain parameters by preoperative speckle tracking echocardiography as independent predictors of POAF in patients undergoing coronary artery bypass graft. METHODS: Consecutive patients undergoing isolated coronary artery bypass graft were prospectively enrolled at three Italian centers. All patients underwent transthoracic echocardiography before the operation. The occurrence of POAF up to discharge was monitored. RESULTS: Overall, a total of 310 patients were included. POAF was demonstrated in 103 patients (33%). At receiver operating characteristic curve analysis, lower global peak atrial longitudinal strain (PALS) values significantly predicted the risk of POAF (area under the curve, 0.74; P<0.001). The optimal cutoff value for the arrhythmia prediction was a global PALS value <28%, with a specificity of 86% and a sensitivity of 36%. The incidence of POAF was 51% in patients with global PALS <28% versus 14% in those with PALS ≥28% (P<0.001), with a POAF-free survival at Kaplan-Meier analysis of 45.4% and 85.7%, respectively (P<0.001). At multivariate analysis, a global PALS <28% carried a 3.6-fold higher risk of POAF (hazard ratio, 3.6 [95% CI, 2.2-5.9]; P<0.001). The risk increase was even higher when PALS <28% was associated with age ≥70 years (adjusted hazard ratio, 11.2 [4.7-26.6], P<0.001). CONCLUSIONS: A presurgery global PALS <28% is a specific parameter to stratify patients at increased risk of POAF after coronary artery bypass graft. This assessment can be useful to identify patients at higher arrhythmic risk in whom perioperative preventive strategies and stricter monitoring aimed at early diagnosing and treating POAF may be applied.

Early effects of left bundle branch area pacing on ventricular activation by speckle tracking echocardiography.

BACKGROUND: Left bundle branch area pacing (LBBAP) is an emerging cardiac pacing modality that preserves fast electrical activation of the ventricles and provides very good electrical measures. Little is known on mechanical ventricular activation during this pacing modality. METHODS: We prospectively enrolled patients receiving LBBAP. Electrocardiographic and electrical parameters were evaluated at implantation, < 24 h and 3 months. Transthoracic echocardiography with strain analysis was performed at baseline and after 3 months, when ventricular mechanical activation and synchrony were analyzed by time-to-peak standard deviation (TPSD) of strain curves for both ventricles. Intraventricular left ventricular (LV) dyssynchrony was investigated by LV TPSD and interventricular dyssynchrony by left ventricle-right ventricle TPSD (LV-RV TPSD). RESULTS: We screened 58 patients with permanent pacing indication who attempted LBBAP. Procedural success was obtained in 56 patients (97%). Strain data were available in 50 patients. QRS duration was 124.1 ± 30.7 ms at baseline, while paced QRS duration was 107.7 ± 13.6 ms (p < 0.001). At 3 months after LBBAP, left ventricular ejection fraction (LVEF) increased from 52.9 ± 10.6% at baseline to 56.9 ± 8.4% (p = 0.004) and both intraventricular LV dyssynchrony and interventricular dyssynchrony significantly improved (LV TPSD reduction from 38.2 (13.6-53.9) to 15.1 (8.3-31.5), p < 0.001; LV-RV TPSD from 27.9 (10.2-41.5) to 13.9 (4.3-28.7), p = 0.001). Ameliorations with LBBAP were consistent in all subgroups, irrespective of baseline QRS duration, types of intraventricular conduction abnormalities, and LVEF. CONCLUSIONS: Echocardiographic strain analysis shows that LBBAP determines a fast and synchronous biventricular contraction with a stereotype mechanical activation, regardless of baseline QRS duration, pattern, and LV function.

Stroke volume index and transvalvular flow rate trajectories in severe aortic stenosis treated with TAVR.

AIMS: The prognostic impact of flow trajectories according to stroke volume index (SVi) and transvalvular flow rate (FR) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains poorly assessed. We evaluated and compared SVi and FR prior and after TAVR for severe AS. METHODS AND RESULTS: Patients were categorized according to SVi (<35 mL/m2) and FR (<200 mL/s). The association of pre- and post-TAVR SVi and FR with all-cause mortality up to 3 years was assessed with multivariable Cox regression models. Among 980 patients with pre-TAVR flow assessment, SVi was reduced in 41.3% and FR in 48.1%. Baseline flow status was not an independent mortality predictor [SVi: hazard ratio (HR) 1.22, 95% confidence interval (CI) 0.85-1.82, FR: HR 0.78, 95% CI 0.48-1.27]. Among 731 patients undergoing early (5 days, interquartile range 2-29) post-TAVR flow assessment, SVi recovered in 40.1% and FR in 49.0% patients with baseline low flow. Reduced FR following TAVR was an independent predictor of mortality (HR 1.67, 95% CI 1.02-2.74), whereas SVi was not (HR 0.97, 95% CI 0.53-1.78). Three-year estimated mortality in patients with recovered FR was lower than that in patients with reduced FR (13.3 vs. 37.7% vs, P = 0.003) and similar to that in patients with normal baseline FR (P = 0.317). CONCLUSION: Baseline flow status was not an independent predictor of mid-term mortality among all-comers with severe AS undergoing TAVR. Flow recovery early after TAVR was frequent. Post-TAVR FR, but not SVi, was independently associated with mid-term all-cause mortality. By impacting flow status, AV replacement modifies the association of flow status with outcomes.

Predictive Value of Echocardiographic Pulmonary to Left Atrial Ratio for In-Hospital Death in Patients with COVID-19.

Background: Echocardiographic Pulmonary to Left Atrial Ratio (ePLAR) represents an accurate and sensitive non-invasive tool to estimate the trans-pulmonary gradient. The prognostic value of ePLAR in hospitalized patients with COVID-19 remains unknown. We aimed to investigate the predictive value of ePLAR on in-hospital mortality in patients with COVID-19. Methods: One hundred consecutive patients admitted to two Italian institutions for COVID-19 undergoing early (<24 h) echocardiographic examination were included; ePLAR was determined from the maximum tricuspid regurgitation continuous wave Doppler velocity (m/s) divided by the transmitral E-wave: septal mitral annular Doppler Tissue Imaging e'-wave ratio (TRVmax/E:e'). The primary outcome measure was in-hospital death. Results: patients who died during hospitalization had at baseline a higher prevalence of tricuspid regurgitation, higher ePLAR, right-side pressures, lower Tricuspid Annular Plane Systolic Excursion (TAPSE)/ systolic Pulmonary Artery Pressure (sPAP) ratio and reduced inferior vena cava collapse than survivors. Patients with ePLAR > 0.28 m/s at baseline showed non-significant but markedly increased in-hospital mortality compared to those having ePLAR ≤ 0.28 m/s (27% vs. 10.8%, p = 0.055). Multivariate Cox regression showed that an ePLAR > 0.28 m/s was independently associated with an increased risk of death (HR 5.07, 95% CI 1.04−24.50, p = 0.043), particularly when associated with increased sPAP (p for interaction = 0.043). Conclusions: A high ePLAR value at baseline predicts in-hospital death in patients with COVID-19, especially in those with elevated pulmonary arterial pressure. These results support an early ePLAR assessment in patients admitted for COVID-19 to identify those at higher risk and potentially guide strategies of diagnosis and care.

Deformation Imaging by Strain in Chronic Heart Failure Over Sacubitril-Valsartan: A Multicenter Echocardiographic Registry.

AIMS: Sacubitril/valsartan has changed the treatment of heart failure with reduced ejection fraction (HFrEF), due to the positive effects on morbidity and mortality, partly mediated by left ventricular (LV) reverse remodelling (LVRR). The aim of this multicenter study was to identify echocardiographic predictors of LVRR after sacubitril/valsartan administration. METHODS AND RESULTS: Patients with HFrEF requiring therapy with sacubitril/valsartan from 13 Italian centres were included. Echocardiographic parameters including LV global longitudinal strain (GLS) and global peak atrial longitudinal strain by speckle tracking echocardiography were measured to find the predictors of LVRR [= LV end-systolic volume reduction ≥10% and ejection fraction (LVEF) improvement ≥10% at follow-up] at 6 month follow-up as the primary endpoint. Changes in symptoms [New York Heart Association (NYHA) class] and neurohormonal activations [N-terminal pro-brain natriuretic peptide (NT-proBNP)] were also evaluated as secondary endpoints; 341 patients (excluding patients with poor acoustic windows and missing data) were analysed (mean age: 65 ± 10 years; 18% female, median LVEF 30% [inter-quartile range: 25-34]). At 6 month follow-up, 82 (24%) patients showed early complete response (LVRR and LVEF ≥ 35%), 55 (16%) early incomplete response (LVRR and LVEF < 35%), and 204 (60%) no response (no LVRR and LVEF < 35%). Non-ischaemic aetiology, a lower left atrial volume index, and a higher GLS were all independent predictors of LVRR at multivariable logistic analysis (all P < 0.01). A baseline GLS < -9.3% was significantly associated with early response (area under the curve 0.75, P < 0.0001). Left atrial strain was the best predictor of positive changes in NYHA class and NT-proBNP (all P < 0.05). CONCLUSIONS: Speckle tracking echocardiography parameters at baseline could be useful to predict LVRR and clinical response to sacubitril-valsartan and could be used as a guide for treatment in patients with HFrEF.

Coronary sinus for cardiac resynchronization therapy: leave it alone and go for the branch! a case report.

Background: Coronary sinus is the target of an increasing number of percutaneous interventional procedures. Thus, in some patients, conventional cardiac resynchronization therapy (CRT) may not be feasible or preferable, and 'alternative' CRT approaches should be applied. Case summary: We present the case of a successful CRT via direct left bundle branch permanent pacing (LBBP) in a patient with relative contraindication to conventional CRT because of previous percutaneous indirect mitral annuloplasty. Discussion: LBBP is emerging as a promising technique for physiological cardiac pacing and CRT. It may represent the technique of choice when coronary sinus is not viable for the implant of a conventional left ventricular catheter.

Atrial thrombosis: Not only left, think also about right!

Atrial fibrillation (AF) is the most common arrhythmia in the general population. Systemic thromboembolism from left atrial appendage (LAA) thrombosis is a well-known complication of AF, whereas thromboembolic complications from a right atrial (RA) thrombus are infrequent. Nevertheless, the prevalence of RA thrombosis is debated; despite having a low prevalence in echocardiographic studies, the higher prevalence found in autoptic studies rises the hypothesis of an under detection of RA clots, possibly related to the limited evaluation of right atrial appendage (RAA) with non-invasive imaging. Here we present a review of the current literature about RA thrombosis, regarding its diagnosis, differentials, and best treatment options.

Sacubitril/valsartan reduces indications for arrhythmic primary prevention in heart failure with reduced ejection fraction: insights from DISCOVER-ARNI, a multicenter Italian register.

Aims: This sub-study deriving from a multicentre Italian register [Deformation Imaging by Strain in Chronic Heart Failure Over Sacubitril-Valsartan: A Multicenter Echocardiographic Registry (DISCOVER)-ARNI] investigated whether sacubitril/valsartan in addition to optimal medical therapy (OMT) could reduce the rate of implantable cardioverter-defibrillator (ICD) indications for primary prevention in heart failure with reduced ejection fraction (HFrEF) according to European guidelines indications, and its potential predictors. Methods and results: In this observational study, consecutive patients with HFrEF eligible for sacubitril/valsartan from 13 Italian centres were included. Lack of follow-up or speckle tracking data represented exclusion criteria. Demographic, clinical, biochemical, and echocardiographic data were collected at baseline and after 6 months from sacubitril/valsartan initiation. Of 351 patients, 225 (64%) were ICD carriers and 126 (36%) were not ICD carriers (of whom 13 had no indication) at baseline. After 6 months of sacubitril/valsartan, among 113 non-ICD carriers despite having baseline left ventricular (LV) ejection fraction (EF) ≤ 35% and New York Heart Association (NYHA) class = II-III, 69 (60%) did not show ICD indications; 44 (40%) still fulfilled ICD criteria. Age, atrial fibrillation, mitral regurgitation > moderate, left atrial volume index (LAVi), and LV global longitudinal strain (GLS) significantly varied between the groups. With receiver operating characteristic curves, age ≥ 75 years, LAVi ≥ 42 mL/m2 and LV GLS ≥-8.3% were associated with ICD indications persistence (area under the curve = 0.65, 0.68, 0.68, respectively). With univariate and multivariate analysis, only LV GLS emerged as significant predictor of ICD indications at follow-up in different predictive models. Conclusions: Sacubitril/valsartan may provide early improvement of NYHA class and LVEF, reducing the possible number of implanted ICD for primary prevention in HFrEF. Baseline reduced LV GLS was a strong marker of ICD indication despite OMT. Early therapy with sacubitril/valsartan may save infective/haemorrhagic risks and unnecessary costs deriving from ICDs.

Left atrial conduit flow rate at baseline and during exercise: an index of impaired relaxation in HFpEF patients.

AIMS: In healthy subjects, adrenergic stimulation augments left ventricular (LV) long-axis shortening and lengthening, and increases left atrial (LA) to LV intracavitary pressure gradients in early diastole. Lower increments are observed in patients with heart failure with preserved ejection fraction (HFpEF). We hypothesized that exercise in HFpEF would further impair passive LV filling in early-mid diastole, during conduit flow from pulmonary veins. METHODS AND RESULTS: Twenty HFpEF patients (67.8 ± 9.8 years; 11 women), diagnosed using 2007 ESC recommendations, underwent ramped semi-supine bicycle exercise to submaximal target heart rate (∼100 bpm) or symptoms. Seventeen asymptomatic subjects (64.3 ± 8.9 years; 7 women) were controls. Simultaneous LA and LV volumes were measured from pyramidal 3D-echocardiographic full-volume datasets acquired from an apical window at baseline and during stress, together with brachial arterial pressure. LA conduit flow was computed from the increase in LV volume from its minimum at end-systole to the last frame before atrial contraction (onset of the P wave), minus the reduction in LA volume during the same time interval; the difference was integrated and expressed as average flow rate, according to a published formula. The slope of single-beat preload recruitable stroke work (PRSW) quantified LV inotropic state. 3D LV torsion (rotation of the apex minus rotation of the base divided by LV length) was also measurable, both at rest and during stress, in 10 HFpEF patients and 4 controls. There were divergent responses in conduit flow rate, which increased by 40% during exercise in controls (+17.8 ± 37.3 mL/s) but decreased by 18% in patients with HFpEF (-9.6 ± 42.3 mL/s) (P = 0.046), along with congruent changes (+1.77 ± 1.13°/cm vs. -1.94 ± 2.73°/cm) in apical torsion (P = 0.032). Increments of conduit flow rate and apical torsion during stress correlated with changes in PRSW slope (P = 0.003 and P = 0.006, respectively). CONCLUSIONS: In HFpEF, conduit flow rate decreases when diastolic dysfunction develops during exercise, in parallel with changes in LV inotropic state and torsion, contributing to impaired stroke volume reserve. Conduit flow is measurable using 3D-echocardiographic full-volume atrio-ventricular datasets, and as a marker of LV relaxation can contribute to the diagnosis of HFpEF.

Usefulness of a multiparametric evaluation including global longitudinal strain for an early diagnosis of acute myocarditis.

Cardiac magnetic resonance imaging (CMRI) represents the main imaging modality for diagnosing acute myocarditis. However, its limited availability could entail missing or delayed diagnosis. A reduction of left ventricular global longitudinal strain (LV GLS) by speckle tracking echocardiography (STE) correlates with amount of oedema in acute myocarditis and here may be early detected. Aim was to evaluate the diagnostic and prognostic role of 3-layers LV GLS in patients with acute myocarditis. Out of 122 patients with suspected acute myocarditis, a total of 86 consecutive patients with CMRI-confirmed acute myocarditis admitted in two Italian institutions were retrospectively screened. Exclusion criteria were met in 29 patients because of poor acoustic window or missing data. A total of 57 patients were then included. Clinical characteristics, laboratory examinations, transthoracic echocardiography data and STE parameters were collected early after hospitalization. In the study population, mean age was 38.8 ± 15.6 years, the prevalence of male gender was 90%. On admission, 22 patients (39%) had fever (body temperature > 37.5 °), mean white blood cell (WBC) count was 10.9 ± 1.7/10^3 and overall LV ejection fraction was 50.1% ± 11.2. An epicardial LV GLS < 18% was present in 74% of patients, and a model including at least one of LV GLS < 18% (absolute value), fever and WBC > 10.0/10^3 was able to identify all patients with CMRI-diagnosed acute myocarditis. An epicardial LV GLS < 15.3% (absolute value) at baseline significantly predicted the lack of myocarditis resolution during follow-up (AUC 0.76, 95% CI 0.58-0.93, p = 0.02). A multiparametric model including epicardial LV GLS, fever and elevated WBC count on admission could be useful for early diagnosing an acute myocarditis, especially when CMRI is not promptly available. Baseline epicardial LV GLS may also identify patients with less-likely myocarditis resolution.

Infective endocarditis complicating COVID-19 pneumonia: a case report.

BACKGROUND: During the COVID-19 outbreak, cardiovascular imaging, especially transoesophageal echocardiography (TOE), may expose healthcare personnel to virus contamination and should be performed only if strictly necessary. On the other hand, transthoracic echocardiography (TTE) and TOE represent the first-line imaging exams for the diagnosis of infective endocarditis (IE). To date, this is the first case of COVID-19 complicated by IE. CASE SUMMARY: We present the case of a 57-year-old man with severe COVID-19 pneumonia requiring mechanical ventilation. During the intensive care unit (ICU) stay, he developed fever and positive haemocoltures for methicillin-resistant Staphylococcus aureus infection. TTE did not identify endocardial vegetations. TOE was then performed and outlined IE of the aortic valve on the non-coronary cusp. Antibiotic therapy was given with progressive resolution of the septic state and improvement of inflammatory signs. After 30 days of ICU stay, the patient was transferred to the Sub-ICU and then to a rehabilitation hospital. A close follow-up has been scheduled: after full recovery, a new echocardiography will be performed (TTE and TOE, if the former is non-conclusive) to consider surgical valve repair in the case of persistence/progression of the valvular lesion or deterioration of the valve function. DISCUSSION: In COVID-19 patients, echocardiography remains the leading imaging exam for the diagnosis of IE. If the suspicion of IE is high, even in this setting of patients, TTE or TOE (if TTE is non-conclusive) are mandatory. A high degree of attention must be paid and appropriate preventive measures taken to avoid contamination of healthcare personnel.

Atrial conduit function quantitation precardioversion predicts early arrhythmia recurrence in persistent atrial fibrillation patients.

AIMS: Atrial fibrillation incidence is increasing due to ageing population and electrical cardioversion (ECV) is overused because of atrial fibrillation recurrences. Study's aim was to evaluate value of novel three-dimensional echocardiographic-derived left atrial conduit (LAC) function quantification in predicting early atrial fibrillation recurrence after ECV. METHODS: We included 106 patients [74 (64-78) years] who underwent ECV for persistent nonvalvular atrial fibrillation. For all clinical data and simultaneous left atrial and left ventricular (LV) three-dimensional full-volume data sets were available before ECV. We computed LAC as: [(LV maximum - LV minimum) - (left atrial maximum - left atrial minimum) volume], expressed as % LV stroke volume. Atrial fibrillation recurrence was checked with Holter monitoring. RESULTS: One month after ECV 66 patients were in sinus rhythm and 40 experienced atrial fibrillation recurrence. Pre-ECV patients with atrial fibrillation recurrence showed higher LAC contribution to LV filling (P < 0.0001) and noninvasively estimated left atrial stiffness (P < 0.0001) compared with sinus rhythm patients. There were no other differences, neither in clinical characteristics nor in LV properties. At multivariate LAC (P < 0.001), left atrial stiffness (P = 0.002) and volume (P = 0.043) predicted early atrial fibrillation relapse, even when compared with other confounding factors. Receiver-operating characteristics area (ROC) analysis confirmed LAC as best atrial fibrillation recurrence predictor (0.84, P < 0.0001), cut-off value more than 54% exhibiting reasonable sensibility-specificity (76-75%). CONCLUSION: Atrial fibrillation makes LV filling dependent on reciprocation between left atrial reservoir/conduit phases. Our data suggest that LAC larger contribution to filling in persistent atrial fibrillation patients reflects left atrial and LV diastolic dysfunction, which skews atrio-ventricular interaction that leads to atrial fibrillation perpetuation, making LAC a powerful atrial fibrillation recurrence predictor after ECV.

Acute Modifications of Left Ventricular Torsional Mechanics Induced by Cardiac Resynchronization Therapy Affect Short-Term Reverse Remodeling.

BACKGROUND: Left ventricular (LV) torsion is an important aspect of cardiac mechanics and is altered in heart failure patients. Cardiac resynchronization therapy (CRT) has a positive effect on LV function, but the exact mechanisms through which it works are not completely depicted. Our aim was to investigate (1) the acute CRT effect on LV torsional mechanics in heart failure patients using 3D speckle tracking echocardiography (3DSTE) and (2) its effect on short-term LV remodeling. Methods and Results: We considered 48 patients (age 72±11 years, 35 men) who received CRT. They underwent 3DSTE during CRT-on (biventricular stimulation) vs. CRT-off (intrinsic conduction/right atrial/ventricular stimulation alone), in a random fashion. Patients were classified as CRT responders based on LV systolic volume reduction ≥15% at 6 months (final population: 31 responders, 17 non-responders). Acute CRT positively affected responders in terms of LV torsion (from 0.32±0.06°/cm CRT-off to 0.41±0.06°/cm CRT-on), but adversely affected non-responders (from 0.54±0.08°/cm CRT-off to 0.28±0.08°/cm CRT-on, interaction P=0.02). A similar trend was confirmed for apical (interaction P<0.04), but not for basal torsion (interaction P=0.351). CONCLUSIONS: CRT has a positive role in acute recovery of LV torsion (particularly in its apical component) in responders, likely modulating the improvement in LV remodeling at early follow-up.

Diagnosis of Heart Failure With Preserved Ejection Fraction: Machine Learning of Spatiotemporal Variations in Left Ventricular Deformation.

BACKGROUND: Stress testing helps diagnose heart failure with preserved ejection fraction (HFpEF), but there are no established criteria for quantifying left ventricular (LV) functional reserve. The aim of this study was to investigate whether comprehensive analysis of the timing and amplitude of LV long-axis myocardial motion and deformation throughout the cardiac cycle during rest and stress can provide more informative criteria than standard measurements. METHODS: Velocity, strain, and strain rate traces were measured from all 18 LV segments by echocardiographic myocardial velocity imaging at rest and during semisupine bicycle exercise in 100 subjects aged 69 ± 7 years, including patients with HFpEF and healthy, hypertensive, and breathless control subjects. A machine-learning algorithm, composed of an unsupervised statistical method and a supervised classifier, was used to model spatiotemporal patterns of the traces and compare the predicted labels with the clinical diagnoses. RESULTS: The learned strain rate parameters gave the highest accuracy for allocating subjects into the four groups (overall, 57%; for patients with HFpEF, 81%), and into two classes (asymptomatic vs symptomatic; area under the curve, 0.89; accuracy, 85%; sensitivity, 86%; specificity, 82%). Machine learning of strain rate, compared with standard measurements, gave the greatest improvement in accuracy for the two-class task (+23%, P < .0001), compared with +11% (P < .0001) using velocity and +4% (P < .05) using strain. Strain rate was also best at predicting 6-min walk distance as an independent reference criterion. CONCLUSIONS: Machine learning of spatiotemporal variations of LV strain rate during rest and exercise could be used to identify patients with HFpEF and to provide an objective basis for diagnostic classification.

Feasibility of cathodic-anodal left ventricular stimulation for alternative multisite pacing.

BACKGROUND: Simultaneous cathodic-anodal capture by a bipole of a cardiac resynchronization therapy (CRT) left-ventricular (LV) catheter may depolarize a larger LV area than conventional multipoint pacing. We evaluated the feasibility of cathodic-anodal LV stimulation. METHODS: In 30 patients undergoing CRT with a quadripolar LV lead, we evaluated the cathodic and anodal capture threshold for each LV pole and compared QRS on electrocardiogram (ECG) during single-point cathodic biventricular stimulation (S-BS), multipoint BS (M-BS), and cathodic-anodal BS (CA-BS). RESULTS: Anodal capture was obtained by three poles in 23/30 patients, by two poles in five, and was not feasible in two. The mean single-point anodal threshold was 3.93 V versus single-point cathodic threshold of 1.95 V. On comparing ECGs, M-BS and CA-BS produced similar QRS wavefront activation in 90% of patients. CONCLUSIONS: CA-BS is feasible and may be used in LV pacing to achieve a different wavefront of electrical activation. Further prospective studies are needed in order to verify the clinical impact of this kind of stimulation.

Machine Learning Analysis of Left Ventricular Function to Characterize Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Current diagnosis of heart failure with preserved ejection fraction (HFpEF) is suboptimal. We tested the hypothesis that comprehensive machine learning (ML) of left ventricular function at rest and exercise objectively captures differences between HFpEF and healthy subjects. METHODS AND RESULTS: One hundred fifty-six subjects aged >60 years (72 HFpEF+33 healthy for the initial analyses; 24 hypertensive+27 breathless for independent evaluation) underwent stress echocardiography, in the MEDIA study (Metabolic Road to Diastolic Heart Failure). Left ventricular long-axis myocardial velocity patterns were analyzed using an unsupervised ML algorithm that orders subjects according to their similarity, allowing exploration of the main trends in velocity patterns. ML identified a continuum from health to disease, including a transition zone associated to an uncertain diagnosis. Clinical validation was performed (1) to characterize the main trends in the patterns for each zone, which corresponded to known characteristics and new features of HFpEF; the ML-diagnostic zones differed for age, body mass index, 6-minute walk distance, B-type natriuretic peptide, and left ventricular mass index (P<0.05) and (2) to evaluate the consistency of the proposed groupings against diagnosis by current clinical criteria; correlation with diagnosis was good (κ, 72.6%; 95% confidence interval, 58.1-87.0); ML identified 6% of healthy controls as HFpEF. Blinded reinterpretation of imaging from subjects with discordant clinical and ML diagnoses revealed abnormalities not included in diagnostic criteria. The algorithm was applied independently to another 51 subjects, classifying 33% of hypertensive and 67% of breathless controls as mild-HFpEF. CONCLUSIONS: The analysis of left ventricular long-axis function on exercise by interpretable ML may improve the diagnosis and understanding of HFpEF.